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CLASS 313,	ELECTRIC LAMP AND DISCHARGE DEVICES
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SECTION I - CLASS DEFINITION

This is the generic class for electric lamp and electric space discharge device structure.

Examples of such devices are electric incandescent lamps, gas or vapor filled electric discharge tubes, including lamps, mercury arc devices, vacuum discharge tubes, radio tubes, cyclotrons, cathode-ray tubes, photosensitive discharge devices, secondary emission electron multipliers, spark plugs, and open air arc and spark devices.

SECTION II - LINES WITH OTHER CLASSES AND WITHIN THIS CLASS

For specific class references where not provided in the sections below, see References to Other Classes that refer to the particular section title.

A. LAMPS AND DISCHARGE DEVICE STRUCTURE CLASSIFIED ELSEWHERe

1. X-ray Tubes And Targets - See References to Other Classes.

2. Insulators With Arcing Devices - See References to Other Classes.

3. Lightning Arresters - Class 313 includes lightning arresters where the only structure is an arc or spark gap. Excluded are lightning arresters which include an arc or spark gap in combination with an impedance element such as a resistance, or inductance. Also excluded are arc or spark gap arresters in combination with a circuit maker or breaker such as a thermostatic switch or fuse. Excluded from Class 313 are the lightning arresters of the arc or spark gap type which are designed to have the electrodes brought into physical contact upon a prolonged discharge or which are provided with a material, such as, a fusible substance which melts and flows between the electrodes to short-circuit the electrodes upon a prolonged discharge.

Among the excluded types of lightning arresters is the type including a mass of particulate particles, each particle being insulated from the other, usually by a coating upon the surface of the particle. When a discharge passes from particle to particle, the surface material becomes conductive making a short-circuit through the mass. If the particles remain conductively insulated and the current is transmitted through the mass of particles by the arc or spark, then the device is included within the scope of Class 313.

For the excluded types of lightning arresters see References to Other Classes, below.

4. Electric Lamp Provided With Structure For Holding A Material To Be Heated - See References to Other Classes.

5. Molecular Or Atomic Beam Devices - See References to Other Classes.

6. Mass Spectrometers - See References to Other Classes.

7. Electron Microscopes - See References to Other Classes.

8. Cathode Ray Oscillographs - See References to Other Classes.

9. Consumable Electrode Discharge Devices (e.g., Arc Lamps, etc.) - See References to Other Classes.

10. Lamps And Discharge Devices Having A Circuit Element Included Therein

An electromagnet connected in circuit with an electrode does not prevent classification of a lamp or space discharge device in Class 313 if the electromagnet is an operator for moving an electrode or if the electromagnet generates a magnetic flux which influences the operation of the lamp or space discharge device (see Subclass References to the Current Class, below). The inherent resistance of an electrode, although significant to the operation of the device, is not considered a circuit element such as would prevent classification in Class 313. Also See References to Other Classes.

11. Discharge Devices Structurally Combined With And In Circuit Relation With Incandescent Lamps- See References to Other Classes.

12. Discharge Devices Having The Cathode Heater or Other Structurally Combined Heater In Circuit Relation Therewith- See References to Other Classes.

13. Gas Pumps And Fans- See References to Other Classes.

B. LAMP AND DISCHARGE DEVICE SYSTEMS

This class does not include electric systems for supplying electric current and/or potential to electric lamps or to discharge devices.

Patents which claim a lamp or discharge device having electrodes which are adapted to have current or potential impressed upon the electrodes or which claim a lamp or discharge device with means recited broadly (no specific means, such as a battery, source etc., being included) to impress current or potential on the electrodes are classified in this class as lamps or discharge devices unless some circuit elements are claimed which positively limit the claims to a system rather than to a lamp or discharge device, per se. However, where the relative potentials between the electrodes are claimed, the patent is classified as a system.

For example, a claim to a discharge device having an anode adapted to be maintained at a high positive potential, a control electrode adapted to be maintained at a low negative potential, and a cathode adapted to be maintained at ground potential will be excluded from this class and will be found in the appropriate system class.

For discharge devices and lamp systems, see References to Other Classes, below.

C. METHOD OF OPERATING LAMPS OR DISCHARGE DEVICE

Patents which claim a method of operating a lamp or discharge device are excluded from this class and will be found in the class which provides for the system which is required to operate the device. See above for the classification of electric lamp and discharge device systems. Also See References to Other Classes, below.

D. METHODS AND APPARATUS FOR SUBJECTING OBJECTS, ARTICLES AND MATERIALS TO RAY ENERGY OR ELECTRONS OR IONS GENERATED BY DISCHARGE DEVICES OR LAMPS

Class 313 does not include either processes or apparatus for subjecting materials, articles or objects to the ray energy (e.g., ultraviolet light, X-rays, etc.) or to electrons, ions, arcs or sparks generated by electric lamps or discharge devices.

For such methods and apparatus, see References to Other Classes, below.

E. COMBINED WITH A SUPPORT

Where the support is a casing, jacket, electrical connector (e.g., socket) or includes means for modifying the temperature of the lamp or discharge device, see below.

Lamps including discharge device lamps combined with a supporting means for the lamp are excluded from Class 313.

Class 313 is the generic class for discharge devices in combination with supporting means for the discharge device.

Also See References to Other Classes, below.

F. COMBINED WITH TEMPERATURE MODIFYING MEANS

1. With Enclosing Casing Or Jacket:

Class 313 is a generic class for all discharge devices where significant discharge device structure is claimed in combination with a jacket, casing or enclosure having means to modify the temperature of the discharge device. (See Subclass References to the Current Class, below.)

Included in Class 313 are all lamps, per se, and discharge devices, per se, which are provided with a double walled envelope or two sealed enclosing envelopes, the second envelope being an integral part of the lamp or discharge device structure, the space between the two envelope portions being evacuated or filled with heat transfer or insulating means to modify the temperature of the lamp or discharge device. (See Subclass References to the Current Class, below.)

See References to Other Classes, below.

2. Lamp, Discharge Devices, And Envelopes Therefor With Temperature Modifying Means

Class 313, provides for all lamp and discharge device structures, per se, where significant lamp or discharge device structure is claimed and which include means for modifying the temperature of the lamp or discharge device, excepting lamps and discharge devices of the consumable electrode type which are classified elsewhere. (See References to Other Classes, below.)

See above when the lamp or discharge device is provided with a separable casing, jacket, or enclosure and which include means to modify the temperature of the lamp or discharge device, and also see above with respect to photocells provided with temperature modifying means where no significant photocell structure is claimed.

See Class 313 for lamp and discharge device structure which include means for modifying the temperature of the lamp or discharge device. Included are lamp and discharge devices, per se, having heating means for raising the temperature of the device, devices with electrodes provided with cooling ducts or heat radiators, devices with means to modify the temperature of the envelope, including double walled envelopes or two sealed enclosing envelopes with a heat conducting or heat insulating medium (including vacuum) in the space between the two envelope walls, devices with heat conducting or insulating members, etc.. Also included is the structure of electrodes for lamps and discharge devices which are provided with means to modify the temperature of the electrode (e.g., electrodes with cooling fins, fluid ducts, heat transmission means, etc.).

Excluded from Class 313 are mere envelopes, for electric lamps or discharge devices provided with temperature modifying means where no significant lamp or discharge device structure is claimed.

Parts of lamps and discharge devices, such as electrode clamps or electrical connectors provided with heat modifying means are classified with the appropriate device, e.g., with the clamp or connector, etc.

G. COMBINED WITH A SEPARABLE CASING, JACKET, SHIELD, OR ENVELOPE PROTECTIVE MEANS

Where the lamp or discharge device and casing or jacket includes means to modify the temperature of the lamp or discharge device, see above.

See below with respect to the classification of lamps and discharge devices provided with an envelope or a nonseparable casing or jacket.

Class 313 is a generic class for the combination of significant discharge device structure and a separable casing jacket, shield or enclosure, or envelope protective means and provides for all discharge devices other than lamps which are not otherwise classified where significant discharge device structure is claimed in combination with a casing, jacket, shield, or envelope protective means. Included in Class 313 are all lamps which have a double wall envelope where the second envelope which encloses the first envelope is integrally united with the first envelope so that the two envelope walls constitute an integral structure. Where the second envelope wall is not integral with the lamp envelope, that is, it is removable therefrom, the patent is excluded from Class 313 and will be found elsewhere. The combination of an envelope, box or housing (such as a lamp or discharge device envelope) and either a separable or integral casing or housing where electrical features are claimed is classified elsewhere. (See References to Other Classes, below.)

See Class 313 for lamps and discharge devices which have an integral double wall envelope; for discharge devices having an envelope and a casing or jacket therefor; for where the discharge device is provided with an electrical shield and for other discharge devices provided with a casing or jacket. (See Subclass References to the Current Class, below.)

Also See References to Other Classes.

H. COMBINED WITH OPTICAL DEVICE OR HAVING SPECIAL RAY TRANSPARENT ENVELOPE (E.G., FILTER, REFLECTOR, LENS, LIGHT DISTRIBUTOR OR MODIFIER LIGHT SHIELD, LIGHT SHADE, ULTRAVIOLET RAY TRANSPARENT PORTION, OR LIGHT OBSCURING MEANS).

Class 313 provides for all lamps and discharge devices which have an integral part of the lamp an optical means combined therewith or which are provided with an envelope at least a portion of which is made of a glass or material especially designed to transmit a particular portion of the spectrum, such as ultraviolet, infrared, or only a restricted portion of the visible spectrum. This includes lamps and discharge devices with light filters, reflectors, refractors, etc. within the envelope of the lamp or coated upon or forming a part of the envelope of the lamp. See Class 313 for this art. See this class (313) for lamps and discharge devices where the claims are limited to the envelope being made of a glass or other material (e.g., quartz) which transmits a particular portion of the spectrum or a restricted portion of the spectrum. (See Subclass References to the Current Class, below.)

See below for the classification of envelopes, jackets, and casings, per se, for lamps and discharge devices.

Class 313 does not provide for any discharge devices or lamps where the optical device is separable from the lamp or discharge device, that is, it is not an integral part of the lamp or discharge device.

See References to Other Classes, below.

J. COMBINED WITH ELECTRICAL CONNECTOR STRUCTURE

Class 313 provides for the combination of all electric lamps and discharge devices where significant lamp or discharge device structure is recited in combination with an electric connector for connecting the lamp or discharge device in an electric circuit. See Class 313 where the lamp or discharge device is combined with a separable or detachable electric connector (e.g., a socket) and where the lamp or discharge device is provided with an electrical connector which is a part of the lamp or discharge device (e.g., a base on the lamp). (See Subclass References to the Current Class, below.)

1. Lamps And Discharge Devices Combined With A Separable Electric Connector

This class (Class 313), Electric Lamp and Discharge Devices) provides for the combination of an electrical lamp with a base or socket including a filament, or other reference to electrodes of the lamp.

See References to Other Classes.

2. Lamps And Discharge Devices Which Include Electrical Connector Structure

For reference to lamps and discharge devices with a base, where no electrical connector structure is involved, see below and References to Other Classes.

3. Electrodes Combined With Connector Structure

Class 313 includes all electrodes for electric lamps and discharge devices where significant lamp or discharge device electrode structure is claimed in combination with an electrical connector for the electrode, or where the electrode is provided with electrical connector structure. Merely reciting that the electrode is a metallic or nonmetallic rod or wire, or that the electrode has a particular cross-section where the connector is attached to the connector is not considered to be significant electrode structure.

See References to Other Classes, below.

K. ENVELOPES, CASINGS AND JACKETS FOR LAMPS AND DISCHARGE DEVICES

Class 313 provides for the combination of electric lamps and discharge devices which are provided with a envelope, and for electric lamps and discharge devices which are provided with a casing or jacket which is an integral part of the lamp or discharge device. Class 313 provides for lamps and discharge devices where the claims are limited to the envelope being made of a glass or other material (e.g., quartz) which transmits a particular portion of the spectrum or a restricted portion of the spectrum. See Class 313 for lamps and discharge devices with envelopes, and for discharge devices and lamps with casings or jackets. (See Subclass References to the Current Class, below.)

See discharge devices which are provided with separable casing, jacket, shield or envelope protective means, and References to Other Classes, below.

1. With Attached Base

Where the attached base includes electrical connector means see above and References to Other Classes, below.

2. With Lead-in Structure

Boxes, housings, and envelopes for electrical devices including electric lamps and discharge devices where the box, housing or envelope includes means to couple a conductor to the box, housing, or envelope, or has means for passing a lead-in conductor into the box or housing are classified elsewhere. Boxes, housings, and envelopes which are provided with other significant electrical structure or which are claimed as having an electrical device therein where no significant characteristics of the electrical device are recited are elsewhere. (See References to Other Classes, below.)

Note that if the lead-in conductors are of such rigidity to form contacts (usually plug-type contacts), the device is classified elsewhere unless significant structure of the device in addition to the connector structure is recited as pointed out above. Any specification of electric lamp or discharge device structure in addition to naming the type of lamp or discharge device will cause classification of the patent in Class 313. Where the claims are drawn to an electrical device broadly defined within the envelope, the patent is classified elsewhere. Claims which are drawn to a discharge device or electric lamp or a particular type, such as a gas filled discharge device, or an incandescent lamp where only envelope and lead-in structures are claimed are classified elsewhere.

For lead-in and seal structure such as glass to metal seals, see below.

3. With Identifying Indicating Mark- See References to Other Classes.

4. Defined Only By Composition

Envelopes, jackets and casings which are defined only by their composition will be found in the appropriate composition class.- See References to Other Classes, below.

5. Structure- See References to Other Classes, below.

L. BUSHINGS, GLASS-TO-METAL SEALS AND LEAD-IN CONDUCTORS

See above for lamps and discharge devices which are provided with electrical connector means such as a base having prongs thereon and which sometimes include bushings or lead-in conductors for conducting electricity through the wall of the housing, jacket or envelope of the lamp or discharge device to the electrodes within the casing, jacket or envelope. See above for housings, jackets, and envelopes for electric lamps and discharge devices which are provided with lead-in or bushing structure for passing electric current through the wall of the housing, jacket, or envelope to the interior of the device.

See References to Other Classes, below.

M. ELECTRODES AND SHIELDS

Class 313 provides for all electrodes and shields, per se, excepting the consumption feed type electrodes classified elsewhere. Class 313 includes electrodes and shields formed of two or more parts with a joint therebetween where significant electrode or shield structure is claimed. Electrodes which are limited by claimed structure to use in discharge devices (arc lamps) in which the feed or motion of one of the electrodes towards the other is accomplished by the destruction of the electrode or a portion thereof due to the discharge are classified elsewhere. (See References to Other Classes, below.)

Electrodes and shields which include no more structure than a base having one or more coatings thereon are excluded from Class 313. Merely naming the electrode or shield as a wire, filament, rod, ribbon or strand is not sufficient structure to cause classification in Class 313. Electrodes and shields which are defined only by their composition are excluded from this class. The excluded art relating to electrodes and shields will be found in the classes listed below:

1. Electrodes And Shields With Joints Therebetween

Where the only structure of the electrode or shield recited is that the electrode or shield is composed of two or more parts with means to join the parts together, the patents will be found in the appropriate class providing for the joint.

