This is the residual class for all subject matter, not elsewhere classified, relating to electrical generator or motor structure.
(1) Note. This Class was produced in 1953 by making official the unofficial digests which have been established by the Examiners of Division 26 during the period from about 1900 onwards. A caveat is given: while it is believed that the titles and definitions are reasonably accurate, no assurance can be given that all the patents, issued prior to the date of reclassification, are in the proper subclass since only some of these individual patents were read during the reclassification project. Consequently, in making a thorough search in this class, it is advisable to investigate every subclass which may possibly be pertinent and not, in order to shorten the search, to rely upon the principle of superiority of subject matter because of position in the schedule, since that principle is applicable only in classes where each patent has been analyzed and placed in the schedule in accordance with that portion of the disclosed subject matter which is claimed.
(2) Note. Since Class 310 takes, under the class definition, only subject matter relating to electrical generator or motor structure not elsewhere classified, its scope can be determined only by determining the scope of other related classes, which classes are listed below under search class. Also consult the search notes in the definitions of these classes.
(3) Note. Many mechanical classes contain electrical disclosures, as where an electrical machine is disclosed in a mechanical environment, with which it cooperates. Consequently, in appropriate instances, the search must extend to the class or classes which relate to the environment in which the electrical disclosure may be found.

REFERENCES TO OTHER CLASSES

SEE OR SEARCH CLASS:
4, Baths, Closets, Sinks, and Spittoons, subclass 213 for the subject matter of that class having electrical ventilating means.
57, Textiles: Spinning, Twisting, and Twining, subclass 100 for the apparatus of that class having electric motor driving means.
73, Measuring and Testing, appropriate subclasses for mechanical measuring and testing devices having electric motors or generators as part thereof.
84, Music, subclasses 600-722 for electrical musical instruments having means to generate electric currents of particular wave form for use in musical instruments, such as electric organs. Note particularly indented subclasses 1.04+ for electric generators having means which are tuned to resonance.
105, Railway Rolling Stock, subclasses 49+ for electric locomotives.
123, Internal-Combustion Engines, subclass 149 for dynamos in combination with electric ignition systems for internal combustion engines.
124, Mechanical Guns and Projectors, subclass 3 for electromagnetic projectile propelling means.
160, Flexible or Portable Closure, Partition, or Panel, appropriate subclasses, particularly subclass 310 for this subject matter of that class having electric means to operate it.
173, Tool Driving or Impacting, appropriate subclass for an electric motor for driving a tool combined with features peculiar to tool driving. Generally, Class 310 includes motors having a named type of tool as a load. However Class 173 provides for a motor having specific impact delivering relationship to a tool, a passage to deliver cleansing or cooling fluid to a tool work surface, specific structure of a handle to manipulate a tool relative to work or plural motors, one of which is described as driving a tool and another as advancing a tool.
198, Conveyors: Power-Driven, subclass 381, 439 and 619 for electromagnetic conveyors in which the device or material being moved is moved by the action of a magnetic field.
258, Railway Mail Delivery, subclass 4 for magnetic apparatus utilized in railway mail delivery.
307, Electrical Transmission or Interconnections Systems, appropriate subclasses for miscellaneous electric systems having electric generators. Note particularly subclass 82, 84, 151, and 153.
315, Electric Lamp and Discharge Devices: Systems, subclass 55 for electric space discharge devices having combined therewith an integral electric generator or piezoelectric device, subclass 78 for vehicle space discharge device or lamp systems having a vehicle motor or vehicle motion driven generator.
318, Electricity: Motive Power Systems, appropriate
subclasses for electric generator or motor structure having significant circuits connected thereto and for electric motor systems controlled by the control of the motor structure. Also note subclasses 538+ for electric motors, per se, having means to control or adjust them by control of the structure of the motor.
320, Electricity: Battery or Capacitor Charging or Discharging, appropriate subclass for a battery or capacitor charging system that utilizes an electric generator as a source of charge energy.
322, Electricity: Single Generator Systems, appropriate subclasses for electric generator having electric control systems.
323, Electricity: Power Supply or Regulation Systems, subclasses 201-204 for voltage magnitude and phase control systems utilizing motor generator or dynamo electric machine sets.
324, Electricity: Measuring and Testing, appropriate subclasses for electrical measuring or testing devices and systems having electric generators or motors as part thereof. Note particularly subclasses 160+ for speed measuring systems having tachometer generators and subclasses 76.11+ for electric meters having electric generators or motors as part thereof.
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclasses 220+ for electromagnets with armatures (i.e., electric motor of the reciprocating type).
336, Inductor Devices, appropriate subclasses for structure of inductor devices, (e.g., transformers and inductive reactors), particularly for details of induction windings and coils, magnetic cores and cooling means for inductor.
363, Electric Power Conversion Systems, subclasses 102+, 150 and 174+ for electric power conversion systems utilizing dynamoelectric machine converters.
367, Communications, Electrical: Acoustic Wave Systems and Devices, appropriate subclass for compressional wave sensing systems having electro-vibrational transducers and for the corresponding transducers, per se.
416, Fluid Reaction Surfaces (i.e., Impellers), appropriate subclasses for electric motor driven impellers wherein the impeller is claimed as more than a named load.
417, Pumps, subclass 410.1 for pumps having electric drive motors.
505, Superconductor Technology: Apparatus, Material, Process, subclasses 150+ for high temperature (T[subscrpt]c[end subscrpt] 30 K) superconducting devices,
and particularly subclasses 166+ for motors or generators.

This subclass is indented under the class definition. Subject matter relating to assemblages of materials utilized in the fabrication of an electric generator or motor.

SEE OR SEARCH CLASS:
434, Education and Demonstration, subclass 380 for the teaching of the construction of electric motors or generators.

This subclass is indented under the class definition. Subject matter relating to means for converting electrical energy between the electrical and the mechanical state by means of an electromagnetic effect.
(1) Note. Consult the classes referred to in the search notes to this class for other classes having similar subject matter.

SEE OR SEARCH CLASS:
330, Amplifiers, subclass 58 for amplifiers including a rotating dynamoelectric machine as the active element thereof. See the Notes and Search Notes thereunder.
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclasses 220+ for electromagnet with armature.
367, Communications, Electrical: Acoustic Wave Systems and Devices, subclasses 140+ for similar subject matter utilized in compressional wave sensing and detecting systems.

This subclass is indented under subclass 10. Subject matter
having a fluid which is significantly related to the apparatus in a manner other than cooling or lubrication.
(1) Note. This subclass relates, for example, to dynamoelectric machinery in which the fluid may be conductive to electricity and to dynamoelectric machinery in which the fluid serves as a kinetic element to exert mechanical force.

SEE OR SEARCH CLASS:
324, Electricity: Measuring and Testing, subclasses 92+ for the structure of integrating electric meters which utilize a conductive or genetic fluid.
376, Induced Nuclear Reactions: Processes, Systems, and Elements, subclasses 100+ for thermonuclear reactions utilizing conducting gases as fuels.

This subclass is indented under subclass 10. Subject matter in which the dynamoelectric effect takes place between two relatively movable elements which are constrained to substantially straight line motion.
(1) Note. This subclass relates, for example, to devices which normally act only in a single direction such as an aircraft or projectile launching mechanism.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 15+ for dynamoelectric devices in which the elements move in a straight line and reciprocate back and forth.

SEE OR SEARCH CLASS:
104, Railways, subclass 282 for a railway vehicle and track having a linear motor which propels and suspends the vehicle and subclasses 290+ for a railway vehicle and track claimed in combination with a linear motor.
124, Mechanical Guns and Projectors, subclass 3 for electromagnetic projectile propelling means.
318, Electricity: Motive Power Systems, subclass 38, 135 and 687 for this subject matter in combination with an electrical system.

This subclass is indented under subclass 12. Subject matter in which both the fixed and the movable elements of the dynamoelectric device are provided with current carrying conductors or inductor.

SEE OR SEARCH CLASS:
104, Railways, subclass 292 for a railway vehicle and track claimed in combination with a linear motor having fixed and movable wound elements on the track and vehicle, respectively.

This subclass is indented under subclass 12. Subject matter in which the fixed and the movable elements of the dynamoelectric device are concentric and consist of a hollow winding and a plunger type armature passing thereunto.

SEE OR SEARCH CLASS:
124, Mechanical Guns and Projectors, subclass 3 for electromagnetic guns and projectors.
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclasses 255+ for similar subject matter.

This subclass is indented under subclass 10. Subject matter in which the movable element of the dynamoelectric device moves to and fro along a straight line path or along an arcuate path which is so short as to be substantially a straight line.
(1) Note. The term reciprocating, as used in this subclass, is limited to straight line motion or nonstraight line motion which is of such short extent that the interrelationship between the moving elements of the dynamoelectric device is substantially the same as if the motion were only along a straight line path.

SEE OR SEARCH THIS CLASS, SUBCLASS:
12 for straight line motion which is unidirectional and does not produce to-and-fro motion.
subclasses 36+ for dynamoelectric devices which constrain the elements to oscillate to-and-fro motion and in which the extent of motion is such that some provision must be made for the nonlinear interaction between the relatively moving elements of the dynamoelectric device.

SEE OR SEARCH CLASS:
30, Cutlery, subclass 45 for this subject matter combined with a razor.
84, Music, subclasses 725+ for this subject matter utilized in an electrical musical instrument, such as an electric guitar.
209, Classifying, Separating, and Assorting Solids, subclass 360 for this subject matter combined with a vibratory separator.
236, Automatic Temperature and Humidity Regulation, subclass 75 for this subject matter in an automatic temperature or humidity regulation system.
246, Railway Switches and Signals, subclasses 225+ for this subject matter in a railway switching or signaling system.
318, Electricity: Motive Power Systems, subclass 37, 118, 119+, 556+, and 686 for this subject matter in an electric motor control system.
322, Electricity: Single Generator Systems, subclass 3 for this subject matter utilized in a single generator system.
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclasses 87+ for this subject matter combined with a periodically actuated switch.
417, Pumps, subclasses 416+ for a reciprocating electric motor driving a reciprocating pump.

This subclass is indented under subclass 15. Subject matter having means for altering the temperature conditions of the machine.
(1) Note. This subclass relates, for example, to reciprocating motors having cooling means.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 52+ for rotary electric motors having cooling means.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclasses 55+ for inductor devices with temperature modifying means (cooling means).

This subclass is indented under subclass 15. Subject matter having means for performing a function which is in addition to the function of the reciprocating dynamo device.

This subclass is indented under subclass 17. Subject matter having means for regulating the rate of motion or the duration of a period of inactivity of the reciprocating dynamoelectric device.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 119+ for similar subject matter having a significant electrical circuit.

This subclass is indented under subclass 17. Subject matter having means for mechanically transforming the character or extent of motion delivered by or imparted to the dynamoelectric device.

SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, appropriate subclasses for mechanical movements for converting one type of motion to another type of motion.

This subclass is indented under subclass 20. Subject matter in which the moving element of the dynamoelectric device is supported either by a leaf spring or by a pivot located at a distance from the line of relative motion of the dynamoelectric device which is large relative to the extent of movement.

This subclass is indented under subclass 21. Subject matter having a plurality of movable elements or armatures.

This subclass is indented under subclass 20. Subject matter in which the relatively movable parts of the dynamoelectric device are concentric and consist of a hollow winding and a plunger type armature passing thereunto.

This subclass is indented under subclass 23. Subject matter having a plurality of plunger type armatures.

This subclass is indented under subclass 15. Subject matter in which the movable parts of the dynamoelectric device reciprocate or vibrate at a frequency which is determined by the natural period of the mounting means for the movable parts.
(1) Note. This subclass relates, for example, to reciprocating motors having a tuned reed type of armature. Generally, but not invariably, a state of resonance exists
between the natural period of the movable armature and the impulses of an electric field.

SEE OR SEARCH THIS CLASS, SUBCLASS:
26 for similar subject matter utilizing magnetostrictive means.

SEE OR SEARCH CLASS:
331, Oscillators, subclass 156 for electrical oscillators utilizing an electromechanical resonator of the vibrating reed or string type (e.g., tuning fork).

This subclass is indented under subclass 15. Subject matter having means to produce motion or electric energy by the action of magnetostriction.
(1) Note. Magnetostriction is a property exhibited by some materials which change their physical size or shape under the action of magnetic fields or which produce magnetic fields when physically stressed.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclass 118 for magnetostrictive motor systems.
331, Oscillators, subclass 157 for electrical oscillators utilizing an electromechanical resonator of the magnetostrictive type.
333, Wave Transmission Lines and Networks, subclass 148 and 201 for coupling networks having magnetostrictive elements as parts thereof.
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclass 215 for this subject matter
367, Communications, Electrical: Acoustic Wave Systems and Devices, subclass 156 and 168 for magnetostrictive transducers used in underwater compressional wave production or sensing.

This subclass is indented under subclass 15. Subject matter
in which both of the relatively movable parts of the dynamoelectric device include current carrying conductors or inductor.

This subclass is indented under subclass 15. Subject matter which is of the direct connected type.
(1) Note. This subclass relates, for example, to reciprocating electric motors where the reciprocating armature is directly connected to a source or absorber of motion.

This subclass is indented under subclass 28. Subject matter in which the relatively movable elements of the dynamoelectric device are supported by either of a leaf spring or a pivot located at a point remote from the line of motion of the dynamoelectric device when compared to the extent of motion of the latter.

SEE OR SEARCH THIS CLASS, SUBCLASS:
25 and 32, for this subject matter.

This subclass is indented under subclass 28. Subject matter in which the relatively movable parts of the dynamoelectric device are concentric and consist of a hollow winding and a plunger type armature passing thereunto.

SEE OR SEARCH THIS CLASS, SUBCLASS:
23 and 34+, for similar subject matter.

This subclass is indented under subclass 15. Subject matter
in which the relative motion of the elements of the dynamoelectric device actuates an electrical switch which controls the flow of currents to windings associated with one of such elements.

SEE OR SEARCH CLASS:
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclasses 87+ for periodic electromagnetic switches.
340, Communications: Electrical, subclass 384.1, especially subclasses 388.7 and 397.3 for interrupter in diaphragm and percussion type sound producer, respectively.

This subclass is indented under subclass 31. Subject matter in which the movable element of the dynamoelectric device is supported or carried by either a reed spring or a pivot located at a distance from the line of motion of a device which is large relative to the extent of motion of such element.

SEE OR SEARCH THIS CLASS, SUBCLASS:
21 and 29, for this subject matter.

This subclass is indented under subclass 32. Subject matter having plural armatures.

This subclass is indented under subclass 31. Subject matter in which the relatively movable elements of the dynamoelectric device include a hollow winding and an axial plunger or core embraced by such winding.

This subclass is indented under subclass 34. Subject matter having plural hollow windings and having means to energize the plural windings in sequence or at different times.

This subclass is indented under subclass 10. Subject matter in which the line of motion between the relatively movable elements of the dynamoelectric device lies along the arc of a portion of a circle and having means to accommodate such motion, over and above the means necessary for relative motion along a straight line.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 15+ for dynamoelectric devices having oscillate relative motion, but in which the extent of such motion does not require modification of the device because of the nonlinearity of the motion.
subclasses 40+ for dynamoelectric devices having arcuate relative motion in which the motion exceeds 3605.

SEE OR SEARCH CLASS:
236, Automatic Temperature and Humidity Regulation, subclass 75 for the subject matter of that class having oscillating electric motors.
318, Electricity: Motive Power Systems, subclass 37, 119+, 556, and 686 for oscillating electric motor systems.
322, Electricity: Single Generator Systems, subclass 3 for oscillating generator systems.

