Abstract: A vehicle tire pressure indicator having a housing defining an inner chamber, an electrically insulated contact tube communicating with the inner chamber, a piston movable toward and away from the contact tube guided by the inner chamber, and an elastic seal engaged with the piston and movable in its entirety with the piston along an inner surface of the inner chamber to seal the inner chamber. A tube communicates the contact tube with the vehicle tire so that a pressure in the inner chamber corresponds to the tire pressure. The contact tube is electrically connected to alarms mounted in the cabin of the vehicle. On low pressure, the piston biases into contact with the contact tube to thereby activate the alarms to warn a truck driver of low tire pressure. The vehicle tire pressure indicator is easily mounted in the center rim of a tire by a truck driver.

Abstract: An acoustic alarm arrangement associatable with a pneumatic tire for generating a signal indicating that pressure of gas in the tire decreases from a predetermined magnitude, has a housing arranged to be connected with a tire and bounding an inner chamber, a signal element associated with the housing and actuated under the action of a strike, and a striking element movable in the inner chamber between an inoperative position in which it is spaced from the signal element and an operative position in which it approaches and strikes the latter. The striking element subdivides the inner chamber into a first compartment communicating with the interior of the tire, and a second compartment.