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COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
Definition statement
This subclass/group covers:

Systems of clutches or couplings for transmitting rotation used within a mechanism of general utility.

Combinations of clutches and brakes used within a mechanism of general utility.

Combinations couplings for transmitting rotation from one element to another and brakes used in conjunction with each other in a mechanism of general utility.

Combinations of couplings for transmitting rotation from one element to another and a clutch used in conjunction with each other in a mechanism of general utility.

Couplings per se for transmitting rotation of the following types:

  • Rigid couplings (e.g. for connecting two coaxial shafts or for attaching a member on a shaft);
  • Yielding couplings (e.g. Oldham couplings, Hooke's joints, cardan joints);
  • Impulse couplings;
  • Slip couplings;
  • Safety couplings;
  • Hydrostatic couplings;
  • Hydrokinetic couplings.

Clutches per se of the following types:

  • Friction clutches (e.g. disc clutches, multiple disc clutches);
  • Freewheel clutches;
  • Hydrostatic clutches;
  • Hydrokinetic clutches;
  • Visco clutches;
  • Internally controlled automatic clutches, e.g. centrifugal clutches, torque limiting clutches;
  • External control of clutches.

Clutch components or special features related to clutches:

  • Actuation mechanisms;
  • Clutch slack adjusters;
  • Clutch cooling devices.

Brakes per se of the following types:

  • Liquid- or air-resistant brakes, e.g. Föttinger brakes, retarder;
  • Self-acting brakes;
  • Drum brakes;
  • Disc brakes.

Brake components or special features related to brakes:

  • Brake shoes, pads or bands;
  • Brake discs or drums;
  • Actuation mechanisms;
  • Brake slack adjusters;
  • Brake cooling devices;
  • Brake monitoring, e.g. wear indication.

Friction linings in general:

  • Composition of linings;
  • Attachment of linings.

Other types of couplings for transmitting rotation, clutches or brakes not provided for in another subclasses of the IPC.

Relationship between large subject matter areas

F16D is a general function-orientated place.

Application-orientated places for this subject matter are provided elsewhere in the classification – see below.

References relevant to classification in this subclass
This subclass/group does not cover:
Electrodynamic brake systems for vehicles in general
Vehicle brake control systems
Conjoint control of vehicle sub-units of different type or different function, e.g. when at least one sub-unit is a clutch or a brake
Fluid gearings
Combinations of fluid gearings with clutches or couplings
Combinations of mechanical gearings with fluid clutches
Differential gearings, e.g. with freewheels or other clutches
Dynamo-electric brakes or clutches, e.g. of the Eddy-current hysteresis type
Clutches or holding devices using electrostatic attraction, e.g. using Johnson-Rahbek effect
Informative references
Attention is drawn to the following places, which may be of interest for search:

Couplings

Couplings for metal-rolling mills
Attachment of wheels to axles for railway carriages
Attachment of marine propellers on shafts
Couplings for drilling rods

Clutches

Clutches of harvesters or mowers for grass, cereals or other crops
Clutches in dental machines for boring or cutting
Clutches specially adapted for presses
Arrangement or location of clutches in vehicles
Arrangement or mounting of control devices for main transmission clutches in vehicles
Cycle brakes controlled by back-pedalling
Details of rotary fluid gearing of the hydrokinetic type
Combinations of mechanical gearings with fluid clutches
Clutches for apparatus for transmitting or receiving coded digital information

Brakes

Brakes of harvesters or mowers for grass, cereals or other crops
Brakes for threshing machines
Brakes for swings
Brakes specially adapted for presses
Braking devices for ribbon-feed devices in selective printing mechanisms
Electrodynamic brake systems for vehicles in general
Vehicle brake control systems
Brakes peculiar to rail vehicles
Braking mechanisms for hand carts
Braking mechanisms for children's carriages or perambulators
Braking mechanisms for animal-drawn vehicles
Cycle brakes
Braking devices for lifting or hoisting gear
Brakes for electric motors, generators, or dynamo-electric converters

Couplings, clutches and/or brakes

Conjoint control of vehicle sub-units of different type or different function, e.g. when at least one sub-unit is a clutch or a brake
Fluid gearings
Combinations of fluid gearings with clutches or couplings
Special rules of classification within this subclass

For this subclass reference is made to the corresponding Indexing Code scheme: F16D.

For clutches and couplings in F16D 1/00 to F16D 48/00 only: see F16D 2300/00, F16D 1/00 to F16D 48/00 and F16D 2500/00.

Special rules of classification for brakes, i.e. for groups F16D 48/00 to F16D 71/04:

Classification rules in groups F16D 48/00 to F16D 71/04 for brakes:

The IPC-guide refers to "invention information".This definition is not followed, since "the addition to the prior art" of most documents is not always clear. In subclass F16D the criteria for classification derive from the main rule that

al relevant technical information of a document is classified to allow efficient retrieval. Therefore multi-aspect classification is used and most documents should preferably have two or more classification symbols. One symbol to describe the general configuration or overall construction and one or more further symbols to identify additional features should be assigned.

