Patent ID: 7188563

Claim:
Piston arrangement for one of a master and slave cylinder of a hydraulic actuating device for one of a clutch and brake system on a motor vehicle, comprising a piston having an outer end with a recess, an insert suitable for fixing in the recess, said insert having a ball seat and an insertion sleeve which is undercut with respect to the ball seat, said insertion sleeve having slits and thus being expandable and, when it is fully inserted in the recess, being tightly enclosed by a piston wall which delimits the recess, and a ram which transmits actuating travels and forces, said ram having a ball end which is shaped so as to be complementary to the ball seat, which ball end can be coupled to the insert in order to mount the ram in an articulated manner via a snap connection brought about by the expandable insertion sleeve; wherein the insert is provided with a peripheral chamfer at its inner end, said peripheral chamfer being assigned, within the recess of the piston, a first stop for delimiting a first insertion travel of the insert in the recess, wherein, for bringing about the snap connection, the insert bearing against the first stop protrudes outwards with its expandable insertion sleeve substantially out of the recess of the piston, an axial pressure force that is to be exerted on the ram in order to bring about the snap connection being smaller than an axial pressure force that is to be exerted on the ram in order for the insert to slide over the first stop in the recess, and a second insertion travel of the insert which starts with the sliding-over being delimited by a second stop at the inner end of the recess.