CPC Definition - Subclass F02B

Last Updated Version: 2019.05
INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (cyclically operating valves therefor F01L; lubricating internal-combustion engines F01M; gas-flow silencers or exhaust apparatus therefor F01N; cooling of internal-combustion engines F01P; internal-combustion turbines F02C; plants in which engines use combustion products F02C, F02G)
Definition statement

This place covers:

Engines characterised by the working fluid to be compressed or characterised by the type of ignition

Engines characterised by the method of introducing liquid fuel into cylinders

Engines characterised by precombustion chambers or air-storage chambers, or characterised by special shape or construction of combustion chambers to improve operation

Engines characterised by provision for charging or scavenging

Engines characterised by provision of driven charging or scavenging pumps

Engines operating on non-liquid fuels; Plants including such engines, i.e. combinations of the engine with fuel-generating apparatus

Methods of operating engines involving specific pre-treating of, or adding specific substances to, combustion air, fuel, or fuel-air mixture of the engines, and not otherwise provided for

Internal-combustion aspects of rotary-piston or oscillating-piston engines

Internal combustion aspects of reciprocating-piston engines with movable cylinders

Adaptations of engines for special use; Combinations of engines with devices other than engine parts or auxiliaries

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Apparatus for generating fuel, e.g. gas, see the relevant classes, e.g.

C10

Rotary-piston or oscillating-piston

F01C

Non-positive-displacement type

F01D

Steam engines plants

F01K

Cyclically operating valves for machines or engines

F01L

Lubrication of machines or engines in general

F01M

Exhaust Apparatus

F01N

Cooling of Engines

F01P

Gas-turbine plants

F02C

Use of waste-heat of combustion engines

F02G

Carburettors, fuel-injection apparatus

F02M

Apparatus for performing such pretreatments or additions

F02M

Crankshafts, crossheads, connecting-rods

F16C

Flywheels

F16F

Gearings for interconverting rotary motion and reciprocating motion in general

F16H

Pistons, piston rods, cylinders for engines in general

F16J

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

engine

a device for continuously converting fluid energy into mechanical power. Thus, this term includes, for example, steam piston engines or steam turbines, per se, or internal-combustion piston engines, but it excludes single-stroke devices. "Engine" also includes the fluid-motive portion of a meter unless such portion is particularly adapted for use in a meter;

pump

a device for continuously raising, forcing, compressing, or exhausting fluid by mechanical or other means. Thus, this term includes fans or blowers;

machine

a device which could equally be an engine and a pump, and not a device which is restricted to an engine or one which is restricted to a pump;

positive displacement

the way the energy of a working fluid is transformed into mechanical energy, in which variations of volume created by the working fluid in a working chamber produce equivalent displacements of the mechanical member transmitting the energy, the dynamic effect of the fluid being of minor importance, and vice versa ;

non-positive displacement

the way the energy of a working fluid is transformed into mechanical energy, by transformation of the energy of the working fluid into kinetic energy, and vice versa ;

oscillating-piston machine

a positive-displacement machine in which a fluid-engaging work-transmitting member oscillates. This definition applies also to engines and pumps;

rotary-piston machine

a positive-displacement machine in which a fluid-engaging work-transmitting member rotates about a fixed axis or about an axis moving along a circular or similar orbit. This definition applies also to engines and pumps;

rotary piston

the work-transmitting member of a rotary-piston machine and may be of any suitable form, e.g., like a toothed gear;

cooperating members

the "oscillating piston" or "rotary piston" and another member, e.g., the working-chamber wall, which assists in the driving or pumping action;

movement of the co-operating members

is to be interpreted as relative, so that one of the "co-operating members" may be stationary, even though reference may be made to its rotational axis, or both may move;

teeth or tooth equivalents

include lobes, projections or abutments;

internal-axis type

that the rotational axes of the inner and outer co-operating members remain at all times within the outer member, e.g., in a similar manner to that of a pinion meshing with the internal teeth of a ring gear;

free piston

a piston of which the length of stroke is not defined by any member driven thereby;

cylinders

positive-displacement working chambers in general. Thus, this term is not restricted to cylinders of circular cross-section;

main shaft

the shaft which converts reciprocating piston motion into rotary motion or vice versa ;

plant

an engine together with such additional apparatus as is necessary to run the engine. For example, a steam engine plant includes a steam engine and means for generating the steam;

working fluid

the driven fluid in a pump or the driving fluid in an engine. The working fluid can be in a compressible, gaseous state, called elastic fluid, e.g. steam; in a liquid state; or in a state where there is coexistence of an elastic fluid and liquid phase.

steam

includes condensable vapours in general, and "special vapour" is used when steam is excluded;

reaction type

as applied to non-positive-displacement machines or engines means machines or engines in which pressure/velocity transformation takes place wholly or partly in the rotor. Machines or engines with no, or only slight, pressure/velocity transformation in the rotor are called "impulse type".

Engines characterised by fuel-air mixture compression (characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition F02B 11/00; characterised by precombustion chambers F02B 19/00; characterised by air-storage chambers F02B 21/00; characterised by special shape or construction of combustion chambers F02B 23/00)
Definition statement

This place covers:

Engine working on the compression of a homogeneous mixture of air and fuel.

The scope of this group is very wide so that it only makes sense to classify specific documents in the subgroups for which there is no other relevant classification.

References
Limiting references

This place does not cover:

Characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition

F02B 11/00

Characterised by precombustion chambers

F02B 19/00

Characterised by air-storage chambers

F02B 21/00

Characterised by special shape or construction of combustion chambers

F02B 23/00

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

HCCI

Homogeneous Charge Compression Ignition

PCCI

Premixed Charge Compression Ignition

with positive ignition (with non-timed positive ignition F02B 9/06)
Definition statement

This place covers:

This group covers engines with positive ignition.

Just like F02B 1/00 the scope is too wide to classify all spark ignition (SI) engines.

Because of lack of discrimination of this class, it is in use primarily to classify engines running on alcohol. (ethanol).

with fuel-air mixture admission into cylinder
References
Limiting references

This place does not cover:

Direct injection petrol engines

F02B 2075/125

Methods of operating
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Controlling engines

F02D

with separate admission of air and fuel into cylinder
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

With compression ignition

F02B 1/12

Methods of operating
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Controlling combustion engines

F02D

with compression ignition (with fuel-air charge ignited by compression ignition of an additional fuel F02B 7/00)
Definition statement

This place covers:

Engines operating on "homogeneous" mixed air-fuel.

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

HCCI

Homogeneous Charge Compression Ignition

PCCI

Premixed Charge Compression Ignition

Engines characterised by air compression and subsequent fuel addition (characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition F02B 11/00; characterised by precombustion chambers F02B 19/00; characterised by air-storage chambers F02B 21/00; characterised by special shape or construction of combustion chambers F02B 23/00)
Definition statement

This place covers:

Engines characterised by air compression and subsequent fuel addition. E.g. diesel engines, but this group also covers engines with air compression and subsequent gasoline fuel addition as in gasoline direct injection.

References
Limiting references

This place does not cover:

Characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition

F02B 11/00

Characterised by precombustion chambers

F02B 19/00

Characterised by air-storage chambers

F02B 21/00

Characterised by special shape or construction of combustion chambers

F02B 23/00

with positive ignition (with non-timed positive ignition F02B 9/06)
Definition statement

This place covers:

Air compressing engines with spark ignition.

