A friction clutch comprising;
- a reaction plate (13, 16) for rotation with a driving shaft, a friction wheel (14) which is adapted for rotation with said driving shaft and which carries friction liners (30) at its outer periphery, a pressure plate (20), axially acting resilient means (24), a cover plate (17) which is fastened on the reaction plate (13, 16), rotational coupling means (23) operatively interposed between the pressure plate (20) and an assembly consisting of the cover plate (7) and the reaction plate (13, 16), for coupling the pressure plate (20) to said assembly for rotation with, and for axial mobility with respect to the latter, wherein one of the plates consisting of the pressure plate (20) and the reaction plate (13, 16), referred to as the first plate, comprises two coaxial parts (13, 16;
- 20, 120), one of which is displaceable axially with respect to the other against the action of a wear compensating mechanism (11) interposed between said parts and comprising ramp means working between two members (4, 5), each of which is associated with a respective one of the said parts of the first plate (20;
- 13, 16), one of the latter being rotatable while the other is fixed against rotation, and a trigger (3) responsive to the state of wear of the friction liners (30), for controlling the initiation of movement of said parts of the first plate (13, 16), wherein said clutch includes a rotatable rearming member (1) associated with one of the parts of the first plate (13, 16;
- 20) and subjected to the action of locking means (2) which are controlled by the trigger (3), first circumferentially acting resilient means (6) and loose coupling means (8, 80) are interposed between the rearming member (1) and the rotatable member (4) of the wear compensating mechanism (11), the rearming member (1) is subjected to the action of second circumferentially acting resilient means (7) working against the first resilient means (6) and interposed operatively between the rearming member (1) and one of the parts of the first plate (13, 16;
- 20), and said second resilient means (7) exert on the rearming member (1) a torque which is greater than that exerted by the said first resilient means (6).