This is the residual class concerned with the driving of a load by the conversion of heat, pressure, radiant, or gravitational energy into mechanical motion. It includes a motor in combination with its energy supply or its exhaust treatment. It also includes the motors, per se, combinations of motors, and elements specialized for use in such energy conversion that are not specifically provided for elsewhere.
(1) Note. The mere nominal inclusion with the motor of and element or machine driven by the motor is not generally considered sufficient to exclude the patent from the class.

LINES WITH OTHER CLASSES AND WITHIN THIS CLASS
Unless specifically provided for elsewhere, a combination of plural motors of types that would, per se, be classified in different classes is classified in Class 60.
Combustion products generators in which steam or water are added to the combustion zone are classified in Class 60, Power Plants, where it is the sole disclosure that the products of combustion are to be used to produce useful work. See Class 110, Furnaces, and Class 431, Combustion, for combustion products generators of general utility where steam or water is supplied to the combustion zone. Combustion products generators, per se, using solid fuel, having high pressure generator structure peculiar to the generation of high pressure fluid for motive power, are classified herein. Combustion chamber structure of general utility, and structure for fuel preparation and fuel feeding to a conventional combustion chamber not provided for in other fuel preparation classes, as Class 241, Solid Material Comminution or Disintegration, are classified in Class 110, Furnaces.
Combustion product generators in which hazardous or toxic waste is used as the fuel to produce useful work. See Class 588 for the processes of destruction or containment of hazardous or toxic waste.
LINE WITH CLASS 91 AND CLASS 418
See (4) Note of the class definition of Class 91, for a statement of the line between Classes 60 and 91, the same line being maintained between Classes 60 and 418.

REFERENCES TO OTHER CLASSES

SEE OR SEARCH CLASS:
73, Measuring and Testing, appropriate subclass for a measuring and testing device in which the measuring or testing means uses pressurized motive fluid that drives an
indicator.
74, Machine Element or Mechanism, subclass 16 for power tables or strands comprising portable power units.
91, Motors: Expansible Chamber Type, appropriate subclass for a fluid motor or a combination of such motors that has no more than a nominal pressure fluid source or nominal exhaust means. See (4) Note of the class definition of Class 91 for the line between Class 60 and Class 91.
92, Expansible Chamber Devices, appropriate subclass for an expansible chamber device or plural expansible chamber devices. See (4) Note of the class definition of Class 92 for the line between Classes 60 and 92.
122, Liquid Heaters and Vaporizers, for a liquid heater or vaporizer that generates hot fluid. The minimal inclusion of a motor as the source or utilizer of the treated fluid does not prevent classification in Class 122.
123, Internal-Combustion Engines, appropriate subclass, for an internal combustion engine, per se. A combination of internal combustion engines or an internal combustion engine with an exhaust treating or handling means is in Class 60.
173, Tool Driving or Impacting, appropriate subclass for subject matter directed to driving or impacting a tool when such subject matter includes combined features peculiar to tool driving, but which does not include features limiting the subject matter to a specific tool art, such as specific shape of the work contacting portion of a tool, related tools, or an opposed work support. A combination of plural motors of the same or different types, one of which causes or controls tool advance and the other drives or impacts a tool is classified in Class 173.
185, Motors: Spring, Weight, or Animal Powered, appropriate subclass for a spring, weight or animal powered motor and for plural or composite motor combinations consisting solely of arrangements of such motors. See the notes in the class definition of Class 185 for a statement of the line between Classes 60 and 185.
237, Heating Systems, appropriate subclass for a power plant combined with a heating system.
252, Compositions, appropriate subclasses particularly 67 and 71+ for power transmission compositions. Patents are placed in Class 252, Compositions, (1) claiming admixtures of ingredients, or claiming an old compound, limited to use as a hydraulic or other type power transmission fluid, (2) processes of power generation claimed broadly and distinguished solely by the composition or compound used, and (3) power plant apparatus distinguished by the composition of compound therein, i.e., where characteristics of apparatus structure are not claimed. The preceding are placed in Class
252, Compositions, even though freezing or boiling points, temperatures of use, or amount of power transmitted are specified.
290, Prime-Mover Dynamo Plants, appropriate subclass for the combination of a motor and an electric generator in which is included (1) any detail of the generator; (2) any relationship between a generator part and a motor; and (3) any control of the motor by part of the electricity produced by the generator. A motor electric generator combination in combination in which the electric generator is merely a nominal load driven by the motor is not precluded from Class 60.
303, Fluid-Pressure and Analogous Brake Systems, appropriate subclass, for the distribution of fluid to brake motors. See the notes to the definition of subclass 533 of Class 60 for a detailed statement of the line between Classes 60 and 303.
310, Electrical Generator or Motor Structure, appropriate subclass for an electric motor, per se.
318, Electricity: Motive Power Systems, appropriate subclass for a system of electrical supply or control for one or more electrical motors. A residual system comprising an electrical and a nonelectrical motor is in Class 60.
374, Thermal Measuring and Testing, 187 for temperature measurement in which the expansion or contraction of a sensing material drives an indicator.
415, Rotary Kinetic Fluid Motors or Pumps, appropriate subclass for (1) a rotary kinetic energy motor, per se, or one with a merely nominal load, motive fluid supply, or exhaust structure; (2) for a plurality of such motors. See the detailed statement of the line between Classes 60 and 415 in the class definition of Class 415, particularly the search class notes to Class 60 in References to Other Classes.
416, Fluid Reaction Surfaces (i.e., Impellers), appropriate subclass for a motor comprising an unconfined impeller driven by a flowing working fluid, e.g., windmill etc.
418, Rotary Expansible Chamber Devices, appropriate subclass for an expansible chamber fluid motor or a combination of such motors. See Lines With Other Classes and Within This Class, above, for the line between Class 418, Class 60, and an additional class.
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the use of a hazardous or toxic waste as a fuel for power production combined with the destruction of the waste.

This subclass is indented under the class definition. Plants or processes having means to generate combustion products, either continuously or intermittently, whereby said products are usable, at least in part, to perform useful work.
(1) Note. Combustion products generator a device including essentially a chamber in which a suitable fuel and an oxidizer are burned or exploded to produce hot products of combustion, together with accessory means to mix water, fuel and oxidizer, to spray or feed water, fuel, or oxidizer, to ignite the fuel charge, to periodically operate the inlet and exhaust valves, or other means accessory to such chamber.
Continuous combustion type this refers to the operation of a combustion products generator, without cyclically actuated inlet or outlet valves, in which the fuel and oxidizer are supplied to permit combustion to proceed in an unbroken or uninterrupted manner to produce a steady stream of combustion products. This type is also known as a "constant pressure" type.
Intermittent combustion type - this refers to the operation of a combustion products generator, usually having inlet or outlet valves, or both, or their equivalents, in which a fuel charge is periodically exploded or burned to discharge a pulsating stream of combustion products. This type is also known as an "explosion" or "constant volume" type.
(2) Note. This subclass and the indented subclasses include subcombinations peculiarly adapted for power production or solely disclosed for such purpose, unless classification is provided therefor in some other existing class and subclass.
(3) Note. See Lines With Other Classes in the class definition for line between Class 60 and Classes 110 and 431.

SEE OR SEARCH THIS CLASS, SUBCLASS:
272 for internal-combustion engines which discharge exhaust gases under pressure suitable for use in a motor, in combination with means to act upon the exhaust gases, such as means to store or to conduct such gases, or to add a fluid thereto, or to burn fuel in said exhaust gases.
597 for plants in which the combustion products are generated by burning a fuel in the expansible working chamber of an internal combustion engine.

SEE OR SEARCH CLASS:
102, Ammunition and Explosives, subclass 202 for means for
igniting a missile propellant.

This subclass is indented under subclass 39.01. Processes for producing motive fluids composed of products of combustion or for operating plants utilizing such motive fluids.

SEE OR SEARCH CLASS:
48, Gas: Heating and Illuminating, subclass 212 for processes wherein oil and air are injected into a heated retort.
252, Compositions, 372 for processes of making gaseous compositions involving combustion.
264, Plastic and Nonmetallic Article Shaping or Treating: Processes, subclass 30 for processes of furnace lining formation or repair and see the notes thereto.
431, Combustion, 2 for a residual process of combustion or burner operation of general application.

This subclass is indented under subclass 39.02. Processes involving the variation of the quantity or temperature of the motive fluid composed of products of combustion, or the available energy of a plant utilizing such motive fluid.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.2 for apparatus involving regulation of power output in a combustion products power plant.

This subclass is indented under subclass 39.02. Processes involving the generation of motive fluid composed of products of combustion used in, or the use of such motive fluid in, plants having multiple expansion motors.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.16 for apparatus involving reexpansion of the combustion products in multiple motor plants, and see the search notes thereunder.

This subclass is indented under subclass 39.02. Processes involving the addition of steam and/or water to the ingredients utilized to generate the motive fluid, or to the motive fluid, prior to its discharge from the motor.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.53 for apparatus involving the addition of steam and/or water to the motive fluid.

