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SUPPLYING COMBUSTION ENGINES IN GENERAL, WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF (charging such engines F02B)
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Carburettors
Apparatus for mixing fuel with air, the fuel being brought into mixing contact with the air by lowering the air pressure, e.g. in a venturi
Fuel-injection apparatus
Apparatus for introducing fuel into a space, e.g. engine cylinder, by pressurising the fuel, e.g. by a pump acting behind the fuel, and thus includes the so-called "solid-fuel injection" in which liquid fuel is introduced without any admixture of gas
Low-pressure fuel injection
Fuel injection in which the fuel-air mixture containing fuel thus injected will be substantially compressed in the compression stroke of the engine
Pumping element
A single piston-cylinder unit in a reciprocating-piston fuel-injection pump or the equivalent unit in any other type of fuel-injection pump
Carburettors with means for facilitating engine's starting or its idling below operational temperatures
Definition statement
This subclass/group covers:

When the engine is cold, fuel vaporizes less readily and tends to condense on the walls of the intake manifold, starving the cylinders of fuel and making the engine difficult to start; thus, a richer mixture is required to start and run the engine until it warms up. To provide the extra fuel, a choke is typically used; this is a device that restricts the flow of air at the entrance to the carburettor, before the venturi. With this restriction in place, extra vacuum is developed in the carburettor venturi, which pulls extra fuel through the main metering system to supplement the fuel being pulled from the idle and off-idle circuits. This provides the rich mixture required to sustain operation at low engine temperatures. In addition, the choke can be connected to a cam or other device which prevents the throttle plate from closing fully while the choke is in operation. This causes the engine to idle at a higher speed. Fast idle serves as a way to help the engine warm up quickly, and give a more stable idle while cold by increasing airflow throughout the intake system which helps to better atomize the cold fuel. In many carburetted cars, the choke is controlled by a cable connected to a pull-knob on the dashboard operated by the driver. In some carburetted cars it is automatically controlled by a thermostat employing a bimetallic spring, which is exposed to engine heat, or to an electric heating element. This heat may be transferred to the choke thermostat via simple convection, via engine coolant, or via air heated by the exhaust. Some carburettors do not have a choke but instead use a mixture enrichment circuit. Typically used on small engines, enricheners work by opening a secondary fuel circuit below the throttle valves. This circuit works exactly like the idle circuit, and when engaged it simply supplies extra fuel when the throttle is closed.

Relationship between large subject matter areas

Carburettors are used in all types of engines. Nowadays new inventions mainly take place in the field of small engines. e.g. motorcycles, lawn mowers.

References relevant to classification in this group
This subclass/group does not cover:
Carburettors for gaseous fuel
Carburettors combined with low pressure fuel injection
Informative references
Attention is drawn to the following places, which may be of interest for search:
Idling devices
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Idling
Engine running stationary
Priming
Pumping extra fuel
Float chamber
Fuel collection chamber controlled by float member
Idling devices (with means for facilitating idling below operational temperatures F02M 1/00)
Definition statement
This subclass/group covers:

Devices for delivering the correct amount of fuel and air under idling i.e. slow running conditions of the engine.

Relationship between large subject matter areas

Low-pressure fuel-injection apparatus, F02M 69/00.

References relevant to classification in this group
This subclass/group does not cover:

Carburettors with means for facilitating engine's starting or its idling below operational temperatures

Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions
Informative references
Attention is drawn to the following places, which may be of interest for search:

Apparatus for adding secondary air to fuel-air mixture

Float-controlled apparatus for maintaining a constant fuel level
Definition statement
This subclass/group covers:

To ensure a ready mixture, the carburettor has a float chamber that contains a quantity of fuel at near-atmospheric pressure, ready for use. This reservoir is constantly replenished with fuel supplied by a fuel pump. The correct fuel level in the bowl is maintained by means of a float controlling an inlet valve When fuel is used up, the float drops, opening the inlet valve and admitting fuel. As the fuel level rises, the float rises and closes the inlet valve. The level of fuel maintained in the float bowl can usually be adjusted by a setscrew.

Relationship between large subject matter areas

Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions, F02M 7/00.

References relevant to classification in this group
This subclass/group does not cover:
Floatless carburettors
Informative references
Attention is drawn to the following places, which may be of interest for search:

Details, component parts, or accessories of carburettors, not provided for in, or of interest apart from, the apparatus of groups F02M 1/00 to F02M 17/00

Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Float
Hollow body floating on fuel level and acting on fuel inlet valve
Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions (choke valves for starting F02M 1/00)
Definition statement
This subclass/group covers:

Under all engine operating conditions, the carburettor must measure the airflow of the engine, deliver the correct amount of fuel to keep the air/fuel mixture in the proper range and distribute the two finely and evenly. This job would be simple if air and gasoline were ideal fluids; in practice, however, their deviations from ideal behaviour due to viscosity, fluid drag, inertia, etc. require a great deal of complexity to compensate for exceptionally high or low engine speeds. A carburettor must provide the proper air/fuel mixture across a wide range of ambient temperatures, atmospheric pressures, engine speeds and loads and centrifugal forces, like cold start, hot start, idling, acceleration, high speed at full throttle (high load), slow speed at part throttle (light load).

To function correctly under all these conditions, carburettors contain a complex set of mechanisms to support several different operating modes.

Relationship between large subject matter areas

Electrical control of supply of combustible mixture or its constituents, F02D 41/00.

References relevant to classification in this group
This subclass/group does not cover:
Carburettors with means for facilitating engine's starting or its idling below operational temperatures
Idling devices
Informative references
Attention is drawn to the following places, which may be of interest for search:
Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Aerated fuel spray nozzles
Nozzle with air and fuel dispersion
Equaliser jets
Jets for equalising the air/fuel ratio
Carburettors having air or fuel-air mixture passage throttling valves other than of butterfly type (register-type carburettors F02M 11/00); Carburettors having fuel-air mixing chambers of variable shape or position
Definition statement
This subclass/group covers:

A carburettor basically consists of an open pipe through which the air passes into the inlet manifold of the engine. The pipe is in the form of a venture, which narrows in section and then widens again, causing the airflow to increase in speed in the narrowest part. Below the venturi is a valve called the throttle valve. This valve controls the flow of air through the carburettor throat and thus the quantity of air/fuel mixture the system will deliver, thereby regulating engine power and speed. The throttle valve is connected through a mechanical linkage of rods and joints to the accelerator pedal.

