Patent attributes
A central release device (10) is disclosed having a cylinder housing (12), with a cylindrical wall (14), and a guide sleeve (16), which is arranged concentrically therewith and on which an annular piston (18), which can be operatively connected to a clutch and can be hydraulically actuated by way of a pressure chamber (20) defined by the cylindrical wall and the guide sleeve, is displaceably guided. At its end the guide sleeve has an annular flange (22) with an end face (24) facing away from the annular piston and a radially outer circumferential surface (26), by way of which flange the guide sleeve is fixed to an end face (28) of the cylinder housing. According to the invention at least one axial groove (30), which starts at the end face and in which an insert (32) is firmly fitted, gripping behind the circumferential surface of the annular flange, is formed in the cylinder housing adjacent to the annular flange, an upper side (34) of the insert facing away from the annular piston lying in a plane defined by the end face of the annular flange or in front of this plane, viewed from the annular piston. As a result, a central release device of simple design is created which has a relatively short overall axial length.