SEE OR SEARCH CLASS:
48, Gas: Heating and Illuminating, subclass 215 for processes wherein oil, steam and air are injected into a highly heated retort.

This subclass is indented under subclass 39.02. Processes involving the initiation of the combustion of the fuel charge and/or the injection of the fuel within a combustion products generator.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.14 for starting devices.
39.74 for fuel injection apparatus for combustion products generators.
39.82 for ignition devices for combustion products generators.

This subclass is indented under subclass 39.01. Plants in combination with means whereby the device, in addition to providing useful power for external use, also serves as a
source of heat or pressure fluid, such as steam, combustion products, or compressed air, for use in another art device.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.13 39.14, 39.15+, and 39.19, for plants in which the supplemental pressure fluid, as defined above, is used in another motor.

This subclass is indented under subclass 39.01. Plants in combination with means to supply a lubricant to movable parts thereof.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, subclass 196 for lubrication means for internal-combustion engines.
184, Lubrication, appropriate subclass, for lubrication in general.

With safety device:
This subclass is indented under subclass 39.01. Plants in combination with a safety device in the form of means to prevent the creation of dangerous or objectionable operating conditions, or to sense and to relieve such conditions.
(1) Note. The conditions referred to do not ordinarily occur during normal operation of the power plants.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.03 for processes of regulation of the rate of power output.
39.13 for plants wherein the operation of the generator is stopped and started in response to pressure changes in an accumulator receiving products of combustion.
39.2 for apparatus for the regulation of the rate of power output.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, subclass 198 for safety devices designed for use with internal-combustion engines.

Debris anti-ingestion preventer:
This subclass is indented under subclass 39.091. Plants wherein the safety device comprises structure designed to prevent the inflow of foreign material into the air intake or other sensitive structure of the power plant.

SEE OR SEARCH CLASS:
55, Gas Separation, subclass 306 for debris anti-ingestion means for use on aircraft engine inlets not combined with significant engine structure.

Ice preventer or deicer:
This subclass is indented under subclass 39.091. Plants wherein the safety device comprises structure designed to either prevent the formation or eliminate the accumulation of frozen water on components of the power plant.

Fuel flusher or drainer:
This subclass is indented under subclass 39.091. Plants wherein the safety device comprises structure designed to either purge a portion of the fuel system of the power plant or to remove areas of abnormally accumulated fuel in the power plant.

This subclass is indented under subclass 39.09. Plants in which the safety means senses an excess pressure in the system, and relieves such excess pressure.

SEE OR SEARCH CLASS:
137, Fluid Handling, 455 for valves which respond to changes in line condition.
220, Receptacles, subclasses 89.1-89.4 for frangible or
fusible diaphragms which burst or melt to relieve excess pressure.

This subclass is indented under subclass 39.09. Plants in which the safety means includes screens or equivalent means to prevent the flash-back of the flame.

SEE OR SEARCH CLASS:
48, Gas: Heating and Illuminating, subclass 192 for safety devices for preventing, localizing and confining explosions in a gas distributing system.
123, Internal-Combustion Engines, subclass 434 for safety devices used in connection with charge-forming devices of internal-combustion engines.
220, Receptacles, 88.1 for flame guards for receptacles.
222, Dispensing, subclass 189.01 for flame guards for dispensers.

This subclass is indented under subclass 39.01. Plants in combination with means, distinct from and independent of the combustion products generator, to generate a combustible gas that is delivered to the combustion products generator to be burned.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.69 for combinations wherein the generator of the combustible gas is not distinct from the combustion products generator, but functions merely as a pre-combustion chamber.
39.71 for means to vaporize a liquid fuel by heat incidental to the operation of the combustion products generator.

SEE OR SEARCH CLASS:
48, Gas: Heating and Illuminating, appropriate subclasses for combustible gas generators, per se.
123, Internal-Combustion Engines, subclass 3 for combinations of an internal-combustion engine and a combustible gas generator.

This subclass is indented under subclass 39.01. Plants including means to start and stop the operation of the combustion products generator in response to pressure change in a storage vessel.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.141 for starting devices.
39.24 for plants in which the operation of the combustion products generator is varied, but not stopped, in response to pressure fluctuations in the combustion products accumulator.
281 for combinations of internal-combustion engines and exhaust gas accumulators.

With starting device:
This subclass is indented under subclass 39.01. Plants in combination with means to initially place the plant in operation, or to condition the plant or to modify the normal operating cycle, in order to facilitate the initial operation thereof.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.13 for plants which automatically start and stop the operation of a combustion products generator in response to the pressure in an accumulator for combustion products.
39.33 for means to convert the cycle of operation from one type to another, or to operate on different fluids, selectively, for normal power delivery.
39.821 for ignition devices which may or may not be used only during starting.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, 179.1 for starting devices for internal-combustion engines.

Separate starting device or motive fluid source:
This subclass is indented under subclass 39.141. Plants having either (1) a motor distinct from a plant wherein the motor is used to place the plant in operation, or (2) a separate source of working fluid distinct from a main source of working fluid normally used to drive the plant wherein this separate source of fluid is used to place the plant in operation.

This subclass is indented under subclass 39.01. Plants having a plurality of distinct motors, at least two of which are operated by a fluid under pressure.
(1) Note. Distinct motors include (1) two or more turbine rotors on a common shaft receiving combustion products, in parallel, from a common combustion products generator, or each rotor being supplied by a separate combustion products generator; (2) two or more expansible chamber cylinders supplied, in parallel, from a common combustion products generator where the cylinders are more than mere duplicates of each other; (3) a plurality of motors, on separate shafts, which may or may not deliver power to a common output shaft; (4) a plurality of turbine stages in a common housing, or in separate housings, wherein the combustion products pass through the stages in series, involving some treatment of the combustion products between stages; and (5) two or more turbines with means whereby the turbines are selectively operable to rotate power output shaft in either direction. The means whereby the turbines are selectively operable may include one or more clutches or equivalent means to connect the turbines to the power output shaft.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.141 for starting motors used with plants operated by products of combustion.
39.22 for plants in which an auxiliary motor controls the cycle frequency of an intermittent combustion type of combustion products generator.
698 for motors having several modes of operation, each classifiable in different motor classes, or for multiple motors of the same class other than combustion products types.

SEE OR SEARCH CLASS:
415, Rotary Kinetic Fluid Motors or Pumps, appropriate
subclasses for plural or multiple-stage gas turbines, per se, that does not involve combustion products generation means.

Re-expansion:
This subclass is indented under subclass 39.15. Plants in which the motive fluid passes through two or more motors in series.

SEE OR SEARCH CLASS:
91, Motors: Expansible Chamber Type, subclass 8 and 152 for multiple expansion type expansible chamber motors.
418, Rotary Expansible Chamber Devices, subclass 5 for multistage rotary expansible chamber device.

Counter-rotatable:
This subclass is indented under subclass 39.161. Plants in which two motors rotate in different directions.

Selectively connectable:
This subclass is indented under subclass 39.161. Plants having at least two motors which may be selectively interconnected to provide a common power output.

This subclass is indented under subclass 39.16. Plants including means to treat the combustion products between successive stages of expansion, as, for example, by heating, cooling, or by the addition of fuel air, water, steam or more combustion products.

SEE OR SEARCH THIS CLASS, SUBCLASS:
643 and 662, for multiple stage motor plants using mixed fluids other than products of combustion, having means for admitting fluid between expansion stages from some source
other than the next preceding stage while fluid is being admitted from the preceding stage.
648 677, 679, and 684, for multiple stage motors using motive fluid other than products of combustion, including means affecting the motive fluid between stages, as, for example, (1) tapping fluid for external use, (2) reheating, or (3) separation of condensate.

SEE OR SEARCH CLASS:
91, Motors: Expansible Chamber Type, 8 for multiple expansion type expansible chamber motors having means for permitting a subsequent pressure stage to receive motive fluid other than that discharged from the immediately prior stage, said prior stage also receiving motive fluid and at least ultimately discharging it into said subsequent stage.

Different fluids:
This subclass is indented under subclass 39.15. Plants in which unlike motive fluids are utilized in the several motors, at least one of such motive fluids being composed of combustion products.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.14 for starting motors using a motive fluid other than combustion products.

Steam and combustion products:
This subclass is indented under subclass 39.181. Plants having at least one motor operating on steam and one motor operating on combustion products.

Air and combustion products:
This subclass is indented under subclass 39.181. Plants having at least one motor operating on air and one motor operating on combustion products.

This subclass is indented under subclass 39.01. Plants having a single motor in which two or more unlike motive fluids are simultaneously employed without being mixed in the motor, at least one of the motive fluids being composed of combustion products.

SEE OR SEARCH THIS CLASS, SUBCLASS:
486 and 674, for power plants simultaneously using two or more different motive fluids in a single motor, the motive fluids being other than combustion products.