Relationship between large subject matter areas

Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits, F02D 9/00.

References relevant to classification in this group
This subclass/group does not cover:
Register-type carburettors
Informative references
Attention is drawn to the following places, which may be of interest for search:
Throttle valves having slidably mounted valve members
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Iris diaphragms
Series of metal plates that can fold in over an opening on each other
Synonyms and Keywords

In patent documents the following expressions " Carburettor throat" and "Carburettor venturi " are often used as synonyms.

Multi-stage carburettors, Register-type carburettors, i.e. with slidable or rotatable throttling valves in which a plurality of fuel nozzles, other than only an idling nozzle and a main one, are sequentially exposed to air stream by throttling valve
Definition statement
This subclass/group covers:

Carburettors with a plurality of means for adjusting the air to fuel mixing ratio according to the operational requirements, like acceleration, deceleration and idling of the engine.

Relationship between large subject matter areas

Electrical control of supply of combustible mixture or its constituents, F02D 41/00.

References relevant to classification in this group
This subclass/group does not cover:
Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions
Informative references
Attention is drawn to the following places, which may be of interest for search:
Arrangements of two or more separate carburettors
Carburettors using more than one fuel
Synonyms and Keywords

In patent documents the following expressions " Multi stage carburettor" and "Register carburettor" are often used as synonyms.

Arrangements of two or more separate carburettors (re-atomising condensed fuel or homogenising fuel-air mixture F02M 29/00); Carburettors using more than one fuel (apparatus for adding small quantities of secondary fuel F02M 25/00)
Definition statement
This subclass/group covers:

The arrangement of two or more carburettors on the intake conduits of internal combustion engines and related constructional features.

Relationship between large subject matter areas

Combustion air cleaners, air intakes, intake silencers or induction systems specially adapted for, or arranged on, internal combustion engines, F02M 35/00.

References relevant to classification in this group
This subclass/group does not cover:
Multi-stage carburettors
Apparatus for adding small quantities of secondary fuel
Re-atomising condensed fuel or homogenising fuel-air mixture
Informative references
Attention is drawn to the following places, which may be of interest for search:
Controlling engines by throttling air or fuel and air induction conduits or exhaust conduits.
Carburettors with heating, cooling, or thermal insulating means for combustion-air, fuel, or fuel-air mixture (heating, cooling, or thermally insulating float apparatus F02M 5/00; apparatus for thermally treating combustion-air, fuel, or fuel-air mixture not being part of a carburettor F02M 31/00)
Definition statement
This subclass/group covers:

Carburettors with means for preventing freezing or overheating of the carburettor.

Relationship between large subject matter areas

Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture, F02M 31/00.

References relevant to classification in this group
This subclass/group does not cover:
Carburettors with means for facilitating engine's starting or its idling below operational temperatures
Heating, cooling, or thermally insulating float apparatus
Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture not being part of a carburettor
Informative references
Attention is drawn to the following places, which may be of interest for search:
Carburettors having pertinent characteristics not provided for in, or of interest apart from, the apparatus of preceding main groups
Carburettors having pertinent characteristics not provided for in, or of interest apart from, the apparatus of preceding main groups (apparatus for treating combustion-air, fuel, or fuel-air mixture by catalysts, electric means, magnetism, rays, sound waves, or the like F02M 27/00; combinations of carburettors and low-pressure fuel-injection apparatus F02M 71/00)
Definition statement
This subclass/group covers:

Carburettors with a different type of configuration, like fuel bath carburettors or normal carburettors having special properties, like membrane carburettors.

Relationship between large subject matter areas

Low-pressure fuel-injection apparatus, F02M 69/00.

References relevant to classification in this group
This subclass/group does not cover:
Apparatus for treating combustion-air, fuel or fuel-air mixture by catalysts, electric means, magnetism, rays, sound waves or the like
Combinations of carburettors and low-pressure fuel-injection apparatus
Informative references
Attention is drawn to the following places, which may be of interest for search:
Combinations of carburettors and low-pressure fuel-injection apparatus.
Details, component parts, or accessories of carburettors, not provided for in, or of interest apart from, the apparatus of groups F02M 1/00 to F02M 17/00 (measuring or testing apparatus in general G01)
Definition statement
This subclass/group covers:

Details of carburettors, e.g. metering orifices, spray nozzles, venturis, external control gear.

Relationship between large subject matter areas

Low-pressure fuel-injection apparatus, F02M 69/00.

References relevant to classification in this group
This subclass/group does not cover:
Aspects from preceding groups
Measuring or testing apparatus in general
G01/00
Informative references
Attention is drawn to the following places, which may be of interest for search:
Carburettors having pertinent characteristics not provided for in, or of interest apart from, the apparatus of preceding main groups
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Dashpot
Type of damper
Synonyms and Keywords

In patent documents the following expressions "Carburettor throat" and "Carburettor venturi" are often used as synonyms.

Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
Definition statement
This subclass/group covers:

Systems like tanks, vaporizers, pumps and injectors for supplying engines with a non-liquid, mostly gaseous fuel. A gas engine differs from a petrol engine in many ways. The fuel and air are mixed differently. The combustion of a gas/ air mixture is different form a liquid fuel/ air mixture and requires adaptation of the combustion space. Also the energy contents of gas is much lower than that of a liquid fuel. Since (natural) gas is a clean, economical and readily available fuel, many industrial engines are either designed or modified to use gas, as distinguished from gasoline.

Relationship between large subject matter areas

Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures, F02D 19/00.

