Class Definition for Class 60

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CLASS 60,	POWER PLANTS
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SECTION I - CLASS DEFINITION

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 an element or machine driven by the motor is not generally considered sufficient to exclude the patent from the class.

SECTION II - 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, Hazardous or Toxic Waste Destruction or Containment, subclasses 300-415 and 249-260 for the processes of chemical 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.

SECTION III - 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 subclasses 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, subclasses 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, subclasses 313 through 320for the destruction of hazardous or toxic waste by combustion in a power plant. Class 60 takes the use of hazardous or toxic waste as a useful fuel for power production.

SUBCLASSES

39.01

COMBUSTION PRODUCTS USED AS MOTIVE FLUID:

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.

39.08

With lubricators:

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.

39.091

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:

39.13,	for plants wherein the operation of the generator is stopped and started in response to pressure changes in an accumulator receiving products of combustion.
773,	for a process where combustion products are used as motive fluid having power output control.
793	through 39.3, for a process where combustion products are used as motive fluid combined with regulation of power output feature.

SEE OR SEARCH CLASS:

123,	Internal-Combustion Engines, subclass 198 for safety devices designed for use with internal-combustion engines.

39.092

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.

39.093	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.

39.094	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.

[List of Patents for class 60 subclass 39.1]

39.1

Excess pressure relief:

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, subclasses 455+ for valves which respond to changes in line condition.
220,	Receptacles, subclasses 89.1 through 89.4for frangible or fusible diaphragms which burst or melt to relieve excess pressure.

39.11

Flame screen:

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, subclasses 88.1+ for flame guards for receptacles.
222,	Dispensing, subclass 189.01 for flame guards for dispensers.

39.12

With combustible gas generator:

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.

39.13

Automatic starting and stopping of combustion products 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:

39.24+,	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.
786	through 790, for a power plant where combustion products are used as motive fluid combined with a starting feature.

39.15

Multiple fluid-operated motors:

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:

39.22,	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.
786	through 790, for a power plant where combustion products are used as motive fluid combined with a starting feature.

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.

39.162	Counter-rotatable:
	This subclass is indented under subclass 791. Plants in which two motors rotate in different directions.

39.163	Selectively connectable:
	This subclass is indented under subclass 791. Plants having at least two motors which may be selectively interconnected to provide a common power output.

39.17

With treatment between stages:

This subclass is indented under subclass 791. 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, subclasses 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.

39.181

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:

786	through 790, for a power plant where combustion products are used as motive fluid combined with a starting feature.

39.182	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.

39.183	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.

39.19

Different fluids:

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.

39.21

Plural generators, selectively operable:

This subclass is indented under subclass 793. 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.
786	through 790, for a power plant where combustion products are used as motive fluid combined with a starting feature.

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.

39.22

Varying cycle frequency relative to prime mover speed:

This subclass is indented under subclass 793. 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.

39.23

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:

794	through 795, for a power plant where combustion products are used as motive fluid combined with automatic regulation of a power output feature by control of an oxidizer.

39.24

Automatic:

This subclass is indented under subclass 793. 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, subclasses 16+ for a residual prime mover control system.
236,	Automatic Temperature and Humidity Regulation, subclasses 14 and 15, for automatic furnace control.
431,	Combustion, subclasses 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, subclasses 99 and 100 for indication or control of power plants, particularly gas turbine compressors.

39.25

Motive fluid to prime mover:

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.

39.26	Oxidizer, fuel and water or steam:
	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.

39.27

Oxidizer and fuel:

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, subclasses 319+ for speed regulators for internal combustion engines.

39.281

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, subclasses 350+ and 378+ for regulation of fuel to internal combustion engines.

39.282	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.

39.3	Water or steam:
	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.

39.34

Rotating combustion products generator and turbine:

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), subclasses 20+ for combustion products generators carried by propeller blades, the rotation being effected by the discharge of the products of combustion through reaction nozzles.

39.35

Continuous combustion type:

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".

39.37

Plural combustion products generators in ring coaxial with turbine:

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.

39.38

Intermittent combustion type:

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".

39.39

Common rotary distributing valve:

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.

39.4	Common cam member:
	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.

39.41

With exhaust pump for combustion products generator:

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.

39.42

With reversible turbine:

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.

39.43

With dual function turbine:

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:

801	through 803, for a power plant where combustion products are used as motive fluid is convertible or combined with a feature other than a combustion products generator or motor.

SEE OR SEARCH CLASS:

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

39.44

With closed pocket turbine:

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.

39.45

With gear, pressure exchanger, or screw-type compressor:

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, subclasses 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.

39.461

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, subclasses 300+ for liquid fuels for various uses.
110,	Furnaces, see (1) Note above.

39.462	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.

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

39.464

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 subclasses 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.

39.465

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.

39.47

Solid fuel containing oxidizer:

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, subclasses 530+ for pressure gas generating cartridges.
149,	Explosive and Thermic Compositions or Charges, appropriate subclasses for thermic or explosive compositions, per se.

39.48

With fluid pressure feeding of oxidizer, fuel or water:

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, subclasses 394+ for fluid pressure discharge in dispensing devices.

39.49

With air injection by fuel or steam jet:

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 subclasses 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.

[List of Patents for class 60 subclass 39.5]

39.5

With exhaust treatment:

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.

39.511

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.

39.512

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.

39.52

Exhaust gas recycling:

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, subclasses 568.11+ for devices to mix a portion of the exhaust gases with the fuel charge.

39.53

With addition of steam and/or water:

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:

39.3,	for plants including means to automatically regulate the water and/or steam.
775,	for a process where combustion products are used as motive fluid including introduction of water or steam.

39.54

Added in prime mover:

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.

39.55

Added in combustion products generator:

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, subclasses 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 subclasses 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.

39.56	Mixed in space above water:
	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.

39.57

Combustion products pass through water:

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.

39.58	Added in mixing nozzle or in turbine nozzle:
	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.

39.59

Added in separate mixing chamber:

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.

[List of Patents for class 60 subclass 39.6]

39.6

External-combustion engine type:

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 subclasses 253+ .

39.62	With plurality of combustion products generator per cylinder:
	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.

39.63

Continuous combustion:

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".

39.64

Alternate cycle:

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.
801	through 803, for a power plant where combustion products are used as motive fluid is convertible or combined with a feature other than a combustion products generator or motor.

39.76

Intermittent combustion type:

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.

39.77	Resonating:
	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.

39.78

Rotating, oscillating, or reciprocating:

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.

39.79	With fluid actuated valve:
	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.

[List of Patents for class 60 subclass 39.8]

39.8

With pressure actuated valve:

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.

39.81	With fuel metering valve:
	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.

39.821

With ignition device:

This subclass is indented under subclass 722. 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:

776	through 777, for a process where combustion products are used as a motive fluid having ignition or fuel injection after starting.
786	through 790, for a power plant where combustion products are used as motive fluid combined with a starting feature.

SEE OR SEARCH CLASS:

123,	Internal-Combustion Engines, subclasses 143+ for igniters for internal-combustion engines.
431,	Combustion, appropriate subclass for a residual fuel burner having an ignition means.

39.822	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.

39.823

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.

39.824	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.

39.825	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.

39.826	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.

39.827	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.

39.828

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.

39.83

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.
39.82,	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.
806,	for a power plant where combustion products are used as motive fluid including a combustion products generator having a turbine and cooling.

200.1

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, subclass 112.01 for turbine engine testing and subclass 147 for wind tunnel; aerodynamic wing and propeller study.
86,	Ammunition and Explosive-Charge Making, subclasses 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 subclasses 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, subclasses 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 subclasses 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 subclasses 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, subclasses 51+ for heat exchangers associated with an engine.
175,	Boring or Penetrating the Earth, subclasses 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, subclasses 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, subclasses 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 subclasses 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 and Astronautics, appropriate subclasses 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 subclasses 3.1 through 3.3for an aerial missile (including a projectile) with means to stabilize or affect the trajectory or course of the missile, subclasses 7, 12.1-12.6, 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, and subclass 113 for aircraft provided with jet reaction means to retard motion and subclass 171.1 -171.5 for a spacecraft having a propulsion system that includes a power plant of the type found in this class (60) having a significant relationship to the spacecraft.
248,	Supports, subclasses 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, subclasses 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, subclasses 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 subclasses 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, subclasses 38+ for a boat or ship propelled or steered by a reaction motor.

