Tire pressure indicators and methods of making and using the same

Claim 1

An air pressure indication device for use on conventional automobile tires, said tires provided with a valve stem containing a Schrader valve or similar valve, comprising, housing means, said housing means provided with an elongated chamber therein and said housing means provided with an inlet port and an outlet port, said inlet and outlet ports operably coupled to said chamber, and said outlet port communicating with the air in said tire, a support member operably mounted in said chamber, said inlet port threaded to mount on a conventional valve stem, air pressure measuring means operably mounted in said chamber, said air pressure measuring means comprising an aneroid bellows pressure measuring means and indicating means operably mounted thereon, wherein said aneroid bellows pressure measuring means comprises, a bellows operably mounted within said chamber, said bellows provided with a bellows chamber therein, said bellows being evacuated and air sealed, a first end of said bellows being attached to said support members, indicating means operably mounted on the second end of said bellows, a calibration spring operably mounted between said support member and said indicating means and disposed about said bellows, window means operably mounted in said chamber wall, said window means disposed such that when the air pressure in said tire varies, a particular portion of said indicating means is visible through said window, valve means (conventional Schrader valve or similar valve) operably mounted in said outlet port, said air pressure indication means provided with through ports, said through ports adapted to allow the tire to be filled while the device is installed on a tire.