​

CPC Definition - Subclass F15B

Printable version [PDF]
Last Updated Version: 2026.08
F15B
SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
Definition statement

This place covers:

Systems transferring mechanical energy by means of a fluid under pressure using the principles of fluid statics or hydrostatics, i.e. hydraulic or pneumatic systems

References
Application-oriented references

Examples of places where the subject matter of this place is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Fluid clutches or brakes

F16D

Fluid springs

F16F

Fluid gearing

F16H

Fluid-operating means for valves

F16K 31/12

Informative references

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

Hydraulically or pneumatically operated lifting devices for soil-working machines

A01B 63/10

Hydraulic drawing presses

B21D

Hydraulic or pneumatic manipulators

B25J

Hydraulic or pneumatic tipping devices for vehicles

B60P 1/00

Hydraulic or pneumatic remote control for railway signals

B61L 7/04

Desalination

B63J 1/00

Water purification

C02F 1/00

Hydraulic or pneumatic mine supports

E21D 15/44

Motors, turbines, compressors, blowers, pumps

F01 - F04

Steam engines

F01B

Engine water cooling

F01P 3/00

Fuel injection

F02M

Perpetua mobilia using fluid

F03B 17/00

Fluid signal amplifiers, relays

F15C

Fluid dynamics

F15D

Pistons, cylinders packing

F16J

Valves, taps, cocks, actuating-floats

F16K

Safety valves with auxiliary fluid operation of the main valve

F16K 17/10

Pipes, pipe joints

F16L

Lubricating

F16N

Central heating systems

F24D 3/00

Glossary of terms

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

Pneumatic

using air or an inert gas (except steam) as a pressure medium.

Hydraulic

using a liquid as the pressure medium.

Telemotor

system or device in which a substantially constant amount of fluid is trapped between an input member and an output member to act as a fluid link

Servomotor

fluid-pressure actuator, e.g. a piston and a cylinder, directly controlled by a valve or other device (e.g. pump) which is responsive to operation of an initial controlling member (e.g. joystick). The initial controlling member may be adjacent to the servomotor or at a distance and may be, e.g. a hand lever.

Installations or systems with accumulators; Supply reservoir or sump assemblies
References
Informative references

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

Hydro-pneumatic suspensions

B60G 17/056 , F16F 9/06

Pumps having reservoirs

F04B 41/04

Central heating systems

F24D 3/1008

Special rules of classification

The main group F15B 1/00 is complemented by the main group F15B 2201/00 and is used for classifying invention information only.

Glossary of terms

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

Accumulator

vessel for storing pressurised liquid (e.g. using a liquid and a gas chamber separated by a membrane or piston or using an elastic housing)

Installations or systems with accumulators
References
Informative references

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

Energy recuperation means

F15B 21/14

Glossary of terms

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

Accumulator

vessel for storing pressurised liquid (e.g. using a liquid and a gas chamber separated by a membrane or piston or using an elastic housing)

{used for damping}
References
Informative references

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

Pumps having accumulators for reducing pressure pulsations

F04B 11/0008

Hydro-pneumatic suspensions

F16F 9/08

Buffers for preventing water hammer

F16L 55/05

{used as an emergency power source, e.g. in case of pump failure}
References
Informative references

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

See also

F15B 2211/212

Special rules of classification

F15B 2211/212 takes precedence

{used as a supplementary power source, e.g. to store energy in idle periods to balance pump load}
Definition statement

This place covers:

Also for recuperation of hydraulic energy (as e.g. used in hydraulic excavators)

References
Informative references

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

Dredgers or soil-shifting machinery with energy recovery arrangements

E02F 9/2217

{used for thermal compensation, e.g. to collect expanded fluid and to return it to the system as the system fluid cools down}
References
Informative references

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

Central heating systems

F24D 3/1008

having accumulator charging devices
Definition statement

This place covers:

E.g. valves controlling flow of hydraulic fluid to and from the liquid chamber of an accumulator.

References
Informative references

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

Accumulator gas charging devices

F15B 1/08, F15B 2201/415

Control of fluid pressure in general

G05D 16/00

Accumulators
Definition statement

This place covers:

Vessel for storing pressurised liquid (e.g. using a liquid and a gas chamber separated by a membrane or piston or using an elastic housing).

References
Informative references

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

Pumps having accumulators for reducing pressure pulsations

F04B 11/0008

Hydro-pneumatic suspensions

F16F 9/08

Buffers for preventing water hammer

F16L 55/05

Pressure vessels per se

F17C 1/00

Central heating systems

F24D 3/1008

Special rules of classification

The sub-group F15B 1/04 is complemented by the main group F15B 2201/00

Synonyms and Keywords

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

  • "pressure accumulator", "Druckspeicher", "Hydrospeicher "and "Accumulateur"
  • "bladder-type accumulator" and "Blasenspeicher"
  • "membrane-type accumulator" and "Membranspeicher"
  • "accumulator using pistons" and "Kolbenspeicher"
  • "accumulators having springs" and "Federspeicher"
using a gas cushion; Gas charging devices; Indicators or floats therefor
References
Informative references

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

See also

F15B 2201/205

Special rules of classification

F15B 2201/205 takes precedence.