This subclass is indented under subclass 36. Subject matter in which the relative motion between the elements of dynamoelectric device is communicated to a load by means of mechanical means which alter the character or amplitude of such motion.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 80+ for similar subject matter.

SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, appropriate subclasses for mechanical movements.

This subclass is indented under subclass 36. Subject matter in which the relative motion of the elements of the dynamoelectric device is transmitted to a load by an immediate attachment and without intervening transmitting parts or mechanisms.

This subclass is indented under subclass 36. Subject matter in which an electric switch or its equivalent controls the flow of currents through windings associated with one of the relative movable elements of the dynamoelectric device.

SEE OR SEARCH CLASS:
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclasses 87+ for vibratory switches.
340, Communications: Electrical, subclass 384.1, especially subclasses 388.7 and 397.3 for interrupter in diaphragm and percussion type sound producer, respectively.

This subclass is indented under subclass 10. Subject matter in which the line of motion between the relatively movable elements of the dynamoelectric device lies along at least 360 degrees of the arc of a circle.
(1) Note. This subclass relates, for example, to dynamoelectric devices where the motion is continuous rotation in one direction, or where the rotation in one direction progresses for several turns before the rotation
reverses in direction.

SEE OR SEARCH CLASS:
314, Electric Lamp and Discharge Devices: Consumable Electrodes, subclasses 69+ for arc lights having rotary electric motor means to feed the carbons.
362, Illumination, subclass 193 for bicycle lights having an electric generator driven by the motion of the vehicle.
417, Pumps, subclass 410.1 for pumps having rotary electric drive motors.

This subclass is indented under subclass 40. Subject matter including a linkage, usually between the motor and its support, to cause the complete motor to rotate or oscillate with respect to its support in response to the rotary motion of the motor rotor or armature.

SEE OR SEARCH CLASS:
416, Fluid Reaction Surfaces (i.e., Impellers), subclass 100 for oscillating electric fans where significant details of the impeller are recited.

This subclass is indented under subclass 40. Subject matter in which means are provided to impart initial rotation to the rotary element of the dynamoelectric device other than by the dynamoelectric effect.
(1) Note. The initial rotation, for example, may be effected by a hand crank.

This subclass is indented under subclass 40. Subject matter in which separate means are provided, or in which one or more parts are modified, to facilitate the process of (1) associating together, (2) casting of molten metal, or (3) surface cutting, of one or more of component parts.

SEE OR SEARCH CLASS:
29, Metal Working, subclasses 596+ for miscellaneous methods of making dynamoelectric devices. Also consult the extensive search notes to these subclasses for the location of related art.

This subclass is indented under subclass 40. Subject matter in which one or more component parts of the dynamo or electric device are fabricated of a plastic nonmetal, as by a casting or pressure molding operation.

SEE OR SEARCH CLASS:
65, Glass Manufacturing, appropriate subclass for a process of working or treating glass.
264, Plastic and Nonmetallic Article Shaping or Treating: Processes, appropriate subclasses for methods for working or shaping plastic materials.
425, Plastic Article or Earthenware Shaping or Treating: Apparatus, appropriate subclasses for molding apparatus for shaping or reshaping plastic materials.

This subclass is indented under subclass 40. Subject matter in which one or more of the component parts of the dynamoelectric device are fabricated or powdered or sintered metal particles.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, subclasses 228+ for sintered metal powder compositions, such as those resulting from a process provided for in Class 419, Powder Metallurgy Processes and subclasses 255+ for metal containing powders.
419, Powder Metallurgy Processes, appropriate subclasses for processes of making articles by pressing and/or sintering metal particles.

This subclass is indented under subclass 40. Subject matter in which one or more parts of the dynamoelectric device have been treated with liquid material so as to retain within and/or on the surface of such parts residual amounts of such liquid material.
(1) Note. The coating or impregnation, for example, may be for the windings and may serve to exclude or displace moisture therefrom.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclass 205 for inductor having coil turns cemented or embedded in plastic.
427, Coating Processes, subclasses 58+ for processes of coating, per se, of electrical products.

This subclass is indented under subclass 40. Subject matter in which one of the relatively movable elements of the dynamoelectric device consist merely of magnetizable material and is free of inductor or conductive windings.
(1) Note. Since the dynamoelectric effect is necessary one of the attraction of the magnetizable material by magnetic pole induced therein, the devices of this subclass are generally motors.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 168+ for inductor type generators.

This subclass is indented under subclass 46. Subject matter in which the dynamoelectric device is arranged to be transported or operated while held in the hand.
(1) Note. Many of the motors of this subclass are disclosed as operating hair clippers or moving cutter type of shavers.

SEE OR SEARCH THIS CLASS, SUBCLASS:
50 for portable or hand held dynamoelectric devices other than magnetic motors.

SEE OR SEARCH CLASS:
30, Cutlery, subclasses 43+ for dry shavers.
74, Machine Element or Mechanism, subclass 16 for power tables and stands.
318, Electricity: Motive Power Systems, subclass 17 for this subject matter having a significant electric circuit.

This subclass is indented under subclass 46. Subject matter in which the motor is combined with additional features over and above those required for its operation as a motor.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 17+ for similar combinations with reciprocating type dynamoelectric devices.
subclasses 66+ for similar combinations with rotary type dynamoelectric devices, other than magnetic motors.

This subclass is indented under subclass 46. Subject matter having means to cause rotation between two or more positions of rest and to stop at a selected position of rest until an adjustment is made which causes rotation to another position of rest.
(1) Note. This subclass relates, for example, to magnetic motors which are in the nature of servo motors or follow-up devices.

This subclass is indented under subclass 40. Subject matter in which the dynamoelectric device is arranged to be transported or operated while held in the hand.

SEE OR SEARCH THIS CLASS, SUBCLASS:
47 for portable or hand type rotary magnetic motors.

SEE OR SEARCH CLASS:
173, Tool Driving or Impacting, appropriate subclass for a tool driving or impacting device and including hand manipulated tool driving or impacting means. An electric motor described as for tool driving is classified in Class 173 if specific impact delivering relationship to a tool is claimed, a passage to deliver cleansing or cooling fluid to a tool work surface is claimed or specific structure of a handle to manipulate a tool relative to work is claimed.
315, Electric Lamp and Discharge Devices: Systems, subclass 33 for electric lamp or space discharge devices having combined therewith some circuit element structure such as the generator, where the combination is adapted to be portable.
318, Electricity: Motive Power Systems, subclass 17 for this subject matter in combination with a significant system.
322, Electricity: Single Generator Systems, subclass 1 for portably mounted single generator systems.

This subclass is indented under subclass 40. Subject matter having means to inhibit, damp-out or insulate against the transmission of sound or mechanical oscillations or vibrations of the parts of the dynamoelectric device.

SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, subclass 573 for flywheel or rotor balancing means and subclass 574 for flywheel or rotor vibration damping means.
336, Inductor Devices, subclass 100 for inductor devices such as transformers, having means to suppress vibration.

This subclass is indented under subclass 40. Subject matter having means either to cool the dynamoelectric device or to contact a liquid or gas with the dynamoelectric device.

SEE OR SEARCH THIS CLASS, SUBCLASS:
16 and 227, for this subject matter.

SEE OR SEARCH CLASS:
105, Railway Rolling Stock, subclass 59 for electric locomotives having motor coolers.
165, Heat Exchange, subclasses 47+ for a structurally installed heat exchange means.
336, Inductor Devices, subclasses 55+ for inductor devices with temperature modifying means (cooling means).

This subclass is indented under subclass 52. Subject matter having control means.
(1) Note. This subclass relates, for example, to electric motors having means to control the amount of cooling or to control the amount of fluid contact.

This subclass is indented under subclass 52. Subject matter in which the cooling fluid or contacting fluid is a liquid under normal atmospheric temperatures and pressures.

SEE OR SEARCH THIS CLASS, SUBCLASS:
11 for this subject matter where the fluid is a conducting or kinetic fluid and subclass 87 for this subject matter where the dynamoelectric device is submersible in a liquid.

This subclass is indented under subclass 52. Subject matter in which the cooling fluid or contacting fluid is a gas under normal atmospheric temperatures and pressures and is other than atmospheric air.
(1) Note. This subclass relates, for example, to dynamoelectric devices having hydrogen cooling means. Hydrogen has a thermal conductivity greater than other common gases.

This subclass is indented under subclass 52. Subject matter having means to remove impurities from or otherwise condition the gas used as a cooling or contacting fluid.
(1) Note. This subclass relates, for example, to dynamoelectric devices having cooling means in the form of an air blast means and having filter means in the air passage.

SEE OR SEARCH THIS CLASS, SUBCLASS:
55 for this subject matter where the gas is a nonatmospheric gas.

SEE OR SEARCH CLASS:
96, Gas Separation: Apparatus, for apparatus for gas separation, per se.

This subclass is indented under subclass 52. Subject matter in which a fluid is retained in the cooling system of a dynamoelectric device without loss or replacement, so as to serve merely as a heat transfer medium.

SEE OR SEARCH CLASS:
165, Heat Exchange, subclass 104.11 for a heat exchanging system having an intermediate fluent material receiving and discharging heat.

This subclass is indented under subclass 52. Subject matter relating to the circulation of cooling or other fluid through the dynamoelectric device.
(1) Note. The fluid may, for example, be forced through the dynamoelectric device.

This subclass is indented under subclass 58. Subject matter having plural dynamoelectric units, or having plural paths through which the fluid may flow.

This subclass is indented under subclass 58. Subject matter having means integral with the dynamoelectric device for forcing fluid through the dynamoelectric device.
(1) Note. The means, for example, may be vanes attached to the rotor of the dynamoelectric device.

SEE OR SEARCH CLASS:
417, Pumps, subclasses 366+ and 410.1+ for electric motor driven pumps where the pump is of general utility and not used merely to cool the electric motor.

This subclass is indented under subclass 60. Subject matter having means in the rotor of the dynamoelectric device to provide a duct or channel to accommodate a fluid flow along the duct or channel.
(1) Note. Frequently, for example, a radial or circumferential inclination of this duct or channel is sufficient to induce flow of fluid therethrough without other means for maintaining the flow.

This subclass is indented under subclass 60. Subject matter in which the pump or other propelling means for the cooling or contacting fluid is located downstream from the dynamoelectric device.

This subclass is indented under subclass 60. Subject matter in which the pump or other propelling means for the cooling or contacting fluid is located upstream from the dynamoelectric device.

This subclass is indented under subclass 58. Subject matter having means to facilitate, augment, or modify the transfer of heat from the dynamoelectric device from the cooling fluid or between different portions of the dynamoelectric device.

SEE OR SEARCH CLASS:
165, Heat Exchange, subclass 185 for a heat transmitter (e.g., fin), per se.

This subclass is indented under subclass 64. Subject matter in which the means for facilitating, augmenting, or modifying the transfer of heat includes devices for maintaining parts of the dynamoelectric device out of contact with each other, so that either the cooling fluid has access to enlarged areas of the device or face-to-face heat transmitting contact is avoided.
(1) Note. The means for spacing the parts, for example, may provide cooling passages between laminae or coils.

This subclass is indented under subclass 40. Subject matter
combined with some other type of subject matter.
(1) Note. The search should in all appropriate cases be continued in the class which relates to the environment with which the dynamoelectric device is combined.

This subclass is indented under subclass 66. Subject matter in which the other subject matter is in built or incorporated into the dynamoelectric device.

SEE OR SEARCH CLASS:
105, Railway Rolling Stock, subclass 53 for electrical locomotives of the type in which the driving wheel is part of the electric motor.
180, Motor Vehicles, subclass 65.6 for a motor vehicle provided with an electric motor for driving it and wherein the motor may be affixed to a wheel of the vehicle.
362, Illumination, subclass 193 for bicycles light systems in which the bicycle light and an electric wheel driven generator are combined.

This subclass is indented under subclass 66. Subject matter in which the other subject matter is one or more electric circuit elements.

SEE OR SEARCH CLASS:
318, Electricity: Motor Power Systems, subclasses 830+ for induction motor systems having circuit control means built into the induction motor.

This subclass is indented under subclass 68. Subject matter having a shaft driven switch.
(1) Note. This subclass relates, for example, to blasting generators having a shaft driven switch.

This subclass is indented under subclass 69. Subject matter having a distributor or timer.
(1) Note. This subclass relates, for example, to ignition magnetos having a distributor switch or a timer switch as an integral part thereof.

This subclass is indented under subclass 68. Subject matter having connectors, terminals or lead-ins.

SEE OR SEARCH CLASS:
191, Electricity: Transmission to Vehicles, subclasses 2+ for electric motor traction systems having a system of distribution to energize the electric motor.
336, Inductor Devices, subclass 107 and 192 for inductive devices with connectors or having windings with terminals, taps or coil conductor end anchoring means, respectively.
439, Electrical Connectors, appropriate subclasses for a connector terminal, or lead-in, per se.

This subclass is indented under subclass 68. Subject matter having an impedance device.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, appropriate subclasses for electric motors having significant electric circuits.

This subclass is indented under subclass 68. Subject matter having illuminating devices.

SEE OR SEARCH CLASS:
362, Illumination, appropriate subclasses for illuminating devices, per se, and for combined structure of illuminating and nonilluminating device.

This subclass is indented under subclass 66. Subject matter in which the other element is an inertia or flywheel device.

SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, subclasses 572+ for flywheels, per se, and for rotors, per se.

This subclass is indented under subclass 66. Subject matter in which the other element is a drive mechanism.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 118+ for similar subject matter.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, subclass 149 for internal combustion engines having generator igniting devices which are driven by the engine.
246, Railway Switches and Signals, subclass 245 for electric railway switching and signaling systems having a car actuated generator.
318, Electricity: Motive Power Systems, subclasses 9+ for this subject matter having a significant electric circuit.

This subclass is indented under subclass 75. Subject matter having a brake and a clutch.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 92+ for torque transmitting electrodynamic clutches or brakes, per se, and for the electric control systems for these devices.

SEE OR SEARCH CLASS:
192, Clutches and Power-Stop Control, appropriate subclass for miscellaneous clutch and brake systems.
318, Electricity: Motive Power Systems, subclasses 362+ and the other classes and subclasses referred to in the search notes of these subclasses for this subject matter having a significant electric circuit.

This subclass is indented under subclass 75. Subject matter having a brake.
(1) Note. Consult the search notes to subclass 76, above.

This subclass is indented under subclass 75. Subject matter having a clutch.
(1) Note. Consult the search notes to subclass 76, above.

This subclass is indented under subclass 75. Subject matter having a shaft and armature timing or phasing connection.
(1) Note. This subclass relates, for example, to dynamoelectric devices having means for adjusting the space-phase of the dynamoelectric device with respect to its source of mechanical energy or its mechanical load.

This subclass is indented under subclass 75. Subject matter having motion conversion means.

SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, appropriate subclasses for mechanical movements.
318, Electricity: Motive Power Systems, subclass 14 for this subject matter having a significant circuit.

This subclass is indented under subclass 80. Subject matter having an unbalanced weight.
(1) Note. The subclass relates, for example, to dynamoelectric devices of the rotary type which have an unbalanced rotor and act to produce vibratory motion.

SEE OR SEARCH CLASS:
601, Surgery: Kinesitherapy, subclasses 67+ for subject matter utilized for kinesitherapy.

This subclass is indented under subclass 80. Subject matter having a swash plate.

SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, subclass 60 for swash plate mechanisms, per se.

This subclass is indented under subclass 80. Subject matter having gearing.

SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, subclasses 640+ for gearing, per se.
318, Electricity: Motive Power Systems, subclasses 12+ and 15 for this subject matter having a significant electric circuit.
475, Planetary Gear Transmission Systems or Components, for planetary gearing.