[List of Patents for class 60 subclass 201]

201

Rotating or cyclic movement during axial thrust:

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 and Astronautics, 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, subclasses 80+ for a motor runner having a reaction type jet discharge for causing rotation about an axis.
416,	Fluid Reaction Surfaces (i.e., Impellers), subclasses 20+ for an impeller driven by a fluid reaction jet on the working member.

[List of Patents for class 60 subclass 202]

202

Ion motor:

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, subclasses 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, subclasses 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, subclasses 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, subclasses 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, subclasses 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, subclasses 48+ for electrical (e.g., ionic) or getter type pumps.

203.1

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, subclasses 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, subclasses 317+ for propulsion systems or processes powered directly or indirectly by induced nuclear reactions.

[List of Patents for class 60 subclass 204]

204

Method of operation:

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, subclasses 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+).

[List of Patents for class 60 subclass 205]

205

By chemical reaction:

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, subclasses 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, subclasses 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, subclasses 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, subclasses 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.

GLOSSARY

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.

H₂ + Cl₂→ 2HCl

Hydrogen is considered the fuel.

CH₄ 2O₂→ CO₂ + 2H₂O

Methane is the fuel and oxygen in the

oxidizer.

BE + F₂→ 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.

BH₃ + NH₃ → BN + 3H₂

ammonia is considered the oxidizer

2LiH + F₂ → 2LiF + 2HF

fluorine is considered the oxidizer

CH₄ + 2O₂ → CO₂ + 2H₂O

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.

[List of Patents for class 60 subclass 206]

206

Utilizing indirect heat exchange:

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, subclasses 71+ for a composition designed for use in heat exchange.

[List of Patents for class 60 subclass 207]

207

Utilizing plural reaction zones within a system:

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.

[List of Patents for class 60 subclass 208]

208

Injecting air into the reaction zone:

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, subclasses 300+ for a liquid fuel mixture which may be used in air breathing reaction motors.
208,	Mineral Oils: Processes and Products, subclasses 15+ for liquid hydrocarbon mixtures such as: gasoline or kerosene.

[List of Patents for class 60 subclass 209]

209

Including using additive material:

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.

[List of Patents for class 60 subclass 210]

210

Injected separately:

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.

[List of Patents for class 60 subclass 211]

211

Injecting separate streams of fuel and oxidizer (e.g., hypergole, etc.) into the reaction zone:

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. For purposes of this and indented subclasses red fuming nitric acid, white fuming nitric acid, fuming sulfuric acid and aqueous hydrogen peroxide are arbitrarily considered pure substances.

(3) Note. For purpose of this and indented subclasses a solution of an amine base in an oxidizing acid is considered a pure substance regardless of the ratio of amine to acid.

SEE OR SEARCH CLASS:

149,

Explosive and Thermic Compositions or Charges, especially subclass 1 for a propellant composition including a normally gaseous material which is in the liquid state, subclass 36, for a propellant composition containing hydrazine and subclass 74, for a propellant composition containing oxides of nitrogen or nitric acid.

[List of Patents for class 60 subclass 212]

212

Using igniter aid:

This subclass is indented under subclass 211. Process directed to utilizing an extraneous material to aid the ignition of the fuel and oxidizer mixture in the reaction zone.

(1) Note. The igniter aid includes (1) a coating in the reaction zone which catalyzes the reaction between the fuel and oxidizer, (2) a hypergole added to the oxidizer or the fuel for starting or (3) a material separately injected into the reaction zone.

(2) Note. A patent which claims a material as a pure fuel and as a part of a fuel mixture even if it improves the ignition characteristics of the main fuel is classified in subclass 211 and cross-referenced to subclass 215.

SEE OR SEARCH THIS CLASS, SUBCLASS:

209,	for a process of utilizing an additive material in an air breathing reaction motor.

[List of Patents for class 60 subclass 213]

213

Injected separately:

This subclass is indented under subclass 212. Process directed to injecting the igniter aid into the reaction zone as a separate stream.

SEE OR SEARCH THIS CLASS, SUBCLASS:

210,	for a process of injecting a separate stream of an additive into the reaction zone of an air breathing reaction motor.

[List of Patents for class 60 subclass 214]

214

Oxidizer in the form of a mixture:

This subclass is indented under subclass 211. Process directed to injecting into the reaction zone a plurality of oxidizing substances in the form of a mixture.

(1) Note. See Notes under subclass 211 for oxidizers which are arbitrarily classified as a pure compound instead of a mixture.

[List of Patents for class 60 subclass 215]

215

Fuel in the form of a mixture:

This subclass is indented under subclass 211. Process directed to utilizing a fuel which is composed of a plurality of materials.

(1) Note. Gasoline, kerosene and the like are mixtures of numerous hydrocarbons and are considered fuel mixtures for this and indented subclasses.

SEE OR SEARCH CLASS:

44,	Fuel and Related Compositions, subclasses 300+ for liquid fuels composed of a plurality of materials.
208,	Mineral Oils: Processes and Products, subclasses 15+ for mineral oil fuels.

[List of Patents for class 60 subclass 216]

216

One component free metal:

This subclass is indented under subclass 215. Process in which the fuel contains a free metal.

(1) Note. The term "metal" includes free metal (e.g., calcium), an alloy of two or more metals (e.g., 90% Al,10% Mg), an intermetallic compound (e.g., AlNi) or a mixture of particles of two or more metals (e.g., mixture of Mg shot, Fe powder and Al turnings).

(2) Note. Processes within the scope of subclasses 205+, utilizing fuel slurries which are classified elsewhere should be cross-referenced to this subclass.

SEE OR SEARCH CLASS:

149,

Explosive and Thermic Compositions or Charges, subclass 22 for an explosive composition containing elemental boron, subclasses 37+ for an explosive composition containing a metal and an inorganic oxide, and subclass 87 for an explosive in which the fuel component contains free metal and a hydrocarbon or halohydrocarbon.

[List of Patents for class 60 subclass 217]

217

Injecting mixture of fuel and oxidizer into the reaction zone:

This subclass is indented under subclass 205. Process directed to injecting into the reaction zone a stream composed of the fuel and the oxidizer.

SEE OR SEARCH THIS CLASS, SUBCLASS:

208+,	for a process in which a mixture of fuel and air is injected into the reaction zone.
219+,	for a process in which solid propellant material is contained in the reaction zone.

SEE OR SEARCH CLASS:

149,	Explosive and Thermic Compositions or Charges, appropriate subclasses for a specific propellant composition.

[List of Patents for class 60 subclass 218]

218

Decomposing a compound in the reaction zone:

This subclass is indented under subclass 205. Process directed to decomposing a single compound in the reaction zone.

(1) Note. To come within the scope of this subclass a single compound must be broken down or rearranged to produce products which will have additional reaction effect. For example, decomposing hydrogen peroxide to produce steam and oxygen gas. For patents claiming the apparatus for producing a motive fluid which is principally steam see subclass 227.

SEE OR SEARCH CLASS:

423,	Chemistry of Inorganic Compounds, appropriate subclasses, for inorganic compounds, per se. Note especially subclasses 289+ for binary boron compounds, 407+ for hydrazkine and 584+ for hydrogen peroxide.
568,	Organic Compounds, subclasses 943+ for a nitroalkyl compound.

[List of Patents for class 60 subclass 219]

219

Using solid material in reaction zone:

This subclass is indented under subclass 205. Process directed to reacting solid material in the reaction zone.

(1) Note. Producing thrust (1) by burning a cast monopropellant in the reaction zone, (2) by jetting a fuel onto solid oxidizer in the reaction zone, (3) regulating reaction rate of the solid propellant material in the reaction zone by injecting a fluid to change the pressure in the reaction zone are nonlimiting examples of processes within the scope of this and indented subclasses.

SEE OR SEARCH THIS CLASS, SUBCLASS:

217,	for a process in which a solid propellant material is extruded into the reaction zone.

SEE OR SEARCH CLASS:

44,	Fuel and Related Compositions, appropriate subclasses for specific fuel compositions, especially subclasses 265+ for a solidified liquid fuel.
102,	Ammunition and Explosives, subclasses 283+ for powder forms of specific size or shape.
149,	Explosive and Thermic Compositions or Charges, subclasses 3+ for an explosive or thermic composition having a specific structure or arrangement of a component or the product.

[List of Patents for class 60 subclass 220]

220

Including injecting modifying fluid:

This subclass is indented under subclass 219. Process directed to injecting a modifying fluid into the reaction zone.

