Class Definition for Class 91 - MOTORS: EXPANSIBLE CHAMBER TYPE

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CLASS 91,	MOTORS: EXPANSIBLE CHAMBER TYPE
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SECTION I - CLASS DEFINITION

This class is limited to motors for converting the energy of a pressure fluid into mechanical work in which a charge of simple pressure fluid is admitted to an expansible chamber, the expansion of said chamber converting into work only the original energy of the charge, the charge after expansion of said chamber being exhausted to some place other than whence it came, and in which no energy is extracted from the charge except by expansion of the chamber, said motors when of the reciprocating or oscillating type including control of the fluid.

(1) Note. Claims Not Controlling in Patents Prior to 1936. Patents issued prior to 1936 have not necessarily been classified by claims so that the placement of these patents does not necessarily indicate lines of classification. However, most of the patents regardless of their age have been placed in accordance with their claimed subject matter. PLACEMENT OF PATENTS A. Involving Combination and Subcombination Subclasses: In many instances the schedule of this class provides for a combination which requires a given subcombination, and elsewhere below provides for the subcombination. The following rule has been followed as to the placement of the original patent, and as to cross-referencing, and should be followed in the future. Where the combination subclass requires the same subcombination as is provided for in the subcombination subclass, i.e., subcombination defined with the same specificity in both subclasses, a patent disclosing the combination is placed as an original in, or under, the combination subclass regardless of whether the claims are directed to the combination or subcombination and is not cross-referenced to the subcombination subclass. A patent disclosing only the subcombination and claiming same is placed as an original in the subcombination subclass and is not cross-referenced to the combination subclass. This rule is applicable only in instances where there is but a single subcombination subclass, i.e., no indented subclasses, but the combination subclass may be further subdivided into indented subclasses. The prime feature of this situation is that the subcombination must, by definition, be of equal specificity in the two subclasses. A search for the subcombination, at least in the case where it is adapted to be used in the combination, of necessity involves all of the patents in the combination subclass. Under this system of placing the patents a complete search of the combination can be made in the combination subclass, and of the subcombination in both subclasses without the addition to the search files of the otherwise necessary cross-reference copies. The subclasses involved in this combination-subcombination relationship have been indicated in the schedule by numbers in parenthesis, as explained in a paragraph after the class title. Exemplary of this situation in the indented subclasses (223-229) provide for a distributor (valve) in the piston of a cyclically operable motor combination while subclass 422 requires only a valved piston subcombination. As between these subclasses any patent having a disclosed cyclically operable motor is placed as an original in subclass 222 or one of the indented subclasses regardless of whether the means which makes the motor cyclically operable is claimed and is not cross-referenced in subclass 422. A complete search for the subject matter provided for in subclass 422 of necessity involves all of the patents in subclasses 222-229. B. Involving Ancillary or Auxiliary Expansible Chamber Motor: In many instances the claimed motor which provides the basis of classification for a patent in Class 91 is provided with another expansible chamber motor which merely performs an ancillary or auxiliary function for the main motor. Illustrative of such functions are motor valve or lock, or lubricator actuation. In such cases the structure or operation of the ancillary motor does not constitute a basis for original classification of the patent in the Class 91 schedule unless the patent includes a claim to the auxiliary motor, per se. However, the patent may be cross-referenced on the basis of the auxiliary motor. For example, see subclasses 6-33 and 282-283. Subclasses 6-33 provide for fluid supply through diverse paths to a single expansible chamber. In this case the chamber must be a chamber of the motor which causes the patent to be classified in Class 91. Subclasses 282-283 provide for the same type of supply to a motor chamber, but in this case the motor is an auxiliary motor in that it actuates the distributor of another motor. This type of control of a distributor motor does not cause classification of the patent as an original in subclasses 6-33, but cross-reference to subclasses 6-33 is appropriate.

SECTION II - LINES WITH OTHER CLASSES AND WITHIN THIS CLASS

Combinations With Load Devices.

Inasmuch as the basic purpose of a motor is to operate a load the inclusion of the load in the claim by name only or in general terms will not exclude a patent from this class. An exception to this general rule exists where the load on the motor is a valve. The combination of an expansible chamber motor and a valve as the load driven thereby, even if the valve is claimed by name only, is excluded from this class and will be found in Class 137, Fluid Handling, or Class 251, Valves and Valve Actuation. A second exception exists where the claimed nominal load on the motor is an expansible chamber means solely disclosed as the master of a pulsator. This combination is classifiable in Class 60, subclasses 533-594.

This line also applies where the load is a tool; that is, a named tool driven by the motor will not exclude a patent from this class if no tool details are recited. However, if a support for the work being acted upon by the tool is claimed, classification in the appropriate tool class results even though both the tool and the support are claimed by name only. Also see the Search Class 173 note in section III below for the line with regard to a nominally claimed tool driven by an expansible chamber motor combined with other features such as work cleansing or tool feeding.

No attempt has been made to review the classification of all patents found in classes relating to loads adapted to be driven by a motor. Thus, it is to be noted that the original classification of all patents is not consistent with the above statement as to nominally claimed loads and this particularly applies as to classes not recently reclassified. In those instances in which a body of art is known to exist in a given class, in which the load on the motor is claimed only nominally, and especially where the classification of that class provides for a fluid motor actuator for the device, currently issuing patents will not be classified as originals in Class 91 even though the load is only nominally claimed.

The means which transmits power from the working member of the motor to the load to be driven, e.g., linkage, gearing, etc., is not considered to be the load for the motor. See the Search Class 74 note in the class definition of Class 91 for a further discussion of this subject.