To avoid duplication of entries for the same subject matter, most of the existing subgroups relating to the type of operation force (e.g. hydraulic) are no longer used for classification. Instead the codes relating to brake actuation in groups F16D121/00 to F16D131/00 are given to each document.

Examples:

A hydraulically actuated band brake previously classified in IPC group F16D 49/12 is classified according the rules in F16D 49/08 and F16D121/04.

A hydraulically and magnetically actuated band brake also classified in IPC group F16D 49/12 is classified according the rules in F16D 49/08, F16D121/04, F16D121/20 and F16D123/00.

Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Actuator
A component of a mechanism that causes movement of a motion-conveying component or motion-inhibiting component but does not itself directly convey or inhibit motion.
Brake
A mechanism with at least one component that is moved by an actuator to selectively or automatically engage or stop a member with respect to a stationary part.
Clutch
A mechanism with at least two relatively movable components that are selectively or automatically engaged with each other by control means, e.g. an actuator, to transmit mechanical power or convey motion from a first member to a second member or disengaged by control means to stop transmitting mechanical power or conveying motion.
Coupling for transmitting rotation
A mechanism that transmits torque or conveys rotary motion from a first shaft to a second shaft or other rotating member and that either does not include relatively moving components or, if it has relatively moving components, the components move without the use of control means.
Synonyms and Keywords

In patent documents the following abbreviations are often used:

Slack adjuster
Wear compensation mechanism, automatic adjuster, automatically adjusting device, automatic adjustment device, self-adjustment device
Freewheel clutch
One-way clutch
Couplings for rigidly connecting two coaxial shafts or other movable machine elements ( attachment of wheels to axles for railway carriages B60B ; for attachment of cranks to their shafts F16C 3/10)
References relevant to classification in this group
This subclass/group does not cover:
Attachment of cranks to their shafts
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Rigidly
"rigidly" means that there is no play or clearance intended in the connection (DE:spiel, FR:jeu).
non-disconnectable, e.g. involving gluing, welding or the like
Definition statement
This subclass/group covers:

Used for adhesive connection or welding, but not limited thereto. Rivets are also non-disconnectable therefore this type of connection would also be classified here. But bolts are usually disconnectable and would be classified rather in F16D 1/033 when connecting two faces perpendicular to the axis of rotation.

with clamping hub; with hub and longitudinal key
Definition statement
This subclass/group covers:

Used for connecting two abutting shafts or the like by means of a clamping hub or hub with a longitudinal key. Examples of clamping hubs (radial clamping/loading) and keys can be found in the titles of the subgroups of F16D 1/08.

with radial clamping due to axial loading of at least one pair of conical surfaces
Definition statement
This subclass/group covers:

Used for connecting two abutting shafts or the like by means of radial clamping due to axial loading of at least one pair of conical surfaces. Examples of this kind of clamping can be found in the subgroups of F16D 1/09.

with clamping hub; with hub and longitudinal key
Definition statement
This subclass/group covers:

Used for attachment of a member on a shaft or on a shaft end by means of a clamping hub or a hub with a longitudinal key.

{with radial clamping due to deformation of a resilient body or a body of fluid (F16D 1/091 takes precedence; elastic couplings F16D 3/80 ; fluid pressure clutches F16D 25/04) }
Definition statement
This subclass/group covers:

Used for attachment of a member on a shaft or on a shaft end by means of a radial clamping hub due to deformation of a resilient body or a body of fluid, e.g. used for hubs comprising cavities which can be pressurised by fluid, so that a wall of the hub can expand towards the shaft in order to radially clamp the shaft.

{with radial clamping due to tilting of a hub part or ring about a diametral axis}
Definition statement
This subclass/group covers:

Used for attachment of a member on a shaft or on a shaft end by means of a radial clamping hub due to tilting of a hub part or ring about a diametral axis, meaning that radially clamping is achieved by means of tilting of a hub part or ring about an axis perpendicularly crossing the rotational axis.

{with radial clamping due to rotation along an eccentric surface, e.g. arcuate wedging elements ( similar clutches F16D 17/00 ; similar free-wheel clutches F16D 41/06) }
Definition statement
This subclass/group covers:

Used for attachment of a member on a shaft or on a shaft end by means of a radial clamping hub due to rotation along an eccentric surface, e.g. arcuate wedging elements on the inner surface of the hub and/or the mating outer surface of the shaft, whereby clamping is achieved when the shaft and hub are relatively rotated and the elements wedge.

{with radial clamping of a helical wrap spring on the shaft or in the hub bore ( similar clutches F16D 13/025 , F16D 13/08 , F16D 27/025 , F16D 27/105 ; similar slip couplings F16D 7/022 ; similar free-wheel clutches F16D 41/206) }
Definition statement
This subclass/group covers:

Used for attachment of a member on a shaft or on a shaft end by means of a radial clamping hub due to clamping of a helical wrap spring on the shaft or in the hub bore, e.g. by expanding the wrap spring against the hub bore due to relative rotation of the spring ends around the rotational axis.