See References to Other Classes, below, for a reference to the classes which provide for joint structure.

Where an electrical feature is claimed in addition to the joint but no significant structure other than that required to make the joint is recited, the patent will be found elsewhere for the electrical connector structure. Where an electrode is composed of two rod-like portions and one portion is provided with a hollow screw threaded socket and the other is provided with the screw threaded end to fit into the socket, the patent is classified elsewhere. If the structure includes means such as a portion of higher electrical conductivity to insure good electrical contact between the portions, the patent would be classified elsewhere.

See References to Other Classes, below.

2. Coated Electrodes Or Shields And Compositions- See References to Other Classes, below.

3. Methods And Apparatus For Manufacturing Electrodes- See References to Other Classes, below.

N. FLUORESCENT AND PHOSPHORESCENT COATING AND COMPOSITIONS

Class 313 provides for electric lamps and discharge devices where significant lamp or discharge device structure is claimed which include as a part thereof a fluorescent or phosphorescent material. See this class (313) for cathode-ray tubes which have a fluorescent or phosphorescent target and for other discharge devices and lamps having an electrode or the envelope coated with or containing a fluorescent or phosphorescent material, or which otherwise include as a part thereof a fluorescent or phosphorescent material.

See References to Other Classes, below.

O. GETTERS AND GAS OR VAPOR GENERATING MATERIALS

Class 313, provides for all electric lamps and discharge devices which have combined therewith a getter or a gas or vapor generating material, irrespective of whether the getter or gas or vapor generating means, is to be used during the manufacture of the device, or to be used during the operation of the device, or to be used as needed after the device has been operated. Class 313 also provides for electrode structure combined with containers or receptacles for the getter or the gas or vapor generating material. For electrodes which involve significant electrode structure with a coating or a getter material thereon, see this class (313). For the classification of electrodes which involve only a base with a coating of a getter material thereon, or which involves only an electrode defined by its compositions, see above.

See Subclass References to the Current Class, below, and References to Other Classes, below.

P. DEFLECTION AND FOCUSING MAGNETS

Magnets provided with a plurality of coils to deflect the cathode ray in a plurality of directions, (e.g., vertically, and horizontally) are classified elsewhere. Magnets for focusing, concentrating or accelerating cathode rays even if the magnet is provided with a plurality of separate coils are elsewhere. Magnets for cathode-ray tubes which have a plurality of coils to generate both a deflecting field and a focusing, concentrating and/or accelerating field are classified in Class 313.

See References to Other Classes, below.

Q. INFRARED RAY GENERATORS

Class 313 does not provide for devices for converting electrical energy into infrared ray energy, excepting in special cases. Many lamps and discharge devices inherently generate infrared ray energy in their operation. Class 313 will take therefore, electric lamps and discharge devices which are stated to be for the purpose of generating infrared ray energy when such lamps and discharge devices are substantially identical in structure with lamps and discharge devices intended to generate visible light or ultraviolet light or other analogous ray energy. Class 313 will take such devices even though the device includes means for preventing light energy other than the infrared ray energy from being emitted, such as having the envelope wall formed of an opaque material. Such infrared ray generators are classified in Class 313 in the subclasses providing for the structure of the analogous lamp or discharge device, see especially where the lamp or discharge device has an envelope made of the material which is especially transparent to infrared ray energy and where the lamp or discharge device is provided with a light obscuring means such as an opaque coating on the envelope wall. (See Subclass References to the Current Class, below.)

Class 313 does not provide for the infrared generator in combination with a reflector, guard, support, separable casing, or jacket. For such excluded subject matter and other infrared ray generators see References to Other Classes, below.

R. METHODS AND APPARATUS FOR MANUFACTURING OR REPAIRING ELECTRIC LAMPS OR DISCHARGE DEVICES OR SALVAGING PARTS THEREOF

Class 313 does not provide for the processes or apparatus used either to manufacture or repair electric lamps or discharge devices. It should be noted, however, that Class 313 does provide for electric lamp and discharge devices which are provided with a getter, a gas or vapor generating means, or pressure regulating means, see above. (See Subclass References to the Current Class, below.)

S. SYSTEMS, APPARATUS AND METHODS FOR TESTING ELECTRIC LAMPS AND DISCHARGE DEVICES

See References to Other Classes.

T. RELATIONSHIP OF CLASSES 313 TO 445, ELECTRIC LAMP OR SPACE DISCHARGE COMPONENT OR DEVICE MANUFACTURING

In view of the statements in the above sections, the relationship between the classes and subclasses mentioned can be shown in schedule form thus:

313, Electric Lamp and Discharge Devices

314, Electric Lamp and Discharge Devices: Consumable Electrodes

315, Electric Lamp and Discharge Devices: Systems

445, Electric Lamp or Space Discharge Component or Device Manufacturing

U. DISTINCTION BETWEEN DISCHARGE DEVICES AND ELECTRIC SWITCHES

Some types of electric switches are closely analogous in structure to some types of discharge devices. This is especially true with respect to the type of discharge device where the electrodes of the discharge device are placed in contact and then separated from each other to establish the discharge. Some types of switches include means, such as electromagnets, to extinguish the arc between the switch contacts when the switch is opened. Some types of discharge devices include means, such as electromagnets, to defect or otherwise alter the characteristics of the discharge between the electrodes.

The distinction between electric switches and discharge devices, therefore, depends in some cases principally upon the disclosed purpose of the structure claimed by the patent. Where the discharge is only an incident to the separating of the switch contacts and the purpose of the structure is to open or close a circuit, the device will be considered an electric switch for the purpose of classification. When the electrodes are placed in physical contact to close the circuit, and separated from each other to interrupt the circuit, the device will be classified as a switch. Where the purpose of the claimed structure is to establish a space discharge by contacting the electrodes with each other and then separating the electrodes, the device is considered to be a discharge device for Class 313.

Excluded from Class 313 are devices which are designed normally to have a discharge between the electrodes and which include means operative after either prolonged use or overload to establish a short-circuit path from one of the electrodes to the other electrode so as to extinguish the space discharge. See above relative to lightning arresters of this type.

Switches which are somewhat analogous in structure to space discharge devices where the switch is provided with means to separate the switch contacts from each other to open the circuit, the switch structure including means to extinguish the space discharge formed when the switch contacts are opened, are classified elsewhere.

See References to Other Classes, below.

W. DISTINCTION BETWEEN DISCHARGE DEVICES AND ELECTRIC CONDENSERS AND OTHER STATIC FIELD PRODUCING MEANS

Some types of space discharge devices are closely analogous in structure to some types of electric condensers and other static field producing devices. In these cases the device usually consists of two electrodes separated by air, gas, vapor or vacuum and are designed to have an electric potential impressed thereon. Where the device is intended to have a current flow between the electrodes either by ionization or by electron flow, the device is considered to be a space discharge device for Class 313. However, if the device is designed for use without ionization between the electrodes or without transmitting current by electron flow then the device will be excluded from Class 313 and found in the other appropriate class.

Most devices other than the electric condensers of the type referred to above which are excluded from Class 313 are devices for treating materials such as ozonizers, electrical precipitators, disinfecting and sterilizing apparatus.

The Classification of such devices is referred to above. Also See References to Other Classes.

SECTION III - SUBCLASS REFERENCES TO THE CURRENT CLASS

SEE OR SEARCH THIS CLASS, SUBCLASS:

SECTION IV - REFERENCES TO OTHER CLASSES

SEE OR SEARCH CLASS:

SECTION V - GLOSSARY

ANODES

An electrode which acts as the positive terminal of the discharge or which acts as the positive terminal of an electric field to cause a discharge or accelerate the electrons in a discharge. See the definition of cathode above, and the definition of control electrode below.

ANTI-CATHODE

Same as "target" or anode. Used in reference to X-ray tube anodes.

AUXILIARY STARTING ELECTRODE

An electrode designed for use in a discharge device having at least two principal discharge electrodes and the auxiliary starting electrode. The starting electrode is designed to be connected in the circuit so that the discharge is initiated between it and one of the principal electrodes, the auxiliary discharge conditioning the discharge space so that a discharge between the principal electrodes can be established. An auxiliary starting electrode does not necessarily differ in structure or material from any other electrode. Auxiliary starting electrodes are usually simple electrodes, a wire or rod, and are usually not formed from as heavy or strong material as the principal electrodes. Usually an auxiliary starting electrode is placed close to a principal electrode so that the discharge may be initiated between the auxiliary starting electrode and the main electrode at a smaller voltage than is necessary to initiate the discharge between the principal electrodes. The auxiliary starting electrode may be supplied with current only during the starting period or it may be supplied with current during the operation of the device so that a continuous discharge takes place between it an done of the principal electrodes to assure ionization in the discharge space so that the discharge between the principal electrodes may take place at the proper time. The latter type of auxiliary starting electrodes are also known as "holding electrodes". Where a plurality of auxiliary starting electrodes are used, they may be spaced at intervals between the principal electrodes so that the discharge may first be established between one principal electrode and the nearer auxiliary starting electrode, then to a more remote auxiliary starting electrode and so on until the discharge is established between the principal electrodes. If a plurality of auxiliary starting electrodes are used, one may be placed close to each of a plurality of principal electrodes. In as much as the determination of whether or not an electrode is an auxiliary starting electrode depends upon the circuit connections to the discharge device, and this class includes only the structure of the discharge device, per se, only in subclasses 170+ (liquid electrode discharge devices) and subclasses 596+ and 601+ (gas or vapor-type discharge devices) is the classification based upon one of the electrodes being an auxiliary starting electrode.

BASE

A member attached to the lamp or discharge device so that it may be attached to a supporting socket or supported on a surface. The base usually includes electrical connector means for connecting the lamp or discharge device in a circuit. Where the lamp or discharge device is provided with an envelope, the base is usually attached to the envelope, as by cementing, or the envelope is formed so as to have an integral base portion.

CASING

A container or enclosure for a lamp or discharge device, or a part thereof. See Envelope above.

CATHODE

An electrode which acts as the negative device. In some discharge devices, such as spark gaps, there is no difference in structure between the cathode and anode. Consequently, the use of the words "cathode" and "anode" have been avoided except where there is some significance in structure between the two electrodes.

CATHODE RAY DEVICE

A discharge device having means for forming the electric discharge into a restricted beam or ray, usually pencil-like.

CATHANODE

An electrode designed to serve as an anode with respect to a cathode and to be heated by the discharge so that another surface of the electrode emits electrons to a second anode. See subclass 305 for discharge devices having a cathanode.

CONTROL ELECTRODE

An electrode designed to influence or control the discharge current flowing between other electrodes. It may depend for its effect on either its electro-static effect or on the current flow thereto. The most common type of control electrode is the control grid. Since, however, the grid may be used as an anode, and the anode as a grid in many types of discharge devices, the use of the expression "control electrode" has been avoided where possible and similar structures placed together irrespective of whether the disclosure indicated that the grid electrode is to be used as an anode or control electrode. Patents relating to discharge devices having one or more grid electrodes interposed between a cathode and an anode are classified in subclasses 293+ or in the subclasses referred to in the notes to these subclasses. See subclass 308 and the subclasses referred to in the notes thereto for other discharge devices having a control electrode.

DIRECTLY HEATED CATHODE:

A filament designed to have its terminals connected to a source of current, the filament being heated by the current passing through it.

ELECTRIC LAMP

A device for converting electrical energy into visible light or ultraviolet light. Most lamps also generate infrared rays, but infrared ray generators are included only when they have structure analogous to electric lamps or electric space discharge devices. See the notes below. Electric lamps may be in the form of electric space discharge devices, for which see the next paragraph.

ELECTRIC SPACE DISCHARGE DEVICES

(the shorter expression "DISCHARGE DEVICES" is used in these definitions) Any device which is intended to have an electrical current flow between two spaced electrodes, at least part of the path followed by the discharge being constituted by a gas, vapor, or vacuum.

ELECTRODE

A filament or glower of an electric lamp or a member arranged to emit, and/or collect, and/or control the movement of electrons or ions in a discharge device.

EMISSIVE CATHODE

A low work function electrode.

ENVELOPE

A gas tight enclosure for an electric lamp or discharge device. It may be evacuated or filled with a gas or vapor. In general the distinction between an envelope and a mere jacket, casing or housing is that the envelope is sealed, so as to be gas tight.

FILAMENT

A wire, ribbon or rod conducting member. It may be made of metal or nonmetal. In this class filaments, per se, are classified in subclasses 341+ irrespective of whether the filament is to be used in a lamp or discharge device, and irrespective of whether the filament is to be heated by passing a current through the filament (directly heated cathode) or is to be heated by the discharge in a discharge device (see thermionic cathode).

FLUORESCENT OR PHOSPHORESCENT MATERIAL

A material which absorbs radiant energy of one wave length (e.g., light) and is excited thereby to cause it to emit radiant energy of another wave length (e.g., light of another wave length), or a material which is excitable by the impact of electrons, ions, or analogous energy (e.g., gamma rays) thereon to emit light energy without becoming incandescent.

GAS OR VAPOR GENERATING MATERIAL

Solid or liquid material which is placed within the envelope and generates a gas or vapor by virtue of a chemical change, by volatilization, or by giving off an absorbed gas or vapor. It may do this during normal operation or it may be caused to do so by treatment preliminary to placing the device in operation.

GETTERS

Materials which, when used in closed containers, reduce the gas or vapor content of the container. A getter may react with the gas or vapor in the container to form a solid nonvaporizable material, or to adsorb or absorb the gas or vapor, or may reduce the amount of the gas or vapor in the container in any other way. The material may be a getter for one gas or vapor and may not have any effect upon another gas or vapor.

GLOWER

Any body made of a material which when heated by the passage of an electric current therethrough emits light rays. The term glower includes filaments and also includes other bodies which are not of filamentary dimensions such as, rods and bars made of second class conductors.

GRID ELECTRODE

An electrode having one or more apertures therein, usually formed of open-work material, such as wire mesh, perforated sheet material, or of wires or bars as of coiled wire, or other foraminous structure, and sometimes used as the control electrode in a discharge device. As pointed out in the definition of "control electrode" above, the terms "grid electrode" and "control electrode" are not synonymous in this class.

HEATED CATHODE

Either a directly heated cathode or an indirectly heated cathode.

HOLDING ELECTRODES

See the definition of auxiliary starting electrode above.

INCANDESCENT LAMP

Lamps which are provided with a filament or glower adapted to be heated to incandescence by the passage of an electric current therethrough.

INDIRECTLY-HEATED CATHODE (Equipotential cathode)

A cathode designed to be heated to its emitting temperature by a separate heating element.

IONIC CATHODE

A virtual cathode formed by a discharge in a gas or vapor between two electrodes, the discharge serving to supply electrons to a third electrode. See subclass 588 for discharge devices having an ionic cathode.

JACKET

Same as casing above.

LEAD-IN

The conductor used to transmit electric current or potential from the exterior of the envelope or casing into the interior of the envelope or casing. Where the envelope is made of glass it usually consists of a conductor which passes through the wall of the envelope and which is sealed to the glass by a glass-to-metal seal.

LOW WORK FUNCTION ELECTRODE (cold cathode, cathodes containing or coated with electron emissive material)

A cathode containing or coated with a material which readily emits electrons, i.e., a material which has a low work function. Examples of such materials are the alkali metals and their oxides, alkaline earth metals and their oxides, thorium, magnesium. The expression "low work function electrode" includes thermionic electrodes which contain or are coated with electron emissive material, photosensitive cathodes, secondary emissive cathodes as well as cathodes which emit electrons without being heated.