RELATIONSHIP TO CLASS 92 Class 92 is directed to expansible chamber devices, per se, and is related to Class 91 as a subcombination thereof. Class 92 is limited to expansible chamber devices in which the working member has an oscillating or reciprocating motion to expand and contract the expansible chamber. Thus, Class 92 cannot take the subcombination of any Class 91 motor in which the working member is of the rotating type as defined in subclass 58 of Class 91. With respect to expansible chamber motors in which the working member has a reciprocating or oscillating motion to expand and contract the expansible chamber, Class 92 will take those patents in which no control of the motive fluid by a valving action is claimed. Thus, any claimed valving of motive fluid of an expansible chamber motor in sufficient to preclude classification is Class 92 even though the valving claimed may not be all of the valving necessary to cause the motor to operate in the intended manner. However, if a claim is for an expansible chamber motor driving a specifically claimed Class 92 device, then classification is in Class 92 regardless of the details of the expansible chamber motor recited. See Class 92, subclass 3. For the classification of various subcombination features of Class 92 devices elsewhere classified see the class definition and appropriate notes in Class 92. With regard to claim interpretation to determine whether valving is claimed to cause classification in Class 91, or is not claimed thus permitting classification in Class 92 the following criteria have been followed: 1. Claims which include a limitation such as "means for supplying fluid to the motor" or "means supplying fluid to the motor" are construed as requiring no more than the conduits or ports which supply the fluid and would, therefore, not be interpreted as including valving for Class 91. 2. Claims which include a limitation similar to that in (1) above, but with a further limitation which indicates a change in supply of working fluid such as--alternately, periodically, intermittently, pulsing, fluctuating, reversing flow, etc.--are construed as necessarily including more than a mere conduit or port and are excluded from Class 92. These patents would thus be classified on their claimed disclosure of what performs the noted change in the supply. Thus, a patent claiming "means (for) alternately supplying motive fluid to the motor" would be classified in Class 91 if said means is disclosed as a valve. 3. A port in an expansible chamber wall which is disclosed as controlled by the working member as, for example, an exhaust port which is overrun by a piston, together with the working member constitutes valving for Class 91. If such a port is claimed classification is in Class 91 regardless of whether the claim sets forth that the working member controls the port. RELATIONSHIP TO CLASS 60 The general line between Class 91 and Class 60 is that if subject matter relating to power production comprising more than an expansible chamber motor or more than a plurality of such motors is claimed, classification is in Class 60 if otherwise appropriate. More specifically the line may be categorized as follows: A. Plural or combined type motors (1) The combination of a motor classifiable, per se, in Class 91 with a motor of another type (including a pulsator) i.e., one which, per se, would be classified in another motor class, is classified in Class 60. See Class 60 subclasses 698-720. However, the combination of a Class 91 type motor with a second motor which performs an ancillary function only of the Class 91 type motor, e.g., valve operating motor, etc. and provides no power for external use is not excluded from Class 91 even if the second motor is of another type (e.g., electric motor). (2) The combination of a plurality of Class 91 type motors or a Class 91 type motor having a plurality of working members, e.g., pistons, etc., is classified in Class 91. See the Search Class 60 note in subclass 170 of Class 91 for a further statement of this line. B. Motive fluid source, modification or exhaust treatment (1) Pumps. The inclusion in a claim of a pump broadly which provides motive fluid for utilization by the Class 91 motor does not preclude classification in Class 91. The following examples of terminology have been considered to be nominal inclusion of a pump and if so claimed would not preclude classification in Class 91: (a) a pump; (b) a rotary pump; (c) a motor driven pump; (d) a motor driven rotary pump; (e) an internal combustion engine having an intake manifold (as a source of vacuum); (f) a plurality of pumps arranged in parallel; (g) a circuit comprising a sump, pump and motor. The following examples have been considered to be significant inclusion of a pump, and if so claimed would preclude classification in Class 91 and cause classification in Class 60, if otherwise appropriate: (a) a pump which is characterized as to type, e.g., centrifugal, eduction, constant displacement, variable displacement, pulsator, etc., (however, see (b) in the preceding paragraph); (b) a motor driven pump in which the motor is characterized as to type, e.g., turbine, electric motor, internal combustion engine, etc. (however, see (e) in the preceding paragraph); (c) a pump which has any detail thereof recited as, for example, a "piston"; (d) a plurality of pumps in series; (e) a particular physical relation between a nominal pump, and (1) a motor supplied thereby, or (2) with a sump, reservoir or tank forming part of the circuit supplying the pump. For example, this particular physical relation may include their relation in space or mechanical interconnection means. See particularly Class 60 subclasses 325-494. (2) Accumulators. A motor having an expansible chamber in constant communication with an accumulator for pressurized motive fluid is not precluded from Class 91 regardless of the specificity with which the accumulator is recited, the accumulator in this case being considered to be merely a part of the expansible chamber. Class 60 takes an accumulator combined with a Class 91 motor in which a control valve means is interposed between the accumulator and expansible chamber unless the accumulator is claimed so broadly as to amount to a mere conduit. See particularly Class 60, subclasses 325-494. (3) Internal Generation. Class 60 takes those expansible chamber motors in which the motive fluid within an expansible chamber is heated or cooled, as, for example, by a fluid in heat exchange relation with the interior of the chamber. Such a fluid may be the same motive fluid used in the chamber either before or after it passes through the chamber. See Class 60, subclass 508. (4) Heating, Superheating or External Generation. An expansible chamber motor having nominally claimed means to heat or superheat the motive fluid before introduction into the expansible chamber is not precluded from Class 91. For example, Class 91 takes a "boiler" combined with an expansible chamber motor while a "fire tube boiler" combined with a Class 91 motor would be classified in Class 60. See, for example, Class 60, subclasses 643-684. Class 91 does not take the combination of an expansible chamber motor