Wabco Westinghouse Fahrzeugbremsen Gmbh

Wabco Fahrzeugbremsen Gmbh

Karlheinz Brinkmann

Alfred Klatt

A fluid-pressure-operated, three position working cylinder includes a cylindrical housing having a graduated bore formed therein and a movable primary piston dividing the bore into first and second pressure chambers. A movable secondary piston surrounds a portion of the primary piston and moves relative to the primary piston within the limits of a piston stop arrangement formed on opposing surfaces of the pistons. The piston stop arrangement includes an elastic stop on the primary piston which interacts with a sloped stop formed on the secondary piston so that upon initial insertion of the secondary piston onto the primary piston, the sloped stop compresses the elastic stop. The sloped stop includes a lip portion that can contact the elastic stop so as to restrain the secondary piston from further movement in one direction relative to the primary piston. A vent passage formed in the housing allows venting of the space between the two pistons. Pressurizing valves control the venting and pressurizing operations of the working cylinder. A check valve covering the vent passage prevents dirt and moisture from invading the graduated bore and piston space.

Three-position working cylinder having dual concentric pistons

A gear positioning cylinder having forward, reverse, and neutral gear selection provided by a positioning rod attached to a main piston in which an auxiliary piston is telescopically arranged for compactness.

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Hanover, Germany

Karlheinz Brinkmann