Brake cylinder using dual piston assemblies

摘要

A brake cylinder for use in a railway vehicle braking system is provided. The brake cylinder comprises a cylindrical casing engageable with the railway vehicle braking system, a hollow piston assembly which is mounted for reciprocal movement within the cylindrical casing and having a hollow portion defined by a back wall and at least one sidewall. A small piston assembly is positioned within this hollow portion and includes a first surface facing the back wall of the hollow portion and a peripheral edge portion for sealingly engaging an inner surface of the sidewall of the hollow portion. A first space is defined by the back wall of the hollow portion, at least a portion of the inner surface of the at least one sidewall and the first surface of the small piston. Fluid communication means are provided which are in fluid communication with the first space for supplying fluid pressure within this first space during a brake application of the railway vehicle braking system resulting in movement of the hollow piston assembly away from the small piston assembly and consequently initiating a braking sequence of the railway vehicle braking system. This fluid communication means also evacuates fluid pressure from the first space during a brake release of the railway vehicle braking system resulting in movement of the hollow piston assembly toward the small piston assembly. <IMAGE>