(3) Note. Injecting a modifying fluid into the reaction zone (1) to change the fluid pressure therein to control the reaction rate of the solid propellant material and (2) to react with the solid propellant therein are nonlimiting examples of the scope of this subclass.

SEE OR SEARCH THIS CLASS, SUBCLASS:

208+,

for a process in which air is injected into the reaction zone and subclasses 211+, for a process in which solid material and a fluid are injected into the reaction zone in separate streams.

[List of Patents for class 60 subclass 221]

221

Motive fluid principally liquid:

This subclass is indented under subclass 200.1. Apparatus wherein the motive fluid, as it leaves the ejecting means, substantially consists of a liquid.

(1) Note. The fluid leaving the ejecting means is considered to come under this definition if a substantial and important thrust component thereof is a liquid. A fluid not coming under the definition, for example, would be a gas containing a liquid mist. For such a fluid see subclass 264 for motive fluid treated with liquid, and subclass 227 for motive fluid which is principally steam.

(2) Note. The devices classified under this definition are usually boat propulsion devices in which the motive fluid leaving its ejecting means is disclosed as acting against an ambient liquid.

SEE OR SEARCH CLASS:

114,	Ships, subclass 315 for reaction motor devices adapted to operate under water having means adapted to be secured to a human for the propulsion thereof through the water.
239,	Fluid Sprinkling, Spraying, and Diffusing, for a device having an impeller for moving a fluid and an outlet through which the fluid may be discharged wherein the function of the discharged fluid relates to sprinkling, spraying, etc.
417,	Pumps, for devices not otherwise classified operable to move a liquid, however, devices claiming liquid pumping means having a disclosed use as a reaction motor is classified in Class 60.
418,	Rotary Expansible Chamber Devices, for rotary expansible chamber devices, per se. However, devices claiming liquid pumping means having a disclosed use as a reaction motor is classified in Class 60.
440,	Marine Propulsion, subclass 38 for reaction motors which propel or propel and steer a ship, and see in particular the note (5) in the definition of subclass 200.

[List of Patents for class 60 subclass 222]

222

Plural discharge outlets:

This subclass is indented under subclass 221. Apparatus having more than one means through which motive fluid from a common source may be ejected.

SEE OR SEARCH THIS CLASS, SUBCLASS:

229,	for motors having a plurality of selectively usable motive fluid outlets for discharging a fluid for the purpose of modifying the thrust direction.
263,	for motors having plural outlets for discharging fluid.

SEE OR SEARCH CLASS:

239,	Fluid Sprinkling, Spraying, and Diffusing, subclasses 265.25+ for reaction motor nozzles, per se, comprising plural controlled fluid discharge outlets.

[List of Patents for class 60 subclass 223]

223

With destruction sensing and preventing means:

This subclass is indented under subclass 200.1. Apparatus having means sensing an abnormal condition which might destroy the apparatus and functioning to take corrective action against the destructive condition.

(1) Note. This definition does not include a device which senses a normal variation in conditions to effect a control function, even though such device might be capable of sensing a suddenly presented abnormal condition. For example, a fuel control device responsive to motive fluid temperature to maintain a predetermined power output would not be classifiable under this definition but would be classified in subclasses 233+. However, a fuel control device designed to function only when the motive fluid temperature reaches a temperature above which it would be destructive to the apparatus would be classifiable under this definition.

SEE OR SEARCH CLASS:

220,	Receptacles, subclasses 89.1 through 89.4for containers having frangible or fusible pressure responsive blow out devices.

[List of Patents for class 60 subclass 224]

224

Interrelated reaction motors:

This subclass is indented under subclass 200.1. A plurality of apparatuses, each, interrelated (1) by a single means to which two or more responds, or (2) by a means or condition in one of the apparatuses upon which another apparatus is dependent for its operation.

(1) Note. A plurality of apparatuses under this definition must each include an individual means for placing its motive fluid under pressure and an individual means for ejecting said fluid. However, a device, e.g., a fan jet, having a unitary device employed to pressurize fluid for two or more ejecting means comes within this definition provided the fluids for each said ejecting means are distinguishable and not intermixed as they are being pressurized or before entering said ejecting means.

(2) Note. Concentric nozzles are not considered plural individual means for ejecting fluid if fluid from one nozzle is discharged within the confines and upstream of the discharging extremity of another of the nozzles.

(3) Note. This definition includes one reaction motor which is controlled in response to the output of another reaction motor.

(4) Note. This definition includes devices in which a component of one reaction motor is effective to operate a component (e.g., compressor) of another reaction motor.

(5) Note. A reaction motor having means by which ambient air is conducted to cool a motor part (e.g., air conducted to cool a combustion chamber, and thereafter discharged to the ambient through a nozzle, and wherein there is no disclosed indication that the coolant air may produce a thrust) is not subject matter for this subclass. Such devices may be found below particularly in subclass 266.

SEE OR SEARCH THIS CLASS, SUBCLASS:

229,	for reaction motors wherein motive fluid from a common source may be ejected selectively through one or more of several ejecting means.
244,	for devices having a single exhaust nozzle for sequentially ejecting motive fluid produced by diverse motive fluid producing means.
262,	for a device having plural means each forming a compressed gas stream, e.g., a fan-jet, wherein at least two of the streams are combined before being discharged through a common ejecting means.
263,	for devices in which the fluid from a single motive fluid pressurizing means is separated into several paths of fluid, wherein two or more of said paths are each ejected through separate ejecting means.

[List of Patents for class 60 subclass 225]

225

Sequentially operated:

This subclass is indented under subclass 224. Apparatus wherein one of the apparatuses is started after another one of the apparatuses.

(1) Note. This definition includes devices wherein one apparatus is a ram jet which is considered inoperable (i.e., incapable of producing thrust) when static, and therefore may be started only after having been given motion by another motor. These devices may be arranged serially (e.g., rocket and ram jet) having distinctive motive fluid ejecting means for each. The motive fluid ejecting means may be in the form of concentric nozzles arranged so that one may be detached from the other when one motive fluid producing means, e.g., for the rocket, is terminated to provide a new nozzle configuration for the ejection of the motive fluid from the next motive fluid producing means to be activated.

SEE OR SEARCH THIS CLASS, SUBCLASS:

246,	for reaction motors having diverse means arranged to sequentially produce a motive fluid to be discharged through a single nozzle.

226.1	Air and diverse fluid discharge from separate discharge outlets (e.g., fan jet, etc.):
	This subclass is indented under subclass 224. Apparatus wherein at least one of the motive fluids is air.

226.2	Having thrust reverser:
	This subclass is indented under subclass 226.1. Apparatus in which the air discharge outlet is supplied pressurized airflow from an fan, and in which a device or mechanism is provided for at least partially reversing the flow direction of the fan airflow to thereby reduce or reverse the thrust of the apparatus.

226.3	Having means to effect a variable bypass ratio:
	This subclass is indented under subclass 226.1. Apparatus in which the air discharge outlet is supplied pressurized airflow from a fan, and wherein a device or mechanism is provided to change the relative flow ratio between the air discharge outlet and the diverse fluid discharge outlet.

[List of Patents for class 60 subclass 227]

227

Motive fluid principally steam:

This subclass is indented under subclass 200.1. Apparatus including means for producing a motive fluid which substantially consists of steam to be ejected from the apparatus.

(1) Note. This subclass includes steam generators of the type having catalytically decomposed hydrogen peroxide (H₂O₂) and a nozzle wherein the resulting products discharged through the nozzle being predominantly steam (i.e., H₂O+O). For patents claiming the process of decomposing a compound in the reaction zone see subclass 218.

[List of Patents for class 60 subclass 228]

228

With thrust direction modifying means:

This subclass is indented under subclass 200.1. Apparatus having means which may so direct all or a portion of the motive fluid that the direction of thrust produced by the motor is altered.

(1) Note. Subject matter under this definition includes plural reaction motors having means for controlling them so as to cause a change in the direction of their resultant thrust.

SEE OR SEARCH CLASS:

239,	Fluid Sprinkling, Spraying, and Diffusing, subclasses 265.19+ for reaction motor discharge nozzles with means to control the direction of the discharge stream.
244,	Aeronautics and Astronautics, subclasses 12.1 , 23 and 29 for aircraft sustained by the thrust of a reaction motor and subclasses 15, 52 and 73+ for aircraft propelled or steered by reaction motors.

