CPC Definition - Subclass G05D

Last Updated Version: 2019.05
SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES (for continuous casting of metals B22D 11/16; valves per se F16K; sensing non-electric variables, see the relevant subclasses of G01; for regulating electric or magnetic variables G05F)
Definition statement

This place covers:

Systems for controlling or regulating non-electric variables, in particular: position, trajectory, attitude or altitude of a vehicle; position or direction of an object; thickness or size of materials; flow rate; level; quantity ratio; linear or angular speed; force or stress; fluid pressure; torque or mechanical power; vibrations; chemical variables; humidity; temperature; viscosity; and illumination.

"controlling" means influencing a variable in any way, e.g. changing its direction or its value (including changing it to or from zero), maintaining it constant, limiting its range of variation.

"regulation" means maintaining a variable automatically at a desired value or within a desired range of values. The desired value or range may be fixed, or manually varied, or may vary with time according to a predeterminated "programme" or according to variation of another variable. Regulation is a form of control.

Merely acting on a variable for the purpose of influencing the state of a system (e.g. acting on the fuel flow rate in an engine for achieving a certain speed), where the value of the variable itself remains irrelevant, should a priori not be considered as controlling or regulating said variable.

References
Limiting references

This place does not cover:

Features of general applicability to regulating systems, e.g. anti-hunting arrangements

G05B

Regulating electric or magnetic variables

G05F

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:

Milking machines

A01J 5/007

Welding parameters

B23K 9/095

Copying

B23Q 35/00

Grinding or polishing

B24B 17/00, B24B 49/00

Abrasive blasts

B24C 7/00

Dispensing beverages on draught

B67D 1/12

Electrographic, electrophotographic or magnetographic processes

G03G 21/20

Dynamo-electric motors or generators

H02P 5/00 - H02P 9/00

Special rules of classification

Control systems specially adapted for particular apparatuses, machines or processes are classified in the subclasses for the apparatus, machine or process, provided that there is specific provision for control or regulation relevant to the special adaptation, either at a detailed level, (e.g. A21B 1/40: "for regulating temperature in bakers' ovens") or at a general level, (e.g. B23K 9/095: "for automatic control of welding parameters in arc welding"). Controlling aspects of space crafts are excluded from the G05D. They should be classified in B64G 1/244. Otherwise, classification is made in the most appropriate place in this subclass.

Places where there is specific provision of the kind referred to above at a detailed level have been listed under the main groups of this subclass (see "References relevant to classification in this subclass"). Where the provision is at a general level (e.g. of a kind appropriate to more than one of the main groups specified in the lists, or to main groups G05D 27/00 or G05D 29/00), the places are listed under this subclass.

A document that can be applied to two or more applications is not specific for any of them and has to be classified in G05D (for instance a thermostat for heating or air conditioning).

A formulation of the kind "regulator for the application X" should a priori not be considered as specific to said application.

Usually, the subdivisions of the regulation classes in the field of the application are less precise than in G05D, therefore giving a class in G05D may be useful for search.

When in a document there is mention of several controlled variables, one should try to visualize the block scheme of the regulation. The document is then to be classified in the group of the variable controlled in the outer control loop. In case the regulation in one of the other control loops is of particular interest, it should also be classified in the group(s) of the variable(s) concerned.

Note that the above is without prejudice of the limiting references contained in the titles of the different groups and subgroups in this subclass.

In the main groups of this subclass, remarks found under "Further details of subgroups" are not meant to replace the definitions in the titles, but either give further information about the definitions or mention particular types of documents to be classified in the subgroups or to be excluded from them. In case no remark is made on a given subgroup, the title is considered to be self-explanatory.

In G05D, the hierarchy in classification is generally done according:

- to the physical variable

- Then to the nature of the auxiliary power used, with the following possibilities, not used for all the variables:

  • without auxiliary power (purely mechanical regulation)
  • with auxiliary non-electric power (e.g. pneumatic or hydraulic)
  • characterised by the use of electric means
  • with combination of electric and non-electric auxiliary power

- Then, to the type of sensor used.

