Abstract: For a hydraulic actuation arrangement of a motor vehicle friction clutch a hydraulic cylinder is proposed of which the cylinder, displaceably receiving a piston (7), consists of a synthetic plastics material moulding (3) and a tube piece (5) of metal arranged in the moulding (3) and guiding the piston (7). The tube piece (5) is cut off from a semi-finished tube and guided with axial play, but with resilient initial stress, in the moulding (3). Seals (27, 49) arranged at the ends of the tube part (5) seal the tube part (5) off from the moulding (3).

Abstract: The invention relates to a release system in which a release bearing is prefitted in a release fork in order to ensure mutual fixing together with the gear during transport.

Abstract: A pulled-type motor vehicle clutch to be used between a combustion engine and a gear box comprises a clutch release ring, axial movement of which results in releasing or opening the clutch. A clutch release sleeve is insertable into the clutch release ring and is connectable to the clutch release ring by a wire clip. The wire clip has a circular basic wire ring and two end portions. The wire ring extends over nearly 360.degree.. A gap is defined between the ends of the circular basic wire ring. The end portions are adjoined to the ends of the circular basic wire ring. These end portions can be engaged by hand or by a tool for widening the circular basic wire ring. The end portions cross each other. The gripping faces are directed in opposite circumferential directions away from each other such that mutually approaching said gripping faces results in widening the circular basic wire ring.

Abstract: A self-centering releaser for a pressed-type motor vehicle friction clutch comprises a sliding sleeve (1) of synthetic plastics material with an integrally formed-on annular flange (3) protruding outwards radially of the sleeve axis and having a flat abutment face (31) on at least one axial side. The releaser further comprises a deep-groove ball bearing (5) radially movably enclosing the sliding sleeve (1) on the side of the abutment face (31), which bearing is fixed on the annular flange (3) by a retaining fitting (7) which radially externally grasps over the ball bearing (5). A spring (29) acting between the retaining fitting (7) and a non-rotating outer race ring (9) of the ball bearing (5) presses the outer race ring (9) through an annular disc (35) against the abutment face (31).

Abstract: The hydraulically operable clutch release for a motor vehicle friction clutch comprises a housing part (3) of substantially ring form and an annular piston (9) guided displaceably in sealed manner in the direction of the ring axis on the housing part (3). The annular piston (9) together with the housing part (3) forms an annular hydraulic pressure chamber (15) and comprises a stop face (29) facing axially away from the pressure chamber (15). A release bearing (19) guided both axially and radially movably on the annular piston (9) has a non-rotating race ring (23) supportable radially movably on the stop face (29) of the annular piston and a rotating race ring (21) constantly abutting in radially movable manner on a release device (37) of the friction clutch. Between the housing part (3) and the annular piston (9) there is compressed an axially acting compression spring (31) for the permanent supporting of the rotating race ring (21) on the release device (37).

Abstract: A drive unit comprises a motor with a motor casing, a gear box with a gear box casing, and a pulled-type clutch for torque transmission between the motor and the gear box. The gear box casing is to be fixed to the motor casing. The clutch comprises a clutch release system for transmitting a clutch release force from an actuating pedal to a diaphragm spring of the clutch. In this clutch release system there is provided a snap connection which is closed by approaching the motor casing and the gear box casing towards the relative operative position.

Abstract: A hydraulically controlled release system for a friction clutch particularly for a motor vehicle including an annular cylinder supported at a transmission housing and having an annular piston operatively engaged therein, the piston being connected with a diaphragm spring control member of the clutch. The end of the piston facing the clutch extends axially into the annular cylinder and the opposite end of the piston which faces the transmission rests against a radially outwardly bent edge of a bearing flange operatively mounted radially within the annular piston and cylinder. The bearing flange is guided with its outer side on the inner side of the annular cylinder and carries a release bearing which is operatively interposed between the diaphragm control spring of the clutch and the release bearing.

Abstract: An operating mechanism particularly for the clutch of a motor vehicle operating to automatically change the normal actuating position of the clutch conditional upon wear includes a first lever member and a second lever member with a ratchet mechanism operatively interposed therebetween. The pawl of the ratchet mechanism is urged in a direction disengaged from the ratchet wheel of the ratchet mechanism by a control member when a boundary position of wear is reached thereby to minimize play in the clutch.