This subclass is indented under subclass 39.01. Plants in combination with means to vary the rate of power output, as by varying the speed of the power output motor, or by controlling the temperature and/or quantity of the motive fluid, or by varying the duration of the events, during each cycle, of an intermittent combustion type generator.
(1) Note. In order to be classified in this subclass the patent should claim the control means more specifically than merely as a "valve", "valved pipe", "controlling means", "throttle valve", or similar broad terms. This exclusion note applies only to this subclass, and not to the indented subclasses.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.03 for processes of regulation of power output.
39.13 for regulation involving the starting and stopping of the combustion products generator in response to pressure changes in a storage vessel receiving such products.

SEE OR SEARCH CLASS:
110, Furnaces, 101 for devices for feeding solid fuel to furnaces.
123, Internal-Combustion Engines, 319 for speed regulators for internal-combustion engines.

This subclass is indented under subclass 39.2. Combinations in which the quantity of the motive fluid is regulated by varying the number of combustion products generators in operation, viz., by cutting in and out one or more, but not all, of a plurality of combustion products generators.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.09 for combinations in which the operation of all combustion products generators is discontinued upon the creation of, or to prevent the creation of, dangerous operating conditions.
39.14 for starting arrangements of plants having a number of combustion products generators, wherein a fewer number than all of the generators are placed in operation during the starting cycle.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, subclass 52 for systems for disabling some of the cylinders of an internal-combustion engine in order to vary the power output.

This subclass is indented under subclass 39.2. Combinations in which the quantity of the motive fluid is regulated by varying the cycle frequency of operation of an intermittent combustion type generator relative to the speed of the prime mover, i.e., the power output motor.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.13 for an independent motor for feeding a combustion products generator, the motor being started and stopped in response to the pressure in an accumulator receiving the combustion products.

With variable oxidizer control:
This subclass is indented under subclass 39.01. Plants having means to vary the rate of flow of oxidizer to the combustor, either for regulating the combustion process or for regulation of the engine power output.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.29 for automatic or condition responsive control of
oxidizer.

This subclass is indented under subclass 39.2. Combinations including means to sense a change in condition of power plant operation, wherein the means to vary the rate of power output is under the control of such sensing means.
(1) Note. Control means responsive to (1) pressure and/or temperature of air or combustion products at any point between entrance into the compressor and discharge from the power plant; or (2) rate of flow or quantity of (a) air passing through the compressor to the combustion products generator or (b) products of combustion has been regarded as responsive to a change in condition of power plant operation.
The following has not been deemed significant power plant structure; control means responsive to (1) power plant speed; (2) carburetor or compressor inlet pressure; (3) air inlet temperature to carburetor or compressor; (4) pump speed; (5) fuel inlet or discharge pressure, velocity or volume; (6) altitude.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.09 for combinations of power plants with means to discontinue the supply of oxidizer, fuel, water, or motive fluid in response to some undesired or dangerous condition of operation.
233 for a means controlling the thrust of a thrust producing device responsive to a motor condition such as speed, thrust, acceleration, etc.

SEE OR SEARCH CLASS:
137, Fluid Handling, 16 for a residual prime mover control system.
236, Automatic Temperature and Humidity Regulation, subclass 14 and 15, for automatic furnace control.
431, Combustion, 18 for a residual automatically controlled device specialized to combustion and disclosed for use for purposes other than for external power.
701, Data Processing: Vehicles, Navigation, and Relative Location, subclass 99 and 100 for indication or control of power plants, particularly gas turbine compressors.

This subclass is indented under subclass 39.24. Combinations wherein the means to vary the rate of power output regulates the rate of flow of motive fluid to the prime mover, i.e., external power output motor.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.15 for plants having a plurality of distinct motors wherein means are provided to vary the rate of flow of motive fluid to one or more motors.

This subclass is indented under subclass 39.24. Combinations wherein the means to vary the rate of power output regulates the quantity of oxidizer, fuel and water or steam, comprising the ingredients to produce the motive fluid.

This subclass is indented under subclass 39.24. Combinations wherein the means to vary the rate of power output regulates the quantity of oxidizer and fuel, separately or as a fuel-oxidizer mixture, comprising the ingredients to produce the motive fluid.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, 319 for speed regulators for internal combustion engines.

Fuel:
This subclass is indented under subclass 39.24. Combinations wherein the means to vary the rate of power output regulates the quantity of fuel comprising an ingredient to produce the motive fluid.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, 350 and 378+ for regulation of fuel to internal combustion engines.

Torque sensor:
This subclass is indented under subclass 39.281. Combinations wherein the means to sense a change in condition of power plant operation is specially designed to sense the turning moment or turning force of a component of the power plant.

This subclass is indented under subclass 39.24. Combinations wherein the means to vary the rate of power output regulates the quantity of oxidizer comprising an ingredient to produce the motive fluid.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.23 for means to vary the oxidizer flow without a condition responsive control thereof.

This subclass is indented under subclass 39.24. Combinations wherein the means to vary the rate of power output regulates the quantity of water or steam comprising an ingredient to produce the motive fluid.

This subclass is indented under subclass 39.01. Devices wherein means are provided for fixing or holding said device relative to some frame of reference.
(1) Note. Means for securing parts or elements of the device to each other are not considered supporting or mounting means for classification in this subclass. A bed plate, per se, is not considered to be a support under this definition.

SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, subclass 16 for power tables or stands comprising portable power units.
244, Aeronautics, subclass 54 for the support in combination with the structure of the airplane.
248, Supports, 637 for machinery supports.
440, Marine Propulsion, 53 for the support in combination with the structure of the boat as such or the propelling means.

This subclass is indented under subclass 39.01. Devices wherein means are provided to permit relative movement between parts to compensate for expansion and contraction.

SEE OR SEARCH CLASS:
285, Pipe Joints or Couplings, subclass 187 for a coupling with means to compensate for expansion and contraction, and subclasses 223+, 261+, 266+, and 302 for pipe joints or couplings which permit relative movement. See the Search Notes thereunder.
403, Joints and Connections, 34 for two members connected by a flexible diaphragm or bellows, subclasses 52+ for articulated members and subclass 220 for two members connected by flexible means.

This subclass is indented under subclass 39.01. Plants including means whereby the plant may be selectively or automatically modified to operate on a different motive fluid or different cycle, or the function of the motor may be changed. Also, plants under subclass 39.01 in combination with features other than combustion products generators and motors, and not provided for in the preceding subclasses.
(1) Note. Combustion products generators and motors include means to supply fuel, steam and/or water, compressors, accumulators, cooling structure, and exhaust treatment devices.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.14 for plants operated by combustion products wherein the operation is changed for starting.
39.64 for plants operated by combustion products wherein the operation is automatically converted in a definite periodic cycle.
424 for plants using a motive fluid other than products of combustion having means for changing from series flow to parallel flow, or vice versa, in a multiple stage motor.
596 and 625+, for plants which are convertible from internal-combustion to fluid pressure motor operation.

SEE OR SEARCH CLASS:
91, Motors: Expansible Chamber Type, subclass 11 for motors of the expansible chamber type connected for series flow of motive fluid, with means whereby the motors may be converted to operate with parallel flow of motive fluid.

This subclass is indented under subclass 39.01. Plants including one or more rotating combustion products generators and a turbine. The combustion products generator or generators may be an integral part of the turbine, or may form a separate member rotatable in the same or opposite direction.

SEE OR SEARCH CLASS:
416, Fluid Reaction Surfaces (i.e., Impellers), 20 for combustion products generators carried by propeller blades, the rotation being effected by the discharge of the products of combustion through reaction nozzles.

This subclass is indented under subclass 39.34. Plants in which the combustion within the combustion products generator or generators proceeds in an uninterrupted or continuous manner.
(1) Note. See (1) Note under subclass 39.01 for definition of "continuous combustion type".

This subclass is indented under subclass 39.01. Plants comprising a turbine and a single combustion products generator, the axis of the combustion products generator being coaxial with the turbine shaft.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.34 for rotating combustion products generator and turbine, in which the generator axis may be coaxial with the turbine shaft.
200 for combinations wherein coaxial combustion products generator and turbine deliver exhaust gases to a jet reaction nozzle.

This subclass is indented under subclass 39.01. Plants in which a turbine is fed with combustion products from a plurality of combustion products generators lying in a ring whose axis is coaxial with the turbine shaft.

SEE OR SEARCH THIS CLASS, SUBCLASS:
35.6 for combinations wherein plural combustion products generators in a ring coaxial with a turbine deliver exhaust gases to a jet reaction nozzle.
39.34 for rotating combustion products generators and turbine.

This subclass is indented under subclass 39.37. Plants in which the combustion products generators operate in a cyclic manner to intermittently produce and discharge combustion products.
(1) Note. See (1) Note under subclass 39.01 for definitions of "intermittent combustion type".

This subclass is indented under subclass 39.38. Plants in which the inlet and/or discharge ports of the combustion products generators are opened and closed by a common rotary valve member.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.38 for plants in which the turbine or compressor rotor is provided with one or more solid portions which cooperate with ports in the combustion products generators to perform valving function.

This subclass is indented under subclass 39.38. Plants in which the inlet and/or discharge valves of the combustion products generators are actuated by a common cam member.