Glossary of terms

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

Systems

includes self-contained devices such as speed governors, pressure regulators

Control of position, course or altitude of land, water, air, or space vehicles, e.g. automatic pilot (radio navigation systems or analogous systems using other waves G01S)
Definition statement

This place covers:

Control of position, course or altitude of land, water, air, or space vehicles, e.g. automatic pilot

Further details of subgroups

This subgroup covers control systems where the trajectory of an aircraft or satellite is optimized.

Redundant control systems in general are classified only in G05B 9/03.

This subgroup covers control of an aircraft while on the ground, i.e. while accelerating before taking-off, braking after touching down or taxiing.

G05D 1/02 and subgroups

This subgroup covers control systems where the position determination or the position evolution takes place on a two-dimensional space. If the nature of the vehicle is specified, then it is classified in the corresponding subgroup.

G05D 1/0202 and subgroup

This subgroup covers two-dimensional navigation of an aircraft while in flight.

G05D 1/021 and subgroups

This subgroup covers control systems to define a trajectory for a land vehicle, and to take suitable actions to make the vehicle follow said trajectory.

Aspects of navigation systems that are important per se should also be classified in the relevant groups of G01C.

Aspects of radio, sonar or lidar navigation systems that are important per se should also be classified in the relevant groups of G01S.

Aspects of navigation systems for traffic purposes that are important per se should also be classified in the relevant groups of G08G.

This subgroup also covers control systems using barcode readers for positioning.

This subgroup also covers control systems using RFID tags for positioning.

This subgroup covers control systems where one of the vehicles sends orders to the others.

Relationships with other classification places

Subclass G01C covers navigation in general, i.e. determining the position and course of land vehicles, ships, aircraft, and space vehicles.

Subclass G01S covers radio, sonar or lidar navigation systems, i.e. navigation by use of radio, acoustic or optical waves, or analogue arrangements using other electromagnetic waves.

Subclass G08G covers navigation systems for traffic control purposes, i.e. systems in which the navigation is not performed autonomously by or in the vehicle, but where the vehicles are guided by instructions transmitted to them.

References
Limiting references

This place does not cover:

Radio navigation systems or analogous systems using other waves

G01S

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:

Agricultural machines or implements

A01B 69/00

Toy vehicles

A63H 17/36

Air-cushion vehicles

B60V 1/11

Driver Assistance Systems for road vehicles

B60W 30/00

Steering controls of motor vehicles or trailers, i.e. means for initiating a change of direction

B62D 1/00

Arrangements for automatically controlling the steering depending on driving conditions

B62D 6/00

Active steering aids

B62D 15/025

Chassis of endless-tracked vehicles

B62D 55/116

Marine steering; control of waterborne vessels

B63H 25/00

Controlling aircraft

B64C 13/00 - B64C 15/00

Controlling attitude or direction of aircraft ejector seats

B64D 25/10

Cosmonautic vehicles

B64G 1/24

Self-propelled missiles

F41G 7/00

Guided missiles

F42B 15/01

Marine torpedoes

F42B 19/01

Informative references

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

Linear or angular position control of an object not being a vehicle

G05D 3/00

Control of linear or angular speed or of acceleration

G05D 13/00

Steering applicable only to other than landborne vehicles, e.g. three-dimensional steering applicable to both aircraft and submarines

B60K

Rail vehicles

B61

Construction or disposition of steering means on land vehicles

B62

on waterborne vessels

B63

Manual or automatic control of aircraft, e.g. using automatic pilot or radiated signal

B64C

Altitude control by jet reaction

B64C 15/00

Aircraft capable of landing or taking-off vertically

B64C 29/00

Flying bombs

B64C 2201/121

Unmanned aerial vehicles characterized by flight control

B64C 2201/14

Unmanned aerial vehicles characterized by landing method

B64C 2201/18

Aircraft carrier installations

B64F

Altimeters

G01C 5/005

Navigation, i.e. determining the position and course of land vehicles, ships, aircraft, and space vehicles

