Abstract: A diaphragm clutch mechanism including a cover plate, a diaphragm, an assembly for mounting the diaphragm pivotally on the cover plate, and at least one pressure plate. The assembly comprises a crown ring and a plurality of retaining lugs on the cover plate. Each retaining lug has at its free end a bent-over portion defining a locating bend. The crown ring is interposed between the diaphragm and a support crown, which bears against the locating bends of the retaining lugs.

Abstract: A friction disc, in particular for a motor vehicle clutch, comprises a carrier member in the form of a simple thin metal radial disc, with a plurality of friction pads distributed on the carrier disc coaxially with it. Each friction pad is fastened to the carrier disc by at least one fastening member, and is in the form of two pad portions arranged respectively on either side of the carrier disc. The carrier disc is formed with windows, with each friction pad being mounted in line with a respective one of these windows, in such a way that it can at least partially engage in the window at its periphery. The window defines a tongue which is fixed with respect to the carrier disc and extends into the window, and the fastening member, or each fastening member, for each friction pad is secured to the corresponding tongue.

Abstract: A clutch includes a reaction plate, a cover plate, a pressure plate and, arranged between the pressure and reaction plates, at least one friction disc. At least one intermediate disc is also provided, being arranged to come into contact with the pressure plate. The pressure plate and the adjacent intermediate disc associated with the pressure plate are secured together by a resilient gripping action, which is exerted by axial gripping members arranged between the pressure plate and the intermediate plate.

Abstract: A clutch includes a reaction plate, a cover plate, a pressure plate, and, disposed between the pressure and reaction plates, at least two friction discs and at least two intermediate discs. The intermediate driving member has at least one thrust surface facing towards the reaction plate, with the intermediate disc adjacent to the reaction plate having a reaction surface associated with the thrust surface for cooperation with the latter so as to locate the intermediate disc axially.

Abstract: A variable speed drive system comprises a driving pulley, a driven pulley and a drive belt passing around the two pulleys. Each pulley comprises a hub and two annular flanges on the hub between which the drive belt passes. One flange is movable axially relative to the hub so that the belt is able to assume different radial positions relative to the hub. An annular diaphragm spring acts on the movable flange in the axial direction. A central part of this diaphragm spring is in axial rocking bearing engagement against an annular abutment member fastened to the hub. Flyweights constrained to rotate with the diaphragm are arranged to deform it, by virtue of the centrifugal force developed as a result of such rotation, in the direction which tends to move the movable flange towards the other flange. The diaphragm has a force/axial deformation characteristic which features a neutral point at which the force changes direction.

Abstract: A speed change device comprises a hub, two annular pulley sides disposed around the hub and facing each other, one of the pulley sides being mounted for axial movement on the hub against the bias of a diaphragm spring and an additional coil spring. The diaphragm spring has a peripheral portion rockably axially bearing against the one pulley side and a central portion having a plurality of radial fingers separated by slots, rockably axially bearing against an abutment member fixed axially relative to the hub. The additional coil spring is disposed around the hub, and bears against a shoulder fixed axially relative to the movable pulley side and against the abutment member through a central portion of the diaphragm spring. An elastic spacer is axially interposed between the coil spring and the diaphragm spring. Another spacer of elastic material is axially interposed between the diaphragm spring and the abutment member.