| 摘要 |
<p>A parking brake control valve and system including a spring applied brake actuator which is released by air, the control valve receiving air from the service brake reservoir and being manually controlled to deliver air to the actuator to release the brakes or to exhaust air from the actuator to apply the brakes. The control valve is automatically operated in response to pressure below a predetermined minimum in the service brake system to apply the parking brakes. In the event of automatic application of the parking brake actuator, the control valve may be manually maintained in a parking brake release position for emergency operation of the vehicle.</p> |