{with radial clamping due to a radial screw}
Definition statement
This subclass/group covers:

Used for attachment of a member on a shaft or on a shaft end by means of a radial clamping hub due to clamping by a set screw, e.g. a screw screwed in the hub in a radial direction through the hub and ending in the hub bore and thereby hitting the shaft outer surface.

{due to the elasticity of the hub (including shrink fits) }
Definition statement
This subclass/group covers:

Used for attachment of a member on a shaft or on a shaft end by means of a radial clamping between the mating surfaces of the hub and the shaft due to the elasticity of the hub, e.g. a hub is heated (to enlarge its bore), is then put on the shaft and subsequently cooled in order to crimp or e.g. a hub is press fit on a shaft.

{due to tangential loading of the hub, e.g. a split hub}
Definition statement
This subclass/group covers:

Used for attachment of a member on a shaft or on a shaft end by means of a radial clamping between the mating surfaces of the hub and the shaft due to tangential loading of the hub, e.g. a split hub, meaning e.g. a hub which has a radial split in the direction of the rotational axis, whereby the parts of the hub adjacent to the split and facing each other are clamped together by e.g. a screw so that the bore of the hub clamps around the shaft.

with radial clamping due to axial loading of at least one pair of conical surfaces { ( tapered keys F16D 1/0882) }
References relevant to classification in this group
This subclass/group does not cover:
Tapered keys
and comprising a chamber including a tapered piston moved axially by fluid pressure to effect clamping
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 1/091.

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the pair of conical mating surfaces being provided on the coupled hub and shaft
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 1/092.

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using one of more elastic segmented conical rings forming at least one of the conical surfaces, the rings being expanded or contracted to effect clamping (F16D 1/091 akes precedence )
References relevant to classification in this group
This subclass/group does not cover:
Couplings comprising a chamber including a tapered piston moved axially by fluid pressure to effect clamping

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using one or more pairs of elastic or segmented rings with mutually mating conical surfaces, one of the mating rings being contracted and the other being expanded
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 1/094.

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with clamping effected by ring contraction only { ( for connecting two abutting shafts F16D 1/02) }
Definition statement
This subclass/group covers:

Used for attachment of a member on a shaft or on a shaft-end with clamping hub, with radial clamping due to axial loading of at least one pair of conical surfaces, using one of more elastic segmented conical rings forming at least one of the conical surfaces, the rings being contracted to effect clamping, with clamping effected by ring contraction only, e.g. used for the following arrangements: see figure:

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the rings 9,10 are stiff and the elastic ring 3 is contracted when the rings 9,10 are loaded (when the bots are tightened).

References relevant to classification in this group
This subclass/group does not cover:
Couplings for connecting two abutting shafts
the ring or rings being located between the shaft and the hub
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 1/096.

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with clamping effected by ring expansion only, e.g. with an expanded ring located between hub and shaft
Definition statement
This subclass/group covers:

Used for attachment of a member on a shaft or on a shaft-end with clamping hub, with radial clamping due to axial loading of at least one pair of conical surfaces, using one of more elastic segmented conical rings forming at least one of the conical surfaces, the rings being expanded to effect clamping, with clamping effected by ring expansion only, e.g. used for the following arrangements: see figure (the elastic ring 45 is expanded between the shaft part 13 and the hub 3 when screwed on the shaft end 14):

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Yielding couplings, i.e. with means permitting movement between the connected parts during the drive ( couplings disconnectable simply by axial movement F16D 1/10 ; slip couplings F16D 7/00)
References relevant to classification in this group
This subclass/group does not cover:
Couplings disconnectable simply by axial movement
Slip couplings
the rolling members being guided in grooves in both coupling parts
Definition statement
This subclass/group covers:

Universal joints in which flexibility is produced by means of rolling connecting parts, one coupling part entering a sleeve of the other coupling part and connected thereto by rolling members whereby the rolling members are being guided in grooves in both coupling parts.

Details of ball cages
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2003/22303.

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having counter tracks, i.e. ball track surfaces which diverge in opposite directions
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2003/22306.

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Details of grooves
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2003/22309.

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Details of the inner part of the core or means for attachment of the core on the shaft
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2003/22313.

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Means for fastening or attaching the bellows or gaiters
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2003/22316.

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Elements arranged in the hollow space between the end of the inner shaft and the outer joint member
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2003/2232.

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Attachments to the shaft of the inner joint member whereby the attachments are distanced from the core
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2003/22323.

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Attachments to the outer joint member, i.e. attachments to the exterior of the outer joint member or to the shaft of the outer joint member
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2003/22326.

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where the track is made up of two curves with a point of inflexion in between, i.e. S-track joints
Definition statement
This subclass/group covers:

Universal joints where the rolling members are being guided in grooves on both coupling parts. The projection of the groove lines forming a S curve with an inflection point, see inner contour of part (12) and outer contour of part (16) in the figure.

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where the grooves are composed of radii and adjoining straight lines, i.e. undercut free [UF] type joints
Definition statement
This subclass/group covers:

Universal joints where the rolling members are being guided in grooves on both coupling parts. In the projection these grooves are composed of radii and straight lines, see groove line (11b) and (12b) in the figure.

