Device for surveillance of tire pressures

• US 5,230,243 A
• Filed: 09/12/1990
• Issued: 07/27/1993
• Est. Priority Date: 09/14/1989
• Status: Expired due to Term

• Current Assignee: Wabco Westinghouse Fahrzeugbremsen GmbH
• Original Assignee: Wabco Westinghouse Fahrzeugbremsen GmbH
• Inventors: Erich, Reinecke
• Primary Examiner(s): WOODIEL, DONALD
• Application Number:
  US07/581,526
• Time in Patent Office: 1,049 Days
• Field of Search: 73/146.8, 73/146.3, 73/146.5, 73/708, 73/729, 73/744, 116/34 R, 340/442
• US Class Current: 73/146.3
• CPC Class Codes: B60C 23/20 Devices for measuring or signalling tyre temperature only

Abstract

The tire surveillance device of the invention includes a pressure measurement member, where the signal of the pressure measurement member is corrective dependent on the temperature and evaluation unit actuated by the resulting signal. The correction member (21, 34) is disposed such that it is exposed to the temperature prevailing outside of the tire (1). The disposition of the correction member avoids considering erroneous temperatures resulting for example from a heat stream generated by the braking device in the rim of the wheel.

Claims

1. A device for tire pressure surveillance comprising

a housing disposed outside of a tire;

a pressure measurement and correction member disposed in the housing, communicating to the interior of the tire and furnishing a tire pressure dependent signal correcting the signal delivered by the pressure measurement member depending on temperature, wherein the pressure measurement and correction member is exposed to a temperature prevailing outside of the tire;

an evaluation device connected to the pressure measurement and correction member and actuated by the signal of the pressure measurement member in cases where the tire pressure drops to below a tire pressure limiting value, said evaluation device including a valve slider connected to the measurement and correction member and wherein the valve slider forms with the housing a first valve for communicating the pressure within the tire to an error signal output port when the tire pressure drops to below a tire pressure limiting value and wherein the valve slider forms with the housing a second valve to communicate ambient pressure to said error signal output port when said tire is properly inflated.

2. The device according to claim 1, wherein the pressure measurement and correction member is disposed outside of the tire.

3. The device according to claim 2, wherein the pressure measurement and correction member is of an integrated construction.

4. The device according to claim 2 further comprising

a pressure line connecting an interior of a tire to the pressure measurement and correction member, wherein the tire pressure of the tire is fed in via the pressure line.

5. The device according to claim 1, wherein the pressure measurement and correction member is a pressure measurement box.

6. The device according to claim 1, wherein the distance between the pressure measurement and correction member and the tire is at least about 0.2 times the width of the tire.

7. The device according to claim 1 further comprising

a pressure line connecting an interior of a tire to the pressure measurement and correction member, wherein the tire pressure of the tire is fed in via the pressure line, wherein the pressure measurement and correction member is a pressure measurement box and

wherein the distance between the pressure measurement and correction member and the tire is at least about 0.2 times the width of the tire.

8. Device according to claim 1, wherein the evaluation device includes an electronic circuit.

9. Device according to claim 1, wherein the pressure measurement and correction member includes a pressure measurement box.

10. Device according to claim 1, wherein the evaluation device includes an electronic circuit;

and wherein the evaluation member includes a valve slider, an electronic circuit, a temperature sensor, and a pressure measurement box.

11. Device for tire pressure surveillance with a pressure measurement and correction member (4;

11;

21,

     34) furnishing a tire pressure dependent signal and correcting depending on the temperature the signal of the pressure measurement member (2, 3;

4;

11;

21,

     34), wherein the measurement and correction member (2, 3;

4;

11;

21,

     34) is disposed outside of the tire and is subjected to a temperature prevailing outside of the tire (1), and

an evaluation device (2;

32, 24, 29, 26,

     27) actuated by the signal of the pressure measurement and correction member (2, 3;

4;

11;

21,

     34) upon dropping of the tire pressure to below a tire pressure limiting value, wherein said evaluation device includes a valve slider connected to the correction member and wherein the valve slider forms with a housing a first valve (24,

     29) for communicating the pressure within the tire to an error signal output port when the tire pressure drops to below a tire pressure limiting value and wherein the valve slider forms with the housing a second valve (26,

     27) to communicate ambient pressure to said error signal output port when said tire is properly inflated.

12. Device according to claim 11, wherein the evaluation device (2, 32, 24, 29, 26, 27) includes an electronic circuit (2).

13. Device according to claim 11, wherein the pressure measurement and correction member (11;

21,

     34) is disposed outside of the tire.

14. Device according to claim 13, wherein the pressure measurement and correction member (21, 34) is constructively integrated.

