Device for monitoring the pressure of a measurement chamber charged with the pressure of a vehicle tire

• US 5,181,418 A
• Filed: 02/19/1991
• Issued: 01/26/1993
• Est. Priority Date: 02/24/1990
• Status: Expired due to Term

• Current Assignee: Wabco Westinghouse Fahrzeugbremsen GmbH
• Original Assignee: Wabco Westinghouse Fahrzeugbremsen GmbH
• Inventors: Singbartl, Gunther, Petersen, Erwin, Bartscher, Peter, Ulrich, Helmut
• Primary Examiner(s): Wood, Donald O.
• Application Number:
  US07/657,500
• Time in Patent Office: 707 Days
• Field of Search: 73/146.3, 73/146.4, 73/146.5, 73/146.8, 73/705, 73/744, 73/745, 137/227, 137/228, 137/229, 116/34 R
• US Class Current: 73/146.3
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver

Abstract

The invention device monitors the pressure of a measurement chamber subjected to the pressure prevailing in a vehicle tire. A pressure-sensitive device scans the tire pressure with a pressure measurement member in a measurement chamber. In case of a tire-pressure drop, the tire pressure is used to actuate an auxiliary actuator (3, 24, 26). The auxiliary actuator genrates the regulating distance (s) dependent on a tire pressure drop below a pressure value required for an actuation of the actuator (13). The regulating distance (s) is recognizable by a sensor. The invention device is suitable for providing a permanent signal even in case of an absence of pressure in the measurement chamber (21).

Claims

1. A device for monitoring the pressure of a measurement chamber subjected to the pressure of a vehicle tire comprising

an actuator for generating a signal indicating a pressure drop in a measurement chamber, wherein the actuator is actuated against a force of a first spring based on the pressure in the measurement chamber;

a valve device, within the measurement chamber engaging the actuator and controlled dependent on the pressure in the measurement chamber, wherein the actuator is connected to the measurement chamber in case of a pressure drop through actuation of the valve device;

a second spring engaging the valve device for control and actuation of said valve device and thereby subjected to the pressure in the measurement chamber;

the improvement comprising

the second spring engaging with the valve device such that the second spring moves the valve device to engagement.

2. The device according to claim 1, further comprising a transfer mechanism for transferring a signal corresponding to said engagement of the valve device onto a sensor scanning operation of the valve device.

3. The device according to claim 2, wherein the transfer mechanism is formed by a bendable linkage of the kind of a Bowden cable.

4. The device according to claim 2, wherein the actuator is formed together with the transfer mechanism as a single piece, and wherein a path distance generatable with the valve device, is mechanically transferable onto the actuator.

5. The device according to claim 4, wherein the mechanical transfer of the path distance from the, valve device onto the transfer mechanism is performed after the valve device makes contact with the actuator.

6. The device according to claim 1, wherein

the valve device includes a section constructed for serving as a valve body for the valve device;

the section forms together with a seal an inlet valve, wherein the actuator is connectable with the measurement chamber through the inlet valve for a pressure application;

the section forms together with a seal an outlet valve, wherein the actuator is connectable with an atmospheric outlet port through the outlet valve, for purposes of pressure venting and pressure release.

7. The device according to claim 6, wherein the force of a pressure measurement member serves for an actuation of the valve device such that the inlet valve opens and the outlet valve closes in case of a pressure in the measurement chamber having a level value below a specified pressure.

8. The device according to claim 1, wherein

a signal-generating device is furnished with an actuating member, wherein the signal-generating device can be actuated depending on the path distance, generatable by the actuator or by the valve device, against a force of the second spring;

for example an optically perceivable signal can be generated with the signal generating device for the time duration of the generated path distance.

9. The device according to claim 8, wherein the signal-generating device is integrated into a casing surrounding the pressure-sensitive device.

10. The device according to claim 9, wherein

a signal-generating part of the actuating member is formed of a signal pin penetrating a breakthrough casing opening.

11. The device according to claim 10, wherein

the signal-generating part of the actuating member is optically emphasized by a specific coloration.

12. The device according to claim 11, wherein

the optically perceivable signal is generated by a complete or partial covering of a view window coordinated to the signal-generating device.