This subclass is indented under subclass 39.01. Plants including a movable pumping means connected with the combustion products generator to withdraw all or a part of the combustion products. This pump may deliver the combustion products at an increased pressure to a receiver or prime mover, or may serve to scavenge the combustion products generator or to draw in a new fuel charge or air.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.56 for jet pumps for mixing steam and combustion products.
39.7 for jet pumps wherein the combustion products from one generator scavenge the combustion products from a cooperating generator or draws a new fuel charge or air into said cooperating generator.

This subclass is indented under subclass 39.01. Plants
having a single turbine rotor with blade structure and flow passages whereby the turbine rotor may be selectively operable in either direction, usually by providing separate forward and reverse blading on the rotor.

SEE OR SEARCH CLASS:
415, Rotary Kinetic Fluid Motors or Pumps, appropriate subclasses for gas operated reversing turbines, per se.

This subclass is indented under subclass 39.01. Plants wherein the turbine rotor, in addition to its usual function as a power producing element, also serves, at the same time, to compress an oxidizer, fuel, or a fuel charge, for use in the power cycle.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.33 for turbines which may be selectively or automatically converted to operate as compressors.

SEE OR SEARCH CLASS:
415, Rotary Kinetic Fluid Motors or Pumps, 175 and 177+ for turbines carrying fan blades for the circulation of a cooling medium.

This subclass is indented under subclass 39.01. Plants including a turbine of the so-called "closed pocket" type. The motive fluid, introduced into these pockets, is trapped therein, and while so trapped is incapable of exerting any useful energy release by expansion, impulse, or reaction. Turbines of this type are considered to be inoperative to produce useful power.
(1) Note. To be classified herein, the patent, in addition to disclosing a closed pocket turbine, should claim the turbine more specifically than merely as a "turbine" or "rotor", or similar broad language.

This subclass is indented under subclass 39.01. Plants including a compressor utilizing interengaging impellers, a liquid or gas under pressure which directly contacts a gas to be compressed, or a rotating helix or screw, to compress the air, fuel, or fuel charge used in the plant.

SEE OR SEARCH CLASS:
415, Rotary Kinetic Fluid Motors or Pumps, appropriate subclasses for rotary pumps and compressors, per se, and see the search note to Class 60, References to Other Classes of the Class 415 Class Definition for a statement of the line.
417, Pumps, subclass 64 for a gas pressure pump using a rotary cellular conveyer; and 65+ for pumps of the type having one fluid pumped by another.
418, Rotary Expansible Chamber Devices, 166 for a rotary expansible chamber device of the moving cylinder type having intermeshing peripheral surfaces and subclasses 191+ for rotary expansible chamber devices of the interengaging rotating member type.

Using special fuel or oxidizer:
This subclass is indented under subclass 39.01. Plants using other oxidizer or fuel than air, oil or gasoline, in which parts of the plant are modified to utilize such other oxidizer or fuel.
(1) Note. See Lines With Other Classes in the Class Definition for the line with Class 110.

SEE OR SEARCH CLASS:
44, Fuel and Related Compositions, 300 for liquid fuels for various uses.
110, Furnaces, see (1) Note above.

Monofuel type:
This subclass is indented under subclass 39.461. Plants using a single component fuel which is decomposed into its constituents to form a high pressure working fluid.

Plural distinct fuels:
This subclass is indented under subclass 39.461. Plants which use two or more different fuels.

Solid, slurry, emulsive or suspensive type fuel:
This subclass is indented under subclass 39.461. Plants which use a fuel that is either: (a) a substance or material having a definite volume and shape, i.e., a solid; (b) a relatively dense mixture of a particulate solid and liquid, i.e., a slurry; (c) a mixture of liquids in which the liquids are indissolvable in each other, i.e., an emulsion; or (d) a mixture of a particulate solid dispersed in a liquid and in which the solid is indissolvable in the liquid, i.e., suspension.

SEE OR SEARCH CLASS:
516, Colloid Systems and Wetting Agents; Subcombinations Thereof; Processes of Making, Stabilizing, Breaking, or Inhibiting, for colloid systems or agents for such systems or making or stabilizing such systems or agents, especially 9 for continuous liquid phase (emulsions, slurries, suspensions), subclasses 98+ for continuous or semicontinuous solid phase (gels, pastes); in each instance, when generically claimed or when there is no hierarchically superior provision in the USPC for the specifically claimed art.

Gaseous fuel at standard temperature and pressure:
Plants under 39.461 which use a fuel that is a gas at standard temperature and pressure.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.12 for plants which include means to generate a gaseous fuel.

This subclass is indented under subclass 39.46. Plants in
which the motive fluids or products of combustion are produced by the combustion of a solid fuel which carries sufficient oxidizer incorporated therein to provide at least the major portion necessary to burn the fuel.

SEE OR SEARCH THIS CLASS, SUBCLASS:
632 for one shot explosion actuated expansible chamber type motors.

SEE OR SEARCH CLASS:
102, Ammunition and Explosives, 530 for pressure gas generating cartridges.
149, Explosive and Thermic Compositions or Charges, appropriate subclasses for thermic or explosive compositions, per se.

This subclass is indented under subclass 39.01. Plants including means to apply fluid pressure against oxidizer, fuel, or water, in a receiver, either directly or through a separating member, to forcibly feed a combustion products generator.
(1) Note. By "separating member" is meant a flexible diaphragm or piston follower which functions to transmit the pressure of a fluid to the oxidizer, fuel or water.

SEE OR SEARCH CLASS:
222, Dispensing, 394 for fluid pressure discharge in dispensing devices.

This subclass is indented under subclass 39.01. Plants in which air is delivered to the combustion products generator through a jet type pump, the motivating fluid for the jet type pump being fuel or steam vaporized by the heat in the system.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.12 for plants in which air is fed into the system by combustible gas generated in a combustible gas generator distinct from and independent of the combustion products
generator.

SEE OR SEARCH CLASS:
239, Fluid Sprinkling, Spraying, and Diffusing, appropriate subclasses, especially 398 for a discharge distributor including means to mix a plurality of fluids, even though the distributor is disclosed as burner.
417, Pumps, subclass 158 for jet pumps in combination with means to generate motive fluid therefor, the motive fluid generator, in many cases, comprising means to vaporize a liquid.

This subclass is indented under subclass 39.01. Plants including means to act upon or re-use the motive fluid after its discharge from the power elements, as, for example, by cooling, compressing, mixing with another fluid, or recirculating it in the power cycle.

SEE OR SEARCH THIS CLASS, SUBCLASS:
272 for exhaust treating devices in combination with internal-combustion engines.
654 672, 681, 683, and 685+, for exhaust treatment of steam driven motors.

Regenerator:
This subclass is indented under subclass 39.5. Plants in which means are provided to transfer heat from the exhausted motive fluid to the air prior to the delivery thereof to the combustion products generator.

SEE OR SEARCH THIS CLASS, SUBCLASS:
96 for air cooling of the exhaust from a steam driven motor.
320 for air cooling of the exhaust gases from an internal-combustion engine.

Rotary heat exchanger:
This subclass is indented under subclass 39.511. Plants including rotatable heat exchange structure.

SEE OR SEARCH CLASS:
165, Heat Exchange, subclass 8 for rotary heat exchangers in general.

This subclass is indented under subclass 39.5. Plants in which some or all of the exhaust gases are returned to the circuit to form a portion of the motive fluid.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39 and 40, for combinations in which a portion of the exhaust is mingled with live motive fluid between the generator and motor, no combustion products fluid being involved.
39.43 in which a portion of the combustion products or exhaust gases is recycled incidental to the dual function of the turbine.
654 672, 681, 683, and 691, for combinations of a motor with means for returning the exhausted motive fluid, without dissipation of the heat content remaining therein, to the place where energy was originally imparted thereto.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, 568.11 for devices to mix a portion of the exhaust gases with the fuel charge.

This subclass is indented under subclass 39.01. Plants including means to add water and/or steam to the motive fluid before its discharge from the prime mover, or to the oxidizer or fuel delivered to the combustion products generator, which fuel and oxidizer are burned to form the motive fluid.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.04 for processes involving the addition of water and/or steam to the fuel or oxidizer, or to the combustion products
prior to the discharge from the motor.
39.3 for plants including means to automatically regulate the water and/or steam.

This subclass is indented under subclass 39.53. Plants in which the steam and/or water is added to the motive fluid within the working space of the turbine or expansible chamber motor.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.17 for multiple expansion motors in which steam and/or water is added to the products of combustion between successive expansion stages.
39.58 for plants in which the steam and/or water is added in the turbine nozzle.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, subclass 25 for internal-combustion engines with means to supply water or steam to the working cylinder to mix with the products of combustion therein.

This subclass is indented under subclass 39.53. Plants in which the steam and/or the water is added to the products of combustion within the combustion chamber of the combustion products generator.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.49 for injectors utilizing steam to feed air into a combustion products generator.