References relevant to classification in this group
This subclass/group does not cover:
Engines characterised by operating on gaseous fuels; plants including such engines
Informative references
Attention is drawn to the following places, which may be of interest for search:
Engines characterised by pre-combustion chambers
Carburettors adapted to use liquid and gaseous fuels
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Gaseous fuel
Fuel being a gas at atmospheric pressure and room temperature
Apparatus for adding secondary air to fuel-air mixture
Definition statement
This subclass/group covers:

Apparatus for adding secondary air to the air/fuel mixture for varying or keeping constant the air/fuel ratio under varying engine operating circumstances, like acceleration, deceleration, cold start and high torque.

Relationship between large subject matter areas

Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel, or fuel-air mixture, F02M 25/00.

References relevant to classification in this group

Engines characterised by air-storage chambers
Informative references
Attention is drawn to the following places, which may be of interest for search:
Carburettors with means for influencing, e.g. enriching or keeping constant fuel/air ratio of charge under varying conditions
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Secondary air
air not entering the engine via the main air intake
Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel, or fuel-air mixture (F02M 43/00 takes precedence; adding secondary air to fuel-air mixture F02M 23/00)
Definition statement
This subclass/group covers:

Apparatus for adding water, lubricant vapours, fuel vapours or exhaust gases to the combustion mixture. These substances are added to improve the combustion properties of the fuel/air mixture and/or make the exhaust gases cleaner or prevent harmful gases from escaping to atmosphere.

Relationship between large subject matter areas

Controlling engines characterised by their being supplied with non-airborne oxygen or other non-fuel gas, F02D 21/00.

References relevant to classification in this group
This subclass/group does not cover:
Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
Adding secondary air to fuel-air mixture
Fuel injection apparatus working simultaneously on two or more fuels
Informative references
Attention is drawn to the following places, which may be of interest for search:
Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel or fuel-air mixtures of engines
Synonyms and Keywords

In patent documents the following abbreviations are often used:

EGR
Exhaust Gas Recirculation
PCV
Positive Carter Ventilation
Apparatus for treating combustion-air, fuel, or fuel-air mixture, by catalysts, electric means, magnetism, rays, sound waves, or the like
Definition statement
This subclass/group covers:

Apparatus for treating combustion-air, fuel or fuel-air mixture by catalysts, electric means, magnetism, (radioactive) rays or sound waves in order to improve the combustibility of the fuel-air-mixture.

Relationship between large subject matter areas

Chemical, physical or physic-chemical processes in general; their relevant apparatus, B01J 19/00.

References relevant to classification in this group
This subclass/group does not cover:
Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
Apparatus for thermally treating combustion-air, fuel or fuel-air mixture
Informative references
Attention is drawn to the following places, which may be of interest for search:
Other methods of operating engines involving pre-treating of or adding substances to combustion air, fuel or fuel-air mixture for the engine.
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Sonic waves
Sound waves
Apparatus for re-atomising condensed fuel or homogenising fuel-air mixture (combined with secondary-air supply F02M 23/12) [N: (collecting condensed fuel F02M 33/02)]
Definition statement
This subclass/group covers:

Especially when the air is cold the process of vaporisation of fuel into the air is more difficult. Apparatus for re-atomising condensed fuel, e.g. fuel droplets on the inner side of the air intake tube, or homogenising fuel-air mixture, e.g. distribution of fuel and air, help to improve this process.

Relationship between large subject matter areas

Modifying induction systems for imparting a rotation to the charge in the cylinder, F02B 31/00.

References relevant to classification in this group
This subclass/group does not cover:

This group does not cover

Combined with secondary-air supply
Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture
Apparatus for collecting and returning condensed fuel
Informative references
Attention is drawn to the following places, which may be of interest for search:
Apparatus for adding secondary air to fuel-air mixture
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Secondary air
Air entering the intake via an extra opening
Synonyms and Keywords

In patent documents the following expressions "Re-atomising " and "Re-evaporating" are often used as synonyms.

Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture (F02M 21/06, F02M 21/10 take precedence; such apparatus being part of a carburettor or fuel-injection apparatus F02M 15/00, F02M 53/00; adding hot secondary air to fuel-air mixture F02M 23/14)
Definition statement
This subclass/group covers:

Apparatus for thermally treating combustion-air, fuel or fuel-air mixture for improving the combustion properties of the fuel-air mixture.

Relationship between large subject matter areas

Carburettors with heating, F02M 15/00; fuel injection apparatus with heating, F02M 53/00; fuel filters with heating, F02M 37/223; air filters with heating, F02M 35/024.

References relevant to classification in this group
This subclass/group does not cover:
Such apparatus being part of the carburettor
Apparatus for de-liquefying gas by heating
Heating means for fuels with low melting point
Adding hot secondary air to the fuel-air mixture
Such apparatus being part of the fuel injection apparatus
Informative references
Attention is drawn to the following places, which may be of interest for search:
Apparatus for treating combustion-air, fuel or fuel-air mixture by catalysts, electric means, magnetism, rays, sound waves or the like
Other apparatus for treating combustion-air, fuel, or fuel-air mixture (combustion-air cleaners F02M 35/00; arrangements for purifying liquid fuel F02M 37/22)
Definition statement
This subclass/group covers:

Other apparatus for treating combustion-air, fuel or fuel-air mixture, like collectors for condensed fuel, coatings of intake passages.

Relationship between large subject matter areas

Engine pertinent apparatus for adding for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture, F02M 25/00.

References relevant to classification in this group
This subclass/group does not cover:
Combustion-air cleaners
Arrangements for purifying liquid fuel
Informative references
Attention is drawn to the following places, which may be of interest for search:
Apparatus for re-atomising condensed fuel or homogenising fuel-air mixture
Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines (air cleaners in general B01D)
Relationship between large subject matter areas

F02M 35/00 has relationships with many subject matter areas in the field F02B, F02D and F02M dealing with the air and fuel supply to the internal combustion engine.