[List of Patents for class 60 subclass 229]

229

With plural selectively usable motive fluid ejecting means:

This subclass is indented under subclass 228. Apparatus having means whereby motive fluid from a common source may be selectively exhausted through one or more of several ejecting means so that a variation in the direction of the resultant thrust component may be effected.

SEE OR SEARCH THIS CLASS, SUBCLASS:

222,	for motors in which the motive fluid is principally liquid and which have a plurality of ejecting means.

SEE OR SEARCH CLASS:

239,	Fluid Sprinkling, Spraying, and Diffusing, subclasses 265.25+ for reaction motor nozzle means in which the discharge stream is directed by means of plural controlled outlets.

[List of Patents for class 60 subclass 230]

230

Jet stream deflecting means:

This subclass is indented under subclass 228. Apparatus having a means which causes the motive fluid to change direction of flow relative to the ejecting means thereby to cause a change in direction in the resultant thrust of the motor.

SEE OR SEARCH CLASS:

138,	Pipes and Tubular Conduits, subclasses 37+ for means within a pipe for changing the direction of flow of the fluid and subclass 109 for pipe shaped at the end portion to control the direction of flow of fluid before it is discharged.
244,	Aeronautics and Astronautics, subclass 52 for aircraft spoilers in combination with jet motor discharge fluid.

[List of Patents for class 60 subclass 231]

231

By secondary fluid injection:

This subclass is indented under subclass 230. Apparatus having means whereby a fluid is injected into the motive fluid stream to change the direction of flow of said motive fluid.

(1) Note. Normally devices under this subclass have a secondary fluid injected into the motive fluid at a point upstream of the nozzle outlet. However, the subclass may also include patents disclosing means to inject secondary fluid into the motive fluid downstream of the nozzle outlet if the disclosure states that the deflected motive fluid is effective to alter the direction of thrust.

SEE OR SEARCH CLASS:

137,	Fluid Handling, subclasses 803+ for means to divert or vary the flow of one stream relative to a steam receiver (1) direct contact with at least one other stream or (2) by application of an energy field directly to a stream. Devices known in the art as "fluid amplifiers" and which act to control or vary high energy flows by relatively low energy flow or fields are here included.
239,	Fluid Sprinkling, Spraying, and Diffusing, subclass 265.23 for reaction motor discharge nozzles in which the main discharge stream is deflected by a redirected portion of said stream, and subclass 127.3 for mixing a secondary fluid in the main stream.

[List of Patents for class 60 subclass 232]

232

Motive fluid outlet movable relative to motor part:

This subclass is indented under subclass 228. Apparatus having means whereby the motive fluid ejecting means, per se, may be moved to modify the direction of the entire discharge stream which passes through the ejecting means.

SEE OR SEARCH CLASS:

239,	Fluid Sprinkling, Spraying, and Diffusing, subclass 265.35 for a reaction motor nozzle in which the discharge stream is directed by adjustably aiming the nozzle.

[List of Patents for class 60 subclass 233]

233

Condition responsive thrust varying means:

This subclass is indented under subclass 200.1. Apparatus in which the thrust of the apparatus during operation may be varied by means which senses a change in (1) the static condition of the ambient or in the relationship between the apparatus and an ambient condition, or (2) a condition of an apparatus part, motive fluid or propellant of the apparatus being controlled, or (3) a condition of a motor other than a reaction motor the output of which is itself controlled responsive to a sensed change in the condition of the ambient or an internal condition.

(1) Note. Apparatus providing means which does no more than to permit the flow of fuel to a combustion chamber for starting after a certain condition has been attained, such as a certain fuel pressure or motive fluid temperature or pressure has been established, so that the motor thereafter may be fully operational, is not classified in this or indented subclasses. Such apparatus is classified below. This and indented subclasses include starting devices, however, if they further control the flow of fuel in accordance with the definition.

(2) Note. Means (i.e., for controlling fuel flow, nozzle area, etc.) controlled positively in response to a manually actuated device through a mechanical fluid linkage are not included under this definition. For example, a nozzle control responsive to fuel pressure which is controlled by manual means only is not considered to be condition responsive. Devices with such controls are classified on other features.

SEE OR SEARCH THIS CLASS, SUBCLASS:

39.24+,	for plants having combustion products generators having automatic means controlling the fuel or oxidizer flow thereto.
224+,	for interrelated reaction motors wherein the control of one reaction motor may be responsive to the condition of another reaction motor.
244,	for a reaction motor having diverse means for the production of combustion products wherein one is activated only as a result of a sensed condition of another or of a sensed ambient condition where the diverse combustion products producing means are not employed specifically to obtain a variation in thrust.
245,	for reaction motors having diverse means for the production of combustion products wherein one means is activated as a result of the depletion of the fuel supplied to another means.
250,	for reaction motors having discrete fuel supplies one of which is activated upon the depletion of another.
761	through 766, for a reaction motor having an afterburner.

SEE OR SEARCH CLASS:

431,

Combustion, subclasses 18+ for the control of a residual combustion device responsive to burner or ambient parameters. However, if fuel or oxidizer, as claimed, is controlled responsive to a condition of a disclosed but not claimed motive fluid ejecting means classification is in Class 60, Power Plants, on the basis that the structure claimed is incomplete and an ejecting means is required to complete it.

234	Solid propellant depletion control:
	This subclass is indented under subclass 233. Apparatus having a solid propellant and means to initiate or terminate the consumption thereof responsive to the condition sensing means.

[List of Patents for class 60 subclass 235]

235

Motive fluid outlet area and fuel flow control:

This subclass is indented under subclass 233. Apparatus in which the condition sensing means controls both the rate of fuel flow to combustion chamber means in the apparatus and the cross sectional area of a motive fluid ejecting means.

(1) Note. Included in this subclass are apparatuses having a fuel control means and a nozzle area control means each responsive to different sensed conditions, or both responsive to the same sensed condition.

236	Plural spool motor-compressors:
	This subclass is indented under subclass 235. Apparatus having more than one unit each of which consists of a rotary compressor means for pressurizing the motive fluid, turbine means actuated by the motive fluid and shaft means by which the turbine means may drive the compressor means, wherein the shaft means for at least two of the units are concentrically arranged.

237	Outlet area sensed to control fuel or oxidizer flow:
	This subclass is indented under subclass 235. Apparatus having means to sense the area of the motive fluid ejecting means, and in response thereto, control the fuel or oxidizer flow rate for the motor.

[List of Patents for class 60 subclass 238]

238

Motive fluid temperature sensed to control fuel flow or outlet area:

This subclass is indented under subclass 235. Apparatus in which either the fuel flow to combustion chamber means in the apparatus, or the area of the motive fluid ejecting means, or both of these together, are varied in response to a sensed change in the motive fluid temperature.

(1) Note. See glossary under subclass 205 for the definition of "fuel".

[List of Patents for class 60 subclass 239]

239

Compressor or turbine speed sensed to control fuel flow or outlet area:

This subclass is indented under subclass 235. Apparatus in which the apparatus includes a combustion chamber, a turbine and a compressor driven thereby and either the fuel flow to the combustion chamber, or the area of the motive fluid ejecting means, or both of these together, are varied as a result of a sensed change in the compressor or turbine speed.

(1) Note. See glossary under subclass 205 for the meaning of "fuel".

[List of Patents for class 60 subclass 240]

240

Oxidizer and fuel flow control:

This subclass is indented under subclass 233. Apparatus in which the condition sensing means characteristic of the apparatus including means, responsive to a sensed condition change, to control both the flow of a fuel and a combustion supporting oxidizer (e.g., air).

(1) Note. Means to alter the flow of oxidizer include, e.g., air inlet control as by a diffuser having a variable opening, variable flow retarding baffles, air bleed means, liquid oxidizer valve means or pump control means, or compressor vane setting control means. Means which controls fuel flow or an exhaust nozzle opening, resulting in a change in compressor speed and thus a change in oxidizer flow is not included in this definition. For condition responsive fuel flow and exhaust nozzle area control see subclasses 235+, 241 and 243.

(2) Note. See glossary under subclass 205 for meaning of fuel and oxidizer.

[List of Patents for class 60 subclass 241]

241

Plural burners in series:

This subclass is indented under subclass 233. Apparatus having more than one fuel burning means arranged in the motive fluid stream so that one of the fuel burning means reheats the motive fluid stream issuing from another of the means and the fuel flow to a plurality of said burning means is controlled in response to a sensed condition.

(1) Note. See glossary under subclass 205 for the meaning of fuel.