15. Device according to claim 13, wherein the tire pressure of the device is fed in via a pressure line (10).

16. Device according to claim 11, wherein the pressure measurement and correction member is a pressure measurement box (21, 34).

17. Device according to claim 11, wherein the distance between the pressure measurement and correction member and the tire is at least 1/5 of the width of the tire.

18. Device according to claim 11, wherein the pressure measurement and correction member (11;

21,

     34) is disposed outside of the tire, wherein the pressure measurement and correction member 21, 34 is constructively integrated,

wherein the tire pressure of the device is fed in via a pressure line (10),

wherein the pressure measurement and correction member is a pressure measurement box (21,

     34), and

wherein the distance between the pressure measurement and correction member and the tire is at least 1/5 of the width of the tire.

19. Device according to claim 11, wherein the pressure measurement and correction member includes a pressure measurement box (21, 34).

20. Device according to claim 11, wherein the evaluation device 2, 32, 24, 29, 26, 27) includes an electronic circuit (2).

21. A monitoring method for vehicle tire pressures comprising

sensing a pressure prevailing in a vehicle tire with a pressure measurement and correction member disposed outside of the tire, communicating to the interior of the tire and furnishing a tire pressure dependent signal;

correcting the tire pressure dependent signal depending on the temperature prevailing outside of the tire with the pressure measurement and correction member exposed to a temperature prevailing outside of the tire;

evaluating the pressure dependent signal in an evaluation device connected to the pressure measurement member;

communicating the pressure within the tire to an error signal output port when the tire pressure drops to below a tire pressure limiting value;

communicating ambient pressure to said error signal output port when said tire is properly inflated.

22. The monitoring method for vehicle tire pressures according to claim 21 further comprising disposing the pressure measurement and correction member outside of the tire.

23. The monitoring method for vehicle tire pressures according to claim 21 further comprising integrating the pressure measurement and correction member into a single integrated construction.

24. The monitoring method for vehicle tire pressures according to claim 23 further comprising mechanically expanding and contracting a pressure measurement box forming the pressure measurement and correction member for deriving a mechanical motion capable of acting on a valve member.

25. The monitoring method for vehicle tire pressures according to claim 23 further comprising placing the pressure measurement and correction member at a distance of at least about 0.2 times the width of the tire away from the tire.

26. The monitoring method for vehicle tire pressures according to claim 21 further comprising installing a a pressure line connecting an interior of a tire to the pressure measurement and correction member;

and feeding the tire pressure of the tire to the pressure measurement and correction member via the pressure line.

27. The monitoring method for vehicle tire pressures according to claim 21 further comprising

disposing the pressure measurement and correction member outside of the tire;

integrating the pressure measurement and correction member into a single integrated construction;

installing a pressure line connecting an interior of a tire to the pressure measurement and correction member;

feeding the tire pressure of the tire to the pressure measurement and correction member via the pressure line;

mechanically expanding and contracting a pressure measurement box forming the pressure measurement and correction member for deriving a mechanical motion capable of acting on a valve member; and

placing the pressure measurement and correction member at a distance of at least about 0.2 times the width of the tire away from the tire.

28. The device for tire pressure surveillance according to claim 21 further comprising

actuating a final function device depending on the evaluating of the signal of the pressure measurement member.

29. A device for tire pressure surveillance comprising:

a pressure measurement member disposed within a housing, wherein the pressure measurement member is disposed outside of the tire, being exposed to a temperature prevailing outside the tire, and connected to the interior of the tire;

a valve slider within the housing connected to said pressure measurement member;

a first valve portion formed on the slider cooperating with a first element within the housing to communicate the pressure within the tire to an error signal output port in response to the actuation of the pressure measurement member when the tire pressure drops below a tire pressure limiting value;

a second valve portion formed on the valve slider cooperating with a second element in the housing to communicate ambient pressure to said error signal output in response to the pressure measurement means when said tire is properly inflated.

30. A device for tire pressure surveillance comprising

a housing disposed outside of a tire;

a pressure measurement member disposed in the housing and communicating to the interior of the tire and furnishing a tire pressure dependent signal;

an evaluation device connected to the pressure measurement member and actuated by the signal of the pressure measurement member in cases where the tire pressure drops to below a tire pressure limiting value

and furnishing a correction member for correcting the signal delivered by the pressure measurement member depending on temperature, wherein the correction member is exposed to a temperature prevailing outside of the tire;

a valve slider disposed in the housing and connected to the evaluation device;

a first valve formed by a first portion of the slider and a portion of the housing for generating a first type signal when the tire pressure drops to below a tire pressure limiting value;

an error signal output port formed at the housing and connected to the first valve for receiving the first type signal and for communicating the first type signal;

a second valve formed by a second portion of the slider and a portion of the housing and communicating to the output port for generating a second type signal when the tire pressure is properly inflated and for delivering the second type signal to the output port.