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the groove centre-lines in each coupling part lying on a sphere
Definition statement
This subclass/group covers:

Universal joints where the rolling members are being guided in grooves in both coupling parts, and the groove centre-lines of each coupling part are lying on a sphere with the same centre.

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where the groove centres are offset from the joint centre
Definition statement
This subclass/group covers:

Universal joints where the rolling members are being guided in grooves in both coupling parts, the groove centre-lines are lying on spheres and the centres of these spheres (D1, G1) are offset from the joint centre (E1).

Each complete groove centre-line lying on (a part of) a single sphere.

References relevant to classification in this group
This subclass/group does not cover:
In case the groove centre-lines are composed of combinations of parts of several spheres

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the groove centre-lines in each coupling part lying on a cylinder co-axial with the respective coupling part
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 3/226.

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{the joints being non-telescopic}
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 3/2265.

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Prismatic coupling parts having each groove centre-line lying on planes parallel to the axis of the respective coupling part (F16D 3/224 , F16D 3/226 take precedence )
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 3/229.

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with a coupling element in the form of a pneumatic tube ( similar clutches F16D 25/04)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Similar clutches
Slip couplings, e.g. slipping on overload, for absorbing shock ( combined with yielding shaft couplings F16D 3/14 ; fluid slip couplings F16D 31/00 to F16D 35/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Combined with yielding shaft couplings
Fluid slip couplings
Gearings with arrangements or devices for absorbing overload or preventing damage by overload
of the friction type (couplings in which overload initiates a decrease of coupling pressure or a disconnection, see the relevant groups for clutches { e.g. for friction overload clutches F16D 43/21} )
Informative references
Attention is drawn to the following places, which may be of interest for search:
Couplings in which overload initiates a decrease of coupling pressure or a disconnection, see the relevant groups for clutches e.g. for friction overload clutches
of the ratchet type ( similar gearings based on repeated accumulation and delivery of inertia-energy F16H 33/08 ; { overload clutches of the ratchet type F16D 43/202} )
Informative references
Attention is drawn to the following places, which may be of interest for search:
Overload clutches of the ratchet type
Clutches in which the members have interengaging parts ( arrangements for synchronisation F16D 23/02)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Arrangements for synchronisation
Friction clutches ( arrangements for synchronisation F16D 23/02)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Arrangements for synchronisation
with a helical band or equivalent member, which may be built up from linked parts, with more than one turn embracing a drum or the like, with or without an additional clutch actuating the end of the band (F16D 13/02 takes precedence; { similar slip couplings F16D 7/022 ; similar clutches electromagnetically actuated F16D 27/025 , F16D 27/105} ; similar free-wheel clutches F16D 41/20 ; similar brakes F16D 49/02)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Similar clutches electromagnetically actuated
F16D 7/022, F16D27/10C
Similar slip clutches
Similar freewheel clutches
Similar brakes
with clutching members co-operating with the periphery of a drum, a wheel-rim, or the like (F16D 13/02 to F16D 13/08 take precedence; similar brakes F16D 49/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Similar brakes
with an expansible band or coil co-operating with the inner surface of a drum or the like (F16D 13/02 takes precedence; similar brakes F16D 51/02)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Similar brakes
with outwardly-movable clutching members co-operating with the inner surface of a drum or the like (F16D 13/02 , F16D 13/06 , F16D 13/12 take precedence; similar brakes F16D 51/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Similar brakes
with clutching members co-operating with both the periphery and the inner surface of a drum or wheel-rim ( similar brakes F16D 53/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Similar brakes
with axially-movable clutching members ( similar brakes F16D 55/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Similar brakes
Details { ( tools for assembling or disassembling clutches B25B 27/0064) }
References relevant to classification in this group
This subclass/group does not cover:
Tools for assembling or disassembling clutches
Clutching elements ( friction lining or attachment thereof F16D 69/00)
References relevant to classification in this group
This subclass/group does not cover:
Friction lining or attachment thereof
Clutch-bands; Clutch shoes; Clutch-drums ( brake-bands, brake-shoes, brake-drums F16D 65/00)
References relevant to classification in this group
This subclass/group does not cover:
Brake-bands, brake-shoes, brake-drums
Clutch-plates; Clutch-lamellae ( brake-plates, brake-lamellae F16D 65/12)
References relevant to classification in this group
This subclass/group does not cover:
Brake-plates, brake-lamellae
Attachments of plates or lamellae to their supports { ( one or more discs connected to the linings transmitting torque to one or more discs connected to the hub by helical springs in windows in the discs, i.e. rotary vibration dampers F16F 15/12) }
References relevant to classification in this group
This subclass/group does not cover:
One or more discs connected to the linings transmitting torque to one or more discs connected to the hub by helical springs in windows in the discs, i.e. rotary vibration dampers
Pressure members, e.g. pressure plates, for clutch-plates or lamellae; Guiding arrangements for pressure members { ( clutch flywheels comprising two or more masses with a rotational damper F16F 15/12) }
References relevant to classification in this group
This subclass/group does not cover:
Clutch flywheels comprising two or more masses with a rotational damper
F16F15/12K
Clutches with wedging balls or rollers or with other wedgeable separate clutching members ( freewheels, freewheel clutches F16D 41/00)
References relevant to classification in this group
This subclass/group does not cover:
Freewheels, freewheel clutches
Systems comprising a plurality of actuated clutches ( for synchronisation F16D 23/04)
References relevant to classification in this group
This subclass/group does not cover:
For synchronisation
for interconnecting three or more shafts or other transmission members in different ways ( in endless-track vehicles B62D)
Informative references
Attention is drawn to the following places, which may be of interest for search:
In endless-track vehicles
at least two driving shafts or two driven shafts being concentric
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Mechanically actuated clutches
include also clutches other than mechanically actuated, e.g. electrically or hydraulically actuated
Arrangements for synchronisation, also for power-operated clutches ( shape or mounting of interengaging parts of clutch members to facilitate engagement F16D 11/08)
References relevant to classification in this group
This subclass/group does not cover:
Shape or mounting of interengaging parts of clutch members to facilitate engagement
with a blocking mechanism that only releases the clutching member on synchronisation ( in combination with an additional friction clutch F16D 23/06)
References relevant to classification in this group
This subclass/group does not cover:
In combination with an additional friction clutch
Mechanical clutch-actuating mechanisms arranged outside the clutch as such ( specific for combined clutches F16D 21/00 ; mechanisms specific for synchronisation F16D 23/02)
References relevant to classification in this group
This subclass/group does not cover:
Specific for combined clutches
Mechanisms specific for synchronisation
Fluid-actuated clutches
References relevant to classification in this group
This subclass/group does not cover:
Fluid actuated torque limiting clutches
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Fluid
any gas or liquid, e.g. for pneumatic or hydraulic control
Hydraulic devices that initiate movement of pistons in slave cylinders for actuating clutches, i.e. master cylinders
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2025/081.