{the accumulator having a fusible plug}
Definition statement

This place covers:

Accumulators with a safety plugs that melt at a certain temperature for relieving the pressure.

{the gas cushion being entirely enclosed by the separating means, e.g. foam or gas-filled balls}
References
Limiting references

This place does not cover:

Accumulators using bladders

F15B 1/165

Informative references

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

See also

F15B 2201/3154

Special rules of classification

F15B 2201/3154 takes precedence.

with flexible separating means
References
Informative references

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

Accumulators with flexible separating means but without gas cushion

F15B 1/04

See also

F15B 2201/315

Special rules of classification

F15B 2201/315 takes precedence.

Accumulators not using a gas cushion are classified in F15B 1/04 even if they have flexible separating means (e.g. a membrane).

{the separating means being bellows}
Definition statement

This place covers:

Illustrative example of subject matter classified in this group.

media0.jpg

Fig. from US2004244857

References
Informative references

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

See also

F15B 2201/3153

Special rules of classification

F15B 2201/3153 takes precedence.

Synonyms and Keywords

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

  • "bellows", "Faltenbalg" and " soufflet"
{characterised by the way housing components are assembled}
References
Informative references

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

See also

F15B 2201/605

Special rules of classification

F15B 2201/605 takes precedence.

{characterised by the attachment means (F15B 1/14 takes precedence)}
Special rules of classification

F15B 1/14 takes precedence.

{in the form of a bladder}
Definition statement

This place covers:

Accumulators using bladders, i.e. essentially cylindrical flexible separating means having a first open end portion which is normally rounded and a second end portion with a fluid inlet for separating a hydraulic fluid and a gas. media1.png

Fig. from US2006042707

References
Informative references

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

See also

F15B 2201/3152

Special rules of classification

F15B 2201/3152 takes precedence.

Synonyms and Keywords

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

  • "bladder", "Blase" and "vessie"
  • " bladder-type accumulator", "Blasenspeicher" and "accumulateur à vessie"
Anti-extrusion means
References
Informative references

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

See also

F15B 2201/43

Special rules of classification

F15B 2201/43 takes precedence.

fixed to the separating means
References
Informative references

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

See also

F15B 2201/435

Special rules of classification

F15B 2201/435 takes precedence.

Liquid port constructions
References
Informative references

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

See also

F15B 2201/41

Special rules of classification

F15B 2201/41 takes precedence.

with rigid separating means, e.g. pistons
References
Informative references

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

See also

F15B 2201/31

Special rules of classification

F15B 2201/31 takes precedence.

Accumulators using springs and no gas cushion are classified in F15B 1/04 even if they have rigid separating means (e.g. a piston).

Supply reservoir or sump assemblies
References
Informative references

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

Reservoirs for vehicle braking systems

B60T 17/06

Fluid supply systems for power Power-steering systems with reservoirs

B62D 5/07

Pumps having reservoirs

F04B 41/04

{with pressurised main reservoir}
References
Informative references

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

Systems with accumulators

F15B 1/02

Intensifiers or fluid-pressure converters, e.g. pressure exchangers; Conveying pressure from one fluid system to another, without contact between the fluids {(fluid-driven pumps F04B 9/08)}
Definition statement

This place covers:

Devices for converting fluid energy, i.e. from a flow of fluid having high pressure and low flow rate to a flow of fluid having low pressure and high flow rate or vice versa.

E.g. devices using pistons of different size or rotating fluid pumps and motors of different capacity.

media2.png

Fig. from FR2822906

References
Limiting references

This place does not cover:

Fluid-driven pumps

F04B 9/08

Informative references

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

Pressure intensifiers in processes of separation using semi-permeable membranes, e.g. dialysis, osmosis

B01D 61/00

Fluid-driven pumps

F04B 9/08

Transducers converting variations of physical quantities, e.g. expressed by variations in positions of members, into fluid-pressure variations or vice versa; Varying fluid pressure as a function of variations of a plurality of fluid pressures or variations of other quantities (F15B 9/00 takes precedence)
References
Limiting references

This place does not cover:

Servomotors with follow-up action

F15B 9/00

Informative references

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

Transducers for measuring or controlling

G01, G05

Pressure sensors

G01L 9/00

Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
Definition statement

This place covers:

E.g. systems wherein a master cylinder is directly connected to a subordinate cylinder. Illustrative example:

media3.jpg

Fig. from WO2006129746

References
Informative references

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

Combinations of telemotor and servomotor systems

F15B 17/00

For control in motor vehicles

B60K

Vehicle brakes

B60T 1/08, B60T 1/093

For control in ships

B63H 25/00

For control in aircraft

B64C 13/00

Hydraulic clutch actuation

F16D 25/00

Hydraulic gear shifting devices

F16H 61/30

Glossary of terms

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

Telemotor

system or device in which a substantially constant amount of fluid is trapped between an input member and an output member to act as a fluid link, e.g. realised as a master cylinder which is directly connected to a subordinate cylinder.