PHOTO-CELLS

A device to be used in an electrical circuit which is provided with means responsive to light or analogous rays for altering the operation of the device. The only photocells included in this class are photosensitive discharge devices and photosensitive electric lamps.

PHOTO-SENSITIVE

A device provided with means sensitive to light or analogous rays for altering the operation of the device.

PHOTO-SENSITIVE CATHODE

An electrode which emits electrons when subjected to the action of light or analogous rays. Discharge devices having a photosensitive cathode or other photosensitive electrode are classified in subclasses 523+ in this class. See photosensitive electrode above. See the class definition for the classification of photosensitive cathodes, per se.

PHOTO-SENSITIVE ELECTRODE

An electrode which has its electrical properties changed by the action of light or analogous ray energy. The ray energy may be X-rays, ultraviolet rays, infrared rays, or any analogous radiation. See the class definition for the classification of photosensitive electrodes, per se.

PYRO-ELECTRIC LAMP

An electric lamp which has as the light emitting body a material which is a second class conductor. The lamps are designed to have the pyro-electric body heated by a separate source until the pyro-electric material becomes conductive and then the current flow through the pyro-electric body maintains the second class conductor material at a temperature at which it emits light.

SECOND CLASS CONDUCTORS

A material having a very high electrical resistance at ordinary temperatures and a low resistance when heated. Glowers formed of oxides, such as Th² or the rare earth oxides, used in the pyro-electric (e.g., Nernst) type of incandescent lamp are examples of second class conductors.

SECONDARY EMISSIVE CATHODE

A cathode designed to emit electrons by virtue of the impact by electrons upon the electron emissive surface. See the class definition for the classification of secondary emissive cathodes, per se. See cathanode below.

SHIELDS

Structures used in lamps and discharge devices to modify the electrical characteristics thereof, or structures which are used to protect the lamp or discharge device from external influences, or structures which are used to protect parts of the device from influences, such as electron bombardment, originating in another part of the device, and other structures used for protective purposes. Shields do not include mere electrodes even though the electrode is defined as being a shielding electrode. Where an electrode of a discharge device is provided with shielding structure in addition to the structure provided for influencing the electric space discharge, such additional structure is considered to be shielding structure. Examples of such additional shielding are where an indirectly heated cathode is provided with a flange for shielding the discharge space from the influence of the cathode heater current, or where an anode, grid, or lead wire is provided with shielding means to shield the lead-in wires from the effects of electrostatic fields. Metal or conductive envelopes for discharge devices are not considered to be shields where the envelope is designed to function as an electrode of the discharge device, such as an anode. Where the metal or conductive envelope is disclosed as being provided for shielding purposes and not an electrode, the envelope is considered to be a shield.

SPARK PLUG

A unitary spark gap having a plurality of insulated electrodes arranged out of contact with each other so that the space discharge is a "jump spark" and usually having a shell or sleeve designed to be attached to an opening in an internal combustion engine or other device, the shell or sleeve carrying one or more electrodes within it which are insulated from the shell or sleeve by an insulating bushing or other insulation. The shell or sleeve often carries an electrode which cooperates with the other insulated electrode to form the jump-spark gap. Included are the devices known as spark plugs usually used on the ordinary automotive internal combustion engine. Also included are spark plugs for other uses which are similar in structure. It does not include ignitors where the spark is made by moving the electrodes into contact and then separating them to draw the spark. It does not include ignitors which are not similar in structure to the automobile spark plug even if they are of the jump spark type. Spark plugs having only a single electrode which are designed to be used with some other device, as the cylinder head, so as to form a jump spark therewith are also excluded.

TARGET

In an X-ray tube, cathode-ray tube, or other beam type discharge device, the anode or the member against which the principal electron or ion stream impinges. See the definition of anode above.

THERMIONIC CATHODE

A cathode designed to operate at an elevated temperature. The expression, "thermionic cathode" includes directly heated cathodes, indirectly heated cathodes, and also cathodes which are designed to be heated by ionic bombardment to the electron emitting temperature.

THREE OR MORE ELECTRODE DISCHARGE DEVICES

Any discharge device having three or more electrodes whether all of the electrodes have lead-wires for connection to the supply circuit or not. In some of the three or more electrode discharge devices, the electrodes are arranged with one or more electrodes disposed in the interelectrode space or in the discharge path between two other electrodes, and have only the outer electrodes provided with lead-wires for connecting to the supply circuit, the discharge passing from the outer electrodes to the interposed electrode so that the discharge device has a plurality of series connected discharge spaces.

X-RAY TUBE

A discharge device designed to generate X-rays.

SUBCLASSES

1	PLURAL UNIT:
	This subclass is indented under the class definition.  Subject matter wherein the plurality of electric lamps or discharge devices or an electric lamp and a discharge device are structurally combined in a single device to form a single unitary device. (1) Note. This or the indented subclasses do not include the following subject matter even though such subject matter is within the subclass definition: (a) An incandescent lamp having a plurality of filaments or glowers all within the same envelope is not included in this or the indented subclasses but will be found in subclass 316 below, or in one of the subclasses specified in the search notes of that subclass; (b) Structural combinations of an incandescent lamp and a discharge device where the filament of the lamp is connected in shunt with the discharge electrodes of the discharge device. See Class 315, Electric Lamp and Discharge Devices: Systems, subclasses 46+ for this subject matter; (c) Structural combinations of an incandescent lamp and a discharge device where the lamp filament is connected in series with the discharge electrodes of the discharge device. See Class 315, Electric Lamp and Discharge Devices: Systems, subclass 49 for this subject matter; (d) Structural combinations consisting of a firing gap of a spark plug, and an intensifier gap connected in series therewith, see subclasses 123+ for this subject matter. (2) Note. In many of the devices in this and the indented subclasses the plurality of devices are enclosed within the same envelope. (3) Note. Where the subject matter includes a plurality of discharge devices which are structurally combined, to be classified in this or the indented subclasses there must not be a common electrode for the plurality of discharge devices. For example, discharge devices having a single cathode and a plurality of anodes which cooperate with the single cathode are excluded from this and the indented subclasses even though the disclosure states that the device may be used in place of a plurality of discharge device. Included in this and the indented subclasses are structural combinations of plural discharge devices and lamps or a discharge device and a lamp where there is an interelectrode connection between the electrodes of the different devices. SEE OR SEARCH THIS CLASS, SUBCLASS: 306, and the subclasses specified in the notes thereto for discharge devices which are provided with a plurality of anodes and/or cathodes. Included in subclasses 306+ are space discharge devices having a plurality of similar gaps connected in series, such as for example, a row of spaced sphere electrodes in which a discharge takes place along the length of the row. SEE OR SEARCH CLASS: 314,  Electric Lamp and Discharge Devices: Consumable Electrodes,   subclasses 7+ , for the combination of a consumable electrode discharge device (e.g., an arc lamp or similar device having means for feeding the electrodes together as they are consumed) and another type of discharge device or electric lamp. 315,  Electric Lamp and Discharge Devices: Systems,   subclasses 3+ , 32, 35+, and 64+ for the structural combination of a plurality of discharge devices, or lamps, or a discharge device and a lamp where the structural combination includes a circuit element (e.g., switch, impedance, etc.), see subclasses 3+ where one of the devices is a cathode‐ray tube, subclass 32 where the combination includes a lamp and a discharge device, subclasses 35+ where the combination includes a plurality of discharge devices, and subclasses 64+ where the combination includes a plurality of lamp filaments (multifilament lamps). In the devices in Class 315, the circuit element may be connected between electrodes of different ones of the combined devices, or to an electrode of one of the devices, or not connected to any of the combined devices but be merely mounted in the envelope, base or other part of the unitary device. For the structural combinations of incandescent lamps and discharge devices connected in circuit relation, which are classified in Class 315, see (1) Note, parts b and c, above. 378,  X‐Ray or Gamma Ray Systems or Devices,   subclasses 9 , 92 and 193+ for plural source systems or devices.

2.1	Cathode‐ray tube:
	This subclass is indented under subclass 1.  Subject matter in which one of the devices is a cathode‐ray generating device. SEE OR SEARCH THIS CLASS, SUBCLASS: 364+, for cathode ray devices, per se. SEE OR SEARCH CLASS: 315,  Electric Lamp and Discharge Devices: Systems,   subclasses 3+ for devices which include the structural combination of a plurality of cathode‐ray tubes and which have a circuit element (e.g., switch, inductance, condensers, resistances, etc.) structurally combined therewith. See especially subclasses 5.14+ for cathode‐ray tube circuits wherein a plurality of rays pass through or in a hollow distributed parameter device, such as a wave guide, cavity resonator, or coaxial line; and subclasses 5.16+, 5.27, 5.28, and 5.39+ for cathode‐ray tube system including a plurality of hollow distributed parameter devices having a cathode ray passing through or in. See subclass 9 for systems for supplying electric current and/or potential to a plurality of cathode‐ray tubes. 378,  X‐Ray or Gamma Ray Systems or Devices,   subclass 92 for the structural combination of a plurality of X‐ray tubes and a circuit element which is combined therewith.

3	Inter‐electrode connection:
	This subclass is indented under subclass 1.  Subject matter in which one electrode of one of the devices is electrically connected to an electrode of another of the devices. (1) Note. Excluded from this subclass and class are structural combinations of a discharge device and an incandescent lamp where the lamp filament is connected either in series or in shunt relation with the discharge electrodes. The excluded devices will be found in Class 315, Electric Lamp and Discharge Devices: Systems, subclasses 46+ where the filament is connected in shunt relation to the discharge electrodes and in subclass 49 where the filament is connected in series relation with the discharge electrodes. (2) Note. If the connection between the electrodes includes a circuit element such as a resistor, capacitor, inductance, switch, or the like the combination is not classified in this class but in Class 315. The devices in this subclass have a conductive connection but no more. SEE OR SEARCH CLASS: 315,  Electric Lamp and Discharge Devices: Systems,   (see (1) Note) above, and subclasses 3+ , 32+, 35+, 64+ for the structural combination of a plurality of discharge devices, or lamps, or a discharge device and a lamp where the structural combination includes a circuit element (e.g., switch, impedance, etc.), connected between electrodes of different ones of such devices. See the notes to subclass 1 for the subclasses which provide for the different types of devices.

5	Control electrode unit:
	This subclass is indented under subclass 1.  Subject matter in which one of the structurally combined devices is a discharge device with a control electrode. SEE OR SEARCH THIS CLASS, SUBCLASS: 308, and the subclasses specified in the notes thereto for other discharge devices which are provided with a control electrode.

6	Plural control electrode units:
	This subclass is indented under subclass 5.  Subject matter which includes a plurality of discharge devices each having a control electrode. SEE OR SEARCH CLASS: 315,  Electric Lamp and Discharge Devices: Systems,   subclasses 3+ and 35+ where the structural combination also includes a circuit element (e.g., switch, impedance, etc.), see subclasses 3+ where the devices are cathode‐ray tubes and subclasses 35+ for other plural discharge devices.

7	WITH EVACUATING PUMP:
	This subclass is indented under the class definition.  Subject matter where the lamp or discharge device is provided with an envelope and has an evacuating pump connected to the envelope for evacuating the envelope. (1) Note. In the devices in this subclass the evacuating pump is designed for connection to the lamp or discharge device during the use of the lamp or discharge device. Where the arrangement is only for use during the manufacturing of the lamp or discharge device see the reference to Class 226 below. SEE OR SEARCH THIS CLASS, SUBCLASS: 549+, for devices under the class definition provided with envelopes and having a getter, a gas or vapor generating means or a pressure regulating means associated therewith. SEE OR SEARCH CLASS: 53,  Package Making,   subclasses 79+ and 403+ for methods of and apparatus for gas filling and/or evacuating receptacles combined with closing including lamps and discharge devices, and see the Notes to subclass 403 for the disposition of related art. 141,  Fluent Material Handling, With Receiver or Receiver Coacting Means,   subclasses 4 , 8 and 65+ for methods of and apparatus for inducing a gas or vapor into or evacuating the envelope of an electric lamp or space discharge device. 315,  Electric Lamp and Discharge Devices: Systems,   subclasses 108+ for electric lamp or a gas or vapor type discharge device systems where the lamp or discharge device is provided with means for regulating the pressure within the envelope of the device and the system includes means to supply electrical energy to the lamp or discharge device or to control the pressure regulating means. 378,  X‐Ray or Gamma Ray Systems or Devices,   subclass 123 for X‐ray tube systems where the X‐ray tube is provided with means for controlling the pressure within the envelope of the tube. 417,  Pumps,   appropriate subclasses for miscellaneous evacuating pumps.

8	ARC AND SEPARATE INCANDESCENT BODY:
	This subclass is indented under the class definition.  Discharge devices which have a body other than an electrode, placed adjacent to the discharge space and which is designed to be heated to incandescence by the space discharge. (1) Note. The body which is designed to be heated to incandescence is not designed to be connected into the circuit in any way but is only a light emitting body. SEE OR SEARCH THIS CLASS, SUBCLASS: 305, and the subclasses specified in the notes to the definitions of that subclass for discharge devices which have an electrode designed to be heated by the discharge, including devices having cathanodes.

9	FILAMENT AND SEPARATE INCANDESCENT BODY:
	This subclass is indented under the class definition.  Devices having a filament and an additional body other than an electrode designed to be heated to incandescence by the filament. (1) Note. The body designed to be heated to incandescence is not designed to be connected in the circuit in anyway but is designed only to be a light emitting body. SEE OR SEARCH THIS CLASS, SUBCLASS: 14, for pyroelectric type electric lamps which include a body designed to be heated from a separate source such as an electric filament. The body being a second class conductor and being connected in the circuit so that when heated it will conduct electric current and be heated by the current flowing through it. 305+, and the subclasses specified in the notes thereto for discharge devices which have an electrode which is designed to be heated to incandescence by the electric space discharge between the cathode and the electrode.

10	WITH TEMPERATURE INDICATOR:
	This subclass is indented under the class definition.  Subject matter where the lamp or discharge device is provided with means to indicate the temperature of some part of the device. SEE OR SEARCH CLASS: 374,  Thermal Measuring and Testing,   subclasses 100+ for temperature measurement, per se.

