This class includes all those devices commonly known as electric heaters, electric-heating metal working apparatus, electrically-heated tools and instruments. Processes are classified with the apparatus unless otherwise indicated by the subclass title.
This is the generic class for electric heating devices, per se. Devices and systems equipped with electric heating means in which the electric heating means is combined with or includes specific other art structure whereby the heated material is withdrawn, stored or otherwise utilized will be classified in the appropriate other art class to which it pertains and cross referenced back to Class 219.

LINES WITH OTHER CLASSES AND WITHIN THIS CLASS
An example of other classes as mentioned above in the Class Definition is Class 122, Liquid Heaters and Vaporizers in which such terms as steam dome, super heaters, steam separators, condensers, traps, etc., are considered to be art structure over and beyond the mere heating of a liquid and comprising specific means for further storing or utilizing the liquid or vapor resulting from a heating step and sufficient to exclude the claimed subject matter from this class.
The liquid heaters to be found in this class, subclasses 281+ are very similar to those classified in Class 122 and in Class 126, subclasses 344+. The general line to be followed in distinguishing between this and those classes is as follows: Where the claims recite specific electrical means
for heating a liquid only and the end result recited is a heated liquid only and no further means is claimed for withdrawing the liquid for further use the device will be considered a liquid heater for this class. For an understanding of the lines between Classes 122 and 126 consult the class definitions and the notes thereunder.

