초록 ▼

A hydraulic master cylinder having a cylinder body (1) with a piston (3) slidable therein. The piston carries a sealing assembly (20) to permit pressurization of a pressure chamber (6) and fluid recuperation upon retraction of the piston. The sealing assembly includes a first seal (23) of relatively

A hydraulic master cylinder having a cylinder body (1) with a piston (3) slidable therein. The piston carries a sealing assembly (20) to permit pressurization of a pressure chamber (6) and fluid recuperation upon retraction of the piston. The sealing assembly includes a first seal (23) of relatively hard material slidable against the internal cylinder wall and a relatively resilient second seal (25) arranged to act between the sealing surfaces of the piston and the first seal to provide a fluid tight pressure seal during pressurization of the chamber.

대표청구항 ▼

[ I claim:] [1.] An hydraulic master cylinder comprising a relatively movable cylinder body and piston, and sealing means between respective cooperating surfaces thereof operable to permit pressurisation of hydraulic fluid in a pressure chamber during relative movement of the body and piston in one

[ I claim:] [1.] An hydraulic master cylinder comprising a relatively movable cylinder body and piston, and sealing means between respective cooperating surfaces thereof operable to permit pressurisation of hydraulic fluid in a pressure chamber during relative movement of the body and piston in one direction for actuation of the system, and recuperation of fluid into the chamber via a recuperation port during reverse relative movement of the body and piston, the sealing means being in the form of a pressure seal assembly having a first seal part of relatively hard material slidable against one of the cooperating surfaces, and a relatively resilient second seal part arranged to act between another of the cooperating surfaces and the first seal part in order to provide a fluid-tight pressure seal during pressurisation of fluid in the chamber, the other surface being shaped so as to cause resilient deformation of the second seal part during relative movement of the cylinder body and piston in said one direction, whereby the second seal part seals against said other surface and causes radial deformation of the first seal part against said one cooperating surface to enhance sealing thereof.