with an explosive generation of motive fluid even if nominally claimed. See, for example, Class 60, subclasses 632-638. (5) Exhaust Treatment or Handling. Class 60 takes combinations involving treatment of motive fluid after it leaves an expansible chamber where means is claimed to change some characteristic of the fluid. A condenser is an example of such a means, but the inclusion of a condenser in a claim by name only is not sufficient to preclude a patent from Class 91. Class 60 also takes combinations involving handling of exhaust fluid from a fluid motor. This fluid is considered to be exhaust fluid for Class 60 after it leaves the last claimed valve means which could affect operation of the Class 91 motor. Handling is considered to necessarily include more than a mere pipe or chamber to conduct the exhaust fluid away. A valve for controlling a Class 91 motor, located in the exhaust line from the motor, designed to direct exhaust fluid to one or more of a number of exhaust passages is not exhaust fluid handling for Class 60. However, an exhaust fluid conductor having a number of ports therein merely for the purpose of dividing the exhaust stream is more than a mere chamber or pipe and is classified in Class 60. Claimed limitations to an elbow, support or other fitting which constitutes a mere part of the exhaust pipe will be ignored, but any significant relation of the pipe and motor will result in classification in the appropriate exhaust treatment subclass of Class 60. A particular physical relation or mechanical interconnection between a chamber or reservoir for receiving exhaust fluid from the motor and the motor has been considered exhaust handling for Class 60. C. Pulsators Class 60 takes pulsator systems in which a generally constant mass of confined motive fluid passes between pump and motor expansible chambers and returns to the pump by the same route or conduit. Class 60 also provides for such pulsator systems where additional fluid is added to the system whether the fluid is make-up fluid to replace leakage or pressurized motive fluid to operate the motor, unless the pressurized motive fluid is valved by a movable valve element which is mechanically connected to the pump working member so that movement of the working member will cause movement of the valve element. The latter combination is classified in Class 91. See the Search Class 60 note in subclass 6 of Class 91 for a further statement of this line. It is to be noted that some pulsator systems which involve a generally constant mass of confined motive fluid include a valve such as a throttle between the pump and motor. The claiming of the motor and valve only in such a disclosed system is excluded from Class 91 in that the fluid does not exhaust to some place other than whence it came. Search Class 60 subclasses 533-594 for pulsators and pulsator systems. RELATIONSHIP TO CLASS 418 Class 418, Rotary Expansible Chamber Devices, takes rotary expansible chamber motors even though the disclosure and claims may be restricted to motor use. In some ways Class 418 may be considered to be less comprehensive than Class 91, and rotary expansible chamber type motors in certain combinations enumerated below will be classified in Class 91 rather than Class 418. Unless specifically excluded below a patent to a rotary expansible chamber type motor as defined in the class definition of Class 418 will be classified as an original in Class 418 as opposed to Class 91. (1) Valving (a) Cyclic or Position Responsive: Class 418 will take rotary expansible motors combined with valves for the motive fluid which have a repetitive pattern or cycle of operation which is related to the rotation of the motor. These may be termed cyclic or position responsive valving and include the opening and closing of inlet or exhaust ports by the movement of this type valving so as to provide, for example, early cutoff of supply is also included in Class 418. The inclusion, however, of means to cutoff operation of the motor after a partial, full or predetermined number revolutions is excluded from Class 418 and would cause classification in this class (91). See for example, subclass 2. (b) In-line: An in-line valve is defined as one situated in the normal line of motive fluid flow which acts in some way to control the flow in the line, but not by diverting the fluid to a second or subsidiary flow line, e.g., waste, etc. Class 418 will take all in-line valves combined with a rotary expansible chamber motor which are controlled by some means other than a condition of the motive fluid, e.g., manual throttle, etc., and will also take those which are actuated directly by the application of the motive fluid thereto, i.e., direct response valves. Those devices including in-line valves which are controlled by a motive fluid condition, e.g., pressure, flow, etc., and in which said valves are not of the direct response type are excluded from Class 418 and will be classified in Class 91 if otherwise appropriate. (c) Branched Flow or By-pass: (1) Separate Valve Means: Those rotary expansible chamber devices which include a separate valve means (as opposed to a movable chamber part as discussed in paragraph (2) immediately below) to divert or by-pass all or a portion of the motive fluid from its normal or first course of flow to a second or waste path are excluded from Class 418 regardless of whether the valve is manually or otherwise controlled unless the diverted fluid is used merely for a motor perfecting function such as lubricating, cooling, vane bias, etc. (2) Movable Chamber Part: Many rotary expansible chamber motors have expansible chamber parts which are in running contact with other chamber parts and which move from a "normal" or contacting position to a noncontacting position and in so moving allow passage or by-pass of motive fluid thereby. Examples of such parts are vanes, abutments, end plates, etc., and such parts are usually biased into contacting position by means such as a spring, pressure fluid conducted from the expansible chamber or the like. Such devices are not excluded from Class 418 even though the yielding of the part may be considered to be performing a by-pass function. However, if motive fluid is conducted to the part for such a biasing function, e.g., behind end plate, etc., and there is a controlled application of fluid to or release of the fluid from the bias area for the disclosed purpose of by-passing said fluid or conducting it to another point of disposal such devices are excluded from Class 418 and are classified in Class 91 if otherwise appropriate. (3) With Diverse Motor: The combination of a rotary expansible chamber motor with another motor of a different type, e.g., reciprocating, etc., is excluded from Class 418. Unless the diverse motor is a mere auxiliary of the rotary expansible chamber motor, as for example, a valve actuating motor. See Class 91, subclass 61 for a combined rotary expansible chamber motor and a reciprocating motor. See Class 60, Power Plants, subclasses 698-720, for other diverse motors one of which may be of the rotary expansible chamber type. The Search Class notes below also include statements of the line with other classes.