References
Limiting references

This place does not cover:

With non-timed positive ignition

F02B 9/06

Methods of operating
References
Limiting references

This place does not cover:

Controlling combustion engines

F02D

Electrical control of combustion engines

F02D 41/00

with compression ignition (F02B 13/02 takes precedence; with fuel-air charge ignited by compression ignition of an additional fuel F02B 7/00)
Definition statement

This place covers:

In short: The Diesel engine. Preferably only deviations of the Diesel engine should be classified here.

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Methods of operating (F02B 3/12 takes precedence)
Definition statement

This place covers:

The method of operating should be a deviation of the "normal Diesel". Normally the method of operating is already embodied in the engine itself.

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References
Limiting references

This place does not cover:

Control of combustion engine

F02D

with intermittent fuel introduction
Definition statement

This place covers:

More than one injection per cycle or very closely spaced multiple injections

References
Limiting references

This place does not cover:

Controlling fuel injection of the high pressure type with multiple injections

F02D 41/402

Fuel injection apparatus with each cyclic delivery being separated into two or more parts

F02M 45/02

Engines characterised by positive ignition (F02B 1/02, F02B 3/02 take precedence; with non-timed positive ignition F02B 9/06; characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition F02B 11/00; characterised by precombustion chambers F02B 19/00; characterised by air-storage chambers F02B 21/00; characterised by special shape or construction of combustion chambers F02B 23/00)
Definition statement

This place covers:

Engines characterised by positive ignition.

References
Limiting references

This place does not cover:

Engines characterised by fuel-air mixture compression with positive ignition

F02B 1/02

Engines characterised by air compression and subsequent fuel addition with positive ignition

F02B 3/02

Informative references

Attention is drawn to the following places, which may be of interest for search:

Engines with non-timed positive ignition, e.g. with hot-spots

F02B 9/06

Engines characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition

F02B 11/00

Engines characterised by special shape or construction of combustion chambers

F02B 23/00

Methods of operating
References
Limiting references

This place does not cover:

Control of combustion engines

F02D

Engines characterised by the fuel-air charge being ignited by compression ignition of an additional fuel (characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition F02B 11/00; characterised by precombustion chambers F02B 19/00; characterised by air-storage chambers F02B 21/00; characterised by special shape or construction of combustion chambers F02B 23/00)
Definition statement

This place covers:

Engines characterised by the fuel-air charge being ignited by compression ignition of an additional fuel. E.g. a compressed fuel-air mixture being ignited by directly injecting a diesel fuel.

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Engines characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition

F02B 11/00

Engines characterised by precombustion chambers

F02B 19/00

Engines characterised by air-storage chambers

F02B 21/00

Engines characterised by special shape or construction of combustion chambers

F02B 23/00

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Pilot injection

The injection of an additional fuel for ignition of a compressed fuel-air mixture

Engines characterised by other types of ignition (characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition F02B 11/00; characterised by precombustion chambers F02B 19/00; characterised by air-storage chambers F02B 21/00; characterised by special shape or construction of combustion chambers F02B 23/00)
Definition statement

This place covers:

Engines characterised by other types of ignition.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Engines characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition

F02B 11/00

Engines characterised by precombustion chambers

F02B 19/00

Engines characterised by air-storage chambers

F02B 21/00

Engines characterised by special shape or construction of combustion chambers

F02B 23/00

with incandescent chambers
Special rules of classification

Illustrative example of subject matter classified in F02B 9/08

E.g. "Hot bulb" engines

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Engines characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition, e.g. in different cylinders (characterised by recombustion chambers F02B 19/00; characterised by air-storage chambers F02B 21/00; characterised by special shape or construction of combustion chambers F02B 23/00)
Definition statement

This place covers:

Engines characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition, e.g. in different cylinders. E.g.: engines switching between positive ignition and compression ignition, or performing homogeneous charge

compression ignition combustion during a first operating condition, and performing spark ignition or "diesel" combustion during a second operating condition.

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Engines characterised by precombustion chambers

F02B 19/00

Engines characterised by air-storage chambers

F02B 21/00

Engines characterised by special shape or construction of combustion chambers

F02B 23/00

Engines characterised by the introduction of liquid fuel into cylinders by use of auxiliary fluid
Definition statement

This place covers:

Engines characterised by the introduction of liquid fuel into cylinders by use of auxiliary fluid.

E.g. using compressed air or gas for blowing fuel into combustion chamber.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Fuel injection apparatuses where fuel-injection is effected by means of high-pressure gas

F02M 67/00

Engines characterised by the method of introducing liquid fuel into cylinders and not otherwise provided for
Definition statement

This place covers:

This group is only used for exceptional cases of engines with fuel introduction into cylinder that cannot be classified elsewhere.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Direct injection

F02B 2075/125

Indirect injection

F02M

Engines characterised by means for effecting stratification of charge in cylinders
Definition statement

This place covers:

Engines characterized by means for effecting stratification of charge in cylinders.

In a stratified charge engine, the fuel is injected into the cylinder just before ignition. This allows for higher compression ratios without "knock," and leaner air/fuel mixtures than in conventional internal combustion engines.

Relationships with other classification places

The stratification of the charge of air and fuel in the cylinder is determined by:

the shape of the air intake, the position of the fuel injector, the shape of the cylinder head, the shape of the piston head or combustion space.

References
Limiting references

This place does not cover:

Engines with air compression and subsequent fuel addition

F02B 3/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Combustion chambers (shape)

F02B 23/00

Modifying induction systems for imparting a rotation to the charge in the cylinder

F02B 31/00

Electrical control of supply of combustible mixture or its constituents

F02D 41/00

Cylinder heads (shape)

F02F 1/00

Pistons

F02F 3/00

Special rules of classification

Classification should be limited to the constructional features of the combustion chamber for making stratification of charge possible.

Control features are classified in F02D

F02B 17/005: having direct injection in the combustion chamber

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Stratification

Layers of air and fuel

Charge

Air and/or fuel contents in cylinder

Engines characterised by precombustion chambers (engines with incandescent chambers F02B 9/08)
Definition statement

This place covers:

Engines characterized by pre-combustion chambers.

Chambers are located at the cylinder head and connected to the engine cylinder by small holes. Generally the following steps in the combustion take place. During the compression stroke, air from the main cylinder enters the pre-combustion chamber. At this moment, fuel is injected into the pre-combustion chamber and is ignited by a spark plug or a glow plug. Pressure increases and the ignited charge is forced through the small holes into the main cylinder, resulting in an ignition of the main charge in the combustion chamber.

Relationships with other classification places

Indirect injection diesel engine. Multi fuel engines. Lean burn engines. Gas engines.

References
Limiting references

This place does not cover:

Engines with incandescent chambers

F02B 9/08

Engines with air storage cambers

F02B 21/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Engines with fuel air mixture compression

F02B 1/00

Engines with special shape of combustion chamber

F02B 23/00

Cylinders; Cylinder heads

F02F 1/00

Sparking plugs in partly enclosed ignition chamber

H01T 13/54

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Incandescent chamber

Chamber with hot spot

Torch passage

Passage between pre- and main combustion chamber

Squish area

Compressed area between piston top and cylinder head

Air swirl

Rotational movement of air

Synonyms and Keywords

In patent documents, the following words/expressions are often used as synonyms:

  • "pre-combustion chamber", "pre-chamber" and "ignition chamber"
Engines characterised by air-storage chambers
Definition statement

This place covers:

Engines with an auxiliary chamber which is connected and disconnected with the engine intake or cylinder during the compression or expansion period of the engine cycle in order to influence the compression or expansion process.