This subclass is indented under subclass 80. Subject matter relating to impulse couplings.

This subclass is indented under subclass 66. Subject matter having mechanical shields or protectors.

SEE OR SEARCH CLASS:
361, Electricity: Electrical Systems and Devices, subclasses 600+ and the classes referred to in the search notes to Class 361, subclasses 600+ for housings for electrical apparatus.

This subclass is indented under subclass 85. Subject matter having a shield in the air gap.

This subclass is indented under subclass 85. Subject matter having means to render the device submersible.

This subclass is indented under subclass 85. Subject matter having means to render the device dirt, moisture or explosion proof.
(1) Note. A dynamoelectric device may be rendered explosion proof by filling all voids within the device in such manner that the passages are not sufficiently large to support a flame or explosion, because of the lose of energy from the flame or explosion by radiation to the surrounding mass of solid material.

SEE OR SEARCH THIS CLASS, SUBCLASS:
87 for this subject matter when submersible.

This subclass is indented under subclass 85. Subject matter relating to housings, windows or covers.

SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, subclasses 50+ for miscellaneous boxes and housings for electrical apparatus having only a single type of electrical apparatus within the box or housing. Also consult the search notes to Class 174, subclasses 50+ for related art.

This subclass is indented under subclass 66. Subject matter having means to adjust a bearing or an air cap or to lubricate a bearing.

SEE OR SEARCH CLASS:
384, Bearings, appropriate subclasses for bearings or bearings and means to lubricate the bearing.

Magnetic bearing:
This subclass is indented under subclass 90. Subject matter wherein the bearing has an induction field.

SEE OR SEARCH CLASS:
219, Electric Heating, subclasses 647+, especially indented subclass 648 for electrically heating a body while magnetically suspending or supporting it.
250, Radiant Energy, subclasses 201+ for photoelectric cell systems adapted for use in magnetic suspensions.
310, Electrical Generator or Motor Structure, subclass 166 for means for suspending a body by means of an induction field.
324, Electricity: Measuring and Testing, subclass 151 for electric meters having magnetic suspensions.
361, Electricity: Electrical Systems and Devices, subclasses 139+ for control circuits for electromagnetic devices, especially subclasses 143+ or magnetic retention.

This subclass is indented under subclass 66. Subject matter having supports.

SEE OR SEARCH CLASS:
248, Supports, appropriate subclass for miscellaneous supports of general application.

This subclass is indented under subclass 40. Subject matter relating to torque transmitting clutches and brakes and the systems utilized with torque transmitting clutches.
(1) Note. The torque which is transmitted in the devices of this and indented subclasses is transmitted through the medium of an electromagnetic field. When the torque is transmitted by frictional contact, consult the classes referred to below under Search Class.

SEE OR SEARCH CLASS:
73, Measuring and Testing, subclasses 862+ for torque type
dynamometers, utilized in testing, some of which utilize electromagnetic clutches and brakes.
188, Brakes, for mechanical brakes. Note subclasses 158+ for electric operators for such brakes.
192, Clutches and Power-Stop Control, appropriate subclasses for mechanical clutches and for systems utilizing a mechanical clutch as part thereof.
318, Electricity: Motive Power Systems, appropriate subclass for electric motor systems having an electromagnetic clutch or brake as part thereof. Also consult the extensive search notes to the Class Definition of Class 318 (note particularly the References To Other Classes) for related art.
322, Electricity: Single Generator Systems, subclass 12 for single generator system having an electromagnetic clutch for connecting and disconnecting the generator from the source of power, and subclass 40 for similar subject matter and which the electromagnetic clutch is utilized to control the speed of the generator.
361, Electricity: Electrical Systems and Devices, subclass 207 for electrostatic relay circuits, such as those which utilize piezoelectric devices or the Winslow effect.
417, Pumps, subclasses 223+ for pumps having dynamoelectric clutches for connecting and disconnecting the pump from a source of mechanical power.
464, Rotary Shafts, Gudgeons, Housings, and Flexible Couplings for Rotary Shafts, appropriate subclasses for a flexible coupling between a shaft and driven member.

This subclass is indented under subclass 92. Subject matter utilized for braking.
(1) Note. Consult the search notes to subclass 92, above.

SEE OR SEARCH CLASS:
188, Brakes, subclass 267 for a brake or shock absorber using magnetic flux to retard motion.

This subclass is indented under subclass 92. Subject matter having means to automatically control it.
(1) Note. Consult the search notes to subclass 92, above.

This subclass is indented under subclass 94. Subject matter automatically responsive to speed.

SEE OR SEARCH CLASS:
361, Electricity: Electrical Systems and Devices, subclasses 236+ for miscellaneous speed controlled systems.

This subclass is indented under subclass 92. Subject matter having drive mechanism, other than the torque transmitting clutch or brake.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 75+ for similar subject matter utilized in rotary electric motors and generators.

This subclass is indented under subclass 96. Subject matter having an output bias or resistance device.

This subclass is indented under subclass 96. Subject matter having a drive motor.

SEE OR SEARCH CLASS:
477, Interrelated Power Delivery Controls, Including Engine
Control, for interrelated control between an engine and a transmission, clutch, or brake.

This subclass is indented under subclass 96. Subject matter having gearing means.

SEE OR SEARCH THIS CLASS, SUBCLASS:
83 for similar subject matter in rotary dynamoelectric machinery.

This subclass is indented under subclass 96. Subject matter having a mechanical clutch.

SEE OR SEARCH CLASS:
192, Clutches and Power-Stop Control, appropriate subclasses for mechanical clutches, per se.

This subclass is indented under subclass 92. Subject matter having plural units.

This subclass is indented under subclass 92. Subject matter which is adapted to be used with a generator motor.

This subclass is indented under subclass 92. Subject matter in which the torque is transmitted through a magnetic field.

SEE OR SEARCH THIS CLASS, SUBCLASS:
92 through 102, for torque transmitting clutches in which the torque is transmitted through an electrostatic field or by means of the Winslow effect.

This subclass is indented under subclass 103. Subject matter having a shield in the air gap.
(1) Note. The shield may, for example hermetically separate the rotor from the stator.

This subclass is indented under subclass 103. Subject matter in which the magnetic field induces eddy or other induced currents.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 166+ for alternating current induction motors.

This subclass is indented under subclass 105. Subject matter having a magnetic reluctance feature.

This subclass is indented under subclass 105. Subject matter having collection means for the induced currents.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 219+ for current collectors, per se.

This subclass is indented under subclass 107. Subject matter having means to deliver the current which is collected to an external device.
(1) Note. The external device, for example, may be a variable resistance.

This subclass is indented under subclass 108. Subject matter in which the external device is an electric motor.

This subclass is indented under subclass 108. Subject matter in which the external device is an impedance.

This subclass is indented under subclass 40. Subject matter relating to the modification of generated wave forms.
(1) Note. This subclass relates, for example, to wave generators and to generators having a special distribution of coil windings to obtain a specific wave form.

SEE OR SEARCH CLASS:
84, Music, subclasses 725+ for electrical and musical instruments having generator means to generate a particular way form, such as electric organs.

This subclass is indented under subclass 40. Subject matter relating to plural units which are structurally united.
(1) Note. This subclass relates, for example, to generators structurally united with exciters.

SEE OR SEARCH CLASS:
322, Electricity: Single Generator Systems, subclass 13 for generator systems having an electric motor to drive the generator.
323, Electricity: Power Supply or Regulation Systems, subclass 202 for balancer set systems.

This subclass is indented under subclass 112. Subject matter relating to motor generator sets.

SEE OR SEARCH CLASS:
363, Electric Power Conversion Systems, subclass 104 for dynamoelectric machine converter systems having plural structurally united units.

This subclass is indented under subclass 40. Subject matter having plural rotary elements.

SEE OR SEARCH THIS CLASS, SUBCLASS:
112 for subject matter having plural distinct units.

This subclass is indented under subclass 114. Subject matter in which both the field and the armature of a dynamoelectric device rotate.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclass 539 for
this subject matter in combination with a significant electric circuit.
388, Electricity: Motor Control Systems, subclasses 835+ for running-speed control systems in which the field as well as the armature may be rotatable.

This subclass is indented under subclass 115. Subject matter in which the amount of motion is limited.

This subclass is indented under subclass 116. Subject matter having means to mechanically bias one or both of the rotatable elements.

This subclass is indented under subclass 115. Subject matter having drive mechanism to interconnect the field and armature.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 75+ for similar subject matter.

This subclass is indented under subclass 118. Subject matter in which the interconnecting mechanism is a fluid drive mechanism.

SEE OR SEARCH THIS CLASS, SUBCLASS:
11 for dynamoelectric devices having a kinetic fluid.

This subclass is indented under subclass 118. Subject matter in which the drive mechanism is friction drive mechanism.

This subclass is indented under subclass 118. Subject matter in which the interconnection drive mechanism includes a mechanical element whose motion is controlled by means other than the armature or the field.
(1) Note. The mechanical element, for example, may be an escapement.

This subclass is indented under subclass 121. Subject matter in which the mechanically controlled element is controlled by an additional dynamoelectric machine.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 112+ for plural units which are structurally united.

This subclass is indented under subclass 121. Subject matter in which the mechanically controlled element is controlled by means of a friction brake.

SEE OR SEARCH THIS CLASS, SUBCLASS:
77 for similar subject matter.

This subclass is indented under subclass 114. Subject matter having plural short circuited rotary elements.

This subclass is indented under subclass 124. Subject matter in which one of the short circuited elements is of the squirrel cage type.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 166+ for alternating current induction motors having squirrel cage type rotors.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 318+ for plural induction motor rotor members with a significant electric circuit which may include plural squirrel cage members; and subclasses 830+ for plural short circuited induction motor rotor members in an electric motor system controlled by movable motor structure.

This subclass is indented under subclass 114. Subject matter having plural armatures in a common field.

This subclass is indented under subclass 40. Subject matter having plural collectors for transferring the current between the rotor and a stationary part of the dynamoelectric device.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 495+ for miscellaneous electric motor systems having plural armature or rotor windings with means to control the current flowing therein.
323, Electricity: Power Supply or Regulation Systems, subclass 203 for dynamoelectric machine systems for controlling the voltage magnitude and plural sets of brushes.

This subclass is indented under subclass 127. Subject matter having both commutator and slip ring type collectors.

This subclass is indented under subclass 128. Subject matter adapted for use as a synchronous or rotary converter.

SEE OR SEARCH CLASS:
307, Electrical Transmission or Interconnection Systems, subclasses 45+, 82 and 151 for miscellaneous conversion systems having rotary converters.
318, Electricity: Motive Power Systems, subclass 719 for synchronous motor systems wherein the synchronous motors are self excited.
363, Electric Power Conversion Systems, subclasses 102+ and 174+ for rotary converter systems.

This subclass is indented under subclass 129. Subject matter adapted to be used for plural wire direct current systems.
(1) Note. This subclass relates, for example, to converters adapted to be used with the Edison three wire systems.

SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems, subclass 202 for balancer set systems.

This subclass is indented under subclass 128. Subject matter having plural separate armature circuits.

This subclass is indented under subclass 131. Subject matter having a polyphase armature winding.

This subclass is indented under subclass 128. Subject matter having an armature winding which is common to both the commutator and the slip ring collector.

This subclass is indented under subclass 133. Subject matter having plural field windings.

SEE OR SEARCH CLASS:
363, Electric Power Conversion Systems, subclass 104 for this subject matter in combination with a significant electric conversion circuit.

This subclass is indented under subclass 128. Subject matter having means to connect the field of the dynamoelectric device to the commutator collector.

This subclass is indented under subclass 127. Subject matter
having plural commutator type collectors.

This subclass is indented under subclass 136. Subject matter adapted to be used as double current direct current machines.

This subclass is indented under subclass 137. Subject matter in which one of the commutator type collectors is adapted to be used as an input and the other is adapted to be used as an output.
(1) Note. This subclass relates, for example, to the Dynamotor type machines.

This subclass is indented under subclass 137. Subject matter having hetro-axial excitation.
(1) Note. This subclass relates, for example, to double current direct current machines having cross field excitation.

This subclass is indented under subclass 136. Subject matter having plural armature windings.

This subclass is indented under subclass 140. Subject matter having plural field windings.

SEE OR SEARCH CLASS:
363, Electric Power Conversion Systems, subclass 104 for this subject matter in combination with a significant electric conversion circuit.

This subclass is indented under subclass 136. Subject matter having plural field windings.

SEE OR SEARCH CLASS:
363, Electric Power Conversion Systems, subclass 104 for this subject matter in combination with significant electric conversion circuit.

This subclass is indented under subclass 127. Subject matter having plural slip ring sets.

This subclass is indented under subclass 143. Subject matter having plural armature windings.

SEE OR SEARCH CLASS:
322, Electricity: Single Generator Systems, subclass 90 for this subject matter when utilized in a single generator system.

This subclass is indented under subclass 144. Subject matter having plural sets of poles.

This subclass is indented under subclass 144. Subject matter in which the armature windings are polyphase windings.

This subclass is indented under subclass 144. Subject matter in which the slip rings are connected in the field circuit.

This subclass is indented under subclass 127. Subject matter having plural sets of brushes.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 239+ and 248+, for brush holders or rigging and for brushes, per se.

SEE OR SEARCH CLASS:
322, Electricity: Single Generator Systems, subclass 53 for single generator systems wherein the generator has an odd number of brushes as, for example, third brush type generator.
323, Electricity: Power Supply or Regulation Systems, subclass 203 for dynamoelectric voltage magnitude machines having plural sets of brushes in combination with a significant electrical system.

This subclass is indented under subclass 148. Subject matter having plural field windings.

SEE OR SEARCH CLASS:
363, Electric Power Conversion Systems, subclass 104 for this subject matter in combination with a significant electric conversion circuit.

This subclass is indented under subclass 149. Subject matter having means for connecting the field windings in a polyphase manner.

This subclass is indented under subclass 148. Subject matter having means for connecting one brush to another brush by a direct connection having negligible impedance.

SEE OR SEARCH CLASS:
322, Electricity: Single Generator Systems, subclass 92 for this subject matter in a generating system.

This subclass is indented under subclass 40. Subject matter having a permanent magnet.

SEE OR SEARCH CLASS:
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclass 84, 92, 179, 205+, and 229+ for devices comprising at least one permanent magnet combined with an armature.

This subclass is indented under subclass 152. Subject matter in which the permanent magnet is combined with a flywheel.
(1) Note. This subclass relates, for example, to flywheel magneto machines.

SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, subclasses 572+ for
flywheels and rotors, per se.

This subclass is indented under subclass 152. Subject matter in which the permanent magnet is the stator of the dynamoelectric machine.

SEE OR SEARCH CLASS:
324, Electricity: Measuring and Testing, subclass 151 for galvanometers and other meters having similar structure.

This subclass is indented under subclass 154. Subject matter having means, in relation with the permanent magnet stator, to produce a variable reluctance so that the amount of magnetic flux traversing a certain part of the magnetic path varies.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 168+ for this subject matter in nonpermanent magnet alternating current generators.

This subclass is indented under subclass 152. Subject matter having a permanent magnet rotor.

SEE OR SEARCH CLASS:
324, Electricity: Measuring and Testing, subclass 146 for similar subject matter utilized in electric meters.

This subclass is indented under subclass 40. Subject matter
which is vertically disposed.

This subclass is indented under subclass 40. Subject matter relating to universal motors which will operate with either alternating current or direct current sources.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclass 245 and 246+ for universal motor systems.

This subclass is indented under subclass 40. Subject matter relating to alternating current rotary dynamoelectric devices.

