Patent ID: 6101870
Filing Date: 2000-08-15
Classification: B60C

Abstract:
An air pressure monitoring device comprising a valve stem, through which air is charged, arranged to extend through a vehicle wheel, and a transmitter secured to the wheel to transmit a signal representing the air pressure of the wheel to a receiver installed in the vehicle, wherein the valve stem includes a threaded section, wherein the monitoring device further comprises:a case attached to the wheel, the case being connected to the valve stem;an electric circuit accommodated in the case to detect the air pressure and convert the detected pressure to an electric signal;an antenna, which radiates the signal produced by the electric circuit, arranged about the valve stem, and wherein the antenna includes:a nut fastened to the threaded section;a coil wound about the valve stem; andan insulating material for covering the coil and securing the coil to the nut; anda means for conveying the signals produced by the electric circuit to the antenna.