Patent ID: 6729696
Filing Date: 2004-05-04
Classification: B60T,F15B,Y10T

Abstract:
A valve assembly for an air pressure system, comprising:a double check valve, including a first inlet port, a locking pressure port and a first outlet port, being operative to place one of the first inlet port and the locking pressure port in communication with the first outlet port, and preventing communication between the first inlet port and the locking port, based on relative air pressures at the inlet and locking ports; an inlet valve including a second inlet port, a second outlet port and a control port, the control port being in communication with the first outlet port, the inlet valve being operative to place the second inlet port in communication with the second outlet port when a pressure at the control port is above a threshold, an air pressure at the second outlet port controlling an operation of a park brake of a vehicle; and a first control valve including a third inlet port, a third outlet port, a first exhaust port and a control member, the third inlet port being in communication with the second outlet port, the valve operative to place the third outlet port in communication with one of the third inlet port and the first exhaust port, depending on a position of the control member.