13. A device for monitoring the pressure of a measurement chamber subjected to the pressure of a vehicle tire comprising

a cylindrical valve body forming a valve device and controllable dependent on the pressure in the pressure measurement chamber;

a piston-shaped extension having a piston face and coaxially attached to a first axial end of the valve body, wherein the piston-shaped extension is set in motion in case of a pressure drop in the pressure measurement chamber for actuation of the valve device;

a transducing extension forming a second axial end of the valve body, wherein the cylindrical valve body, the piston-shaped extension, and the transducing extension together form an auxiliary actuator;

a pressure measurement member, disposed and structured such that the pressure measurement member engages the piston-shaped extension of the auxiliary actuator for an auxiliary generation of a regulating distance and for controlling and actuating the valve device;

a pressure measurement chamber defined by a volume space adjoining a middle section of an outside surface of the valve body, adjoining the piston face of the piston-shaped extension, and disposed such as to subject the piston-shaped extension to the pressure in the measurement chamber;

a transducing member engaged by the transducing extension, whereby the pressure measurement member acts, in case of a pressure drop, mechanically onto the piston-shaped extension;

a restoring force member engaging the transducer member;

an actuator associated with the transducing member for generating a regulating distance indicating a pressure drop in the measurement chamber, wherein the actuator is actuated by a pressure of the measurement chamber against a force of the restoring force member.

14. The device according to claim 13, wherein the transducing member is furnished by an actuator pressed by a restoring force of a spring furnishing the restoring force member.

15. The device according to claim 13, wherein the transducing member is furnished by a transfer mechanism actuated by the actuator;

wherein the transfer mechanism is furnished for transferring a control setting distance onto a sensor scanning the control setting distance;

wherein the transfer mechanism is formed by an elastic linkage of the kind of a Bowden cable.

16. The device according to claim 13,

wherein the transducing member is furnished by a transfer mechanism actuated by an actuator;

wherein the actuator is formed together with the transfer mechanism as a single piece; and

wherein a regulating distance generated with the auxiliary actuator is mechanically transferred onto the actuator;

wherein the mechanical transfer of the regulating distance is performed from the auxiliary actuator onto the transfer mechanism after the auxiliary actuator makes contact with the actuator.

17. The device according to claim 13, further comprising

a valve casing;

a first seal disposed at the valve casing for engaging the valve body, wherein the auxiliary actuator includes a first section, wherein the first section is constructed such that it serves as the valve body for the valve device and wherein the valve body with its first section engages the first seal;

a second seal disposed at the valve casing, wherein the first section forms together with the second seal an outlet valve, wherein the actuator is connectable to an atmospheric outlet port via the outlet valve for purposes of pressure venting and pressure release;

wherein the transducing member is formed by an actuator connectable to the inlet valve for providing a pressure application to the piston-shaped extension;

wherein the force of the pressure measurement member serves for an actuation of the valve device such that the inlet valve opens and the outlet valve closes in case of a pressure in the measurement chamber having a level value below a specified pressure.

18. The device according to claim 13, further comprising

a signal-generating device furnished with an actuating member, wherein the signal-generating device is actuated depending on a regulating distance furnished by the actuator or furnished by the auxiliary actuator;

a second restoring force member for providing a restoring force against motion of the actuator upon a pressure drop, wherein the signal generating device generates an optically perceivable signal for a time duration corresponding to the generated regulating distance, wherein the signal-generating device is integrated into a valve casing surrounding the pressure-sensitive device;

a signal-generating part attached to the actuating member formed by a signal pin for penetrating a breakthrough valve casing opening, wherein the signal-generating part of the actuating member is optically emphasized by a specific coloration, and wherein the optically perceivable signal is generated by a complete or partial covering of a view window coordinated to the signal-generating device.

19. The device according to claim 13, further comprising

a valve casing, wherein the auxiliary actuator is formed such that the piston-shaped extension joins a smaller outer diameter annular section and a larger outer diameter annular section, formed at the end of the actuator, which actuator is disposed in a direction toward the pressure measurement member formed as a compression spring;

wherein the valve casing comprises an intermediate annular wall disposed between the larger outer diameter section of the actuator and the extension section of the auxiliary actuator, and wherein the intermediate annular wall is furnished outside, at its end in the direction of the linkage on its larger diameter, with an outer seal for contacting the actuator, and wherein the intermediate annular wall is furnished at its end toward the compression spring with an annular second seal forming an outlet valve.

