Pneumatic actuator with emergency actuation by pilot valve, for e.g. motor vehicle brakes

摘要

The housing (10) contains a rear chamber (16) and a front low pressure chamber (14), separated by the moving member (12). A third chamber (50) lies between the diaphragm (18) and the disk (52). The rear chamber (16) can be selectively connected to the chamber (50) or a high pressure source (A) by the three=way valve (14), controlled by the push-rod (34). The detector (68) actuates the selector (66) to control the connection of the chamber (50) to the low pressure source (V) or the high pressure source (A). The supplementary piercing (70) will connect the chamber (50) with the chamber (16), but only if the pressure in the chamber (50) exceeds that in the rear chamber (16).