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{the line of action of the fluid-actuated members co-inciding with the axis of rotation}
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 25/082.

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Clutch systems with a plurality of fluid-actuated clutches ( arrangements or mounting of clutches in vehicles B60K 17/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Arrangements or mounting of clutches in vehicles
Magnetically- {or electrically-} actuated clutches; Control or electric circuits therefor ( clutches with magnetisable particles F16D 37/02 ; { with electro-rheological fluids F16D 37/008} )
References relevant to classification in this group
This subclass/group does not cover:
Clutches with electro-rheological fluids
Clutches with magnetisable particles
Magnetic clutches e.g. electrostatic or Eddy current clutches
Electrically-actuated clutches ( arrangements for synchronisation F16D 23/02 ; clutches actuated directly by means of an electromagnet F16D 27/00 ; automatic clutches F16D 43/00 to F16D 45/00 ; external control F16D 48/00)
References relevant to classification in this group
This subclass/group does not cover:
Clutches actuated directly by means of an electromagnet
Clutches with magnetisable particles
Clutches with electro-rheological fluids
Magnetic clutches e.g. electrostatic or Eddy current clutches
Rotary fluid couplings or clutches of the hydro-kinetic type
References relevant to classification in this group
This subclass/group does not cover:
Retarders
Torque converters
by means arranged externally of the coupling or clutch ( mounting of such means in vehicles B60K 23/00 , e.g. B60K 23/02)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Mounting of such means in vehicles
Details ( applicable also to fluid gearing F16H 41/24)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Applicable also to fluid gearing
Fluid clutches in which the clutching is predominantly obtained by fluid adhesion (F16D 37/00 takes precedence ) { ( arrangements of viscous clutches in four-wheel drives - B60K 17/3465 and B60K 17/351) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Arrangements of viscous clutches in four-wheel drives
Freewheels or freewheel clutches ( cycle brakes controlled by back-pedalling B62L 5/00 ; { one-way linear clutches F16B 7/16} )
Informative references
Attention is drawn to the following places, which may be of interest for search:
Cycle brakes controlled by back-pedalling
One-way linear clutches
F16B7/16
Automatic clutches ( varying the relationship between two coaxial shafts F16D 3/10 ; freewheels, freewheel clutches F16D 41/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Couplings for varying the relationship between two coaxial shafts
Freewheels, freewheel clutches
controlled by angular speed (F16D 43/24 takes precedence; clutches in which the drive is transmitted through a medium consisting of small particles F16D 37/00)
References relevant to classification in this group
This subclass/group does not cover:
Clutches in which the drive is transmitted through a medium consisting of small particles
of the ratchet type ( slip couplings of the ratchet type F16D 7/04)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Slip couplings of the ratchet type
with intermediate balls or rollers
Informative references
Attention is drawn to the following places, which may be of interest for search:
Slip couplings with intermediate balls or rollers
moving axially between engagement and disengagement
Informative references
Attention is drawn to the following places, which may be of interest for search:
Corresponding slip couplings
moving radially between engagement and disengagement
Informative references
Attention is drawn to the following places, which may be of interest for search:
Corresponding slip couplings
with friction members ( { slip couplings of the friction type F16D 7/02} )
Informative references
Attention is drawn to the following places, which may be of interest for search:
Corresponding slip couplings
acting at definite angular position or disengaging after {consecutive} definite number of rotations ( actuating by means of stationary abutment F16D 11/02 , F16D 13/02 , F16D 15/00 ; control of change-speed or reversing-gearings conveying rotary motion F16H 59/00 to F16H 63/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Actuating by means of stationary abutment
Control of change-speed or reversing-gearings conveying rotary motion
of which at least one is a freewheel (F16D 47/02 , F16D 47/06 take precedence; freewheels combined with a clutch to lock the driving and driven members of the freewheel F16D 41/04 , F16D 41/26)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Freewheels combined with a clutch to lock the driving and driven members of the freewheel
characterised by fluid valves having control pistons, e.g. spools
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0209