REFERENCES TO OTHER CLASSES

SEE OR SEARCH CLASS:
5, Beds, subclass 284 for bed structures with devices for heating or cooling of, and subclass 421 for devices for supporting bed clothing with heating means.
12, Boot and Shoe Making, subclass 1 for miscellaneous shoe machinery with heaters, subclasses 32.1, 33.2 and 41.5 for sole machines with electric heaters, subclasses 53.1, 53.3 and 69.7 for heel machines with electric heaters, subclass 78.5 for sole and/or heel burnishing machines with heating means, and subclasses 114.2, 114.6, 116.2, 117.4, and 129.4 for tools or forms used in shoe manufacturing with heating means.
15, Brushing, Scrubbing, and General Cleaning, subclass 1.5 for electrostatic cleaning, subclasses 300.1+ for cleaning by air blast or suction wherein the fluid may be heated and subclasses 104.001+ for implements which may be heated.
19, Textiles: Fiber Preparation, subclass .27 for drying apparatus.
26, Textiles: Cloth Finishing, 3 for singeing devices which may utilize electric heating means.
30, Cutlery, subclass 32 for wire razor devices, subclasses 34.05+ for razors combined with heated blade, and subclass 42 for the combination where the blade is movable.
34, Drying and Gas or Vapor Contact With Solids, 519 for processes which may utilize electric heaters particularly subclass 283 for drying the hair on the head and the subclasses under the title "Apparatus" for particular drying apparatus which may utilize electric heating means.
36, Boots, Shoes, and Leggings, subclass 2.6 for boots and shoes with heating means.
38, Textiles: Ironing, or Smoothing, 74 for flat irons which may include electrical heating devices by name only.
44, Fuel and Related Compositions.
48, Gas: Heating and Illuminating, subclass 65 for cupola gas generators wherein electric current is used for heating purposes, and subclass 103 for retorts in which is located an electric heater for gasifying the oil.
60, Power Plants, subclass 523 for a motor operated by the expansion and contraction of a unit mass where the expansion is caused by an electrical heating means.
62, Refrigeration, particularly subclass 148, 159+, 167, 238, 275+, 324+, and 351 for heating means associated with refrigeration apparatus.
65, Glass Manufacturing, appropriate subclasses for glass working apparatus utilizing electrical heating means particularly subclass 40 for means employing dielectric or joule effects and subclasses 152+ for fusion bonding devices.
70, Locks, appropriate subclasses for heater lock combinations according to the particular lock structure.
72, Metal Deforming, appropriate subclasses for heating metal by a means other than electricity and deforming it.
73, Measuring and Testing, appropriate subclasses for measuring or testing devices with electrical heating means for testing purposes or for maintaining constant temperature.
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, for patents claiming a metal composition, e.g., an alloy or a composition having a continuous phase of free metal made by consolidating metal particles.
81, Tools, appropriate subclasses for particular tool structure which may be combined with heating means.
83, Cutting, 170 for cutting apparatus combined with means to modify or control the temperature of the apparatus or work.
96, Gas Separation: Apparatus, appropriate subclasses, for gas separation apparatus having heating or cooling means.
99, Foods and Beverages: Apparatus takes food support means, peculiar to a food, shape, or condition, (e.g., can, jar, bottle, or slice holders, spits, griddles, waffle irons, sandwich grills, article confining or conforming supports), including a mechanism for manipulating food during cooking, other than mere agitation or stirring (e.g., conveying or bodily moving), or including a mechanism for treating food (e.g., basting, compressing, molding, drip, or gravy segregating), and, in any case, irrespective of whether or not a heat, steam, or vapor generator or enclosure is claimed; 324 for cooking apparatus.
100, Presses, 92 for a press having an additional heating, cooling, or drying means to treat material or subclass 102
for a press that may be combined with an electrical heating means.
101, Printing, see 3.1, especially subclasses 8, 9+, 21, 25, 27, and 31 for embossing or penetrating devices utilizing heated dies.
104, Railways, subclass 15 for electric welders for track joints and subclass 279 for track clearing devices comprising rail heaters.
105, Railway Rolling Stock, especially subclass 451 for heating devices which may be electrical.
110, Furnaces, subclass 194 for cremation apparatus that may utilize electric heating means; and subclass 250 for a refuse incinerator provided with an electric heater.
118, Coating Apparatus, appropriate subclasses, especially subclass 47 for coating burning apparatus, and subclasses 50.1, 58+, 620+, 663+, and 723+ for coating devices with means for applying electrical or radiant energy to work and or coating material, particularly subclasses 641+ for radiant heating devices.
119, Animal Husbandry, 308 for a brooder warmed by an electrical component, or subclasses 318+ for an incubator warmed by an electrical component.
122, Liquid Heaters and Vaporizers, appropriate subclasses for steam generating devices which may utilize electric heating means.
123, Internal-Combustion Engines, particularly 543 for means for heating the carburetor, subclass 142.5 for the combination of an internal combustion engine combined with external heating means for heating the engine or some adjunct thereof and subclass 145 for incandescent igniters.
126, Stoves and Furnaces, appropriate subclasses for structural features peculiar to stoves and furnaces, see particularly subclass 273.5 for domestic ovens with heat accumulators and subclass 400 for heat accumulators, per se.
128, Surgery, appropriate subclasses for various instruments combined with heating means or designed for the utilization of heat energy for therapeutic treatment of the human body.
131, Tobacco, subclass 185 for tobacco users' appliances with igniter means.
132, Toilets, subclass 7 for methods of hair treating comprising permanent waving with heat and subclass 118 for hair combs with heaters and subclass 148 for combs combined with other features; see also subclasses 31+ for hair crimpers or curlers which may include heaters.
134, Cleaning and Liquid Contact With Solids, 105 for apparatus with heating, cooling or heat exchange means.
136, Batteries: Thermoelectric and Photoelectric for batteries in that class having heating means.
137, Fluid Handling, subclass 341 for electric heating means for the system.
138, Pipes and Tubular Conduits, subclass 33 for electric thawing or freeze protection means therefor.
140, Wireworking, subclass 112 for processes for joining of wires by electric welding.
141, Fluent Material Handling, With Receiver or Receiver Coacting Means, subclass 82 for the treatment of material by heating or cooling.
148, Metal Treatment, particularly subclass 520, 525, and 565 for processes of significant heat treatment of metal to modify or maintain the internal physical structure (i.e., microstructure) or chemical property of metal wherein electrical heating is utilized. See Lines With Other Classes, "Metal Casing, Metal Fusion Bonding, Machining, or Working Classes" to determine what constitutes significant heat treatment.
164, Metal Founding, appropriate subclasses for metal casting apparatus which may employ an electric heater.
165, Heat Exchange, appropriate subclasses for systems comprising both heating and cooling means or heat transfer, particularly 200 for automatic control; subclass 42 for vehicle heating and cooling and subclasses 47+ for structural installations such as radiant building panels.
166, Wells, subclass 60 for well structure with an electric heater in the well.
174, Electricity: Conductors and Insulators, appropriate subclasses for insulator devices and structural details of electrical conductors, per se.
175, Boring or Penetrating the Earth, subclass 16 for an electrical heating process or device for forming a hole in the earth by directly applying heat to fluidize or comminute the material forming the earth. (See Lines With Other Classes and Within This Class, in the class definition of Class 175 for the line between Class 175 and Class 219).
178, Telegraphy, subclass 94 for pyros:graphic code recorders.
184, Lubrication, subclass 104 for heating and cooling devices for lubricators.
191, Electricity: Transmission to Vehicles, subclass 62 for trolley heads with heated ice clearers or preventers.
196, Mineral Oils: Apparatus, subclass 121 for vaporizing devices with electric heating means.
200, Electricity: Circuit Makers and Breakers, for generic circuit maker and breaker structure, or 308 for an electrical switch having indicator means.
201, Distillation: Processes, Thermolytic, subclass 19 for a thermolytic distillation in which electrical energy is applied.
204, Chemistry: Electrical and Wave Energy, particularly subclass 210, 236, 239, 241, 262, and 274 for electrolytic apparatus utilizing heating or cooling means.
210, Liquid Purification or Separation, 175 for devices with heating or heat exchange means.
216, Etching a Substrate: Processes, with the use of a plasma, note 67. The use of a cold plasma, which is a chemical reaction involving reactive ions and an article or substrate is not proper for Class 219, Electric Heating. However, cold plasma is proper for Class 216, Etching a Substrate: Processes. The use of a high temperature thermal plasma which removes or alters material by thermal means is proper for Class 219, Electric Heating.
221, Article Dispensing, subclass 143 for dispensing devices with electrical ignition means and subclass 150 for such devices with article treatment involving heating or cooling.
222, Dispensing, subclass 146 for dispensers with heating or cooling.
223, Apparel Apparatus, subclass 26 for heated hat forms, subclasses 51, 70, 73, and 76 for apparatus including heating and steaming means and subclass 79 for heated glove forms.
236, Automatic Temperature and Humidity Regulation, appropriate subclass for heating systems beyond the scope of Class 219 and involving automatic temperature control devices.
237, Heating Systems, appropriate subclasses for complete heating systems in which the heat source may be electrical.
239, Fluid Sprinkling, Spraying, and Diffusing, 128 for heating or cooling means for the fluid or system.
244, Aeronautics, subclass 134 for ice prevention devices utilizing electric heating means.
250, Radiant Energy, 316 for infrared or thermal pattern recorders or document copiers, subclass 337 for a radiant
energy electric signalling device responsive to luminous energy emitted from a heated luminophor irradiated by invisible radiation subclass 352 but conduction to or from some part of an infrared responsive electric signalling means, subclass 429 for temperature control of contained supported transferred fluent material, subclass 443.1 for a support for an object to be irradiated with charged particles with heat transfer to or from the object, and subclass 495.1 for plural invisible radiation sources including an infrared source, subclass 504 for an infraradiation source with a radiation modifying member and subclass 238 for photocells with temperature control.
261, Gas and Liquid Contact Apparatus, subclass 139 and 142 for such apparatus with an electrical external heat supply.
266, Metallurgical Apparatus, appropriate subclasses for such apparatus with electrical heating devices.
285, Pipe Joints or Couplings, subclass 41 for such devices with heating or cooling means.
290, Prime-Mover Dynamo Plants for prime mover dynamo plants for producing heat.
307, Electrical Transmission or Interconnection Systems, 112 for a residual switching system.
310, Electrical Generator or Motor Structure, 341 for piezoelectric crystals with temperature control means in which electrical circuit connections and the crystal are claimed.
312, Supports: Cabinet Structure, subclass 236 for such structures with heating, cooling or heat exchange means.
313, Electric Lamp and Discharge Devices, appropriate subclasses for electric lamp, filament or cathode heaters, particularly 11 including indented subclass 14 for pyroelectric devices and subclasses 15+ for such devices with electric heater temperature modifier means.
314, Electric Lamp and Discharge Devices: Consumable Electrodes, particularly 26 for such devices with temperature modifying means.
315, Electric Lamp and Discharge Devices: Systems, particularly 46 49, 50, 94+, and 112+ for systems with heated filaments, cathodes or device temperature modifiers.
323, Electricity: Power Supply or Regulation Systems, for a generic class of electrical systems wherein a single electrical source is coupled to a single electrical load circuit and means are provided which control the magnitude or level of the current or voltage of either or both of said circuits, especially subclass 236 for other than an electrical zero switching output level condition responsive
(e.g., heat, etc.) circuit.
331, Oscillators, subclass 70 for oscillator with temperature modifier.
336, Inductor Devices, 55 for inductors with temperature modifiers.
337, Electricity: Electrothermally or Thermally Actuated Switches, appropriate subclasses for specific switch structure with thermal actuating means.
338, Electrical Resistors, appropriate subclasses for electrical resistors, per se. The mere claiming of a resistor having a heat insulating or heat conducting casing or housing does not exclude Class 338. However, as between Classes 219 and 338 the combination of a resistor used for heating purposes surrounded or incased by the structure to be heated or a resistor with structure or configuration for distributing, directing or concentrating the heat produced by the resistance is classified in this class (219), especially 200. See also Lines With Other Classes and Within This Class, "Electrical Resistance Heaters," in the class definition of Class 338 for a more detailed treatment of the line between the two classes.
340, Communications: Electrical, subclass 309.15 for a timer controlled system, subclasses 384.1+ for an audible signaling device, especially subclass 387.1 for weatherproofing (e.g., means to melt sleet off of a signal device, etc.), subclasses 577+ for a flame condition responsive system, subclasses 584+ for a thermal condition responsive system, subclass 600 for radiant energy condition responsive system, subclasses 635+ for electrical apparatus condition responsive system, especially subclass 640 for a heater element condition responsive system, subclass 655 for a condition responsive system indicating heating circuit energization, subclasses 815.4+ for visual indication systems or subclasses 825+ for miscellaneous remote control systems.
343, Communications: Radio Wave Antennas, subclass 704 for antennas with ice clearer or preventers which may utilize electric heaters.
346, Recorders, subclass 76.1 for thermal recording of phenomenon.
347, Incremental Printing of Symbolic Information, 171.1 for thermal marking processes or apparatus.
355, Photocopying, 3 for electrophotography devices utilizing heating means.
361, Electricity: Electrical Systems and Devices, 1 for safety and protection of systems and devices; indented subclasses 24, 25+, 32, 34, 37, and 103+ provide thermal sensing devices in various circuits or systems; subclasses 99
and 211 for combinations including thermal relays and control circuits for thermal relays; subclass 158 for thermal indicating instrument; subclasses 161+ for control circuits including a thermal device and subclasses 247+ for igniting systems.
362, Illumination, 92 for the combination of illuminating means and a heating device.
373, Industrial Electric Heating Furnaces, for furnaces which are especially adapted to metallurgical and related work. Such furnaces are generally characterized by electrical heating means within the chamber containing the material to be heated, the heating means being either an arc, a resistance, the material itself or a combination of such means and are further characterized by adaptation for operation on a granular material, such as crushed ore or for handling molten material fusing at a very high temperature, the material in both cases being received immediately within the body of the furnace.
374, Thermal Measuring and Testing, including electric heating arrangements to perfect a measurement or test or to maintain a constant temperature.
401, Coating Implements With Material Supply, 1 for a hand-manipulated coating implement with means to heat the material supply contained therein.
405, Hydraulic and Earth Engineering, subclass 56 and 131 for devices for heating the earth which may use electrical heating means; and subclass 234 for a heating means employed in the installation of piling.
422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing, subclass 21 and 22+ for processes of sterilizing with electric energy subclasses 186.19 and 186.2 for radiant energy chemical reactors with heating or cooling means; and subclasses 242 and 295+ for autoclaves.
425, Plastic Article or Earthenware Shaping or Treating: Apparatus, appropriate subclasses for a molding machine for shaping or reshaping nonmetals combined with means to heat or cool, see subclass 407 and the search notes thereunder.
427, Coating Processes, 457 for coating processes utilizing direct application of electrical magnetic, wave, or particulate energy.
429, Chemistry: Electrical Current Producing Apparatus, Product and Process, subclass 62 for battery having a temperature control and subclass 120 for battery having heat exchange feature.
431, Combustion, 258 for a burner having an electrical heater or igniter.
432, Heating, appropriate subclass for a residual heating apparatus that may include a broadly recited electrical heater as a source of heat.
452, Butchering, subclass 73 for hot wire singers for fowl.
454, Ventilation, especially subclass 83, 93, 121+, and 198 for condensation prevention devices which may use hot or heated air blown on a window or windshield.
606, Surgery, subclass 2.5 for subject matter relating to removal of a calculus (e.g., stone) from the body wherein the calculus is fractured or disintegrated by use of light energy.
901, Robots, subcollection 10 for a robot arm in which a sensor physically contacts and follows the work contour to control the arm movement and subcollection 42 for an art collection of welding robots.
D23, Environmental Heating and Cooling, Fluid Handling and Sanitary Equipment, 314 for heating equipment.

