Patent ID: 8172049

Claim:
A quiescent-current-actuated electromagnetic spring pressure brake including torque transmission sleeves disposed between a machine wall and said brake and secured to said machine wall by fastening screws, and an axially movable armature plate having bores along its periphery to receive said torque transmission sleeves in order to transmit the braking torques in a circumferential direction, said torque transmission sleeves having on the outer periphery thereof grooves with O-rings placed therein, characterized in that at least one piston guide ring is provided in the area of torque transmission sleeves on the outer periphery of the latter adjacent the O-ring disposed in a groove, said piston guide ring being placed in the groove of said O-ring or in a separate groove and acting to provide a damping action in the circumferential direction and a sliding displacement of the armature plate in the axial direction.