Oblon, Spivak, McClelland, Maier & Neustadt
Tire pressure indicator
 The pressure gauge of a tire pressure indicator includes a casing which has a hollow adaptor to be attached to the pneumatic tire, an air inlet and a finger piece for opening an inflating valve of the tire. A diaphragm is disposed inside the casing adjacent to the air inlet and is movable, in response to an inlet pressure entering through the air inlet, between a first position in which the inlet pressure is below a predetermined low pressure limit and a second position in which the inlet pressure is above a predetermined high pressure limit. A spring-loaded push rod is movably mounted inside the casing and is moved by the diaphragm. A signal producing unit is provided inside the casing and has first and second switch devices which are controlled by the movement of the push rod. The first switch device activates the signal producing unit when the diaphragm is in the first position. The second switch device activates the signal producing unit when the diaphragm is in the second position. 
B
B60C
inventional
Tien-Tsai
Huang