Oblon, Spivak, McClelland, Maier, & Neustadt, P.C.
Tunable tire pressure indicator
 A tunable tire pressure indicator includes an elongated hollow casing and a valve-actuating member mounted to an upper end of the casing. A piston is provided movably in the casing near the valve-actuating member. A plug unit is mounted in a lower end of the casing. A spring is provided in the casing between the piston and the plug unit. A pressure indicating rod is disposed in the casing. The piston pushes the rod to extend out of the casing through the plug unit against action of the spring to provide a tire pressure reading in response to pressure entering the casing. The plug unit includes a movable member formed with a passage to permit the rod to extend slidably therethrough and to permit rotation of the movable member with the rod, and a stationary member mounted securely in the lower end of the casing and formed with a through-hole larger than cross-section of the rod to permit passage of the rod therethrough. The movable member is coupled adjustably and rotatably to the stationary member to permit adjustment in distance between the movable member and the piston to adjust initial spring force of the spring. Tuning of the tire pressure indicator to obtain a precise tire pressure reading can be achieved by adjusting the initial spring force of the spring. 
G
G01L
inventional
Tien-Tsai
Huang