11	WITH TEMPERATURE MODIFIER:
	This subclass is indented under the class definition.  Subject matter where a lamp, discharge device or an electrode therefor is provided with means or is combined with means for modifying the temperature of the device, the electrode, or some other part thereof. (1) Note. Neither this nor any of the indented subclasses provide for electric lamps including those of the discharge device type, photosensitive discharge devices nor generators of invisible radiation such as X‐ray tubes, ultraviolet ray generators in combination with a separable casing for the lamp or device which is provided with means for modifying the temperature of the lamp or device. See the class definition for the classes which provide for the excluded subject matter. (2) Note. Indented subclass 26 provides for discharge devices and lamps which are provided with an envelope formed of two spaced apart integral walls, the space between the walls being evacuated, gas filled, or otherwise containing means to modify the temperature of the lamp or discharge device. See the class definition for the classification of double wall envelopes, per se. (3) Note. Discharge devices and lamps provided only with directly heated filaments, indirectly heated cathodes or other types of thermionic cathodes, are not included in this or the indented subclasses. This and the indented subclasses provide only for lamps and discharge devices which have means in addition to the filament or cathode for modifying the temperature of the lamp or discharge device. Note that discharge devices having liquid electrodes (e.g., mercury vapor device) and electric heaters therefor are in subclass 16 and discharge devices having liquid electrodes and other types of temperature modifiers for the liquid electrode are in subclass 29. (4) Note. See the class definition for other classes which provide for the miscellaneous heat transfer apparatus such as envelopes and casings for lamps or discharge devices with temperature modifying means. (5) Note. Discharge devices and lamps having a movable electrode actuated by a thermally responsive means such as a thermostat, with or without a heating means for the thermally actuated moving means, are not classified in this and indented subclasses, but are found in subclass 151. SEE OR SEARCH THIS CLASS, SUBCLASS: 151, see (5) Note above. SEE OR SEARCH CLASS: 314,  Electric Lamp and Discharge Devices: Consumable Electrodes,   subclasses 26+ for consumable electrode discharge devices provided with temperature modifying means and the electrical systems therefor. 315,  Electric Lamp and Discharge Devices: Systems,   subclass 50 for electric lamps and discharge devices which are provided with means for modifying the temperature of at least part of the lamp or discharge device, the temperature modifying means being either combined with or forming an electrical impedance element. In subclass 50, of Class 315 will be found, for example, discharge devices which are provided with means to conduct a cooling fluid to the discharge device where the conduits for conducting the cooling fluid are arranged to form a high resistance path between a discharge device and the source of cooling fluid. See subclasses 112+ and the subclasses specified in the notes to those subclasses for electric lamp and discharge device systems wherein the lamp or discharge device is provided with means for modifying its temperature and the system includes means to supply current to the lamp or discharge device or to control the temperature modifying means.

11.5	Spark plug type:
	This subclass is indented under subclass 11.  Unitary devices known as spark plugs. (1) Note. See the glossary of this class definition, for a definition of spark plugs. In general, the spark plugs classified herein are the jump‐spark type found in the gasoline engine of an automobile. (2) Note. This subclass contains patents relating to spark plugs where the temperature modification of some part of the plug is material. If the plug is provided with gaskets or joints are of high or low heat conductivity, the patent would be included. A plug having gaskets or joints formed of particular materials would be classified in subclasses 144+ if it was not stated the materials were selected for their temperature modification properties. (3) Note. Preheating of the gas charge (before the spark jumps) by heat left in the spark plug from a previous explosion stroke cycle is not basis for classification in this subclass unless such preheating is accomplished by means which are especially provided to alter the temperature of the spark plug. SEE OR SEARCH THIS CLASS, SUBCLASS: 120, for spark plugs having means to feed a fluid, such as priming fluid or air, where there is no disclosure that the temperature of the spark plug is affected by the fluid feed. 126, for spark plugs having means to move an electrode in response to a thermal change and having no means to influence the thermal characteristics of the spark plug. SEE OR SEARCH CLASS: 174,  Electricity: Conductors and Insulators,   subclasses 15.3 and 152 for spark plug type electrical bushings (a spark plug with no sparking electrodes claimed) having temperature modifying means. See subclass 15.3 where the bushing is combined with means for feeding, circulating or distributing a temperature modifying fluid. 439,  Electrical Connectors,   subclasses 190+ and 485+ for an electrical connector, including the spark plug type, with temperature modifying means.

12	Recirculating systems:
	This subclass is indented under subclass 11.  Subject matter in which the temperature modifying means includes a closed path for circulating the temperature modifying means from the lamp or discharge device to a heat exchange means and then back to the lamp or discharge device to again modify the temperature of the lamp or discharge device. SEE OR SEARCH CLASS: 165,  Heat Exchange,   subclasses 104.11+ recirculating heat exchange system of general application.

13	Having control means for the temperature modifier:
	This subclass is indented under subclass 11.  Subject matter in which a control means is provided for controlling the operation of the temperature modifying means. (1) Note. Included in this subclass are discharge devices in casings provided with apertures which are controlled by thermostatic means so as to regulate the amount of cooling air which flows over the discharge device. If the thermostatic means controls an electric circuit which in turn controls an electric circuit which in turn controls electrical means for controlling the apertures, the patent is excluded from this class and will be found in Class 315. See the reference to class 315 below. SEE OR SEARCH CLASS: 165,  Heat Exchange,   subclasses 279+ for miscellaneous heat exchange apparatus provided with automatic control means. 236,  Automatic Temperature and Humidity Regulation,   appropriate subclasses for automatic temperature regulation, per se. 315,  Electric Lamp and Discharge Devices: Systems,   subclass 117 and the subclasses specified in the notes thereto for discharge devices and lamps which are provided with temperature modifying means and which include electrical circuit means for controlling the operation of the temperature modifying means.

14	Pyroelectric type device:
	This subclass is indented under subclass 11.  Subject matter having a glower formed of a second class conductor designed for connection into an electrical circuit, and having means for heating the glower to render it conductive. (1) Note. The devices in this subclass are mostly pyroelectric lamps. (2) Note. See "Glossary" in the class definition for a definition of second class conductor, glower, pyroelectric lamps. SEE OR SEARCH THIS CLASS, SUBCLASS: 9, for devices under class definition which include a filament and a body not designed to be connected into an electrical circuit which is heated to incandescence by the filament. 326+, for the structure of pyroelectric glowers, per se. SEE OR SEARCH CLASS: 252,  Compositions,   subclasses 500+ for pyroelectric glower compositions. 315,  Electric Lamp and Discharge Devices: Systems,   subclasses 115+ for pyroelectric lamp systems having an electric heater for the glower and circuit means for controlling or supplying electric current to the glower or the heater element, and subclass 359 for miscellaneous systems for supplying electric current to pyroelectric lamps. 338,  Electrical Resistors,   subclasses 25+ for electrical resistors whose resistance value is responsive to a change in ambient temperature.

15	Electric heater:
	This subclass is indented under subclass 11.  Subject matter in which the temperature modifier is an electric heater. (1) Note. This subclass does not include lamps or discharge devices where the only heating means for the lamp or discharge device is a light emitting filament, a directly heated or indirectly heated cathode or other thermionic cathode or where the heating means is a means for heating a gas or vapor generating material (e.g., a getter). See subclasses 549+ for the discharge devices and lamps with electric heating means for a gas or vapor generating material. SEE OR SEARCH THIS CLASS, SUBCLASS: 14, where the lamp is a pyroelectric lamp and is provided with an electric heater to heat the glower. SEE OR SEARCH CLASS: 315,  Electric Lamp and Discharge Devices: Systems,   subclasses 115+ for electric lamp and discharge device systems where the lamp or discharge device is provided with an electrical heater to modify the temperature of the lamp or discharge device and the system includes means to control or supply current to the heater or the lamp or discharge device.

16	For liquid electrode:
	This subclass is indented under subclass 15.  Subject matter in which the lamp or discharge device is provided with a liquid electrode and the electric heater is provided to heat the liquid electrode. SEE OR SEARCH THIS CLASS, SUBCLASS: 29, for other devices under subclass 11 having liquid electrode and having temperature modifying means for the liquid electrode. 163+, for other liquid electrode discharge devices. SEE OR SEARCH CLASS: 315,  Electric Lamp and Discharge Devices: Systems,   subclasses 115+ for lamp and discharge device systems where the lamp or discharge device is provided with a liquid electrode and an electric heater therefor, the system including means to control or to supply current to the heater or to the lamp or discharge device.

17	Double wall, jacket or casing for envelope:
	This subclass is indented under subclass 11.  Subject matter in which a lamp or discharge device is provided with a an integral spaced double walled envelope, and discharge devices which are provided with envelopes and in which the means for modifying the temperature of the discharge device includes a jacket or casing which encloses the envelope of the device or a portion thereof. (1) Note. Neither this nor any of the indented subclasses provide for electric lamps including those of the discharge device type, photosensitive discharge devices nor generators of invisible radiation such as X‐ray tubes, ultraviolet ray generators in combination with a separable casing for the lamp or device which is provided with means for modifying the temperature of the lamp or device. See the class definition for the classes which provide for the excluded subject matter. (2) Note. The double‐walled envelopes specified above includes only walls which are spaced apart. The double walled envelope may be provided with means for circulating a fluid between the spaced walls or the space between the walls may be evacuated, gas filled or filled with a heat insulating or transmitting material. See the class definition for the classification of double‐wall envelopes, per se. (3) Note. The jacket or casing which encloses the discharge device or lamp must have its walls spaced from the envelope of the lamp or discharge device. Where the device is provided with a sleeve with heat exchange means such as radiating fins which fit over and into contact with the envelope of the device, the device is excluded from this and the indented subclass and will be found in subclass 44 below. (4) Note. Included as separable casings and jackets are structures formed of coiled conduits which are designed to receive the discharge device and to transfer heat to or from the envelope of the discharge device. (5) Note. See the class definition for other classes which provide for the miscellaneous heat transfer apparatus such as envelopes and casings for lamps or discharge devices which are provided with temperature modifying means. SEE OR SEARCH THIS CLASS, SUBCLASS: 44, see (3) Note, above. 312, and the subclasses specified in the notes thereto for devices under the class definition which are provided with an envelope and which have a casing or jacket for the envelope. 324, and the subclasses specified in the notes thereto for devices under the class definition which do not have an envelope but which have a casing or jacket for the device. SEE OR SEARCH CLASS: 165,  Heat Exchange,   subclass 74 for a removable device to be heated or cooled projecting into a casing, and subclasses 154+ for coaxial enclosures. 215,  Bottles and Jars,   subclasses 12.1+ for receptacles of glass or other ceramic or similar materials, of the bottle, jar, or jug type, which are encased in a protective casing or jacket or having spaced walls. 220,  Receptacles,   subclasses 2.1+ for miscellaneous envelopes, casings and jackets designed for use with electric lamps, discharge devices and similar devices and subclasses 415+ for miscellaneous receptacles having double walls where the inner and outer walls are spaced apart, with or without intervening packing or insulation. 314,  Electric Lamp and Discharge Devices: Consumable Electrodes,   subclasses 26+ for discharge devices of the consumable electrode type (e.g., arc lamps) which are provided with means for modifying the temperature of a portion of the device, the temperature modifying means including a separable casing or jacket for a portion of the device.

18	For conductive envelope devices:
	This subclass is indented under subclass 17.  Subject matter in which the envelope of the lamp or discharge device is provided with an integral double wall envelope made in whole or in part of electrically conductive material, and discharge devices which are provided with envelopes formed in whole or in part of electrically conductive material and in which the casing or jacket encloses the electrically conductive portion of the envelope or a portion thereof. SEE OR SEARCH THIS CLASS, SUBCLASS: 44, for other lamps and discharge devices under subclass 11 which have a conductive envelope and which are provided with means for modifying the temperature of the envelope wall. Included in subclass 44 are discharge devices which are provided with a separable sleeve which fits about a portion of the envelope wall, the sleeve being provided with heat exchange means (e.g., radiating fins). 246+, for discharge devices which are provided with a conductive envelope portion (e.g., anode) and means to support one or more electrodes (e.g., cathode, grid) within the conductive envelope portion usually by means of the closure for the conductive envelope portion. 317+, for devices under the class definition having envelopes or a part thereof made of conductive material. SEE OR SEARCH CLASS: 220,  Receptacles,   subclass 2.3 for envelopes for discharge devices and lamps which are made in whole or in part of conductive material.

19	With plural electrode temperature modifying:
	This subclass is indented under subclass 18.  Subject matter wherein the lamp or discharge device has a plurality of electrodes and means are provided for modifying the temperature of a plurality of the electrodes. SEE OR SEARCH THIS CLASS, SUBCLASS: 23, for other lamps and discharge devices which are provided with a plurality of electrodes, a double wall jacket or casing for the envelope and means for circulating a fluid within the double wall envelope, casing, or jacket to modify the temperature of a plurality of the electrodes. 28, for other lamps and discharge devices which are provided with a plurality of electrodes, a double wall envelope or a casing or jacket for the envelope and means for modifying the temperature of a plurality of the electrodes.

20	With internal temperature modifying baffle:
	This subclass is indented under subclass 18.  Subject matter where the lamp or discharge device includes a temperature modifying baffle structure which extends across or into the envelope. (1) Note. In some of the devices in this subclass the baffle comprises a re‐entrant portion of the envelope wall and the temperature modifying fluid may enter the re‐entrant portion. In other of the devices, a heat transfer device, such as a radiator member for containing a heat transfer fluid, is enclosed within the envelope of the device. SEE OR SEARCH THIS CLASS, SUBCLASS: 33, for other lamps and discharge devices which do not have an enclosing casing or jacket and which have an internal temperature modifying baffle. 34, for lamps and discharge devices which do not have an enclosing casing or jacket where the envelope is provided with a condensing chamber or surface.

21	Cylindrical electrode type envelope:
	This subclass is indented under subclass 18.  Subject matter in which the conductive envelope portion of the lamp or discharge device is cylindrical in form and is designed for use as one of the electrodes of the device. (1) Note. Many of the devices in this subclass are discharge devices such as are used as the transmitting tube in radio transmitting systems. SEE OR SEARCH THIS CLASS, SUBCLASS: 246+, for discharge devices which are provided with a cylindrical conductive envelope portion (e.g., anode) and means to support one or more electrodes (e.g., cathode, grid) within the conductive envelope portion usually by means of the closure for the cylindrical envelope portion. 317+, and the subclasses specified in the notes thereto for other lamps and discharge devices under the class definition in which an electrode forms a portion of the envelope.

22	Fluid circulation type:
	This subclass is indented under subclass 17.  Subject matter in which the structure is designed so that a temperature modifying fluid may be circulated in the space between the envelope and the jacket or casing or between the walls of the double walled envelope. SEE OR SEARCH THIS CLASS, SUBCLASS: 18+, where the envelope of the lamp or discharge device is made in whole or part of conductive material. 36, for discharge devices and lamps which are not provided with an envelope but which includes a jacket or casing for the discharge device or lamp or a part thereof, and means to apply a temperature modifying fluid to the lamp or discharge device. Some of the devices in subclass 36 are open‐air arc lamps with casing means around portions of the lamp to direct a cooling fluid into contact with a portion of the lamp.

23	Plural electrode temperature modifying:
	This subclass is indented under subclass 22.  Subject matter where the lamp or discharge device has a plurality of electrodes and means are provided for modifying the temperature of a plurality of the electrodes. SEE OR SEARCH THIS CLASS, SUBCLASS: 19, where the lamp or discharge device is provided with an envelope which is made in whole or part of a conductive material. 28, for other lamps and discharge devices which are provided with a plurality of electrodes, a double wall envelope or a casing or jacket for the envelope and means for modifying the temperature of a plurality of the electrodes.

24	Flow directing means in casing:
	This subclass is indented under subclass 22.  Subject matter having means (e.g., baffles) within the casing or jacket which encloses the envelope or between the walls of the double‐walled envelope for directing the flow of the temperature modifying fluid as it flows through the casing, jacket or doubled envelope.

