| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a pneumatic brake actuator as improvement of the conventional arrangement in which a spring-loaded brake actuator is installed being sealed tightly to arouse a problem of pressure rise and producing a vacuum. <P>SOLUTION: The pneumatic brake actuator system is equipped with a spring brake actuator and a service brake actuator, the former being composed of an air-tight housing having a spring chamber and a pressure chamber and a hollow rod installed in the spring brake actuator and movable in the axial direction in order to apply a parking brake while the latter being furnished with a service pressure chamber for applying a service brake, in which a system control valve includes a valve body capable of being installed in a hollow rod, the valve body being furnished with an opening to enable fluid communication between the spring chamber and the service pressure chamber via the hollow rod, wherein the control valve includes a membrane having a breathing hole consisting of a resilient material, and the membrane is installed in the opening in the valve body and closes the opening tightly except the breathing hole when receiving no fluid pressure equal to or above the threshold. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