References relevant to classification in this group
This subclass/group does not cover:
Air cleaners in general
Informative references
Attention is drawn to the following places, which may be of interest for search:
Use of kinetic or wave energy of charge in induction systems
Modifying induction systems for imparting a rotation to the charge in the cylinder
Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus (F02M 69/00 takes precedence; [N: fuel injection apparatus characterised by their conduits and venting means F02M 55/00; fuel injection apparatus having a common rail F02M 63/0225; control of fuel feeding F02D 33/003; feeding liquid fuel to combustion apparatus, in general F23K 5/00; fuel supply to apparatus for generating combustion products of high pressure or high velocity F23R 3/28 ); Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines (separating apparatus, filters per se B01D; centrifuges B04B)
Definition statement
This subclass/group covers:

Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus, like pumps, fuel conduits and venting means.

Relationship between large subject matter areas

Fuel injection apparatus characterized by their conduits and venting means, F02M 55/00

References relevant to classification in this group
This subclass/group does not cover:
Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
Centrifuges
Control of fuel feeding
Fuel injection apparatus having a common rail
Feeding liquid fuel to combustion apparatus, in general
Fuel supply to apparatus for generating combustion products of high pressure or high velocity
Arrangements of fuel-injection apparatus with respect to engines; Pump drives adapted to such arrangements (arrangements of injectors F02M 61/14)
Definition statement
This subclass/group covers:

E.g. the physical relation of fuel-injection apparatus to an engine or the drive arrangement of a fuel pump.

References relevant to classification in this group
This subclass/group does not cover:
Arrangements of injectors with respect to engines
Informative references
Attention is drawn to the following places, which may be of interest for search:
Charging fuel-injection engines
Fuel-injection apparatus carrying the fuel into cylinders by high-pressure gas
Low-pressure fuel-injection
Arrangements of fuel-injection apparatus to facilitate the driving of pumps; Arrangements of fuel-injection pumps; Pump drives (F02M 49/00 takes precedence)
Definition statement
This subclass/group covers:

Arrangements of fuel-injection pumps including mounting, i.e. fitting or attaching the pumps to the engines.

Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor
Definition statement
This subclass/group covers:

Fuel injection apparatus having a driven sequential distributor, combined with or separated from a pump or common pressure source.

Injection pumps for metering and distributing fuel.

References relevant to classification in this group
This subclass/group does not cover:
Common rail or accumulator injection systems
Synonyms and Keywords

In patent documents the word "pump" is often used with the meaning "distributor-type pumps".

the distributor rotating
References relevant to classification in this group
This subclass/group does not cover:
Radial pistons carried by the distributor
[N: with piston arranged axially to driving shaft (F02M 41/123 takes precedence)]
References relevant to classification in this group
This subclass/group does not cover:
Characterised by means for varying fuel delivery or injection timing
[N: with piston arranged radially to driving shaft (F02M 41/123 takes precedence)]
References relevant to classification in this group
This subclass/group does not cover:
Characterised by means for varying fuel delivery or injection timing
[N: Throttling of fuel passages to or from the pumping chamber]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of valves
[N: Variably-timed valves controlling fuel passages]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of valves
[N: valves being mechanically or electrically adjustable sleeves slidably mounted on rotary piston]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of valves
[N: valves being fluid-actuated slide-valves, e.g. differential rotary-piston pump]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of valves
[N: Arrangements for metering fuel admitted to pumping chambers, e.g. by shuttles or by throttle-valves]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of valves
Fuel-injection apparatus operating simultaneously on two or more fuels or on a liquid fuel and another liquid, e.g. the other liquid being an anti-knock additive
Definition statement
This subclass/group covers:

Fuel injection apparatuses operating simultaneously on two or more fuels or on a liquid fuel and another liquid, the other liquid can e.g. be an antiknock additive, e.g. water.

One of the fuels may be gaseous.

This group does not contain documents describing gaseous fuel injection system. It is limited to constructional aspects of pumps or injectors.

However fuel injection apparatuses operating simultaneously on two or more fuels, one of them being gaseous, also fall under F02M 43/00.

References relevant to classification in this group
This subclass/group does not cover:
Engines operating on gaseous fuel
Engines operating on other non-liquid fuels
Injection valves for gaseous fuels
F02M21/02A
Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel, or fuel-air mixture
Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship (fuel-injectors having such deliveries by means of valves furnished at seated ends with pintle- or plug-shaped extensions F02M 61/06) [N:pumps having such delivery by means of delivery valves F02M 59/462]
Definition statement
This subclass/group covers:

Both functional and constructional aspects of injection apparatus. When a pump or injector is specially designed for such injection, then they are classified in these groups.

References relevant to classification in this group
This subclass/group does not cover:
Controlling fuel injection
Synonyms and Keywords

In patent documents the following expressions/words "rate shaping", "pilot" and "main injection" are often used as synonyms.

with each cyclic delivery being separated into two or more parts
Definition statement
This subclass/group covers:

Apparatus with each cyclic delivery being separated into two or more parts or if there is "a continuous cyclic delivery with variable pressure", or

in case "each cyclic delivery" is not "separated into two or more parts", i.e. in case injector doesn't close between parts.

References relevant to classification in this group
This subclass/group does not cover:
Two or more closing springs acting on injection-valve, and "each cyclic delivery" is NOT "separated into two or more parts"
with a small initial part, [N: e.g. initial part for partial load and initial and main part for full load]
Definition statement
This subclass/group covers:

Functional and constructional aspects of injection apparatus.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Pumps having such delivery by means of delivery valves
Fuel-injectors having such deliveries by means of valves furnished at seated ends with pintle- or plug-shaped extensions
Synonyms and Keywords

In patent documents the following expressions/words "rate shaping", "pilot" and "main injection" are often used as synonyms.

[N: Having specially arranged spill port and spill contour on the piston (F02M 45/063 takes precedence)]
References relevant to classification in this group
This subclass/group does not cover:
Delivery stroke of piston being divided into two or more parts, e.g. by using specially shaped cams
[N: Having more than one injection-valve controlling discharge orifices]
Definition statement
This subclass/group covers:

Apparatus having more than one injection-valve controlling discharge orifices, even if "each cyclic delivery" is not "separated into two or more parts". Also used if there is "a continuous cyclic delivery with variable pressure".

providing a continuous [N: cyclic] delivery with variable pressure
Definition statement
This subclass/group covers:

Apparatus providing a continuous cyclic delivery with variable pressure. "Variable pressure" is understood to include "variable flow rate".