This subclass is indented under the class definition. Subject matter relating to the electrical heating of metal.
(1) Note. The heating in this and indented subclasses is often, but not necessarily, accompanied by working of the metal.
(2) Note. The metal heated is a workpiece and is separable and distinct from the heater, which is a tool. However, heat may be developed within the metal by the passage of electric current.
(3) Note. The heating may be for welding, brazing, soldering, heat treating or other purpose.
(4) Note. The art in miscellaneous subclass 50 relates, for example, to mere heating of metal by the passing of an electric current through it.
(5) Note. Subclasses 7.5, 8.5, 9.5, and 50 to 162 were formed in 1956 by making official some unofficial digests which had been established during the previous two decades by the Examiners of Divisions 37 and 60. A caveat is given: While it is believed that the titles and definitions are reasonably correct, no assurance can be given that all of the
patents, issued prior to the date of reclassification, are in the proper subclass, since the individual patents were not read during the reclassification project. Consequently, in making a thorough search in these subclasses, it is advisable to investigate every subclass which may possibly be pertinent and not, in order to shorten the search, to rely upon the principle of superiority of subclass subject matter because of position in the schedule, since the principle is applicable only in classes where each patent has been analyzed and placed in the schedule in accordance with that portion of the disclosed subject matter which is claimed.

SEE OR SEARCH THIS CLASS, SUBCLASS:
600 for this subject matter where the heating is inductive heating.
678 for microwave heating.
764 for capacitive dielectric heating.

SEE OR SEARCH CLASS:
148, Metal Treatment, particularly subclass 520, 525, and 565 for processes of significant heat treatment of metal to modify or maintain the internal physical structure (i.e., microstructure) or chemical property of metal wherein electrical heating is utilized. See Lines With Other Classes, "Metal Casing, Metal Fusion Bonding, Machining, or Working Classes" to determine what constitutes significant heat treatment.
373, Industrial Electric Heating Furnaces, appropriate subclasses where the metal is heated in an electric furnace.
428, Stock Material or Miscellaneous Articles, subclass 934 for metallic stock produced by an electrical process, and subclass 939 for stock having a molten or fused coating.
483, Tool Changing, generally for a process or apparatus including a tool transfer means combined with either a tool support or storage means. A process or apparatus for electric heating wherein the sole significantly recited feature is changing a tool (e.g., a nonconsumable electrode) is properly classified in Class 483, and may be cross referenced into this class (Class 219, Electric Heating).

This subclass is indented under subclass 50. Subject matter relating to the manufacture of chain link.

SEE OR SEARCH CLASS:
59, Chain, Staple, and Horseshoe Making, 1, and the search notes thereto, for miscellaneous chain making, not involving significant electric heating.

This subclass is indented under subclass 51. Methods.

This subclass is indented under subclass 50. Subject matter relating to the making of rail bonds.
(1) Note. The bond may be for the purpose of furnishing a low resistance electrical shunt around the mechanical joint between rail sections of a railroad track or it may be for the purpose of mechanically uniting rail sections.

This subclass is indented under subclass 53. Subject matter in which the rail bond is made by means of an arc weld.

This subclass is indented under subclass 53. Subject matter relating to resistance welding methods.

SEE OR SEARCH THIS CLASS, SUBCLASS:
53 for resistance welding apparatus for making rail bonds.

This subclass is indented under subclass 50. Subject matter relating to the bonding of wire or bar.
(1) Note. The wire, for example, may be part of a fabric mesh, or the bar may form a grating or a metal window.

SEE OR SEARCH THIS CLASS, SUBCLASS:
156 for mere electric heating of rods or bars.

SEE OR SEARCH CLASS:
140, Wireworking, subclass 112 for this subject matter not having significant welding.

Of wire leads:
This subclass is indented under subclass 56. Subject matter wherein the wire is connected to or from a circuit element.

By microbonding:
This subclass is indented under subclass 56.1. Subject matter wherein the bonding is produced between miniature or microminiature workpieces.

Methods:
This subclass is indented under subclass 56.1. Subject matter including processes of bonding wire leads.

This subclass is indented under subclass 56. Subject matter relating to butt bonding.

SEE OR SEARCH THIS CLASS, SUBCLASS:
101 for miscellaneous butt bonding.

This subclass is indented under subclass 56. Methods.

Of cylinders (e.g., pipes and tubes):
This subclass is indented under subclass 50. Subject matter relating to the bonding of a seam of a cylinder.
(1) Note. The seam may be helical, as in indented subclass 62.

SEE OR SEARCH THIS CLASS, SUBCLASS:
101 for resistance butt bonding of cylindrical shaped tubing.
607 for this subject matter where the heating is inductive.

SEE OR SEARCH CLASS:
413, Sheet Metal Container Making, 58 for the longitudinal seaming of containers, such as cans, where no significant electric heating is involved.

This subclass is indented under subclass 59.1. Subject matter in which the bonding is accomplished by an electric arc.

Tube sheet welding:
This subclass is indented under subclass 60. Subject matter wherein heat exchange tubes are arc butt welded to a perforated plate.

This subclass is indented under subclass 60. Methods.

Having internal support means:
This subclass is indented under subclass 59.1. Subject matter including support means for the cylinder, positioned inside the cylinder during the welding process.

With forming means:
This subclass is indented under subclass 61.1. Subject matter including means for shaping the workpiece.

SEE OR SEARCH THIS CLASS, SUBCLASS:
78.16 for tube sealing apparatus.
91.23 for tube sealing methods.

With cleaning means:
This subclass is indented under subclass 61.1. Subject matter including means to remove excess or undesirable material from the work.

SEE OR SEARCH THIS CLASS, SUBCLASS:
78.14 for work cleaning in bonding with pressure.

With edge guidance means:
This subclass is indented under subclass 61.1. Subject matter including means to direct the path of the edges to be welded through the welding process.

SEE OR SEARCH THIS CLASS, SUBCLASS:
61.3 for edge guidance subject matter without cylinder internal support means.

Utilizing high frequency resistance heating:
This subclass is indented under subclass 59.1. Subject matter wherein the welding apparatus is operated by high frequency current.