This subclass is indented under subclass 159. Subject matter relating to frequency converters.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 127+ for this subject matter having plural collectors.

SEE OR SEARCH CLASS:
84, Music, subclasses 725+ for this subject matter in an electrical musical instrument, such as an electric organ.
191, Electricity: Transmission to Vehicles, subclass 7 for this subject matter in a distribution system utilized for transmitting electricity to a moving vehicle from a stationary point.
363, Electric Power Conversion Systems, subclasses 157+, especially subclasses 174+ for this subject matter in a conversion system.

This subclass is indented under subclass 159. Subject matter relating to dynamoelectric machinery for shifting the phase of the alternating current.

SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems, subclasses 201-204 for this subclass matter in a phase control system.

This subclass is indented under subclass 159. Subject matter relating to synchronous dynamoelectric machinery.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 700+ for this subject matter in a synchronous motor system.

This subclass is indented under subclass 162. Subject matter of the reaction type.

This subclass is indented under subclass 163. Subject matter having a toroidal coil.

This subclass is indented under subclass 162. Subject matter having an electromagnetic coil which is adapted to be energized by direct current.

This subclass is indented under subclass 159. Subject matter of the induction motor or induction generator type.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 727+ for induction motor systems.
322, Electricity: Single Generator Systems, subclass 47 for induction generator systems.

This subclass is indented under subclass 166. Subject matter having means to start a dynamoelectric machine, which is utilized as a motor, by the use of repulsion starting.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 725+ for repulsion motor systems; and subclass 728 for repulsion start induction motor systems.

This subclass is indented under subclass 166. Subject matter relating to inductor type generators wherein the magnetic circuit is varied by varying the reluctance of said magnetic circuit.

SEE OR SEARCH THIS CLASS, SUBCLASS:
155 for this subject matter having a permanent magnet in the magnetic circuit.

SEE OR SEARCH CLASS:
322, Electricity: Single Generator Systems, subclass 47 for induction type generator systems.

This subclass is indented under subclass 168. Subject matter relating to high frequency generators.
(1) Note. The high frequency is obtained, for example, by the use of saw tooth reluctance type rotor, which is rotated at a high rate of speed.

This subclass is indented under subclass 169. Subject matter relating to multi-frequency generators.

This subclass is indented under subclass 166. Subject matter relating to induction generators.
(1) Note. An induction generator is a synchronous motor which is either self excited by connecting a large condenser in its output circuit or by driving it above synchronous speed while connected to an energized circuit.

This subclass is indented under subclass 166. Subject matter relating to shifting field type induction motors.
(1) Note. This subclass relates, for example, to the shaded pole type of induction motor in which, although only a single phase of current is connected to the motor, a true rotating field is obtained by the use of pole faces which are partly free and partly surrounded by a short circuited coil.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclass 750 for reversing shaded pole induction motor systems; and subclasses 781+ for shaded pole induction motor systems.

This subclass is indented under subclass 159. Subject matter having a commutator.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 127+ for this subject matter having plural commutators.
167 for this subject matter in an induction motor.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 725+ for repulsion motor systems and subclasses 244+ for other alternating current motor systems in which the motor has a commutator.

This subclass is indented under subclass 173. Subject matter for use with a single phase of alternating current.

This subclass is indented under subclass 174. Subject matter in which the armature windings are conductively connected to the source of energy.

This subclass is indented under subclass 174. Subject matter in which the armature winding is connected to the source of energy by means of transformer action.

This subclass is indented under subclass 40. Subject matter relating to direct current dynamoelectric machines.

This subclass is indented under subclass 177. Subject matter relating to homopolar dynamoelectric machines.
(1) Note. A homopolar dynamoelectric machine is one in which the moving armature conductor is not in the form of a coil, but is rather in the form of one half of a single turn. Generally, this is achieved by utilizing a disk or a cylinder as the coil with pairs of brushes to conduct the current from and to the conductor at spaced points.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclass 253 for homopolar motor systems.
322, Electricity: Single Generator Systems, subclass 48 for this subject matter utilized in a generator system.

This subclass is indented under subclass 40. Subject matter relating to windings and core structure.

SEE OR SEARCH CLASS:
324, Electricity: Measuring and Testing, subclass 76.11 for the structure of integrating electric meters having a rotary portion which operates in the manner of an electric motor.
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclasses 220+ for the structure of electromagnets.
336, Inductor Devices, appropriate subclasses for the structure of inductor and inductive reactors.

This subclass is indented under subclass 179. Subject matter
relating to field or excitation windings or core structure.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 521+ for electric motor systems having means to control the field.

This subclass is indented under subclass 180. Subject matter having a combined permanent and electromagnet.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 152+ for permanent magnet machines.

SEE OR SEARCH CLASS:
322, Electricity: Single Generator Systems, subclass 46 for generator control systems in which the generator has a combined permanent and wound field structure.
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclasses 229+ for devices with electromagnets combined with permanent magnets having an armature.

This subclass is indented under subclass 180. Subject matter having a short circuited winding or conductor.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclasses 73+ for inductive devices having closed coils or single conductor members (e.g., rings, bands, discs, etc., of conductive material).

This subclass is indented under subclass 182. Subject matter having a damper type winding.
(1) Note. A damper winding is a winding which acts to absorb higher frequencies of magnetic flux by ohmic dissipation or by the generation of induced currents which oppose the higher frequencies of flux.

This subclass is indented under subclass 180. Subject matter having plural field windings.

SEE OR SEARCH CLASS:
322, Electricity: Single Generator Systems, subclasses 63+ for this subject matter in a single generator system.
363, Electric Power Conversion Systems, subclass 104 for this subject matter in combination with a significant electric conversion circuit.

This subclass is indented under subclass 184. Subject matter having plural sets of poles.

This subclass is indented under subclass 184. Subject matter in which one of the plural field windings is an interpole, compensating or neutralizing pole.

SEE OR SEARCH THIS CLASS, SUBCLASS:
185 for this subject matter when associated with plural independent sets of poles.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 521+ for this subject matter in an electric motor system.
322, Electricity: Single Generator Systems, subclasses 64-66 for this subject matter in a single generator system.

This subclass is indented under subclass 184. Subject matter having a slotted or divided pole.

SEE OR SEARCH THIS CLASS, SUBCLASS:
172 for split phase induction motors having a divided pole, one half of which is surrounded by a short circuiting conductor.
subclasses 182+ for field structure having short circuited windings or conductors, some of which are set into slots in the pole faces.

This subclass is indented under subclass 184. Subject matter relating to differentially related field windings.

This subclass is indented under subclass 180. Subject matter in which the field coil has a variable length or a tapped winding.

SEE OR SEARCH CLASS:
322, Electricity: Single Generator Systems, subclass 71 for this subject matter in a single generator system.
336, Inductor Devices, subclass 150 for inductor tap changing means.
388, Electricity: Motor Control Systems, subclasses 835+ for running-speed control systems in which the length of the field winding may be varied.

This subclass is indented under subclass 180. Subject matter having a magnetic shunt for shifting the field flux.

SEE OR SEARCH CLASS:
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclasses 220+ for miscellaneous magneto-mechanical devices which may utilize flux shunting means, see especially subclasses 236+.
336, Inductor Devices, subclass 133 and 160+ for inductive devices with adjustable magnetic shunts and inductive regulators with magnetic shunts, respectively.

This subclass is indented under subclass 180. Subject matter having adjustable magnetic structure.

SEE OR SEARCH THIS CLASS, SUBCLASS:
190 for the subject matter where the adjustable structure is a magnetic shunt.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 538+ for electric motor systems in which the motor structure is controlled or adjusted. Consult the search notes to these classes for related art.
322, Electricity: Single Generator Systems, subclasses 49+ for a single generator system in which the magnetic structure of a generator is controlled or adjusted.
336, Inductor Devices, subclasses 132+ for inductive devices having plural core parts which are relatively adjustable.

This subclass is indented under subclass 180. Subject matter having nonmagnetic inserts or air gaps in the field or winding structure.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclasses 135+, 165 and 178 for core structure with adjustable air gap, an air gap in the magnetic
shunt of an inductive regulator and inductive devices having closed cores with air gaps, respectively.

This subclass is indented under subclass 180. Subject matter having a nonuniform core cross section.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclasses 155+ for inductive regulators of the saturable type having nonuniform core cross sections, where a part of the core, having a small cross section, saturates before other parts of the core, having larger cross sections, saturate.

This subclass is indented under subclass 180. Subject matter relating to coil supports and spools.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclass 185 and 208 for coil supports for plural coil windings and coils on preformed supports or mounts (for single coil windings), respectively.

This subclass is indented under subclass 179. Subject matter relating to armature or primary windings or core structure.

SEE OR SEARCH CLASS:
324, Electricity: Measuring and Testing, subclasses 134+ for the structure of armatures utilized in integrating type electric meters.

This subclass is indented under subclass 195. Subject matter
relating to the prevention of corona discharges.

SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, subclasses 140+ for insulators having means to distribute a voltage stress along the insulator.
336, Inductor Devices, subclass 70 for coil capacitance modifying surge potential gradient modifying means.
361, Electricity: Electrical Systems and Devices, subclasses 212+ for the discharging of static electricity.

This subclass is indented under subclass 195. Subject matter having a short circuited winding or conductor.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 166+ for complete induction motors.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclasses 73+ for inductive devices having closed coils or single conductor members (e.g., rings, bands, discs, etc., of conductive material).

This subclass is indented under subclass 195. Subject matter having plural windings.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 495+ for this subject matter in an electric motor system.
322, Electricity: Single Generator Systems, subclass 90 for this subject matter in a single generator system.

This subclass is indented under subclass 198. Subject matter relating to combined stationary and rotary windings.

This subclass is indented under subclass 195. Subject matter having a variable length or a tapped winding.

SEE OR SEARCH CLASS:
322, Electricity: Single Generator Systems, subclass 93 for this subject matter in a single generator system.
336, Inductor Devices, subclasses 137+ for adjustable inductor having means to change the coil length or connections. Note especially indented subclass 150 for that subject matter having tap changing means. Also see subclass 15 for inductive devices with variable length coils, whose length varies through winding and/or unwinding of the coil.

This subclass is indented under subclass 195. Subject matter in which the winding conductors are in the form of bars.

This subclass is indented under subclass 195. Subject matter in which the winding conductors are in the form of open windings.
(1) Note. An open winding is a winding of the type in which, starting from a given point, it is not possible to reach that given point again by continuously going along the winding in only one direction.

This subclass is indented under subclass 195. Subject matter relating to closed windings.
(1) Note. A closed winding is a winding of such type that it is possible to arrive at any point by leaving that point and traversing the winding continuously in only one direction.

This subclass is indented under subclass 203. Subject matter relating to equalizers or equalizer windings.

This subclass is indented under subclass 203. Subject matter relating to multiplex windings.

This subclass is indented under subclass 203. Subject matter relating to lap windings.

This subclass is indented under subclass 203. Subject matter relating wave windings.

This subclass is indented under subclass 195. Subject matter relating to coils.

SEE OR SEARCH THIS CLASS, SUBCLASS:
194 for similar subject matter.

This subclass is indented under subclass 195. Subject matter relating to adjustable magnetic structure.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 538+ for the subject matter in electric motor systems.
322, Electricity: Single Generator Systems, subclasses 49+ for this subject matter in a single generator system.
336, Inductor Devices, subclasses 132+ for inductive devices having plural core parts which are relatively adjustable.

This subclass is indented under subclass 179. Subject matter relating to secondary windings or conductors.
(1) Note. A secondary winding or conductor is one in which current is induced by transformer action.

This subclass is indented under subclass 210. Subject matter relating to squirrel cage type secondary windings.

This subclass is indented under subclass 211. Subject matter having inherently variable impedance at variable frequencies.
(1) Note. This subclass relates, for example, to squirrel cage rotors in which the rotor bars are in the form of ribbons, set in deep slots so that the inductive reactance of the different portions of a ribbon are different. This subclass also relates, for example, to double squirrel cage type rotors.

This subclass is indented under subclass 179. Subject matter relating to antiparasitic conductors.
(1) Note. This subclass relates, for example, to the elimination of skin current effects in dynamoelectric machine windings; in which, due to the action of different inherent reactances in different parts of a common conductor the current is caused to concentrate in one part of the conductor with resulting excess heating. Such current concentration and excess heating can be avoided, for example, by dividing these conductors into a plurality of parallel members which are twisted about each other and insulated from each other everywhere except by their ends, where they are conductively joined.

SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, subclass 114 for split or imbricated conductors, per se.

This subclass is indented under subclass 179. Subject matter relating to coil retainers or slot closers.

SEE OR SEARCH CLASS:
428, Stock Material or Miscellaneous Articles, subclasses 544+ for stock materials, e.g., of indefinite length, which are all metal or have adjacent metal components.

This subclass is indented under subclass 179. Subject matter relating to slot liners.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclasses 196+ for inductor devices (e.g., transformers and inductive reactors) having supporting or spacing means between coil and core.

This subclass is indented under subclass 179. Subject matter relating to core features.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclasses 210-213, 216-219 and 233+ for various features of magnetic core structure in inductive devices, of which subclasses 233+ is the general subclass for cores not elsewhere classified.

This subclass is indented under subclass 216. Subject matter relating to means for securing laminae.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclass 210 for inductive devices with core clamps, wedges or fasteners for securing magnetic core lamination.

This subclass is indented under subclass 216. Subject matter relating to pole assembly and securing means.

This subclass is indented under subclass 40. Subject matter relating to current collectors.

SEE OR SEARCH CLASS:
191, Electricity: Transmission to Vehicles, subclasses 45+ for similar subject matter where current is collected from an extended conductor by a traveling brush.
318, Electricity: Motive Power Systems, subclasses 541+ for electric motor systems having current collector control means, such as brush shifting means.
322, Electricity: Single Generator Systems, subclass 53 and 54+ for single generator systems having brush control means for shifting the generator brush.
388, Electricity: Motor Control Systems, subclass 836 for running-speed control systems in which the position or number of brushes may be varied.
439, Electrical Connectors, subclasses 1+ for a pair of relatively movable electrical connectors.

This subclass is indented under subclass 219. Subject matter relating to the reduction of sparking at the current collector.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclass 439 for electric motor systems having means to control the commutation.

This subclass is indented under subclass 220. Subject matter having arc extinguishing means.
(1) Note. This subclass relates, for example, to dynamoelectric devices having means to extinguish arcs that result when the commutator flashes over.

SEE OR SEARCH CLASS:
361, Electricity: Electrical Systems and Devices, subclasses 1+ for safety and protection of systems and devices, indented subclasses 2+ for arc control, subclasses 20+ for generator protective circuits, and subclasses 23+ for motor protective circuits.

This subclass is indented under subclass 220. Subject matter for providing a spark neutralizing current.

This subclass is indented under subclass 220. Subject matter having flux compensating means.

This subclass is indented under subclass 223. Subject matter in which the flux compensating means is a compensating pole or winding.

This subclass is indented under subclass 223. Subject matter in which the flux compensating means is a short circuited coil circuit.

This subclass is indented under subclass 223. Subject matter in which the flux compensating means is a means to introduce a distortion of the magnetic field.

This subclass is indented under subclass 219. Subject matter having cooling means.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 52+ for rotary dynamoelectric machinery having cooling means for cooling more than the current collector per se.

This subclass is indented under subclass 219. Subject matter having cleaning, lubricating, resurfacing or repairing means as part thereof.

SEE OR SEARCH CLASS:
29, Metal Working, subclass 597 for miscellaneous methods of manufacturing and repairing commutators.