Relationships with other classification places

Provision for charging and scavenging, F02B 29/00. Pumps for air charging and scavenging, F02B 33/00. Using engine as a brake, F02D 13/00.

References
Limiting references

This place does not cover:

Air hybrid prime movers

B60K 6/08

Compressed air driven engines

F01B 29/08

Informative references

Attention is drawn to the following places, which may be of interest for search:

Cylinders; cylinder heads

F02F 1/00

Special rules of classification

F02B 21/02: Chamber shapes or constructions

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Auxiliary chamber

Chamber not being a combustion chamber

Synonyms and Keywords

In patent documents, the following words/expressions are often used as synonyms:

  • "air storage chamber" and "air accumulator "
  • "auxiliary chamber" and "air tank"
Other engines characterised by special shape or construction of combustion chambers to improve operation (engines with incandescent chambers F02B 9/08)
Definition statement

This place covers:

Engines characterised by a special shape of the combustion chamber to improve operation. The shape of the combustion space between the cylinder head and the working piston determines how the combustible mixture of air and fuel is combusted. The group mainly deals with the configuration of the combustion space in the piston for compression but also for spark ignited engines.

Relationships with other classification places

Configuration of cylinder heads and pistons, F02F 1/00. Position of fuel injectors, F02B 23/10 and air intake systems, F02B 31/00.

References
Limiting references

This place does not cover:

Engines with incandescent chambers

F02B 9/08

Cylinders

F02F 1/00

Pistons

F02F 3/00

Fuel injectors

F02M 39/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Air Induction systems

F02B 31/00

Cylinders

F02F 1/00

Pistons

F02F 3/00

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Squish flow

Flow through a narrowing area

Swirl flow

Flow in a circular current

Engines characterised by using fresh charge for scavenging cylinders (aspects characterised by provision of driven charging or scavenging pumps F02B 33/00 - F02B 39/00)
Definition statement

This place covers:

Engines characterized by using fresh charge for scavenging cylinders.

Mostly two-stroke engines i.e. internal combustion engines that complete the process cycle in one revolution of the crankshaft, i.e. an up stroke and a down stroke of the piston. This is accomplished by using the beginning of the compression stroke and the end of the combustion stroke to perform simultaneously the intake and exhaust or scavenging functions. In this way, two-stroke engines often provide high specific power, at least in a narrow range of rotational speeds. The functions of some or all of the valves required by a four-stroke engine are usually served in a two-stroke engine by ports that are opened and closed by the motion of the piston.

Relationships with other classification places

Gasoline, spark ignition versions are particularly useful in lightweight portable applications, such as lawn mowers. The concept is also used in diesel compression ignition engines in large applications, such as ships and locomotives.

References
Limiting references

This place does not cover:

Aspects characterized by provision of driven charging or scavenging pumps.

F02B 33/00 - F02B 39/00

Rotary engines

F02B 57/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Pumps for charging or scavenging

F02B 33/00

Engines for driving hand-held tools

F02B 63/00

Other types of engines

F02B 75/00

Rotary valve arrangements

F01L 7/00

Cylinders; cylinder heads

F02F 1/00

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Unidirectional scavenging

Scavenging gas flows in one directionin the cylinder

Reverse-flow scavenging

Scavenging gas flows up and down again

Reed valve

Type of unidirectional valve

Use of kinetic or wave energy of charge in induction systems, or of combustion residues in exhaust systems, for improving quantity of charge or for increasing removal of combustion residues (aspects characterised by provision of driven charging or scavenging pumps F02B 33/00 - F02B 39/00, e.g. use of driven apparatus for immediate conversion of combustion gas pressure into pressure of fresh charge F02B 33/42)
Definition statement

This place covers:

Internal combustion engines with a variable configuration intake manifold or exhaust manifold technology. Variable configuration intake or exhaust manifold technology can vary the configuration of the intake or exhaust tract in order to optimise power and torque across the range of engine speed operation, as well as help provide better fuel efficiency. The effect is often achieved by having two separate intake ports, each controlled by a valve, that open two different manifolds - one with a short path that operates at full engine load, and another with a significantly longer path that operates at lower load.

Relationships with other classification places

Engines characterized by provisions for charging or scavenging not provided for in groups F02B 25/00,F02B 27/00, F02B 33/00 - F02B 39/00

References
Limiting references

This place does not cover:

Aspects characterized by provision of driven charging or scavenging pumps

F02B 33/00 - F02B 39/00

Use of driven apparatus for immediate conversion of combustion gas pressure into pressure of fresh charge

F02B 33/42

Informative references

Attention is drawn to the following places, which may be of interest for search:

Modifying induction systems

F02B 31/00

Exhaust silencing apparatus

F01N 1/00

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Resonance charging

Oscillating air column charging

Engines characterised by provision for charging or scavenging not provided for in groups F02B 25/00, F02B 27/00 or F02B 33/00 - F02B 39/00; Details thereof
Definition statement

This place covers:

Means to improve the engine's volumetric efficiency by increasing the air intake density. The pressure of ambient air drawn in is increased and the temperature is decreased before it enters into the engine cylinder. This results in a greater mass of air entering the cylinder on each intake stroke.

Relationships with other classification places

Usually pumps, F02B 33/00 or turbochargers, F02B 37/00 are used to improve the engine's volumetric efficiency by increasing the air intake density. The compressor draws in ambient air and compresses it before it enters into the intake manifold at increased pressure. This results in a greater mass of air entering the cylinders on each intake stroke. In combination with these chargers provision, like cooling, F02B 29/00 or resonance charging, F02B 27/00 can be foreseen to improve the efficiency of these machines.

References
Limiting references

This place does not cover:

Resonance charging

F02B 27/00

Pumps for charging or scavenging

F02B 33/00

Turbo charging

F02B 37/00

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Fluid dynamic features

For example: air storage tanks

After charging

Charging after turbo or super charging

Synonyms and Keywords

In patent documents, the following words/expressions are often used as synonyms:

  • " heat exchanger" and "cooler"
Modifying induction systems for imparting a rotation to the charge in the cylinder (structural features of induction systems F02M)
Definition statement

This place covers:

Modifications of the induction system of internal combustion engines to improve the mixing and distribution of air and fuel in the cylinder. The group covers modifications to the intake passages up until the intake port of the cylinder of the engine.

Relationships with other classification places

A specific geometry of the induction system can create a beneficial air swirl or tumble pattern in the combustion chamber. The swirl or tumble helps to distribute the fuel and form a homogeneous air-fuel mixture. This aids the initiation of the combustion process.