SEE OR SEARCH CLASS:
110, Furnaces, 199, 296 and 297+ for feeding steam and/or water to furnaces.
239, Fluid Sprinkling, Spraying, and Diffusing, appropriate subclasses for a fluid discharge distributor system even though disclosed as a burner, especially 128 for means to heat the fluid or the system, and subclasses 398+ for means
to mix a plurality of fluids prior to, at or subsequent to discharge.
431, Combustion, appropriate subclasses for combustion apparatus not disclosed solely for utilization in a prime mover in which water or water vapor is fed to interact with fuel and oxidizer.

This subclass is indented under subclass 39.53. Plants in which the union of steam and/or water with products of combustion takes place in a zone above a standing body of water, the water being heated by the products of combustion.

This subclass is indented under subclass 39.56. Plants in which the products of combustion are discharged below the surface of the water in order that they may bubble through the water to the mixing zone.

SEE OR SEARCH CLASS:
126, Stoves and Furnaces, subclass 360.2 for a submerged fluid fuel burner other than a top-accessible liquid heating vessel having direct contact of the liquid by exhaust.

This subclass is indented under subclass 39.53. Plants in which the steam and/or water is united with the products of combustion in a mixing nozzle between the combustion products generator and motor or place of utilization, or is united in a turbine nozzle.

This subclass is indented under subclass 39.53. Plants in which the combustion products and steam and/or water are united in a receiver distinct from the boiler or combustion
chamber of the combustion products generator.
(1) Note. The "boiler", as used above, refers to a receiver for a standing body of water in which the steam is generated, and having a space above the water for the collection of the steam.

This subclass is indented under subclass 39.01. Plants including a prime mover comprising a motor of the expansible chamber type, the motor being in communication with an external-combustion products generator by means of a periodically opened transfer valve or equivalent means, to admit products of combustion into the working space on the power stroke of the motor piston. In an intermittently fired combustion products generator, ignition must be initiated prior to the opening of the transfer valve or equivalent means.

SEE OR SEARCH THIS CLASS, SUBCLASS:
632 for one shot explosion actuated expansible chamber type motors.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, appropriate subclasses, for prime movers of the expansible chamber type having a combustion chamber separated from the working space by a periodically opened transfer valve or equivalent means, the transfer valve or equivalent means being open at the instant of ignition. Note 253.

This subclass is indented under subclass 39.6. Plants in which a power cylinder receives combustion products alternately from two or more consecutively fired intermittent type combustion products generators.

This subclass is indented under subclass 39.6. Plants in which the combustion within the combustion products generator
proceeds in an uninterrupted or continuous manner.
(1) Note. See (1) Note under subclass 39.01 as to definition of "continuous combustion type".

This subclass is indented under subclass 39.01. Plants in which an intermittently actuated motive fluid generator discharges combustion products, and alternately therewith, in a regular cyclic manner, also discharges distinct volumes of a different motive fluid, such as heated air or steam.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.18 for internal-combustion engines having separate fluid pressure expansion strokes.
39.33 for plants in which the discharge of combustion products and a different motive fluid is selective.

This subclass is indented under subclass 722. Devices, comprising a generator of combustion products and a turbine receiving and driven by such products.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.34 for rotating combustion products generator and turbine.
39.36 for coaxial combustion products generator and turbine.
39.37 for plural combustion products generators arranged in a ring coaxial with turbine.
39.42 for combustion products generator with reversible turbine.
39.43 for combustion products generator with dual function turbine.
39.44 for combustion products generator with closed pocket turbine.
39.73 for combustion products generator located in turbine nozzle.

SEE OR SEARCH CLASS:
415, Rotary Kinetic Fluid Motors or Pumps, appropriate subclasses, for gas operated turbines, per se.

This subclass is indented under subclass 722. Combustion devices, having valves or equivalent means operating in a cyclic manner to intermittently produce and discharge combustion products.
(1) Note. See (1) Note under subclass 39.01 for definition of "intermittent combustion type."

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.38 for plants including a plurality of intermittent combustion type generators arranged in a ring coaxial with a turbine shaft.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, subclass 657 for combustion chambers for internal-combustion engines.

This subclass is indented under subclass 39.76. Combustion devices in which a resonating or pulsating condition within the combustion products generator, due to the cyclic combustion of a fuel charge, is utilized to effect the exhaust of the products of combustion and the suction and compression of air or a fuel charge.

This subclass is indented under subclass 39.76. Combustion devices in which rotating, revolving, reciprocating, or oscillating combustion device cooperates with ports in a stationary or relatively movable valve member to control the cyclic events of the intermittent combustion cycle.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.34 for rotating combustion products generator and turbine.

This subclass is indented under subclass 39.76. Combustion devices in which the combustion air, fuel charge, fuel feeding or exhaust valve is cyclically actuated by a fluid under pressure the application of such fluid under pressure being periodically controlled by a valve or similar means.

This subclass is indented under subclass 39.76. Combustion devices in which the combustion air or fuel charge inlet valve, or the combustion products outlet valve, is cyclically actuated by the pressure at which the air, fuel charge or combustion products are delivered to or discharged from the combustion products generator.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.7 for combustion products generators in which the valves in one generator are operated by pressure fluctuations in another generator.
39.77 for pressure actuated valves in resonating combustion products generators.

This subclass is indented under subclass 39.76. Combustion devices in which the fuel or fuel charge inlet valve is provided with means to cyclically feed a measured supply of fuel or fuel charge into the combustion device when actuated.

With ignition device:
This subclass is indented under subclass 39.69. Combustion
devices in combination with an ignition device in the form of means to provide a source of heat to initiate combustion of a fuel charge or to maintain combustion within a combustion products generator.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.06 for processes of ignition. 39.14, for igniters combined with starting devices.

SEE OR SEARCH CLASS:
123, Internal-Combustion Engines, 143 for igniters for internal-combustion engines.
431, Combustion, appropriate subclass for a residual fuel burner having an ignition means.

Catalytic type:
Combustion devices under 39.821 wherein the ignition device comprises structure in the form of a substance that increases the rate of chemical reaction of reactants brought into physical contact with the structure.

Pyrotechnic squib or charge type:
This subclass is indented under subclass 39.821. Combustion devices wherein the ignition device comprises structure composed of explosive-type materials but which has been modified or designed to burn rather than to explode.
(1) Note. The devices of this subclass are very similar to common fireworks and in particular firecrackers which have been ruptured or otherwise modified to cause the device to burn rather than to explode as in normal operation.

Hypergolic type:
This subclass is indented under subclass 39.821. Combustion devices wherein the ignition device comprises structure designed to bring into contact fuel components which ignite spontaneously upon contact with each other.

Single shot liquid type:
This subclass is indented under subclass 39.821. Combustion devices wherein the ignition device comprises structure specially designed to deliver a discrete quantity of liquid fuel in to a combustion chamber during a specified time period.

Pilot or torch type:
This subclass is indented under subclass 39.821. Combustion devices wherein the ignition device comprises a small jet designed to continuously supply gaseous fuel which either remains constantly burning or is otherwise ignited when desired.

Spark type:
This subclass is indented under subclass 39.821. Combustion devices wherein the ignition device comprises structure designed to produce an electrical discharge through normally insulative material, e.g., through air or similar atmospheric substances.

Incandescent type:
This subclass is indented under subclass 39.821. Combustion devices wherein the ignition device comprises structure which either, (a) is capable of being made incandescent prior to and to produce initial combustion operation of the combustion device, or (b) is capable of being raised to and maintained for a sustained period of time in an incandescent state wherein the ignition device is raised to this state during an uninterrupted period of combustion of the combustion device.
(1) Note. A typical example of the type of ignition device provided for in (a) above would be an electrical filament through which an electrical current is passed causing the filament to become heated and incandescent. Similarly, a typical example of the type of ignition device provided for in (b) above would be a ceramic structure which upon being heated by combustion heat retains this heat for a very long
time and therefore can be used to re-ignite a combustion device in which combustion has ceased.

Cooling of auxiliary components:
This subclass is indented under subclass 39.01. Plants having means to cool engine components other than those specifically provided for in preceding subclasses.
(1) Note. Patents classified herein include cooling of the engine casing, auxiliaries (e.g., starter motor, fuel pump, generator), and bearings not specifically disclosed or claimed as integral components of the compressor or turbine element.
(2) Note. An engine shaft is considered an element of either the compressor or motor, and coiling therefor is classified under the appropriate compressor or motor classification. However, cooling of a shaft bearing would be included herein.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.5 for cooling of the exhaust structure.
39.75 for cooling of the turbine and associated shaft.
39.82 for cooling of the igniter.
726 for cooling of the oxidizer compressor and associated shaft.
740 for cooling of the fuel injector.
752 for cooling of the combustor liner.

