Patent ID: 6289790
Filing Date: 2001-09-18
Classification: B60T,F15B,F16D

Abstract:
A hydraulic control device for a clutch, especially for a motor vehicle, comprising at least one control cylinder having a first skirt (54), a cylinder body (17) having an anterior base (24) and open at the rear for receiving the first skirt (54) fastened thereto, a piston (21) sliding axially in the cylinder body (17), a piston skirt (42) referred to as a second skirt, which is fixed axially with respect to the piston (21) and which slides axially in the first skirt (54), a piston seal (41) carried by the piston (21), a second seal (41) carried by the cylinder body (17) for cooperation with the first skirt (42), a piston rod (33) having an anterior head (40) for cooperating with the piston (21), wherein the cylinder body (17), the first skirt (54) and the piston (21) are of plastics material while the second skirt (42) is of metal, and wherein the piston (21) has a front face (31) defining the hydraulic chamber (20) and a rear face (31) cooperating with the piston rod (33), wherein the piston (21) is so configured as to receive the head (40) of the piston rod (33) and surrounded by the second skirt (42), and wherein the piston seal (41) is interposed operatively between the outer periphery of the piston (21) and the inner periphery of the second skirt (42), which penetrates into the hydraulic chamber (20), wherein the piston (21) has a transverse wall (30) bounded by the front face (31) and rear face (32), and in that the transverse wall (30) is extended forward by a chimney element (34) and the base (24) of the cylinder body (17) carries an axially projecting element (28) adapted to cooperate with the chimney element (34) to limit forward displacement of the piston (21).