{With multiple inputs, e.g. for dual control}
References
Informative references

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

Input units (e.g. master cylinders)

F15B 7/08

{With rotary or crank input}
References
Informative references

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

Input units

F15B 7/08

In which the ratio between pump stroke and motor stroke varies with the resistance against the motor
References
Informative references

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

In brake actuating systems for motor vehicles

B60T

Details (F15B 15/00 takes precedence)
Special rules of classification

F15B 15/00 takes precedence for subordinate cylinders.

Input units; Master units
References
Informative references

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

Vehicle brake master cylinders

B60T 11/16

Compensation of the liquid content in a system (F15B 7/08 takes precedence)
References
Limiting references

This place does not cover:

Details of input units or master units

F15B 7/08

Informative references

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

Pressure-maintaining arrangements for brake master cylinders

B60T 11/228

Servomotors with follow-up action, {e.g. obtained by feed-back control,} i.e. in which the position of the actuated member conforms with that of the controlling member
Definition statement

This place covers:

Fluid power drives using position feed-back

Glossary of terms

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

Servomotor

fluid-pressure acutator, e.g. a piston and a cylinder, directly controlled by a valve or other device (e.g. pump) which is responsive to operation of an initial controlling member (e.g. joystick). The initial controlling member may be adjacent to the servomotor or at a distance and may be, e.g. a hand lever.

in which the controlling element and the servomotor each controls a separate member, these members influencing different fluid passages or the same passage
Definition statement

This place covers:

Illustrative example of subject matter classified in this group.

media4.png

Fig. from US4733601

in which both the controlling element and the servomotor control the same member influencing a fluid passage and are connected to that member by means of a differential gearing
Definition statement

This place covers:

This class is also used for systems with a differential gear ratio of 1:1. Illustrative example:

media5.jpg

Fig. from FR74115

Systems essentially having two or more interacting servomotors {, e.g. multi-stage (F15B 18/00, F15B 20/00 take precedence)}
Definition statement

This place covers:

E.g. multi-stage systems

References
Limiting references

This place does not cover:

Parallel arrangements of independent servomotor systems

F15B 18/00

Safety arrangements therefor

F15B 20/00

Informative references

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

Servo-operated pilot valves for the following stage

F15B 13/042

Servomotor systems without provision for follow-up action {; Circuits therefor} (F15B 3/00 takes precedence)
Definition statement

This place covers:

Servomotor systems and fluid circuits of general application, without provision for follow-up action, for moving a servomotor.

References
Informative references

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

Agricultural machines

A01B

Control arrangements for fluid-driven presses

B30B 15/16

Resilient vehicle suspensions having means for adjusting the spring or vibration-damper characteristics

B60G 17/00

Hydraulic brakes

B60T 11/10

Power-assisted or power-driven steering using fluid

B62D 5/06

Hydraulic lifting devices movable with their loads

B66F 9/22

Hydraulic or pneumatic drives for dredgers or soil-shifting machines

E02F 9/22

External control of clutches by fluid pressure

F16D 48/02

Hydrostatic control of exclusively fluid gearing

F16H 61/40

Valves

F16K

Special rules of classification

The main group F15B 11/00 is complemented by the indexing group F15B 2211/00 which is used for classifying additional information only.

The reference to F15B 3/00 is non-limiting in main group F15B 11/00. CPC will be updated once this inconsistency is resolved in IPC.

Glossary of terms

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

servomotor

fluid-pressure actuator, e.g. a piston and a cylinder, directly controlled by a valve or other device, e.g. a pump, which is responsive to operation of an initial controlling member. The initial controlling member may be adjacent to the servomotor or at a distance, and may be, for example, a hand lever or a joystick.

{Systems with load-holding valves}
Definition statement

This place covers:

Releasable check valves and proportional braking valves.