With edge guidance means:
This subclass is indented under subclass 59.1. Subject matter including means to direct the path of the workpiece edges through the welding process.

SEE OR SEARCH THIS CLASS, SUBCLASS:
61.13 for this subject matter along with cylinder internal support means.

With adjustable electrode means:
This subclass is indented under subclass 59.1. Subject matter including means to change the position of an electrode used in the welding process.

SEE OR SEARCH THIS CLASS, SUBCLASS:
86.33 for spot bonding adjustable electrodes.
86.8 for interchangeable electrodes.
88 for positioning an electrode along a bus bar.

With condition responsive control of the welding process:
This subclass is indented under subclass 59.1. Subject matter wherein the control means of the welding apparatus responds to a sensed condition.

SEE OR SEARCH THIS CLASS, SUBCLASS:
86.41 for spot bonding with electrode condition responsive control means.
91.1 for spot bonding with condition responsive control
means.
124.1 for automatic positioning of an arc.

Using three or more electrodes:
This subclass is indented under subclass 59.1. Subject matter including the use of three or more electrodes in the welding process.

With cooling means:
This subclass is indented under subclass 59.1. Subject matter including means to maintain or lower the temperature of part or all of the welding apparatus or work.

SEE OR SEARCH THIS CLASS, SUBCLASS:
76.11 for deposition welding with cooling means.
86.31 for spot bonding electrode support with cooling means.
137.62 for consumable electrode gun with cooling means.

This subclass is indented under subclass 59.1. Subject matter in which the longitudinal bond or seam is helical.

This subclass is indented under subclass 59.1. Subject matter having a transformer of which at least a portion rotates in relation with the feed of the workpiece.
(1) Note. The entire transformer, including its secondary terminals and their electrodes may rotate in unison as the electrodes ride along the work, or only a portion of the transformer, such as the secondary and electrodes, may rotate.

SEE OR SEARCH CLASS:
336, Inductor Devices, appropriate subclasses for the structure of rotary transformers, per se.

This subclass is indented under subclass 59.1. Subject matter in which the tube is a container.

SEE OR SEARCH CLASS:
413, Sheet Metal Container Making, 58 for the longitudinal seaming of containers, such as cans, where no significant electric heating is involved.

This subclass is indented under subclass 59.1. Subject matter having nonrotating electrodes.
(1) Note. The electrodes, for example, may oscillate to and from each other with the longitudinally split tube between them.

This subclass is indented under subclass 59.1. Subject matter having at least one electrode inside the cylinder being bonded.
(1) Note. The inside electrode, for example, may be opposed to an exterior electrode, with the current flow between them traversing the region of the cylinder adjacent the longitudinal seam.

SEE OR SEARCH THIS CLASS, SUBCLASS:
64 for this subject matter where the cylinder is a container.

This subclass is indented under subclass 59.1. Resistance heating methods.

This subclass is indented under subclass 50. Subject matter utilized for cutting or disintegrating.
(1) Note. This subclass relates, for example, to the severing of a wire cable by passing a fusing current through a short section thereof, or to the etching of a monogram into the surface of the metal.

SEE OR SEARCH THIS CLASS, SUBCLASS:
19 for similar subject matter not having metallic workpieces as, for example, perforating of paper by sparks and machining of nonmetal by electron beams.

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175, Boring or Penetrating the Earth, subclass 16 for an electrical heating process or device for forming a hole in the earth by directly applying heat to fluidize or comminute the material forming the earth.
205, Electrolysis: Processes, Compositions Used Therein and Methods of Preparing the Compositions, 640 for electrolytic erosion of a workpiece to change the shape or surface configuration thereof.
216, Etching a Substrate: Processes, subclass 75 and 100 for the etching of metal.

Electric arc:
This subclass is indented under subclass 68. Subject matter utilizing a continuous or sustained electric space discharge between an electrode and a work piece.
(1) Note. The disintegrating action of the arc may be assisted, e.g., by a flow of compressed air or oxygen.

SEE OR SEARCH THIS CLASS, SUBCLASS:
121 for this subject matter not utilized for cutting or
disintegrating.

SEE OR SEARCH CLASS:
148, Metal Treatment, subclass 9.5 for using heat to desurface or gorge metal.
204, Chemistry: Electrical and Wave Energy, subclass 224 for apparatus used for electrochemical machining.
266, Metallurgical Apparatus, subclass 48 for flame cutting apparatus.

Electric spark machining:
This subclass is indented under subclass 68. Subject matter utilizing a brief electric space discharge between an electrode and a work piece (i.e., A. C. voltage).
(1) Note. This subclass and the subclasses indented hereunder were formerly unofficial digests. Hence, the placement of documents therein might not reflect schedule hierarchy.

SEE OR SEARCH CLASS:
204, Chemistry: Electrical and Wave Energy, appropriate subclasses for apparatus and methods of electrochemical machining.

Wire cutting:
This subclass is indented under subclass 69.11. Subject matter utilizing a wire electrode for cutting a workpiece.

SEE OR SEARCH THIS CLASS, SUBCLASS:
69.13 for electrical circuits specially adapted to subject matter under subclass 69.1.
69.2 for vibrating a wire electrode during cutting.

SEE OR SEARCH CLASS:
204, Chemistry: Electrical and Wave Energy, subclass 206 for apparatus used in wire cutting use electrochemical machining.

Circuits:
This subclass is indented under subclass 69.11. Subject matter utilizing an electrical circuit specially adapted for cutting or gouging.
(1) Note. The electrical circuit may, for example, be the power supply or a control circuit.

SEE OR SEARCH CLASS:
320, Electricity: Battery or Capacitor Charging or Discharging, 166 for capacitor charging or discharging.
700, Data Processing: Generic Control Systems or Specific Applications, subclasses 159-195 for machining using a numeric controller.

Dielectric composition and purification:
This subclass is indented under subclass 69.11. Subject matter involving a dielectric medium between a workpiece and an electrode and any reuse or purification of the dielectric medium.
(1) Note. The dielectric medium may be a gas or a liquid.
(2) Note. The medium under this definition does not include electrolyte.

SEE OR SEARCH CLASS:
210, Liquid Purification or Separation, appropriate subclasses for liquid purification in general.

Electrodes:
This subclass is indented under subclass 69.11. Subject matter involving an electrode's shape, composition or holder used in an electric arc or electric spark cutting (EDM) operation.

SEE OR SEARCH CLASS:
204, Chemistry: Electrical and Wave Energy, 280 for electrodes used in electrochemical machining.

Gap spacing control:
This subclass is indented under subclass 69.11. Subject matter including apparatus to control the gap distance between an electrode and a workpiece.

SEE OR SEARCH CLASS:
205, Electrolysis: Processes, Compositions Used Therein, and Methods of Preparing the Compositions, 652 for electrolytic erosion of a workpiece to change the shape or surface configuration thereof in which the gap between a tool and a workpiece is either maintained or defined.
318, Electricity: Motive Power Systems, 560 for positional servo systems.

Methods:
This subclass is indented under subclass 69.11. Subject matter including a method of machining specially adapted for treating particular objects or for obtaining special results.

SEE OR SEARCH CLASS:
205, Electrolysis: Processes, Compositions Used Therein, and Methods of Preparing the Compositions, 640 for electrolytic erosion of a workpiece to change the shape or surface configuration thereof.

Pulse:
This subclass is indented under subclass 69.11. Subject matter including a circuit used to shape a particular electric pulse to be applied between an electrode and a workpiece.

Safety circuits:
This subclass is indented under subclass 69.11. Subject matter utilizing a safety circuit in the event of electric arcing or a short circuiting or in the event of danger (e.g., an earthquake or fire).

Vibrating electrodes or workpiece:
This subclass is indented under subclass 69.11. Subject matter wherein the electrode or workpiece is vibrating during machining.
(1) Note. Any movement of the electrode or workpiece during machining will cause vibrationary movement.