SEE OR SEARCH THIS CLASS, SUBCLASS:

243,	for a disclosure of burners in series but wherein the fuel flow to one of the burners only is controlled in response to a sensed condition.

[List of Patents for class 60 subclass 242]

242

Outlet area control:

This subclass is indented under subclass 233. Apparatus having means to vary the thrust characteristic of the apparatus during operation by varying the area of the opening through which the motive fluid may be ejected in response to a sensed condition.

SEE OR SEARCH THIS CLASS, SUBCLASS:

235+,

for motive fluid ejecting means with condition responsive means to vary the area thereof.

SEE OR SEARCH CLASS:

239,	Fluid Sprinkling, Spraying, and Diffusing, appropriate subclasses for fluid ejecting nozzles, per se, having means controlling the nozzle area for control of volumetric flow and pattern of flow.

243	Fuel flow control:
	This subclass is indented under subclass 233. Apparatus in which the condition sensing means acts to vary the thrust of the apparatus by controlling the fuel flow.

[List of Patents for class 60 subclass 244]

244

Motive fluid from diverse generators alternatively ejected through outlet:

This subclass is indented under subclass 200.1. Apparatus (A) which by relative rearrangement or adjustment of its parts or by the addition or omission of a part is so changed as to become (1) basic subject matter of this class as defined in subclass 200.1 of a different character or having a different mode of operation or (2) basic subject matter of another class, or (B) in which the apparatus as defined in subclass 200.1 is combined with means, which means if claimed, per se, would be classified in another class and which is not merely a part or subcombination of the apparatus.

(1) Note. In this subclass, for example, are apparatus having means by which motive fluid may be produced by two or more diverse producing means and ejected through a single ejecting means, and having means by which motive fluid from any one of the diverse producing means may be ejected through the ejecting means to the exclusion of the motive fluid produced by another diverse motive fluid producing means.

(2) Note. A mere fuel or ignition control means by which one motive fluid producing means may function to the exclusion of another diverse fluid producing means is not included in this definition. .

(3) Note. The following are examples of diverse motive fluid producing means: ram air fed combustion products generator (athodyd), mechanically compressed air fed combustion products generator, resonating combustion chamber, pulsating valve controlled combustion products generator; mechanically compressed air, non-air breathing combustion chamber, ion acceleration, electrical or wave energy heating means, sublimation, etc.

(4) Note. Motors having plural means for the production of a motion fluid for ejection through a single nozzle wherein one means may not function to the exclusion of another of the means are found elsewhere.

SEE OR SEARCH THIS CLASS, SUBCLASS:

224+,	for devices considered to be interrelated motors which may comprise a single casing housing diverse motive fluid producing means but employing distinct exhaust nozzle configurations for the motive fluid issuing from each motive fluid producer.
250,	for a reaction motor having plural propellants that burn sequentially.
262,	for a reaction motor having an air passage that bypasses a combustion chamber.
761	through 766, for a reaction motor having an afterburner.

[List of Patents for class 60 subclass 245]

245

Propellant supply used in one operation reduced before starting another:

This subclass is indented under subclass 244. Apparatus having means to initiate the production of motive fluid by one means after the propellant supply usable by a diverse motive fluid producing means has been reduced to a predetermined level.

SEE OR SEARCH THIS CLASS, SUBCLASS:

250,	for a motor having a plurality of sequentially combustible fuels which does not change its principle of operation as one or the other fuel is burned.

[List of Patents for class 60 subclass 246]

246

Turborocket:

This subclass is indented under subclass 200.1. Apparatus in which the means placing the motive fluid under pressure comprises a compressor driven by a turbine which is driven by combustion products egressing from a non-air breathing combustion chamber.

SEE OR SEARCH CLASS:

244,	Aeronautics and Astronautics, subclass 4 , for reaction motors having human body attaching means.

[List of Patents for class 60 subclass 247]

247

Intermittent combustion:

This subclass is indented under subclass 200.1. Apparatus in which the means for producing the motive fluid comprises an intermittently operating combustion chamber having means permitting unidirectional flow of oxidizer or fuel to said chamber.

(1) Note. Under this definition the fuel may be caused to burn intermittently either by control of the fuel flow itself or the ignition thereof, or by intermittently admitting into the combustion chamber the air or other oxidizer which supports combustion.

SEE OR SEARCH CLASS:

123,	Internal-Combustion Engines, subclass 657 for combustion chambers for internal combustion engines.

[List of Patents for class 60 subclass 248]

248

Air bypass passage:

This subclass is indented under subclass 247. Apparatus having conduit means by which ambient air may flow exteriorly of and from a point before to a point after the combustion chamber.

SEE OR SEARCH THIS CLASS, SUBCLASS:

224+,	for interrelated motors wherein air being supplied to one motor may first flow around the combustion chamber for another motor.
262,	for motors having means to flow air exteriorly of and from a point before to a point after its combustion chamber forming means.
264,	for motors having means to introduce air into the exhaust gas stream.
266,	for motors which may be cooled by an air stream.

[List of Patents for class 60 subclass 249]

249

Aerodynamic valve:

This subclass is indented under subclass 247. Apparatus in which the unidirectional flow permitting means comprises a passage means which prevents flow of combustion products therethrough from said chamber in a reverse direction due to its designed configuration and without a physical valve.

(1) Note. The unidirectional flow permitting means which offers minimum resistance to flow of fuel or oxidizers into the combustion chamber but substantially prevents reverse flow therefrom is normally a fixed orifice type restriction which presents a tortuous path to fluid attempting to leave the combustion chamber. Motors having this type of unidirectional flow permitting means are known in the art as "Valveless pulse jets".

[List of Patents for class 60 subclass 250]

250

Plural propellants to burn sequentially:

This subclass is indented under subclass 200.1. Apparatus having two or more separately contained propellants or two or more solid propellant charges having the same or distinct burning characteristics arranged so that one of said propellants may be partially or completely consumed prior to another during the operation of the reaction apparatus.

(1) Note. A solid propellant rocket having an igniter which inherently produces some thrust during ignition, is not included under this definition. See subclass 256 for devices used to ignite solid propellant charges.

(2) Note. Under this definition a plurality of solid propellant charges having the same burning characteristics would include an arrangement of individually formed masses of propellant either in physical contact with each other or separated from one another.

(3) Note. See (1) Note subclass 205 for the meaning of "propellant".

SEE OR SEARCH THIS CLASS, SUBCLASS:

225,	for a plurality of reaction motors which are interrelated and which may be operated sequentially.
245+,	for reaction motors changeable to operate by one principle of operation from another.

[List of Patents for class 60 subclass 251]

251

Solid and fluid propellant:

This subclass is indented under subclass 200.1. Apparatus in which the motive fluid is produced by the combustion of a solid propellant and a fluid propellant.

(1) Note. A gelatinous propellant is considered to be a solid and to come within this definition.

[List of Patents for class 60 subclass 252]

252

Gel propellant:

This subclass is indented under subclass 200.1. Apparatus wherein the propellant from which the motive fluid is produced is a gelatinous precipitate.

SEE OR SEARCH CLASS:

44,	Fuel and Related Compositions, subclasses 265+ for fuel which is normally liquid but rendered solid or semi-solid for better handling and transporting.

253	Solid propellant:
	This subclass is indented under subclass 200.1. Apparatus in which the propellant from which the motive fluid is produced is a solid.

[List of Patents for class 60 subclass 254]

254

Including means to terminate or regulate motive fluid production:

This subclass is indented under subclass 253. Apparatus having means to control the consumption of the propellant.

(1) Note. This definition does not include rockets wherein the fuels are packed in a particular manner or inserted with combustion enhancing or inhibiting means to produce a particular burning rate or characteristic. These apparatus are found in subclass 253.

(2) Note. This definition does not include reaction motors employing a plurality of charges which may be sequentially ignited. These devices are found above in subclass 250.

SEE OR SEARCH THIS CLASS, SUBCLASS:

224,	and in particular subclass 225 for interrelated reaction motors one of which may employ a solid propellant.
234,	for motors having condition responsive means to regulate the consumption of a solid propellant.
244+,	for motors having a means to change its principle of operation and which, at one time, may employ a solid propellant.
250+,	for motors having plural propellants which burn sequentially one or more of which may be a solid.
251,	for motors having diverse reactants one of which is a solid.

SEE OR SEARCH CLASS:

102,	Ammunition and Explosives, subclasses 283+ for shapes or mechanical structures of grains, sticks, or bars of explosive material arranged to modify the manner of burning.