SECTION III - REFERENCES TO OTHER CLASSES

SEE OR SEARCH CLASS:

60,	Power Plants, see (4) Note above for the relationship of Class 91 and Class 60.
73,	Measuring and Testing, subclasses 232 through 271for expansible chamber type volume or rate of flow meters. Class 73 includes expansible chamber meters combined with registering mechanism and meters incapable of general use as an expansible chamber motor. A meter is considered to be incapable of such general use if there is not disclosed means to take power therefrom for external use such as to a registering mechanism. Therefore, Class 91 takes an expansible chamber device disclosed as a meter having means to take power therefrom such as for an unclaimed registering mechanism.
74,	Machine Element or Mechanism, appropriate subclasses for machine elements and mechanisms, per se, and in combination with a nominally claimed expansible chamber motor. In general gearing or linkage included as part of the power output means from an expansible chamber motor is considered to be basic subject matter of the motor and would not preclude classification in Class 91. Also see (2) Note, in subclass 55 of Class 91. For statement of the line between Class 74 and Class 92, see section III of the class definition Class 92.
92,	Expansible Chamber Devices, see (3) Note above for the relationship of Class 91 and Class 92.
123,	Internal-Combustion Engines, The line between Class 91 and Class 123 is one of disclosure. Thus, any patent which has at least one embodiment of the invention which is disclosed as an internal combustion engine, and which has a claim specific to such embodiment, and in which the claim includes control of the motive fluid, is classified in Class 123 even though the motive fluid control is not necessarily limited to internal combustion operation.
137,	Fluid Handling, subclasses 82 through 86,for pressure modulating relays or followers for expansible chamber motors. The positive inclusion in a claim of the expansible chamber motor which is controlled by the pressure modulating relay or follower precludes classification in Class 137 and causes classification in Class 91. See, for example, subclasses 3, 47-51 and 52 of Class 91. See subclasses 87.01-87.06, 455-543.23 and 561-616.7 for self proportioning or correlating systems, line condition change responsive valves and multiple or multi-way valves for expansible chamber motors, respectively. The positive inclusion in a claim of the motor which is being controlled by the valve means precludes classification in Class 137. The inclusion in a claim of a cylinder in combination with a valve will not exclude a patent from Class 137 on the basis that a cylinder is the equivalent of a flow path being controlled by the valve. However, where a cylinder is claimed as having passages leading to or ports present in opposite ends thereof (as in a double acting motor) the patent is excluded from Class 137. Also see (2) Note in section I above.
172,	Earth Working, appropriate subclasses, and especially subclasses 2 through 12,464-466 and 491 for expansible chamber motor operated or adjusted implements and see the reference to Class 91 in the Search Class section of Class 172 for a statement of the line.
173,	Tool Driving or Impacting, appropriate subclasses for an expansible chamber fluid motor in a claimed combination peculiar to tool driving, such as a tool drive means combined with a tool impacting, work cleaning, tool advancing or manipulating handle feature. See the class definition of Class 173 for a complete description of the subject matter provided for therein. Also see the reference to Class 91 in section IV of the class definition of Class 173.
180,	Motor Vehicles, subclasses 53.1 through 53.8for vehicles with power take-off means from the vehicle motor to a nominally claimed load.
187,	Elevator, Industrial Lift Truck or Stationary Lift for Vehicle, especially subclass 215 for an expansible chamber fluid motor and its control in claimed combination with a more than named stationary lift for raising a vehicle in its entirety between spaced vertical positions, and subclasses 272-275 for an expansible chamber fluid motor and its control in claimed combination with a more than named load-underlying support surface, e.g., external load support guide structure which is not necessary to the fluid motor internal drive, particular load-underlying support structure, elevator counterbalances, etc.
251,	Valves and Valve Actuation, appropriate subclasses for valves and valve actuators for expansible chamber motors. The positive inclusion in a claim of the motor which is being controlled by the valve precludes classification in Class 251. The inclusion in a claim of a cylinder in combination with a valve will not exclude a patent from Class 251 on the basis that a cylinder is the equivalent of a flow path being controlled by the valve. Also see (2) Note in section I above.
415,	Rotary Kinetic Fluid Motors or Pumps, appropriate subclasses for a rotary motor operated by a confined or directed fluid but not inclusive of "expansible chamber" type classifiable in Class 418, Rotary Expansible Chamber Devices.
417,	Pumps, appropriate subclasses for expansible chamber pumps. Many expansible chamber devices, are capable of use either as a pump or a motor without modification, the only difference being whether pressure fluid is introduced, and mechanical power produced (motor) or mechanical power is introduced and pressure fluid produced (pump). The following criteria will determine original classification if a patent: (a) Where the disclosure is that the device can be used as a pump or motor, classification in Class 91, will result if the device is claimed as a motor or alternatively as pump or motor, or generically as an expansible chamber device, for example. If such a device is claimed as a pump classification will be in Class 417. (b) Where the device is solely disclosed as a pump, classification in Class 417 will result whether claimed generically or specifically. (c) Where the device is solely disclosed as a motor, classification in Class 91 will result whether claimed generically or specifically. (d) Where the device is disclosed and claimed generically, classification in Class 91 will result. (e) For an exception to this general line see subclasses 269 through 273of Class 417 and (1) Note in subclass 269 for the line between the art classified thereunder and the art in Class 91, subclasses 472-507.
475,	Planetary Gear Transmission Systems or Components, for planetary gear transmissions, per se. The same line exists between Class 91 and Class 475 as exists between Class 91 and Class 74.
477,	Interrelated Power Delivery Controls, Including Engine Control, for interrelated control between an engine and a transmission, clutch, or brake. Class 477 was formed from patents in Classes 74 and 192 and so the same line exists between Classes 91 and 477 as exists between Class 91 and Classes 74 and 192. subclasses 375+ for expansible chamber motor driven pumps. The claiming of the pump by name only is not sufficient to exclude a patent from Class 91, the pump or piston and cylinder being considered a nominal load or the equivalent of a crosshead and guide for the motor.

SECTION IV - GLOSSARY

See (3) Note of subclass 418 of Class 91 for definitions of terms applicable to subclasses 418-470 only.

CYLINDER

A rigid external member which permanently surrounds the piston, the latter constituting a relatively moving wall for the expansible chamber, the other walls of which are formed by the cylinder, and the cylinder ordinarily including the abutment or reaction surface against which the motive fluid acts or the piston forming the abutment for the cylinder when the cylinder is movable and the piston fixed. However, the abutment or reaction surface for the piston need not necessarily be formed by the cylinder, but may be formed by a second relatively movable opposed piston within the cylinder. If the piston withdraws from the cylinder merely to control the motive fluid, the piston is still considered to be permanently surrounded by the cylinder.