SEE OR SEARCH CLASS:
205, Electrolysis: Processes, Compositions Used Therein, and Methods of Preparing the Compositions, subclass 671 for electrolytic erosion of a workpiece to change the shape or surface configuration thereof which provides for agitation or vibration of the electrolyte.

This subclass is indented under subclass 69. Subject matter relating to hand held tools.

SEE OR SEARCH THIS CLASS, SUBCLASS:
138 especially subclass 139, for similar subject matter not utilized for disintegration or cutting.

This subclass is indented under subclass 50. Subject matter in which the metal is heated by means of current flow between it and a surrounding liquid.
(1) Note. The liquid may be quiet, as in a tank, or flowing, as in a jet.

SEE OR SEARCH THIS CLASS, SUBCLASS:
72 for analogous subject matter where the liquid is not used as an electrode.

SEE OR SEARCH CLASS:
204, Chemistry: Electrical and Wave Energy, appropriate subclasses for analogous subject matter utilized for electrochemistry.

This subclass is indented under subclass 50. Subject matter in which a nonatmospheric environment is created at the region of electric heating.
(1) Note. The environment may, for example, be a bath of oil which prevents overheating and oxidation during resistance welding, or it may be a vacuum.

SEE OR SEARCH THIS CLASS, SUBCLASS:
68 for similar subject matter utilized for cutting or disintegrating.
71 for similar subject matter in which a liquid environment acts as an electrode.

SEE OR SEARCH CLASS:
228, Metal Fusion Bonding, 218 for formation of a metallic bond in a nonatomospheric environment wherein heating is other than electrical.

This subclass is indented under subclass 72. Subject matter in which the non-atmospheric environment is slag or a slag forming material.

SEE OR SEARCH THIS CLASS, SUBCLASS:
124.1 for this subject matter in combination with means to automatically position an electric arc.
145.22 145.23 and 146.1+, for mere arc electrodes having fluxing or slagging means.

SEE OR SEARCH CLASS:
314, Electric Lamp and Discharge Devices: Consumable Electrodes, 21 for arc lamps having an auxiliary material
supply to the arc.
501, Compositions: Ceramic, subclass 28 for glass batch forming compositions containing slag.

Including electroslag welding:
This subclass is indented under subclass 73. Subject matter including welding processes wherein coalescence is produced by molten slag which melts the filler metal and the surfaces of the work being welded.

For coating:
This subclass is indented under subclass 73.1. Subject matter wherein at least one layer of weld material is applied to cover a portion of the surface area of a workpiece.

SEE OR SEARCH THIS CLASS, SUBCLASS:
73.21 for submerged arc coating.
76.1 for deposition welding.

With granular flux supply:
This subclass is indented under subclass 73. Subject matter including means for depositing particulate weld protection material.

For deposition welding:
This subclass is indented under subclass 73.2. Subject matter including welding processes wherein coalescence is produced by heating with an arc or arcs between a bare metal electrode or electrodes and the work, with the arc being shielded by a blanket of granular, fusible material on the work.

SEE OR SEARCH THIS CLASS, SUBCLASS:
73.11 for electroslag coating.
76.1 for other deposition welding subject matter.

This subclass is indented under subclass 72. Subject matter in which the nonatmospheric environment is a gas whose composition is not that of air or in which the nonatmospheric environment is compressed or rarified air.
(1) Note. The environment may be formed by the gases liberated by the coating of a "shielded" electrode (e.g., coated electrode) when an arc is struck from the electrode, or by an external gas supply connected to a hand held torch.

SEE OR SEARCH THIS CLASS, SUBCLASS:
122 for this subject matter.

SEE OR SEARCH CLASS:
313, Electric Lamp and Discharge Devices, 231.01 for analogous subject matter, not utilized to heat metal.
314, Electric Lamp and Discharge Devices: Consumable Electrodes, subclass 22 for arc lamps having auxiliary fluent material feed to the arc.
315, Electric Lamp and Discharge Devices: Systems, 111.01 for systems, not utilized to heat metal, analogous to the systems of this subclass.

This subclass is indented under subclass 74. Subject matter in which the electric heating arc is of the nonconsumable electrode type.
(1) Note. This subclass relates, for example, to arc torches utilized in atomic hydrogen welding, in which the tungsten electrodes wear away only slowly.

For deposition welding (e.g., coating or building up):
This subclass is indented under subclass 50. Subject matter relating to the coating or building up of a base by means of deposited metal.

SEE OR SEARCH CLASS:
427, Coating Processes, appropriate subclasses for coating in general.

With cooling means:
This subclass is indented under subclass 76.1. Subject matter including means to maintain or lower the temperature of part or all of the welding apparatus or work.

SEE OR SEARCH THIS CLASS, SUBCLASS:
86.31 for spot bonding electrode support with cooling means.
137.62 for consumable electrode arc welding with cooling means.

Of multiple distinct layers:
This subclass is indented under subclass 76.1. Subject matter wherein the deposited weld material is a composite of separate strata.
(1) Note. The layers are usually, but not necessarily, dissimilar in composition.

By spark discharge:
This subclass is indented under subclass 76.1. Subject matter wherein a mixture of powders and combustible gases is detonated by an electrically produced spark, thereby simultaneously heating the powders and propelling them onto the workpiece surface at very high velocities.

By electric arc:
This subclass is indented under subclass 76.1. Subject matter wherein the welding process includes heating with an electrically produced arc.

SEE OR SEARCH THIS CLASS, SUBCLASS:
121.11 for electric arc welding.

With nonconsumable electrode:
This subclass is indented under subclass 76.14. Subject matter including electrode arc producing means without consumption of the electrode.

Plasma:
This subclass is indented under subclass 76.14. Subject matter wherein coalescence is produced by heating with a constricted arc between an electrode and the work or the electrode and the constricting nozzle, and with shielding obtained from hot ionized gases.

SEE OR SEARCH THIS CLASS, SUBCLASS:
121.36 for other arc plasma heating subject matter.

By resistance heating:
This subclass is indented under subclass 76.1. Subject matter including heating processes wherein coalescence is produced by the heat obtained from resistance of the work to electric current in a circuit of which the work is a part, and by the application of pressure.

SEE OR SEARCH THIS CLASS, SUBCLASS:
53 and 55, for rail bond resistance welding.
59.1 61.1+, 61.2, 61.3, 61.4, 61.5, 61.6, 61.7, and 67 for cylinder resistance heating methods.
78 for other resistance heating subject matter.

This subclass is indented under subclass 76.1. Subject matter in which the part coated or built up is the cutting edge of a tool.

For bonding with pressure (e.g., resistance welding):
This subclass is indented under subclass 50. Subject matter relating to the bonding of metal by means of pressure while heated by the electric current.
(1) Note. The bond is usually, but not necessarily, a metal-to-metal weld.
(2) Note. The heat is generally created by resistance heating, but may, as in the case of indented subclasses 97+, be created by an electric arc.

SEE OR SEARCH THIS CLASS, SUBCLASS:
53 and 55, for rail bond resistance welding.
59.1 61.1+, 61.2, 61.3, 61.4, 61.5, 61.6, and 61.7 for cylinder resistance welding subject matter.
76.17 for deposition welding by resistance heating.
603 for this subject matter where the electric current is induced in the metal by electromagnetic or electrostatic induction.

By solid-state bonding (e.g., diffusion):
This subclass is indented under subclass 78.01. Subject matter wherein the workpiece joint interface coalescence is produced essentially at temperatures below the melting point of the metals being joined, without the addition of a brazing filler metal.

Honeycomb:
This subclass is indented under subclass 78.01. Subject matter wherein the bonded work has the structure or appearance of a honeycomb.

SEE OR SEARCH CLASS:
228, Metal Fusion Bonding, subclass 181 for metal fusion bonding processes for honeycombs.

Methods:
This subclass is indented under subclass 78.11. Subject matter including processes of making honeycombs.

