Patent ID: 7403105

Claim:
A tire inflation pressure sensing apparatus comprising: a pressure sensor provided on a wheel of a vehicle, said pressure sensor working to sense an inflation pressure of a tire mounted on the wheel and generate a pressure signal representative of the sensed inflation pressure of the tire; a transmitter provided on a body of the vehicle, said transmitter being configured to constantly send out a predetermined radio wave; a transceiver provided on the wheel of the vehicle, said transceiver being configured to receive the predetermined radio wave sent out from said transmitter, monitor a level of the received predetermined radio wave, and send out the pressure signal generated by said pressure sensor when a transmission of the pressure signal is required and the level of the received predetermined radio wave has reached a predetermined level; a receiver provided on the body of the vehicle, said receiver being configured to receive the pressure signal sent out from said transceiver; and a determining device provided on the body of the vehicle, said determining device being configured to determine the inflation pressure of the tire based on the pressure signal received via said receiver.