Itt Industries, Inc.

International Standard Electric Corporation

Karl Keiner

Volker Berisch

Jochen Burgdorf

A hydraulically actuated wheel brake with a built-in control device comprising a brake piston including two pressure surfaces each of which defines a different one of two working chambers. The pressure fluid inlet is connected directly to one of the two working chambers and via a valve to the other of the two working chambers, the valve being actuatable upon attainment of a predetermined value of inlet pressure. The brake piston has a step in its outer periphery whose surface provides one of the two pressure surfaces. The piston is guided exclusively at its outer periphery in a cylindrical bore of a housing. Since only two parts are disposed concentrically in each other, there results ease of manufacture and a minor susceptibility to failure.

Hydraulically actuated wheel brake with a built-in pressure control

A brake pressure control valve for a vehicular brake system comprises a stepped piston having a large-diameter portion guided in a bore of a threaded housing plug and a small-diameter portion guided in a bore formed in a housing for the control valve. At the end of the piston adjacent an inlet, an axial channel has a valve seat in a cooperative relation with a closure member. The piston is displaceable from its inactive position in a valve closing direction against the force of a valve spring bearing against a fixed stop. The fixed stop is fastened to the threaded plug to rovide a predetermined preload of the valve spring. With the aid of the threaded plug, the valve closure travel can be adjusted very precisely. The pressure control valve is formed by two constructional units each of which can be preassembled, thereby providing ease of assembly, mounting and replacement.

Brake pressure control valve and a method for its assembly

A pressure reducing control unit for brake system connected in the pressure connection between a master cylinder and a slave cylinder is known. The known arrangement is, however, of great overall length and is not safe against failure as well as being expensive with regard to production. According to the present invention the differential piston is constructed as a hollow cylinder having one end thereof slidably sealed in a housing bore and its other end slidable sealed on a plug fastened to the housing and projecting into the bore of the hollow cylinder. The pressure medium inlet is arranged in the plug. The differential piston on the end remote from the plug has a radial shoulder directed inwardly acting as a valve seat and separating an inlet chamber from an outlet chamber. The valve closing member is disposed at the end of the plug adjacent the shoulder.

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Schoeffengrund, Germany

Karl Keiner