[List of Patents for class 60 subclass 255]

255

Including propellant support means:

This subclass is indented under subclass 253. Apparatus having means to position, hold or support the propellant.

(1) Note. A mere wall or casing without any special modification for positioning, holding or supporting the propellant is not included. See Class 239, Fluid Sprinkling, Spraying, and Diffusing, subclass 302.

[List of Patents for class 60 subclass 256]

256

Including ignition means:

This subclass is indented under subclass 253. Apparatus having means to initiate propellant combustion.

SEE OR SEARCH CLASS:

102,	Ammunition and Explosives, subclass 202 for means for igniting a missile propellant.

[List of Patents for class 60 subclass 257]

257

Liquid oxidizer:

This subclass is indented under subclass 200.1. Apparatus in which thrust is produced by the combustion of (1) a monopropellant or (2) an oxidizer and a fuel, the oxidizer being supplied to the combustion zone in a liquid state.

(1) Note. This definition is intended to provide an art collection of nonair breathing motors (i.e., rockets) employing an oxidant supplied to the motor in a liquid state. However, no special structure need be claimed for classification in this subclass. Patents whose disclosure or claims relate to the described art group are considered to come under this definition.

(2) Note. A broad disclosure that liquid oxidizer, two or more liquid propellants or liquid monopropellant are used in the motor or that the motor is of the "liquid propellant or liquid reactant" nonair breathing type is classifiable under this definition.

SEE OR SEARCH THIS CLASS, SUBCLASS:

240,	for motors having oxidizers stored as a liquid with sensed condition responsive means for controlling oxidizer flow.

258	Including injector means:
	This subclass is indented under subclass 257. Apparatus having means to inject the oxidizer into the combustion zone where it is to be consumed during the combustion process.

259	Including pressurizing means:
	This subclass is indented under subclass 257. Apparatus having means to increase the pressure of the oxidizer or monopropellant so that it may be introduced into the motive fluid producing area (e.g., burner).

[List of Patents for class 60 subclass 260]

260

Including heating means:

This subclass is indented under subclass 257. Apparatus having means by which a liquid oxidizer or monopropellant may be heated before it is introduced into the motive fluid producing means.

SEE OR SEARCH THIS CLASS, SUBCLASS:

267,	for motors having a means to exchange heat between a solid body and a liquid.

[List of Patents for class 60 subclass 262]

262

Air passage bypasses combustion chamber:

This subclass is indented under subclass 200.1. Apparatus in which an air stream is compressed and led into a combustion chamber in which motive fluid is produced, comprising a passage for causing a portion of the air, after it has been compressed, to avoid entry into the combustion chamber and be led back into the stream of motive fluid from the combustion chamber before it is ejected into the ambient.

SEE OR SEARCH THIS CLASS, SUBCLASS:

224,	for devices having means to cause a portion of a compressed gas stream to bypass a combustion chamber or other component acting upon the stream together with separate ejecting means for each of two or more of the streams formed.
246,	for a device having a compressed air stream bypassing a nonair breathing combustion chamber.
248,	for a device having an air passage which bypasses an intermittent combustion chamber.

[List of Patents for class 60 subclass 263]

263

Plural motive fluid generating means or plural outlets:

This subclass is indented under subclass 200.1. Apparatus having (1) two or more motive fluid producing means, means to combine the motive fluid issuing from said producing means, and either single or plural ejecting means through which said combined motive fluid may pass or (2) two or more motive fluid ejecting means receiving motive fluid from a single motive fluid producing means.

(1) Note. Concentric nozzles are not considered plural if fluid from one nozzle is discharged within the confines and upstream of the discharging extremity of another of the nozzles.

SEE OR SEARCH THIS CLASS, SUBCLASS:

201,	for reaction motors arranged to turn about an axis when in operation and having a plurality of motive fluid ejecting means.
224+,	for a plurality of reaction motors which are interrelated either because one is responsive to a condition of another or two or more reaction motors are responsive to a single means.
229,	for motors having plural selectively usable motive fluid ejecting means to vary the thrust magnitude.
262,	for motors having plural combustion chambers but wherein passage means is provided for the ambient air supply for one combustion chamber which extends from a point before to a point after another combustion chamber.

[List of Patents for class 60 subclass 264]

264

Including motive fluid treating means:

This subclass is indented under subclass 200.1. Apparatus having means whereby a physical characteristic of a stream of pressurized motive fluid may be changed by the introduction of a substance into said stream to react or mix therewith.

SEE OR SEARCH THIS CLASS, SUBCLASS:

231,	for motors having thrust direction modifying means employing a means to inject a fluid into the motive fluid ejecting means.
246,	for motors having means to mix pressurized air from the effluent from a nonair breathing combustion chamber.
248,	for reaction motors having means to bypass air around an intermittent combustion chamber and to mix said air with combustion products issuing from said combustion chamber.
261,	for a motor having means to add oxidizer or fuel to an atmosphere of previously formed combustion products to promote further burning.
265,	for motors having means to flow a film of fluid on a motor component surface between said surface and the motive fluid to cool the component, and means whereby the fluid may ultimately combine with the motive fluid.

SEE OR SEARCH CLASS:

239,	Fluid Sprinkling, Spraying, and Diffusing, subclass 127.3 for means to mix a cooling fluid with the main discharge stream in a nozzle of a reaction motor, and subclass 265.17 for a means to add a secondary fluid to the main stream upstream of the nozzle outlet.

[List of Patents for class 60 subclass 265]

265

Means to flow film on surface:

This subclass is indented under subclass 200.1. Apparatus having means by which a fluid film, other than air, may be caused to sweep a surface of the apparatus between said surface and the motive fluid presented to said surface.

(1) Note. Included in this definition is a fluid film formed by ablatable material on a motive fluid engageable surface.

SEE OR SEARCH THIS CLASS, SUBCLASS:

257	through 260, for a reaction motor using a liquid oxidizer, especially 258 for an injecting means, that could include the liquid oxidizer flowing along walls of a combustion chamber.
761	through 766, for a reaction motor having an afterburner that could include the fuel flowing along walls of a combustion chamber.

SEE OR SEARCH CLASS:

239,	Fluid Sprinkling, Spraying, and Diffusing, subclass 265.15 for reaction motor nozzles having an erodible, frangible or fusible part.

[List of Patents for class 60 subclass 266]

266

Including heat exchange means:

This subclass is indented under subclass 200.1. Apparatus having means to enhance the transfer of heat between a solid body and a fluid flowing in contact therewith.

SEE OR SEARCH THIS CLASS, SUBCLASS:

246,	for turborockets having means to bypass air around a nonair breathing combustion chamber.
248,	for an intermittent combustion motor in which bypassed air may be used as a coolant.
262,	for motors in which a part of the compressed gas may be bypassed around a motor part to cool said part.
264,	for motors having a substance to be mixed with the motive fluid but which may also be used to cool a part of said motor.

SEE OR SEARCH CLASS:

52,	Static Structures (e.g., Buildings), subclass 232 for a structural component having chemically reactable layers or components which may change physically or chemically with variations in ambient conditions such as heat or moisture.
62,	Refrigeration, subclasses 467+ for apparatus comprising means to cause a cooling effect by producing a change in the condition or state of a material.
239,	Fluid Sprinkling, Spraying, and Diffusing, subclass 127.1 for reaction motor discharge nozzles having cooling jackets.
244,	Aeronautics and Astronautics, subclass 117 for aircraft having an ablatable surface.

267	For a liquid:
	This subclass is indented under subclass 266. Apparatus wherein said fluid is a liquid.

[List of Patents for class 60 subclass 268]

268

Including counter rotating rotors:

This subclass is indented under subclass 200.1. Apparatus having a plurality of rotary means two or more of which rotate in opposite directions, each rotary means having a means to compress a propellant and a means driving said rotary means.

SEE OR SEARCH THIS CLASS, SUBCLASS:

236,	for reaction motors having counter rotating turbine rotors with condition responsive means which may control the fuel supply and motive fluid ejecting means opening.

SEE OR SEARCH CLASS:

415,	Rotary Kinetic Fluid Motors or Pumps, subclasses 60+ for counter rotating rotors in a device of the type there classified.
416,	Fluid Reaction Surfaces (i.e., Impellers), subclasses 128+ for oppositely rotating impellers, per se.

[List of Patents for class 60 subclass 269]

269

Including mechanical air compressor or air flow inducing means:

This subclass is indented under subclass 200.1. Apparatus wherein the pressure of air is increased by mechanical means or by means of a pressurized fluid, said air being used as a propellant or as the motive fluid.

