TIRE PRESSURE MONITORING DEVICES

摘要

A low tire pressure monitoring device (20) that is provided within a tire valve wire stem (210) and methods of using the same. The monitoring device comprises a counter-pressure chamber (21), a flexible membrane (36), a conta ct member, counter-pressure chamber pin (230), a PC board (29), and a means for emitting a signal. The monitoring device is calibrated by trapping the tire' s initial air pressure in the counter-pressure chamber. The monitoring device (20) monitors the pressure differential between the counter-pressure chamber (21) and the tire. When the pressure differential between the pressure in th e counter-pressure chamber and the pressure within the tire exceeds a predetermined maximum pressure differential, the flexible membrane (36) is deflected so that an electrical circuit is completed and a warning signal is emitted.