Remote tyre pressure sensor for motor vehicle - has coupled coils mounted on car structure and wheel respectively, with latter actuated by pressure sensitive switch

摘要

The sensor contains two transmission coils (15,16) mounted on the rim and connected via a switch (14) acted by the pressure inside the tyre. The signal from the switch (14) is transmitted from one coil (16) to one receiving coil (13) fixed on the car opposite the path of the transmission coil (16). The excitation is provided by an oscillator (24) connected to an emitting coil (11), fixed on the car opposite the other transmission coil's (15) path. The coils are mounted such that the distances between the emitting coil (11) and its transmission coil (15) and between the receiving coil (13) and its transmission coil (16) are both minimal for at least one angular position of the rim. The transmission is actuated by a tyre pressure responsive switch. This switch comprises a small, deformable cusp.