References relevant to classification in this group
This subclass/group does not cover:
If "2 or more closing springs are acting on injection-valve", even if, as here, "each cyclic delivery" is not "separated into two or more parts", but is "a continuous cyclic delivery with variable pressure"
If there is "more than one injection valve controlling discharge orifices", even if, as here, "each cyclic delivery" is not "separated into two or more parts", but is "a continuous cyclic delivery with variable pressure"
Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure (F02M 49/00 takes precedence; apparatus with injection valves opened by fuel pressure and closed by non-fluid means, see the groups providing for other characteristics)
Definition statement
This subclass/group covers:

Injectors only. The needle valves of these injectors are closed by a fluid pressure, with the exception of injectors classified in F02M 47/046

References relevant to classification in this group
This subclass/group does not cover:
Fuel-injection apparatus in which injection pumps are driven or injectors are actuated, by the pressure in engine working cylinder, or by impact by engine working piston
Fuel injectors with spring for needle closing and using fluid for assisting the spring force
Fuel injection valves opened by fuel pressure and closed by non-fluid means
Informative references
Attention is drawn to the following places, which may be of interest for search:
Solenoid or piezoelectric control valves used in these injectors
Apparatus with injection valves opened by fuel pressure and closed by non-fluid means
Low-pressure fuel-injection
[N: Mechanically actuated valves draining the chamber to release the closing pressure]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of valves
[N: Hydraulically actuated valves draining the chamber to release the closing pressure]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of valves
[N: Electrically actuated valves draining the chamber to release the closing pressure]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of injection valves
Details of control valves
using fluid, other than fuel, for injection-valve actuation
Definition statement
This subclass/group covers:

Using fuel for injection-valve actuation, provided that the fuel used for injection-valve actuation is not taking part of the injection or stems from a separate fuel line, i.e.:

Other fuel injectors peculiar thereto
Definition statement
This subclass/group covers:

Fuel injectors not covered by F02M 47/02 and F02M 47/04.

Fuel-injection apparatus in which injection pumps are driven or injectors are actuated, by the pressure in engine working cylinders, or by impact of engine working piston
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

Fuel-injection apparatus characterised by being operated electrically
Definition statement
This subclass/group covers:

E.g.: electrical wirings, pumps with electric plunger drive and injectors with electric needle drive (solenoid, piezoelectric etc.)

References relevant to classification in this group
This subclass/group does not cover:
Injectors with electric control valves
Pumps with electric control valves
specially for low-pressure fuel-injection ([N: F02M 51/005 takes precedence]; pumps per se F02M 51/04 )
References relevant to classification in this group
This subclass/group does not cover:
Pumps per se
Injectors per se
Arrangement of electrical wires and connections
Injectors peculiar thereto [N: with means directly operating the valve needle]
Definition statement
This subclass/group covers:

Injectors peculiar thereto, with electrical means directly or indirectly via a hydraulic or mechanical linkage operating the valve needle.

References relevant to classification in this group
This subclass/group does not cover:
Fluid pressure operated valve needles
Informative references
Attention is drawn to the following places, which may be of interest for search:
Injector details not provided for under F02M 51/06
[N:using piezo-electric or magnetostrictive operating means]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

References relevant to classification in this group
This subclass/group does not cover:
Valves in general actuated by piezo-electric means
Piezo-electric devices; Electrostrictive devices; Magnetostrictive devices; Processes or apparatus peculiar to the manufacture or treatment thereof or of parts thereof; Details thereof
Informative references
Attention is drawn to the following places, which may be of interest for search:
Linkage between operating means and valve member
[N: actuator being hollow, e.g. the needle passing through the hollow space]
Definition statement
This subclass/group covers:

Injectors featuring hollow actuators, e.g. the needle passing through the hollow space. Example:

[N: using electromagnetic operating means]
References relevant to classification in this group
This subclass/group does not cover:
Valves in general actuated by electromagnetic means
[N: having two or more electromagnets]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: acting on one mobile armature (F02M 51/0628 takes precedence)]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: having a stepped armature]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: having a spherically or partly spherically shaped armature, e.g. acting as valve body]
Definition statement
This subclass/group covers:

Illustrative examples of subject matter classified in this group.

[N: having a plate-shaped or undulated armature not entering the winding (if entering the winding F02M 51/0664)]
References relevant to classification in this group
This subclass/group does not cover:
Armatures entering the winding
[N: the armature acting as a valve]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: the armature having a valve attached thereto]
Definition statement
This subclass/group covers:

Armatures having a valve attached thereto or integrated therewith.

[N: the valve being a short body, e.g. sphere or cube]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: the valve being spherical or partly spherical]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: the valve being an elongated body, e.g. a needle valve]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: the body being hollow and its interior communicating with the fuel flow]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: the armature and the valve being allowed to move relatively to each other or not being attached to each other]
Definition statement
This subclass/group covers:

The armature and the valve being allowed to move relatively to each other or not being attached to each other or at least part of valve being flexible.

E.g.:

[N: the armature acting as a valve or having a short valve body attached thereto]
Definition statement
This subclass/group covers:

Illustrative examples of subject matter classified in this group.

Special rules of classification within this group

In cases where it cannot be easily determined whether the valve body attached to the armature is short or elongated both F02M 51/0667 and F02M 51/0671 should be used.

[N: the armature having an elongated valve body attached thereto]
Definition statement
This subclass/group covers:

The armature having an elongated valve body attached thereto, or the armature having an elongated valve body integrated therewith, e.g. the armature constituting in itself an elongated valve body. Eg.:

E.g.:

Special rules of classification within this group

In cases where it cannot be easily determined whether the valve body attached to the armature is short or elongated both F02M 51/0667 and F02M 51/0671 should be used.