G01C 21/00

Measuring distance traversed on the ground by vehicles, e.g. using odometers

G01C 22/00

Flight directors

G01C 23/005

Displays for beacons e.g. LORAN, VOR

G01S 1/047

Using amplitude comparison of signals transmitted simultaneously from aerials or aerials systems having differently-oriented overlapping directivity-characteristics

G01S 1/14

LORAN systems

G01S 1/24

LORAC or TORAN systems

G01S 1/304

TACAN systems

G01S 1/48

VOR systems

G01S 1/50

Position-fixing by co-ordinating a plurality of determinations of direction or position lines

G01S 5/00

Determining distance or velocity using waves and not using reflection or reradiation of waves

G01S 11/00

Radar systems specially designed for missile homing, autodirectors

G01S 13/883

Radar systems specially designed for traffic control

G01S 13/91

Radar systems specially designed for anti-collision purposes

G01S 13/93

Radar systems specially designed for terrain avoidance

G01S 13/94

Sonar systems specially designed for anti-collision purposes

G01S 15/93

Lidar systems specially designed for anti-collision purposes

G01S 17/93

Traffic control systems for road vehicles

G08G 1/00

Anti-collision traffic control systems

G08G 1/16

Monitoring the location of fleet of vehicles in traffic control systems

G08G 1/20

Modification of a flight plan

G08G 5/0039

Terrain avoidance systems

G08G 5/0086

Systems for monitoring atmospheric conditions

G08G 5/0091

Traffic collision avoidance systems

G08G 5/04

Special rules of classification

This main group concerns only vehicles.

Documents are classified here in case:

  • the stability of the vehicle is obtained or improved by the regulation;
  • the sensors are piloting-specific: (i) to follow a predetermined trajectory; (ii) there is an interaction between the position determination and the goal to be achieved (for example there is a camera to recognize the environment and a processor to determine the trajectory);
  • the security of the piloting or the control of the piloting is achieved by electronic means;
  • of remote control;
  • of piloting-specific optimization; or
  • of interactions between vehicles.

Within this main group, the possible applications of a land vehicle are also classified in G05D 2201/02.

Within G05D 1/021 and its subgroups, an invention is classified in the subgroups of all the sensors that are essential for the invention. Sensors that are either optional or not directly involved in the invention are classified as additional information.

Target-seeking control
Definition statement

This place covers:

Control of vehicle position to acquire, maintain or re-acquire a target, e.g. a person or another vehicle, for tracking, following or interdiction purposes.

References
Informative references

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

Direction control systems for self-propelled missiles

F41G 7/00

Target detection

G06K 2209/21

Analysis of motion

G06T 7/20

Control of position or direction (G05D 1/00 takes precedence)
References
Limiting references

This place does not cover:

Position control of a vehicle

G05D 1/00

Control of linear or angular speed or of acceleration

G05D 13/00

Control of machine tools

B23Q

Programme-controlled manipulators

B25J 9/00

Programme-control systems

G05B 19/00

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:

Footwear manufacture

A43D 119/00

Tool carriers in forging or pressing

B21K 31/00

Pattern-controlled boring or drilling tools

B23B 39/26

Planing or slotting machines controlled by copying device

B23D 1/30, B23D 3/06, B23D 5/04

Electrode to workpiece spacing in electric discharge and electrochemical machining

B23H 7/18

Workpiece in laser welding or cutting

B23K 26/02

Workpiece in welding

B23K 37/04

Molten metal in welding

B23K 37/06

Spindles in machine tools

B23Q 5/20

Tool or work position in machine tools

B23Q 15/00, B23Q 16/00

Tools controlled by pattern or master model

B23Q 35/00

Grinding controlled by patterns, drawings, magnetic tape or the like

B24B 17/00

Starting position in grinding

B24B 47/22

Actuating members in presses

B30B 15/24

Chassis of tracked vehicles

B62D 55/116

Web-advancing mechanisms

B65H 23/18

Dippers or buckets in dredgers

E02F 3/43

Fluid-pressure servomotors with follow-up action

F15B 9/00

Tracking of solar heat collectors

F24S 50/20

Photomechanical production of patterned or textured surfaces

G03F 9/00

Rotating heads in information storage systems

G11B 5/588

Movement of control elements in nuclear reactors

G21C 7/12

Control of dimensions of material
Definition statement

This place covers:

