Valve mounted pneumatic tire pressure sensing switch

Claim 1

A tire pressure sensing switch device for mounting on the valve stem of a pneumatic tire comprising a. a body having axially aligned, longitudinally spaced apart threaded apertures, respectively, for mounting on a tire valve stem and for receiving a valve core, b. an orifice extending through said body transversely of and between said apertures, c. a plug of insulating material received in one end portion of said orifice, d. an electrical terminal mounted in said plug and insulated thereby from said body, e. an annular shoulder at the other end of said orifice, f. a pressure chamber between said plug and said shoulder and communicating with said apertures, g. a thin metal, dimpling-type diaphragm traversing said chamber and secured against said shoulder, h. a contact element for electrically connecting said terminal and the flexing crest of said diaphragm in one position of the latter, and i. means for making constant electrical connection with said diaphragm to complete an electrical circuit through said terminal and said diaphragm crest in said one position thereof, said diaphragm crest being adapted to respond to changed pressure condition in said pressure chamber to separate said crest from said contact element and thereby break said circuit, j. said body being substantially symmetrical and balanced about the axis of said aligned apertures to minimize bending stresses applied to the supporting tire valve stem in operation.