[N: the valve body having cylindrical guiding or metering portions, e.g. with fuel passages]
Definition statement
This subclass/group covers:

The valve body having cylindrical guiding or metering portions, e.g. with fuel passages. E.g.:

[N: all portions having fuel passages, e.g. flats, grooves, diameter reductions]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

References relevant to classification in this group
This subclass/group does not cover:
If the passage isn't in the cylindrical guiding or metering portion, but in another part of the valve member, e.g. its central part
[N: the body being hollow and its interior communicating with the fuel flow (F02M 51/0675 takes precedence)]
Definition statement
This subclass/group covers:

This group covers

Illustrative example of subject matter classified in this group.

Special rules of classification within this group

In cases where it cannot be easily determined whether the valve body attached to the armature is short or elongated both F02M 51/0667 and the appropriate class/code F02M 51/0671+ should be used.

[N: the armature and the valve being allowed to move relatively to each other or not being attached to each other]
Definition statement
This subclass/group covers:

The armature and the valve being allowed to move relatively to each other or not being attached to each other or at least part of valve being flexible.

Example:

[N: and permanent magnets (F02M 51/0696 takes precedence)]
Definition statement
This subclass/group covers:

Injectors using electromagnetic operating means and permanent magnets

References relevant to classification in this group
This subclass/group does not cover:
Fuel injection apparatus characterised by the use of movable windings
[N: as valve or armature return means]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: characterised by the use of movable windings]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

Fuel-injection apparatus characterised by having heating, cooling or thermally-insulating means
Definition statement
This subclass/group covers:

E.g. injectors or common rails having heating, cooling or thermally-insulating means.

References relevant to classification in this group
This subclass/group does not cover:
Carburettors with heating, cooling or thermally insulating means
Apparatus for de-liquefying gaseous fuels by heating
Apparatus for heating fuels with low melting point
Adding hot secondary air to fuel-air mixture
Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture
with fuel-heating means, e.g. for vaporising
References relevant to classification in this group
This subclass/group does not cover:
Carburettors with heating, cooling or thermally insulating means
Apparatus for de-liquefying gaseous fuels by heating
Apparatus for heating fuels with low melting point
Adding hot secondary air to fuel-air mixture
Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture
Injectors with heating, cooling, or thermally-insulating means
References relevant to classification in this group
This subclass/group does not cover:
Carburettors with heating, cooling or thermally insulating means
Apparatus for de-liquefying gaseous fuels by heating
Apparatus for heating fuels with low melting point
Adding hot secondary air to fuel-air mixture
Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture
with fuel-heating means, e.g. for vaporising
References relevant to classification in this group
This subclass/group does not cover:
Carburettors with heating, cooling or thermally insulating means
Apparatus for de-liquefying gaseous fuels by heating
Apparatus for heating fuels with low melting point
Adding hot secondary air to fuel-air mixture
Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture
Fuel-injection apparatus characterised by their fuel conduits or their venting means; [N: Arrangements of conduits between fuel tank and pump F02M 37/00 (venting in general B01D 19/00)]
Definition statement
This subclass/group covers:

E.g. fuel conduits between pump and injector, their coupling, constructional aspects of accumulators or common rails.

References relevant to classification in this group
This subclass/group does not cover:
Venting in general
Fuel feed and filtering systems
Arrangements of conduits between fuel tank and pump and apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus
General layout of a common rail system with fuel circuit and valving for control of fuel pressure
Low pressure fuel rails and fuel circuits
Pipes in general
[N: Joints; Sealings]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Joints in general
Sealings in general
Sealing arrangements between injector and engine, e.g. to avoid leakage of combustion chamber gases to the outside through the space between fuel injector and engine
R02M63/00T85S
Sealing of fuel injection apparatus not otherwise provided for
R02M63/00T130
[N: Venting means]
Definition statement
This subclass/group covers:

Venting means, i.e. for venting gases.

[N: Arrangement of fuel passages inside of injectors]
Definition statement
This subclass/group covers:

Specific arrangements or details of fuel passages inside injectors. E.g.

or

Fuel-injectors combined or associated with other devices
Definition statement
This subclass/group covers:

E.g.: pump-injectors; injectors combined with sensors;

injectors combined with engine valves and injectors having spark plugs.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Electric drive of fuel pumps
Hydraulic drive of reciprocating piston in fuel pumps
Pneumatic drive of reciprocating piston in fuel pumps
Pumps specially adapted for fuel-injection and not provided for in groups F02M 39/00 to F02M 57/00, [N: e.g. rotary cylinder-block type pumps (general features of pumps F04)]
Definition statement
This subclass/group covers:

Details of the pumps of F02M 41/00, F02M 43/00, F02M 51/00.

Plunger sealing, valve structure, materials etc: F02M 59/44 to F02M 59/485.

The structure of this group is close to the general layout of the IPC classification, i.e. it comprises a constructional part (groups F02M 59/02-F02M 59/18), a functional part (groups F02M 59/20-F02M 59/42) and general part with details, manufacturing (F02M 59/44-F02M 59/485).

References relevant to classification in this group
This subclass/group does not cover:
Rotary distributor type pumps, dual fluid pumps and electrically driven pumps
with cylinders arranged radially to driving shaft, e.g. in V or star arrangement
Definition statement
This subclass/group covers:

Reciprocating piston type pumps with cylinders arranged radially to driving shaft, e.g. in V or star arrangement. "arranged radially" is interpreted to be understood as excluding in-line pumps.

fuel delivery being controlled by means of fuel-displaced auxiliary pistons, which effect injection [N: (combined with rotary distributor supporting pump pistons F02M 41/1422; low pressure fuel-injection F02M 69/12)]
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Auxiliary pistons
Pistons that do not provide pressure intensification but act as metering pistons effecting injection.
by variably-timed valves controlling fuel passages [N: to pumping elements or overflow passages]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of valves
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Overflow passages
any draining passage wherever it is situated, even after (e.g. downstream of) the pump or the delivery valve. Generally, it is the pumping chamber that is drained.
[N: valves rotating (combined with rotary fuel distributor F02M 41/063)]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Rotary fuel distributor
Details of valves
[N: Valves being actuated electrically]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of valves
[N: Pump inlet valve of the check valve type being actuatable to open]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: Pump inlet valves being closed when actuated]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

for starting of engines [N: (supply of excess fuel F02M 59/447)]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Supply of excess fuel
Valves (in general F16K)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of valves
Valves in general
[N: Electrically operated valves, e.g. using electromagnetic or piezo-electric operating means]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Solenoid valves that control fuel amount delivered
Valve details
Fuel-injectors not provided for in groups F02M 39/00 to F02M 57/00 or F02M 67/00
Definition statement
This subclass/group covers:

Constructional parts (F02M 61/02-F02M 61/12) and a general, details part (F02M 61/16-F02M 61/205).

