192 clutches and power-stop control – Clutches – Axially engaging
Reexamination Certificate
2000-01-03
2001-10-16
Bonck, Rodney H. (Department: 3681)
192 clutches and power-stop control
Clutches
Axially engaging
C192S111400
Reexamination Certificate
active
06302254
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns a friction clutch, in particular for motor vehicles, and more particularly a clutch provided with a device for compensating wear due in particular to wear of the friction linings, said device, referred to hereinafter as a wear compensator device, operating as and when said linings wear.
2. Description of Related Art
A conventional friction clutch generally includes a reaction plate, possibly in two parts to form a damper flywheel, constrained to rotate with a first shaft, usually a driving shaft such as the crankshaft of the internal combustion engine, its outside periphery supporting a cover to which at least one pressure plate is attached.
The pressure plate is constrained to rotate with the cover and the reaction plate but can be moved axially by axially acting clutch engaging means operated by clutch release means; the clutch engaging means can be coil springs or two Belleville washers disposed in series and acted on by clutch release levers forming the clutch release means; the clutch engaging and clutch release means are generally part of the same component, for example a metal diaphragm bearing on the cover; the diaphragm can be disposed in series as described in document FR-A-2 753 758 or in parallel with a Belleville washer to assist the clutch release force.
A friction disc carrying friction linings at its outside periphery and constrained to rotate with a shaft, usually a driven shaft such as the input shaft of the gearbox, is disposed between the pressure plate and the reaction plate so that it is clamped between them when the clutch is in the engaged position. The clutch engaging means move the pressure plate axially when they are actuated by a clutch release thrust bearing through the intermediary of the clutch release means.
During the service life of a clutch of the above kind the friction linings and the materials on which they bear on the pressure plate and the reaction plate wear away, which varies the position of the pressure plate and the positions of the axial action clutch engaging means and the clutch release thrust bearing, which in turn varies the clamping force between the friction disc and the pressure and reaction plates because of modifications to the working conditions of the clutch release means, and this affects the force needed to release the clutch. Providing a clutch of the above kind with a wear compensator device avoids the above drawbacks because the clutch engaging means and the clutch release thrust bearing, usually bearing at all times on the clutch release means, occupy the same position when the clutch is in the engaged position.
If a clutch is provided with a wear compensator device it is beneficial, after it has exercised its function, to return it to a position corresponding to new friction linings, for example after changing the friction disc because its linings have been worn down; this also facilitates placing the clutch in a storage configuration.
SUMMARY OF THE INVENTION
The present invention consists in a clutch including a wear compensator device in which the above manoeuvre is possible and simple to carry out, naturally without demounting the assembly constituting the clutch mechanism.
In accordance with the invention, a friction clutch, in particular for motor vehicles, of the kind including a reaction plate adapted to be constrained to rotate with a driving shaft, a friction disc carrying friction linings at its outside periphery and adapted to be constrained to rotate with a driven shaft, a pressure plate, a cover fixed to the reaction plate, axially acting clutch engaging means operated by clutch release means and operative between the cover and the pressure plate through the intermediary of bearing means, the pressure plate being constrained to rotate with the cover, able to move axially relative to the cover and acted on by return spring means biasing the pressure plate axially towards the cover, said clutch also including a wear compensator device, is characterised in that the wear compensator device comprises means for resetting it to a position corresponding to new friction linings.
Said wear compensator device advantageously includes ramp means comprising circumferentially distributed inclined ramps, said ramp means being disposed axially between the bearing means and the pressure plate and adapted to co-operate with counter-ramp means, said wear compensator device also including teeth with which a tangentially disposed lead screw co-operates, one of the two ramp members and the counter-ramp means being attached to said teeth, means for rotating the lead screw being rendered operative by wear of the friction linings when the clutch is engaged.
The axially acting clutch engaging means preferably comprise a diaphragm.
The ramp means advantageously comprise a ring comprising the ramps and the bearing means.
The counter-ramp means preferably consist in studs adapted to co-operate with the ramps of the ramp means.
The lead screw is advantageously mobile along its axis and is acted on by compensator spring means.
The means for rotating the lead screw preferably comprise a ratchet wheel constrained to rotate with the lead screw.
The lead screw and the means for rotating the lead screw are advantageously carried by a support attached to the cover.
The lead screw and the means for rotating the lead screw preferably rotate on a shaft carried by the support, the means for resetting the wear compensator device comprising rotational coupling means at the end of the lead screw for rotating the lead screw.
The rotational coupling means are advantageously adapted to receive a complementary shape end of a tool.
The rotational coupling means preferably comprise at least one axial notch adapted to receive a finger at the end of the tool; alternatively the rotational coupling means comprise a slot flanked by transverse rims.
The cover advantageously has a passage for the tool aligned with the shaft.
The teeth preferably comprise a plurality of circumferentially spaced teeth elements.
Each teeth element is advantageously globally radially aligned with a ramp.
The number of teeth elements is preferably the same as the number of ramps.
The present invention also consists in a tool for resetting a wear compensator device fitted to a clutch, said tool having features adapted to co-operate with the wear compensator device of the above clutch.
REFERENCES:
patent: 4249644 (1981-02-01), Urban
patent: 4454933 (1984-06-01), Hunnicutt et al.
patent: 4497399 (1985-02-01), Kopich
patent: 5230413 (1993-07-01), Lewis et al.
patent: 5320205 (1994-06-01), Kummer et al.
patent: 5634541 (1997-06-01), Maucher
patent: 5816379 (1998-10-01), De Briel et al.
patent: 5845750 (1998-12-01), De Briel et al.
patent: 6109412 (2000-08-01), Cole et al.
patent: 2605692 (1993-07-01), None
patent: 2739159 (1997-03-01), None
patent: 2753503 (1998-03-01), None
patent: 2753758 (1998-03-01), None
patent: 2229779 (1990-10-01), None
Blard Michel
Breton Eric
Bonck Rodney H.
Liniak Berenato Longacre & White
Valeo
LandOfFree
Friction clutch with wear take-up device provided with... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Friction clutch with wear take-up device provided with..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Friction clutch with wear take-up device provided with... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2598917