Patent ID: 6655750
Filing Date: 2003-12-02
Classification: B60T,Y10T

Abstract:
A vehicle brake system, comprising:at least one brake actuator having a service chamber and an emergency chamber, the service chamber being pressurized to apply a braking force, the emergency chamber being pressurized to hold off a braking element that otherwise provides an emergency braking force; a pressure source that provides fluid pressure to the brake actuator to control the application of a braking force; a single combination valve coupling the brake actuator emergency chamber to the pressure source, the combination valve having an inlet coupled to the pressure source and an outlet coupled to the emergency chamber, the valve including a moving member that moves responsive to pressure in the system such that the combination valve is operative as an inversion valve and a relay valve, the moving member moving responsive to pressure at the inlet from a first position where pressure is exhausted from the emergency chamber to a second position where the emergency chamber is pressurized; and wherein the combination valve includes a second inlet in communication with the service chamber and wherein a failure of pressure at the second inlet during a braking application results in movement of the moving member from the second position toward the first position such that pressure is released from the emergency chamber.