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Details of pistons for master or slave cylinders especially adapted for fluid control ( for other details of pistons in master or slave cylinders F16D 2025/081 or F16D 25/082)
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0212.

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Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of pistons in master or slave cylinders
Valves for clutch control systems; Details thereof
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0221.

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Details of conduits, connectors or the adaptors therefor specially adapted for clutch control
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0224.

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by pedal actuation ( for pedals per se G01G 1/30)
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/023.

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Informative references
Attention is drawn to the following places, which may be of interest for search:
Pedals per se
by rotary pump actuation
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0233.

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with multiple independent pumps, e.g. one per clutch, or for supplying fluid to different systems
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0236.

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One fluid source supplying fluid at high pressure and one fluid source supplying fluid at low pressure
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0239.

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Two or more rotating pumps driven together by the same power source, e.g. connected by a shaft, or a single pump having two or more fluid outputs
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0242.

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Electrically driven rotary pumps
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0245

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Reversible rotary pumps, i.e. pumps that can be rotated in the two directions.
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0248.

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Electric motor driving a piston, e.g. for actuating the master cylinder ( for details of the actuator per se F16D 29/00)
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0251.

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Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of actuators per se
Double actuation, i.e. two actuation means can produce independently an engagement or disengagement of the clutch
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0254.

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The controlling actuation is directly performed by the pressure source, i.e. there is no intermediate valve for controlling flow or pressure
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/026.

Arrangement: Source - Actuation cylinder

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Passive valves between pressure source and actuating cylinder, e.g. check valves or throttle valves
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0263.

Arrangement: Source- Passive valves - Actuation cylinder

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Actively controlled valves between pressure source and actuation cylinder
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0266.

Arrangement: Source - Active valves - Actuation cylinder

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Single valve for switching between fluid supply to actuation cylinder or draining to the sump
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0269.

Arrangement: Source - Single valve - Actuation cylinder

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Two valves, where one valve is supplying fluid to the cylinder and the other valve is for draining fluid to the sump
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0272.

Arrangement: Source - Two valves - Actuation cylinder/Sump

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Two valves arranged in parallel, e.g. one for coarse and the other for fine control during supplying or draining fluid from the actuation cylinder
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0275.

Arrangement: Source - Two valves in parallel - Actuation cylinder

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Two valves in series arrangement for controlling supply to actuation cylinder
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0278.

Arrangement: Source - Two valves in series - Actuation cylinder

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Complex circuits with more than two valves in series or special arrangements thereof not provided for in previous groups
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0281.

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characterised by valve arrangements supplying fluid to a two chamber- cylinder
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0284.

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Hydraulic circuits combining clutch actuation with clutch lubrication or cooling
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/029.

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Hydraulic circuits combining clutch and transmission actuation
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0293.

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Hydraulic circuits controlled exclusively by hydraulic pressure, i.e. with no electrically controlled valves
Definition statement
This subclass/group covers:

Illustrative example of subject matter classified in F16D 2048/0296.

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Brakes with a braking member co-operating with the periphery of a drum, wheel-rim, or the like ( similar clutches F16D 13/10)
Definition statement
This subclass/group covers:

External drum brakes.

References relevant to classification in this group
This subclass/group does not cover:
Bicycle brakes engaging the tyre surface
B62L1/05
Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D121/00 to F16D129/00.

Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like ( similar clutches F16D 13/14)
Definition statement
This subclass/group covers:

Internal drum brakes

Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D121/00 to F16D131/00.

Brakes with braking members co-operating with both the periphery and the inner surface of a drum, wheel-rim, or the like ( similar clutches F16D 13/20)
Definition statement
This subclass/group covers:

Brakes with a drum that is engaged both radially internally and externally.

Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D121/00 to F16D131/00.

Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes ( similar clutches F16D 13/38)
Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D121/00 to F16D131/00.

by clamping an axially-located rotating disc between movable braking members, e.g. movable brake discs or brake pads
Definition statement
This subclass/group covers:

Standard disc brakes having an axially fixed disc.

with a common actuating member for the braking members
Definition statement
This subclass/group covers:

The common actuating member (e.g. caliper) is movably mounted (sliding, pivoting) in order to apply the brake force evenly on both sides of the disc.

Special rules of classification within this group

This group is used if the way of mounting of the actuating member is not relevant or not shown.

{in which the common actuating member acts on two levers carrying the braking members, e.g. tong-type brakes ( similar brakes for rail vehicles B61H 5/00) }
Definition statement
This subclass/group covers:

Tong brakes, mainly for railway vehicles.