DISTRIBUTOR

Means which comprises or includes a part which is movable relative to the working member of a cyclically operable motor to control a motive fluid port or passage in such a manner as to cyclically control inlet and/or exhaust flow of motive fluid to or from the motor. The distributor need not entirely cut off the motive fluid flow, but may cyclically control the amount of flow (i.e., throttling).

MOTIVE FLUID

The fluid (expansible or inexpansible) which is introduced into or withdrawn from a working chamber of the motor to cause the working member to move. The term "motive fluid" applies to the fluid from the point of origin to the point of disposal. Fluid which is withdrawn from the motive fluid supply to perform some other motor function, such as motor valve operation, is still considered to be motive fluid even though said fluid never enters the working chamber of the motor. Atmospheric air which acts upon the working member of a vacuum motor is not considered to be motive fluid unless the atmospheric air is controlled in some manner, as by valving. In a vacuum motor the fluid which is evacuated from the working chamber is considered to be exhaust motive fluid and the atmospheric air, if controlled, is considered to be inlet motive fluid.

NON-WORKING CHAMBER

A chamber of the motor which expands and contracts incident to movement of the working member, and which is neither expanded nor contracted to do work by fluid supplied to or evacuated from said chamber.

WORKING CHAMBER

A chamber into which motive fluid is introduced or from which motive fluid is withdrawn (vacuum) to cause the working member to move to perform work, the chamber expanding or contracting incident to the movement of the working member. A chamber of a vacuum motor to which atmospheric air has free ingress and egress without any control thereof is not a working chamber. However, a chamber of a vacuum motor in which atmospheric air acts and some control is exercised over the atmospheric air is a working chamber.

WORKING MEMBER

A movable wall of the expansible chamber to which motive fluid is applied or to which atmospheric air is applied in the case of vacuum motor, said wall moving as a result of the application of the motive fluid and in so moving doing work for utilization by means other than the motor or some part thereof. In a reciprocating motor this term is generic to both a moving piston and a moving cylinder. The working member is considered to include the movable wall to which motive fluid is applied as well as all parts which are rigid therewith, e.g., piston rod, etc. However, a pair of separate movable walls disposed in separate working chambers (i.e., chambers which are not in fluid communication during at least some part of the operation of the motor), even though rigidly connected together, are considered to be plural working members if the application of motive fluid thereto urges both walls in the same direction. A working member has a single working surface which surface may have two or more relatively movable faces so long as adjacent faces are always an extension of each other, e.g., flexible diaphragm or bellows, etc.

SUBCLASSES

[List of Patents for class 91 subclass 1]

WITH SIGNAL, INDICATOR OR INSPECTION MEANS:

This subclass is indented under the class definition. Apparatus having (1) signals, indicators, registers, recorders, or gauges for indicating a condition or the position of a motor part such as a piston, control member, valve, etc., such devices consisting of relatively movable, changeable or audible information giving parts, or (2) transparent viewing means whereby the motor operation or the condition of some part thereof may be observed.

(1) Note. For classification under part (1) of this definition there must be either an indicia or an audible or visual signal. Relative to indicia, there must be graduation or markings in the disclosure as claimed. Where it is indicated that the mere position of a motor part is indicative of a condition of the motor (e.g., valve handle position corresponds to motor position, etc.) classification under this definition does not result unless some cooperating indicia are included.

SEE OR SEARCH CLASS:

73,	Measuring and Testing, subclasses 232 through 271for expansible chamber type volume or rate of flow meters and see section III of the class definition of this class for a general statement of the line between this class and Class 73.
92,	Expansible Chamber Devices, subclass 5 for signals indicators or inspection windows for expansible chamber devices.
340,	Communications: Electrical, subclasses 500 through 693.12for electrical automatic condition responsive indicating systems.

[List of Patents for class 91 subclass 2]

CUTOFF OR CONTROL AFTER PREDETERMINED NUMBER OF CYCLES OR REVOLUTIONS:

This subclass is indented under the class definition. Apparatus in which the motor has a working member which operates through a given cycle, i.e., from a given position through a revolution or reciprocation back to the starting position so as to be in condition to repeat the cycle, and having means for stopping or modifying the operation of the motor responsive to working member travel through a definite preselected number of cycles greater than one.

(1) Note. This definition does not include those motors which operate for a predetermined period of time and then are stopped or controlled in some way even though for a given speed it could be determined how many cycles or revolutions would be made in a given period of time.

SEE OR SEARCH THIS CLASS, SUBCLASS:

35	through 40, for expansible chamber motors having means to start, stop or change the mode of operation thereof after passage of a predetermined time. See (1) Note above.
355	through 356, for motors having control means to cut off the motor after the working member has made one complete cycle of operation.

[List of Patents for class 91 subclass 3]

JET CONTROL TYPE:

This subclass is indented under the class definition. Apparatus including means for providing a jet stream of motive fluid and a receiving orifice to receive all or a portion of the jet stream, motive fluid being conducted from the orifice to a working chamber of the motor to cause operation thereof, movement of the motor being controlled by varying the proportion of the jet stream which enters the orifice.

SEE OR SEARCH CLASS:

137,	Fluid Handling, subclass 83 for jet control type pressure modulating relays or followers, per se.

[List of Patents for class 91 subclass 4]

HYDRO-PNEUMATIC:

This subclass is indented under the class definition. Apparatus in which the motor is provided with a quantity of trapped liquid which is applicable to the working member to move same, means to apply pneumatic pressure directly to said trapped liquid to actuate said working member and valve means for controlling the pneumatic fluid.

(1) Note. Pneumatic fluid under this definition is considered to be any fluid in the gaseous state.

SEE OR SEARCH CLASS:

60,	Power Plants, subclasses 547.1 through 547.3for hydraulic pulsators, i.e. a motor piston and pump piston with a trapped quantity of fluid there-between, and means to apply pneumatic pressure to the pump piston to actuate the motor piston.
92,	Expansible Chamber Devices, subclass 81 for expansible chamber devices in which the working member forms a reservoir for noncompressible working fluid and subclass 142 for expansible chamber devices having a reservoir for noncompressible working fluid.