Control of thickness or size of material

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:

Tobacco cutting

A24B 7/14

Thickness of coating of fluent material on surface

B05C 11/02

Thickness, width, diameter or other transverse dimensions of the products of metal-rolling mills

B21B 37/16

Dimension of glass ribbon

C03B 18/04

Thickness of layer in paper making

D21F 7/06

Control of flow (level control G05D 9/00; ratio control G05D 11/00; weighing apparatus G01G)
Definition statement

This place covers:

Control of flow of liquids, gases, particulate matter and other fluent materials by action on throttling means and/or flow sources.

Further details of subgroups:

This subgroup covers valves where the flexible member itself, e.g. a membrane, acts on the valve seat.

This subgroup covers for example flexible members having the form of a torus.

This subgroup covers valves with a piston having one extreme facing the inlet chamber and an opposite extreme facing the outlet chamber.

These subgroups cover valves in which at least part of the piston has the form of a cylindrical sleeve in contact with and sliding over a fixed or moving stem. They also cover valves in which the control chamber comprising the biasing member is surrounded by the controlled fluid

This subgroup covers valves using calibrated orifices for achieving a constant flow.

These subgroups cover systems where the target flow is defined in dependence on a specific parameter, e.g. the speed of a vehicle.

References
Limiting references

This place does not cover:

Level control

G05D 9/00

Ratio control

G05D 11/00

Weighing apparatus

G01G

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:

Air in hair drying helmets

A45D 20/26

Flow of media to the human body

A61M 5/168

Gases or vapour in electrostatic separators

B03C 3/36

Fluent material in coating devices

B05C 11/10

Dispensing beverages on draught

B67D 1/12

Transferring liquids

B67D 7/28

Gas purifiers

C10K 1/28

Flushing boreholes

E21B 21/08

Obtaining liquids from wells

E21B 43/12

Flow in non-positive displacement machines or systems

F01D 17/00

Lubrication arrangements

F01M 1/16

Coolant flow in cooling devices

F01P 7/00

Gas-turbine working fluid

F02C 9/16, F02C 9/50

Throttle passages in pipes

F16L 55/027

Air-flow or supply of heating or cooling fluids in air treatment arrangements

F24F 11/00

Air or gas flow in dryers

F26B 21/12

Continuous flow weighing apparatus

G01G 11/08

Coolant in nuclear power plant

G21D 3/14

Informative references

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

Of media to the human body

A61M 5/168

Special rules of classification

Within this subgroup, an invention is classified in the last appropriate place.

Level control, e.g. controlling quantity of material stored in vessel (controlling level of liquid-pool electrode in electric discharge tubes and lamps H01J 1/10, H01J 13/14)
Definition statement

This place covers:

Control of quantity of liquids or particulate matter in a vessel by action on the input and/or the output flow.

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:

Liquid level in sedimentation arrangements

B01D 21/34

Ink level in printing, manifolding or duplicating arrangements

B41L 27/04

Feed water for boilers

F22D 5/00

Liquid pool electrodes in electric discharge tubes or lamps

H01J 1/10, H01J 13/14

Ratio control (control of chemical or physico-chemical variables, e.g. pH-value G05D 21/00 ; humidity control G05D 22/00 ; control of viscosity G05D 24/00 ; proportioning the ingredients for mixing clay or cement with other substances B28C 7/00)
Definition statement

This place covers:

Control of the relative ratio of flow rate or of volume of two or more fluent materials by action on throttling means and/or flow sources.

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:

Density in sedimentation arrangements

B01D 21/32

Mixers

B01F 15/04

Abrasive blasts

B24C 7/00

Mixtures of clays or cements

B28C 7/00

Bulk material conveyors

B65G 53/66

Flow ratio in jet-propulsion plants

F02K 3/075

Further details of subgroups:

This subgroup also covers systems using interconnected pistons

This subgroup covers systems comprising venturi aspirators.

This subgroup covers systems where the motor of the pump acting on the feeding of a fluid is operated by another fluid.

