Switches tongue-operated

A special type of limit switch in common use in machinery safety applications is the tongue-operated switch, an example of which is shown in Fig. 13.9. In... 

Fig. 13.11 Example of tongue-operated interlocking switch with guard locking, with actuator both out of and inserted in the body of the switch.

The tongue actuator is inserted in the switch as normal, when the guard to which it is attached is closed, positively operating a set of normally open and normally closed contacts that are wired into the machinery control circuit. The tongue is automatically locked in place by a mechanical latch so that the guard cannot be opened. The tongue can only be unlatched by energising a... 

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