20. The device according to claim 13, further comprising

a restoring-force spring;

wherein the pressure measurement member is a compression spring;

a support seat for a first end of the restoring force spring furnished by a step between the smaller outer diameter annular section and the larger outer diameter annular section of the actuator, and wherein a second end of the restoring force spring contacts an internal edge of the valve casing;

an adjusting screw mounted to the valve casing for adjusting the tension of the compression spring;

an engagement plate contacting an end of the compression spring remote relative to the actuator position and disposed to be actuated by the adjusting screw;

a first sealing ring furnished at the larger outer diameter annular section of the actuator near the end of the actuator towards the compression spring on the outside with the larger outer diameter annular section for contacting an inner wall of the valve casing;

a second sealing ring furnished to the valve casing for contacting an outside of the piston-shaped extension for sealing the pressure measurement chamber;

a filling port attached to the valve casing for connecting to a pressure supply for pressurizing a tire;

a check valve disposed at the filling port for preventing an outflow of pressurized air from the tire upon a disconnection of the pressure supply;

a pressure inlet port attached to the valve casing for connecting the valve casing to a tire;

a breakthrough opening connecting the pressure inlet port to the pressure measurement chamber.

21. A device for monitoring the pressure of a measurement chamber subjected to the pressure of a vehicle tire comprising

an actuator for generating a signal indicating a pressure drop in a measurement chamber, wherein the actuator is actuated against a restoring force of a first spring based on the pressure in the measurement chamber;

a valve device disposed within the measurement chamber and controlled dependent on the pressure in the measurement chamber, wherein the actuator is connected to the measurement chamber in case of a pressure drop through actuation of the valve device;

a second spring engaging the valve device for control and actuation of said valve device and thereby subjected to the pressure in the measurement chamber;

the improvement comprising

an auxiliary actuator including a section, serving also as a valve body of the valve device, a piston-shaped extension, and an extension piece, wherein the second spring is disposed and structured to act on the piston-shaped extension of the auxiliary actuator, wherein the auxiliary actuator serves for an auxiliary generation of a path distance and, in case of a pressure drop, acts mechanically onto the actuator against the restoring force of the first spring or in the same direction onto a transfer mechanism actuable by the actuator.

22. The device according to claim 21, wherein a transfer mechanism is furnished for transferring the path distance onto a sensor scanning the path distance.

23. The device according to claim 22, wherein the transfer mechanism is formed by a bendable linkage of the kind of a Bowden cable.

24. The device according to claim 22, wherein the actuator is formed together with the transfer mechanism as a single piece, and wherein the path distance, generatable with the auxiliary actuator, is mechanically transferable onto the actuator.

25. The device according to claim 24, wherein the mechanical transfer of the path distance from the auxiliary actuator onto the transfer mechanism is performed after the auxiliary actuator makes contact with the actuator.

26. The device according to claim 21, wherein the valve device is formed by

the section of the auxiliary actuator, serving as the valve body for the valve device, and forming together with a first seal an inlet valve, wherein the actuator is connectable with the measurement chamber with the inlet valve for a pressure application, and by

the section of the auxiliary actuator, serving as the valve body for the valve device, and forming together with a second seal an outlet valve, wherein the actuator is connectable with an atmospheric outlet port via the outlet valve, for purposes of pressure venting and pressure release.

27. The device according to claim 26, wherein the force of the second spring serves for an actuator of the valve device such that the inlet valve opens and the outlet valve closes in case of a pressure in the measurement chamber having a level value below a specified pressure.

28. The device according to claim 21, wherein

a signal-generating device includes an actuating member, a restoring spring, and a breakthrough casing opening, wherein the signal-generating device can be actuated depending on the path distance, generatable by one of the actuator and the auxiliary actuator, against a force of the restoring spring;

for example an optically perceivable signal can be generated with the signal generating device for the time duration of the generated path distance.

29. The device according to claim 28, wherein the signal-generating device is integrated into a casing surrounding the pressure-sensitive device.

30. The device according to claim 29, wherein

a signal-generating part of the actuating member is formed of a signal pin penetrating the breakthrough casing opening.

31. The device according to claim 30, wherein

the signal-generating part of the actuating member is optically emphasized by a specific coloration.

32. The device according to claim 31, wherein

the optically perceivable signal is generated by a complete or partial covering of a view window coordinated to the signal-generating device.