References
Limiting references

This place does not cover:

Shape of combustion chamber

F02B 23/00

Lift valves

F01L 3/00

Cylinders, cylinder heads

F02F 1/00

Air induction systems

F02M 35/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Air induction systems

F02M 35/00

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Swirl

Rotation around cylinder axis

Tumble

Rotation around transverse cylinder axis

Synonyms and Keywords

In patent documents, the following words/expressions are often used as synonyms:

  • "swirl" and "turbulence"
Engines characterised by provision of pumps for charging or scavenging (characterised by the introduction of liquid fuel into cylinders by use of auxiliary fluid F02B 13/00; characterised by after-charging F02B 29/06; characterised by provision of pumps for sucking combustion residues from cylinders F02B 35/00; characterised by provision of exhaust-driven pumps F02B 37/00)
Definition statement

This place covers:

Engines characterised by provision of pumps for charging or scavenging.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Engines characterised by introducing fuel into cylinders by auxiliary fluid, e.g. by air-pressure

F02B 13/00

After-charging

F02B 29/06

Engines with pumps for sucking combustion residues from cylinders

F02B 35/00

Exhaust-driven pumps

F02B 37/00

Arrangements of such pumps or other auxiliary apparatus on engines

F02B 67/00

Turbochargers per se

F02C

Combined engine and pump control, control dependent on variables other than those generic to pumps

F02D

Pumps per se

F04

with simple crankcase pumps, i.e. with the rear face of a non-stepped working piston acting as sole pumping member in co-operation with the crankcase
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Cylinders characterised by having ports in cylinder for scavenging or charging

F02F 1/22

Special rules of classification

Illustrative example of subject matter classified in F02B 33/04

E.g.:

media5.jpg

with reciprocating-piston pumps other than simple crankcase pumps
Definition statement

This place covers:

With reciprocating-piston pumps other than simple crankcase pumps, e.g. engine-driven piston pumps.

with the working-cylinder head arranged between working and pumping cylinders
Special rules of classification

Illustrative example of subject matter classified in F02B 33/08

E.g.:

media6.jpg

the rear face of working piston acting as pumping member and co-operating with a pumping chamber isolated from crankcase, the connecting-rod passing through the chamber and co-operating with movable isolating member
Special rules of classification

Illustrative example of subject matter classified in F02B 33/12

E.g.:

media7.jpg

working and pumping pistons forming stepped piston
Special rules of classification

Illustrative example of subject matter classified in F02B 33/14

media8.jpg

with crankshaft being arranged between working and pumping cylinders
Special rules of classification

Illustrative example of subject matter classified in F02B 33/18

media9.jpg

with pumping-cylinder axis arranged at an angle to working-cylinder axis, e.g. at an angle of 90 degrees
Special rules of classification

Illustrative example of subject matter classified in F02B 33/20

E.g.:

media10.jpg

with pumping cylinder situated at side of working cylinder, e.g. the cylinders being parallel
Special rules of classification

Illustrative example of subject matter classified in F02B 33/22

E.g.:

media11.jpg

Four-stroke engines characterised by having crankcase pumps
Special rules of classification

Illustrative example of subject matter classified in F02B 33/26

E.g.:

media12.jpg

Control of inlet or outlet ports (controlling only working-cylinder inlets F01L)
Special rules of classification

Illustrative example of subject matter classified in F02B 33/30

E.g.:

media13.jpg

Engines with pumps other than of reciprocating-piston type (with crankcase pumps F02B 33/02)
References
Limiting references

This place does not cover:

Engines with crankcase pumps

F02B 33/02

with rotary pumps (with cell-type pressure exchangers or the like F02B 33/42)
References
Limiting references

This place does not cover:

Cell-type pressure exchangers or the like

F02B 33/42

of Roots type
Special rules of classification

Illustrative example of subject matter classified in F02B 33/38

E.g.:

media14.jpg

of non-positive-displacement type
Special rules of classification

Illustrative example of subject matter classified in F02B 33/40

E.g.:

media15.jpg

with driven apparatus for immediate conversion of combustion gas pressure into pressure of fresh charge, e.g. with cell-type pressure exchangers (pressure exchangers per se F04F 13/00)
Definition statement

This place covers:

Engine with driven or non-driven apparatus for immediate conversion of combustion gas pressure into pressure of fresh charge, e.g. with cell-type pressure exchangers.

E.g.:

media16.jpg

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Pressure exchangers per se

F04F 13/00

Passages conducting the charge from the pump to the engine inlet, e.g. reservoirs (cooling of charge after leaving pumps F02B 29/04)
Definition statement

This place covers:

Passages conducting the charge from the pump to the engine inlet, e.g. reservoirs. This group covers also air passages of turbocharged engines and scavenging channels with special features in two-stroke engines.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Cooling of charge after leaving the pump

F02B 29/04

Engines characterised by provision of pumps for sucking combustion residues from cylinders
Definition statement

This place covers:

Engines characterised by provision of pumps for sucking combustion residues from cylinders.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

After-charging

F02B 29/06

Arrangements of such pumps or other auxiliary apparatus on engines

F02B 67/00

using rotary pumps
Special rules of classification

Illustrative example of subject matter classified in F02B 35/02

e.g.:

media17.jpg

Engines characterised by provision of pumps driven at least for part of the time by exhaust (characterised by the introduction of liquid fuel into cylinders by use of auxiliary fluid F02B 13/00; characterised by after-charging F02B 29/06; characterised by passages conducting the charge from the pump to the engine inlet F02B 33/44)
Definition statement

This place covers:

Engines with turbocharging.

References
Limiting references

This place does not cover:

Engines characterised by provision of driven charging or scavenging pumps. Introducing fuel into cylinders by air-pressure

F02B 13/00

After-charging

F02B 29/06

Informative references

Attention is drawn to the following places, which may be of interest for search:

Passages conducting the charge from the pumps to the engine inlet

F02B 33/44

Turbo-compound

F02B 41/10

Arrangements of such pumps or other auxiliary apparatus on engines

F02B 67/00

Details or constructional aspects of non-positive displacement machines or engines, e.g. turbines,

F01D

Final actuators for bypassing part of the fluid in non-positive displacement machines or engines

F01D 17/105

Turbocharger casings, arrangement of bearings in turbochargers, cooling or lubrication of turbochargers per se

F01D 25/00

Turbochargers per se

F02C

Combined engine and pump control, control dependent on variables other than those generic to pump

F02D

Constructional aspects of pumps

F04C

Controls of pumps

F04D 15/00

Valves in general

F16K

with exhaust-driven pumps arranged in parallel {, e.g. at least one pump supplying alternatively}
Definition statement

This place covers:

with exhaust-driven pumps arranged in parallel. E.g. at least one parallel pump being driven alternatively.

media18.jpg

with exhaust-driven pumps arranged in series
Special rules of classification

Illustrative example of subject matter classified in F02B 37/013

E.g.:

media19.jpg

Engines with exhaust drive and other drive of pumps, e.g. with exhaust-driven pump and mechanically-driven second pump
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

The specific drive of the other drive

F02B 39/02

Control of the pumps
Definition statement

This place covers:

Control of turbocharging of engines. These groups cover also electronic control of turbochargers.

References
Limiting references

This place does not cover:

Details or constructional aspects of turbines

F01D

Constructional details of devices for control of turbochargers

F01D, F02C

Turbochargers

F02C

Combined engine and pump control, control dependent on variables other than those generic to pump

F02D

Controlling supercharged engines

F02D 23/00

Pumps

F04

{Control} of the alternation between {or the operation of} exhaust drive and other drive of a pump, e.g. dependent on speed
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Drives of a pump

F02B 39/02

by bypassing charging air
Definition statement

This place covers:

Illustrative example of subject matter classified in F02B 37/16

media20.jpg

{by bypassing, e.g. partially, intake air from pump inlet to pump outlet}
Definition statement

This place covers:

Control of pumps by bypassing air from the pump inlet to the pump outlet.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Valves for admission of atmospheric air to engine

F02B 33/446

{into the exhaust conduit (F02B 37/166 takes precedence)}
Definition statement

This place covers:

Control of pumps by bypassing charging air into the exhaust conduit.

