CPC Definition - Subclass F01B

Last Updated Version: 2024.01
MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES (of rotary-piston or oscillating-piston type F01C; of non-positive-displacement type F01D; internal-combustion aspects of reciprocating-piston engines F02B 57/00, F02B 59/00; 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)
Definition statement

This place covers:

Machines or engines, in general or of positive-displacement type

References
Limiting references

This place does not cover:

Rotary-piston or oscillating-piston type

F01C

Non-positive-displacement type

F01D

Informative references

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

Steam engine plants

F01K

Cyclically operating valves for machines or engines

F01L

Lubrication of machines or engines in general

F01M

Internal combustion engines

F02B

Internal combustion aspects of reciprocating piston engines

F02B 57/00; F02B 59/00

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

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

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.

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.

Pump

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

Positive displacement

Means 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

means 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

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

Rotary-piston machine

means 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

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

Free piston

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

Cylinders

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

Main shaft

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

Plant

means 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

means 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.

Reciprocating-piston machines or engines characterised by number or relative disposition of cylinders or by being built-up from separate cylinder-crankcase elements (F01B 3/00, F01B 5/00 take precedence)
References
Limiting references

This place does not cover:

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

F01B 3/00

Reciprocating-piston machines or engines with cylinder axes arranged substantially tangentially to a circle centred on main shaft axis

F01B 5/00

{the connection of the pistons with an element being at the outer ends of the cylinders}
Special rules of classification

Illustrative example of subject matter classified in F01B 1/0603

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{the connection of the pistons with an actuating or actuated element being at the inner ends of the cylinders}
Special rules of classification

Illustrative example of subject matter classified in F01B 1/062

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

Illustrative example of subject matter classified in F01B 3/00

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{having stationary cylinders}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0002

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{having two or more sets of cylinders or pistons}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0005

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{having self-acting distribution members, e.g. actuated by working fluid}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0008

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{Cylindrical distribution members}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0011

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{Conical distribution members}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0014

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{having rotary cylinder block}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0032

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{inclined to main shaft axis}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0038

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{Arrangements for pressing the cylinder barrel against the valve plate, e.g. fluid pressure}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0041

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{Particularities in the contacting area between cylinder barrel and valve plate}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0047

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{Bearing arrangements}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/005

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{Cylinder barrel}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0052

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{Conical valve means}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0061

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{Swash plate}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/007

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{Connection between cylinder barrel and inclined swash plate}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/0076

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{having pistons with rotary and reciprocating motion, i.e. spinning pistons}
Definition statement

This place covers:

having pistons with rotary and reciprocating motion, i.e. spinning pistons. The piston reciprocates and e.g. by means of a curved groove on the outer circumference will also rotate, (spin) along its longitudinal axis.

media18.jpg

References
Informative references

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

Piston motion being transmitted by curved surfaces, e.g. by cams or grooves

F01B 3/04.

Piston machines or pumps in which the valving is performed by pistons and cylinders coacting to open and close intake or outlet ports, the pistons and cylinders being relatively reciprocated and rotated

F04B 7/06

with wobble-plate
Special rules of classification

Illustrative example of subject matter classified in F01B 3/02

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the piston motion being transmitted by curved surfaces
Special rules of classification

Illustrative example of subject matter classified in F01B 3/04

media20.jpg

{by two or more curved surfaces, e.g. for two or more pistons in one cylinder}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/045

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by multi-turn helical surfaces and automatic reversal
Special rules of classification

Illustrative example of subject matter classified in F01B 3/06

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the helices being arranged on the pistons
Special rules of classification

Illustrative example of subject matter classified in F01B 3/08

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Control of working-fluid admission or discharge peculiar thereto (suitable for more general application F01L)
References
Informative references

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

Cyclically operating valves for machines or engines

F01L

{for machines with rotary cylinder block}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/103

media24.jpg

{by turning the valve plate}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/104

media25.jpg

{by changing the inclination of the swash plate}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/106

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{by turning the swash plate (with fixed inclination)}
Special rules of classification

Illustrative example of subject matter classified in F01B 3/108

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{by changing the inclination of the axis of the cylinder barrel relative to the swash plate (F01B 3/106 takes precedence)}
References
Limiting references

This place does not cover:

By changing the inclination of the swash plate

F01B 3/106

Special rules of classification

Illustrative example of subject matter classified in F01B 3/109

media28.jpg

Reciprocating-piston machines or engines with cylinder axes arranged substantially tangentially to a circle centred on main shaft axis
Special rules of classification

Illustrative example of subject matter classified in F01B 5/00

media29.jpg

{the connection of the pistons with an actuated or actuating element being at the outer ends of the cylinders}
Special rules of classification

Illustrative example of subject matter classified in F01B 5/003

media30.jpg

{the connection of the pistons with an actuated or actuating element being at the inner ends of the cylinders}
Special rules of classification

