| 摘要 |
A protection valve device for a spring parking brake control system has a pipe bracket for connection in a normally pressurized brake pipe, the pipe bracket having connected thereto a protection valve, a charging reset valve and a charging check valve. The protection valve has a chamber at one side of a piston normally pressurized by pressure at a spring parking brake cylinder port and monitors the spring parking brake cylinder pressure to vent fluid from the brake pipe to automatically cause an emergency brake application if such pressure indicates a spring parking brake is applied. The charging reset valve prevents the venting of brake pipe fluid during charging of the brake pipe and spring parking brake system. |