This subclass is indented under subclass 219. Subject matter having means to cause a brush to traverse along a path which is parallel to the axis of rotation of the dynamoelectric device.
(1) Note. The brush traverse may, for example, be an adjustment to regulate the position of the brush or it may be, for example, a means to cause the brush to traverse back and forth continuously so as to distribute wear.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 541+ for this subject matter in an electric motor system.

This subclass is indented under subclass 219. Subject matter having means for circumferentially shifting the position of the brush in order to effect reversal of the direction of rotation.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclass 292 for this subject matter in an electric motor system.
322, Electricity: Single Generator Systems, subclass 53 and 54+ for this subject matter in a single generator system.
323, Electricity: Power Supply or Regulation Systems, subclass 203 for this subject matter in a voltage magnitude
control system.

This subclass is indented under subclass 219. Subject matter relating to rotary structure.

SEE OR SEARCH CLASS:
428, Stock Material or Miscellaneous Articles, subclass 569 for stock materials or intermediate articles which comprise continuous interengaged phases of plural metals, at least one of which contains molybdenum or tungsten.

This subclass is indented under subclass 231. Subject matter relating to slip rings.

This subclass is indented under subclass 231. Subject matter relating to commutators.

SEE OR SEARCH CLASS:
29, Metal Working, subclass 507 for miscellaneous methods of manufacturing commutators.
174, Electricity: Conductors and Insulators, subclass 138 for commutator segment insulators, per se.
361, Electricity: Electrical Systems and Devices, subclasses 245+ for polarity reversing systems some of which have commutated type reversing switches.

This subclass is indented under subclass 233. Subject matter relating to winding connectors for connecting the winding to the commutator segments.

This subclass is indented under subclass 233. Subject matter relating to molded supports for supporting the commutator segments.

This subclass is indented under subclass 233. Subject matter relating to cylindrical or drum type commutators.

This subclass is indented under subclass 233. Subject matter relating to disk type commutators.

SEE OR SEARCH CLASS:
370, Multiplex Communications, subclasses 303+ for a multiplexing system having a rotary distributor.

This subclass is indented under subclass 219. Subject matter relating to fixed collector structure.

SEE OR SEARCH CLASS:
314, Electric Lamp and Discharge Devices: Consumable Electrodes, subclasses 130+ for electrode holders for arc lamps and similar devices.

This subclass is indented under subclass 238. Subject matter relating to brush holders or rigging.

This subclass is indented under subclass 239. Subject matter relating to means for lifting the brushes.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclass 728 for induction motor systems in which the induction motor starts as a repulsion motor.
322, Electricity: Single Generator Systems, subclasses 54+ for this subject matter in a single generator system.

This subclass is indented under subclass 239. Subject matter having means for circumferentially adjusting the position of the brushes.

This subclass is indented under subclass 239. Subject matter relating to means for holding or guiding the brushes.

This subclass is indented under subclass 239. Subject matter having means for operating the brush rigging or holders by means of fluid pressure.
(1) Note. This subclass relates, for example, to brush rigging in which the pressure of the brush against the commutator is determined by fluid pressure.

This subclass is indented under subclass 239. Subject matter in which the brush is affixed to a pivoted arm.

This subclass is indented under subclass 239. Subject matter in which the brush is slidably positioned in its holder.

This subclass is indented under subclass 245. Subject matter having an arm which presses against the brush to exert pressure between the brush and the commutator or slip ring.

This subclass is indented under subclass 245. Subject matter having an axial spring to press upon the brush so as to exert pressure between the brush and the commutator or slip ring.

This subclass is indented under subclass 238. Subject matter relating to brushes, per se.

SEE OR SEARCH CLASS:
373, Industrial Electric Heating Furnaces, appropriate subclasses for electric arc furnaces some of which utilize electrodes which are analogous to the brushes of this and indented subclasses.
313, Electric Lamp and Discharge Devices, subclasses 326+ (note particularly indented subclass 357) for electrodes for electric lamp and discharge devices, some of which are analogous to the brushes of this and the indented subclasses.
314, Electric Lamp and Discharge Devices: Consumable Electrodes, subclass 60 for arc lamp electrodes, some of
which are analogous to this and indented subclasses.

This subclass is indented under subclass 248. Subject matter having an electrical connector.
(1) Note. The electrical connector, for example, may be a copper pigtail which is integral with a carbon brush.

SEE OR SEARCH CLASS:
439, Electrical Connectors, appropriate subclasses for an electrical connector, generally.

This subclass is indented under subclass 250. Subject matter in which the structure is made of composite materials.

SEE OR SEARCH CLASS:
428, Stock Material or Miscellaneous Articles, subclasses 615+ for composite stock materials, such as, for example, plural metallic layers with interleaved nonmetallic layers.

This subclass is indented under subclass 248. Subject matter relating to the composition of the brush.
(1) Note. The search should, in all instances, continue in the class which relates to the composition, per se.

SEE OR SEARCH CLASS:
106, Compositions: Coating or Plastic, appropriate subclasses for coating or plastic compositions in general.
252, Compositions, subclasses 500+ for electrically conductive compositions and for brushes defined solely in terms of the composition of which they are composed.

This subclass is indented under subclass 252. Subject matter relating to carbonaceous compositions.

This subclass is indented under subclass 40. Subject matter relating to stator structure.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclasses 210-213, 216-219 and 233+ for various features of magnetic core structure of inductive devices, of which subclass 233 is the general subclass for inductor device cores not elsewhere classified.

This subclass is indented under subclass 254. Subject matter relating to railway type machines.

SEE OR SEARCH CLASS:
105, Railway Rolling Stock, subclasses 49+ for electric locomotives.

This subclass is indented under subclass 254. Subject matter relating to the prevention of flux loss due to stray fields.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclasses 84+ for inductor devices with electric and magnetic shielding means.

This subclass is indented under subclass 254. Subject matter relating to interfitting or claw tooth stators.

SEE OR SEARCH THIS CLASS, SUBCLASS:
263 for interfitting or claw tooth rotors.

This subclass is indented under subclass 254. Subject matter relating to stator structure of the frame and separate core type.

SEE OR SEARCH CLASS:
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclass 281 for electromagnets of the solenoid type having specific core structure of material and subclasses 297+ for core structure of electromagnets generally.
336, Inductor Devices, subclass 212, 216+ and 233+ for core structure or material of inductor generally.

This subclass is indented under subclass 258. Subject matter relating to core assembly.

This subclass is indented under subclass 258. Subject matter relating to end turn supports.

SEE OR SEARCH THIS CLASS, SUBCLASS:
270 for end turn supports for rotors.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclass 197 for inductor devices having coil clamps or wedges to secure or space coil and core.

This subclass is indented under subclass 40. Subject matter relating to rotor structure, per se.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclasses 210-213, 216-219 and 233+ for various features of magnetic core structure of inductive devices, of which subclass 233 in the general subclass for inductor device cores not elsewhere classified.

This subclass is indented under subclass 261. Subject matter relating to high speed rotors.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 168+ especially 169+, for induction type generators utilizing high speed rotors.

This subclass is indented under subclass 261. Subject matter relating to interfitting or claw tooth rotors.

SEE OR SEARCH THIS CLASS, SUBCLASS:
257 for interfitting or claw tooth stators.

This subclass is indented under subclass 261. Subject matter relating to armatures, per se.

This subclass is indented under subclass 264. Subject matter relating to drum type armatures.

This subclass is indented under subclass 264. Subject matter relating to hollow armatures.
(1) Note. This subclass relates, for example, to armatures having a double air gap.

This subclass is indented under subclass 264. Subject matter relating to ring type armatures.

This subclass is indented under subclass 264. Subject matter relating to disc type armatures.

This subclass is indented under subclass 264. Subject matter relating to salient pole armatures.

This subclass is indented under subclass 261. Subject matter relating to end turn supports.

SEE OR SEARCH THIS CLASS, SUBCLASS:
260 for end turn supports for stator windings.

SEE OR SEARCH CLASS:
336, Inductor Devices, subclass 197 for inductor devices having coil clamps or wedges to secure or space core and coil.

This subclass is indented under subclass 261. Subject matter relating to banding.

SEE OR SEARCH THIS CLASS, SUBCLASS:
262 for high speed type rotors.

This subclass is indented under subclass 40. Subject matter relating to elements.

SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, subclasses 567-617 for mechanical elements, per se.

This subclass is indented under subclass 40. Subject matter relating to miscellaneous features not set forth in the indented subclasses under subclass 40.

NONDYNAMOELECTRIC:
This subclass is indented under the class definition. Subject matter which is not related to the conversion of energy between the electrical and mechanical state by electromagnetic action.
(1) Note. Consult the classes referred to in the search notes to the class definition of this class for other classes having similar subject matter.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 10+ for subject matter under the class definition related to the conversion of energy between the electrical and the mechanical state by means of electromagnetic action.

SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, subclasses 116+ for the subject matter of this subclass in combination with an electrical system.
322, Electricity: Single Generator Systems, subclass 2 for subject matter of this subclass in an electric generator system.

Nuclear reaction:
This subclass is indented under subclass 300. Subject matter relating to the obtaining of energy in the electrical state from the internal energy of the atom.
(1) Note. This subclass relates, for example, to electric generators consisting of radioactive sources which acquire a charge due to the emission of electrons or other ionized particles at such a high speed as to go through a considerable adverse electric gradient before being collected.

SEE OR SEARCH CLASS:
331, Oscillators, subclass 94 for electrical oscillators of the molecular or particle resonant type (e.g., Maser).
376, Induced Nuclear Reactions: Processes, Systems, and Elements, subclasses 100+ for fusion reactors; and subclasses 347+ for fission reactors.

Contact potential difference:
This subclass is indented under subclass 301. Subject matter comprising at least a pair of metal electrodes having dissimilar work functions and a material (e.g., gas) ionized by a radioactive source, the electrodes and the material so arranged relative to each other that the ions of the
material, under the influence of the field established between the electrodes are collected by the electrodes to provide a source of current for an external load.

P-N semiconductor:
This subclass is indented under subclass 301. Subject matter comprising two intimately united semiconductor materials, one of the N type and one of the P type, and a radioactive source which irradiates the semiconductor materials to liberate charge carriers (electrons and holes) therein which flow under the influence of the field across the junction of the semiconductor materials to be collected on opposite sides of the junction and thus, provide a source of current for an external load.

Secondary electron emission:
This subclass is indented under subclass 301. Subject matter wherein energy from a radioactive source is directed toward a material which emits electrons in response thereto, the emitted electrons being collected by an electrode and providing a source of current and potential for an external load between the electrode and the radioactive source and/or the electron emissive material.

Direct charged particle emission:
This subclass is indented under subclass 301. Subject matter comprising a radioactive source of charged particles and electrode means (cathode and/or anode) to collect the charged particles to provide a source of current and potential for an external load between the electrodes or electrode and source.

Thermal or pyromagnetic:
This subclass is indented under subclass 300. Subject matter in which the energy is changed between the electrical and the thermal state.
(1) Note. This subclass relates, for example, to means for generating electricity due to a change in the temperature of material, or to means for generating mechanical energy due to the change of magnetic flux which results from change of temperature.
(2) Note. The combination of an electrical generator system and a nuclear reactor is provided for in Class 376, Induced Nuclear Reactions: Processes, Systems, and Elements, subclasses 317+.

SEE OR SEARCH CLASS:
136, Batteries: Thermoelectric and Photoelectric, subclasses 200+ for thermocouple batteries, per se.
318, Electricity: Motive Power Systems, subclass 117 for thermoelectric motor systems, per se.
322, Electricity: Single Generator Systems, subclass 2 for electrical generator systems in which electricity is converted to heat which in turn is converted into electricity.
374, Thermal Measuring and Testing, subclass 176 for a thermometer having a ferromagnetic sensor.
376, Induced Nuclear Reactions: Processes, Systems, and Elements, subclasses 317+ for electrical generator systems in which the products of an induced nuclear reaction are converted to electricity.

With heat actuated bimetal element:
This subclass is indented under subclass 306. Subject matter having structure comprised of at least two materials having different coefficients of expansion which structure is deformed by the energy in its thermal state, and during its deformation, does mechanical work.

Charge accumulating:
This subclass is indented under subclass 300. Subject matter in which the electrical energy results from the incremental buildup of the potential charge over a period of operation of the device.

Electrostatic:
This subclass is indented under subclass 308. Subject matter in which the electrical charge or potential is of static electricity.
(1) Note. This subclass relates, for example, to static electric generators, commonly known as Whinhurst machines.

Friction:
This subclass is indented under subclass 309. Subject matter in which the static electricity is generated by frictional moving contact of two parts of the apparatus.

SEE OR SEARCH CLASS:
361, Electricity: Electrical Systems and Devices, subclass 207 for electrostatic electric relay systems such as those which utilize the Winslow effect, which is defined in the definition of that subclass.

Piezoelectric elements and devices:
This subclass is indented under subclass 300. Subject matter which includes a shaped body of a material which exhibits an electrostatic polarization when subjected to mechanical stress or which exhibits a mechanical stress tending to produce deflection, expansion, or contraction when subjected to electrical stress, the body being so shaped relative to the electromechanical properties of the material as to render the body useful for the conversion of energy between the electrical and mechanical states, and combinations of such bodies with means which utilize or which contribute to the utilization of such bodies for the conversion of energy between the electrical and mechanical states.
(1) Note. In the titles and definitions of the subclasses indented hereunder, the term "piezoelectric element" is used to denote the shaped body, per se, and the term "piezoelectric device" is used to denote the combination of such a shaped body and means which utilizes or which contributes to the utilization of such bodies for the conversion of energy between the electrical and mechanical states.
(2) Note. This and the indented subclasses include
piezoelectric materials in combination with electrodes for the piezoelectric materials, such devices in combination with ancillary devices (such as holders or ovens) and piezoelectric motors or generators. Piezoelectric crystals in combination with an art device are classified with the art device.
(3) Note. This and the indented subclasses include patents relating to methods for using piezoelectric devices where such methods are not otherwise classified. Such methods are classified in the subclass providing for the apparatus required to perform the method.
(4) Note. Neither this nor the indented subclasses include mere piezoelectric materials, nor the method of or apparatus for making piezoelectric materials or piezoelectric devices. For the excluded subject matter, see the search notes below. Piezoelectric materials per se, when shaped to claimed configurations, where the configuration is disclosed as being significant to the piezoelectric property of the crystal (e.g., plate, AT cut) are classified in indented subclasses 357+.

SEE OR SEARCH THIS CLASS, SUBCLASS:
26 for magnetostrictive transducers which may have similar circuitry or structure as that used with piezoelectric devices.