Illustrative example of subject matter classified in F01B 5/006

media31.jpg

Machines or engines with two or more pistons reciprocating within same cylinder or within essentially coaxial cylinders (in opposite arrangement relative to main shaft F01B 1/08)
References
Limiting references

This place does not cover:

Coaxial cylinders in opposite arrangement relative to main shaft

F01B 1/08

Special rules of classification

Illustrative example of subject matter classified in F01B 7/00

media32.jpg

with oppositely reciprocating pistons
Special rules of classification

Illustrative example of subject matter classified in F01B 7/02

media33.png

using only connecting-rods for conversion of reciprocatory into rotary motion or vice versa
Special rules of classification

Illustrative example of subject matter classified in F01B 7/06

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with side rods
Special rules of classification

Illustrative example of subject matter classified in F01B 7/08

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having piston-rod of one piston passed through other piston
Special rules of classification

Illustrative example of subject matter classified in F01B 7/10

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using rockers and connecting-rods
Special rules of classification

Illustrative example of subject matter classified in F01B 7/12

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acting on different main shafts
Special rules of classification

Illustrative example of subject matter classified in F01B 7/14

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with pistons synchronously moving in tandem arrangement
Special rules of classification

Illustrative example of subject matter classified in F01B 7/16

media39.jpg

with differential piston (F01B 7/20 takes precedence)
References
Limiting references

This place does not cover:

With two or more pistons reciprocating one within another

F01B 7/20

Special rules of classification

Illustrative example of subject matter classified in F01B 7/18

media40.jpg

with two or more pistons reciprocating one within another, e.g. one piston forming cylinder of the other
Special rules of classification

Illustrative example of subject matter classified in F01B 7/20

media41.jpg

Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups (connections disengageable during idling F01B 31/24)
Definition statement

This place covers:

Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups.

E.g. when no recognisable crank shaft is present or the main shaft is a cam shaft:

media42.jpg

References
Limiting references

This place does not cover:

Idling devices characterised by disengagement of connections between pistons and main shafts during idling

F01B 31/24

with crankshaft
Special rules of classification

Illustrative example of subject matter classified in F01B 9/02

e.g. non-conventional crankshafts:

media43.jpg

{of Bourke-type or Scotch yoke}
Special rules of classification

Illustrative example of subject matter classified in F01B 9/023

media44.jpg

with rotary main shaft other than crankshaft
Special rules of classification

Illustrative example of subject matter classified in F01B 9/04

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{the connections comprising gear transmissions}
Special rules of classification

Illustrative example of subject matter classified in F01B 9/042

media46.jpg

{with rack and pinion}
Special rules of classification

Illustrative example of subject matter classified in F01B 9/047

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the piston motion being transmitted by curved surfaces
Special rules of classification

Illustrative example of subject matter classified in F01B 9/06

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with ratchet and pawl
Special rules of classification

Illustrative example of subject matter classified in F01B 9/08

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Reciprocating-piston machines or engines without rotary main shaft, e.g. of free-piston type
References
Informative references

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

Free-piston combustion engines

F02B 71/00

{in which the movement in the two directions is obtained by one double acting piston motor}
Special rules of classification

Illustrative example of subject matter classified in F01B 11/001

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{one side of the double acting piston motor being always under the influence of the fluid under pressure}
Special rules of classification

Illustrative example of subject matter classified in F01B 11/002

media51.jpg

{the fluid under pressure being continuously delivered to one motor chamber and reacting the other chamber through a valve located in the piston, to bring the piston back in its start-position}
Special rules of classification

Illustrative example of subject matter classified in F01B 11/003

media52.png

FR2508568 A1

{in which the movement in the two directions is obtained by two single acting piston motors, each acting in one direction}
Special rules of classification

Illustrative example of subject matter classified in F01B 11/004

media53.jpg

{one single acting piston motor being always under the influence of the fluid under pressure}
Special rules of classification

Illustrative example of subject matter classified in F01B 11/006

media54.png

"...the steam supplied through the inlet 13 and the passage 12 enters the port 18, and acting upon the 1 upper face of the element 4 of the double piston (4,5), causes the latter to move downwards against the opposing action of the steam continuously supplied to the space 11...

{in which the movement in only one direction is obtained by a single acting piston motor, e.g. with actuation in the other direction by spring means}
Special rules of classification

Illustrative example of subject matter classified in F01B 11/007

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{with actuation in the other direction by gravity}
Special rules of classification

Illustrative example of subject matter classified in F01B 11/008

media56.jpg

{in which the movement in two directions is obtained by two or more double acting piston motors}
Special rules of classification

Illustrative example of subject matter classified in F01B 11/009

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Equalising or cushioning devices
Special rules of classification

Illustrative example of subject matter classified in F01B 11/02

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Engines combined with reciprocatory driven devices, e.g. hammers (with pumps F01B 23/08)
References
Limiting references

This place does not cover:

Adaptations of engines for driving, or combinations with, pumps

F01B 23/08

Special rules of classification

Illustrative example of subject matter classified in F01B 11/04

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for generating vibration only
Special rules of classification

