Patent ID: 6460676
Filing Date: 2002-10-08
Classification: F16D

Abstract:
A self adjusting friction clutch comprising a clutch cover (21), a pressure plate (13) rotationally fast with the cover but axially displaceable towards a driven plate (15) by spring means (12) so that the driven plate is clamped between the pressure plate and an associated flywheel (11) to engage the clutch, an adjustment device (30, 40, 44) to compensate for wear in the clutch, at least part (30, 40) of the adjustment device being located in the force path between the spring means and the pressure plate, and, at least one constant lift device (49) to limit lift of the pressure plate during clutch disengagement such that the bias force of the spring means acting on the adjustment device is reduced when the clutch is substantially full disengaged to assist operation of the adjustment device, characterised in that said at least one constant lift device comprises a lever (80) pivotally connected to one of the pressure plate or an axially fixed component of the clutch and where the lever during disengagement of the clutch contacts, at a point (86) remote from a pivot (84), an abutment (23) on the other of the pressure plate or the anally fixed component to limit lift of the pressure plate, and means (46, 50, 54, 86) to control the angular position of the lever with respect to the said one of the pressure plate or the anally fixed component to maintain the lift of the pressure plate substantially constant over the life of the clutch, the adjustment device and the constant lift device thus co-operating to maintain the clamp load of the spring means substantially constant as the clutch wears.