With additional heating device:
This subclass is indented under subclass 78.01. Subject matter including means for heating part or all of the work being welded other than the heating means used principally for accomplishing the welding process.

SEE OR SEARCH THIS CLASS, SUBCLASS:
91.22 for methods of additional heating to the same spot.

With work cleaning means:
This subclass is indented under subclass 78.01. Subject matter including means to remove excess or undesirable material from the work.

SEE OR SEARCH THIS CLASS, SUBCLASS:
61.12 for electric heating of metal cylinders with internal support having cleaning means.

With work cutting means:
This subclass is indented under subclass 78.01. Subject matter including means to sever work during or after the welding process.

SEE OR SEARCH THIS CLASS, SUBCLASS:
124.21 for work cutting with automatic positioning of an electric metal heating arc.

With work deforming means (e.g, tube sealing):
This subclass is indented under subclass 78.01. Subject matter including means for forging or shaping of the work.

SEE OR SEARCH THIS CLASS, SUBCLASS:
61.11 for forming means with the electric heating of cylinders having internal support means.
91.23 for methods of spot bonding with work deforming.

This subclass is indented under subclass 78.01. Subject matter having a conveyer for handling the workpiece.

SEE OR SEARCH THIS CLASS, SUBCLASS:
124.1 and 125.1+, for similar subject matter in arc welding.

SEE OR SEARCH CLASS:
198, Conveyors: Power-Driven, appropriate subclasses (e.g., 373 for a conveyor provided with an orienting device) for power driven conveyors, per se, and consult the search notes for related art.

This subclass is indented under subclass 79. Subject matter in which the bond is a spot bond.

This subclass is indented under subclass 78.01. Subject matter in which the electric current is applied to the metal by roller type electrodes.
(1) Note. The roller electrode may produce a continuous weld or an interrupted weld, consisting of distinct spots.

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

SEE OR SEARCH CLASS:
191, Electricity: Transmission to Vehicles, appropriate subclasses for current collecting and current distributing rollers.
492, Roll or Roller, for a roll, per se, not elsewhere provided for, and see the notes thereunder.

This subclass is indented under subclass 81. Subject matter in which the workpiece is stationary and the roller moves.

This subclass is indented under subclass 81. Methods.

This subclass is indented under subclass 81. Roller electrodes.

Brazing or soldering:
This subclass is indented under subclass 50. Subject matter in which the metal is heated and filler metal is used to produce a weld by means of brazing or soldering.
(1) Note. The filler metal (flux or solder) is to be applied to at least one surface of the metals to be joined.
(2) Note. This subclass and the subclasses indented hereunder were formerly unofficial digests. Hence, the placement of documents therein might not reflect schedule hierarchy.

SEE OR SEARCH THIS CLASS, SUBCLASS:
129 for brazing or soldering where an electric arc (torch) provides the required heat.
615 and 616, for specific means of applying the heat.

SEE OR SEARCH CLASS:
29, Metal Working, for generic brazing and soldering means and methods.

Utilizing radiant energy:
This subclass is indented under subclass 85.1. Subject matter in which the heat is applied to the metal by means of radiant energy (e.g., infrared lamps, resistance heaters, lasers, etc.).

SEE OR SEARCH THIS CLASS, SUBCLASS:
121 for additional metal heating where the radiant energy source is an electron beam or laser.
347 for heat energy reflector means.
523 for the particular structure of resistance heater.

Methods:
This subclass is indented under subclass 85.12. Subject matter including methods of brazing or soldering.

SEE OR SEARCH THIS CLASS, SUBCLASS:
121 for methods of welding metal workpieces by means of electron beam heating or by means of laser heating.

With filler metal in circuit:
This subclass is indented under subclass 85.1. Subject matter wherein the filler metal is melted by the passage of electrical current therethrough.

Methods:
This subclass is indented under subclass 85.14. Subject matter which includes methods of brazing or soldering.

Electrically heated tool (e.g., electrodes, heaters, etc.):
This subclass is indented under subclass 85.1. Subject matter in which the required heat is applied to the metal workpiece by means of a resistance heated tool having a particular structure. Electrical current passes through the tool and produces the heat (e.g., electrodes, heaters, etc.).

SEE OR SEARCH THIS CLASS, SUBCLASS:
119 for the particular structure of an electrode.
229 for a hand-manipulative tool with heated tip or heat applied to localized area.
523 for resistance heater structure.

Furnaces or enclosures:
This subclass is indented under subclass 85.1. Subject matter in which the required heat is applied to the metal by means of a particular furnace or enclosure (e.g., a heating chamber).

SEE OR SEARCH THIS CLASS, SUBCLASS:
388 for oven type enclosures including means whereby the material to be heated may be passed continuously through heated area.
651 for inductively heated furnaces or enclosures.

Wire lead bonders:
This subclass is indented under subclass 85.1. Subject matter wherein the metal workpiece to be joined is wired.

SEE OR SEARCH THIS CLASS, SUBCLASS:
56.1 for the electrical bonding of wire leads.

SEE OR SEARCH CLASS:
228, Metal Fusion Bonding, subclass 4.5 and 904 for miscellaneous wire lead bonders (i.e., bonders which do not necessarily specify electric heating).

Machine for predetermined operation:
This subclass is indented under subclass 85.1. Subject matter in which the required heat and filler metal are applied to the metal workpiece by means of a machine including means for conveying the workpiece and/or positioning the heated tool.

SEE OR SEARCH THIS CLASS, SUBCLASS:
59.1 where the predetermined operation is the welding of pipes or tubes.
79 for electrical heating machines with a conveyor for workpiece.

SEE OR SEARCH CLASS:
228, Metal Fusion Bonding, 4.1 for machines with means to apply the flux, to handle or move the work, and to align and bond the work.

Fluxes or solders:
This subclass is indented under subclass 85.1. Subject matter in which the composition of a filler metal (flux or solder) can be used in a brazing or soldering operation.

SEE OR SEARCH THIS CLASS, SUBCLASS:
146.1 for the composition of a weld rod.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, 122.1 for alloy of metallic compositions; and subclass 257 for flux composition.
148, Metal Treatment, 23 for fluxing compositions.
228, Metal Fusion Bonding, 262.1 for a process of bonding wherein the work component, temperature, or pressure is critical.
420, Alloys or Metallic Compositions, for the particular alloy composition.

Solder preforms:
This subclass is indented under subclass 85.1. Subject matter in which the structure or shape of the filler metal (flux or solder) is predetermined to form the resultant joint (braze or weld).

SEE OR SEARCH THIS CLASS, SUBCLASS:
85.2 and 146.1, for the specific composition of the solder preform.

SEE OR SEARCH CLASS:
228, Metal Fusion Bonding, subclass 56.3 for additional solder forms used in bonding.

Methods:
This subclass is indented under subclass 85.1. Subject matter with miscellaneous methods of brazing or soldering.

By spot bonding:
This subclass is indented under subclass 78.01. Subject matter wherein welding is made between or upon overlapping members, coalescence may start and occur on the faying
surfaces or may have proceeded from the surface of one member, and the weld cross section is approximately circular.
(1) Note. This subclass relates, for example, to spot welding of two overlapped plates where the spot weld is a substitute for a bolt or rivet connection.

SEE OR SEARCH THIS CLASS, SUBCLASS:
56 for spot bonding of wires, rods, or bars.

SEE OR SEARCH CLASS:
140, Wireworking, subclass 112 for nonelectric spot welders utilized to join wire.

With hand-manipulative portable devices:
This subclass is indented under subclass 86.1. Subject matter wherein the bonding apparatus includes structure adapted to manually hold or manipulate the bonding tool or instrument while in use.

With separately applied pressure and heat:
This subclass is indented under subclass 86.1. Subject matter wherein the pressure and heat are not applied simultaneously during the welding process.

