Friction clutch, particularly for motor vehicle, comprising a wear adjusting device

A friction clutch, comprising a reaction plate adapted to be mounted in rotation on a driving shaft, a friction disc carrying friction liners at its outer periphery and adapted to be mounted in rotation on a driven shaft, a pressure plate (201), a cover plate (202) fixed on the reaction plate, axially acting resilient means (203) acting between, firstly, the cover plate (202), and secondly, the pressure plate (201) through abutment means (214), the pressure plate (201) being fixed in rotation to the cover plate (202) while being able to be displaced axially with respect thereto and being subjected to the action of resilient return means (209) for returning the pressure plate (201) axially towards the cover plate (202), the said clutch further including a wear compensating device comprising circumferentially disposed ramp means (211) located axially between the abutment means (214) and the pressure plate (201) and adapted to be driven in rotation by means of a set of teeth (218), which they carry at their periphery and with which a worm (213) cooperates, means (220) for driving the worm (213) in rotation being provided and being rendered operational by wear in the friction liners when the clutch is engaged, the means (220) for driving the worm (213) in rotation consisting of a ratchet wheel fixed to the worm (213) for rotation therewith, the worm (213) and the ratchet wheel (220) being formed in one piece, characterised by the fact that the teeth (221) of the ratchet wheel (220) are formed at the outer periphery of the thread of the worm (213).