Illustrative example of subject matter classified in this place:

media37.png

References
Informative references

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

Details of locking valves or other detent devices of servomotor systems

F15B 13/01

Load-holding valves as a component in a fluid pressure circuit of a servomotor

F15B 2211/30515

Synonyms and Keywords

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

  • "load holding valve" and "releasable check valve"
{Hydraulic "Wheatstone bridge" circuits, i.e. with four nodes, P-A-T-B, and on-off or proportional valves in each link}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media10.png

{in which a rapid approach stroke is followed by a slower, high-force working stroke (F15B 11/0325 takes precedence)}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media38.png

References
Limiting references

This place does not cover:

Servomotor systems without provision for follow-up action incorporating special features for controlling the actuating force of an output member by means of fluid-pressure converters increasing the working force after an approach stroke

F15B 11/0325

Informative references

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

Circuits for combined control of output members in servomotor systems

F15B 2211/775

by means of differential connection of the servomotor lines, e.g. regenerative circuits
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media39.png

References
Informative references

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

Valves for interconnecting the fluid chambers of an actuator

F15B 13/021

Circuits for servomotor systems with directional control valves having a regenerative position

F15B 2211/3133

{the regenerative circuit being activated or deactivated automatically}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media11.png

{with variable regeneration flow}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media12.png

for controlling the actuating force (F15B 11/024 takes precedence)
References
Limiting references

This place does not cover:

Servomotor systems for controlling the speed or actuating force of an output member by means of differential connection of the servomotor lines, e.g. regenerative circuits

F15B 11/024

Informative references

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

Circuits for control of force or torque of an output member in servomotor systems

F15B 2211/76

by means of fluid-pressure converters
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media40.png

References
Informative references

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

Fluid pressure converters

F15B 3/00

{the fluid-pressure converter increasing the working force after an approach stroke}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media13.png

by means of servomotors having a plurality of working chambers
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media41.png

References
Informative references

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

Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith

F15B 15/00

{Tandem constructions}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media14.png

{during starting or stopping (F15B 11/048 takes precedence)}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media42.png

References
Limiting references

This place does not cover:

Servomotor systems without provision for follow-up action for controlling the speed of an output member depending on the position of the working member with deceleration control

F15B 11/048

Informative references

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

Circuits for control of acceleration or deceleration of the output member in servomotor systems

F15B 2211/755

Circuits for servomotor control during starting

F15B 2211/851

Circuits for servomotor control during stopping

F15B 2211/853

{in one direction only, with no control in the reverse direction, e.g. check valve in parallel with a throttle valve}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media15.png

by means in the feed line (F15B 11/046, F15B 11/05 take precedence)
Definition statement

This place covers:

Servomotor systems essentially incorporating special features for controlling the speed of an output member by means in the feed line, i.e. "meter in".

Illustrative example of subject matter classified in this place:

media43.png

References
Limiting references

This place does not cover:

Servomotor systems without provision for follow-up action for controlling the speed of an output member, the speed depending on the position of the working member

F15B 11/046

Servomotor systems without provision for follow-up action specially adapted to maintain constant speed force of an output member

F15B 11/05

Informative references

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

Circuits for servomotor systems with directional control combined with flow control by regulating means in feed line, i.e. meter-in control

F15B 2211/351

{by controlling pump output or bypass, other than to maintain constant speed}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media44.png

References
Informative references

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

Servomotor systems without provision for follow-up action specially adapted to maintain constant speed of an output member by adjusting the pump output or bypass

F15B 11/055

{by controlling the number of pumps or parallel valves switched on}
Definition statement

This place covers:

Systems controlling the speed by means of digital valves or by means of systems using pulse code modulation [PCM].

Illustrative examples of subject matter classified in this place:

1.

media45.png

2.

media46.png

References
Informative references

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

Circuits for flow control in servomotor systems with multiple valves in parallel flow paths

F15B 2211/40592

by means in the return line (F15B 11/046, F15B 11/05 take precedence)
Definition statement

This place covers:

Servomotor systems essentially incorporating special features for controlling the speed of an output member by means in the return line, i.e. "meter out".

Illustrative example of subject matter classified in this place:

media47.png

References
Limiting references

This place does not cover:

Servomotor systems without provision for follow-up action for controlling the speed of an output member, the speed depending on the position of the working member

F15B 11/046

Servomotor systems without provision for follow-up action specially adapted to maintain constant speed force of an output member

F15B 11/05

Informative references

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

Circuits for servomotor systems with directional control combined with flow control by regulating means in return line, i.e. meter-out control

F15B 2211/353

{with counterbalance valves, e.g. to prevent overrunning or for braking}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media48.png

References
Informative references

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

Counterbalance valves for servomotor systems

F15B 13/029

Pressure control circuits for servomotor systems using counterbalance valves

F15B 2211/50581

depending on the position of the working member
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media16.png

with deceleration control
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media17.png

specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive {(F15B 11/161 takes precedence)}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media49.png

References
Limiting references

This place does not cover:

Maintaining constant speed in servomotor systems without provision for follow-up action with sensing of servomotor demand or load, for two or more servomotors

F15B 11/161

Informative references

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

Servomotor systems without provision for follow-up action for controlling the speed of an output member by means in the return line with counterbalance valves