With welding pressure controlled by the work support:
This subclass is indented under subclass 86.1. Subject matter wherein the welding pressure is controlled by work support condition responsive means.

SEE OR SEARCH THIS CLASS, SUBCLASS:
86.41 for significant electrode support condition responsive control means.

With work orientation means:
This subclass is indented under subclass 86.1. Subject matter including means for positioning the work with respect to the welding apparatus.

With significant electrode support:
This subclass is indented under subclass 86.1. Subject matter including means to position or orient the welding electrode with respect to the work.

Having cooling means:
This subclass is indented under subclass 86.25. Subject matter including means to maintain or lower the temperature of part or all of the welding apparatus or work.

SEE OR SEARCH THIS CLASS, SUBCLASS:
61.7 for cylinder welding with cooling means.
76.11 for deposition welding with cooling means.

Having magnetic force actuated electrode:
This subclass is indented under subclass 86.25. Subject matter wherein the bonding electrode is controlled by magnetically actuated means during the welding process.

Having adjustment means:
This subclass is indented under subclass 86.25. Subject matter including means to change the position of the electrode.

With condition responsive control means:
This subclass is indented under subclass 86.33. Subject matter wherein the electrode is automatically controlled in response to a sensed condition.

SEE OR SEARCH THIS CLASS, SUBCLASS:
61.15 for cylinder bonding with condition responsive control means.
91.01 for spot bonding with condition responsive control means.
108 for automatic output control circuits.

Responsive to pressure:
This subclass is indented under subclass 86.41. Subject matter wherein the control means is affected by changes in the force applied to the work.

By force balancing:
This subclass is indented under subclass 86.51. Subject matter including means to equalize the welding pressure of plural, simultaneously applied electrodes.

For predetermined welding operation:
This subclass is indented under subclass 86.33. Subject matter wherein the welding process is performed in accordance with a preset schedule of operation.

SEE OR SEARCH THIS CLASS, SUBCLASS:
125.1 for arc welding with predetermined welding operation.

Having interchangeable welding electrodes:
This subclass is indented under subclass 86.25. Subject matter having means for allowing plural electrodes to be used
in place of each other.

For one-face welding:
This subclass is indented under subclass 86.1. Subject matter wherein all electrical welding contact is applied to one side of the work.

This subclass is indented under subclass 86.1. Subject matter in which multiple spot bonds are produced.
(1) Note. The multiple spot bonds can be produced, simultaneously by plural pairs of electrodes.

SEE OR SEARCH THIS CLASS, SUBCLASS:
81 for this subject matter where the multiple bonds are produced by roller type electrodes.

This subclass is indented under subclass 86.1. Subject matter having fixed bus bars of extended length for supplying the heating current and having electrodes for transferring the current to the work, said electrodes being movably positioned along the bus bar.
(1) Note. The bus bars, for example, may serve as backing members for absorbing mechanical thrust produced when the electrodes are clamped to the workpiece.

SEE OR SEARCH CLASS:
191, Electricity: Transmission to Vehicles, 43 for trolleys for transferring electric current from a stationary conductor to a movable load.

This subclass is indented under subclass 86.1. Subject matter in which the electrode is actuated by fluid pressure means.
(1) Note. The electrode may, for example, have a hydraulic cylinder attached to it to obtain a high clamping or indenting force.

SEE OR SEARCH THIS CLASS, SUBCLASS:
418 Rotary Expansible Chamber Devices, appropriate subclasses for rotary expansible chamber type pumps or motors, per se.

SEE OR SEARCH CLASS:
91, Motors: Expansible Chamber Type, appropriate subclasses, for miscellaneous fluid pressure actuated motors.

This subclass is indented under subclass 86.1. Subject matter in which opposing electrodes are mounted on the jaws of a plier or tong.

With condition responsive control of the welding process:
This subclass is indented under subclass 86.1. Subject matter wherein the spot bonding process is automatically controlled in response to a sensed condition.

SEE OR SEARCH THIS CLASS, SUBCLASS:
61.5 for cylinder bonding with condition responsive control means.
86.41 for spot bonding electrode support condition responsive means.
108 for automatic output control circuits.

Methods:
This subclass is indented under subclass 86.1. Subject matter including processes of spot bonding.

Of welding through insulation:
This subclass is indented under subclass 91.2. Subject matter including the processes of bonding through material through which essentially no current will flow.

SEE OR SEARCH THIS CLASS, SUBCLASS:
92 for methods of welding current limitation including interposed insulation.

With additional heating to same spot:
This subclass is indented under subclass 91.2. Subject matter including means to apply heat more than once to same area of the work.

SEE OR SEARCH THIS CLASS, SUBCLASS:
78.13 for additional heating devices.

With work deforming:
This subclass is indented under subclass 91.2. Subject matter including means for forging or shaping of the work.

SEE OR SEARCH THIS CLASS, SUBCLASS:
61.11 for forming means with the electric heating of cylinders having internal support means.
78.16 for forming means with resistance welding.

This subclass is indented under subclass 91.2. Subject matter in which the heating current is made to localize at particular points of the workpiece by means other than the electrodes.
(1) Note. The workpieces to be bonded, for example, may be
coated with insulating paint on the contacting faces except at those points where bonding is to take place.

This subclass is indented under subclass 92. Subject matter in which the current localizing means comprises localized projections on the workpiece.

This subclass is indented under subclass 92. Subject matter in which the current localizing means comprises a member which is interposed between either the workpiece and electrode or between the workpieces being bonded, said member becoming part of the bond.

This subclass is indented under subclass 78.01. Subject matter in which the members to be bonded are brought together percussively to developed the bonding pressure.

SEE OR SEARCH CLASS:
428, Stock Material or Miscellaneous Articles, subclass 940 for metallic stock comprising components bonded by percussive or explosive-type force.

This subclass is indented under subclass 95. Methods.

This subclass is indented under subclass 78.01. Subject matter in which the metal workpieces to be bonded are heated
by an electric arc created between them before pressure is applied.
(1) Note. The metal workpieces may or may not be further heated, after pressure is applied, by means of resistive heating arising from current flowing through the workpiece.

SEE OR SEARCH THIS CLASS, SUBCLASS:
95 for this subject matter in which the pressure is developed percussively.

This subclass is indented under subclass 97. Subject matter in which the metal workpiece is a stud which is bonded to a base.

This subclass is indented under subclass 98. Methods.

This subclass is indented under subclass 97. Methods.

This subclass is indented under subclass 78.01. Subject matter in which the bond is a butt joint between the end of a member and another member.

SEE OR SEARCH THIS CLASS, SUBCLASS:
95 for this subject matter using percussively developed pressure.
97 for this subject matter in which the heat is developed by an electric arc.

SEE OR SEARCH CLASS:
156, Adhesive Bonding and Miscellaneous Chemical Manufacture, 304.1 for processes of butt joining nonmetallic elements.

This subclass is indented under subclass 101. Subject matter in which the bond is an extended seam.
(1) Note. Two narrow sheets of metal, for example, may be edge bonded to form a wide sheet.

SEE OR SEARCH THIS CLASS, SUBCLASS:
81 for similar subject matter utilizing roller electrodes.

This subclass is indented under subclass 101. Subject matter in which one workpiece only is fed to develop the bonding pressure.

This subclass is indented under subclass 101. Methods.

SEE OR SEARCH CLASS:
428, Stock Material or Miscellaneous Articles, 615 for composite metallic stock comprising welded joints characterized by the composition of the parts joined and/or the filler metal.

This subclass is indented under subclass 104. Subject matter relating to the preparation of the edges to be bonded.
(1) Note. The edges, for example, may be preshaped.

SEE OR SEARCH THIS CLASS, SUBCLASS:
73 for arc welding with flux.

SEE OR SEARCH CLASS:
228, Metal Fusion Bonding, appropriate subclasses for metallurgical bonding by nonelectrical heating; particularly 141.1 when combined with work shaping; and subclasses 203+ when combined with other pretreating of the work.