References relevant to classification in this group
This subclass/group does not cover:
Mounting of injectors with respect to engines
[N: Means for adjusting injection-valve lift]
Definition statement
This subclass/group covers:

Means for adjusting injection-valve lift during operation of the valve, in order to adjust it to the operating conditions and requirements of the moment.

[N: Filtering elements specially adapted in fuel inlets to injector]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Edge filtering elements
Filters adapted for location in special places, e.g. in pipe-lines, pumps
For fuel feed systems
[N: Assembling; Disassembling; Manufacturing; Adjusting]
Definition statement
This subclass/group covers:

Assembling; Disassembling; Manufacturing and Adjusting in the sense of calibrating during manufacture.

Injection nozzles, e.g. having valve seats; [N: Details of valve member seated ends, not otherwise provided for]
Informative references
Attention is drawn to the following places, which may be of interest for search:
The valves opening in direction of fuel flow
[N: Discharge orifices having different orientations with respect to valve member direction of movement, e.g. orientations being such that fuel jets emerging from discharge orifices collide with each other]
Definition statement
This subclass/group covers:

Discharge orifices arranged so that the jets are flowing therethrough at an angle to the normal axis of the injector.

[N: Discharge orifices being situated in different transversal planes with respect to valve member direction of movement]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

Discharge orifices having changing cross sections, e.g. being divergent
Definition statement
This subclass/group covers:

Discharge orifices having variable cross section, e.g. divergent, convergent or stepwise changing cross section. E.g.:

[N: Dimensional characteristics of discharge orifices]
Definition statement
This subclass/group covers:

E.g. the exact size, diameter is given, or a special relationship between a diameter and a length is given.

[N: Means specially adapted for varying the spring tension or assisting the spring force to close the injection-valve, e.g. with damping of valve lift]
References relevant to classification in this group
This subclass/group does not cover:
Fuel injectors of the accumulator type having a spring whose force assists the hydraulic closing of the injection valve
Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M 39/00 to F02M 57/00 or F02M 67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M 39/00 to F02M 61/00 or F02M 67/00; [N: Combination of fuel pump with other devices, e.g. lubricating oil pump]
Definition statement
This subclass/group covers:

Most active subgroup in this group is F02M 63/0225 dealing with the common rails. The groups F02M 63/0003 - F02M 63/0008 include injection system having a fuel pressure source and an on/off valve in each fuel conduit to injector. These systems are different from accumulator type fuel injectors classified in F02M 47/02. Also these valves have different function than the control valves in the fuel injection pumps defined by the groups F02M 59/36-F02M 59/366.

[N: Valves (for fuel metering see the relevant groups, e.g. F02M 59/34; inlet or outlet check valves for fuel injection pumps F02M 59/46; for fuel injectors see the relevant groups, e.g. F02M 61/00)]
Definition statement
This subclass/group covers:

Valves other than fuel injection valves, i.e. fuel injectors, whenever relevant.

References relevant to classification in this group
This subclass/group does not cover:
Valves in general
Metering fuel by means of valves in fuel-injection pumps
Metering fuel by means of throttling valves in fuel-injection pumps
Valves used in fuel-injection pumps only and not provided for in F02M 39/00 to F02M 57/00, e.g. inlet or outlet check valves for fuel-injection pumps
Informative references
Attention is drawn to the following places, which may be of interest for search:
Valves in general
Special rules of classification within this group

Not to be used to characterise fuel injection valves, i.e. fuel injectors, unless they have pertinent characteristics or have details, component parts or accessories not provided for in F02M 61/00, F02M 51/06, or Indexing Codes F02M 2063/0082.

The valves in F02M 63/0012 may be part of fuel injection apparatus for which there exist specific classes elsewhere, and which are thus classified both in that specific class and in F02M 63/0012, if the valve has a relevant feature per se.

[N: using electromagnetic operating means]
References relevant to classification in this group
This subclass/group does not cover:
Electromagnetic valves per se
Informative references
Attention is drawn to the following places, which may be of interest for search:
Electromagnetic valves per se
[N: characterised by the arrangement of electromagnets or fixed armatures]
Definition statement
This subclass/group covers:

The fixed armature is the magnetic core that does not move.

Synonyms and Keywords

In patent documents the following expressions/words "pole piece", "magnetkern" and "stator" are often used as synonyms.

[N: Lift valves, i.e. having a valve member that moves perpendicularly to the plane of the valve seat]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: Poppet valves, i.e. having a mushroom-shaped valve member that moves perpendicularly to the plane of the valve seat]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: with spherical or partly spherical shaped valve member ends]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

[N: Combined valve units, e.g. for controlling pumping chamber and injection valve]
Definition statement
This subclass/group covers:

Valve unit controlling more than one function.

[N: Pressure relief valves]
Definition statement
This subclass/group covers:

Valves that open when a specific pressure has been reached.

References relevant to classification in this group
This subclass/group does not cover:
Pure check valves
Informative references
Attention is drawn to the following places, which may be of interest for search:
Pressure relief valves in general
Synonyms and Keywords

In patent documents the following expressions " pressure limiting valve", "pressure safety valves" and "overpressure safety valves" are often used as synonyms.