Subgroups G05D 11/001 - G05D 11/008 are used in preference to G05D 11/03, also for flow ratio control systems without auxiliary power.

Systems aiming at regulating a temperature by mixing hot and cold water are only classified in G05D 23/13 and subgroups.

Control of linear speed; Control of angular speed; Control of acceleration or deceleration, e.g. of a prime mover (synchronising telegraph receiver and transmitter H04L 7/00)
References
Limiting references

This place does not cover:

Arrangements for synchronising receiver with transmitter

H04L 7/00

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:

Drum speed in metal drawing

B21C 1/12

Cutting velocity of tool or work

B23Q 15/00

Ram speed in presses

B30B 15/20

Setting or limiting speed of vehicles

B60K 31/00

Electrically-propelled vehicles

B60L 15/00

Road vehicle cruise control

B60W 30/00

Cruising speed of aircraft

B64D 31/08

Feed rate in manufacture of artificial filaments, threads, fibres, bristles or ribbons

D01D 1/09

Carding machines

D01G 15/36

Warping, beaming or leasing machines

D02H 13/14

Cyclically varying speed of looms

D03D 51/16

Speed of fluid carrier in chemical analysis

G01N 30/32

Record carriers or heads for such carriers in information storage systems

G11B 15/46, G11B 19/28

Control of mechanical force or stress; Control of mechanical pressure
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:

Portable percussive tools

B25D 9/26

Ram pressure in presses

B30B 15/22

Tension in webs, tapes, filamentary material

B65H 23/00, B65H 59/00

Tension in filamentary material

B65H 59/00

Rope, cable or chain tension

B66D 1/50

Tension in looms

D03D 49/04

Tension in sewing machines

D05B 47/04

Pressure in paper-making machines

D21F 3/06

Drying fabrics

F26B 13/12

Pressure in dryers

F26B 21/10

Record carrier tension in information storage arrangements

G11B 15/43

Control of fluid pressure
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:

Tyre pressure

B60C 23/00

Air within diving suit

B63C 11/08

Aircraft air-pressure

B64D 13/00

Bulk material conveyors

B65G 53/66

Manufacture of artificial filaments, threads, fibres, bristles or ribbons

D01D 1/09

Flushing boreholes

E21B 21/08

Lubrication arrangements

F01M 1/16

Pressure of fluid carrier in chemical analysis

G01N 30/32

Pressure in electric discharge tubes or lamps

H01J 7/14

Pressure in electric incandescent lamps

H01K 1/52

Informative references

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

Valves per se

F16K

Control of pressure in electric discharge tubes or lamps

H01J 7/14

Control of pressure in electric incandescent lamps

H01K 1/52

Special rules of classification

These groups describing functional aspects of the invention are generally used in combination with groups G05D 16/04 - G05D 16/2097 describing structural aspects of the valves.

This group covers valves controlling a difference between two systems pressures, excluding the following cases:

  • When one of the pressures is the ambient (atmospheric) pressure or any other uncontrolled pressure that is external to the system; in this case only the structural aspects of the valve are classified in groups G05D 16/04G05D 16/2097.
  • When the controlled pressures are across a fixed or adjustable restriction for the purpose of flow regulation, in which case the document should be classified in G05D 7/00; and
  • When one of the pressures is a reference pressure generated by a pilot valve or any other means for the purpose of keeping the other pressure at a difference to said reference pressure, in which case the document should be classified either in G05D 16/14 or in G05D 16/2093.

These groups are used in combination with groups G05D 16/06G05D 16/12 describing one or more of the valves.

{with two or more controllers mounted in series}
Definition statement

This place covers:

  • Valves in a series, where the output of one valve is the input of another one.
{with two or more controllers mounted in parallel}
Definition statement

This place covers:

  • Valves having their inputs and/or outputs connected together.
the sensing element being a piston or plunger
Definition statement

This place covers:

  • Valves comprising a piston or plunger, which reacts to fluid pressure in contact therewith.
{the sensing element placed between the inlet and outlet (multiple-way valve G05D 16/101)}
Definition statement

This place covers:

  • Valves comprising a piston having one extreme facing the inlet chamber and an opposite extreme facing the outlet chamber, for example:

media1.png

Figure 1. A piston 50 having one extreme 50a facing the inlet 30 and an opposite extreme facing the outlet chamber 78.