25	Sealed casing for envelope:
	This subclass is indented under subclass 17.  Devices in which the space between the double wall envelopes or between the envelope and the casing or jacket is sealed off from the atmosphere and from the space within the envelope of the lamp or discharge device. (1) Note. This subclass includes electric lamps whether of the discharge device type or not, photosensitive discharge devices, generators of invisible ray energy (e.g., X‐ray tubes, ultraviolet lamps, etc.) only when the casing or jacket is integrally united with the envelope of the device. See (1) Note to the definition of subclass 11 with respect to the classification of such subject matter where the casing or jacket is not integrally united. SEE OR SEARCH THIS CLASS, SUBCLASS: 27, for other discharge devices and lamps which are provided with a double wall envelope or which have a jacket or casing for the envelope of the device, the space between the envelope walls or between the casing or jacket and the envelope containing a heat conserving or heat insulating material. 312, and the subclasses specified in the notes thereto, for miscellaneous and discharge devices which are provided with an envelope and a casing or jacket for the envelope. 317+, for miscellaneous lamps and discharge devices which are provided with a double‐wall envelope where the heat transmitting properties of the double wall envelope are not involved.

26	Integral double wall type of envelope:
	This subclass is indented under subclass 25.  Subject matter in which the lamp or discharge device is provided with a double wall envelope, the envelope walls being formed as a unitary, integral body. (1) Note. Included in this subclass are lamps and discharge devices which are provided with a double‐walled envelope or an envelope and a casing where the space between the double walls or between the envelope and casing is evacuated or filled with a gas or vapor. SEE OR SEARCH THIS CLASS, SUBCLASS: 317+, for miscellaneous lamps and discharge devices which are provided with a double walled envelope where the heat transmitting properties of the double‐wall envelope are not involved. SEE OR SEARCH CLASS: 215,  Bottles and Jars,   subclass 13.1 for receptacles of the bottle or jar type made of glass or other ceramic or similar materials and having spaced walls, with the interwall space evacuated or filled with a gas or vapor for heat insulation purposes. 220,  Receptacles,   subclasses 2.1+ for double walled envelopes designed for use with lamps and discharge devices.

27	Heat conserving or insulating type:
	This subclass is indented under subclass 17.  Subject matter in which the space between the casing or jacket which encloses the envelope or the space between the double‐walled envelope, includes means for preventing the flow of heat to or from the device. SEE OR SEARCH THIS CLASS, SUBCLASS: 25+, where the space between the double walls or between the envelope and the casing or jacket is sealed off from the atmosphere and from the space within the envelope of the device. The sealed off space may be evacuated or filled with a gas or vapor. Note indented subclass 26 for discharge devices and lamps provided with an integral double‐wall envelope. SEE OR SEARCH CLASS: 215,  Bottles and Jars,   subclass 13.1 for receptacles of the bottle or jar type made of glass or other ceramic or similar material and having spaced walls with the interwall space containing a heat insulating means. 220,  Receptacles,   subclasses 2.1+ for double‐walled envelopes designed for use for lamps and discharge devices, subclasses 415+ for miscellaneous receptacles having double‐walls where the inner and outer walls are spaced apart and the intervening space contains a heat insulating material.

28	Plural electrode temperature modifying:
	This subclass is indented under subclass 17.  Subject matter where the lamp or discharge device is provided with a plurality of electrodes and means are provided for modifying the temperature of a plurality of the electrodes. SEE OR SEARCH THIS CLASS, SUBCLASS: 19, where the envelope of the lamp or discharge device is made in whole or part of electrical conductive material. 23, where the structure includes means to circulate a fluid between the walls of a double walled envelope of a lamp or discharge device or between the envelope and the enclosing casing or jacket of a discharge device.

29	For liquid electrode:
	This subclass is indented under subclass 11.  Devices having a liquid electrode and having means for modifying the temperature of the liquid electrode. SEE OR SEARCH THIS CLASS, SUBCLASS: 16, where the means for modifying the temperature of the liquid electrode is an electric heater. 163+, for liquid electrode discharge devices, per se.

30	Hollow electrode or lead:
	This subclass is indented under subclass 11.  Devices where the lamp or discharge device is provided with a hollow electrode or a hollow electrode lead conductor, means being provided to modify the temperature of the hollow portion of the electrode or the electrode lead. (1) Note. In many of the devices in this subclass a fluid is circulated into the hollow electrode or electrode lead. See indented subclasses 31 and 32 where the hollow electrode or lead constitutes a closed path so that fluid may be circulated through the electrode or lead.

31	Tubular coil electrode:
	This subclass is indented under subclass 30.  Devices in which the electrode is in the form of a fluid conduit which is in the form of a coil. SEE OR SEARCH CLASS: 138,  Pipes and Tubular Conduits,   subclasses 100 through 178for pipe structure, per se. 165,  Heat Exchange,   appropriate subclasses for a heat exchanger, per se.

32	Closed duct type (e.g., for liquid):
	This subclass is indented under subclass 30.  Devices in which the hollow electrode or lead is provided with a closed conduit designed for the passage of a temperature modifying fluid therethrough. (1) Note. In many of the devices in this subclass the electrode or lead is provided with two coaxial tubes one within the other and the fluid flows in one direction through the inner tube and in the opposite direction between the walls of the inner and outer tubes, but this subclass is not limited to such devices. SEE OR SEARCH THIS CLASS, SUBCLASS: 31, where the electrode is in the form of a conduit which is in the form of a coil. 35+, and the subclasses specified in the notes thereto for devices under subclass 11 in which the temperature modifying means includes means for applying a temperature modifying fluid (e.g., a cooling fluid) to some part of the device, which part may be an electrode or lead.

33	Envelope with internal temperature modifying baffle:
	This subclass is indented under subclass 11.  Devices having an envelope and having a temperature modifying baffle entending across or into the interior of the envelope. SEE OR SEARCH THIS CLASS, SUBCLASS: 20, where the envelope is made in whole or part of conductive material and has a double‐wall or is enclosed within a casing or jacket.

34	Envelope with condensing chamber or surface:
	This subclass is indented under subclass 11.  Devices where the device is provided with an envelope, the envelope including a chamber having a surface which has a large heat dissipating surface for condensing vapors generated during the operation of the device. (1) Note. Most of the devices in this subclass are mercury vapor discharge devices and the condensing surface is designed to condense the mercury vapor into its liquid state. (2) Note. Included in this subclass are all discharge devices where the envelope is provided with any portion such as an enlarged portion or a portion located in a place which remains relatively cool during the operation of the device, where the purpose of such portion is to condense vapors and to change the vapors to either their liquid or solid state. (3) Note. See the classification of envelopes designed for use with lamps and discharge devices which are provided with temperature modifying means. See the class definition for the classification of envelopes, per se, designed for use with electric lamps and discharge devices. SEE OR SEARCH THIS CLASS, SUBCLASS: 17+, where the device is provided with either a double‐wall or a jacket or casing for the envelope. Note especially indented subclass 20 where the device is provided with an internal temperature modifying baffle and subclasses 22+, where means are provided for circulating a fluid in contact with the envelope wall. 33, for devices within the definition of subclass 11 where the envelope of a device is provided with an internal temperature modifying baffle. 35, for discharge devices and lamps which are provided with envelopes with tubular passageways or conduits formed in the envelope and passing through the lamp near the filament or other heated portion of the device so that the conduit becomes hot and the heated air rises to draw cold air in at the bottom of the conduit.

35	Using liquids or fluid flow directing means:
	This subclass is indented under subclass 11.  Subject matter wherein the temperature of the discharge device or lamp is modified by applying a heat exchange liquid to the discharge device or lamp or where the structure includes means to direct the flow of the temperature modifying fluid. (1) Note. Subclasses 35+, includes discharge devices and lamps which do not have envelopes and which are provided with means for contacting a portion of the device with a heat exchange fluid or liquid. The fluid or liquid containing means may be arranged so that the fluid or liquid may be circulated. Also included are lamps and discharge devices with envelopes with tubular passage ways or conduits formed in the envelope and passing through the lamp near the filament, or other heated portion of the device so that the conduit becomes hot and the heated air rises to draw cold air in at the bottom of the conduit. SEE OR SEARCH THIS CLASS, SUBCLASS: 12, where the apparatus includes a recirculating system with a heat exchanger in it so that the temperature modifying fluid is circulated from the lamp or discharge device to the heat exchanger then back again to the lamp or discharge device. 17+, where the lamp or discharge device is provided either with a spaced double‐walled envelope or with an envelope and a casing or jacket around the envelope, the structure including means to modify the temperature of the lamp or discharge device. See especially subclasses 22+, where means are provided to circulate a temperature modifying fluid in the space between the double‐walls of the envelope or between the envelope and the casing or jacket. 29, where the lamp or discharge device is provided with a liquid electrode. 30+, where the lamp or discharge device is provided with a hollow electrode or a hollow electrode lead conductor and means are provided to modify the temperature of the hollow portion of the electrode or electrode lead. 33, where lamp or discharge device is provided with an envelope and an internal temperature modifying baffle which extends across or into the envelope. 34, where the envelope is provided with either a condensing chamber or condensing surface. SEE OR SEARCH CLASS: 314,  Electric Lamp and Discharge Devices: Consumable Electrodes,   subclasses 26+ for discharge devices of the consumable electrode type (e.g., arc lamps) which are provided with means for directing the flow of a temperature modifying medium over a portion of the device. The flow directing means may include a casing or jacket for a portion of the device. See indented subclass 29 where the temperature of the device is modified by means of a heat exchange liquid.

36	Jacket or casing:
	This subclass is indented under subclass 35.  Devices in which the means for applying the temperature modifying fluid includes a jacket or casing which surrounds at least a part of the lamp or discharge device or which is associated with the means for applying the temperature modifying fluid so as to direct the temperature modifying fluid upon some part of the lamp or discharge device. SEE OR SEARCH THIS CLASS, SUBCLASS: 17+, where the lamp or discharge device is provided either with a spaced double walled envelope or with an envelope that has a casing or jacket which surrounds at least a portion of the envelope. 324, for miscellaneous electric lamps and discharge devices which do not have envelopes but which are provided with casings and jackets. SEE OR SEARCH CLASS: 165,  Heat Exchange,   subclass 74 for a removable device projecting into a chamber containing a heat exchanger fluid. 314,  Electric Lamp and Discharge Devices: Consumable Electrodes,   subclasses 26+ for discharge devices of the consumable electrode type (e.g., arc lamps) which are provided with a jacket or casing for directing the flow of a temperature modifying medium over a portion of the device.

37	For filament or heated cathode:
	This subclass is indented under subclass 11.  Devices which are provided with a filament, a directly heated cathode or an indirectly heated cathode and which include means to modify the temperature of the filament or cathode. (1) Note. The structure must include more than a filament, a directly heated cathode or an indirectly heated cathode. For example, included in this and the indented subclass are devices in which a heat conserving shield is placed about the cathode to conserve the heat of the cathode and devices which have means to conduct heat from a portion of the cathode so as to reduce the temperature of the cathode portion. SEE OR SEARCH THIS CLASS, SUBCLASS: 39+, for other devices under subclass 11 which are provided with a cathode which may be a thermionic cathode other than a directly or indirectly heated cathode and which includes means to modify the temperature of the cathode. 337+, for the structures of indirectly heated cathodes, per se. 341+, for the structure of filaments and directly heated cathodes. 346, for the structure of thermionic cathodes.

38	Hollow shield around filament or cathode:
	This subclass is indented under subclass 37.  Devices in which the temperature modifying means is a hollow shield which surrounds at least a portion of the filament or heated cathode.

39	For electrode within an envelope:
	This subclass is indented under subclass 11.  Devices which are provided with an envelope and an electrode within the envelope, heat transfer means being provided to modify the temperature of the electrode. (1) Note. The heat transfer means may be mounted upon or form a part of the electrode. For example, an electrode may be formed with a heat indicating surface. SEE OR SEARCH THIS CLASS, SUBCLASS: 16, and 29, where the electrode is a liquid electrode. See subclass 16 where an electric heater is provided for the liquid electrode. 23, and 28, where the device is either provided with a double spaced wall envelope or is provided with an envelope and a jacket or casing which surrounds at least a portion of the envelope and means are provided to modify the temperature of a plurality of electrodes within the envelope. See subclass 23, where the structure includes means to circulate a heat transfer fluid between the envelope walls or between the envelope and the casing or jacket. 28, see the reference to subclass 23 above. 29, see the reference to subclass 16 above. 30+, where the electrode or the electrode lead is hollow and means are provided to modify the temperature of the hollow portion of the electrode or lead. 37+, where the electrode which has its temperature modified is either a filament or a thermionic cathode. 42, for devices under subclass 11 which are provided with an envelope and an electrode lead‐in conductor or an electrode support, the electrode lead‐in or the electrode lead‐in support having heat transfer means mounted thereon or including means to modify the flow of heat along the electrode lead‐in or support. Subclass 42 also provides for devices under subclass 11, which are provided with an envelope and which have the heat transfer means mounted upon a lead‐in wire exterior to the envelope of the device. 43, for devices under subclass 11 which are provided with an envelope and which have temperature modifying means to protect the lead‐in‐seal or the stem of the envelope from excessive temperatures. 44, for discharge devices under subclass 11 which have the envelope formed of conductive material, the conductive material being designed for use as an electrode, heat transfer means being arranged to modify the temperature of the conductive envelope wall. SEE OR SEARCH CLASS: 378,  X‐Ray or Gamma Ray Systems or Devices,   subclasses 127+ for X‐ray tubes provided with movable targets, usually rotatable, so that the temperature of the target may be maintained cool by moving the target and changing the area exposed to the electron beam during the operation of the device.

40	Radiating type surface:
	This subclass is indented under subclass 39.  Devices in which the temperature modifier comprises a radiating surface adapted to transmit or receive radiant heat. SEE OR SEARCH THIS CLASS, SUBCLASS: 45, for other devices under subclass 11 in which the temperature modifying means is a radiating surface adapted to transmit or receive radiant heat. SEE OR SEARCH CLASS: 165,  Heat Exchange,   subclass 133 for a heat exchanger with a coated, roughened or polished surface, and subclasses 177+ for a tubular structure with heat transfer means.

41	Material, roughened surface:
	This subclass is indented under subclass 40.  Devices in which the radiating surface is either composed of a material or is coated with a material which is designed to readily radiate heat or in which the radiating surface is roughened to facilitate the radiation.

42	Mounted on lead‐in or electrode support:
	This subclass is indented under subclass 11.  Devices which are provided with an envelope and electrode within the envelope and a lead‐in conductor or electrode support for the electrode, the device having either a heat transfer means mounted upon the lead‐in or electrode support or the lead‐in or the electrode support including means to modify the flow of heat along the lead‐in or support. (1) Note. The heat exchange means may be mounted upon the lead‐in conductor exteriorly of the envelope. SEE OR SEARCH THIS CLASS, SUBCLASS: 30+, where the electrode lead‐in conductor is hollow (e.g., is provided with a conduit) and means are provided to modify the temperature of the hollow portion of the lead‐in. 39+, for devices under subclass 11 which have a heat transfer means mounted upon or forming a part of an electrode within the envelope of the device. 43, for devices under subclass 11 which are provided with means to protect the lead‐in‐seal or stem of the envelope from excessive temperatures.