References relevant to classification in this group
This subclass/group does not cover:
Rim brakes for bicycles
in which the common actuating member is pivoted
Definition statement
This subclass/group covers:

e.g. pivoting caliper disc brakes.

with a separate actuating member for each side
Definition statement
This subclass/group covers:

so-called fixed caliper brakes.

with a plurality of axially-movable discs, lamellae, or pads, pressed from one side towards an axially-located member
Definition statement
This subclass/group covers:

The term "plurality of" relates to stator and rotor elements, i.e. brakes with one axially movable rotor and one axially movable stator (disc or pad) fall within the scope of this class.

Brakes with only one rotating disc
Definition statement
This subclass/group covers:

Brakes with a single disc which is rotating and axially movable.

Brakes with a plurality of rotating discs all lying side by side
Definition statement
This subclass/group covers:

so-called multi-disc or lamellae brakes.

Liquid-resistance brakes; {Brakes using the internal friction of fluids or fluid-like media, e.g. powders ( for braking drums, barrels or ropes of cranes, lift hoists or winches B66D 5/026) }
Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D121/00 to F16D131/00.

Self-acting brakes, e.g. coming into operation at a predetermined speed
Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D121/00 to F16D131/00.

spring-loaded and adapted to be released by mechanical, fluid, or electromagnetic means
Definition statement
This subclass/group covers:

Spring-applied brakes, regardless of their type (drum / disc).

Special rules of classification within this group

This group is not used for classification anymore. Instead a classification for the type of brake and the appropriate codes in group F16D121/00 "for releasing a normally applied brake" is assigned.

Example:

A spring-applied, electromagnetically released fixed caliper disc brake is classified F16D 55/228 and F16D121/22.

Brakes with means for making the energy absorbed available for use (F16D 57/00 takes precedence )
References relevant to classification in this group
This subclass/group does not cover:
Electrodynamic brake systems for vehicles
Dynamo-electric brakes
Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D121/00 to F16D131/00.

Brakes not otherwise provided for; Brakes combining more than one of the types of groups F16D 49/00 - F16D 61/00
Definition statement
This subclass/group covers:

Brakes combining a plurality of brakes, each of these brakes is additionally classified in the relevant groups, e.g. a combined disc and drum brake is classified F16D 63/00 and F16D 51/00 and F16D 55/00.

Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D121/00 to F16D131/00.

Parts or details ( similar members for clutches F16D 13/58)
Definition statement
This subclass/group covers:

Brake parts, details and accessories which cannot be classified in any of the other groups or in the subgroups of F16D 65/00.

Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D121/00 to F16D131/00.

{Noise or vibration control}
Definition statement
This subclass/group covers:

Means for noise or vibration control in brakes.

References relevant to classification in this group
This subclass/group does not cover:
Resilient means interposed between pads and supporting members (so-called anti-rattle springs)
Special rules of classification within this group

If noise or vibration of a specific brake or component is controlled, an additional classification is given.

Example:

A brake disc with means for noise damping is classified F16D 65/0006 and F16D 65/12.

{Components of axially engaging brakes not otherwise provided for}
Definition statement
This subclass/group covers:

Parts of axially engaging brakes, e.g. disc brakes, which are classified F16D 55/00.

Braking members; Mounting thereof ( friction linings or attachment thereof F16D 69/00)
Definition statement
This subclass/group covers:

Members interacting with each other to produce the braking effect, including active braking members, e.g. brake pads, and passive members to be braked, e.g. brake discs and drums; Accessories for mounting, e.g. holding springs, abutments.

References relevant to classification in this group
This subclass/group does not cover:
Friction linings as such (physical aspects, e.g. shape)
Friction lining composition
Pivots or supporting members therefor
Definition statement
This subclass/group covers:

Drum brake shoe pivots or abutments, e.g. anchor blocks.

{for axially holding the segments}
Definition statement
This subclass/group covers:

e.g. springs holding drum brake shoes in contact with the brake carrier.

Pivots or supporting members therefor
Definition statement
This subclass/group covers:

e.g. details of disc brake pad abutments.

Resilient means interposed between pads and supporting members {or other brake parts}
Definition statement
This subclass/group covers:

primarily so-called anti-rattle springs.

Drums for externally- or internally-engaging brakes
Definition statement
This subclass/group covers:

Cylindrical braked members, engaged on the radially inner and/or outer side. Contains mainly brake drums for standard drum brakes, i.e. with radially inner braking surface.

References relevant to classification in this group
This subclass/group does not cover:
Rotors having both a drum and a disc part
Special rules of classification within this group

Additional classification is given in groups F16D65/13.

Discs; Drums for disc brakes
Definition statement
This subclass/group covers:

Simple disc rotors and rotors having both a drum and a disc part.

Special rules of classification within this group

Additional classification is given in groups F16D65/13.

arranged in or on the brake
Definition statement
This subclass/group covers:

Actuating mechanisms which are integrated in the brake itself.