References
Limiting references

This place does not cover:

Multiple-way valve

G05D 16/101

{Sleeve-like sensing elements; Sensing elements surrounded by the flow path}
Definition statement

This place covers:

  • Valves in which at least part of the piston has the form of a cylindrical sleeve in contact with and sliding over a fixed or moving stem.
  • Valves in which the control chamber comprising the biasing member is surrounded by the controlled fluid, for example:

media2.png

Figure 1. A part 30 of the piston 23 has the form of a cylindrical sleeve in contact with and sliding over a fixed stem 29. Furthermore, the control chamber 25a comprising the biasing member 37 is surrounded by the controlled fluid.

{with a spring-loaded piston in combination with a spring-loaded slideable obturator that move together over range of motion during normal operation}
Definition statement

This place covers:

  • Valves having a detached obturator that is biased against the sensing piston so that they move together over the range of motion during normal operations, for example:

media3.png

Figure 1. A detached obturator 11 is biased by the auxiliary spring 12 against the sensing piston 14 so that they move together over the range of motion during normal operations.

{with two or more pistons acting as a single pressure controller that move together over range of motion during normal operations (controllers mounted in series G05D 16/0402, controller mounted in parallel G05D 16/0404)}
Definition statement

This place covers:

  • Valves comprising two or more pistons that move independently of each other over the range of motion during normal operation, at least one of them being the sensing element.
References
Limiting references

This place does not cover:

Control of fluid pressure without auxiliary power with two or more controllers mounted in series

G05D 16/0402

Control of fluid pressure without auxiliary power with two or more controllers mounted in parallel

G05D 16/0404

with auxiliary non-electric power
Definition statement

This place covers:

  • Valves in which the controlled pressure is compared to a reference fluid pressure generated by means of an auxiliary pilot valve or any other means.
derived from the controlled fluid
Special rules of classification

This group may be used in combination with groups G05D 16/06G05D 16/12 describing structural details of the auxiliary pilot valve.

{with direct action of electric energy on controlling means (combination of electric and non-electric auxiliary G05D 16/2093)}
Definition statement

This place covers:

  • Electric energy acting on the main valve, and
  • Electric energy acting on the control element of the pump
References
Limiting references

This place does not cover:

With combination of electric and non-electric auxiliary power

G05D 16/2093

{using throttling means as controlling means}
Definition statement

This place covers:

  • Systems controlling the pressure using the electromagnetic valves.
Special rules of classification

Electromagnetic valves allowing only on/off operation are only classified in this group.

{actuated by a proportional solenoid (throttling means G05D 16/2024)}
Definition statement

This place covers:

  • Electromagnetic valves generating an intermediate closing force that is proportional to the current supplied.
References
Limiting references

This place does not cover:

The throttling means being a multiple-way valve

G05D 16/2024

{with a plurality of throttling means}
Special rules of classification

This group may be used in combination - with groups G05D 16/202 - G05D 16/2024 to describe one or more of the valves.

{without direct action of electric energy on the controlling means (combination of electric and non-electric auxiliary G05D 16/2093)}
Definition statement

This place covers:

  • Valves where the electric energy is used for an auxiliary function of an otherwise purely mechanical regulator, e.g. adjusting the set point.
References
Limiting references

This place does not cover:

With combination of electric and non-electric auxiliary power

G05D 16/2093

{with combination of electric and non-electric auxiliary power}
Definition statement

This place covers:

  • Valves in which the controller pressure is compared to a reference fluid pressure generated by means of an electromagnetic pilot valve or any other means.
Special rules of classification

This group may be used in combination with subgroups G05D 16/202 - G05D 16/208 describing structural details of the auxiliary pilot valve.

Control of torque; Control of mechanical power
Definition statement

This place covers:

Regulation of the torque of tightening tools, control of the torque or power of electric motors, combustion engines and the like when the control is not specific of the particular drive.