Illustrative example of subject matter classified in F01B 11/06

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with direct fluid transmission link (F01B 11/02 takes precedence)
References
Limiting references

This place does not cover:

Equalising or cushioning devices

F01B 11/02

Special rules of classification

Illustrative example of subject matter classified in F01B 11/08

media61.jpg

Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion (machines or engines of flexible-wall type F01B 19/00)
References
Limiting references

This place does not cover:

Machines or engines of flexible-wall type

F01B 19/00

Informative references

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

Internal combustion engine aspects

F02B 57/00

with one cylinder only
Special rules of classification

Illustrative example of subject matter classified in F01B 13/02

media62.jpg

with more than one cylinder {(F01B 3/0032 takes precedence)}
Special rules of classification

Illustrative example of subject matter classified in F01B 13/04

media63.jpg

{with cylinder axes arranged substantially tangentially to a circle centred on main shaft axis}
Special rules of classification

Illustrative example of subject matter classified in F01B 13/045

media64.jpg

{the connection of the pistons with the actuated or actuating element being at the outer ends of the cylinders}
Special rules of classification

Illustrative example of subject matter classified in F01B 13/061

media65.jpg

{the connection of the pistons with an actuated or actuating element being at the inner ends of the cylinders}
Special rules of classification

Illustrative example of subject matter classified in F01B 13/068

media66.jpg

Reciprocating-piston machines or engines with movable cylinders other than provided for in group F01B 13/00 (with movable cylinder sleeves for working fluid control F01L)
Definition statement

This place covers:

Reciprocating-piston machines or engines with movable cylinders other than provided for in group F01B 13/00.

E.g. reciprocating-piston machines or engines having reciprocating cylinders or pivoting and oscillating cylinders.

References
Limiting references

This place does not cover:

Movable cylinder sleeves for working fluid control

F01L

Reciprocating-piston machines or engines characterised by use of uniflow principle
Definition statement

This place covers:

Reciprocating-piston machines or engines characterised by use of uniflow principle:

E.g. compressed gas engines where the working fluid enter a working cylinder, expands and then exits the cylinder.

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Glossary of terms

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

In patent document the word "uniflow" is often used with the meaning "open circuit where gas enters cylinder, expands, and is then released"

Engines
Definition statement

This place covers:

Compressed gas engines.

References
Informative references

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

Arrangement or mounting of steam or gaseous-pressure propulsion units of the piston type in vehicles

B60K 3/02

Arrangement or mounting of plural diverse prime-moves for mutual or common propulsion, prime movers comprising combustion engines and a chargeable fluidic accumulator

B60K 6/12

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

F02B 75/34

{with fluid heating}
Special rules of classification

Illustrative example of subject matter classified in F01B 17/022

media68.jpg

{using separators}
Definition statement

This place covers:

Separators for separating liquid or oil from compressed gas for gas engines.

Steam engines
References
Limiting references

This place does not cover:

Steam engine plants

F01K

Informative references

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

Toys

A63H

Ultra small engines:

F02B 75/34

Positive-displacement machines or engines of flexible-wall type
Definition statement

This place covers:

Positive-displacement machines or engines of flexible-wall type. E.g. where the piston is made of a diaphragm or bellows.

media69.jpg

with plate-like flexible members
Special rules of classification

Illustrative example of subject matter classified in F01B 19/02

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with tubular flexible members
Special rules of classification

Illustrative example of subject matter classified in F01B 19/04

media71.jpg

Combinations of two or more machines or engines (F01B 23/00 takes precedence; combinations of two or more pumps F04; fluid gearing F16H)
Definition statement

This place covers:

Combinations of two or more machines or engines. E.g. a combined internal combustion engine and steam engine.

References
Limiting references

This place does not cover:

Combinations of engines with devices driven thereby

F01B 23/00

Combinations of two or more pumps

F04

Adaptations of machines or engines for special use; Combinations of engines with devices driven thereby (F01B 11/00 takes precedence; fluid gearing F16H)
References
Limiting references

This place does not cover:

Reciprocating-piston machines or engines without rotary main shaft, e.g. of free-piston type

F01B 11/00

Adaptations of combustion engines for driving vehicles of for driving propellers

F02B 61/00

Adaptations of combustion engines for driving pumps, hand-held tools or electric generators; portable combinations of engine with engine-driven devices, e.g. with non driven apparatus

F02B 63/00

Informative references

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

Controlling combustion engines

F02D

Fluid gearing

F16H

Regulating, controlling, or safety means (regulating or controlling in general G05)
References
Limiting references

This place does not cover:

Controlling internal combustion engines

F02D

Controlling and regulating in general

G05

Starting of machines or engines (starting combustion engines F02N)
References
Limiting references

This place does not cover:

Starting combustion engines

F02N

Component parts, details, or accessories not provided for in, or of interest apart from, other groups (machine or engine casings, other than those peculiar to steam engines, F16M)
References
Informative references

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

Machine or engine casings, other than those peculiar to steam engines

F16M