[N: Check valves (F02M 59/462, F02M 59/464 take precedence)]
References relevant to classification in this group
This subclass/group does not cover:
Pressure relief valves
Fuel pump delivery valves
Fuel pump inlet valves of the check valve type
Informative references
Attention is drawn to the following places, which may be of interest for search:
Check valves in general
[N: Throttling valves, e.g. having variable opening positions throttling the flow]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Varying fuel delivery of a fuel pump in quantity or timing by throttling of passages to pumping elements or of overflow passages
[N: for cutting-out pumps or injectors in case of abnormal operation of the engine or the injection apparatus, e.g. over-speed, break-down of fuel pumps or injectors (safety devices acting on engine fuel system on lubricant pressure failure F01M 1/24); for cutting-out pumps for stopping the engine]
References relevant to classification in this group
This subclass/group does not cover:
Safety devices acting on engine fuel system upon lubricant pressure failure
[N: Fuel-injection apparatus having a common rail feeding several injectors (F02M 63/0003 takes precedence); Means for varying pressure in common rails; Pumps feeding common rails]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Constructional details of common rails
Testing fuel-injection apparatus, e.g. testing injection timing [N: (testing of ignition F02P 17/00; measuring fuel consumption G01F 9/00 ); Cleaning of fuel-injection apparatus]
Definition statement
This subclass/group covers:

Testing of fuel injection apparatus.

Testing injection timing.

Measuring injector spray angle

Quality check of fuel-injection apparatus.

Monitoring the function of the fuel injection apparatus in situ, e.g. for monitoring injection timing or injection quantity, or malfunction detection.

References relevant to classification in this group
This subclass/group does not cover:
Testing of ignition
Measuring fuel consumption
Informative references
Attention is drawn to the following places, which may be of interest for search:
Cleaning hollow articles by methods or apparatus specially adapted thereto
Safety or indicating devices for abnormal conditions
[N: Measuring variation of fuel pressure in high pressure line]
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in this group.

Apparatus in which fuel-injection is effected by means of high-pressure gas, the gas carrying the fuel into working cylinders of the engine, e.g. air-injection type (using compressed air for low-pressure fuel-injection apparatus F02M 69/08)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Control aspects of fuel injection by means of high-pressure gas:
Using compressed air for low-pressure fuel-injection apparatus:
Special rules of classification within this group

These groups relate mostly to old technology, however there are some recent inventions. These groups can overlap with the group F02M 69/08. The classification can be made in both groups.

Low-pressure fuel-injection apparatus(electrically operated F02M 51/00);Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
Definition statement
This subclass/group covers:

Low pressure fuel injection apparatuses. That normally means gasoline fuel injection. However in the recent years with common rail technology development the gap between diesel fuel injection and gasoline fuel injection has become very narrow. Therefore, it is more practical to classify the details of gasoline fuel injection apparatus just in the groups F02M 41/00-F02M 63/00. In specific cases and the injection of fuel in the air inlet manifold, the inventions are classified in the subgroups of F02M 69/00.

References relevant to classification in this group
This subclass/group does not cover:
High pressure gasoline common rail fuel injection systems
Details of gasoline fuel injection apparatus
Specific cases and the injection of fuel in the air inlet manifold
Special rules of classification within this group

Low pressure fuel injection apparatuses means normally gasoline fuel injection. However in the recent years with common rail technology development the gap between diesel fuel injection and gasoline fuel injection has become very narrow. Therefore, it is more practical to classify the details of gasoline fuel injection apparatus just in the groups F02M 41/00-F02M 63/00. In specific cases and the injection of fuel in the air inlet manifold, the inventions are classified in the subgroups of F02M 69/00.

Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Low pressure fuel injection
fuel injection in which the fuel-air mixture containing fuel thus injected will be substantially compressed in the compression stroke of the engine. Traditionally, the concept of "low-pressure" fuel-injection is associated with spark ignition engines, where the mixture is compressed.
High-pressure fuel-injection
fuel-injection being associated with compression ignition engines, where fuel is injected after compression of the air.
[N: characterised by means for intermittently metering the portion of fuel injected (F02M 69/12, F02M 69/14 take precedence)]
References relevant to classification in this group
This subclass/group does not cover:
Low-pressure fuel-injection apparatus comprising a fuel-displaced free-piston for intermittently metering and supplying fuel to injection nozzles
Low-pressure fuel-injection apparatus having cyclically-operated valves connecting injection nozzles to a source of fuel
[N: for injecting into the combustion chamber (F02M 69/046 takes precedence)]
Definition statement
This subclass/group covers:

The injection nozzle opening into the engine cylinder for direct injection, i.e. in-cylinder injection.

[N: for injecting into both the combustion chamber and the intake conduit]
Definition statement
This subclass/group covers:

One injector injecting fuel in the intake plus one injector injecting directly into the combustion chamber.

comprising a fuel-displaced free-piston for intermittently metering and supplying fuel to injection nozzles [N: (high-pressure fuel-injection with fuel-displaced auxiliary pistons F02M 59/32)]
References relevant to classification in this group
This subclass/group does not cover:
High-pressure fuel-injection with fuel-displaced auxiliary pistons
having cyclically-operated valves connecting injection nozzles to a source of fuel under pressure during the injection period [N: (high-pressure fuel injection apparatus F02M 63/0003)]
References relevant to classification in this group
This subclass/group does not cover:
High-pressure fuel injection apparatus
[N: the valves being actuated electrically (electrically-operated injectors F02M 51/06)]
References relevant to classification in this group
This subclass/group does not cover:
Electrically-operated injectors
characterised by means for facilitating the starting-up or idling of engines or by means for enriching fuel charge, e.g. below operational temperatures or upon high power demand of engines (at acceleration F02M 69/44)
References relevant to classification in this group
This subclass/group does not cover:
At acceleration
with an air by-pass around the air throttle valve or with an auxiliary air passage, e.g. with a variably controlled valve therein
References relevant to classification in this group
This subclass/group does not cover:
Constructional details of a throttle valve housing having a fluid by-pass
Informative references
Attention is drawn to the following places, which may be of interest for search:
Controlling the bypass for idle speed control
Combinations of carburettors and low-pressure fuel-injection apparatus (means for enriching charge on sudden air throttle opening of carburettors F02M 7/06)
References relevant to classification in this group
This subclass/group does not cover:
Means for enriching charge on sudden air throttle opening of carburettors
Subject matter not provided for in other groups of this subclass
This page is owned by Office of Patent Classification.
Last Modified: 10/11/2013