A MASTER CYLINDER ASSEMBLY FOR A VEHICLE HYDRAULIC BRAKING SYSTEM

摘要

A master cylinder assembly comprising two separate master cylinders is disclosed. Pressure spaces of the master cylinders are interconnected through outlet passages and a transfer passage, and a transfer valve is housed within each outlet passage. When the master cylinders are inoperative both transfer valves are retained by yieldable spacers in intermediate positions in which a limited flow can take place through both valves in both directions. This prevents hydraulic fluid from being trapped in the transfer passage which otherwise might cause a fracture to occur upon expansion with temperature of the fluid. Each transfer valve comprises a valve member which is engageable with a seating. The yieldable spacers by which the valve members may be held away from the seatings may be the thickness of a film of hydraulic fluid therebetween. In another construction the yieldable spacers may be discrete resilient projections provided either on the seatings or on the valve members to hold the valve members away from the seatings.