(1) Note. Included in this definition are reaction motors which include an impeller for moving a fluid and having an outlet for discharging said fluid having a sole disclosed function to produce a thrust.

SEE OR SEARCH THIS CLASS, SUBCLASS:

221+,	for reaction motors having shrouded impellers wherein water is the medium moved.
268,	for motors having counter rotating turbine rotors driving plural compressor elements.

SEE OR SEARCH CLASS:

239,	Fluid Sprinkling, Spraying, and Diffusing, subclass 265.11 for a device having an impeller for moving a fluid and an outlet through which the fluid may be discharged wherein a function of the discharged fluid relates to spraying, sprinkling, etc.

[List of Patents for class 60 subclass 272]

272

INTERNAL COMBUSTION ENGINE WITH TREATMENT OR HANDLING OF EXHAUST GAS:

This subclass is indented under the class definition. Subject matter having an engine in which fuel is burned in an expansible chamber to produce work and in which at least some of the combusted material going to discharge is handled or treated after it reaches a point where the handling or treatment is more than that necessary to remove the material from the chamber.

SEE OR SEARCH THIS CLASS, SUBCLASS:

39.5+,	for the treatment of combustion products making up the exhaust of a gas turbine; subclasses 64+ for the treatment of the exhaust of an engine driven by a single fluid; and subclasses 200+ for a power plant comprising a combustion products generator and a combustion products directing reaction nozzle.
228+,	for a reaction motor with thrust modifying means.
595,	for a free piston type internal combustion engine, the exhaust of which drives a motor.
597+,	for a fluid motor driven by the exhaust or waste heat of an internal combustion engine.

SEE OR SEARCH CLASS:

123,	Internal-Combustion Engines, subclasses 568.11+ , for an internal combustion engine having a charge forming device that may be heated by exhaust gas; or in which exhaust gas is mixed with the engine fuel; subclass 142.5 for an internal combustion engine in which various parts of the engine exchange heat; and appropriate subclass for a residual internal combustion engine with the exhaust handled or treated as necessary to evacuate the combustion chamber or to modify operation of the engine.
180,	Motor Vehicles, subclass 296 for a motor vehicle having a specific motor-to-body-frame relationship and wherein the vehicle includes means on the motor or body frame for handling exhaust from the motor; subclass 309 for a motor vehicle which includes means for handling exhaust from its motor; and subclass 89.2 for a body for a motor vehicle, which body includes means for handling the exhaust of a motor.
181,	Acoustics, subclasses 213+ for a muffler, per se.

[List of Patents for class 60 subclass 273]

273

Methods:

This subclass is indented under subclass 272. Processes of treating or handling the materials discharging to atmosphere or to an external device from the combustion chamber of an internal combustion engine.

SEE OR SEARCH CLASS:

423,	Chemistry of Inorganic Compounds, subclasses 212+ for a process of purifying a gas that is nominally the exhaust from an internal combustion engine.

274	Anti-pollution:
	This subclass is indented under subclass 273. Processes in which the handling or treatment serves to remove or destroy harmful materials in the exhaust gas.

[List of Patents for class 60 subclass 275]

275

By electrolysis, electrical discharge, electrical field, or vibration generator:

This subclass is indented under subclass 272. Apparatus in which the exhaust gas is treated by a sonic or super-sonic vibration generator, an electrical field device, electrolysis, or by an electrical discharge.

(1) Note. An electrical igniter is not regarded as an electrical field or discharge type gas treater.

SEE OR SEARCH CLASS:

95,	Gas Separation: Processes, subclasses 57+ for processes of gas separation involving an electric or electrostatic field.
96,	Gas Separation: Apparatus, subclasses 15+ for apparatus for gas separation involving an electric or electrostatic field.

[List of Patents for class 60 subclass 276]

276

Having means analyzing composition of exhaust gas:

This subclass is indented under subclass 272. Apparatus including structure analyzing the chemical composition of the exhaust gas and exerting a control responsive to the determined value or giving an indication of the determined value.

SEE OR SEARCH CLASS:

73,	Measuring and Testing, subclasses 23+ for a gas analyzer, per se.
200,	Electricity: Circuit Makers and Breakers, subclass 61.03 for a smoke responsive switch.
324,	Electricity: Measuring and Testing, appropriate subclass for apparatus testing the electrical properties of gases.
422,	Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing, subclass 83 for gas analyzers.
431,	Combustion, subclass 76 for a fuel burner controlled by a means analyzing the composition of its combustion products.

[List of Patents for class 60 subclass 277]

277

Having sensor or indicator of malfunction, unsafeness, or disarray of treater (e.g., fusible link, etc.):

This subclass is indented under subclass 272. Apparatus, with means (1) that prevents operation if a necessary state or condition is not sensed or indicated (2) that stops operation if a malfunction or dangerous condition is sensed (3) that takes protective action to protect a system element responsive to a sensed malfunction or dangerous condition (4) or that acts to inform the operator of a dangerous state or malfunction.

SEE OR SEARCH CLASS:

340,	Communications: Electrical, subclasses 500+ for electrical automatic condition responsive indicating systems.

[List of Patents for class 60 subclass 278]

278

Material from exhaust structure fed to engine intake:

This subclass is indented under subclass 272. Apparatus having (1) structure by which a part of the gas discharged from the combustion chamber is returned to become a constituent of the engine feed and another part is handled or treated as it is discharged as exhaust gas or (2) structure by which the combustion chamber discharge gas is cooled, purified or separated; and a part of the cooled, purified or separated engine discharge is returned as engine feed and another part is discharged as exhaust gas.

SEE OR SEARCH CLASS:

123,	Internal-Combustion Engines, subclass 568.11 for an internal combustion engine having means to return a part of the exhaust gas switching, therefrom back to the engine intake and wherein no means are provided to treat said gas.

279	Separated reactive constituent of exhaust fed to engine:
	This subclass is indented under subclass 278. Apparatus in which the combustion chamber discharge is separated into two streams, one richer in reactive material than the other, the enriched part of the separated combustion chamber discharge being returned to the engine and the stream reduced in reactive components being discharged as exhaust gas.

[List of Patents for class 60 subclass 280]

280

Having auxiliary device mechanically driven by exhaust gas:

This subclass is indented under subclass 272. Apparatus including a mechanism or structure driven by the flow of the engine exhaust gas serving to perfect the operation of the engine.

SEE OR SEARCH THIS CLASS, SUBCLASS:

597+,

for an internal combustion engine having a motor driven by exhaust from the internal combustion engine.

[List of Patents for class 60 subclass 281]

281

Having exhaust gas collection and storage, or use as a pressure fluid source:

This subclass is indented under subclass 272. Apparatus in which the handling means includes a collection and storage reservoir, or a flow line maintaining the exhaust pressure and connected to a point using exhaust gases as a pressurized motive fluid.

SEE OR SEARCH THIS CLASS, SUBCLASS:

613,	for an internal combustion engine having a motor driven by its exhaust gases and having means to temporarily store the gases prior to their entry into the motor.

SEE OR SEARCH CLASS:

239,	Fluid Sprinkling, Spraying, and Diffusing, subclass 129 , for a system using exhaust gas to heat and spray an external material.

[List of Patents for class 60 subclass 282]

282

By means producing a chemical reaction of a component of the exhaust gas:

This subclass is indented under subclass 272. Apparatus having means for chemically reacting at least one of the constituent materials of the combustion products to produce a substance less harmful to living organisms.

SEE OR SEARCH CLASS:

422,	Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing, subclasses 168+ for a chemical or catalytic reactor for treating exhaust gas.
423,	Chemistry of Inorganic Compounds, subclasses 212+ for a process of purifying a mixture that is nominally the exhaust of an internal combustion engine.

283	With means handling crankcase, carburetor, or gas tank vapor:
	This subclass is indented under subclass 282. Apparatus with structure by which the fumes from the crankcase of the engine, or fuel vapors from the carburetor or fuel tank are handled or treated in conduction with the engine exhaust gas.

284	Automatic or timed reactor purge or heat-up in engine starting operation:
	This subclass is indented under subclass 282. Apparatus in which there is a sequence by which the engine is brought into full operation after start initiation without manual intervention; the sequence including a purge period or operation on the reactor, or a special operation to bring the reactor to an effective reacting temperature.

