Master cylinder for hydraulic brake systems

摘要

A tandem master cylinder with two central valves for hydraulic brake systems is demonstrated. An O-ring (23), designed as contact pressure element, is arranged in the pushrod piston-side end of the housing (21) of the tandem master cylinder. The O-ring is arranged between a stop disc (27) and a pressure transmitting body designed as plastic bushing (24). In its compressed state, the O-ring transmits an axial force to the secondary sleeve (25) by way of the plastic bushing (24). The secondary sleeve in turn bears on a stop disc (26). Use of the O-ring (23) as contact pressure element results in a play-free seating of the secondary assembly comprising plastic bushing (24) and secondary sleeve (25). By means of the invention a compact construction, especially a shortened overall length of the tandem master cylinder is achieved by simple, skilful means. The disc spring of the prior art, which was needed for contact pressure of the secondary assembly, can be advantageously omitted. In addition the control compression spring of the central valve of the prior art is made dispensable by simple means, that is by strengthening the central valve compression spring (22). <IMAGE>