Parking brake control system

摘要

A parking brake control device has a differential area shuttle valve which has an outlet connected to a brake actuator and a larger area of a poppet directed to an inlet connected to a control valve for applying a parking brake pressure and a smaller area of the poppet facing a second inlet connected to a service brake pressure such that in the event of simultaneous application of parking brake and service brake pressures the shuttle valve will be moved to close off the inlet to the service brake pressure while introducing park brake pressure to the brake cylinder.