Vehicle braking system combined control valve - has diaphragm valve chamber and piston in spring chamber incorporating equalising valve

摘要

The combined control valve for a vehicle braking system has a chamber (11) at one end containing a piston (5) controlled by a spring (6) and a second chamber (20) at the other end connected to the braking mechanism. This contains a diaphragm (17) with an operating spindle (19) inside its chamber and another spindle (12) connected to the piston acting against the other side. Incorporated in the piston is an equalising valve which when the pressure falls inside the chamber (11) behind the piston, connects this chamber with the space (10) on the other side of the piston. This equalising valve has a cylindrical valve member (22) travelling in a hole (23) through the piston, with a hollow interior containing a control spring (24). The piston has a hollow spindle (12) with a release screw inside. Alternative designs include a valve incorporated in the hollow spindle.