F15B 11/0445

Fluid distribution or supply devices for use with a single servomotor with means or adapted for load sensing

F15B 13/0416

Circuits for servomotor systems with directional control valves in combination with pressure compensating valves

F15B 2211/3053

Flow control circuits for servomotor systems using pressure compensating valves

F15B 2211/40553

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

LS

load sensing

LUDV

load-independent flow distribution (German: lastdruckunabhängige Durchflussverteilung)

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

  • "pressure-compensated", "pressure compensator", "pressure compensating valve" and "LUDV"
{by adjusting the pump output or bypass (F15B 11/165 takes precedence)}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media50.png

References
Limiting references

This place does not cover:

Servomotor systems without provision for follow-up action with two or more servomotors with sensing of servomotor demand or load for adjusting the pump output or bypass in response to demand

F15B 11/165

Informative references

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

Circuits for pressure margin control in servomotor systems, e.g. pump pressure in relation to load pressure

F15B 2211/253

Pump control

F04B 49/00

involving features specific to the use of a compressible medium, e.g. air, steam
References
Informative references

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

Circuits for control specific to compressible fluids in servomotor systems

F15B 2211/8855

with devices for saving the compressible medium
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media18.png

with valves for gradually putting pneumatic systems under pressure
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media19.png

Combined pneumatic-hydraulic systems
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media20.png

References
Informative references

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

Servomotor systems without provision for follow-up action for controlling the actuating force of an output member by means of fluid-pressure converters

F15B 11/032

{with the driving energy being derived from a pneumatic system, a subsequent hydraulic system displacing or controlling the output element}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media21.png

with pneumatic drive or displacement and speed control or stopping by hydraulic braking
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media22.png

in which the servomotor position is a function of the pressure {; Pressure regulators as operating means therefor}
Definition statement

This place covers:

Servomotor systems without provision for follow-up action, with only one servomotor, in which the servomotor position is a function of the pressure. This place also covers pressure regulators therefor. The device itself may be a position indicating system.

Illustrative example of subject matter classified in this place:

media23.png

providing distinct intermediate positions; with step-by-step action
References
Informative references

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

Servomotor systems without provision for follow-up action with two or more servomotors used in combination for obtaining stepwise operation of a single controlled member

F15B 11/18

Restricting the stroke of fluid-actuated devices for displacing a member from one position to another

F15B 15/24

{providing distinct intermediate positions}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media24.png

References
Informative references

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

Servomotor systems without provision for follow-up action with only one servomotor providing distinct intermediate positions or with step-by-step action using separate dosing chambers of predetermined volume

F15B 11/13

{by means of actuators with multiple stops}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media25.png

{by means of actuators with fluid-operated stops}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media26.png

{by means of digital actuators, i.e. actuators in which the total stroke is the sum of individual strokes}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media27.png

{by means of actuators of the standard type with special circuit controlling means (F15B 11/125 takes precedence)}
Definition statement

This place covers:

Illustrative examples of subject matter classified in this place:

1.

media28.png

2.

media29.png

References
Limiting references

This place does not cover:

Servomotor systems without provision for follow-up action with only one servomotor providing distinct intermediate positions by means of digital actuators, i.e. actuators in which the total stroke is the sum of individual strokes

F15B 11/125

{with step-by-step action}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media30.png

{by means of actuators of the standard type with special circuit controlling means}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media31.png

using {separate dosing} chambers of predetermined volume
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media32.png

with special provision for automatic return
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media51.png

References
Informative references

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

Fluid gearing with oscillating input or output

F16H 43/00

with two or more servomotors
References
Informative references

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

Hydraulic or pneumatic drives for dredgers or soil-shifting machines

E02F 9/22

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

LS

load sensing

LUDV

load-independent flow distribution (German: lastdruckunabhängige Durchflussverteilung)

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

  • "pressure-compensated", "pressure compensator", "pressure compensating valve" and "LUDV"
{for giving priority to particular servomotors or users}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media52.png

References
Informative references

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

Details of flow dividers or priority valves

F15B 13/022

Flow control circuits for servomotor systems using flow dividers

F15B 2211/40523

Circuits for servomotor systems for control of multiple output members, one or more output members having priority

F15B 2211/781

Supply of pressurised fluid for power steering also supplying other consumers

B62D 5/07

{for sharing the pump output equally amongst users or groups of users, e.g. using anti-saturation, pressure compensation}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media53.png

References
Informative references

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

Fluid distribution or supply devices for use with a single servomotor with means or adapted for load sensing

F15B 13/0416

Circuits for servomotor systems with directional control valves in combination with pressure compensating valves

F15B 2211/3053

Flow control circuits for servomotor systems using pressure compensating valves

F15B 2211/40553

{for adjusting the pump output or bypass in response to demand}
Definition statement

