<p>A switch includes a switching mechanism, an operating mechanism with a key which normally causes the switching mechanism to be in a switched-off condition when it is pulled out and to be displaced against a biasing force to be in a switched-on condition when the key is inserted, and a locking mechanism for maintaining the switching mechanism locked in the switched-on condition and releasing it from the locked condition if a load greater than a specified magnitude is applied to the key while the switching mechanism is locked such that the switching mechanism is set back in the switched-off condition. The switching mechanism may be contained in a head case attached to a main case containing the operating mechanism. The main case also includes a forcing mechanism which tends to force the switching mechanism in the switched-off condition. Normally when the head case is attached to the main case, the forcing mechanism is released from its forcing function but when the head case is removed from the main case, the forcing mechanism functions to displace the switching mechanism into the switched-off condition. <IMAGE></p>
