Patent ID: 6105423
Filing Date: 2000-08-22
Classification: B29D,B60C,B60G

Abstract:
A sensor for detecting rotations at the contact patch of a pneumatic tire on a vehicle, comprising (a) two spaced apart mounting points for attachment to the radially inner surface of the tire tread region (b), a contact member between the mounting points for contacting the inner surface of the tread radius of the tire between the two mounting points, and (c) signal producing means comprising a piezo-electric device which is adapted to produce a signal when movement of the contact member occurs radially of the tire relative to the two mounting points wherein damping means are provided so that a signal is generated when the movement occurs rapidly but slow movement generates no signal so that on rotation of the tire on the vehicle a signal is produced each time the tread region to which the sensor is attached becomes changed in radius at the contact patch of the tire but when the tread radius changes slowly when there is a pressure change in the tire and the movement is slow no signal is produced.