REACTION MOTOR (E.G., MOTIVE FLUID GENERATOR AND REACTION NOZZLE, ETC.):
This subclass is indented under the class definition. Apparatus or process for producing a useful thrust in one direction by the expulsion of a motive fluid therefrom in a opposite direction comprising a means for or step of producing said motive fluid and a means for or step of ejecting said motive fluid.
(1) Note. See (1) Note in subclass 205 for a glossary of terms used in the titles and definitions of subclass 200.1 and indented subclasses.
(2) Note. This definition includes electronic propulsion devices commonly known as "ion motors" wherein a thrust is obtained in one direction by the ejection in the opposite direction of ions accelerated electronically or by other means and expelled into the ambient.
(3) Note. The "means for or step of producing said motive fluid" in the definition may be, for example, any means for imparting energy to the motive fluid such as a heating means, an ion accelerating means, a combustion chamber, a source of such motive fluid such as a tank or merely a pump, and the "means for ejecting said motive fluid" may be merely a pipe, though it is usually a nozzle.
(4) Note. Apparatus under this definition is usually used to cause motion of a vehicle to which it is attached but it may be used to cause merely a thrust without producing movement. Many apparatuses inherently cause a thrust while accomplishing some other function and comprise a pressure fluid producing means and a fluid ejecting means. Such apparatuses are not classified under this definition but in appropriate other classes based on the disclosed function, e.g., Class 239, Fluid Sprinkling, Spraying, and Diffusing, would be the locus for a system comprising a pump connected to a nozzle used primarily to spray water and not to produce a thrust. On the other hand, a device comprising merely a pump and an output pipe which would normally be classified in Class 417, Pumps, or Class 418, Rotary Expansible Chamber Devices, is classifiable under this definition if the disclosure is limited to the use of a device as a reaction motor, e.g., to drive a boat. An exception to the above described use classification is made in the case of those power plants classifiable in Class 60, subclasses 39.01. Even if the sole disclosure of such a power plant is to produce a thrust it is not classifiable under this definition unless the nozzle is specifically described in the claim.
(5) Note. This class provides for the combination of a reaction propulsion device and a vehicular device wherein no more structure of the vehicular device is claimed than is necessary to mount the propulsion device. Any additional significantly claimed vehicle structure will require classification in the proper vehicle class.
(A) In the following instances, the structure of the vehicle was considered not to be significantly claimed: (a) The vehicle is included in the combination by name only (e.g., the vehicle is not modified, other than that required to accommodate the reaction motor, or identified as to any designation of the general class to which the vehicle belongs. (b) The location of the reaction motor or any part thereof, on the vehicle is defined merely by stating a relationship between the vehicle, as a unit, and the reaction motor (e.g., the motor is located at the front, rear, right, left, top, bottom, within or outside the vehicle, bow, stern, at the water line, center of gravity, or center line.
(B) In the following instances, the structure of the vehicle was considered to be significantly claimed: (a) The location of the reaction motor or motors or any part or parts thereof on the vehicle is defined by stating a plurality of relationships, anyone of which alone would be considered insignificant (e.g., one reaction motor on each side, or a reaction motor mounted within the vehicle rearwardly of the center of gravity). (b) The location of the reaction motor or any part thereof, on the vehicle is defined by stating a relationship between a specific part of the vehicle and the motor (e.g., motor located on the wing, keel or rudder of a ship). (c) The structure of the vehicle is modified to an extent greater than that required to position or support the reaction motor or its parts (e.g., claiming the shape of the hull of a ship). (d) The vehicle is provided with means for guiding, deflecting, or reacting with the propulsion fluid subsequent to its discharge from the nozzle of the reaction motor (e.g., the motor is located in an open channel or adjacent a rudder of a ship).
(6) Note. A component part of an apparatus under this definition necessary for its operation often is a motor, which, for example, may drive a compressor furnishing air to a combustion products generator which supplies motive fluid to a means (nozzle) for ejecting the fluid. Such motor may have a shaft output for an external load and the load on the shaft, e.g., a propeller, may even be nominally claimed and the apparatus will still be classified under this definition. However, if an apparatus under this definition has combined therewith an added motor used only for an external load, the whole apparatus is considered a combined reaction motor and other type motor for classification in subclasses 200.1+.
(7) Note. Under this definition the motive fluid generating means, as claimed, may itself be a motor having a transmission means and a nominal load.
(8) Note. Dual Use Disclosure Patents which claim an apparatus having means to pressurize a fluent and a means through which the pressurized fluent may be ejected and which disclose a dual use for said apparatus, one of the uses being to produce a thrust, (e.g., pump a fluid and produce a thrust) are classified as follows: If the apparatus, in addition to the thrust producing use, is disclosed as used as an electrical energy discharge device, classification is in Class 60. Otherwise, patents are placed in Class 60 only if the sole disclosed use of the apparatus claimed is to produce a thrust or wherein combustion products are generated for use as motive power. Classification of apparatus, for example, which may be used to produce a thrust and also used as a pump is in Classes 415, 416, 417, or 418, or if also used to produce hot gas by a means which burns a fuel in Class 431, or if also used to distribute a hot gas is in Class 239.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.01 for power plants employing combustion products as the motive fluid and disclosed as being used with a reaction nozzle means to produce a thrust but not specifically claiming the nozzle means.

SEE OR SEARCH CLASS:
44, Fuel and Related Compositions, appropriate subclasses for a solid or liquid fuel composition including petroleum fuels, such as gasoline, admixed with other materials. The lines between Class 44 and this class are: (1) A patent containing a fuel composition claim and a claim to broadly creating propulsion by burning the fuel is classified in Class 44 and cross-referenced to this class. (2) A patent containing only process claims even if they merely recite burning a definite fuel to broadly produce thrust is classified in this class.
73, Measuring and Testing, 116 for motor and engine testing and subclass 147 for wind tunnel; aerodynamic wing and propeller study.
86, Ammunition and Explosive-Charge Making, subclass 1 and 20 for apparatuses and processes for filling or loading a casing with propellant.
102, Ammunition and Explosives, for devices disclosed as explodable projectiles having an explosive or explosive carrying compartment and having a propelling charge. See in particular 347 for skyrockets having explosive charges to give visual effects, flight control means, ground support illuminating means, etc., subclasses 374+ for projectiles having jet reaction propulsion means, subclasses 334 and 366+ for shells adapted to emit an incendiary or smoky substance during flight, subclasses 200+ for fuses, primers and igniting devices, subclass 458 for tracer shells and subclasses 283+ for the shape or structure of powder grains, sticks or bars of an explosive substance arranged for the purpose of modifying the rate or manner of burning or exploding.
105, Railway Rolling Stock, subclass 26 for jet propelled rail vehicles.
110, Furnaces, for a combustion chamber structure of general utility or a method of operating the same with means to burn a solid fuel or solid fuel with auxiliary gas or liquid fuel and with or without means to feed said fuel to the burner means. These furnaces may also convert from a solid fuel burner to a gas or liquid fuel burner.
114, Ships, 20 for self-propelled torpedoes, and subclasses 150+ for ships having steering means involving fluid pressure and jet means.
137, Fluid Handling, for fluid distribution systems for control of a motor means. Control of a reaction motor disclosed as the type classified in Class 60 would be
classified in Class 60 if the reaction motor is claimed specifically or broadly. To claim, for example, merely a housing or chamber for a reaction motor would not preclude classification from Class 137. However, patents claiming specific motor structure and fuel control means for said motor, structural means interconnecting a motor and fuel control means, or a fuel control means broadly or specifically responsive to a motor condition are classified in Class 60. See 15.1 for jet engine intake means, per se, having means to handle fluid therein.
138, Pipes and Tubular Conduits, for tubular members of definite or indefinite length and especially 40 for pipes having variable or nonvariable means (e.g., reaction motor diffusers) to restrict the flow of fluid therethrough, subclasses 89+ for a pipe with a closure and subclasses 111+ for plural ducting in a single pipe.
149, Explosive and Thermic Compositions or Charges, appropriate subclasses for propellant compositions containing a fuel and an oxidizer. The lines between Class 149 and this class are: (1) A patent containing a propellant composition claim and a claim broadly creating propulsion by burning the propellant is classified in Class 149 and cross-referenced to this class. (2) A patent containing only process claims even if they merely recite burning a definite propellant to broadly produce thrust are classified in this class.
165, Heat Exchange, 51 for heat exchangers associated with an engine.
175, Boring or Penetrating the Earth, 11 and in particular subclass 14 for devices for boring earth in situ employing a combustion product generator and a nozzle means to accelerate said products. Also see Note V of the class definition of Class 175 particularly as it refers to Class 125, Stone Working.
180, Motor Vehicles, subclass 7 for a motor vehicle having a special device (e.g., a reaction motor for propelling it; and subclasses 116+ for a motor vehicle having means for maintaining a working fluid mass between a surface of the vehicle and a reaction supporting surface.
220, Receptacles, 581 for a high-pressure-gas tank, subclass 13 for receptacles having water jackets and subclasses 265+ for containers having frangible type closures.
222, Dispensing, 251 for means to dispense material with discharge assistant means (e.g., impeller, pump, etc.)
227, Elongated-Member-Driving Apparatus, for means to cause engagement between an elongated member and another member.
239, Fluid Sprinkling, Spraying, and Diffusing, appropriate subclass for a terminal flow modifying means, e.g., nozzle for a fluid, especially 127.1 and 265.11+ for a reaction
motor discharge nozzle, per se, or such nozzle claimed in combination with a mere combustion chamber or other means imparting energy to a fluid in the absence of specific details of the energy imparting means or a specific relationship between the means and the terminal means. Devices claiming specific means by which combustion products are produced in a combustion chamber to be used solely in a motor or thrust device (e.g., fuel injector, solid fuel and, etc.), or specific means by which a pressure is maintained on a stored fluid (e.g., contractible chamber) together with a nozzle for the production of a thrust are, however, classified in Class 60. Condition responsive means controlling flow through a nozzle is classified in Class 239 regardless of the parameter sensed.
244, Aeronautics, for machines adapted to be sustained by air or propelled through air, and devices such as air foils which react with the atmosphere for controlling or sustaining flight. See in particular subclass 1 for space craft, subclasses 3.1+ for an aerial missile (including a projectile) with means to stabilize or affect the trajectory or course of the missile, subclasses 7, 12.1+, 14, 15, and 23 for aircraft using jet reaction devices principally to assist in vertical lift, subclass 52 for aircraft having jet reaction devices for steering and propulsion, subclasses 73 and 74 for aircraft having jet reaction propulsion means, subclass 78 for aircraft controlled by jet reaction devices, and subclass 113 for aircraft provided with jet reaction means to retard motion.
248, Supports, 637 for machinery supports.
261, Gas and Liquid Contact Apparatus, appropriate subclasses, for the oxidizer and fuel mixing subcombinations of reaction motors.
299, Mining or In Situ Disintegration of Hard Material, subclass 14 for processes involving the use of a fluid unconfined jet stream to comminute hard material (e.g., rock) in situ.
415, Rotary Kinetic Fluid Motors or Pumps, 80 for a motor runner having a reaction type jet discharge for causing rotation about an axis.
416, Fluid Reaction Surfaces (i.e., Impellers), for vehicular propulsion devices having significantly claimed propeller structure and broadly recited reaction nozzle means distinct from the propeller for the production of a reaction thrust. On the other hand, the combination of a nominally claimed propeller and a reaction motor is classifiable under this definition. When the propeller and a reaction motor are significantly claimed and the reaction motor produces a thrust which does not drive the propeller, the device is considered a combined type power plant for Class 60, 6 However, where the propeller and jet reaction device form a unitary structure or are otherwise structurally related so
that substantially all of the output of the reaction device directly or indirectly rotates the propeller, classification is in Class 416, see in particular subclasses 20+.
417, Pumps, for pump details, and particularly 73 for pumps of the type in which fluid is pumped by the combustion of a motivating fluid in contact with the pumped fluid, and subclasses 321+ for motor driven pumps, including those in which the pump output is disclosed but not claimed as being delivered to the drive motor (e.g., supercharger) and those wherein the compressor output is claimed as being delivered to the motor and is tapped for use externally of the motor-pump combination, and also pumps having an output which is disclosed as being discharged for a purpose other than that of producing thrust.
418, Rotary Expansible Chamber Devices, for rotary expansible chamber devices, per se.
431, Combustion, for combustion products generators not disclosed for any particular use or disclosed for use other than for external power purposes. A claimed means controlling a Combustion products generator which is responsive to a combustion products actuated motor condition such as speed, thrust, acceleration, etc., is considered to be tantamount to claiming the motor and causes classification in Class 60 rather than in Class 431. See also (8) Note under this subclass concerning dual use disclosures.
440, Marine Propulsion, 38 for a boat or ship propelled or steered by a reaction motor.

