20040112129, Jun 17, 2004
Torbjorn Lundqvist - Monarch Beach CA, US
Claes Grondahl - Helsinki, FI
A low tire pressure monitoring device () that is provided within a tire valve wire stem () and methods of using the same. The monitoring device comprises a counter-pressure chamber (), a flexible membrane (), a contact member, counter-pressure chamber pin (), a PC board (), 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 () monitors the pressure differential between the counter-pressure chamber () and the tire. When the pressure differential between the pressure in the counter-pressure chamber and the pressure within the tire exceeds a predetermined maximum pressure differential, the flexible membrane () is deflected so that an electrical circuit is completed and a warning signal is emitted.