Patent ID: 7656281

Claim:
An external air-flow-through valve stem mounted wireless tire pressure monitoring apparatus comprising: (i) a tire valve extender in its interior having a conventional valve core in one end, an internal threaded male valve connector in the other end, an air passageway between the valve core and the connector, such that tire air being flowed into said air passageway after said valve extender being installed on a tire valve stem, said valve extender in its exterior having a rectangular middle section, said rectangular middle section having on one side a hole bored through to the said air passageway, said hole having a rubber air sealing O-ring; (ii) an electronic assembly with a combination of print circuit board, control unit, pressure sensor, radio frequency signal transmitter, antenna, and battery being held together by a fixture, said pressure sensor on said electronic assembly being adapted to be mounted on said fixture and being pressed against said O-ring of said hole to form an airtight mating, such that said pressure sensor through said hole being exposed directly to air and associated pressure in said air passageway, said fixture with said electronic assembly being adapted to strap securely on said rectangular middle section of said valve extender; (iii) a housing being adapted to contain said tire pressure monitoring apparatus for secure mounting on a tire valve stem.