This subclass is indented under subclass 200.1. Apparatus or process arranged so as to turn about an axis or having any kind of cyclic movement while producing a coaxial thrust component when in operation.
(1) Note. The motors included in this subclass are usually intended to turn or spin continuously about an axis at constant or variable rates in the nature of that necessary to obtain stabilization in flight or for other reasons. Motors having thrust direction modification means which momentarily causes the motor to rotate or turn about an axis, but which is not intended to impart continuous rotation is found below, for example, in subclasses 228+.
(2) Note: Motors in this subclass may be provided with motive fluid ejecting means to produce rotation thereof. However, motors having means such as an air foil which causes the motor to rotate solely as a result of reaction with ambient air are classified elsewhere, as for example in Class
244, Aeronautics, subclass 3.23. See also Class 102, subclass 350 for pyrotechnic rockets having means to cause rotation of the rocket by gas discharge.

SEE OR SEARCH THIS CLASS, SUBCLASS:
39.01 especially subclass 39.34 for a power plant in which the motor rotates about an axis without producing an axial thrust.

SEE OR SEARCH CLASS:
415, Rotary Kinetic Fluid Motors or Pumps, 80 for a motor runner having a reaction type jet discharge for causing rotation about an axis.
416, Fluid Reaction Surfaces (i.e., Impellers), 20 for an impeller driven by a fluid reaction jet on the working member.

This subclass is indented under subclass 200.1. Apparatus or process in which charged particles are ejected by application of an electrical force, e.g., an electromagnetic force.

SEE OR SEARCH CLASS:
219, Electric Heating, 121.36 for means for heating a workpiece by directing to said workpiece ionized particles which had been created by an electrical arc drawn between two electrodes.
250, Radiant Energy, 281 for mass spectroscopy methods and apparatus which ionize the particles through an electrostatic or magnetic field for separation of certain of the particles, subclass 396 for electron or ion beam deflection of focussing methods or apparatus and subclasses 423+ for ion generation methods and apparatus.
310, Electrical Generator or Motor Structure, subclass 11, for dynamo-electric machinery employing a plasma to exert a mechanical force.
313, Electric Lamp and Discharge Devices, subclass 62 for electrical space discharge devices provided with magnetic means for confining the path of the particles discharged and accelerating said particles; subclasses 359.1+ for discharge devices provided with means for generating and accelerating positive ions; subclasses 153+ particularly subclass 161, for space discharge devices having a magnetic field designed to influence a space discharge; subclasses 231.01+ for discharge devices having fluent material supply or flow directing
means.
315, Electric Lamp and Discharge Devices: Systems, 111.01 for a discharge device having means to supply a fluent material to a discharge area between discharge electrodes.
322, Electricity: Single Generator Systems, subclass 48 for plasma generating means.
324, Electricity: Measuring and Testing, 300 for means by which a substance may be ionized and the ionized particles moved through a magnetic field for observation so that the substance may be identified.
376, Induced Nuclear Reactions: Processes, Systems, and Elements, 100 for processes and devices that utilize a gaseous or light element fuel material, the particles of which are electrically charged or excited to the point where they become highly ionized and the forces of repulsion of like nuclei are overcome to the end that thermonuclear fusion of such like nuclei is obtained or sought to be obtained.
417, Pumps, 48 for electrical (e.g., ionic) or getter type pumps.

Electric, nuclear, or radiated energy fluid heating means:
This subclass is indented under subclass 200. Apparatus or process in which the motive fluid is heated directly or indirectly, through a heat transfer medium, by electrical energy, by radioactive decay, or by radiated energy (e.g., solar radiated energy, radio wave energy, etc.).

SEE OR SEARCH CLASS:
219, Electric Heating, 628 and 772 for transferring heat to a fluent material by an inductively and capacitive dielectric heated member.
376, Induced Nuclear Reactions: Processes, Systems, and Elements, 317 for propulsion systems or processes powered directly or indirectly by induced nuclear reactions.

This subclass is indented under subclass 200.1. Processes.
(1) Note. Subject matter under this definition includes methods for maintaining reaction motors in operative
condition.
(2) Note. Methods of making reaction motors are classifiable in appropriate process classes. A patent having a claim to a reaction motor as an apparatus and also a claim to a method of making said motor is classifiable as an original in the appropriate subclass for the apparatus and cross-referenced to the appropriate process class.

SEE OR SEARCH CLASS:
208, Mineral Oils: Processes and Products, 15 for a petroleum fuel, such as gasoline, subclasses 22+ for an asphalt tar, pitch or resin mineral oil composition and subclass 39 for making, treating and recovery of asphalt, tar, pitch or resin.
502, Catalyst, Solid Sorbent, or Support Therefor: Product or Process of Making, appropriate subclass for a catalyst composition or a process of making or regenerating such composition.
(1) Note. Terms or phases used in titles or definitions are set forth at the end of this subclass with the meaning each is to have in this group of subclasses (205+).