References relevant to classification in this group
This subclass/group does not cover:
Actuation mechanisms arranged apart from the brake, e.g. connected to the brake by a rod.
adapted for drawing members together, {e.g. for disc brakes}
Definition statement
This subclass/group covers:

in particular disc brake actuators.

adapted for pressing members apart, {e.g. for drum brakes}
Definition statement
This subclass/group covers:

in particular drum brake actuators.

arranged apart from the brake
Definition statement
This subclass/group covers:

Independent actuator units, e.g. slave cylinders acting on the brake members via a rod.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Brake cylinders other than ultimate actuators
Features relating to cooling
Definition statement
This subclass/group covers:

Anything to do with cooling of brakes; e.g. modification of brakes to improve cooling, liquid cooling circuits.

References relevant to classification in this group
This subclass/group does not cover:
Internally ventilated brake discs
Brake drums with cooling fins
Vehicle modifications to facilitate cooling of brakes
Special rules of classification within this group

Additional classification is given in groups F16D78/00.

Arrangements for monitoring working conditions, e.g. wear, temperature
Definition statement
This subclass/group covers:

Devices for brake monitoring only.

References relevant to classification in this group
This subclass/group does not cover:
Monitoring brake control circuits
Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D121/00 to F16D131/00.

Combinations of couplings and brakes; Combinations of clutches and brakes ( combinations of couplings and clutches F16D 47/02 ; conjoint control of brake systems and driveline clutches in vehicles B60W 10/02 , B60W 10/18)
Definition statement
This subclass/group covers:

Arrangements combining clutches with brakes in one unit

Arrangements combining couplings with brakes in one unit

References relevant to classification in this group
This subclass/group does not cover:
Conjoint control of brake systems and driveline clutches in vehicles
Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D121/00 to F16D131/00, e.g. additional classification for indicating type of brake and actuating force are assigned.

Clutch-brake combinations
Definition statement
This subclass/group covers:

Clutches with external or internal control combined with a brake.

Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces ( clutching elements F16D 13/60 ; braking members F16D 65/02)
Definition statement
This subclass/group covers:

Friction elements characterised by their physical aspects (e.g. shape or surface structure).

References relevant to classification in this group
This subclass/group does not cover:
Braking members, e.g. assembly of friction material and support structure, friction block with backing plate
Friction lining composition
Special rules of classification within this group

Multi-aspect classification is used, i.e. not only the invention is classified, but all technical features that are considered relevant for future prior art searches should be classified by using codes in groups F16D200/00 and F16D250/00.

Compositions of linings; {Methods of manufacturing}
Definition statement
This subclass/group covers:
  • processes for making friction linings
  • special shapes or arrangements of linings
  • semi-metallic compositions e.g. metal-ceramic
References relevant to classification in this group
This subclass/group does not cover:
Informative references
Attention is drawn to the following places, which may be of interest for search:
Clutching elements
Clutch discs
F13D13/64
Braking elements
Mating compositions for stator / rotor
Layered structure
Special rules of classification within this group

Surface treatment of the friction surface F16D 69/02 and Indexing Code for "surface treatment"

{Composite materials containing carbon and carbon fibres or fibres made of carbonizable material}
Definition statement
This subclass/group covers:

C/C composites and ceramic composites : carbon/carbon composites infiltrated with Si, B or Metals.

Informative references
Attention is drawn to the following places, which may be of interest for search:
C/C composites infiltrated with silicium, in general
C/C composite materials in general
Special rules of classification within this group

For ceramic composites: F16D 69/023 and Indexing Code for "ceramic composite".

{Compositions based on metals or inorganic oxides}
Definition statement
This subclass/group covers:

Compositions containing :

  • metals or metal oxides as BINDER
  • inorganic binders
  • sintered metals
Informative references
Attention is drawn to the following places, which may be of interest for search:
Metal alloys
Type of actuator operation force
Definition statement
This subclass/group covers:

This code indicates which operation force drives the brake and is combined with a classification characterising the general structure of the brake or the actuator itself (e.g. drum / disc brake).

If different sources are present, each is classified separately, and in addition, a classification in group F16D65/14C is assigned.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Actuator components
F16D125/00
Actuators for ancillary elements like parking brake locks
F16D129/00
Electric or magnetic
References relevant to classification in this group
This subclass/group does not cover:
Electrodynamic brake systems for vehicles
Brakes comprising a medium with electrically or magnetically controlled internal friction
Dynamo-electric brakes; eddy current brakes
Multiple operation forces
Definition statement
This subclass/group covers:

This code indicates the presence of multiple independently operating actuators. Not used for plural actuators which are connected to the same power source and can only work in concert, like interconnected hydraulic cylinders.

When this code is assigned, each operation force is indexed additionally.

Components of actuators
Definition statement
This subclass/group covers:

The code is used to describe the mechanical construction of actuators; a symbol is assigned for each individual component.

Auxiliary mechanisms
Definition statement
This subclass/group covers:

Additional control mechanisms having a specific function; does not include slack adjusters (classified in group F16D38/00) or simple mechanical elements (indexed F16D125/00).

This page is owned by Office of Patent Classification.
Last Modified: 10/11/2013