This place covers:

Illustrative examples of subject matter classified in this place:

1.

media54.png

2.

media55.png

References
Informative references

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

Servomotor systems without provision for follow-up action specially adapted to maintain constant speed of an output member by adjusting pump output or bypass

F15B 11/055

Circuits for pressure margin control in servomotor systems, e.g. pump pressure in relation to load pressure

F15B 2211/253

Pump control

F04B 49/00

{Controlling a pilot pressure in response to the load, i.e. supply to at least one user is regulated by adjusting either the system pilot pressure or one or more of the individual pilot command pressures}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media33.png

{using pilot pressure to sense the demand}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media34.png

The Figure illustrates pilot pressure sensors (15a) and (15b) to indicate demand.

{with at least one load sense pressure being derived from a work port load pressure but not being the work port load pressure itself}
Definition statement

This place covers:

Sensing of servomotor demand or load with at least one load sense pressure being derived from a work port load pressure, but not being the work port load pressure itself, e.g. with an isolator valve or a duplicating valve.

Illustrative example of subject matter classified in this place:

media56.png

The Figure illustrates an isolator valve (80) providing a load sensing signal into line (82).

References
Informative references

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

Load-sensing circuits for servomotor systems with isolator valves

F15B 2211/6058

using two or more pumps
Definition statement

This place covers:

Using two or more main pumps to pressurise the fluid circuit.

Illustrative example of subject matter classified in this place:

media57.png

References
Informative references

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

Circuits for servomotor systems with multiple pumps

F15B 2211/20576

{Linear stepwise operation}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media35.png

{Rotary stepwise operation}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media36.png

controlling several interacting or sequentially-operating members
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media58.png

References
Informative references

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

Fluid distribution or supply devices for the control of two or more servomotors

F15B 13/06

{the position of the actuator controlling the fluid flow to the subsequent actuator}
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media59.png

References
Informative references

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

Telescopic jibs for cranes

B66C 23/701

Synchronisation of the movement of two or more servomotors
Definition statement

This place covers:

Illustrative example of subject matter classified in this place:

media60.png

References
Informative references

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

Circuits for servomotor systems for concurrent control of multiple output members, e.g. synchronisation of two or more actuators

F15B 2211/782

Controlling the movement of a plurality of actuating members to maintain parallel movement of the platen or press in fluid-driven presses

B30B 15/24

Details of servomotor systems ({F15B 1/04, F15B 1/26, F15B 3/00, F15B 7/08, F15B 11/02, F15B 11/10,} F15B 15/00 take precedence){; Valves for servomotor systems}
Definition statement

This place covers:

Components of hydraulic or pneumatic circuits such as valves and flow dividers.

Locking-valves or other detent {i.e. load-holding} devices
References
Informative references

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

Systems with load holding valves

F15B 11/003, F15B 2211/30515

Locking mechanisms associated with the actuator

F15B 15/26

Synonyms and Keywords

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

  • "over-centre valve", "locking-valve"
Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
References
Informative references

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

Multiple-way valves

F16K 11/00

Special rules of classification

Subgroups F15B 13/022 - F15B 13/029 are not complete

{Valves for interconnecting the fluid chambers of an actuator}
References
Informative references

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

Regenerative circuits

F15B 11/024

Systems with directional control valves having a separate valve for interconnecting the fluid chambers of an actuator

F15B 2211/3058

Systems with directional control valves having a regenerative position

F15B 2211/3133

Synonyms and Keywords

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

  • "valves for interconnecting the fluid chambers of an actuator" and "Regeneration valves"
{Flow-dividers; Priority valves}
References
Informative references

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

Circuits for giving priority to a particular servomotor

F15B 11/162

Flow control using flow dividers

F15B 2211/40523

Priotity valves for power steering

B62D 5/07

{Excess flow valves, e.g. for locking cylinders in case of hose burst}
Synonyms and Keywords

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

  • "excess flow valves", "Rohrbruchsicherung" and "clapet parachute"
{Check valves}
References
Informative references

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

Load holding valves

F15B 13/01

Locking valves

F15B 13/01

{Counterbalance valves}
References
Informative references

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

Servomotor systems with counterbalance valves

F15B 11/0445

Pressure control using counterbalance vavles

F15B 2211/50581

{for linearly sliding valves, e.g. spool valves}
Definition statement

This place covers:

Illustrative example of subject matter classified in this group.

media6.png

Fig. from WO2008015752

{with means or adapted for load sensing}
References
Informative references

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

Systems with load sensing

F15B 11/05, F15B 11/161, F15B 2211/3053

{with manually-operated pilot valves, e.g. joysticks}
References
Informative references