This subclass is indented under subclass 204. Processes directed to producing thrust in a reaction motor by ejecting the products of chemical reaction of propellant material.
(1) Note. This and indented subclasses take (1) processes involving injecting propellant material into the reaction zone in one or more streams, reacting the material and expelling the reaction products to produce thrust; (2) processes involving reacting propellant material in the reaction chamber and expelling the reaction products to produce thrust.
(2) Note. The lines between this and indented subclasses and Class 44, Fuel and Related Compositions, Class 149, Explosive and Thermic Compositions or Charges, Class 208, Mineral Oils: Processes and Products, Class 260, Chemistry of Carbon Compounds, and Class 423, Chemistry of Inorganic Compounds and Class 585, Chemistry of Hydrocarbon Compounds, are as follows: (1) patent containing a propellant material claim and a claim to broadly creating propulsion by merely broadly reacting the propellant material are classified in the appropriate material class and cross-referenced to this and indented subclasses. (2) A patent containing only process claims which merely recite reacting a definite propellant material to broadly produce thrust are classified in this and
indented subclasses.
(3) Note. The processes of this and indented subclass include operating the reaction motor in such media as water, air and vacuum.

SEE OR SEARCH CLASS:
44, Fuel and Related Compositions, appropriate subclasses for a solid or liquid fuel composition. The lines between Class 44 and this class are: (1) A patent, containing a fuel composition claim and a claim to broadly creating propulsion by burning the fuel is classified in Class 44 and cross-referenced to this class. (2) A patent containing only process claims even if they merely recite burning a definite fuel to broadly produce thrust are classified in this class.
102, Ammunition and Explosives, 530 for sky-rockets, subclasses 374+ for a projectile having a charge which discharges to propel the projectile after leaving the gun, subclasses 334 and 366+ for shells adapted to emit an incendiary or smoky substance during flight, subclass 458 for tracer shells and subclasses 283+ for inventions in the shape or structure of powder grains, sticks or bars of an explosive substance usually arranged for the purpose of modifying the rate or manner of burning or exploding.
114, Ships, 20.1 for fish or automobile torpedoes, the power or propulsion being self-contained.
149, Explosive and Thermic Compositions or Charges, appropriate subclasses for propellant compositions containing a fuel and an oxidizer. The lines between Class 149 and this class are: in particular, see subclass 109.2 for a collection of gas generation and propulsion methods using compositions not provided for elsewhere in the class, subclass 109.4 for a collection of monopropellant compounds, subclass 119 for a collection of oxidizer compounds and subclasses 120+ for a collection of high energy fuel compounds. (1) A patent containing a propellant composition claim and a claim to broadly creating propulsion by burning the propellant is classified in Class 149 and cross-referenced to this class. (2) A patent containing only process claims even if they merely recite burning a definite propellant to broadly produce thrust are classified in this class.
208, Mineral Oils: Processes and Products, 15 for a petroleum fuel, such as gasoline, subclasses 22+ for an asphalt tar, pitch or resin mineral oil composition and subclass 39 for making, treating and recovery of asphalt, tar, pitch or resin.
252, Compositions, 186 for oxidizing compositions.
440, Marine Propulsion, subclass 45 for devices causing explosive jets of the nature of those used in air and gas
engines used for propelling a vessel.
502, Catalyst, Solid Sorbent, or Support Therefor: Product or Process of Making, appropriate subclass for a catalyst composition or a process of making or regenerating it.
585, Chemistry of Hydrocarbon Compounds, for certain fuel compositions containing only hydro-carbons and processes for making them.
BIPROPELLANT
A reaction motor propellant consisting of two separate substances (usually liquid) fed into the reaction zone separately. One of the substances is a fuel (e.g., hydrazine); while the other is an oxidizer (e.g., fluorine).
CHEMICAL REACTION
The transformation of the molecules of one or more substances into other kinds of molecules.
FUEL
A single substance or a mixture of substances which react with another substance (called the oxidizer) to form at least one new substance in which at least a portion of the fuel forms at least a portion of the more positive (electron donor) portion of the new substance. e.g.
H[subscrpt]2[end subscrpt] + Cl[subscrpt]2[end subscrpt] ! 2HCl
Hydrogen is considered the fuel.
CH[subscrpt]4[end subscrpt] 2O[subscrpt]2[end subscrpt] ! CO[subscrpt]2 [end subscrpt] + 2H[subscrpt]2[end subscrpt]O
Methane is the fuel and oxygen in the
oxidizer.
BE + F[subscrpt]2[end subscrpt] ! BeF2
Beryllium is the fuel and fluorine in the oxidizer.
HYPERGOLE
A substance (fuel or oxidizer) which ignites spontaneously on contact with the other member of a hypergolic mixture. For example: aniline is hypergolic with nitric acid.
INJECTING
Forcing into the reaction zone one or more streams of material which enter into the action which produces thrust. Extruding a solid or semi-solid into the reaction zone,
spraying a stream of finely divided particles into the reaction zone and jetting a liquid or gas into the reaction zone are illustrative but nonlimiting examples of the scope of the term.
METAL
The term includes a free metallic element (e.g., lithium), an alloy of two or more metals (e.g., 25% Na 75% K), and intermetallic compound (e.g., A1Ni) or a mere mixture of particles of two or more metals.
MONOPROPELLANT
A material which contains within itself all of the components which enter into the chemical change which occurs in producing thrust in a chemical reaction motor. A monopropellant may be a pure compound, such as hydrazine, or a mixture of two or more substances which react under the conditions of the reaction chamber.
MOTIVE FLUID
Used in this definition this term means a stream of moving particles, either gaseous or liquid, as it exists in the area in the motor where it is accelerated, pressurized or otherwise caused to become unstable up to and including the point where it exits the end of the ejecting means, e.g., nozzle, through which it is ejected into the ambient to cause thrust.
OXIDIZER
A substance (element or compound) which reacts with another substance to produce at least one new substance in which at least a portion of the oxidizer furnishes at least part of the more negative (electron acceptor) portion of the new substances. e.g.
BH[subscrpt]3[end subscrpt] + NH[subscrpt]3[end subscrpt] ! BN + 3H[subscrpt]2[end subscrpt]
ammonia is considered the oxidizer
2LiH + F[subscrpt]2[end subscrpt] ! 2LiF + 2HF
fluorine is considered the oxidizer
CH[subscrpt]4[end subscrpt] + 2O[subscrpt]2[end subscrpt] ! CO[subscrpt]2[end subscrpt] + 2H[subscrpt]2[end subscrpt]O
oxygen is the oxidizer
PROPELLANT
The generic term for any or all of the components of the
supply of materials which may be converted (by expansion, combustion or other means) into motive fluid.
REACTION ZONE
The space in which the propellant material undergoes chemical change to produce new substances and heat which heat raises the temperature of the new substances. The ejection of these heated substances from the reaction motor produces thrust or propulsive force.

This subclass is indented under subclass 205. Process directed to utilizing indirect heat exchange within the system.
(1) Note. To come within the purview of this subclass the patent must specifically claim transferring heat within the system from one fluid to another through a solid material, such as using the incoming fuel to cool the discharge nozzle. The latter is being heated by the products of chemical reaction.

SEE OR SEARCH CLASS:
252, Compositions, 71 for a composition designed for use in heat exchange.

This subclass is indented under subclass 205. Process directed to utilizing a plurality of chemical reaction zones in the system.
(1) Note. Such diverse processes as utilizing a main reaction zone and an afterburner zone and utilizing a plurality of reaction zone in parallel within the same system are within the purview of this subclass.
(2) Note. A process for hydrogenating the fuel and then oxidizing the is within the purview of this subclass.

This subclass is indented under subclass 205. Process directed to injecting atmospheric air into the reaction zone of the reaction motor.
(1) Note. This and indented subclasses are limited to operating air breathing reaction motors.

SEE OR SEARCH THIS CLASS, SUBCLASS:
211 for a process in which liquid oxygen or liquid ozone is injected into the reaction zone as an oxidizer component and subclass 220 for a process in which a modifying fluid is injected into a reaction zone containing solid propellant material.

SEE OR SEARCH CLASS:
44, Fuel and Related Compositions, 300 for a liquid fuel mixture which may be used in air breathing reaction motors.
208, Mineral Oils: Processes and Products, 15 for liquid hydrocarbon mixtures such as: gasoline or kerosene.

This subclass is indented under subclass 208. Process directed to using an additive material other than air and fuel.
(1) Note. To be classed as an additive the material must be used in a minor amount with respect to the fuel or the air.
(2) Note. Such substances as: (1) a catalyst, (2) a substance hypergolic with air or the fuel, (3) a substance which forms with the fuel and air a multicomponent hypergolic mixture are within the scope of this and indented subclasses.

SEE OR SEARCH THIS CLASS, SUBCLASS:
212 for utilizing an igniter aid with separately injected fuel stream and oxidizer stream.

This subclass is indented under subclass 209. Process directed to injecting the additive material into the reaction zone as a separate stream.

SEE OR SEARCH THIS CLASS, SUBCLASS:
213 for a process of injecting an igniter aid into the reaction zone in a separate stream.

This subclass is indented under subclass 205. Process directed to injecting into the reaction zone separate streams of fuel and oxidizer.
(1) Note. The injection of separate streams of at least two different substances which react to produce products which are useful to generate thrust is considered injecting separate streams of fuel and oxidizer. The two substances may ignite on contact (hypergolic reaction) or they may be caused to react by various means, such as; a catalyst, an electrical discharge, heat, a substance which is hypergolic with either reactant or the reactant mixture.
(2) Note.