Abstract: In a duo-servo drum brake comprising a mechanical expander adjacent a thrust bearing for supporting the brake shoes, with the expander including an operating lever to which is transmitted the operating force of an actuator substantially in a direction tangential to the edge of the brake drum. The brake shoe is movable through an expander in the direction of the operating force and connected to a thrust bearing through a prestressed spring. The spring force of the prestressed spring opposes the expanding force of the expander and exceeds the operating force required for placing the brake shoes in abutment with the brake drum on the operating lever.

Abstract: A hydraulically actuated braking apparatus, for spot-type disc brakes is disclosed including a piston having an actuating end, protrudes from the brake housing and which acts on a brake pad. The piston is provided with a shoulder, and a metal ring is mounted on the piston's outside surface. An elastic folded collar is fastened behind the metal ring. The outside surface of the piston has at least one indentation of a specific shape and size in the area of the protruding end of the piston. So as to effect a tight fit of the metal ring on the piston, projections are distributed on the inside circumference of the metal ring on elastic ring elements which elements are axially bent out of the radial plane. Guide surfaces are also distributed at the inside circumference of the ring for fastening the metal ring at the piston in a predetermined position.

Abstract: An actuating device for a disc brake, in particular for automotive vehicles, has a rotatably supported actuating member and a transforming device for transforming a rotary motion into an axial motion. A part of the transforming device may be held by a holding element whereby the transforming device may be non-rotatable and axially displaceable. The holding element has a rotatably supported part fixed to the brake housing. Friction-reducing means is provided between the rotatable part and the element fixed to the housing.

Abstract: A dust cover for cylindrical elements, in particular for a pin guide arrange of a spot-type disc brake is described and includes an elastic folded sleeve having a first end section fixable at the circumference of a first cylindrical element provided in the brake housing and a second section mounted at the circumference of a second cylindrical element with a ring which is seated on the second cylindrical element. The ring has a substantially U-shaped configuration in longitudinal section and is firmly positioned on the second cylindrical element and partly surrounds the second end section of the folded sleeve. The second end section of the sleeve is turnable inside the ring.