HYDRAULIC MASTER CYLINDER Russian patent published in 1999 - IPC

FIELD: transport engineering; brake systems of vehicles. SUBSTANCE: brake master cylinder has housing, piston, valve, lock and first and second stops. Pistons slides in cylinder housing executing working stroke and compresses fluid medium in pressure chamber. valve is displaced by piston. Valve seat and valve member are made movable relative to each other for opening and closing the valve and interacting. Lock is secured in cylinder housing. First stop is designed for holding piston in pulled - in position by engagement with lock. Second stop serves for holding valve member in open position when piston is set in pulled-in position. First and second stops are made in one member. This member is arranged on piston for displacing together with piston. Second stop is located at a distance from first stop in direction opposite to working stroke of piston. Member is made in form of bushing at least partially enclosing the piston. Device is displaced by valve and passes perpendicularly through hole in bushing resting on surface defining the hole, and it is used for setting valve in open position. Bushing has longitudinal slot recess with first stop arranged at one end if recess. Hole in bushing is made close to opposite end of housing. Slot recess and hole are spaced through 90 degrees on periphery of bushing. Bushing consists of two semicylindrical parts or is made in form of common partially cylindrical member with extent exceeding semicylindrical coverage. Bushing is made of flexible material and is held inside cylinder housing owing to its flexible restoration property. Bushing has radially projecting part on its front end face for thrusting against inner wall of cylinder. Rear end face part of bushing is bevelled inwards and is designed for thrusting against outer surface of piston. EFFECT: enlarged operating capabilities. 10 cl, 6 dwg