References
Limiting references

This place does not cover:

The bypassed air being used in a combustion chamber

F02B 37/166

by bypassing exhaust {from the inlet to the outlet of turbine or to the atmosphere}
Definition statement

This place covers:

Controlling the pump by bypassing exhaust.

References
Limiting references

This place does not cover:

Constructional aspects of bypass valves

F01D 17/105

Informative references

Attention is drawn to the following places, which may be of interest for search:

Valves in general

F16K

{Arrangements of bypass valves or actuators therefor}
References
Limiting references

This place does not cover:

Constructional aspects of bypass valves

F01D 17/105

Informative references

Attention is drawn to the following places, which may be of interest for search:

Valves in general

F16K

Actuating devices in general

F16K 31/00

{Arrangements of actuators or linkage for bypass valves}
Definition statement

This place covers:

arrangement of actuators and linkage for bypass valves.

References
Limiting references

This place does not cover:

Actuating devices per se

F16K 31/00

by increasing exhaust energy, e.g. using combustion chamber {by after-burning (using an auxiliary combustion chamber supplied by charging air F02B 37/166)}
Definition statement

This place covers:

by increasing exhaust energy, e.g. using combustion chamber upstream of turbine or injecting water.

References
Limiting references

This place does not cover:

Using an auxiliary combustion chamber supplied by charging air

F02B 37/166

by varying cross-section of exhaust passages or air passages, {e.g. by throttling turbine inlets or outlets or by varying effective number of guide conduits (F02B 37/24 takes precedence)}
Definition statement

This place covers:

by varying cross-section of exhaust passages or air passages, e.g. by throttling turbine inlets or outlets or by varying effective number of guide conduits.

References
Limiting references

This place does not cover:

By using pumps or turbines with adjustable guide vanes

F02B 37/24

Constructional aspects per se of such devices

F02C, F01D 17/14

{air passages}
References
Limiting references

This place does not cover:

Constructional aspects per se of such devices

F02C, F01D

by using pumps or turbines with adjustable guide vanes
References
Limiting references

This place does not cover:

Constructional aspects per se of such devices

F01D 17/16, F02C

Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B 33/00 - F02B 37/00
Definition statement

This place covers:

Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B 33/00 - F02B 37/00.

References
Limiting references

This place does not cover:

Engines characterised by provision of driven charging or scavenging pumps. Introducing fuel into cylinders by air-pressure

F02B 13/00

After-charging

F02B 29/06

Arrangements of such pumps or other auxiliary apparatus on engines

F02B 67/00

Details or constructional aspects of turbines

F01D

Turbochargers

F02C

Plants in which engines use combustion products

F02C, F02G

Internal-combustion turbines

F02C

Combined engine and pump control, control dependent on variables other than those generic to pump

F02D

Pumps

F04

Pumps in general

F04

Machine element per se

F16

{Cooling of pump drives}
Definition statement

This place covers:

Arrangement of cooling system of super/turbocharger, layout (or partial layout) of cooling fluid circuits.

See e.g.:

media21.jpg

(from ep160243)

References
Limiting references

This place does not cover:

Turbocharger cooling per se, e.g. cooling a turbocharger bearing per se

F01D, F01D 25/125, F02C 6/12,

Cooling of turbochargers

F01D 25/12

Cooling of turbocharger bearings

F01D 25/125

Cooling of turbocharger casing

F01D 25/14

Cooling of machines or engines in general; cooling of internal-combustion engines

F01P

Drives of pumps (exhaust drives or combined exhaust and other drives F02B 37/00); Varying pump drive gear ratio (control acting both on engine and on pump drive gear ratio F02D)
References
Limiting references

This place does not cover:

Control acting both on engine and on pump drive gear ratio

F02D

Informative references

Attention is drawn to the following places, which may be of interest for search:

Exhaust drives or combined exhaust and other drives

F02B 37/00

Mechanical drives; Variable-gear-ratio drives (non-mechanical pump drives having variable gear ratio F02B 39/08)
References
Limiting references

This place does not cover:

Non-mechanical pump drives having variable gear ratio

F02B 39/08

Drives characterised by use of couplings or clutches therein (using fluid slip couplings for varying gear ratio F02B 39/08)
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Using fluid slip couplings for varying gear ratio

F02B 39/08

Lubrication of pumps; Safety measures therefor
Definition statement

This place covers:

Lubrication of pumps; Safety measures therefore, e.g. arrangement of lubrication system of super/turbocharger, layout (or partial layout) of lubrication fluid circuits.

References
Limiting references

This place does not cover:

Lubricating of machines or engines in general; lubricating internal-combustion engines

F01M

Turbocharger lubrication per se, e.g. lubricating a turbocharger bearing per se

F02C 6/12; F01D 25/18

Lubrication of bearings in general

F16C

Lubricating in general

F16N

Other safety measures for, or other control of, pumps
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Cleaning of turbomachines

F01D 25/002

Cleaning of pumps using liquids

F04D 29/705

Measuring vibration of turbo machines

G01H 1/006

Engines characterised by special means for improving conversion of heat or pressure energy into mechanical power
Definition statement

This place covers:

Engines characterised by special means for improving conversion of heat or pressure energy into mechanical power, e.g. modification of compression ratio to enhance thermal efficiency or by using "turbocompound" i.e. using the exhaust to drive a turbine connected to the crankshaft.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Variable compression ratio

F02B 75/04

Thermal insulation

F02B 77/11, F02B 77/02

Modified dwell of piston in TDC

F02B 2275/36

Engines with prolonged expansion
Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Prolonged expansion

relative to the compression

Modified dwell

The piston remains longer than usual at TOP DEAD CENTRE

Miller cycle

A modified four stroke cycle where the compression stroke is made shorter by blow back through late inlet valve closing, for turbo charged engines

Atkinson cycle

the same as Miller cycle, but for normally aspirated engines

in main cylinders
Definition statement

This place covers:

Engines with means and ways to make the compression stroke and the expansion stroke different.

E.g. engines using the Miller or Atkins cycles or using mechanical means in order to have special stroke of piston.

media22.jpg

in compound cylinders
Definition statement

This place covers:

Engines with more than one expansion stroke. I.e. the exhaust is allowed to expand in an additional cylinder. The compounding is similar to the compounding in a steam engine.

media23.jpg

Two-stroke compound engines
Definition statement

This place covers:

Two stroke engines with second expansion in an expansion cylinder

media24.jpg

in exhaust turbines (use of exhaust turbines for charging F02B 37/00; turbines constructions F01D; gas turbine plant F02C)
Definition statement

This place covers:

Turbocompounding. The exhaust gas is expanded in a turbine which is directly or indirectly connected to the engine crankshaft.

E.g.:

media25.jpg

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Turbine construction

F01D

Gas turbine plants

F02C

Use of exhaust turbines for charging

F02M 37/00

Engines characterised by operating on gaseous fuels; Plants including such engines (engines characterised by the gas-air charge being ignited by compression ignition of an additional fuel F02B 7/06; engines convertible from gas to other fuel consumption F02B 69/04)
Definition statement

This place covers:

Engines characterised by operating on gaseous fuels; Plants including such engines

media26.jpg

References
Limiting references

This place does not cover:

Engines characterised by the gas-air charge being ignited by compression ignition of an additional fuel

F02B 7/06

Engines convertible from gas to other fuel consumption

F02B 69/04

Control of gas supply per se

F02D 19/00

Installations for supply of gas per se

F02M 21/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Control of gas engines

F02D 19/00

Fuel supply apparatuses

F02M 21/00

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

LNG

Liquefied Natural Gas; behaves like an inert gas. It has a high critical compression ratio. Therefore, only used with spark ignition or pilot fuel ignition

LPG

Liquefied Petroleum Gas

CNG

Compressed Natural Gas

DME

Dimethyl ether

Engines or plants characterised by use of other specific gases, e.g. acetylene, oxyhydrogen
Definition statement

This place covers:

Engines of plants characterised by use of other specific gases, e.g. acetylene, oxyhydrogen, hydrogen, oxygen.