This subclass is indented under subclass 104. Subject matter in which a bridging member is utilized in bonding the butt joint.

This subclass is indented under subclass 104. Subject matter relating to the bonding of an edge or end to a surface.

This subclass is indented under subclass 78.01. Subject matter relating to the system for supplying the electric current which produces the heating.

SEE OR SEARCH THIS CLASS, SUBCLASS:
130.1 for similar subject matter used in arc welding.

SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems, for miscellaneous voltage or current control systems.

This subclass is indented under subclass 108. Subject matter having indicating means.
(1) Note. The indicator may be, for example, a signal, alarm or recorder.

SEE OR SEARCH CLASS:
324, Electricity: Measuring and Testing, appropriate subclasses for electric testing. Note 76.11 for electric meters.
340, Communications: Electrical, subclass 655 for a condition responsive system indicating heating circuit energization.

This subclass is indented under subclass 108. Subject matter which is controlled in response to current in, voltage at or temperature of the workpiece.

SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems, subclasses 234-298 for automatically controlled voltage or current regulation systems.

This subclass is indented under subclass 108. Subject matter wherein the current is repeated or interrupted automatically.
(1) Note. This subclass relates, for example, to systems where the current is interrupted so as to give alternate periods of heating and cooling at the same weld, and to systems where the current is interrupted so that it may be distributed to different weld areas.

SEE OR SEARCH THIS CLASS, SUBCLASS:
81 for roller electrode bonding, some of which utilize interrupted current supply systems.

This subclass is indented under subclass 108. Subject matter
in which the heating current is derived from a stored energy source.
(1) Note. The stored energy source, for example, may be an inductor with a large flux in its core or it may be a storage battery.

SEE OR SEARCH CLASS:
315, Electric Lamp and Discharge Devices: Systems, 289 for miscellaneous space discharge tube systems having a surge generator, and consult the search notes thereto for related art.
320, Electricity: Battery or Capacitor Charging or Discharging, appropriate subclass for charging or discharging a battery or capacitor energy storage system.

This subclass is indented under subclass 112. Subject matter having a condenser to store the energy.

SEE OR SEARCH CLASS:
320, Electricity: Battery or Capacitor Charging or Discharging, appropriate subclasses for charging or discharging a battery or capacitor energy storage system, especially 166 for capacitor charging or discharging.

This subclass is indented under subclass 108. Subject matter having a space discharge control tube.
(1) Note. The tube may be, for example, an ignitron or thyratron.

SEE OR SEARCH CLASS:
315, Electric Lamp and Discharge Devices: Systems, 246 for miscellaneous gas tube systems having alternating current supply and consult the search notes thereto for related art.
323, Electricity: Power Supply or Regulation Systems, subclass 291 for miscellaneous space discharge tube type voltage or current control systems.

This subclass is indented under subclass 108. Subject matter having means to energize or deenergize the system in timed relation to the voltage oscillation of an alternating current supply system.
(1) Note. Switching may be accomplished, for example, only at the voltage or current zero, or in such a manner as not to cause saturation of a transformer.

This subclass is indented under subclass 108. Subject matter having a transformer.

SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems, subclass 355 for miscellaneous transformer systems.
336, Inductor Devices, appropriate subclasses, for transformers, per se.

Methods:
This subclass is indented under subclass 78.01. Subject matter comprising processes of electric heating of metal for bonding with pressure.

SEE OR SEARCH THIS CLASS, SUBCLASS:
78.12 for resistance welding methods of making honeycombs.

This subclass is indented under subclass 117.1. Subject matter involving a particular metal.
(1) Note. This subclass relates, for example, to the welding of dissimilar metals, and to the welding of aluminum, titanium and molybdenum.

SEE OR SEARCH CLASS:
428, Stock Material or Miscellaneous Articles, subclass 650 for a metallic composite in which a component has an aluminum base.

This subclass is indented under subclass 78.01. Subject matter relating to the electrodes utilized in pressure welding.

SEE OR SEARCH CLASS:
439, Electrical Connectors, appropriate subclasses for terminals.

This subclass is indented under subclass 119. Subject matter having cooling means for the electrode.

SEE OR SEARCH CLASS:
313, Electric Lamp and Discharge Devices, 11 for analogous subject matter in the electric lamp and space discharge device art.
439, Electrical Connectors, subclass 112 for cooled terminals.

By Arc:
This subclass is indented under subclass 50. Subject matter where a working arc of charged particles is caused to impinge on a workpiece.

Using electron beam:
This subclass is indented under subclass 121.11. Subject
matter wherein the working arc is an electron beam in a vacuum.

SEE OR SEARCH CLASS:
250, Radiant Energy, subclass 492.1 for irradiation of objects or material and subclass 492.2 for irradiation of semiconductive devices.

Welding:
This subclass is indented under subclass 121.12. Subject matter for joining two workpieces.

Methods:
This subclass is indented under subclass 121.13. Subject matter including methods of joining two workpieces.

Deposition (e.g., sputtering):
This subclass is indented under subclass 121.12. Subject matter wherein an electron beam impinges on a workpiece to evaporate material therefrom.

Melting:
This subclass is indented under subclass 121.12. Subject matter wherein the electron beam liquifies the workpiece.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, subclass 65 for nonferrous electron beam melting processes.
373, Industrial Electric Heating Furnaces, subclass 10 and 11 for an electron beam furnace device.

Methods:
This subclass is indented under subclass 121.16. Subject matter including methods of liquifying a workpiece.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, subclass 65 for nonferrous electron beam melting processes.
373, Industrial Electric Heating Furnaces, subclass 10 and 11 for an electron beam furnace device.

Cutting:
This subclass is indented under subclass 121.12. Subject matter wherein a workpiece is severed by an electron beam.

Etching or trimming:
This subclass is indented under subclass 121.18. Subject matter wherein the cut is superficial or partially through the workpiece.

SEE OR SEARCH CLASS:
216, Etching a Substrate: Processes, subclass 63 and 94 for the use of an election beam in etching.
438, Semiconductor Device Manufacturing: Process, particularly subclass 661 for combined processes for trimming a conductive pathway on a semiconductive substrate.

Methods:
This subclass is indented under subclass 121.19. Subject matter including processes of cutting a workpiece.

Chamber:
This subclass is indented under subclass 121.12. Subject matter wherein an evacuated housing structure is provided for partially or completely enclosing the workpiece.

Sealing:
This subclass is indented under subclass 121.21. wherein vacuum or subatmospheric pressure securing means is provided on the chamber.

Monitoring:
This subclass is indented under subclass 121.21. Subject matter wherein means are provided for visual or electronic communication with the interior of the chamber.
(1) Note. Communication includes such things as microscope and T.V. view.

Nonvacuum environment:
This subclass is indented under subclass 121.12. Subject matter wherein the working electron beam is in the ambient atmosphere.

Shaping:
This subclass is indented under subclass 121.12. Subject matter wherein the working are of the charged particle beam is geometrically configured by using a plate, mask electromagnetic lens electrostatic and electromagnetic deflectors.

SEE OR SEARCH CLASS:
250, Radiant Energy, subclass 396 for focusing and magnetic lenses.
373, Industrial Electric Heating Furnaces, subclass 14 for deflection control.

With focusing:
This subclass is indented under subclass 121.25. Subject matter wherein the location of the charged particle beam is directed to a particular location by focusing (e.g., dynamic of static coil means).

SEE OR SEARCH CLASS:
250, Radiant Energy, subclass 396 for beam focusing.

With electrode or gun structure:
This subclass is indented under subclass 121.25. Subject matter wherein a particular electrode configuration is provided or a particular electron beam generator housing structure is set forth.

SEE OR SEARCH CLASS:
373, Industrial Electric Heating Furnaces, subclass 13 for electron beam gun assembly.

Position control:
This subclass is indented under subclass 12