Abstract: A friction disc clutch includes a radially extending Belleville diaphragm spring having its outer peripheral portion rigidly secured to a flywheel. In one preferred form, the diaphragm spring reacts against a fulcrum on the rear side of a pressure plate to effect engagement and release of a pull type friction clutch. A mounting portion integrally joined with the radially extending Belleville diaphragm spring, includes an annular rim for affixation to the flywheel. The result is a "cantilevered" Belleville spring action, wherein the forces obtainable are greater than those normally achieved by a Belleville having its outer portion unconstrained and hence free for axial deflection.

Abstract: A self-contained hydraulic unit is provided for controlling operation of a friction clutch assembly. The hydraulic unit is connected to a source of pressure so that when pressure is applied to the unit it responds to actuate a plurality of levers to engage the clutch. Upon removal of pressure from the hydraulic unit, spring means responds to withdraw the levers and disengage the clutch. The hydraulic unit is non-rotatably supported by the friction clutch assembly and includes an axially fixed member and an axially movable member interconnected by a sliding connection. A piston and diaphragm arrangement is provided between the fixed and movable members so that when pressure is introduced into the diaphragm the piston operates to slide the movable member relative to the fixed member by means of the sliding connection thereby actuating the levers to cause engagement of the clutch.