Patent ID: 6968734

Claim:
A pen-shaped tire pressure gauge comprising: a hollow body having one end formed with a recessed pressure measuring head, said hollow body having the other end formed with an open end, said hollow body having its interior formed with an accommodating space, said accommodating space formed with an annular stepped surface on the inner wall near said pressure measuring head, said pressure measuring head fitted therein with a rubber ring, said rubber ring provided with a press rod protruding outward from the center, with an air intake passageway formed between said rubber ring and said press rod, said air intake passage communicating with the interior of said hollow body, said pressure measuring head having its outside fitted with a metallic protecting ring, said pressure measuring head having its backside formed integral with an exhausting push rod, said exhausting push rod not communicating with the interior of said hollow body, said hollow body having said open end provided with a combining unit; a coiled spring received in said accommodating space of said hollow body, said coiled spring having its upper end fitted with a piston facing said pressure measuring head, said piston pushing against the lower edge of said annular stepped surface of said accommodating space; a scale rod received in said coiled spring, said scale rod together with said coiled spring positioned in said hollow body, said scale rod having its outer wall marked with graduations, said scale rod having its lower end fitted with a stop ring and a stop sleeve; and a fixing cap combined with said combining unit of said open end of said hollow body, said fixing cap having one end of its inner wall formed with a stop wall, said stop wall stopping and restricting said stop sleeve and other components from dropping out of said hollow body.