43	For lead‐in‐seal or stem protection:
	This subclass is indented under subclass 11.  Devices in which the device is provided with an envelope and an electrode lead‐in‐seal or a stem and temperature modifying means are provided for protecting the lead‐in‐seal or the stem of the envelope from excessive temperatures. SEE OR SEARCH THIS CLASS, SUBCLASS: 42, where the device includes a heat transfer means mounted upon the lead‐in conductor or electrode support or where the lead‐in conductor or support is formed so as to modify the flow of heat along the lead‐in conductor or support.

44	For envelope wall:
	This subclass is indented under subclass 11.  Devices which are provided with an envelope and where the temperature modifier is designed to modify the temperature of the envelope wall or some portion thereof. SEE OR SEARCH THIS CLASS, SUBCLASS: 16, and 29, for devices which have a liquid electrode in contact with the envelope wall and which are provided with means to modify the temperature of the liquid electrode. See subclass 16 where the temperature modifier is an electric heater. 17+, where the device is provided with a spaced double wall envelope or is provided with a casing or jacket for the envelope, the structure including means to modify the temperature of the envelope wall. 29, see the reference to subclass 16 above. 34, where the envelope is provided with a chamber or surface for condensing vapors generated within the envelope. 35, where the envelope wall has its temperature modified by using liquids or where the temperature modifying means includes means for directing the flow of the temperature modifying fluid. 42, where the device is provided with a temperature modifying means mounted on or forming a part of the lead‐in conductor or electrode support so as to prevent the transmission of heat to the envelope from the electrodes. 43, where the envelope is provided with means for protecting the lead‐in seal or stem of the envelope from excessive temperatures.

45	Radiating type surface:
	This subclass is indented under subclass 11.  Devices in which the temperature modifier comprises a radiating surface adapted to transmit or receive radiant heat. SEE OR SEARCH THIS CLASS, SUBCLASS: 40+, where an electrode within an envelope is provided with a radiating surface.

46	Having heat conducting path:
	This subclass is indented under subclass 11.  Devices in which the temperature modifier is a means for conducting heat. (1) Note. Included in this subclass are devices which have a portion made of a large size or of a special material so that the heat will be conducted from a place which it is desired to keep cool to a place where the heat will be dissipated. SEE OR SEARCH CLASS: 165,  Heat Exchange,   subclasses 177+ for a tubular structure with attached heat transmitter.

47	Heat conserving or insulating type:
	This subclass is indented under subclass 11.  Devices which include means for preventing the flow of heat to or from the device. SEE OR SEARCH THIS CLASS, SUBCLASS: 25+, and 27, for devices under subclass 11 where the device is provided with a spaced double wall envelope, or where the device is provided with an envelope and a casing or jacket for the envelope, see subclasses 25+ where the space between the double walls or between the envelope and the casing or jacket is sealed and either evacuated or filled with a gas or vapor (e.g., for heat insulation), and see subclass 27 where the space between the double walls or between the envelope and casing contains other heat insulating means. SEE OR SEARCH CLASS: 220,  Receptacles,   appropriate subclasses for miscellaneous receptacles provided with heat insulating means, see especially subclasses 2.1+ for envelopes and casings designed for use with lamps and discharge devices, and subclasses 400+ and 415+ for miscellaneous receptacles provided with linings. 252,  Compositions,   subclass 62 for miscellaneous heat insulating compositions.

48	WITH HANDLE:
	This subclass is indented under the class definition.  Devices which are provided with a handle. (1) Note. This subclass excludes electric lamps including those of the discharge device type where the handle is separable from the electric lamp. For the excluded electric lamps, see Class 362, Illumination, appropriate subclasses, see especially subclasses 190+ for portable self contained illuminating devices which include a casing or handle for the lamp and means to supply the lamp with electricity (e.g., flashlights), subclasses 399+, and subclasses 382+ for miscellaneous light supports including separable handles for electric lamps. (2) Note. Among the devices included in this subclass are spark gaps mounted on handles such as are used to ignite gas burners. SEE OR SEARCH THIS CLASS, SUBCLASS: 49, for devices under the class definition combined with a support or a detachable electrical connector for the device. SEE OR SEARCH CLASS: 219,  Electric Heating,   appropriate subclasses, for arc welding electrode holders in which a handle supports a single electrode. Where the handle supports two or more electrodes and the device is not structurally limited to use in electric welding or heating, classification is in Class 313. 315,  Electric Lamp and Discharge Devices: Systems,   subclass 33 for portable self contained devices which include a source of energy, a discharge device of the arc, spark, gas or vapor type (other than a lamp), and the system for connecting the source of energy to the discharge device. 362,  Illumination,   see (1) Note, above. 607,  Surgery: Light, Thermal, and Electrical Application,   subclass 88 for electric lamps which are limited by claimed structure to use for therapeutic purposes which are provided with a handle and subclass 150 for discharge devices which are designed to transmit high frequency electric current into the human body which are provided with a handle. The devices in this subclass sometimes include an envelope with a confined gas or vapor, an electrode within the envelope and a handle for the device, the human body being used as the other electrode in the use of the device.

49	WITH DETACHABLE ELECTRICAL CONNECTOR OR SUPPORT:
	This subclass is indented under the class definition.  Subject matter where the lamp or discharge device is provided with a support or has combined therewith a detachable electrical connector. (1) Note. This subclass excludes electric lamps including those of the discharge device type, generators of invisible rays (e.g., X‐ray tubes, ultraviolet ray generators) in combination with a separable support for the device. See the class definition for the excluded subject matter. (2) Note. See the class definition of this class (Class 313) for the location of a distinct electrical connector and for line notes distinguishing this class and Class 439, Electrical Connectors. SEE OR SEARCH CLASS: 174,  Electricity: Conductors and Insulators,   subclass 138 for insulating supports for elongated tubular lamps. Also, see the reference to Class 248, subclass 50, below. 248,  Supports,   appropriate subclasses for miscellaneous supports. Note especially subclass 50 for supports designed to support elongated tubing such as gas or vapor lamps (see the reference to Class 174, above), and subclasses 500+ for the combination of a lamp or discharge device envelope and a support therefor (e.g., a socket) with where no electrical features are claimed. 439,  Electrical Connectors,   subclasses 296+ for an electrical coupling part with coupling movement actuating means or retaining means in addition to the contact thereof; and subclasses 527+ for a connector having mounting or supporting means. Class 439 includes the combination of a specific electrical connector with a broadly recited electric lamp. See (2) above.

50	Resilient or vibration damping:
	This subclass is indented under subclass 49.  Subject matter in which a support is designed to reduce the transmission of vibrations from and/or to the supported lamp or discharge device and subject matter under subclass 49 in which the support is resilient. (1) Note. The support may be a detachable electric connector (e.g., socket structure). SEE OR SEARCH CLASS: 188,  Brakes,   subclasses 378+ for devices having significant mass, which are attached to articles for damping the vibrations by inertia; and subclass 381 for devices damping vibrations by friction. 248,  Supports,   subclasses 560+ for resilient supports. 362,  Illumination,   subclasses 306 and 390, for illuminating devices which include a resilient light support.

51	Electrical connector:
	This subclass is indented under subclass 49.  Subject matter in which the support is detachable and includes an electrical connector for the lamp or discharge device, and lamps and discharge device which have combined therewith a detachable electrical connector. (1) Note. See the class definition for the classification of lamps including discharge devices, lamps, generators of invisible ray energy (e.g., X‐ray tubes, ultraviolet ray generators), in combination with a detachable support which may include an electrical connector for the device. See the class definition for the classification of detachable electrical connectors, per se, and the line between this class and Class 439, Electrical Connectors. SEE OR SEARCH CLASS: 248,  Supports,   subclasses 500+ for hold‐down devices of general application. 439,  Electrical Connectors,   subclasses 296+ especially subclasses 357+ for the combination of an electrical connector with the envelope of a lamp, including a resilient finger for holding that device to a mating electrical connector.

52	CONVERTIBLE:
	This subclass is indented under the class definition.  Devices which are convertible from one type of device to another type of device. (1) Note. Many discharge devices may be considered to be convertible from one type of discharge device to another type of discharge device simply by not using some of the electrodes of the discharge device. For example the usual triode may be used as a half‐way rectifier by not connecting the grid in any circuit. In the device in this subclass some means must be provided which is limited to use in converting the device from one type of device to another type of device. An example of the subject matter in this subclass is an incandescent lamp which has the lead wires coated with electron emissive material so that when the filament fails a glow discharge may take place between the coated lead wires thus converting the incandescent lamp to a discharge device type lamp. Note that where the converting means is an electric switch or other circuit element such as an impedance, the device is excluded from this class and will be found in Class 315, subclasses 32+. Also excluded from this subclass are incandescent lamps having plural filaments, such as a high resistance filament and a low resistance filament, which may be converted from one type of incandescent lamp to another merely by connecting one filament or the other in the circuit. (2) Note. See the class definition for the classification of lightning arresters of the arc or spark type which are designed to have the electrodes brought into contact with each other upon prolonged use of the device thereby establishing a conductive path through the device. SEE OR SEARCH THIS CLASS, SUBCLASS: 1+, for plural unit devices under the class definition, that is, devices which include in structural combination a plurality of discharge devices, a plurality of lamps other than mere multiple filament lamps, or a lamp and discharge device. 236, for devices under the class definition which are provided with a spare or extra electrode which is not used until one of the electrodes fails to operate properly when the spare or extra electrode is used to replace the defective electrode. SEE OR SEARCH CLASS: 315,  Electric Lamp and Discharge Devices: Systems,   see (1) Note above.

53	FLAME OR EXPLOSION TYPE:
	This subclass is indented under the class definition.  Discharge devices in which a flame provides an ionized path for the discharge. SEE OR SEARCH CLASS: 96,  Gas Separation: Apparatus,   subclasses 15+ for apparatus for smoke precipitation of the electrostatic type having electrodes between which the combustion products (e.g., smoke) are passed and which attract particles in the combustion products by means of electrostatic fields. 123,  Internal‐Combustion Engines,   subclass 594 for high tension ignition systems for internal combustion engines, which include a jump type spark gap igniter operating within a cylinder. 361,  Electricity: Electrical Systems and Devices,   subclasses 247+ for electrical devices for igniting combustible material which include spark or arc electrodes and means to bring the electrodes into contact with the combustible material. 431,  Combustion,   subclass 25 for a burner control circuit utilizing the current rectifying effect of a flame and subclasses 78+ for a burner controlled by an electric control circuit that senses flame.

54	WITH RADIOACTIVE MATERIAL:
	This subclass is indented under the class definition.  Devices which are provided with a radioactive material, the radioactive properties of the material being utilized in the operation of the device. (1) Note. In the patents in this subclass the radioactive property of the material must have some significance in the operation of the device. The mere use of a radioactive substance such as thorium on or in a cathode to render it electron emissive, the use of uranium stained glass, or other such uses of radioactive materials where the radioactive properties of the material are not involved in the operation of the device is not considered sufficient to cause classification of the device in this subclass. SEE OR SEARCH CLASS: 250,  Radiant Energy,   subclasses 381 and 382 for an invisible radiant energy responsive gas discharge device having a radioactive gas, a gas borne radioactive material or a radioactive source within the device to ionize the gas of the device. 252,  Compositions,   subclasses 625+ for radioactive compositions, per se.

62	CYCLOTRONS:
	This subclass is indented under the class definition.  Discharge devices provided with magnetic means for confining the path of the particles of the space discharge into a circular path and having means for accelerating the particles tangentially of the circular path. SEE OR SEARCH THIS CLASS, SUBCLASS: 153+, for other devices under the class definition which have a magnetic device associated therewith. 359.1+, for discharge devices including means to accelerate positive or negative ions. 421+, for cathode‐ray tubes with means to deflect a beam of electrons. 441+, for cathode‐ray tubes including means to accelerate a focus or beam of electrons. SEE OR SEARCH CLASS: 315,  Electric Lamp and Discharge Devices: Systems,   subclass 502 for a cyclotron. 376,  Induced Nuclear Reactions: Processes, Systems, and Elements,   appropriate subclasses for nuclear reactions and nuclear reactors.

93	GEIGER‐MUELLER TYPE:
	This subclass is indented under the class definition.  Devices which are provided with means responsive to invisible radiant energy other than ultraviolet rays or heat rays or radio waves, for altering the operation of the device. (1) Note. Such rays may be protons, alpha particles, X‐rays, gamma rays, cosmic rays or similar ray energy. (2) Note. Many discharge devices having an envelope and a confined gas or vapor atmosphere may be used as Geiger‐Mueller counter tubes. This subclass is limited to devices which include some structure which is especially provided because the device is responsive to the invisible ray energy and to discharge devices which are claimed as being Geiger‐Mueller counter tubes. For other types of gas or vapor discharge devices see subclasses 182+, and the subclasses specified in the notes thereto. SEE OR SEARCH THIS CLASS, SUBCLASS: 54, for devices within the class definition which include a radioactive material. 103+, for devices within the class definition having an electrode which is secondarily emissive, i.e., which emits secondary electrons when bombarded by primary electrons from another source. 523+, for photosensitive devices within the class definition. Especially see indented subclass 539 for those which are designed to be responsive to radiant energy, (ultraviolet or heat rays or visible light) of particular wave lengths. 539, see reference to subclasses 523+, above. 567, see (2) note, above.

103	Secondary emitter type (e.g., electron multiplier):
	This subclass is indented under the class definition.  Discharge devices having a secondary emissive electrode. (1) Note. The devices in this subclass are also known as "electron multipliers". SEE OR SEARCH THIS CLASS, SUBCLASS: 106, for devices under the class definition provided with means to prevent secondary emission from some part of the device. 346, and the subclasses specified in the notes thereto, for secondary emissive electrodes, per se. 377, 387 and 399, for cathode‐ray tubes with a secondary emissive electrode. 532+, where the discharge device includes a photosensitive electrode in addition to the secondary emissive electrode. SEE OR SEARCH CLASS: 315,  Electric Lamp and Discharge Devices: Systems,   subclass 39.63 for discharge devices having an electrode formed so as to provide a structure having distributed inductance and capacitance and operable in a magnetic field (e.g., magnetrons), the discharge device being provided with a secondary emissive electrode. 327,  Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 572+ for miscellaneous secondary emissive circuits. 329,  Demodulators,   appropriate subclasses for demodulators or detectors generally with secondary emission. 330,  Amplifiers,   subclass 42 for amplifiers having a secondary emitter discharge device. 331,  Oscillators,   subclass 89 for oscillator systems utilizing a magnetron type tube having a secondary electron emissive electrode, and subclass 133 for negative resistance oscillators utilizing a tube of the secondary electron emissive type.

104	Plural secondary emissive electrodes:
	This subclass is indented under subclass 103.  Discharge devices having a plurality of secondarily emissive electrodes. SEE OR SEARCH THIS CLASS, SUBCLASS: 306+, and the subclasses specified in the notes thereto for other discharge devices which have a plurality of cathodes.

105	Three or more:
	This subclass is indented under subclass 104.  Discharge devices having three or more secondarily emissive electrodes.

106	SECONDARY EMISSION PREVENTION:
	This subclass is indented under the class definition.  Devices provided with means to prevent the emission of secondary electrons from some part of the device. (1) Note. Discharge devices which have one or more control electrodes and in which the only means provided to suppress the secondary emissive is that one or more of the control electrodes may be used as a secondary emissive suppressing electrode are not included in this or the indented subclass but will be found in subclasses 293+, or one of the subclasses specified in the notes thereto.