[List of Patents for class 91 subclass 5]

WORKING MEMBER MOVED BY STORED MOTIVE FLUID CHARGE:

This subclass is indented under the class definition. Apparatus in which the working member of the motor is operated by a charge of expansible motive fluid which has been completely isolated in a storage chamber separate from the expansible chamber; i.e., the storage chamber at a given time is cut off from both the source of supply and the expansible chamber.

(1) Note. The storage chamber generally holds only a sufficient quantity of motive fluid for one stroke of the working member and is recharged before each succeeding stroke.

(2) Note. The charge of motive fluid from the storage chamber may constitute the only motive fluid for impelling the working member or may be supplemented with additional motive fluid.

(3) Note. The storage chamber may not be another expansible chamber of the motor or another motor.

[List of Patents for class 91 subclass 6]

FLUID SUPPLY THROUGH DIVERSE PATHS TO SINGLE EXPANSIBLE CHAMBER:

This subclass is indented under the class definition. Apparatus in which a working chamber of the motor is provided with inlet motive fluid which is supplied from different sources at different times or flows through supply paths that are different at the will of the operator or under different operating conditions so as to supply force to act on the same face of the working member at different times.

(1) Note. The supply paths are considered to be different under this definition if the motive fluid flows through one path at one time and flows through the same path and additionally through another path at another time.

(2) Note. Different positions of the motor working member are considered to be different operating conditions under this definition.

(3) Note. Inlet motive fluid under this definition is considered to be any fluid supplied to the expansible chamber during expansion thereof for the purpose of driving the working member. Also, motive fluid which is admitted to a contracting chamber to cushion the working member prior to admission of motive fluid to expand the chamber is also considered to be inlet motive fluid.

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282	through 283, for cyclically operable expansible chamber motors having a fluid actuated distributor with fluid supplied to the distributor motor through diverse flow paths.
436,	for expansible chamber motors in which inlet fluid to an expanding working chamber is selectively supplemented by fluid pressurized in the contracting chamber.
441,	for expansible chamber motors in which a valve is provided to permit ambient fluid to be drawn into a working chamber thereof as, for example, when the load is moving the working member to expand the chamber faster than inlet fluid can be supplied.
464,	for double acting expansible chamber motors having means to simultaneously open opposed working chambers to inlet motive fluid.

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60,

Power Plants, subclasses 563 through 564for pulsator systems in which the normally constant mass of motive fluid confined between pump and motor chambers of a pulsator system is increased by the addition of pressurized motive fluid from a valve-controlled motive fluid supply means so that the motor is supplied with motive fluid from diverse flow paths. Inclusion of any details of the pulsator pump, for example, reciting the piston or even reciting broadly the type of pump, e.g., "pulsator pump," is sufficient to cause classification in Class 60 although patents merely reciting a "pump" will be classified in Class 91, subclasses 6-33 even where the pump is disclosed as being a pulsator type. It is to be noted that a pair of pistons of the same size in the same uniform diameter cylinder with a confined body of fluid therebetween is not a pulsator system, but is considered to be a mere transmission or two piece piston and does not preclude classification of a patent in Class 91. The combination of two pistons in the same cylinder with an additional, controlled supply of motive fluid to the space therebetween, is construed as a means to vary the size of the piston and thus limit the stroke or alternatively, as a Class 91 type working chamber which, after expansion, is filled with locked up fluid which may constitute a fluid link transmission to transmit the output of another working member. See, for example, subclasses 167-168 of Class 91. Also see section C of (4) Note of the class definition of Class 91; and subclasses 17 and 51 for specific pumps which form diverse paths and sources of pressurized fluid for a Class 91 motor. See (4) Note under the class definition of Class 91 defining the degree of specificity of the pump which results in classification of Class 60.

[List of Patents for class 91 subclass 6.5]

6.5

Three or more cylinders arranged in parallel, radial or conical relationship with rotary transmission axis:

This subclass is indented under subclass 6. Apparatus comprising three or more cylinders each cylinder being provided with relatively reciprocating piston (includes diaphragm) to thereby form a plurality of working chambers, the cylinders or a transmission element in common operative engagement with said cylinders or pistons being adapted to rotate about a fixed axis; said cylinders being physically arranged in a manner such that their longitudinal axis either (1) intersect at a common point or (2) extend parallel to said axis of rotation, and in which motive fluid is supplied to at least one of said cylinders through diverse flow paths.

(1) Note. Plural cylinder motors of the above defined type in which each cylinder receives motive fluid through different supply paths for the sole purpose of causing more than one expansion and contraction cycle of the working chambers during each complete revolution of 360° of the cylinders of rotary transmission are not intended to form subject matter under this definition and are therefor excluded hereunder.

(2) Note. See note in Class 417, Pumps, subclass 269 for a statement of the line between this class and Class 417 regarding plural cylinder devices of the above defined type.

[List of Patents for class 91 subclass 7]

Selective cyclic and noncyclic operation or parking:

This subclass is indented under subclass 6. Apparatus in which the motor is capable of reciprocatory motion through a cycle by a forward stroke and a return stroke to the starting point and wherein the motor (1) may be operated continuously repeating said cycle without manual intervention with motive fluid being supplied to a working chamber thereof through one supply path or (2) may at the will of the operator, be operated through a full or partial forward or return stroke utilizing a different motive fluid supply path to said working chamber.

(1) Note. The non-cyclic operation may be, for example, for the purpose of operating the motor as a servo motor or for placing the working member in a fixed stopped position or for starting the working member when on dead center.

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282	through 283, for motors which may be made to operate cyclically or noncyclically by supplying fluid through diverse flow paths to a motor which operates a distributor therefor.

