Cable-actuated electrical safety switch device

Abstract From the Canadian patent

A piston operated by a cable stretched out within hand reach along a dangerous zone actuates a tappet whose movements is transmitted to the switch. A slider compresses a spring until in a first phase a pawl prevents the return of the tappet whereafter in a second phase the force of the spring exceeds the force necessary to retract the pins of a striker which is therefore released abruptly to operate the switch. To restore the device to its standby state a lock plug carrying a, cam adapted to release the pawl from the groove in the slider is rotated by means of a key, whereby the device indicates any operation it has made, in order to make it impossible to simulate a stoppage without leaving …