References
Limiting references

This place does not cover:

Torque limiters in tools

B25B 23/14

Propulsion units in vehicles

B60K

Control of combustion engines

F02D

Control of electric motors

H02P

Control of mechanical oscillations, e.g. of amplitude, of frequency, of phase (generating or transmitting mechanical vibrations B06B ; control of electric motors H02P)
Definition statement

This place covers:

Control of mechanical oscillations or vibrations in machines or structures, either by generating oscillations, or by damping oscillations, other than suppression of vibrations.

References
Limiting references

This place does not cover:

Musical instruments; acoustics

G10

Loudspeakers or like acoustic electromechanical transducers

H04R

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:

Portable percussion tools

B25D 9/26

Jigging conveyors

B65G 27/32

Suppression of vibrations in systems

F16F 15/002

Informative references

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

Generating or transmitting mechanical vibrations

B06B

Control of electric motors

H02P

Control of chemical or physico-chemical variables, e.g. pH value
Definition statement

This place covers:

Regulation of chemical composition, concentration, pH or the like in a chemical process when the regulation is not specific of the particular process.

References
Limiting references

This place does not cover:

Ratio control

G05D 11/00

Humidity control

G05D 22/00

Control of viscosity

G05D 24/00

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:

Density in sedimentation arrangements

B01D 21/32

Treating gases or vapours

B01D 53/30

Composition of fluid carrier in chemical analysis

G01N 30/34

Informative references

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

Physical or chemical processes in general

B01J

Treatment of water

C02F

Control of humidity (of tobacco products A24B 9/00 ; air conditioning F24F)
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:

Watering gardens, fields, sports grounds or the like

A01G 25/16

Poultry incubators

A01K 41/04

Tobacco products

A24B 9/00

Moistening in air treating devices of vehicles

B60H 3/02

Air conditioning

F24F 11/00

Dryers

F26B 21/08

Control of temperature (automatic switching arrangements for electric heating apparatus H05B 1/02)
Definition statement

This place covers:

Control of temperature

Further details of subgroups:

These subgroups cover valves controlling the flow of a fluid as a function of the temperature of said fluid.

These subgroups cover valves controlling the flow of a fluid as a function of the temperature of an external sensor, e.g. thermostat for radiator.

G05D 23/024 and subgroups

These subgroups cover memory shape alloys working as a sensing element.

This subgroup covers systems where the fusing of an element irreversibly releases a cooling fluid.

This subgroup covers valves controlling the flow of fuel to a burner as a function of the temperature of a controlled space.

This subgroup covers valves distributing the flow of a fluid among two conduits as a function of the temperature of said fluid, e.g. refrigerating systems.

This subgroup covers not only valves where the flow is regulated, but also where it is just set by the user.

G05D 23/185 and subgroups

These subgroups cover valves similar to the corresponding subgroups in G05D 23/01, but further comprising the use of auxiliary pneumatic or hydraulic energy.

G05D 23/19 and subgroups

In G05D 23/19 documents are classified in G05D 23/20, G05D 23/22, G05D 23/24, G05D 23/26, G05D 23/27, or G05D 23/275 and their subgroups according to the nature of the main temperature sensor used. Additionally, documents are also classified in the CPC subgroups G05D 23/1902 - G05D 23/1951 relating to control features, if one or more them apply. In case the nature of the temperature sensing element is not mentioned or is irrelevant for the invention, documents are classified only in G05D 23/19 or in one of more subgroups G05D 23/1902 - G05D 23/1951.

G05D 23/20 and subgroups

This covers inventions where the sensing element has a variation of electric or magnetic properties other than defined in G05D 23/22, G05D 23/24 or G05D 23/26, e.g. a semiconductor, an ionized gas or a capacitor.

This subgroup covers inventions relating to the input means of the reference value.

This subgroup covers systems where a temperature profile is defined as a function of time.

This subgroup covers systems where the control action is a continuous function of the measured error.

This subgroup covers systems delivering a series of pulses having a frequency that is a continuous function of the measured error.

This subgroup covers systems using Peltier effect devices.