SEE OR SEARCH CLASS:
29, Metal Working, subclass 25.35 for methods of making piezoelectric devices.
73, Measuring and Testing, subclass 170.08 and 170.09 for fluid flow direction measuring utilizing a piezoelectric sensor and subclass 170.33 for a piezoelectric probe for oceanos:graphic measuring.
178, Telegraphy, subclass 70 and 71.11 for repeaters which use piezoelectric elements.
235, Registers, subclass 924 for registers which use a ferroelectric element.
250, Radiant Energy, subclass 370 and 492 for a radiant energy source which may be combined with a piezoelectric element.
252, Compositions, subclass 62.9 and the classes specified in the notes thereto, for piezoelectric compositions.
307, Electrical Transmission or Interconnection Systems, subclass 400.
313, Electric Lamp and Discharge Devices, subclass 508 for the combination of a piezoelectric element and a luminescent
solid or liquid.
318, Electricity: Motive Power Systems, subclass 118 for magnetostrictive motor systems which may be similar to piezoelectric motor systems.
322, Electricity: Single Generator Systems, subclass 2 for the miscellaneous generator systems having a nonmagnetic generator (other than a piezoelectric generator).
324, Electricity: Measuring and Testing, subclass 727 for processes and means for subjecting a piezoelectric element to an electric test, as for the purpose of predicting its frequency drift, or determining the polarity of charge produced by mechanical stress, or of determining its activity. Search subclasses 76.39+ for frequency meters, per se. Search subclass 109 for electricity sensing, measuring, or testing using a piezoelectric element.
330, Amplifiers, subclass 5.5 for parametric amplifiers which may use piezoelectric material.
359, Optics: Systems (Including Communication) and Elements, subclasses 230+ for light control by a piezoelectric opaque element.
361, Electricity: Electrical Systems and Devices, subclasses 271+ for capacitors, per se, which may be similar in material or structure to a piezoelectric element.
363, Electric Power Conversion Systems, appropriate subclasses for such systems which utilize piezoelectric devices.
365, Static Information Storage and Retrieval, subclass 145 for ferroelectric storage systems. Note the polarization of the ferroelectric element is usually changed as a function of the stored information.
374, Thermal Measuring and Testing, subclasses 117+ for temperature measuring using a vibratory effect.
427, Coating Processes, subclass 100 for piezoelectric materials produced by coating methods.

Adding or subtracting mass:
This subclass is indented under subclass 311. Subject matter combined with a means for changing the mass of the piezoelectric element, e.g., depositing mass onto or evaporating mass from the surface of a piezoelectric element to change its resonant frequency.
(1) Note. Other methods of changing the mass include grinding, cutting, or chemical etching.

SEE OR SEARCH CLASS:
29, Metal Working, subclass 25.35 where the changing of the mass may be a step in the manufacture of a piezoelectric device.

Surface acoustic wave devices:
This subclass is indented under subclass 311. Subject matter wherein a piezoelectric element is combined with, or comprises, a material or body having an elastic surface on which varying mechanical stresses produced by the piezoelectric element travel.

SEE OR SEARCH THIS CLASS, SUBCLASS:
334 for piezoelectric generators of acoustic waves which travel through a body or material rather than on the surface of the body or material, e.g., "bulk mode".

SEE OR SEARCH CLASS:
235, Registers, subclass 181 and 197 for devices wherein the surface wave device functions as a correlator or convolver.
333, Wave Transmission Lines and Networks, subclasses 157+ for devices wherein the waveguide serves as a delay line, and subclasses 187+ where the surface wave device performs as an electric filter.

Electrical systems:
This subclass is indented under subclass 311. Subject matter for supplying electric energy via an electric circuit element to piezoelectric devices and/or electric circuit elements which are supplied with electric energy by piezoelectric devices.
(1) Note. The circuit element is other than just an electrode of the piezoelectric device.

SEE OR SEARCH CLASS:
73, Measuring and Testing, subclasses 67+ for piezoelectric transducers which couple an alternating current, electric circuit, and a device having mechanical vibrations for
testing purposes and for the testing system which utilizes such transducers.
181, Acoustics, subclasses 101+ for acoustic wave (especially seismic) which may utilize a piezoelectric element.
307, Electrical Transmission or Interconnection Systems, subclass 400 for electrical systems utilizing electrets.
318, Electricity: Motive Power Systems, subclass 116 for electric motor control systems where the electric motor is of the piezoelectric type. Note that subclass 314 of this class (310) also contains some systems where electric potential is applied to a piezoelectric device.
322, Electricity: Single Generator Systems, subclass 2 for the miscellaneous generator systems having a nonmagnetic generator (other than a piezoelectric generator).
324, Electricity: Measuring and Testing, subclass 727 for processes of and means for subjecting a piezoelectric crystal to an electric test, as for the purpose of predicting its frequency drift, or of determining the polarity of charge produced by mechanical stress, or of determining its activity. Search subclasses 76.39+ for frequency meters, per se.
330, Amplifiers, subclass 5.5 for solid element wave propagating amplifiers wherein the solid element may be of the piezoelectric phonon type, and subclass 174 for amplifiers having electromechanical transducers, which may be piezoelectric crystals, in a signal coupling circuit.
333, Wave Transmission Lines and Networks, subclass 149 for delay networks utilizing piezoelectric devices, and subclasses 187+ for filters utilizing piezoelectric devices.
361, Electricity: Electrical Systems and Devices, subclass 211 for electric circuits for relays which may be piezoelectric.
363, Electric Power Conversion Systems, appropriate subclasses for such systems utilizing piezoelectric devices.
367, Communications, Electrical: Acoustic Wave Systems and Devices, subclasses 140+ for piezoelectric transducers used in electrical acoustic wave communication.
369, Dynamic Information Storage or Retrieval, subclass 144 for a piezoelectric phonograph pickup.
600, Surgery, subclasses 437+ for ultrasonic systems which may include a piezoelectric element.
601, Surgery: Kinesitherapy, subclasses 15+ and 46+ for ultrasonic systems which may include a piezoelectric
element.

Temperature compensation circuits:
This subclass is indented under subclass 314. Subject matter having circuit elements associated with the piezoelectric element which compensate for changes in its piezoelectric properties upon changes in temperature, e.g., turnover point, impedance, frequency, resistance, etc.

SEE OR SEARCH CLASS:
331, Oscillators, subclass 116 for electromechanical resonator controlled oscillators which may compensate via electric circuit elements for changes in the resonator frequency due to the temperature change.

Input circuit for simultaneous electrical and mechanical output from piezoelectric element:
This subclass is indented under subclass 314. Subject matter wherein (a) electrical energy is supplied to the piezoelectric element and (b) the piezoelectric element has an electrical output and a mechanical output both of which are utilized.
(1) Note. Subject matter of this subclass type may include feedback circuits.
(2) Note. A device such as a nondestructive testing unit which is electrically excited to produce an acoustic wave output and then receives the returning acoustic wave and converts that into an electric output is viewed as having sequential rather than simultaneous outputs for classification purposes under subclass 314. Thus, such a device which includes electric-circuit elements for both input and output would usually be classified in subclasses 317 or 319 rather than in this subclass.

SEE OR SEARCH THIS CLASS, SUBCLASS:
318 for the combination of an electric circuit element and an electrical resonator comprised of a piezoelectric device which converts an alternating electrical input voltage to mechanical motion which is entirely converted by the piezoelectric device itself back to an alternating electrical output voltage having the same frequency as, and in phase with the input voltage.
321 for such piezoelectric devices, per se, which include some structure other than the piezoelectric element itself to mechanically establish the resonant frequency of the device.
326 for such piezoelectric devices wherein the resonant frequency is established by mechanically damping undesired frequencies.
subclasses 348+ for such piezoelectric devices, per se, in which the piezoelectric element itself determines the resonant frequency.

Traveling wave motor:
This subclass is indented under subclass 316.01. Subject matter wherein two or more groups or piezoelectric elements lying along a driving surface expand and contract in repetitive cycles generating a mechanical output having a crest or high point which appears to move along the surface of the piezoelectric elements along a direction of travel (typically rotary or linearly) whereby a driven surface pressed resiently against the driving surface is carried along the direction of the crest or high point.

Charging and discharging:
This subclass is indented under subclass 316.01. Subject matter having specific circuitry (e.g., capacitor, coil, combination etc.) either (a) to source electrons flowing to the piezoelectric element, or (b) to sink electrons flowing from the piezoelectric element.

SEE OR SEARCH CLASS:
361, Electricity: Electrical Systems and Devices, subclasses 225+ for the step of merely charging or polarizing piezoelectric material.

Input circuit for mechanical output from piezoelectric element:
This subclass is indented under subclass 314. Subject matter having electric circuit elements for driving the
piezoelectric element for the purpose of producing a usable mechanical output therefrom.

SEE OR SEARCH THIS CLASS, SUBCLASS:
316 for similar subject matter having, in addition, an electrical output which is fed back to the input.

Input circuit for electrical output from piezoelectric element:
This subclass is indented under subclass 314. Subject matter having electric circuit elements for driving the piezoelectric element for producing an electrical output from the piezoelectric element.
(1) Note. The output may be fed back to the input circuitry or to additional circuitry. Examples of devices in this subclass are circuits in which the piezoelectric element behaves or functions as an electric circuit element rather than being utilized for any mechanical output, e.g., oscillators, resonators.

SEE OR SEARCH THIS CLASS, SUBCLASS:
316 for similar subject matter having, in addition a utilizable mechanical output.

SEE OR SEARCH CLASS:
329, Demodulators, particularly subclass 328 for a demodulator including a piezoelectric element.
331, Oscillators, subclass 73 for electron coupled oscillators employing piezoelectric crystals, subclass 116 for transistor oscillators employing an electromechanical resonator which may be of the piezoelectric type, subclass 139 for crystal bridge type oscillators, subclass 155 for oscillators utilizing a piezoelectric crystal to couple an electromechanical oscillator frequency determining resonator to the oscillator system, and subclasses 158+ for piezoelectric crystal type oscillator systems in general.
332, Modulators, especially subclasses 139+ for piezoelectric elements used in frequency modulators.
368, Horology: Time Measuring Systems or Devices, subclasses 155+ for electric oscillators used in clocks which may utilize a piezoelectric element.

Electrical output circuit:
This subclass is indented under subclass 314. Subject matter having an electric circuit element which receives the electric output from the piezoelectric element.
(1) Note. This subclass is generally restricted to devices that have a mechanical input to the piezoelectric device. However, an exception is where an electric input to a piezoelectric device is acknowledged as prior art or merely nominally disclosed (e.g., as by schematically representing an A.C. or D.C. source as the input), or where the piezoelectric device functions as both an electromechanical transducer and a mechanical to electrical transducer and the electric input circuit is acknowledged as prior art or merely nominally disclosed (the output circuit may be to "protect" the input circuit from the voltage produced by the mechanical-electrical function).

Piezoelectric slab having different resonant frequencies at different areas:
This subclass is indented under subclass 311. Subject matter wherein a unit of piezoelectric material is disclosed as having a resonant region and at least one other region that has a deliberately different resonant frequency from the first resonant region, e.g., energy trapped, dot resonator, or monolithic filter devices.
(1) Note. Devices which use the energy trapping concept are specifically included since the regions in which the energy is trapped (usually under electrodes) must be different from that of the surrounding region (usually not electrodes). Thus, even if the device has only one resonator, it has two regions with different resonant frequencies. The same reasons apply to monolithic filters.
(2) Note. Typical ways of providing different resonant frequencies on the same slab of piezoelectric material are loading portions of the material, or removing portions of the material, or providing changes in the cross section of the slab.

SEE OR SEARCH THIS CLASS, SUBCLASS:
322 for acoustic wave generators which may utilize a wedge or other shape element which has different resonant frequencies in different areas.

SEE OR SEARCH CLASS:
333, Wave Transmission Lines and Networks, subclasses 187+
for electric filters that may utilize such a piezoelectric slab.

Combined with resonant structure:
This subclass is indented under subclass 311. Subject matter wherein the piezoelectric element is combined with structure whose natural frequency of vibration is disclosed as being the same as the operating frequency of vibration of the piezoelectric element.
(1) Note. "Resonant structure" is intended to be structure other than a mere support for a piezoelectric resonator.
(2) Note. Examples of devices found in this subclass would be composite resonators (e.g., tuning forks or electric filters) comprised of piezoelectric elements mounted on structure which together have a resonant frequency within the operating frequency of the device, the piezoelectric element(s) being either input and/or output transducers for the device.

SEE OR SEARCH THIS CLASS, SUBCLASS:
345 and 348, for mounting devices for piezoelectric elements that may resonate.

SEE OR SEARCH CLASS:
84, Music, subclass 409 for tuning forks.
178, Telegraphy, subclass 70 for tuning forks.
333, Wave Transmission Lines and Networks, subclasses 187+ for piezoelectric wave filters (combination of piezoelectric element and resonator).
368, Horology: Time Measuring Systems or Devices, subclasses 155+ for resonant vibrators.

Acoustic wave type generator or receiver:
This subclass is indented under subclass 321. Subject matter wherein the mechanical energy applied to or produced by the resonant structure is disclosed as being caused by or producing traveling compressions in an elastic material.
(1) Note. The combination of a piezoelectric element and a cavity resonator is included in this subclass even though the
wave is a "standing wave" rather than a traveling wave.
(2) Note. Since devices which produce or receive acoustic waves can sometimes be structurally similar to mechanically coupled devices, the search notes for subclasses 323 and 328 should be consulted.

SEE OR SEARCH THIS CLASS, SUBCLASS:
334 and 335, for acoustic wave devices that don't necessarily use a resonant structure.

SEE OR SEARCH CLASS:
47, Plant Husbandry, Digest 12 for ultrasonic generators which may utilize a piezoelectric element.
68, Textiles: Fluid Treating Apparatus, subclass 3 for use of supersonic energy in washing machines.
73, Measuring and Testing, subclasses 67+ and 522 for piezoelectric transducers which couple an alternating current, electric circuit and a device having mechanical vibrations for testing purposes.
99, Foods and Beverages: Apparatus, subclass 451 and Digest 12 for use of supersonic energy in food processing.
116, Signals and Indicators, subclasses 137+, Digests 18 and 19 for acoustic wave signaling devices, e.g., noise makers.
134, Cleaning and Liquid Contact With Solids, subclass 1 and 17 for processes of cleaning or fluid treatment of solids which may include the application of ultrasonic energy.
166, Wells, subclass 177 and 249 for processes and apparatus to apply acoustic or vibrational energy to the material surrounding a well bore.
181, Acoustics, subclass .5, 106, 108, 113, 139, and 142 for acoustic wave generators and detectors.
200, Electricity: Circuit Makers and Breakers, subclass 61.01 and Digest 20 for acoustically actuated switches.
210, Liquid Purification or Separation, subclass 738 for processes or apparatus involving coagulation by ultrasonic vibrations, and subclass 542 for apparatus for coagulating suspensions utilizing piezoelectric means.
340, Communications: Electrical, subclass 870.30 for piezoelectric transmitters, and subclasses 384.1+ for electrically driven noise makers.
366, Agitating, subclass 127 for apparatus for agitating which utilize piezoelectric means.
367, Communications, Electrical: Acoustic Wave Systems and Devices, subclasses 140+ for piezoelectric transducers used in electrical acoustic wave communication; and subclasses 197+ for sound responsive selective devices.
422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing, subclass 20 and 127+ for process and apparatus using acoustic wave generating means.
600, Surgery, subclasses 437+ for systems using acoustic or vibratory energy for medical treatment or diagnosis.
601, Surgery: Kinesitherapy, subclasses 46+ for systems using acoustic or vibratory energy for medical treatment or diagnosis.

Direct mechanical coupling:
This subclass is indented under subclass 321. Subject matter in which the resonant structure physically contacts a body on which it performs work, or from which it receives energy.
(1) Note. Examples of subject matter in this subclass include ultrasonic tools, vibrators and atomizers.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 328+ for devices which may be similar, but don't operate at resonance.

SEE OR SEARCH CLASS:
30, Cutlery, subclass 45 for a vibratory cutting device which may be driven by a piezoelectric element.
74, Machine Element or Mechanism, subclass 1 for supersonic tools which may be driven at resonance by a piezoelectric element. Note that this class contains mechanical amplitude transformers, per se.
228, Metal Fusion Bonding, subclass 1.1, 110.1+ and 262 for ultrasonic welders which may use a piezoelectric element.
366, Agitating, subclass 127 for agitators or vibrators which may be driven by a piezoelectric element.
408, Cutting by Use of Rotating Axially Moving Tool, subclass 700 for ultrasonic cutters which may be driven by a piezoelectric element.
433, Dentistry, subclass 86 and 119 for ultrasonic dental tools driven by a piezoelectric element.
451, Abrading, subclass 165 and 910 for ultrasonic abrading.
601, Surgery: Kinesitherapy, subclasses 46+ for vibrators which may be driven by a piezoelectric element.

