| 摘要 |
A pneumatic or hydraulic pressure sensitive safety switch circuit which transmits an impulse from a sensor to a distant electrical switch, via an operating fluid, to activate the electrical switch. The electrical switch may be a disabling switch for a dangerous machine from which sensed objects are to be protected. Check valves located in the conduits communicating between the sensors and the actuators for the electric switch allow the disabling switch to be quickly actuated, but prevent re-entry of the operating fluid into the sensor means to deactuate the disabling switch until a short time interval has elapsed. The safety switch thus is quickly actuated and slowly deactuated.
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