107	Nonemissive material:
	This subclass is indented under subclass 106.  Devices in which the secondary emission suppression is secured by the use of a nonelectron emissive material. (1) Note. In the devices in this subclass the part which is to be nonemissive may be made of a nonemissive material or coated with a nonemissive material. (2) Note. See the class definition for the classification of electrodes where no structure of the electrode is involved other than composition of the materials used to form the electrodes, coated electrodes which involve no more structure than a base with one or more coatings thereon, and for the processes of making or coating electrodes. SEE OR SEARCH THIS CLASS, SUBCLASS: 353, for electrodes, per se, which are made of two or more portions or which have a coating upon a portion of the electrode, one portion of the electrode being a nondischarge sustaining portion. 355, and the subclasses specified in the notes thereto for coated electrodes. SEE OR SEARCH CLASS: 252,  Compositions,   subclasses 500+ , and the subclasses specified in the notes thereto for materials and compositions for discharge device electrodes.

107.5	VARIABLE WIDTH ELECTRON STREAM (E.G., MAGIC EYE):
	This subclass is indented under the class definition.  Discharge devices provided with means between the cathode and anode to change the width of the electron stream between the anode and the cathode. (1) Note. Included in this subclass are discharge devices of the so‐called "magic eye" type which have an annular anode coated with fluorescent material surrounding an emissive central cathode and a control electrode for varying the width of the discharge between the cathode and anode so that as the potential of the control electrode varies the width of the nonluminous portion of the anode varies. SEE OR SEARCH THIS CLASS, SUBCLASS: 293+, and the subclasses specified in the notes thereto, for other discharge devices which have a control grid or other apertured electrode interposed between the cathode and anode, see especially indented subclass 299 where the discharge device is provided with a plurality of control electrodes with the apertures in the different electrodes in alignment (e.g., beam power type tubes). 364+, for cathode‐ray tubes provided with means to focus the electrons into a restricted beam and with means for deflecting the beam over the surface of a target. See especially indented subclasses 461+ where the target is a fluorescent or phosphorescent screen. 483+, for other discharge devices provided with fluorescent material.

110	WITH OPTICAL DEVICE OR SPECIAL RAY TRANSMISSIVE ENVELOPE:
	This subclass is indented under the class definition.  Devices which have an optical device structurally combined with the device so that the optical device and the lamp or discharge device constitutes a single integral device and devices under the class definition which are provided with an envelope which is designed to be especially transparent to particular wave lengths of radiant energy. (1) Note. Optical devices as defined in the subclass definition include lenses, polarizers, reflectors, light diffusers, light valves, light obscuring means or any other means designed to alter the transmission of light rays in any manner. (2) Note. See the class definition for the classification of lamps and discharge devices which are combined with a separable casing, jacket, shield, or envelope protective means. See the class definition for the classification of lamps and discharge devices which are combined with a separable optical device. See the class definition for the classification of envelopes, per se, for lamps and discharge devices. SEE OR SEARCH THIS CLASS, SUBCLASS: 359.1, for discharge devices of the positive ion accelerator type which are provided with windows through which the positive lens may pass. 420, for cathode ray devices provided with electron permeable windows. 461+, for cathode‐ray tubes provided with fluorescent or phosphorescent screens or targets. 465, for cathode ray devices provided with light valves. 483+, for devices having a fluorescent material as a part thereof. 539, for photosensitive devices provided with means for transmitting particular portions of the light spectrum to the photosensitive element of the device. SEE OR SEARCH CLASS: 359,  Optical Systems and Elements,   subclasses 642+ for lenses. 362,  Illumination,   subclasses 351+ for antiglare lens and subclasses 326+ for light refractors (e.g., lenses) for use with illuminating devices where the refractor is separable from the source of light. 378,  X‐Ray or Gamma Ray Systems or Devices,   subclasses 121+ for X‐ray tubes which are provided with screening means to eliminate unwanted secondary X‐rays.

111	Plural diverse optical devices:
	This subclass is indented under subclass 110.  Devices which have structurally combined therewith a plurality of optical devices of diverse types (e.g., a reflector and a lens or a filter and a polarizer).

112	Polarizer or special ray transmission (e.g., filter):
	This subclass is indented under subclass 110.  Devices in which the optical device is a polarizer, a light filter, or which are provided with an envelope which is designed to be especially transparent to particular wave lengths of radiant energy. (1) Note. See the class definition for the classification of envelopes including those made of special compositions for electric lamps and discharge devices. SEE OR SEARCH CLASS: 252,  Compositions,   subclasses 299.01+ for liquid crystal containing compositions useful in making optical filters and subclasses 582+ for other compositions useful in making optical filters. 359,  Optical Systems and Elements,   subclasses 483+ for light polarizers and subclasses 350+ and 885+ for optical filters. 427,  Coating Processes,   for processes of coating, per se, wherein the product is an optical element. 428,  Stock Material or Miscellaneous Articles,   subclasses 415 , 417 and 426+ for a nonstructural composite web or sheet embodying a layer of glass. 501,  Compositions: Ceramic,   subclasses 11+ for glass compositions capable of filtering light.

113	Reflector:
	This subclass is indented under subclass 110.  Devices in which the optical device is a light reflector. SEE OR SEARCH CLASS: 359,  Optical Systems and Elements,   subclasses 838+ for reflectors, per se. 362,  Illumination,   subclasses 341+ , and the subclasses specified in the notes thereto for reflectors for use with light projectors where the reflector is separable from the source of light. 427,  Coating Processes,   for processes of coating, per se, wherein the product is an optical element.

114	Plural reflectors:
	This subclass is indented under subclass 113.  Devices having a plurality of reflectors.

115	Multiple filament lamps:
	This subclass is indented under subclass 113.  Devices in which the lamp is an incandescent lamp having a plurality of filaments or glowers. SEE OR SEARCH THIS CLASS, SUBCLASS: 316, and the subclasses specified in the notes thereto for other lamps which are provided with a plurality of filaments or glowers.

116	Light diffusing:
	This subclass is indented under subclass 110.  Devices in which the optical device is a light diffusing means. (1) Note. Incandescent lamps with frosted globes are included in this subclass. SEE OR SEARCH CLASS: 156,  Adhesive Bonding and Miscellaneous Chemical Manufacture,   subclasses 663+ for methods of etching glass to produce a light diffusing surface thereon. 427,  Coating Processes,   for processes of coating, per se, wherein the product is an optical element.

117	Light valve or obscuring means:
	This subclass is indented under subclass 110.  Devices in which the optical device is a light valve, or a light shield or other light obscuring means for preventing transmission of light. SEE OR SEARCH THIS CLASS, SUBCLASS: 364+, for cathode ray devices provided with light valves. SEE OR SEARCH CLASS: 359,  Optical Systems and Elements,   subclasses 227+ and 238+ for light valves, per se.

118	SPARK PLUGS:
	This subclass is indented under the class definition.  Unitary devices known as spark plugs. (1) Note. See the glossary for the class definition of spark plugs. In general, the spark plugs classified herein are the jump spark type found in the gasoline engine of an automobile. (2) Note. The shell is the part having means usually threaded for attachment to the cylinder. The shell may be made of more than one piece. Some plugs do not have a shell, the insulating core being attached directly to the cylinder, as by having screw threads thereon. The core is the insulating means fastened to the shell and holding the center electrode with respect to the shell. It may consist of several parts which may or may not be cemented to each other. The center electrode is the electrode or wire extending from the exterior to the interior of the spark plug and which is insulated from the shell by the core. There may be several center electrodes insulated from each other. The spark electrodes are the electrodes between which the jump spark is formed. The ignition spark gap is the gap on the interior of the spark plug designed to ignite the combustible fuel. A spark gap is constituted by two or more spark electrodes. The interior of the spark plug is the portion which will be exposed to the combustible gas. The exterior is the part usually exposed to atmosphere and which has the connector for the ignition wire mounted thereon. Electrode chamber is the space defined by the interior part of the core and the shell and exposed to the combustible gas in the engine. It may be substantially flat in some cases. (3) Note. Spark plugs are collected here on the basis of use, art and structure. Spark plugs having the usual structure of a shell, an insulating core with one or more electrodes therein are found here. Due to the rules of classification, certain types of spark plugs and combinations of spark plugs with accessories are classified in the lower numbered subclasses of this class. Also, since the presence or absence of claimed sparking electrodes determines the classification in this class, a number of other classes provide for bushings, connectors, shields, joints and other subcombination features. Such other subclasses and classes are referred to in the notes below, and in cases where only a few patents are classified in other subclasses or classes and which are not noted in the notes, cross‐reference patents have been placed in this and the indented subclasses. (4) Note. Spark Intensifiers for Spark Plugs: Intensifier spark gaps designed for use with spark plugs are not classified in this or the indented subclasses unless the intensifier gap is a unitary part of the complete spark plug when see subclasses 123+. Where only the spark plug bushing (i.e., shell, core, center wire) is claimed, no ignition spark electrodes being claimed, the intensifier gap being located in or on the bushing, the patent is likewise excluded and classified as an intensifier gap. Some of the subclasses to be searched for these intensifier gaps are: 1+, where there are a plurality of intensifier gaps in a unitary device; 51, where the intensifier is claimed in combination with a detachable electric connector; 110+, where the intensifier includes an optical element as a lens, mirror, etc.; 146+, where the intensifier is provided with a movable or adjustable electrode or shield (e.g., a screw threaded electrode so that the size of the gap may be adjusted); 238+, especially 243, 267, 268 where the supporting or spacing structure for mounting the intensifier electrodes are claimed; see subclass 267 where the electrodes are rods or rod‐like members, subclass 268 where the electrodes are held apart by an insulating member between the electrodes, and subclass 243 for the other type; 324, for the intensifiers with a casing including those having a transparent window; and 567, especially 620+, 622, 634+ where the intensifier is mounted in a sealed envelope containing gas or vapor. SEE OR SEARCH THIS CLASS, SUBCLASS: 1+, for unitary devices providing two or more separate spark plug gaps or providing a spark plug gap and another discharge device, but excluding spark plugs with intensifier gaps for which see subclasses 123+ and spark plugs with a plurality of series spark gaps for which see subclass 123. 10, for spark plugs combined with a temperature indicator. 11.5, for spark plugs with temperature modifying means. 51, for spark plugs claimed in combination with a detachable electric connector (e.g., the connector on the lead‐in wire). 54, for spark plugs which include a radioactive material. 110+, for spark plug devices which include means, see subclass 110 where the plug includes a lens, subclass 113 where the plug is combined with a mirror, subclass 116 where the plug includes a prism or light diffusing means. 513+, where the plug includes indicia or a scale (e.g., to show width between the ignition electrodes). SEE OR SEARCH CLASS: 15,  Brushing, Scrubbing, and General Cleaning,   subclass 104.011 for spark plug cleaners. 73,  Measuring and Testing,   subclasses 114.62 through 114.67for measuring or testing the ignition system of an internal combustion engine and subclass 114.08 for using an ignition measurement for determining irregular combustion (e.g., misfire) using an ignition measurement. 123,  Internal‐Combustion Engines,   subclasses 143+ , especially subclasses 169 and 594+ for this subject matter in combination with an internal combustion engine or engine accessory. Subclass 169 relates, for example, to the combination of a spark plug and a cylinder head; the combination of a plug and cylinder space in which the interior of the skirt has a special claimed relationship to the cylinder volume the combination of a spark plug with an adaptor of the screw coupling type (which, for example, permits a small plug to be inserted in a large hole or which acts to extend the shell skirt to provide a chamber for the spark), etc. Also search Class 123 for plural separate spark plugs such as, for example, a plurality of adjustable spark plugs having means to adjust them. 138,  Pipes and Tubular Conduits,   subclasses 37+ for fittings or adapters to be interposed between the spark plug and the cylinder which include a flow regulator or baffle. 174,  Electricity: Conductors and Insulators,   appropriate subclasses for spark plug‐type electrical bushings (i.e., a spark plug with no sparking electrodes claimed), and electrical shields for spark plugs; subclasses 15.1 through 16.3for such bushings combined with means for feeding, circulating, or distributing a fluid, such as a cooling liquid or air; subclass 31 for such bushings with a fluid (air) vent, valve, or other fluid feeding means combined therewith (e.g., a priming means); subclasses 152+ for such bushings, per se, including such bushings as are provided with thermal modifying means (e.g., heat radiating fins or heat conductive members) and electrical connectors; and subclass 350 for such bushings with an electrical shield about it and for the spark plug shields, per se. Note that Class 174 provides for subcombinations of spark plug type bushings which are less than a complete bushing and more than is provided for in other subcombination classes (e.g., the combination of the insulator and center electrode which involves more structure than a mere joint would be in Class 174 rather than one of the classes providing for joints. 285,  Pipe Joints or Couplings,   appropriate subclasses for fittings or adapters having joint means to attach one end of the fitting to the engine and joint means at the other end to receive a spark plug. 315,  Electric Lamp and Discharge Devices: Systems,   subclasses 32+ for space discharge devices, such as spark plugs, having integral therewith a circuit element such as a resistor, condenser or switch. Note particularly indented subclass 46 for spark plugs having a resistor in shunt to the sparking electrodes which is adapted to flash‐over when traversed by a high current impulse, said flash‐over serving to ignite the combustion charge; indented subclasses 51+ for spark plugs having a plurality of circuit elements, such as a resistor and a condenser; subclass 56 for spark plugs having an integral switch; subclass 57 for spark plugs having an integral transformer, and subclass 58 for spark plugs having a suppressor resistor. Note that spark plugs having only an integral intensifier (i.e., series connected gap) are classified in subclasses 123+ of Class 313. The presence of a separable connector or merely conductive lead (e.g., ignition cable) will not prevent classification in Class 315, subclasses 32+ if the device is otherwise classifiable there. Class 315 also provides for systems for supplying electrical energy to spark gaps. Note especially subclasses 209+ for such systems having a periodic switch (e.g., a timer switch) in the circuit and subclasses 211+ where there are a plurality of spark plugs and the system includes a distributor type switch. 324,  Electricity: Measuring and Testing,   subclasses 378 through 402for spark plug testers. 361,  Electricity: Electrical Systems and Devices,   subclasses 247+ for miscellaneous ignitors and ignitor systems. 403,  Joints and Connections,   appropriate subclasses for a joint between metal and glass or ceramic members. 439,  Electrical Connectors,   appropriate subclasses for an electrical connector or certain connector related accessories. Note that this class includes the combination of an electrical connector with a named spark plug. Search especially subclasses 125+ for an electrical connector having a spark or glow plug cover. Also, search subclasses 191+ for the combination of an electrical connector with a fluent material transmission line. Search subclasses 271+ for an electrical connector with a packing or gasket to seal the joint with a mating connector; subclasses 312+ for a coupling part with coupling part movement‐ actuating means or retaining means in addition to a contact thereof with relatively pivotable concentric movement‐actuating or retaining ring. Search this class, subclasses 607.01‐607.05 for a connector with a radiation shielding means; and subclasses 625+ for a connector with insulation other than a conductor sheath. 445,  Electric Lamp or Space Discharge Component or Device Manufacturing,   subclass 7 for methods of manufacturing spark plugs. 501,  Compositions: Ceramic,   appropriate subclasses for ceramic compositions used for spark plug insulators. Note especially subclasses 127+ and 134+ for clay containing compositions; and subclasses 141+ for titanate and similar material containing compositions.

