Patent ID: 7629549

Claim:
A rotary switch comprising: a holder base, said holder base being an electrically insulative top-open box holding two metal contact plates and a metal connection plate bilaterally on the inside, said holder base comprising a pivot shaft upwardly extending from a bottom wall thereof and a rod protruded from a top side of a peripheral wall thereof, said metal contact plates and said metal connection plate each comprising a mounting leg respectively extending out of said holder base for mounting, said metal contact plates each comprising an electric connection portion disposed inside said holder base, said metal connection plate comprising two electric connection portions respectively disposed in contact with the electric connection portions of said metal contact plates; a rotary handle axially pivotally coupled to said pivot shaft of said holder base, said rotary handle having a bottom end fixedly provided with a circular actuating member, said circular actuating member comprising a protrusion and a recess at a bottom side thereof corresponding to the electric connection portion of one of said metal contact plates; a spring member sleeved onto said rotary handle, said spring member having one end stopped against said actuating member and an opposite end fastened to the rod of said holder base; and a top cover covered on said holder base, said top cover having an axle hole for the passing of said rotary handle; wherein when the user rotates said rotary handle on said pivot shaft through an angle, said spring member is compressed to preserve energy, and the protrusion of said actuating member is pressed on the electric connection portion of one of said metal contact plates to electrically disconnect the associating metal contact plate from the electric connection portion of said metal connection plate, thereby producing an electrical signal; when the user releases the hand from said rotary handle, said spring member releases preserved energy to return said rotary handle.