Patent ID: 8448755

Claim:
A disk brake, comprising: a friction brake lining; a brake disk; a brake piston configured to press the friction brake lining against the brake disk, the brake piston being disposed within a brake piston cylinder bore and including a piston face that is acted upon hydraulically within the brake piston cylinder bore; an auxiliary piston which is displaceable parallel to the brake disk within an auxiliary piston cylinder bore, the auxiliary piston cylinder bore being connected hydraulically with the brake piston cylinder bore through a hydraulic line, the friction brake lining being displaceable transversely and parallel to the brake disk and being braced in a circumferential direction on the auxiliary piston; and a valve disposed in the hydraulic line between the auxiliary piston cylinder bore and the brake piston cylinder bore, wherein the brake piston cylinder bore is hydraulically connected to receive brake fluid from a master cylinder through at least a portion of the hydraulic line such that the disk brake is travel-boosting, and the auxiliary piston has a restoring spring which has a spring force that acts counter to a force exerted on the auxiliary piston by the friction brake lining when the disk brake is actuated, and wherein the spring force is on an order of magnitude of a force exerted on the auxiliary piston by the friction brake lining when the disk brake is actuated to prevent locking of the brake disk.