285	Engine fuel, air, or ignition controlled by sensor of reactor condition:
	This subclass is indented under subclass 282. Apparatus including a means that senses a condition of the reactor and actuates a device controlling the feed to, or ignition of the engine.

[List of Patents for class 60 subclass 286]

286

Condition responsive control of heater, cooler, igniter, or fuel supply of reactor:

This subclass is indented under subclass 282. Apparatus including a condition responsive device controlling a means heating the reactor, a means igniting the exhaust gas in the reactor, a means cooling the reactor, or a means supplying fuel to the reactor.

SEE OR SEARCH THIS CLASS, SUBCLASS:

284,	for an automatic purge or heat-up of an exhaust gas treating reactor in an engine starting sequence.

[List of Patents for class 60 subclass 287]

287

Condition responsive control of reactor feed, pressure, or by-pass:

This subclass is indented under subclass 282. Apparatus including a means sensing a condition of the apparatus and exerting a control on a means feeding a fluid to the reactor, of the pressure of the reactor, or on a means by-passing the reactor.

SEE OR SEARCH THIS CLASS, SUBCLASS:

285,	for apparatus in which the engine feed or ignition is controlled by a means sensing a condition of the reactor.

288	Exhaust gas diverted from reactor or treating agent mixer:
	This subclass is indented under subclass 287. Apparatus in which the condition responsive means control structure selectively directing exhaust from the engine through the reaction device or a device by which oxidizer is entrained for reaction; or through a branch or bypass avoiding such device.

289	Air feed to reactor modulated or diverted by control:
	This subclass is indented under subclass 287. Apparatus controlling the delivery of reactive air to the reactor.

290	Responsive to engine speed or intake manifold pressure:
	This subclass is indented under subclass 289. Apparatus in which the feed of reactive is controlled by a means responsive to the speed of the engine or to the pressure in the intake manifold of the engine.

291	Of or by pressure in reactor or of engine exhaust:
	This subclass is indented under subclass 287. Apparatus in which there is (1) a means controlling the pressure in the reactor or in the exhaust gas being fed to the reactor; or (2) a means sensing the pressure in the reactor or of the exhaust gas being fed to the reactor and controlling an element of the apparatus.

292	Valve at reactor outlet controlled:
	This subclass is indented under subclass 291. Apparatus in which a valve controlling the discharge from the reactor to the atmosphere is actuated by a means sensing the pressure in the reactor.

293	Check valve feeds air to exhaust system:
	This subclass is indented under subclass 291. Apparatus in which a valve responsive to the difference in pressure between that of the reactor and the atmosphere open to feed reactive air to the reactor when the pressure in the reactor is below atmospheric pressure.

294	Reactor control correlated with cyclic or external engine control:
	This subclass is indented under subclass 282. Apparatus in which a control means that affects operation of the reactor is mechanically connected to the throttle of the engine or to a cyclically controlled element of the engine to be moved along with the throttle or element.

295	Having means for regenerating, replacing, or feeding liquid or solid reagent or catalyst:
	This subclass is indented under subclass 282. Apparatus with structure for cleaning, regenerating, replacing or otherwise restoring used, contaminated, or consumed catalytic material or other solid or liquid treating agent or reactant.

296	Flow reversing structure:
	This subclass is indented under subclass 295. Apparatus in which cleaning or regenerating is accomplished by reversing the flow of fluid through the agent, reactant or catalytic material.

297	Reactor plus a washer, sorber or mechanical separator:
	This subclass is indented under subclass 282. Apparatus having, in addition to the reactor, means to mechanically remove, solid or liquid particles from the exhaust gas; to wash the exhaust gas; or to absorb or adsorb material from the exhaust gas.

298	With means cooling reactor or reactor feed:
	This subclass is indented under subclass 282. Apparatus having structure by which heat is removed from the reactor or from the feed to the reactor, generally to prevent overheating of the reactor.

[List of Patents for class 60 subclass 299]

299

Using a catalyst:

This subclass is indented under subclass 282. Apparatus in which the exhaust gas is passed over or through catalytic material to produce the reaction.

SEE OR SEARCH CLASS:

422,	Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing, subclass 168 for a chemical or catalytic reactor for treating exhaust gas.

300	Having a means for heating the catalyst:
	This subclass is indented under subclass 299. Apparatus with an external means for supplying heat to the catalyst to raise it to an operative temperature.

301	Reducing type catalyst:
	This subclass is indented under subclass 299. Apparatus in which the reaction assisted by the catalyst is of the reduction type, i.e., the removal of oxygen from the substance being treated.

302	Catalyst in engine manifold or at exhaust port:
	This subclass is indented under subclass 299. Apparatus in which the catalyst is positioned directly in the exhaust manifold or between the manifold and the combustion chamber of the engine.

303	Having heater, igniter, or fuel supply for reactor:
	This subclass is indented under subclass 282. Apparatus in which the reaction of the exhaust gas is initiated or maintained by a heater, an igniter, or a supplemental feed of fuel.

304	Oxidizer feed passage at engine exhaust valve, manifold or port:
	This subclass is indented under subclass 282. Apparatus including structure by which air is fed to the exhaust gas at a region immediately associated with an engine exhaust valve or port, whereby the high temperature produced by combustion in the engine produces the reaction.

305	Distributed to plural individual ports or valves:
	This subclass is indented under subclass 304. Apparatus in which oxidizer from a common supply structure is fed separately to the exhaust valves or ports of spaced engine combustion chambers.

306	To port zone and downstream of port:
	This subclass is indented under subclass 304. Apparatus in which oxidizer is fed both to a region of reaction adjacent the combustion chamber and to a reactor downstream of and spaced from the port region.

307	Pressurizing means feeds reactive air to reactor:
	This subclass is indented under subclass 282. Apparatus having a pump or other fluid impelling structure feeding air into the combustion products from the engine to react chemically therewith.

[List of Patents for class 60 subclass 308]

308

Exhaust actuated air aspirator:

This subclass is indented under subclass 307. Apparatus in which the air is caused to flow by an aspirating effect of the exhaust gas.

SEE OR SEARCH CLASS:

123,	Internal-Combustion Engines, subclass 41.64 for an internal combustion engine in which cooling air is aspirated across the engine by a jet pump generally powered by exhaust gas.

[List of Patents for class 60 subclass 309]

309

Having retainer or flow director for exhaust gas condensate:

This subclass is indented under subclass 272. Apparatus with structure for receiving or handling liquid condensed from the exhaust gases.

SEE OR SEARCH CLASS:

91,	Motors: Expansible Chamber Type, subclasses 236+ , for a cyclically operable expansible chamber motor having plural exhaust passages, for example, separate air and condensate discharge passages.

[List of Patents for class 60 subclass 310]

310

Treated by washing, or having liquid contact structure:

This subclass is indented under subclass 272. Apparatus in which the exhaust gas is treated by being washed by liquid, or is handled by structure within which it comes into contact with liquid.

SEE OR SEARCH CLASS:

181,	Acoustics, subclass 235 , for a muffler having an underwater discharge; and subclasses 221 and 260+, for a muffler into which liquid is fed to assist in muffling the sound.
261,	Gas and Liquid Contact Apparatus, appropriate subclass for gas and liquid contact apparatus not specialized to handling the exhaust of an internal combustion engine.

[List of Patents for class 60 subclass 311]

311

By sorber or mechanical separator:

This subclass is indented under subclass 272. Apparatus treating the exhaust gases by absorbing or adsorbing one of the liquid or gaseous components; or by separating a liquid or solid component by a filter, a centrifugal device, or a gravitational device.

SEE OR SEARCH THIS CLASS, SUBCLASS:

299+,

for apparatus in which exhaust gas is passed into or through a catalytic bed that may also filter the gas or sorb one of its components.

SEE OR SEARCH CLASS:

55,	Gas Separation, appropriate subclass, for a gas separator of general utility.
96,	Gas Separation: Apparatus, for gas separation apparatus, per se.

[List of Patents for class 60 subclass 312]

312

Pulsed, timed, tuned or resonating exhaust:

This subclass is indented under subclass 272. Apparatus correlating, or correlated with the pressure waves or pulses produced by the regular, intermittent discharge from an engine"s exhaust port or ports.

SEE OR SEARCH CLASS:

181,	Acoustics, subclasses 277+ , for a muffler, per se, tuned to silence or muffle pressure pulses.

313	Correlated exhausts from plural cylinders:
	This subclass is indented under subclass 312. Apparatus receiving pressure pulses from successively firing cylinders.

[List of Patents for class 60 subclass 314]

314