US Patent 7291796 Press switch having a force-to-detach function

A press switch includes a base, a contractible pulling rod, an upper casing, and an actuator, and when the actuator is pressed to compress a resilient spring between the upper casing and the actuator, such that the contractible pulling rod and its press terminal move downward until two movable contact points are in contact with two fixed contact points of input/output terminal on both sides of the base to electrically connect to power supply If the actuator is released, the extension of the resilient spring lifts the contractible pulling rod and its press terminal, and thus the two movable contact points are forced to be detached from the fixed contact points of the input/output terminals on both sides, so as to disconnect the power supply. The invention can assure the safety of the use of an electric appliance product such a tool machine.