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

Arrangements of handles or pedals for cranes

B66C 13/54

Control levers for dredgers and soil shifting machines

E02F 9/2004

Similar mechanical control actuators

G05G 9/047

with electrically-controlled pilot valves
References
Informative references

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

Electrically operated main valves

F15B 13/044

operated by electrically-controlled means, e.g. solenoids, torque-motors
References
Informative references

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

Electrically controlled pilot valves

F15B 13/043

{Modular valves}
References
Informative references

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

Modular valves in general

F16K 27/003

{Data bus systems}
References
Informative references

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

Servomotor systems using data bus, e.g. CAN bus

F15B 21/085

Special measures for feedback {, e.g. by a follow-up device}
References
Informative references

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

Servomotors with follow-up action

F15B 9/00

Devices with means or adapted for load sensing

F15B 13/0416

Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
Definition statement

This place covers:

Hydraulic or pneumatic actuators with linear or non-continuous rotary output.

References
Informative references

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

Motors with continuous rotary movement

F01, F03

for mechanically converting rectilinear movement into non- rectilinear movement
References
Informative references

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

Fluid-driven safety belt tensioners

B60R 22/4628

{Actuator having both linear and rotary output, i.e. dual action actuator}
References
Informative references

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

Corresponding FI class

F15B15/06&E

Characterised by the construction of the motor unit
References
Informative references

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

Pistons, cylinders, packings

F16J

{the motor being of the slotted cylinder type}
References
Informative references

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

Locking mechanisms therefor

F15B 15/265

{the motor being of the rodless piston type, e.g. with cable, belt or chain}
References
Informative references

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

Locking mechanisms therfor

F15B 15/265

the motor being of diaphragm type
References
Informative references

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

Connection of valves to inflatable elastic bodies

B60C 29/00

Inflatable flexible elements for lifting goods

B66F 3/35

Pneumatic actuators for EGR valves

F02M 26/58

Clutches with fluid-actuated elastic clutching member

F16D 25/04

Bellows pistons

F16J 3/06

{using inflatable bodies that contract when fluid pressure is applied, e.g. pneumatic artificial muscles or McKibben-type actuators}
Definition statement

This place covers:

Illustrative example of subject matter classified in this group.

media7.png

Fig. from US4819547

References
Informative references

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

Corresponding FI class

F15B15/10&H

Synonyms and Keywords

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

  • "fluidic muscle-type actuator", "McKibben-type actuator" and "Fluidischer Muskel"
of the oscillating-vane or curved-cylinder type
References
Limiting references

This place does not cover:

Rotary motors with continuous output movement

F01C 9/002, F03C 4/00, F04C 9/002

Sealings for vane motors

F16J 15/545

{of the curved-cylinder type}
Definition statement

This place covers:

Illustrative example of subject matter classified in this group.

media8.png

Fig. from JP58163805

{in clusters, e.g. multiple cylinders in one block}
References
Informative references

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

Systems with servomotors having a plurality of working chambers

F15B 11/036

Motors with two or more independently movable working pistons

F15B 15/1409

{with two or more independently movable working pistons}
References
Informative references

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

Servomotor systems with step-by-step action

F15B 11/12

Servomotor systems with stepwise operation

F15B 11/18

{Pistons; Piston to piston rod assemblies}
References
Limiting references

This place does not cover:

Pistons per se

F16J 1/00

{Hollow piston sliding over a stationary rod inside the cylinder}
References
Informative references

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

Systems for controlling the actuator force

F15B 11/036

{Special measures for cooling or heating}
Special rules of classification

When the fluid powering the fluid-actuated device is used for cooling or for heating said device, either one of F15B 21/0423 additional information when the fluid-actuated device is cooled or F15B 21/0427 additional information when the device is heated, has to be allocated complementary to the classification in this group.

Combined units comprising both motor and pump
References
Informative references

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

Telemotors

F15B 7/00

Locking mechanisms
References
Informative references

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

Locking valves not combined with the actuator

F15B 13/01

{using positive interengagement, e.g. balls and grooves, for locking in the end positions}
Definition statement

This place covers:

Locking mechanisms using positive interengagement for locking in any distinct position (not restricted to locking in the end positions).

{Screw mechanisms attached to the piston}
Definition statement

This place covers:

This subgroup contains documents relating to locking mechanisms using screw mechanisms attached to the piston but not using friction.

{using electromagnetic radiation, e.g. radar or microwaves}
Special rules of classification

F15B 15/2846 takes precedence.