Motor producing continual motion:
This subclass is indented under subclass 323.01. Subject matter wherein the piezoelectric element expands and contract cyclically and repeatedly to produce motion of an armature or rotor along a single direction.
(1) Note. Motion can be linear or rotary.

Traveling wave motor:
This subclass is indented under subclass 323.02. Subject matter wherein two or more groups or piezoelectric elements lying along a driving surface expand and contract in repetitive cycles generating a mechanical output having a crest or high point which appears to move along the surface of the piezoelectric elements along a direction of travel (typically rotary or linearly) whereby a driven surface pressed resiently against the driving surface is carried along the direction of the crest or high point.

Stator:
This subclass is indented under subclass 323.03. Subject matter wherein significance is attributed to either (a) the structure which generates the traveling wave or (b) means for bearing the weight of the structure which generates the traveling wave.

Support:
This subclass is indented under subclass 323.04. Subject
matter having a specific mounting apparatus (attachment device) to hold the stator.

SEE OR SEARCH THIS CLASS, SUBCLASS:
345 and subclass 348, for mounting devices for piezoelectric elements that may resonate.

Piezoelectric element or electrode:
This subclass is indented under subclass 323.04. Subject matter having a specific detail of either (a) the piezoelectric element (e.g., geometry, shape, placement etc.) or (b) an electric conductor for connecting the piezoelectric element to a source of current.

SEE OR SEARCH THIS CLASS, SUBCLASS:
323.11 for specific material or composition of the piezoelement in a vibration wave or traveling wave motor.

Oval track:
This subclass is indented under subclass 323.04. Subject matter wherein either the stator or the driving surface has a closed loop shape with at least one set of parallel straight portions.

Armature:
This subclass is indented under subclass 323.03. Subject matter having a specific detail directed to the driven member of the motor such as shape, geometry or structure.

Pressing means detail:
This subclass is indented under subclass 323.08. Subject matter wherein significance is attributed to resilient means used for pushing the driven member against the driving surface such as shape, type, or orientation.

Specific material or composition:
This subclass is indented under subclass 323.03. Subject matter wherein wherein significance is attributed to a specific substance or compound used to construct the traveling wave motor.

SEE OR SEARCH CLASS:
252, Compositions, subclass 62.9 for compositions specialized and designed for use as piezoelectric materials and processes of making said compositions.

Langevin or pencil type motor:
This subclass is indented under subclass 323.02. Subject matter wherein an ultrasonic motor comprises either (a) a stator having of a longitudinal-torsional composite resonator or (b) a stack of piezoelectric elements stacked longitudinally in a direction along the length of a generally long cylinderical shaped armature.

Output member detail:
This subclass is indented under subclass 323.12. Subject matter wherein the motor armature is provided with specific means to facilitate coupling to a driven body.

Roller or ball elements:
This subclass is indented under subclass 323.13. Subject matter wherein the output member has a structure employing either cylindrical or spherical shaped members.

Material or material property:
This subclass is indented under subclass 323.13. Subject
matter wherein wherein significance is attributed to a specific substance or has a specific characteristic.

Elliptical motion at fixed point (i.e., walking) or Ratchet and Pawl motor:
This subclass is indented under subclass 323.02. Subject matter having either (a) an actuator with a fixed base and two or more piezoelectric elements each causing the actuator to move in a direction, the combined motion of the two or more piezoelectric elements causes the actuator to orbit, whereby repetitive orbits of the actuator pushes the driven member along a direction of travel or (b) a rotor or a driven member is constrained by a hinged or pivoted device adapted to fit into a notch or sloping tooth of a bar or wheel to permit motion in one direction only.

Positions an object:
This subclass is indented under subclass 323.01. Subject matter a piezoelectric element expands or contracts to locate or adjust a member into a desired location.

SEE OR SEARCH CLASS:
347, Incremental Printing of Symbolic Information, subclass 68, and 70 for a piezoelectric element which contracts to deform a vibration plate attached directly to the piezoelectric element to expel ink droplets.

Device performs work on an object (e.g., welding, cutting):
This subclass is indented under subclass 323.01. Subject matter wherein the piezoelectric element applies an oscillating force to a body for moving the body a distance.

Horn or transmission line:
This subclass is indented under subclass 323.01. Subject matter wherein either (a) the piezoelectric element is used as a transducer to convert electric energy into sound energy
or (b) the piezoelectric element is combined with specific means to conduct sound energy.

SEE OR SEARCH CLASS:
333, Wave Transmission Lines and Networks, subclasses 187+ for piezoelectric wave filters (combination of piezoelectric element and resonator).

Detector (e.g. sensor):
This subclass is indented under subclass 323.01. Subject matter wherein the piezoelectric element has a characteristic which changes in response to a change in a physical parameter or condition, and assessment is made of the physical parameter or condition.

SEE OR SEARCH CLASS:
73, Measuring and Testing, subclass 35.11 for a piezoelectric vibration sensor, for detecting engine knock. Subclasses 290, 721, 727, 763+, and 861.18+ for various force or pressure measuring and indicating devices or systems which may utilize a piezoelectric transducing element. Subclasses 763+ for strain sensors which may use a piezoelectric element, subclasses 861.18 for flow meters which may use a piezoelectric element, subclass 290 for depth or liquid level gases which may utilize a piezoelectric element, and Digest 4 for various piezoelectric measuring and testing devices.

Diaphragm:
This subclass is indented under subclass 321. Subject matter in which the resonant structure is a diaphragm mechanically associated with the piezoelectric element, the combination being resonant at the operating frequency of the piezoelectric element.

SEE OR SEARCH THIS CLASS, SUBCLASS:
328 for the combination of a diaphragm driven by a piezoelectric element which diaphragm is not resonant with respect to the operating frequency at the element.

SEE OR SEARCH CLASS:
181, Acoustics, subclasses 148+ for acoustical devices which use diaphragms.
340, Communications: Electrical, subclass 338 for a noise generator which may include a piezoelectric element mounted on a diaphragm.

Sandwich or langevin type:
This subclass is indented under subclass 321. Subject matter in which the piezoelectric element or elements are coupled to a front and/or rear mass, which combined structure is disclosed as being resonant at the operating wavelength.
(1) Note. Devices of this subclass type may consist of, for example, a piezoelectric element connected to the wall of a cleaning tank, the combined structure being resonant at the operating wavelength or a piezoelectric element connected to a mechanical amplifier (horn) and a tool, the combined structure being resonant at the operating wavelength. Devices of this subclass type may be referred to as the Boldine type.

SEE OR SEARCH CLASS:
366, Agitating, Cross-Reference Art Collection, 600 for similar resonant structures.

Combined with damping structure:
This subclass is indented under subclass 311. Subject matter having the piezoelectric element combined with structure designed to absorb, or attenuate undesired energy emanated from or applied to the element.
(1) Note. Subject matter under subclass type does not include structure which merely mounts a piezoelectric resonator.

SEE OR SEARCH CLASS:
181, Acoustics, appropriate subclasses for various specific acoustic wave attenuators or modifiers.

On back of piezoelectric element:
This subclass is indented under subclass 326. Subject matter in which an absorber or attenuator is in intimate contact
with a first part of the surface of the piezoelectric element to remove mechanical energy therefrom while mechanical energy is allowed to emanate from or into another part of the surface not in the same plane with the first part.

SEE OR SEARCH THIS CLASS, SUBCLASS:
335 for piezoelectric devices which eliminate back waves by reflecting them to recombine them either constructively with the front wave, or destructively with the back wave.

SEE OR SEARCH CLASS:
73, Measuring and Testing, subclasses 67+ for nondestructive testing apparatus which may use a piezoelectric element with an attenuating element on a surface.

With mechanical energy coupling means:
This subclass is indented under subclass 311. Subject matter having means to apply mechanical energy from an external source to the piezoelectric element to mechanically stress the element, or means to apply mechanical energy produced by the element to an external load.
(1) Note. The means of this subclass type are other than those whose only proximate function is to contribute to the proper operation of the piezoelectric element itself such as by supporting, housing, prestressing, or damping the element. The means of this subclass type may, however, perform such contributory functions in addition to its energy transferring function. In such cases, the means may be considered as having two coequal proximate functions, i.e., a contributory function and a transferring function, the transferring function being the basis for classification in this subclass. Whether or not such means renders a recited combination classifiable in this subclass may depend on the disclosed intended use of the means. For example, if a piezoelectric element is recited in combination with a housing, the proximate function of the housing may be assumed to be contributory, i.e., to contribute to the proper operation of the piezoelectric element by protecting it from its environment, which is insufficient basis for placement in this subclass. However, it may be disclosed that the housing is additionally intended to transfer mechanical energy from the piezoelectric element to a load external to the housing (e.g., air, as in the case of certain acoustic transducers) in which case the combination is classifiable here.
(2) Note. The coupling means of this subclass type is not necessarily limited to motion transmitting members such as mechanical linkages, diaphragms, etc., but may include
reaction members which cooperate with the piezoelectric element to render the element itself capable of directly applying its mechanical energy to a load or receiving mechanical energy from source. Such means may, for example, be recited as a "support" which in addition to merely fixing the element in a particular location relative to the support itself, is disclosed as a means against which forces produced by the element may react in order that the element may do work on an external load. In this case, the "support" is considered as having two proximate functions {see (1) Note above}, i.e., to fixedly locate the element with respect to the support itself and to render the combination capable of applying the mechanical energy of the element to an external load.
(3) Note. Refer to the SEARCH CLASS notes of subclass 323 for the loci of similar art which may contain a piezoelectric device (which may or may not be resonant).

SEE OR SEARCH THIS CLASS, SUBCLASS:
323 and 325, for similar devices which may be designed to be resonant at the driving frequency.

SEE OR SEARCH CLASS:
73, Measuring and Testing, subclasses 763+ for strain sensors which may use a piezoelectric element, subclasses 861.18 for flow meters which may use a piezoelectric element, subclass 290 for depth or liquid level gases which may utilize a piezoelectric element, and Digest 4 for various piezoelectric measuring and testing devices.
84, Music, subclasses 730+ for electric tone generators or pickups combined with a musical device, wherein said generator or pickup could utilize a piezoelectric element, and Digest 24 for various piezoelectric devices mechanically coupled to a musical instrument.
137, Fluid Handling, subclass 827, 828 and 831 for fluid control devices (e.g., fluid amplifier) which may be combined with a piezoelectric element.
181, Acoustics, subclass .5 for seismic vibration detectors which may use a piezoelectric element.
200, Electricity: Circuit Makers and Breakers, subclass 181 for switching which may utilize a piezoelectric element.
366, Agitating, subclass 127 for an agitating apparatus utilizing a piezoelectric actuating means.
369, Dynamic Information Storage or Retrieval, subclasses 128+ for electromechanical storage or retrieval; and subclass 144 for piezoelectric phonograph pickups.
417, Pumps, subclass 322 for pumps which may use a
piezoelectric element.

Including inertia type operator:
This subclass is indented under subclass 328. Subject matter wherein the coupling means includes a massive body which is mechanically connected to a part of the peripheral surface of the piezoelectric element and which is movable relative to another part of the peripheral surface of the element in at least one direction so that when an accelerating force is applied to the combination in the one direction, the resulting acceleration of the massive body causes the part of the peripheral surface to which it is connected to move relative to the other part of the peripheral surface to thus stress the element between the two parts of its peripheral surface.
(1) Note. This subclass relates, for example, to acceleration or velocity sensing elements, per se.

SEE OR SEARCH CLASS:
73, Measuring and Testing, subclass 71 for vibration sensing apparatus utilizing an inertia element, and subclasses 516+ for inertia-type accelerometers.
102, Ammunition and Explosive Devices, subclass 210 and Digest 5 for inertia operated ignites.
367, Communications, Electrical: Acoustic Wave Systems and Devices, subclass 158 for inertia operated piezoelectric transducers for use in underwater electrical acoustic wave communications.

Bending type:
This subclass is indented under subclass 328. Subject matter wherein the mechanical stresses applied to or produced within the piezoelectric element include a coplanar pair of oppositely directed moments of mechanical force.

Plural elements:
This subclass is indented under subclass 330. Subject matter having two or more piezoelectric elements and wherein bending
type mechanical stresses are produced in at least one of the elements.

Multimorph:
This subclass is indented under subclass 331. Subject matter having at least two piezoelectric elements so joined and oriented that one expands while the other contracts to produce a bending type mechanical stress in the composite structure.
(1) Note. The elements of the multimorphs of this subclass type may be in direct physical contact with each other or may be separated by a spacing means or "center vane".

SEE OR SEARCH CLASS:
369, Dynamic Information Storage or Retrieval, subclass 144 for the structure of piezoelectric phonograph pickup s which utilize multimorphic elements.

Shear or torsional type:
This subclass is indented under subclass 328. Subject matter wherein the mechanical stresses applied to or produced within the piezoelectric element include a pair of noncolinear, oppositely directly linear forces, or a pair of oppositely directed moments of mechanical force acting in parallel planes.

Acoustic wave type generator or receiver:
This subclass is indented under subclass 328. Subject matter wherein the mechanical energy applied to or produced by the piezoelectric element is disclosed as being caused by or producing traveling compressions in an elastic material.
(1) Note. See the SEARCH CLASS notes of subclass 322 above, for the loci of similar art which may contain a piezoelectric device (which may or may not be resonant).

SEE OR SEARCH THIS CLASS, SUBCLASS:
322 for acoustic generators and receivers using a resonant structure.

SEE OR SEARCH CLASS:
333, Wave Transmission Lines and Networks, subclass 149 and 187+ for electric delay lines or filter networks having, as a part thereof, means for coupling vibrational energy between a piezoelectric crystal and a mechanical delay line or filter.

With lens or reflector:
This subclass is indented under subclass 334. Subject matter combined with means to change the direction of a ray of the acoustic wave energy.

SEE OR SEARCH CLASS:
181, Acoustics subclasses 175+ for acoustic transducers combined with a sound modifier.
367, Communications, Electrical: Acoustic Wave Systems and Devices, subclass 150 and 151 for acoustic transducers combined with a lens or reflector, respectively.

Nondestructive testing type:
This subclass is indented under subclass 334. Subject matter disclosed as being used in the determination of physical characteristics of a body or material by producing acoustic wave energy to be applied to the body or material and/or by being mechanically stressed by acoustic wave energy received from the body or material.

SEE OR SEARCH CLASS:
73, Measuring and Testing, subclasses 67+ for systems which utilize the above transducers.

Underwater type:
This subclass is indented under subclass 334. Subject matter wherein the piezoelectric element is enclosed in a submergible watertight housing, which housing provides for the transmission of acoustic energy between the element and the water in which the housing is submerged.

SEE OR SEARCH CLASS:
367, Communications, Electrical: Acoustic Wave Systems and Devices, subclasses 141+ for similar underwater piezoelectric transducers.

Force or pressure measuring type:
This subclass is indented under subclass 328. Subject matter wherein the electrical output of the piezoelectric element is disclosed as being used to indicate the magnitude of the mechanical force or forces stressing the element.

SEE OR SEARCH CLASS:
73, Measuring and Testing, subclass 290, 721, 727, 763+, and 861.18+ for various force or pressure measuring and indicating devices or systems which may utilize a piezoelectric transducing element.
600, Surgery, subclasses 481+ for a cardiovascular pressure transducer which may utilize a piezoelectric transducing element.