This subgroup covers systems where the actuator consists of a heat expanding element being heated electrically in order to act on a valve.

This subgroup covers control systems for storage heaters.

This subgroup covers systems using solar energy.

This subgroup covers systems measuring the temperature of the controlled space and of another space in thermal relationship with it, e.g. outdoors.

This subgroup covers systems where one sensor is used for control after the other, e.g. measuring the input flow temperature of a heating system and later switching to measuring the output flow temperature.

References
Limiting references

This place does not cover:

Automatic switching arrangements for electric heating apparatus

H05B 1/02

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:

Bakers' ovens

A21B 1/40

Hair curlers

A45D 6/20

Metal extruding

B21C 31/00

Tyre temperature

B60C 23/00

Cosmonautic vehicles

B64G 1/50

Float baths in glass making

C03B 18/18, C03B 18/22

Manufacture of artificial filaments, threads, fibres, bristles or ribbons

D01D 1/09

Knitting machines

D04B 35/30

Hand irons

D06F 75/26

Paper-making machines

D21F 5/06

Lubricant in lubrication arrangements

F01M 5/00

Arrangements for supplying oil or unspecified lubricant from a reservoir

F16N 7/08

Steam superheat

F22G 5/00

Dryers

F26B 21/10

Temperature of fluid carrier in chemical analysis

G01N 30/30

Electric storage cells

H01M 10/60

Automatic switching arrangements for electric heating apparatus

H05B 1/02

Dielectric, induction or microwave heating

H05B 6/06, H05B 6/50, H05B 6/68

Anode of X-ray tube

H05G 1/36

Informative references

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

Control of central heating systems

F24D 19/10

Control of air-humidification systems

F24F 11/0008

Thermal management of data-processing equipment

G06F 1/206

Controlling induction heating

H05B 6/06

Regulating temperature of anode of X-ray tube

H05G 1/36

Cooling arrangement of electrical apparatus

H05K 7/20

Special rules of classification

Within subgroups G05D 23/01 - G05D 23/32, an invention is classified in the last appropriate place in the absence of an indication of the contrary.

Control of light, e.g. intensity, colour, phase (mechanically operable parts of lighting devices for the control of light F21V ; optical devices or arrangements using movable or deformable elements for controlling light independent of the light source G02B 26/00 ; devices or arrangements, the optical operation of which is modified by changing the optical properties of the medium of the devices or arrangements for the control of light, circuit arrangements specially adapted therefor, control of light by electro-magnetic waves, electrons or other elementary particles G02F 1/00 ; circuit arrangements for controlling light sources H01S 3/10, H05B 33/08, H05B 35/00 - H05B 43/00)
Definition statement

This place covers:

Regulation of intensity, colour or phase of light other than by acting on the light sources.

References
Limiting references

This place does not cover:

Vehicle lighting

B60Q

Operating screening devices

E06B 9/68

Mechanically operable parts of lighting devices for the control of light

F21V

Optical devices or arrangements using movable or deformable elements for controlling light independent of the light source

G02B 26/00

Devices or arrangements, the optical operation of which is modified by changing the optical properties of the medium of the devices or arrangements for the control of light, circuit arrangements specially adapted therefor, control of light by electro-magnetic waves, electrons or other elementary particles

G02F 1/00

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:

Photographic composing machines

B41B 21/08

Lasers and other light sources

H01S 3/10, H05B 33/08, H05B 35/00 - H05B 43/00

Simultaneous control of variables covered by two or more of the preceding main groups
Special rules of classification

If there is a double regulation (two independent set points for two corresponding controlled variables, e.g. temperature and humidity, when there are interactions in the control loops), the document is also classified in this group. Thus, this group should be assigned in addition to the groups corresponding to the two or more controlled variables.

Simultaneous control of electric and non-electric variables
Special rules of classification

If there is a double regulation (two independent set points for two corresponding controlled variables, when there are interactions in the control loops), the document is also classified in this group. Thus, this group should be assigned in addition to the groups corresponding to the two or more controlled variables.

Subject matter not provided for in other groups of this subclass
Special rules of classification

This group is not being used.