Combinations of telemotor and servomotor systems
References
Informative references

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

Telemotors

F15B 7/00

Servomotors with follow-up

F15B 9/00

Servomotors without follow-up

F15B 11/00

Parallel arrangements of independent servomotor systems
Definition statement

This place covers:

E.g. redundant systems.

media9.png

Fig. from DE1940946A1

Testing; {Calibrating; Fault detection or monitoring; Simulation or modelling of} fluid-pressure systems or apparatus not otherwise provided for
References
Informative references

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

Testing of fluid pressure systems

F15B 2211/855

Monitoring of fluid pressure systems

F15B 2211/857

Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
References
Informative references

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

Control during or prevention of an electric or electronic failure

F15B 2211/862

Control during or prevention of an hydraulic or pneumatic failure

F15B 2211/863

Control during or prevention of a human failure

F15B 2211/8643

Prevention of failures

F15B 2211/865

Detection of failures

F15B 2211/87

Control measures for coping with failures

F15B 2211/875

Safety devices in general

F16P

Safety devices for pneumatic or hydraulic control systems

F16P 3/22

{Electrical failure}
References
Informative references

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

Control during or prevention of electric or electronic failures

F15B 2211/862

{Fluid pressure supply failure}
References
Informative references

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

Fluid supply failure

F15B 2211/8633

{Leakage; Spillage; Hose burst}
References
Informative references

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

Valve or hose failure

F15B 2211/8636

{Valve failure}
References
Informative references

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

Valve or hose failure:

F15B 2211/8636

{Compensation or avoidance of ambient pressure variation}
References
Informative references

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

Systems with a pressurised main reservoir

F15B 1/265

{Reduction of noise or vibration}
References
Informative references

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

For pumps

F04B 39/0027

Servomotor systems with program control derived from a store or timing device; Control devices therefor
References
Informative references

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

Servomotor systems with electrically operated control means

F15B 21/08

Program control in washing machines

D06F 33/04

Program control in general

G05B 19/00

Special measures taken in connection with the properties of the fluid
References
Informative references

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

Using the fluid for cooling or heating a fluid-actuated device, i.e. a fluidic actuator

F15B 15/1485

Special rules of classification

When the fluid is used for cooling or heating a specific component, e.g. an electric motor, other than a fluid-actuated device, i.e. a fluidic actuator, it is classified in F15B 21/04 as inventive information and in F15B 21/0423 additional information when the fluid is used for cooling said component, or F15B 21/0427 additional information when the fluid is used for heating said component.

Controlling the temperature of the fluid
Special rules of classification

When the fluid is used for cooling or heating a specific component, e.g. an electric motor, classification in F15B 21/04 applies in accordance with the special rule of F15B 21/04.

Heating
Special rules of classification

Control of a cooling device to increase the temperature of the fluid, e.g. bypassing a cooling device for warmup, is classified in F15B 21/0427 as inventive information and also in F15B 21/0423 as additional information.

Removal or measurement of undissolved gas, e.g. de-aeration, venting or bleeding
References
Informative references

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

Preventing cavitation

F15B 21/047

Synonyms and Keywords

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

  • "deaeration" and "Entlüftung"
Compensating for variations in viscosity or temperature
References
Informative references

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

Warming up fluid systems

F15B 21/042

Preventing foaming, churning or cavitation
References
Informative references

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

Supply reservoir or sump assemblies

F15B 1/26

Control during or prevention of cavitation

F15B 2211/8609

Arrangements for compressed air preparation, e.g. comprising air driers, air condensers, filters, lubricators or pressure regulators
References
Informative references

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

For mist lubrication

F16N 7/32

For steam traps

F16T

For airconditioning

F24F

Use of special fluids, e.g. liquid metal; Special adaptations of fluid-pressure systems, or control of elements therefor, to the use of such fluids
References
Limiting references

This place does not cover:

Actuators having special fluid pressurization means

F15B 2015/208

{Use of electro- or magnetosensitive fluids, e.g. electrorheological fluid}
References
Informative references

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

Control specific to the type of fluid, e.g. specific to magnetorheological fluid

F15B 2211/885

{using a data bus, e.g. "CANBUS"}
References
Informative references

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

Modular units using data bus

F15B 13/0867

Special rules of classification

F15B 13/0867 takes precedence.

Delay devices or arrangements
References
Informative references

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

Hydraulic braking

F15B 11/076

Delay devices associated with fluid motors or actuators

F15B 15/22

Fluid oscillators or pulse generators
References
Informative references

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

Fluid oscillators used for computing or control purposes

F15C 1/22, F15C 3/16

Energy-recuperation means
References
Informative references

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

Regenerative circuits

F15B 11/024

Control measure for saving energy

F15B 2211/88

For vehicles

B60T 1/10

Systems for storing electric energy specially adapted for power networks using storage of pneumatic energy

H02J 15/20

having additional valves for interconnecting the fluid chambers of a double-acting actuator, e.g. for regeneration mode or for floating mode
References
Informative references

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

Floating position connecting the working ports and the return line

F15B 2211/3127

Regenerative position connecting the working ports or connecting the working ports to the pump, e.g. for high-speed approach stroke

F15B 2211/3133