119	Sealing‐off valve for electrode chamber:
	This subclass is indented under subclass 118.  Subject matter having means, integral with the spark plug, permitting the removal of a part of the spark plug from normal operating position with respect to the portion of the shell which is attachable to the cylinder, without forming an open passageway from the cylinder to the atmosphere. (1) Note. Included in this subclass are only unitary spark plugs. See Class 123, Internal‐Combustion Engines, subclasses 143+, especially 169 for similar subject matter where the plug is combined with another separable device (as a fitting with a valve) which permits removing of the plug without stopping the engine. (2) Note. These spark plugs are designed usually to permit inspection or repair of the ignition spark gap electrodes or of the interior end of the insulator without stopping the operation of the engine. SEE OR SEARCH THIS CLASS, SUBCLASS: 236, for other discharge devices which have a stand‐by or spare electrode. 237, for other discharge devices which have electrode replacement means or are demountable. SEE OR SEARCH CLASS: 137,  Fluid Handling,   appropriate subclasses for automatically operated valves. 251,  Valves and Valve Actuation,   appropriate subclasses for manually operated valves.

120	With fluid feed or air vent:
	This subclass is indented under subclass 118.  Subject matter provided with a passageway for a fluid extending through the spark plug structure from the interior of the spark plug to the exterior or to a fluid feed line so that a liquid or gas may flow between the electrode chamber and the exterior of the spark plug or the fluid feed line. (1) Note. The passageway may be provided with a valve so that the fluid may pass in one direction only or have a valve so that the fluid feed line may be closed or opened as desired. (2) Note. The fluid feed or air vent, for example, may supply priming fluid to the ignition spark gap space, or may blow oil off the electrodes or allow some of the burned gas to escape. Included in this subclass are spark plugs in combination with integral fuel injection nozzles. (3) Note. The fluid feed or air vent may, for example, act as an observation port for visual inspection of the ignition spark gap or as a port for the insertion of a cleaner. SEE OR SEARCH THIS CLASS, SUBCLASS: 11.5, for this subject matter when the fluid passageway is for the purpose of supplying a cooling fluid (e.g., air) to the spark plug. 119, for spark plugs having valve means arranged so that the interior of the plug or part of the shell may be sealed off to permit removal or inspection of at least part of the plug without stopping the engine. 143, for spark plugs having gas directing means, such as baffles or valves in the electrode chamber where there is no fluent passageway between the interior and the exterior of the plug. 231.01+, for other discharge devices which have a fluent material supply means or flow directing means. SEE OR SEARCH CLASS: 123,  Internal‐Combustion Engines,   subclasses 179.9+ for priming devices for internal combustion engines. 137,  Fluid Handling,   subclasses 455+ for automatically operated valves responsive to the fluid passing through the valve, see especially subclasses 511+ for automatically operated check valves. 239,  Fluid Sprinkling, Spraying, and Diffusing,   appropriate subclasses, for fuel injection nozzles for internal combustion engines, especially subclasses 86 through 96, and 584+. See also (2) Note, above. 251,  Valves and Valve Actuation,   appropriate subclasses for manually operated valves.

121	Reversible (e.g., part):
	This subclass is indented under subclass 118.  Subject matter in which the whole or a portion thereof is reversible. (1) Note. This subclass relates, for example, to spark plugs in which the core can be reversed, so that the center electrode tip becomes the binding post and vice versa. SEE OR SEARCH THIS CLASS, SUBCLASS: 144+, for spark plugs having specific joint structure such as between the insulator and the shell. 236, for other discharge devices which are provided with a stand‐by or spare electrode.

122	Removable electrode on shell:
	This subclass is indented under subclass 118.  Subject matter in which one of the ignition spark electrodes is supported by the shell, and is mounted so as to be removable therefrom. (1) Note. The removable electrode supported by the shell may be attached to a sleeve or other supporting means fastened between the shell and core so that the core must be removed to remove the electrode. SEE OR SEARCH THIS CLASS, SUBCLASS: 128, for spark plugs wherein the core supports a plurality of separate ignition electrodes with individual lead‐in wires which are insulated from each other.

123	Plural series gaps:
	This subclass is indented under subclass 118.  Subject matter having a plurality of spark gaps connected in series. (1) Note. The plural gaps may be located on the interior portion of the plug (e.g., used to ignite the combustible gas) or one or more of the gaps may be located in or on some other portion of the spark plug. (2) Note. Spark gaps in series with the igniter spark gap, when not exposed to the cylinder charge, are often referred to as intensifier gaps, since they prevent voltage break‐down until a voltage level, higher than would otherwise be required, is reached. SEE OR SEARCH THIS CLASS, SUBCLASS: 306+, and the subclasses specified in the notes thereto for miscellaneous discharge devices having a plurality of gaps in series. SEE OR SEARCH CLASS: 315,  Electric Lamp and Discharge Devices: Systems,   subclasses 180+ for systems for supplying electrical energy to a plurality of different type spark gaps, subclasses 185+ for systems for supplying electrical energy to a plurality of series connected spark gaps, subclass 334 and the subclasses specified in the notes thereto, for supplying electrical energy to a discharge device having three or more series arranged electrodes.

124	Intensifier in center electrode lead‐in:
	This subclass is indented under subclass 123.  Subject matter in which one of the series gaps is located in the lead‐in path which includes the center electrode connector for the ignition wire and the ignition spark electrode conductively attached to or formed by the center electrode, the gap being located outside of the interior portion of the spark plug (e.g., not in the electrode chamber). (1) Note. Where all of the series gaps are exposed to the cylinder charge so as to form ignition spark gaps, or where the intensifier is located, not in the center electrode but rather in a noncenter electrode return circuit or lead‐in, the art will be found in subclass 123 above. (2) Note. The center electrode may be formed of plural parts with the spaced electrode parts forming the intensifier gap, or the center electrode may be spaced from the connector for the ignition wire so as to form an intensifier gap with a portion of the connector structure, or it may be otherwise arranged so as to be in the center electrode lead‐in path. (3) Note. Spark Intensifiers for Spark Plugs: Intensifier spark gaps designed for use with spark plugs are not classified in this or the indented subclasses unless the intensifier gap is a unitary part of the complete spark plug, when see subclasses 123+. Where only the spark plug bushing (i.e., shell, core, center wire) is claimed, no ignition spark electrodes being claimed, the intensifier gap being located in or on the bushing, the patent is likewise excluded and classified as an intensifier gap. See Search This Class, Subclass, below, for some of the subclasses to be searched for these intensifier gaps are: SEE OR SEARCH THIS CLASS, SUBCLASS: 1+, where there are a plurality of intensifier gaps in a unitary device. 51, where the intensifier is claimed in combination with a detachable electric connector. 110+, where the intensifier includes an optical element as a lens, mirror, etc.. 146+, where the intensifier is provided with a movable or adjustable electrode or shield (e.g., a screw threaded electrode so that the size of the gap may be adjusted). 267, where the electrodes are rods or rod‐like members. 268, where the electrodes are held apart by an insulating member between the electrodes, and subclass 243 for the other type. 282+, especially 243, 267, 268 where the supporting or spacing structure for mounting the intensifier electrodes are claimed. See subclass 324, for the intensifiers with a casing including those having a transparent window. 567, especially 620+, 622, 634+ where the intensifier is mounted in a sealed envelope containing gas or vapor. SEE OR SEARCH CLASS: 315,  Electric Lamp and Discharge Devices: Systems,   subclasses 58+ for similar subject matter having a circuit impedance such as, for example, a nonlinear resistor in the center electrode lead‐in.

125	Movable electrode (e.g., for cleaning, adjustable):
	This subclass is indented under subclass 118.  Subject matter having an ignition spark electrode which is movable into two different positions. (1) Note. For the purpose of this definition, an electrode which is variably positioned by plastic distortion thereof (as, for example, when points are "set" to a desired position by bending to provide a particular gap length) is not considered to be movable. Where the distortion is an elastic deformation as, for example, due to vibration, the art is in this and the indented subclass. (2) Note. In general, this subclass includes spark plugs provided with means whereby an electrode may be moved other than by plastic distortion without disassembly of the spark plug. The electrode may be moved for cleaning or for obtaining a variable width ignition gap. SEE OR SEARCH THIS CLASS, SUBCLASS: 119, for this subject matter where the spark plug can be removed from normal operating position without stopping the engine. 120, for spark plugs having a reversible electrode which can assume one position or a reversed position. 122, for spark plugs having a removable electrode on the shell. 127, for spark plugs having stationary electrodes and a movable cleaner. 143, for spark plugs having a movable baffle or gas directing means for the electrode chamber. 146+, for other space discharge devices having a movable electrode.

126	Automatically moved (e.g., engine vibration):
	This subclass is indented under subclass 125.  Subject matter in which the electrode is automatically moved. (1) Note. The electrode may be moved, for example, by engine vibration or by a thermostat. The motion may be effected so as, for example, to adjust the spacing of the spark gap electrodes or to clean the electrodes. (2) Note. This subclass also includes spark plugs having means for automatically moving electrodes and means for disabling said first mentioned means so that the electrodes can optionally be held immovable. (3) Note. This subclass includes spark plugs having both manual and automatic means to move an electrode. SEE OR SEARCH THIS CLASS, SUBCLASS: 127, for spark plugs having automatically moved cleaners. 143, for spark plugs having automatically moved baffles or gas directing means for the electrode chamber.

127	Cleaner (e.g., movable scraper):
	This subclass is indented under subclass 118.  Subject matter having a cleaner. (1) Note. The cleaner may, for example, be a movable scraper which scrapes the electrode tips or movable balls which knock carbon off the insulator. (2) Note. Many spark plugs are "self cleaning" by virtue of their operating at a sufficiently high temperature to burn off carbon deposits. Such spark plugs are not classified in this subclass unless they have means for cleaning in addition to the means which produce the high temperature operation. SEE OR SEARCH THIS CLASS, SUBCLASS: 120, for spark plugs having fluid feed or vent means, through which means a cleaner may be inserted to clean the electrodes or other parts. 125+, for this subject matter in which an electrode is movable as, for example, where an electrode can be rubbed against another electrode or where an electrode vibrates during use to shake off deposits or where a movable scraper is an electrode tip. SEE OR SEARCH CLASS: 15,  Brushing, Scrubbing, and General Cleaning,   subclass 104.011 for spark plug cleaners, per se.

128	Plural insulated electrodes with individual lead‐in:
	This subclass is indented under subclass 118.  Subject matter having plural ignition spark electrodes which are insulated from the shell, and from each other, each of the so insulated electrodes having its own lead‐in structure. (1) Note. The spark plug may have three or more ignition spark electrodes, one of which is mounted on the shell, at least two of the others being insulated from the shell and having individual lead‐in conductors. SEE OR SEARCH THIS CLASS, SUBCLASS: 123+, for spark plugs having plural series connected ignition gaps. 140, for spark plugs having a plurality of parallel connected gaps, e.g., having a plurality of ignition spark electrodes connected together which cooperate with the electrode mounted on the shell to form a plurality of parallel connected ignition gaps. 306+, and the subclasses specified in the notes thereto for other discharge devices having three or more electrodes. SEE OR SEARCH CLASS: 439,  Electrical Connectors,   subclasses 626+ and 709+ for electrical connector structure having a plurality of terminals which are insulated from each other mounted upon an insulating member.

129	With transparent part:
	This subclass is indented under subclass 118.  Subject matter having a transparent part. (1) Note. The transparent part may, for example, make the spark or explosion inside the engine cylinder visible to an observer. SEE OR SEARCH THIS CLASS, SUBCLASS: 110+, for spark plugs where the transparent part is an optical device such as, for example, a lens. See subclass 116 where the transparent part has light diffusing properties. 120, for spark plugs having fluid feed or air vent means, through which the spark gap may be observed. 124, for spark plugs having an intensifier gap and the portion of the plug having the intensifier gap is provided with an observation window or is made transparent. 324, for miscellaneous spark gaps which are provided with a casing having a transparent part.

130	Non‐conducting material in or adjacent gap (e.g., restricts spark):
	This subclass is indented under subclass 118.  Subject matter having nonconducting material interposed between or closely adjacent the ignition spark gap. (1) Note. The nonconducting material, for example, may be provided with a minute aperture through which the spark must pass, or it may be an impervious barrier between the electrodes. (2) Note. For the purpose of this definition, the material is closely adjacent the spark gap if it is so close that it affects the sparking. SEE OR SEARCH THIS CLASS, SUBCLASS: 143, for spark plugs having an insulator end at the ignition spark gap end of the plug of particular shape. 325, for miscellaneous spark gaps having an insulator material within or closely adjacent to the spark electrodes. SEE OR SEARCH CLASS: 315,  Electric Lamp and Discharge Devices: Systems,   subclass 46 for similar subject matter where the material with or closely adjacent the gap is a resistance material.

131	Non‐shortest line spark and surface spark type:
	This subclass is indented under subclass 130.  Subject matter in which the material is so situated that the spark is caused to follow the surface of the insulator or to follow a path which is not the shortest path between electrodes. (1) Note. For example, the insulating material may form a barrier between the sparking electrodes so that the spark must jump the barrier.

132	Capillary groove or space:
	This subclass is indented under subclass 118.  Subject matter having a groove or analogous surface structure or having a narrow space which is disclosed as drawing or holding fluid by capillary action. (1) Note. The fluid, for example, may be condensed oil mist which is drawn away from the electrode points by capillary action. (2) Note. The narrow space may be formed, for example, between two facing flat electrodes of extended area positioned closely together. SEE OR SEARCH THIS CLASS, SUBCLASS: 141+, and the subclasses specified in the notes thereto, for spark plug ignition electrode structure, not having capillary grooves, in which condensed fluid is drawn away from electrode points by gravity action due to the inclination of a surface of the electrode.

133	Ball electrode:
	This subclass is indented under subclass 118.  Subject matter having an ignition electrode whose shape is that of a ball or a substantial portion of a ball. (1) Note. This subclass relates, for example, to spark plugs in which one electrode is a substantially hemispherical or hemispheroidal surface formed of a thin sheet material. SEE OR SEARCH THIS CLASS, SUBCLASS: 325, and the subclasses specified in the notes thereto for other discharge devices having ball electrodes, and subclass 326 for the electrodes, per se.

134

With radio shielding:

This subclass is indented under subclass 118.  Subject matter having electrical shielding means to shield the spark plug. (1) Note. The shielding means ordinarily are used to prevent the ignition current used with the spark plug from radiating or otherwise establishing unwanted electrical effects. SEE OR SEARCH THIS CLASS, SUBCLASS: 313, for other space discharge devices having electric shielding means. SEE OR SEARCH CLASS: 123,  Internal‐Combustion Engines,   subclasses 146.5+ for shielded ignition systems for internal combustion engines. 174,  Electricity: Conductors and Insulators,   subclasses 32 through 397for electrical conductors having shielding means and subclass 350 for miscellaneous electrical shielding structure including that designed for use with spark plugs or spark plug‐type bushings.