Devices for the measurement of the physical state of a pneumatic tire

• US 4,240,061 A
• Filed: 02/23/1979
• Issued: 12/16/1980
• Est. Priority Date: 03/04/1978
• Status: Expired due to Term

• Current Assignee: BTR Industries Limited (Schneider Electric SE)
• Original Assignee: Dunlop Limited (Meggitt PLC)
• Inventors: Cohen, Ellis
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US06/014,614
• Time in Patent Office: 662 Days
• Field of Search: 340/58, 340/539, 200/61.22, 200/61.25, 325/28, 325/111, 325/117, 455/40, 455/95, 455/99
• US Class Current: 340/442
• CPC Class Codes: B60C 23/0422 characterised by the type of signal transmission means
• CPC Class Codes: B60C 23/20 Devices for measuring or signalling tyre temperature only
• CPC Class Codes: G01K 13/08 in rotary movement
• CPC Class Codes: G01L 17/00 Devices or apparatus for measuring tyre pressure or the pressure in other inflated bodies

Abstract

A system for conveying to the driver of a vehicle information concerning the physical state of a tire, such as its inflation pressure, comprising an electrical signaling device mounted on the wheel and arranged to transmit signals to the driver via a circuit including a conduction path through the ground or road surface on which the vehicle is supported.

Claims

1. A system for conveying to the driver of a vehicle information concerning the physical state of a pneumatic tire fitted to a wheel of the vehicle comprising a sensing device associated with the tire and mounted on the tire or wheel for rotation therewith, a signaling device incorporated in or associated with the sensing device to generate an electrical signal bearing a known relationship to the physical state to which the sensing device is responsive, a transmitting element associated with the tire to which said electrical signal is communicated, a receiving element arranged to be in communication with the transmitting element in an electrical circuit path means comprising a portion of the tire in contact with the ground or road surface on which the vehicle is supported, the ground or road surface, and an indicating device responsive to signals received by the receiving element.

2. A system for conveying to the driver of a vehicle information concerning the physical state of a pneumatic tire fitted to a wheel of the vehicle comprising a sensing device associated with the tire and mounted on the tire or wheel for rotation therewith, a signaling device incorporated in or associated with the sensing device to generate an electrical signal bearing a known relationship to the physical state to which the sensing device is responsive, said signal being in the form of electrical oscillations, a transmitting element associated with the tire to which said electrical oscillations are communicated, a receiving element arranged to be in electrical communication with the transmitting element in an electrical circuit path means comprising a portion of the tire in contact with the ground or road surface on which the vehicle is supported, the ground or road surface, and an indicating device responsive to signals received by the receiving element.

3. A system according to claim 2 wherein the signaling device comprises an electrical oscillator associated with a sensing device in the form of a pressure responsive switch arranged to connect a power supply to the oscillator whenever the tire inflation pressure falls below a predetermined value.

4. A system according to claim 3 wherein the oscillator and pressure-responsive switch are mounted, with a power supply cell, inside the tire/rim cavity and the output from the oscillator is connected at one side to the wheel and at the other side to a transmitting element in the form of a conductor contacting the inner surface of the tire.

5. A system according to claim 4 wherein a part of the conductor lies freely inside the tire/rim cavity and is arranged so that it is moved under centrifugal force as the wheel rotates to contact the inner surface of the tread region of the tire.

6. A vehicle comprising a system in accordance with claim 2 wherein at least one wheel is carried on a support which is insulated to a considerable extent from the vehicle body, said support constituting a receiving element.

7. A vehicle comprising a system in accordance with claim 2 wherein a receiving element insulated from the vehicle chassis and wheels is arranged to receive signals from an adjacent tire.