Patent ID: 6374666
Filing Date: 2002-04-23
Classification: B60C

Abstract:
A tire pressure gauge apparatus for securing to a vehicle tire valve stem mounted to a tire valve stem port in a vehicle tire, the valve stem including a tubular stem body containing a valve assembly having a valve opening means, the stem body having a stem connection end fitting sealingly to the tire valve stem port, and having a stem air receiving end, the apparatus comprising:a housing for placement in fluid communication with received air from within the tire contained within the tire valve stem; means for opening said valve opening means; and a pressure equilibration structure dividing said housing into a received air chamber and a biasing air chamber and comprising a pressure indicator element, said pressure equilibration structure and said pressure indicator element being progressively movable relative to said housing and thereby substantially continuously maintaining and re-establishing pressure equilibrium between air within said received air chamber and air within said biasing air chamber, and said pressure indicator element displaying a pressure reading of received air from within the tire which varies with the position of said pressure equilibration structure relative to said housing; such that alteration of the pressure of received air within said received air chamber from the valve stem causes movement of said equilibration structure within said housing to re-establish pressure equilibrium between biasing air sealed within said biasing air chamber and received air within said received air chamber, and movement of said equilibration structure causes said indicator element to move relative to said housing to provide a received air pressure reading.