Patent ID: 7009505

Claim:
A tire pressure gauge comprising: a tubular housing including a surrounding wall which surrounds a central axis and which defines an accommodation space, and an inner wall which extends from said surrounding wall in radial directions and toward the central axis, which terminates at an inner peripheral edge that defines an opening, and which divides said accommodation space into a receiving chamber and a coupling chamber that is adapted to couple with a tire nozzle of a tire; a cap secured to said surrounding wall to cover and close said receiving chamber, and having a mounting hole extending therethrough along the central axis; an air ventilating member secured to said inner wall and sealing said opening, said air ventilating member including a projection which extends along the central axis to be adapted to extend into the tire nozzle so as to permit air in the tire to enter said coupling chamber, and a vent hole which permits the air in said coupling chamber to enter said receiving chamber therethrough; a flexible diaphragm disposed in said receiving chamber to divide air-tightly said receiving chamber into compressible and expandable regions, which are proximate to said cap and said air ventilating member, respectively, said expandable region being communicated with said opening through said vent hole, said flexible diaphragm having a raised portion which is configured to be movable along the central axis towards said cap in response to an air pressure introduced into said expandable region through said vent hole; a pressure indicating member having a lower portion which includes a lower surface that abuts against said raised portion so as to be moved with said raised portion along the central axis, and an upper surface opposite to said lower surface along the central axis and confronting said cap; an adjustable member mounted in said mounting hole, and movable adjustably relative to said cap along the central axis; and a biasing member disposed between said upper surface of said lower portion of said pressure indicating member and said adjustable member to bias said pressure indicating member towards said air ventilating member against movement of said raised portion.