Abstract: In a diaphragm spring clutch, a clutch driven plate is clampable against a rotatably driven counter - pressure plate by a pressure plate urged by a diaphragm spring. To cushion clutch re-engagements the pressure plate has an annular array of spaced lands facing the diaphragm spring and supporting a resilient fulcrum ring having spanning portions spanning the spaces between the lands, the spanning portions of the fulcrum ring being in contact with respective radial ribs on a face of the diaphragm spring. As the diaphragm spring increasingly urges the pressure plate during a clutch re-engagement, the spanning portions of the fulcrum ring are resiliently deformed by the ribs into the spaces between lands to axially cushion the re-engagement.

Abstract: A clutch cover assembly includes a diaphragm spring acting on a pressure plate through a fulcrum ring which encircles the clutch axis and is disposed in a groove in the pressure plate. The fulcrum ring is a resilient tube. During clutch re-engagements, the cross-section of the tube is resiliently deformed by the load of the diaphragm spring to provide cushioning. The resilient tube can have a slot in its outer periphery. In a first stage of cushioning the tube is deformed so as to close the slot. Thereafter, further deformation of the tube is harder and creates a second stage of harder cushioning.

Abstract: A diaphragm spring clutch cover assembly having a cover to be secured to a driven plate or flywheel and a pressure plate attached to the cover and urged by a diaphragm spring to press a driven plate against the driving plate in an assembled clutch. The diaphragm spring acts between a first fulcrum arrangement on the pressure plate and a second fulcrum arrangement on the cover. The first fulcrum arrangement comprises arcuate spaced lands in a circle on the pressure plate, a resilient wire ring engaged by the lands and spanning the spaces between the lands, and sleeves on the ring at those spaces. The sleeves are pressed axially of the clutch by the diaphragm spring so that during clutch reengagement the axial deformation of the spanning portions of the ring creates cushioning.

Abstract: A friction material and carrier plate assembly which may be used in the construction of a driven plate of a friction clutch has a flat, metal, disc-shaped, carrier plate integral with spokes co-planar with the carrier plate and radiating from the outer periphery of the plate. The spokes are adhesively bonded and/or riveted to the bases of recesses in one of the radial friction faces of a one-piece annulus of friction material, that face being proud of the spokes. The assembly is centered on an axis relative to which the annulus and spokes can flex axially.

Abstract: A friction clutch comprises a cover member, a pressure plate mounted to the cover member by drive straps and a diaphragm spring interposed between the cover member and pressure plate so as to urge the pressure plate towards and into frictional engagement with a driven plate. The diaphragm spring has the usual outer belville portion and inwardly projecting fingers. The outer parts of the fingers themselves and particularly the junctions with the belville portion are stiffened by stiffening ribs which resist finger bending and thus reduce release travel. The ribs extend into and terminate within the belville portion without reaching its outer periphery. Fulcrum rings such as 17 incorporate raised bridge portions to provide clearance for the ribs.