[List of Patents for class 91 subclass 8]

Semi-compound type:

This subclass is indented under subclass 6. Apparatus wherein the motor is provided with at least two expansible working chambers, a prior one of the chambers receiving expansible motive fluid and having a passage for exhausting the fluid into a subsequent chamber for expansion therein; and wherein a further fluid passage is provided which may be used to additionally supply motive fluid to the subsequent chamber simultaneously with the exhaust fluid from the prior chamber.

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11,

for expansible chamber motors which operate by multiple expansion, i.e., the motive fluid is supplied to a first working chamber and then discharged to a second working chamber for expansion therein and which may be modified so that inlet motive fluid is supplied directly to the second chamber and the first chamber is exhausted to some place other than the second chamber.

9	Changeable by shiftable distributor:
	This subclass is indented under subclass 8. Apparatus having a valve for distributing motive fluid to and between the working chambers and wherein a movement of the valve from the normal limits of travel during multiple expansion operation opens an additional fluid passage allowing motive fluid to be introduced directly into the subsequent chamber.

[List of Patents for class 91 subclass 10]

With condition responsive change-over valve:

This subclass is indented under subclass 8. Apparatus having a valve means for changing the motor to or from the semicompound type, the valve means responding to some condition of operation of the motor or the motive fluid.

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28,	for an expansible chamber motor in which a second fluid flow path to the motor is opened in response to a pressure or flow condition of the motor.

[List of Patents for class 91 subclass 11]

Changeable from multiple expansion to simple operation:

This subclass is indented under subclass 6. Apparatus comprising two or more expansible working chambers having, in one condition of operation, interconnecting passages whereby a prior one of the chambers receives motive fluid and then exhausts the motive fluid into the subsequent chamber for expansion therein; and wherein additional passage means is provided, in another condition of operation, for introducing motive fluid from the source to the subsequent chamber, the subsequent chamber then receiving no fluid from the first chamber.

(1) Note. This definition does not include motors in which motive fluid is supplied to a first expansible chamber and then directed to a second expansible chamber while the first is still in communication with the supply so as to in effect provide direct communication between the second chamber and the supply.

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8	through 10, for expansible chamber motors of the multiple expansion type wherein motive fluid may optionally be supplied directly to a subsequent working chamber in addition to fluid supplied thereto from a prior working chamber.

[List of Patents for class 91 subclass 12]

Cyclically operable motor with port reversing:

This subclass is indented under subclass 6. Apparatus comprising a cyclically operable motor and motive fluid distributing valve means operated incident to the operation of the motor for causing the cyclic operation and means for reversing the motive fluid flow to and from the motor for a given position of the motor.

(1) Note. The means for reversing the motive fluid flow causes the motive fluid to flow to a given chamber through different paths for the two conditions of operation.

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30,	for expansible chamber motors of other than the cyclically operable type having serially arranged reversing valves.
218,	(2) Note for the definition of a cyclically operable motor.

[List of Patents for class 91 subclass 13]

By Shifting distriburtor seat:

This subclass is indented under subclass 12. Apparatus in which fluid connections to the motor for a given position of the motor are reversed by adjusting the distributor seat, i.e., the part of the distributor which is fixed during normal cyclic operation of the motor.

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218,	(2) Note for the definition of distributor.

[List of Patents for class 91 subclass 14]

By shifting distributor:

This subclass is indented under subclass 12. Apparatus comprising separately actuatable means to additionally operate the distributor of the motor so as to reverse the fluid connections to the motor for a given position of the motor.

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13,	for cyclically operable expansible chamber motors in which the parts are reversed by shifting the distributor seat.
218,	(2) Note for the definition of distributor.

[List of Patents for class 91 subclass 15]

Selector valve between distributor and motor:

This subclass is indented under subclass 12. Apparatus comprising further valve means arranged in series with the distributing valve means and operable to reverse the fluid connections between the distributing valve means and the motor for a given position of the distributing valve means, the further valve means being located between the distributing valve means and the motor.

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30,	for expansible chamber motors of other than the cyclically operable type having serially arranged reversing valves.

[List of Patents for class 91 subclass 16]

Drifting or coasting on lower pressure:

This subclass is indented under subclass 6. Apparatus in which the working chamber is supplied with relatively high pressure fluid to drive the working member and is supplied with a relatively lower pressure fluid when the high pressure fluid is cut off and the motor is coasting, i.e., being driven by the load, to prevent vacuum build-up in the working chamber.

(1) Note. This is an art group in which the momentum of the load, e.g., locomotive, etc., drives the motor working member after the motive fluid has been cut off with lower fluid pressure being supplied when the high pressure supply is cut off. While the lower pressure fluid may not actually drive the working member because of the momentum of the load, it must be supplied in such a manner as to provide a driving force to the working member in the absence of the load. Thus, a simultaneous application of lower pressure fluid to opposed working chambers is not included under this definition.

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437	through 439, for expansible chamber motors having a by-pass between opposed working chambers which is controlled independently of the inlet and exhaust control valve means. The by-pass in many instances is to prevent pressure or vacuum build up in a motor which is coasting.
441,	for expansible chamber motors in which a valve is provided to permit ambient fluid to be drawn into a working chamber thereof as, for example, when the motor is coasting.
464,	for double acting expansible chamber motors having means to simultaneously open opposed working chambers to either inlet or exhaust.

[List of Patents for class 91 subclass 17]

With speed responsive cutoff of drifting fluid:

This subclass is indented under subclass 16. Apparatus in which the lower pressure fluid is cut off from the motor in response to the speed of operation of the motor falling below a given amount.

(1) Note. This definition does not include drifting valves which are controlled by a pressure condition of the motor which pressure condition may incidentally be indicative of the speed of the motor.

[List of Patents for class 91 subclass 18]

Pressure control of drifting fluid:

This subclass is indented under subclass 16. Apparatus in which the lower pressure fluid is controlled by the pressure condition in the higher pressure line or in a motor working chamber.

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28	through 29, for expansible chamber motors in which motive fluid is supplied to a working chamber through different flow paths, the flow in the second path being activated by a pressure or flow condition in the first path.
33,	for expansible chamber motors in which motive fluid is supplied to a working chamber through different flow paths, the activation of one path acting to disable a second flow path by the pressure of fluid acting in said one path as, for example, by a shuttle valve.