Voltage, spark or current generator:
This subclass is indented under subclass 328. Subject matter wherein mechanical energy from an external source is applied to the piezoelectric element to produce an electric potential difference between at least two electrically accessible points on the surface of the element.

SEE OR SEARCH CLASS:
84, Music, Digest 24 for piezoelectric signal generators stimulated by a musical instrument.
102, Ammunition and Explosive Devices, subclass 18, 210 and Digest 5 for voltage generators which may include a piezoelectric element.
123, Internal-Combustion Engines, subclass 148 for a piezoelectric spark generator.
200, Electricity: Circuit Makers and Breakers, subclass 61.01 and Digest 20 for sound or vibration devices which produce a signal and may include a piezoelectric element.
315, Electric Lamp and Discharge Devices: Systems, subclass
55 and 209 for piezoelectric element spark generators.
340, Communications: Electrical, subclass 365 for pressure sensitive keyboards which generate an electric signal and may use a piezoelectric element.
361, Electricity: Electrical Systems and Devices, subclasses 247+ and particularly subclass 260 for piezoelectric ignites.
431, Combustion, subclass 43, 128, 132, 254+, 258+, and Digests 58, 60 and 63 for electric ignites which may utilize a piezoelectric element.

Encapsulated or coated:
This subclass is indented under subclass 311. Subject matter having a protective means in direct, intimate contact with all surfaces of the piezoelectric element.

SEE OR SEARCH CLASS:
156, Adhesive Bonding and Miscellaneous Chemical Manufacture, appropriate subclasses for laminating methods including adding a moisture proof layer to an object.
264, Plastic and Nonmetallic Article Shaping or Treating: Processes, subclass 272 for electrical component encapsulating.
427, Coating Processes, appropriate subclasses for moisture proofing by coating.
428, Stock Material or Miscellaneous Articles, appropriate subclasses for a stock material product in the form of a single or plural layer web or sheet, including a waterproof component, note especially subclass 321 and 351 (in which the web or sheet is structurally defined or has a structurally defined element or component), and subclasses 411+ for a nonstructural laminate defined merely by the composition of the layers.

With temperature modifier and/or gas or vapor atmosphere control:
This subclass is indented under subclass 311. Subject matter having means to maintain or change the temperature of the piezoelectric element, or having means to control or confine gas or vapor around the element.
(1) Note. Subject matter of this subclass type includes, for example, heat sinks, heat shields, fans, and cooling fluid.

SEE OR SEARCH THIS CLASS, SUBCLASS:
346 for a piezoelectric element combined with structure whose properties compensate for undesired changes in the device which would result from temperature change.

SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, appropriate subclasses for housing and envelopes having means for conducting electricity between the inside and outside of the housing or envelope, including such devices as are used for piezoelectric elements. See subclass 9 for those involving the use of a vacuum, subclass 14 for those having fluid conditioning or maintenance means, subclasses 15.1+ for those having temperature modifying means, subclasses 17.05+ and 50.5+ for hermetically sealed envelopes, and subclasses 50+ for miscellaneous boxes and housings.
219, Electric Heating, subclasses 19+ for electric heating apparatus, per se, designed to produce a constant temperature.
220, Receptacles, appropriate subclasses for the structure of housings, casings, and envelopes, per se. Note particularly subclass 2.1 where the housing, casing, or envelope is of the electric discharge tube or similar (such as piezoelectric crystal) type.
331, Oscillators, subclass 69 for oscillators with outer casing or housing provided with means to modify the temperature therein and wherein the oscillator may utilize a piezoelectric crystal element, and subclass 70 for oscillators which may utilize a piezoelectric crystal element with means to modify the crystal temperature.

For plural piezoelectric elements:
This subclass is indented under subclass 341. Subject matter which includes more than one piezoelectric element.

With heating element:
This subclass is indented under subclass 341. Subject matter
having means to add heat to the piezoelectric element, which means is a heat producing element (e.g., resistive heater within the crystal housing or directly in contact with the crystal).

SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, subclasses 15+ for enclosures for circuit elements which may include a heater.
219, Electric Heating, subclass 210 for the combination of a piezoelectric element and a heating device.
236, Automatic Temperature and Humidity Regulation, subclass 1 for temperature control devices which may include, or protect a piezoelectric element.
331, Oscillators, subclass 69 and 70 for oscillators with outer casing or housing provided with means to modify the temperature therein, which oscillator may utilize a piezoelectric element.

Sealed unit:
This subclass is indented under subclass 341. Subject matter including an airtight housing around the crystal element.

SEE OR SEARCH THIS CLASS, SUBCLASS:
343 for sealed enclosures which are heated.

SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, subclasses 8+, 17.05+ and 50.5+ for hermetically sealed housings combined with an electric circuit element which may be a piezoelectric element.

Supported by elastic material:
This subclass is indented under subclass 311. Subject matter wherein the only member (other than a lead wire for electrical connection to the electrodes) physically contacting the piezoelectric element is comprised of rubber, bulk fiber (e.g., glass wool), foam rubber, or other elastomer.

With temperature compensating structure:
This subclass is indented under subclass 311. Subject matter having structure whose properties compensate for undesired changes in the device which would result from temperature change.
(1) Note. Undesired changes of this subclass type cause, for example, force to be applied to the crystal as a result of expansion or contraction of the crystal or structurally associated member due to temperature variation. Structure of this subclass type may have, for example, matching or mismatching coefficients of thermal expansion. Devices that merely modify the temperature, or keep the temperature around the crystal unchanged (e.g., heat sinks, fans, ovens, etc.), however, are provided for elsewhere. See the search notes below.

SEE OR SEARCH THIS CLASS, SUBCLASS:
341 for the combination of a piezoelectric element and a temperature modifying means.

Compensated air gap:
This subclass is indented under subclass 346. Subject matter wherein the device includes at least one electrode for the piezoelectric element which is spaced from the piezoelectric element to form an air gap, and the temperature compensating structure either keeps the air gap constant for changes in temperature, or else purposely varies the air gap so that the piezoelectric element's output remains constant for changes in temperature.

With mounting or support means:
This subclass is indented under subclass 311. Subject matter having means to spatially position the piezoelectric element relative to some reference structure or reference point.
(1) Note. This subclass and those indented hereunder include, for example, means for mounting piezoelectric elements that function merely as resonators, filters, or other circuit element types of devices, i.e., an electrical-to-mechanical-back-to-electrical type of transducer. The devices may be viewed as "passive" in that
they don't perform mechanical work on something, or receive mechanical energy from something.

Air gap:
This subclass is indented under subclass 348. Subject matter wherein the device includes at least one electrode for the piezoelectric element which is spaced from the piezoelectric element or contacts the piezoelectric element without being mechanically attached to it, i.e., the electrode merely lays on the piezoelectric element, or the piezoelectric element merely rests on the electrode.

SEE OR SEARCH THIS CLASS, SUBCLASS:
347 for air gap type devices which include a means to compensate for the effects temperature change could have on the device due to change in the air gap.

Adjustable:
This subclass is indented under subclass 349. Subject matter having means to adjust the position of the electrode.

SEE OR SEARCH THIS CLASS, SUBCLASS:
354 for similar adjustable mounting structure but which clamps the piezoelectric element.

Suspended by thin member:
This subclass is indented under subclass 348. Subject matter in which each member that physically contacts the piezoelectric element is relatively long and thin (e.g., rod, wire, spring, thread, string, etc.), and supports the piezoelectric element in the direction of its (the member's) long dimension.
(1) Note. If the thin rod member also exerts a significant clamping pressure on the piezoelectric element, the device is classified under subclasses 354+ below.

Point contact on major surface only:
This subclass is indented under subclass 351. Subject matter wherein the suspension member contacts the piezoelectric element only on a major surface or surfaces, and the area of contact is small relative to the total area of the major surface.

Contact at edges only:
This subclass is indented under subclass 351. Subject matter wherein each suspension member contacts the piezoelectric element only at an edge or edges of the element.

Clamped:
This subclass is indented under subclass 348. Subject matter wherein the mounting means exerts a compressive stress on the piezoelectric element to secure it to a base or support and not merely for the purpose of preloading an element.

SEE OR SEARCH THIS CLASS, SUBCLASS:
350 for adjustable mounting structure which does not actually clamp the piezoelectric element.

Spring bias:
This subclass is indented under subclass 354. Subject matter in which the clamping force is the result of a resilient member (e.g., a spring).

90 degrees to major surface and margin clamped only:
This subclass is indented under subclass 355. Subject matter wherein the clamping force is applied in a direction perpendicular to the major surfaces, and the crystal surface is in physical contact with its support structure only along the outer, peripheral edge of the major surfaces or portion thereof.

Orientation of piezoelectric polarization:
This subclass is indented under subclass 311. Piezoelectric noncrystalline materials and elements in which the direction of polarization is significant with respect to the piezoelectric property of the material and/or in adopting the element to its intended function.
(1) Note. This subclass may contain methods of polarizing materials, per se, wherein such polarizing produces a piezoelectrically active element.
(2) Note. This subclass includes noncrystalline piezoids such as amorphous quartz, or quartz crystals in a binder which may then have various axis aligned.

SEE OR SEARCH CLASS:
29, Metal Working, subclass 25.35 for methods of making piezoelectric devices which may include the step of polarizing.
252, Compositions, subclass 62.9 and the classes specified in the notes thereto for piezoelectric compositions.
361, Electricity: Electrical Systems and Devices, subclass 233 for methods of treating articles with electric energy which may include polarizing.
427, Coating Processes, subclasses 457+ and 472 for polarization or oriented vapor deposition of a possibly piezoelectric element.

Ceramic composition (e.g., BaTiO[subscrpt]3[end subscrpt]):
This subclass is indented under subclass 357. Subject matter in which the piezoelectric material is comprised of an oriented (polarized) solid polycrystalline aggregate material, e.g., BaTiO[subscrpt]3[end subscrpt].

SEE OR SEARCH CLASS:
106, Compositions: Coating or Plastic, subclass 391.5 for ceramic compositions in general.

More than one poling direction (e.g., rosen transformer):
This subclass is indented under subclass 358. Subject matter wherein a piezoelectric element is polarized in a curvilinear or more than one linear direction.
(1) Note. This subclass may include memory devices wherein the polarization direction is changed to represent a stored bit of information.

SEE OR SEARCH CLASS:
340, Communications: Electrical, subclass 173.2 for ferroelectric storage systems.

Rotation of crystal axis (e.g., cut angle):
This subclass is indented under subclass 311. Subject matter comprising piezoelectric crystalline materials and elements wherein the orientation of the crystallos:graphic axis with respect to the piezoelectric property of the materials is recited and significant in adapting the element to its intended function.

Quartz:
This subclass is indented under subclass 360. Subject matter in which the piezoelectric material is crystalline silicon dioxide.

Rochelle salt:
This subclass is indented under subclass 360. Subject matter in which the piezoelectric material is potassium sodium tartrate.

Electrode materials:
This subclass is indented under subclass 311. Subject matter having electrodes attached to the piezoelectric element
wherein the composition of the electrode is uniquely selected to enhance either the performance of the element/electrode combination or facilitate its manufacture.
(1) Note. Subject matter of this subclass type includes, for example, materials selected because they easily adhere to a piezoelectric material and materials that don't effect the piezoelectric's characteristics, etc.

Multilayer:
This subclass is indented under subclass 363. Subject matter wherein the electrode is made up of two or more layers of materials.
(1) Note. Subject matter of this subclass type may include, for example, a material directly adhered to the piezoelectric element chosen for its bonding ability, then covered with a layer of a material which may have superior conductivity, followed by a layer that resists oxidation, etc.

Electrode arrangement:
This subclass is indented under subclass 311. Subject matter involving the position of the electrodes with respect to the piezoelectric material, including electrode size, shape, and placement.
(1) Note. This subclass relates, for example, to piezoelectric elements having coated electrodes, electrodes cemented on or otherwise attached, and the structure of the electrode or its position with respect to the piezoelectric material or another electrode.

SEE OR SEARCH CLASS:
228, Metal Fusion Bonding, appropriate subclasses, especially subclasses 120-124.7 and 903 for a process of bonding a metallic part to a nonmetallic part.
403, Joints and Connections, appropriate subclasses for joints of general utility.

More than two:
This subclass is indented under subclass 365. Subject matter where the device has three or more separate electrodes.
(1) Note. The electrodes may be spaced about in a single surface of the piezoelectric material, or may be on two or more different surfaces or one of the three or more electrodes may be interposed between two layers of piezoelectric material so as to form a "sandwich".

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 331+ where the element has combined therewith means to transmit to or receive from the element mechanical force.

SEE OR SEARCH CLASS:
331, Oscillators, subclass 163 for crystal oscillator systems with a piezoelectric crystal having three or more electrodes in circuit.

Piezoelectric element shape:
This subclass is indented under subclass 311. Subject matter comprising piezoelectric materials and elements wherein the shape, proportions, or dimensions of the element or material is significant.
(1) Note. "Element" for the purpose of this subclass includes any structure consisting essentially of a plurality of pieces of piezoelectric material intimately joined together to form a composite structure.

SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 357+ where the specific polarization direction is significant with respect to the piezoelectric property.
subclasses 360+ where the specific orientation of the crystal axis of the material is significant with respect to the piezoelectric property.

Rectangular plate:
This subclass is indented under subclass 367. Subject matter wherein the shape of the piezoelectric element is essentially that of a solid rectangle, i.e., having three pairs of parallel sides.
(1) Note. Subject matter of this subclass type may include, for example, a cube.
(2) Note. Slight deviations from the exact shape specified above will not operate to exclude the device from this subclass if the overall appearance of the element remains rectangular, i.e., one or more pairs of sides may not be exactly parallel, one or more surfaces may be grooved or machined, edges may be rounded, or holes may be in or pass through the device.

Circular disc, ring, or cylinder:
This subclass is indented under subclass 367. Subject matter wherein the overall shape of the piezoelectric element is essentially that of a right solid cylinder.
(1) Note. Subject matter of this subclass type may include, for example, hollow cylindrical piezoelectric elements, split-ring or C-shaped elements and such elements having machined or textured surfaces if the overall shape is essentially as described above.

"U" or "tuning fork" shape:
This subclass is indented under subclass 367. Subject matter wherein the piezoelectric element is, or includes a portion shaped essentially like the letter "U" or "Y" or the letter "V" with a stem attached to the base (thus resembling a tuning fork).
(1) Note. This subclass is intended to include elements that may consist of a plurality of the above shapes, e.g., H-shaped elements and W-shaped elements.

Sphere or hemisphere:
This subclass is indented under subclass 367. Subject matter wherein the shape of the piezoelectric element is such that
its outer surface can be essentially generated by the revolution of a circle about one of its diameters or by one half of such a generated surface.
(1) Note. Subject matter of this subclass type may specifically include, for example, hollow spherical or hemispherical piezoelectric elements.
(2) Note. Slight deviations from the exact shape defined above will not exclude a piezoelectric element from this subclass if the overall shape of the element is spherical or hemispherical.

The following subclasses are collections of published disclosure pertaining to various aspects of the electrical generator or motor art which aspects do not form an appropriate base for subclass classification in the classification schedule.
(1) Note. Disclosures are placed herein for value as a search aid and in no instance do they represent the entire extent of the prior art.

PIEZOELECTRIC POLYMERS (E.G., MYLAR, PVDF):
Polymeric materials which are disclosed as being either inherently piezoelectric or have been treated (e.g., via polarizing) to give them usable piezoelectric properties (for example, PVDF, Mylar, frozen rubber, PVC, etc.).
(1) Note. This cross reference art collection is intended as an aid to the searcher for locating these materials and the structure they are associated with.