Patent ID: 8006816

Claim:
A combination cylinder comprising: a service brake cylinder as an active service brake with at least one pressure-medium-actuated service brake piston that actuates a brake mechanism via a service brake piston rod; and a spring store brake cylinder as a passive parking brake with a spring store brake piston which is actuated by pressure medium counter to the action of at least one store spring with the spring store brake piston transmitting the force of the at least one store spring to the service brake piston rod in the parking braking situation, wherein: a) the parking brake force generated by the spring store brake piston is optionally introduced into a rotationally fixedly mounted thrust ring which can be actuated coaxially with respect to a central axis of the combination cylinder and which exerts axial forces on a spindle drive, wherein the spindle drive includes said thrust ring, and an axial force transmission is provided between the spindle drive and the service brake piston rod, with b) the thrust ring of the spindle drive being mounted in a rotationally fixed manner and another part of the spindle drive being rotatably mounted coaxially with respect to a central axis of the combination cylinder, and the rotational movement of the thrust ring of the spindle drive is optionally blocked by a releasable rotational lock for axial force transmission between the rotationally fixed thrust ring and the rotatable part and optionally unblocked to eliminate the axial force transmission, and with c) the rotational lock comprising a pawl which is optionally engaged into an external toothing of the rotatable part of the spindle drive and which is rotatably mounted on the thrust ring, and the releasable rotational lock being part of an emergency release device for the emergency release of the parking brake, and d) the releasable rotational lock being blocked in normal operation and being released for the emergency release of the parking brake, the combination cylinder further comprising a force-transmitting gearing being positioned relative to the central axis to compensate for torques about an axis perpendicular to the central axis.