[List of Patents for class 91 subclass 19]

Diverse paths used to control extent of working member travel:

This subclass is indented under subclass 6. Apparatus in which the supply of motive fluid to a working chamber of the motor through one path is effective to cause the working member to move to a given position or within a given limited range and then stop and the supply to said working chamber through a second path is effective to move the working member to a different position or through a different limited range and then stop.

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357,	for expansible chamber motor in which the stop position of the working member is controlled by selectively venting any of a number of exhaust ports.

[List of Patents for class 91 subclass 20]

Position responsive:

This subclass is indented under subclass 6. Apparatus in which at least one of the flow paths of the motive fluid supply is controlled as a result of the motor working member or load attaining a given position or is incapable of being controlled until the working member or load has attained a given position.

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5,	for expansible chamber motors having position responsive fluid supply through diverse flow paths to a single working chamber wherein the supply in one path includes a trapped motive fluid charge.

[List of Patents for class 91 subclass 21]

Rotating working member or chamber:

This subclass is indented under subclass 20. Apparatus comprising a rotating working member or chamber.

(1) Note. For class definition glossary for Class 418, Rotary Expansible Chamber Devices.

22	Preliminary inlet to contracting chamber (e.g., cushioning, etc.):
	This subclass is indented under subclass 20. Apparatus in which the motor is of the reciprocating type wherein when the motor working member is moving in one direction and approaching the end of the stroke an initial charge of motive fluid is admitted to the contracting chamber in response to the working member attaining a given position, usually to cushion the movement of the working member, and then an additional charge of motive fluid is supplied through a different supply path to cause the working member to move in the opposite direction on the return stroke.

[List of Patents for class 91 subclass 23]

By bypassing from expanding chamber (399):

This subclass is indented under subclass 22. Apparatus in which the motor is of the double acting type, the initial charge of motive fluid being supplied to the contracting chamber from the expanding chamber.

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399,	for expansible chamber motors in which motive fluid is by passed from an expanding chamber to an opposed otherwise closed contracting chamber so as, for example, to cushion movement of the working member.

24	Additional inlet path opened in response to position:
	This subclass is indented under subclass 20. Apparatus in which a working chamber is supplied with motive fluid through a first supply path and in response to the working member attaining a given position further motive fluid is supplied to said chamber through a second path with the first path remaining open.

[List of Patents for class 91 subclass 25]

Working member or part carried thereby uncovers inlet port:

This subclass is indented under subclass 24. Apparatus in which the second supply path includes a supply port in the working chamber which is closed by the working member or a relatively movable part carried on the working member, the working member or said relatively movable part acting to open said supply port in response to movement of the working member.

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21,	for rotary expansible chamber motors having an additional inlet path opened in response to the position of the rotary working member.

26	First path has check valve or selectively adjustable throttle:
	This subclass is indented under subclass 25. Apparatus in which said first supply path is provided with (1) a self acting valve which opens in response to motive fluid flow to permit substantially unrestricted flow into the working chamber, but is self closing to prevent exhaust flow from the working chamber, or (2) a valve which may be manually operated to vary the flow capacity of said first supply path.

27	Plural simultaneous paths, one cutoff in response to position:
	This subclass is indented under subclass 20. Apparatus in which motive fluid is concurrently supplied to a working chamber through a plurality of flow paths, one of said paths being closed in response to the working member attaining a given position while the other supply path remains open.

[List of Patents for class 91 subclass 28]

Second path activated in response to pressure or flow in first path:

This subclass is indented under subclass 6. Apparatus in which motive fluid is supplied to the working chamber through one path and in response to a flow or pressure condition in said flow path a second inlet flow path to said working chamber is opened.

(1) Note. The working chamber is considered to be part of the flow path. Thus, sensing of pressure in the working chamber to activate the second inlet flow path is included under this definition.

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18,	for cyclically operable expansible chamber motors in which low pressure fluid is supplied to the working chamber when the high pressure fluid is cut off and the motor is coasting or drifting, e.g., locomotive, etc., the low pressure fluid being controlled in response to the pressure in the high pressure line.
33,	for expansible chamber motors having diverse motive fluid supply paths to a single expansible chamber in which the pressure or flow of motive fluid in one path is effective to cut off or deactivate a second supply path.
436,	for expansible chamber motors in which inlet motive fluid to an expanding chamber is supplemented by fluid pressurized in an opposed contacting chamber.

29	By pressure rise in first path:
	This subclass is indented under subclass 28. Apparatus in which the second inlet flow path to the working chamber is opened in response to an increase in pressure of the motive fluid in the first inlet flow path.

[List of Patents for class 91 subclass 30]

Serially arranged reversing valves:

This subclass is indented under subclass 6. Apparatus comprising a double acting reciprocating motor having opposed working chambers, motive fluid inlet and exhaust lines and a pair of valves serially arranged between the inlet and exhaust lines on the one hand and the opposed working chambers on the other hand, each of said valves being controllable to connect the motive fluid inlet to one of said chambers while the other chamber is connected to exhaust or vice versa.

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12	through 15, for a cyclically operable expansible chamber motor and means for reversing the connections of the distributing valve and motor and especially subclass 15 where said means comprises a reversing or selector valve located between the distributing valve and motor.

31	One path includes restriction:
	This subclass is indented under subclass 6. Apparatus in which one of the flow paths to the working chamber has throttling means therein to restrict the flow of motive fluid to the working chamber.

[List of Patents for class 91 subclass 32]

Activation of one path disables second path:

This subclass is indented under subclass 6. Apparatus wherein when motive fluid is supplied to a working chamber through one supply path another motive fluid supply path to said chamber is inactivated and does not supply motive fluid to the chamber when said one supply path is active.

(1) Note. Under this definition the two supply paths must be separate, i.e., one supply path may not include two simultaneous flow lines and the other comprise one of said lines as set forth in (1) Note of subclass 6.