References
Limiting references

This place does not cover:

Production of hydrogen

C01B 3/02

Fuel cell per se

H01M 8/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Supplying engines with gaseous fuel

F02M 21/02

Methods of operating
Definition statement

This place covers:

methods of operating such engines.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Controlling combustion engines

F02D

Engines characterised by operating on non-liquid fuels other than gas; Plants including such engines (plants involving generation of gaseous fuel from solid fuel F02B 43/08; engines convertible from gas to other fuel consumption F02B 69/04)
Definition statement

This place covers:

Engines operating on non-liquid fuels other than gas, such as solid or semi-solid fuels.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Plants involving generation of gaseous fuels from solid fuel

F02B 43/08

Engines convertible from gas to other fuel consumption

F02B 69/04

operating on powdered fuel, e.g. powdered coal (operating on fuel containing oxidant F02B 45/06)
Definition statement

This place covers:

operating of powdered fuel e.g. powdered coal

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Operating on fuel containing oxidant

F02B 45/06

Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines
Definition statement

This place covers:

Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines:

media27.jpg

the substances being water or steam
References
Limiting references

This place does not cover:

Apparatus for adding water or steam to engine

F02M 25/00

the substances including non-airborne oxygen (F02B 47/10 takes precedence)
Definition statement

This place covers:

The added substance including non-airborne oxygen, e.g. N2O: Laughing gas

media28.jpg

References
Limiting references

This place does not cover:

Circulation of exhaust gas in closed or semi-closed circuits

F02B 47/10

Apparatus for supplying non-airborne oxygen to engine

F02M 25/10

the substances including exhaust gas
References
Limiting references

This place does not cover:

Apparatus for adding exhaust gas to engines

F02M 26/00

Circulation of exhaust gas in closed or semi-closed circuits, e.g. with simultaneous addition of oxygen
References
Limiting references

This place does not cover:

Apparatus for adding exhaust gas to engine

F02M 26/00

Methods of operating air-compressing compression-ignition engines involving introduction of small quantities of fuel in the form of a fine mist into the air in the engine's intake
Definition statement

This place covers:

Methods of operating air-compressing compression-ignition engines involving introduction of small quantities of fuel in the form of a fine mist into the air in the engine's intake. E.g. as starting aid

media29.jpg

Other methods of operating engines involving pretreating of, or adding substances to, combustion air, fuel, or fuel-air mixture of the engines
Definition statement

This place covers:

Other methods of operating engines involving pretreating of, or adding substances to, combustion air, fuel, or fuel-air mixture of the engines.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Apparatuses for treating combustion-air, fuel of fuel-air mixture, by catalyst, electric means, magnetism, rays, sound waves or the like

F02M 27/00

involving catalysts
References
Limiting references

This place does not cover:

Apparatus for treating combustion-air, fuel, or fuel-air mixture by catalyst

F02M 27/02

involving electricity or magnetism
References
Limiting references

This place does not cover:

Apparatus for treating combustion-air, fuel, or fuel-air mixture by electric means or magnetism

F02M 27/04

involving rays or sound waves
References
Limiting references

This place does not cover:

Apparatus for treating combustion-air, fuel, or fuel-air mixture by sonic or ultrasonic waves

F02M 27/08

Internal-combustion aspects of rotary-piston or oscillating-piston engines (internal-combustion aspects of rotary pistons or outer members for co-operation therewith F02B 55/00)
Definition statement

This place covers:

Internal-combustion aspects of rotary-piston or oscillating-piston engines

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Internal combustion aspects of rotary pistons or outer members of co-operating therewith

F02B 55/00

Rotary-piston machines or engines per se

F01C 1/00, F01C 3/00, F01C 5/00, F01C 7/00

Oscillating-piston machines or engines

F01C 9/00

Internal-combustion aspects of rotary pistons; Outer members for co-operation with rotary pistons
Definition statement

This place covers:

Internal combustion aspects of rotary pistons or outer members for co-operation with rotary pistons.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Rotary-piston machines or engines per se

F01C 1/00, F01C 3/00, F01C 5/00, F01C 7/00

Oscillating-piston machines or engines

F01C 9/00

Cooling thereof
Special rules of classification

Illustrative example of subject matter classified in F02B 55/10

E.g.:

media30.jpg

Internal-combustion aspects of rotary engines in which the combusted gases displace one or more reciprocating pistons
Definition statement

This place covers:

Internal-combustion aspects of rotary engines in which the combusted gases displace one or more reciprocating pistons. E.g.:

media31.jpg

Fuel or combustion-air supply (cylinder-charge admission or exhaust control F02B 57/04)
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Cylinder-charge admission of exhaust control

F02B 57/04

Control of cylinder-charge admission or exhaust (peculiar to two-stroke engines or to other engines with working-piston-controlled charge admission or exhaust F02B 57/06)
References
Limiting references

This place does not cover:

Two-stroke engines or other engines with working-piston-controlled charge admission or exhaust

F02B 57/06

Two-stroke engines or other engines with working-piston-controlled cylinder-charge admission or exhaust (with combustion space in centre of star F02B 57/10)
References
Limiting references

This place does not cover:

With combustion space in centre of star

F02B 57/10

Engines with star-shaped cylinder arrangements
Definition statement

This place covers:

Engines with star-shaped cylinder arrangements, e.g.

media32.jpg

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Reciprocating-piston machines or engines with the rotating cylinders arranged substantially tangentially to a circle centred on the main shaft axis

F01B 13/045

Reciprocating-piston machines or engines with rotating cylinders in star arrangement

F01B 13/06

with combustion space in centre of star
Definition statement

This place covers:

Engines with combustion space in centre of star, e.g.:

media33.jpg

Internal-combustion aspects of other reciprocating-piston engines with movable, e.g. oscillating, cylinders (with yieldable walls F02B 75/38)
Definition statement

This place covers:

Internal-combustion aspects of other reciprocating-piston engines with movable, e.g. oscillating, cylinders. E.g.:

media34.jpg

References
Limiting references

This place does not cover:

Reciprocating-piston engines with parts of combustion- or working-chamber walls resiliently yielding under pressure

F02B 75/38

Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing (the engine torque being divided by a differential gear for driving a scavenging or charging pump and the engine output shaft F02B 39/06; adaptations or combinations of rotary-piston or oscillating-piston engines F02B 53/14; arrangements in vehicles, see the relevant classes for vehicles)
Definition statement

This place covers:

Adaptations of engines for driving vehicles of for driving propellers; Combinations of engines with gearing.

media35.jpg

References
Limiting references

This place does not cover:

Engine torque being divided by a differential gear for driving a scavenging or charging pump and the engine output shaft

F02B 39/06

Adaptions of combinations of rotay-piston or oscillating-piston engines

F02B 53/14

Arrangement in vehicles

see the relevant classes for the specific vehicles

for driving cycles
Definition statement

This place covers:

Engines for driving cycles; E.g.:

media36.jpg

for driving propellers
Definition statement

This place covers:

Engines for driving propellers; E.g.:

media37.jpg

{for outboard marine engines}
Definition statement

This place covers:

Outboard marine and engines, Inboard marine engines, Jetski engines.

media38.jpg

Combinations of engines with mechanical gearing (F02B 61/02, F02B 61/04 take precedence)
Definition statement

This place covers:

Combinations of engines with mechanical gearing

media39.jpg

References
Limiting references

This place does not cover:

Adaptations of engines for driving cycles

F02B 61/02

Adaptations of engines for driving propellers

F02B 61/04

Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices (of rotary-piston or oscillating-piston engines F02B 53/14)
Definition statement

This place covers:

Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices

References
Limiting references

This place does not cover:

Adaptations of rotary-piston or oscillating-piston engines

F02B 53/14

for electric generators
Definition statement

This place covers:

Adaptations of engines for electric generators; E.g.:

media40.jpg

Adaptations of engines for special uses not provided for in groups F02B 61/00 or F02B 63/00; Combinations of engines with other devices, e.g. with non-driven apparatus (of rotary-piston or oscillating-piston engines F02B 53/14; combinations of prime-movers consisting of electric motors and internal combustion engines for mutual or common propulsion B60K 6/20)
Definition statement

This place covers:

Adaptations of engines for special uses not provided for in groups F02B 61/00 or F02B 63/00; Combinations of engines with other devices, e.g. with non-driven apparatus. E.g. Internal combustion engine where an engine cylinder may act as an air compressor

References
Limiting references

This place does not cover:

Adaptations of rotary-piston or oscillating-piston engines

F02B 53/14

Combinations of prime-movers consisting of electric motors and internal combustion engines for mutual or common propulsion

B60K 6/20

Engines characterised by the arrangement of auxiliary apparatus not being otherwise provided for, e.g. the apparatus having different functions; Driving auxiliary apparatus from engines, not otherwise provided for
Definition statement

This place covers:

Engines characterised by the arrangement of auxiliary apparatuses not being otherwise provided for, e.g. the apparatus having different functions; Driving auxiliary apparatus from engines, not otherwise provided for.

driven by means of chains, belts, or like endless members
Definition statement

This place covers:

Auxiliary devices driven by means of chains, belts, or like endless members

media41.jpg

of non-mechanically driven auxiliary apparatus
Definition statement

This place covers:

Non-mechanically driven auxiliary apparatus. E.g. electrically, hydraulically or pneumatically driven.

of charging or scavenging apparatus
Definition statement

This place covers:

Engines characterised by the arrangement charging or scavenging apparatus. E.g driving arrangement or mounting arrangement. Also for particular positioning with respect to engine.

media42.jpg

Internal-combustion engines convertible into other combustion-engine type, not provided for in F02B 11/00; Internal-combustion engines of different types characterised by constructions facilitating use of same main engine-parts in different types
Definition statement

This place covers:

Internal combustion engines convertible into other combustion-engine type not provided for in F02B 11/00; Internal-combustion engines of different types characterised by constructions facilitating use of same main engine-parts in different types.

E.g. engines convertible from two stroke to four stroke, or convertible for use with different fuels

References
Limiting references

This place does not cover:

Engines characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition, e.g. in different cylinders

F02B 13/00

Free-piston engines; Engines without rotary main shaft
Definition statement

This place covers:

Free-piston engines; Engines without rotary main shaft. E.g.:

media43.jpg

Combinations of two or more engines, not otherwise provided for
Definition statement

This place covers:

E.g. combining two or more engines, not otherwise provided for, e.g. of the same or different type, e.g. an internal combustion engine and a Stirling engine.

media44.jpg

Other engines
Definition statement

This place covers:

Other engines

{Double acting engines}
Definition statement

This place covers:

Double acting engines

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{having horizontal cylinders (F02B 75/007 takes precedence)}
Definition statement

This place covers:

Engines having horizontal cylinders. E.g.:

media46.jpg

References
Limiting references

This place does not cover:

Engines having vertical crankshafts

F02B 75/007

{having vertical crankshafts}
Definition statement

This place covers:

Engines having vertical crankshafts

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Engines characterised by their cycles, e.g. six-stroke
Definition statement

This place covers:

Engines characterised by their cycles, e.g. six-stroke.

Engines with variable distances between pistons at top dead-centre positions and cylinder heads
Definition statement

This place covers:

Engines with variable distances between pistons at top dead-centre positions and cylinder heads; E.g.:

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Valve operation

F01L

Controlling engines with variable distances between piston and cylinder head

F02D

{by means of cylinder or cylinderhead positioning}
Definition statement

This place covers:

Engines characterised by means of cylinder or cylinder head positioning; E.g.:

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{by means of an adjustable piston length}
Definition statement

This place covers:

Engines characterised by means of an adjustable piston length; E.g.:

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{by means of a variable connecting rod length}
Definition statement

This place covers:

Engines characterised by means of a variable connecting rod length; E.g.:

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{by means of variable crankshaft position}
Definition statement

This place covers:

Engines characterised by means of variable crankshaft position; E.g.:

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{by means of a variable crank stroke length}
Definition statement

This place covers:

Engines characterised by means of a variable crank stroke length; E.g.:

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Engines with means for equalising torque (compensations of inertial forces, suppression of vibration in systems F16F)
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Compensation of inertial forces, suppression of vibration in systems

F16F

{with double connecting rods or crankshafts}
Definition statement

This place covers:

Engines with double connecting rods or crankshafts; E.g.:

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Engines with means for preventing corrosion in gas-swept spaces
Definition statement

This place covers:

Engines with means for preventing corrosion in gas-swept spaces

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Running faces of engine cylinders; cylinder liners

F16J 10/04

Engines with means for rendering exhaust gases innocuous (apparatus per se F01N)
Definition statement

This place covers:

Engines with means for rendering exhaust gases innocuous.

References
Limiting references

This place does not cover:

Apparatus for purifying, rendering innocuous or otherwise treating exhaust

F01N 3/00

Control of combustion engines

F02D

{with two or more pistons connected to one crank and having a common combustion space}
Definition statement

This place covers:

Engines with two or more pistons connected to one crank and having a common combustion space; E.g.:

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with cylinders all in one line
Definition statement

This place covers:

Illustrative example of subject matter classified in this group:

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with cylinders in V, fan, or star arrangement
Definition statement

This place covers:

Engines with cylinders in V, fan, or star arrangement

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{with cylinder banks in narrow V-arrangement, having a single cylinder head}
Definition statement

This place covers:

Engines with cylinder banks in narrow V-arrangement, having a single cylinder head.

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{with cylinders in star arrangement}
Definition statement

This place covers:

Engines with cylinders in star arrangement; E.g.:

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{with cylinders in fan arrangement}
Definition statement

This place covers:

Engines with cylinders in fan arrangement

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{having two or more crankshafts}
Definition statement

This place covers:

Engines having two or more crankshafts

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{with cylinder banks in X-arrangement, e.g. double-V engines}
Definition statement

This place covers:

Engines with cylinder banks in X-arrangement, e.g. double-V engines

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{with cylinders arranged in parallel banks}
Definition statement

This place covers:

Engines with cylinders arranged in parallel banks

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{with only one crankshaft of the "boxer" type, e.g. all connecting rods attached to separate crankshaft bearings}
Definition statement

This place covers:

Engines with only one crankshaft of the "boxer" type, e.g. all connecting rods attached to separate crankshaft bearings

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{with only one crankshaft of the "pancake" type, e.g. pairs of connecting rods attached to common crankshaft bearing}
Definition statement

This place covers:

Engines with only one crankshaft of the "pancake" type, e.g. pairs of connecting rods attached to common crankshaft bearing

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Engines with cylinder axes coaxial with, or parallel or inclined to, main-shaft axis; Engines with cylinder axes arranged substantially tangentially to a circle centred on main-shaft axis
Definition statement

This place covers:

Engines with cylinder axes coaxial with, or parallel or inclined to, main-shaft axis; Engines with cylinder axes arranged substantially tangentially to a circle centered on main-shaft axis

media68.jpg

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis

F01B 3/00

{Engines with cylinder axes substantially tangentially to a circle centred on main-shaft axis}
Definition statement

This place covers:

Engines with cylinder axes substantially tangentially to a circle centred on main-shaft axis

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Engines with two or more pistons reciprocating within same cylinder or within essentially coaxial cylinders (arranged oppositely relative to main shaft F02B 75/24)
Definition statement

This place covers:

Engines with two or more pistons reciprocating within same cylinder or within essentially coaxial cylinders

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References
Limiting references

This place does not cover:

Multi-cylinder engines with cylinders arranged oppositely relative to main shaft

F02B 75/24

Informative references

Attention is drawn to the following places, which may be of interest for search:

Engines with with oppositely reciprocating pistons

F01B 7/02

{the pistons having equal strokes}
Definition statement

This place covers:

Engines with pistons having equal strokes

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{comprising a free auxiliary piston}
Definition statement

This place covers:

Engines comprising a free auxiliary piston

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{with several pistons positioned in one cylinder one behind the other}
Definition statement

This place covers:

Engines with several pistons positioned in one cylinder one behind the other

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with one working piston sliding inside another
Definition statement

This place covers:

Engines with one working piston sliding inside another

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Engines characterised by connections between pistons and main shafts and not specific to preceding main groups
Definition statement

This place covers:

This subgroup contains all mechanisms between pistons and main shafts not otherwise described in more pertinent classes.

This example is for an engine with pulled con-rods during working stroke.

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Details for the given mechanism connecting pistons and main shafts

F01B

Ultra-small engines, e.g. for driving models
Definition statement

This place covers:

Ultra-small engines, e.g. for driving models

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ANY "SMALL" ENGINE; MINIATURE CO2 ENGINES; COMPRESSED AIR ENGINES.

Cycles possible: DIESEL, GLOW IGN., SPARK ign.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Homogeneous Charge Compression Ignition

F02B 1/12

For steam or compressed air drive mechanism for toys

A63H 29/16

Compressed air engines

F01B 17/00

Synonyms and Keywords

In patent documents the following expressions/words "diesel", "glowplug", "c-methanol", "castor oil", " nitro methane" and "amylnitrate" are often used.

Engines with parts of combustion- or working-chamber walls resiliently yielding under pressure
Definition statement

This place covers:

Engines with parts of combustion- or working-chamber walls resiliently yielding under pressure

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Reciprocating - piston engines (F02B 75/04 takes precedence; with resiliently-urged auxiliary piston in pre-combustion chamber F02B 19/06)
Definition statement

This place covers:

Reciprocating piston engines. E.g.:

media79.jpg

References
Limiting references

This place does not cover:

Engines with resiliently-urged auxiliary piston in pre-combustion chamber

F02B 19/06

Engines with variable distances between pistons at top dead-centre positions and cylinder heads

F02B 75/04

Other reciprocating-piston engines
Definition statement

This place covers:

Other reciprocating-piston engines

E.g.:

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Component parts, details or accessories, not otherwise provided for
Definition statement

This place covers:

These groups covers component parts, details or accessories, not otherwise provided for. E.g. freeze plugs, thermal or acoustic insulation etc.

Surface coverings of combustion-gas-swept parts (of pistons or cylinders only F02F)
References
Limiting references

This place does not cover:

Surface coverings of pistons or cylinders only

F02F

Cleaning of, preventing corrosion or erosion in, or preventing unwanted deposits in, combustion engines {(cleaning of fuel injection apparatus F02M 65/00)}
Definition statement

This place covers:

Any cleaning of engines, decarbonising, de-coking.

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References
Limiting references

This place does not cover:

Cleaning of fuel injection apparatus

F02M 65/00

Safety, indicating or supervising devices (thermal insulation F02B 77/11; {rendering engines inoperative or idling F02D 17/04; dependent on lubricating conditions F01M 1/22; dependent on cooling F01P 11/14})
Definition statement

This place covers:

Indicating and warning devices.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Thermal insulation

F02B 77/11

Rendering engines inoperative or idling on lubricant pressure failure

F01M 1/22

Indicating or safety devices relating to cooling

F01P 11/14

Control of combustion engines

F02D

Rendering engines inoperative or idling

F02D 17/04

{relating to endless members (endless members, e.g. belts, for driving auxiliary apparatus F02B 67/04)}
Definition statement

This place covers:

Safety, indicating or supervising devices relating to endless members

media82.jpg

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Endless members, e.g. belts, for driving auxiliary apparatus

F02B 67/04

{relating to valves}
Definition statement

This place covers:

Safety, indicating or supervising devices relating to valves

media83.jpg

{relating to maintenance, e.g. diagnostic device (relating to lubrication F01M 11/10)}
Definition statement

This place covers:

Safety, indicating or supervising devices relating to maintenance, e.g. diagnostic device

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Indicating and safety devices concerning lubricant level

F01M 11/10

{indicating economy}
Definition statement

This place covers:

Safety, indicating or supervising devices indicating economy

media85.jpg

{with sensors measuring combustion processes, e.g. knocking, pressure, ionization, combustion flame}
Definition statement

This place covers:

Safety, indicating or supervising devices with sensors measuring combustion processes, e.g. knocking, pressure, ionization, combustion flame

media86.jpg

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Control of combustion engines

F02D

{Sensor arrangements in the exhaust, e.g. for temperature, misfire, air/fuel ratio, oxygen sensors}
Definition statement

This place covers:

Sensor arrangements in the exhaust, e.g. for temperature, misfire, air/fuel ratio, oxygen sensors

media87.jpg

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Using sensors in exhaust for controlling combustion engine

F02D 41/00

{determining top dead centre or ignition-timing}
Definition statement

This place covers:

Safety, indicating or supervising devices determining top dead centre or ignition-timing

media88.jpg

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Controlling combustion engines

F02D

{relating to tightness}
Definition statement

This place covers:

Safety, indicating or supervising devices relating to tightness

media89.jpg

{relating to engine temperature (concerning coolant temperature F01P 11/16)}
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Indicating and safety devices concerning coolant temperature

F01P 11/16

Safety means relating to crankcase explosions
Definition statement

This place covers:

Safety means relating to crankcase explosions

media90.png

Thermal or acoustic insulation
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Thermal insulation in general

F16L 59/00

Acoustic insulation
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Sound insulation of engine casings, e.g. crankcases

F02F 7/008

Engine-driven auxiliary devices combined into units
Definition statement

This place covers:

Engine-driven auxiliary devices combined into units: E.g. a water pump and an alternator combined in one unit.

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Running-in of internal-combustion engines (lubrication thereof F01M)
Definition statement

This place covers:

Running-in of internal-combustion engines.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Lubrication of internal combustion engines

F01M