Pneumatic pressure monitoring system

• US 3,974,477 A
• Filed: 05/09/1974
• Issued: 08/10/1976
• Est. Priority Date: 05/09/1974
• Status: Expired due to Term

• Current Assignee: Sam R. Hester
• Original Assignee: Sam R. Hester
• Inventors: Hester, Sam R.
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/468,280
• Time in Patent Office: 824 Days
• Field of Search: 340/58, 340/57, 200/61.22, 200/61.25, 200/61.26
• US Class Current: 340/448
• CPC Class Codes: B60C 23/043 using transformer type signal transducers, e.g. rotary transformers

Abstract

An improved tire pressure monitoring system and method for detecting, for example, high pressure or low pressure of automobile tires utilizing uniquely designed magnetic coupling means for transmitting the tire high or low pressure from the rotating tire to the relatively stationary, non-rotating portion of the vehicle for indication of the state of the pressure on the operating panel of the vehicle. The novel tire pressure monitoring system is usually located on the wheel and brake drum assembly for all types of vehicles, monitoring the pressure for the appropriate vehicle tire (FIG. 1). The system includes a means for monitoring the pressure in the pneumatic tire, usually coupled directly to the tire stem. The system also includes an electrical conductor from the pneumatic pressure monitor means to ferrous core means, the composition of whose core is a material that has a relative normal permeability that is high, which is mounted on the rotating wheel hub and for which the electrical conduction means is wound around the ferrous core means forming a coil for the ferrous core means. The system also includes permanent magnet means mounted on the non-rotation axle of the wheel which magnetically couples to said ferrous core means to transmit any changes of said pressure monitoring means from the rotating tire to the relatively stationary (non-rotating) portion of the vehicle and transmits this information to alarm circuit means. The switch assembly means includes pick off coil means wrapped around the permanent magnet means to transmit signals from the pressure monitor means to the alarm circuit means by detecting changes in permeability of the ferrous core means, based on the principle of Lenz'"'"'s Law.

Claims

1. A tire pressure monitoring system for a pneumatic tire, said tire being mounted on the rotating part of a wheel assembly of a vehicle or testing assembly wherein the rotating tire is to have its pneumatic pressure continuously monitored by pressure monitoring means mounted on said tire, wherein pressure changes from normal to abnormal and abnormal to normal produce detectable changes in condition of said pressure monitoring means and wherein it is desired to transmit said changes from said pressure monitoring means to the relatively stationary part of said vehicle or said testing assembly, comprising the following interconnected electrical and mechanical components:

electrical conduction means for transmitting said change in condition of said pressure monitoring means;

said electrical conduction means being mounted on said rotating part of the wheel assembly and connected to said pressure monitoring means;

magnetic coupling means using only the law of electromagnetics known as Lenz'"'"'s Law for magnetically transmitting one of said changes in condition of said pressure monitoring means for said rotating part of the wheel assembly to the stationary part of said vehicle or testing assembly;

said magnetic coupling means being composed of two parts magnetically coupled to each other at each revolution of said rotating portion of said wheel assembly with the first of said parts mounted on said rotating portion of said wheel assembly and electrically connected to said electrical conduction means and with the second of said parts mounted to said stationary part of said vehicle or said testing assembly;

emf conduction means for transmitting said change in condition of said pressure monitoring means from said magnetic coupling means;

said emf conduction means being mounted on said stationary part of said vehicle or said testing assembly and electrically connected to said second part of said magnetic coupling means; and

circuit sensing and indication means for sensing said change in condition of said pressure monitoring means from the normal to the abnormal condition transmitted by said second part of said magnetic coupling means and indicating said change to the operator of said vehicle or said testing assembly;

said circuit sensing and indication means being mounted on said stationary part of said vehicle or said testing assembly and electrically connected to said emf conduction means.

2. The system of claim 1 wherein:

said first of said parts of said magnetic coupling means is comprised of -

first electrically conductive wire means for suppressing or permitting magnetic paths; and

ferrous core means for completing magnetic paths, said first wire means forming a coil around said ferrous core;

said ferrous core means is mounted to face said second part of said magnetic coupling means in such a manner that the magnetic circuit is completed between said parts of said magnetic means when they face each other during each cycle of said rotating part of said wheel assembly; and

said electrically conductive wire means is electrically connected to said electrical conduction means.

3. The system of claim 2 wherein said ferrous core means is a soft iron half toroid.

4. The system of claim 1 wherein:

said second of said parts of said magnetic coupling means is comprised of -

electrically conductive wire means for transmitting induced electromotive force to said circuit sensing, and indication means, and

permanent magnet means for deteting magnetic circuit completion by said ferrous core means, said second wire means forming a coil around said permanent magnet means;

said permanent magnet means is mounted to face said first part of said magnetic coupling means so that a magnetic circuit is completed between said parts of said magnetic coupling means when they face each other during each cycle of said rotating part of said wheel assembly; and

said second wire means is electrically connected to said emf conduction means.

5. The system of claim 4 wherein said permanent magnet means is a permanent magnet in the shape of a half toroid.

6. The system of claim 1 wherein said second of said parts of said magnetic coupling means is comprised of:

electrical conduction means connected to said emf means for transmitting induced electromotive force to said circuit sensing and indication means and electromagnetic means for detecting magnetic circuit completion by said first of said parts;

said electromagnetic means mounted to face said first part of said magnetic coupling means so that a magnetic circuit is completed between said parts of said magnetic coupling means when they face each other during each cycle of said rotating part of said wheel assembly.

7. The system of claim 1 wherein said emf conduction means is a pair of electrically conductive wires.

8. The system of claim 1 wherein said circuit sensing and indication means includes circuit sensing means for detection of the presence of electromotic force signaling the change in condition of the pressure monitoring means from the normal to the abnormal condition, and alarm indication means for alerting the operator, and further includes reset means for resetting said alarm indication means;

said alarm indication means being electrically connected between said reset means and said circuit sensing means;

said circuit sensing means being electrically connected to said emf conduction means.

9. The system of claim 8 wherein said circuit sensing means is comprised of relay means and trigger coil means which actuates said relay means when sufficient energy is supplied to said circuit sensing means by said emf conduction means.

10. The system of claim 9 wherein said relay means is a reed switch.

11. The system of claim 8 wherein said alarm indication means is comprised of voltage source means for powering said alarm indication means, latching relay means to sustain the alarm indication until reset by said reset means, alarm light means for giving a visual indication, and power conduction means for transmitting power between said voltage source means and said alarm light means;

said power source means being electrically connected between said circuit sensing means and said reset means;

said latching relay means being connected between said circuit sensing means and said light means and said power conduction means; and

said light means being physically mounted in the location in said vehicle or said testing assembly where the operator is located.

12. The system of claim 11 wherein said reset means comprises manual switch means for breaking the connection between said power source means and said power conduction means.

13. The system of claim 1 wherein said abnormal pressure is low pressure.

14. The system of claim 1 wherein said pressure monitoring device is a pressure switch.

15. A system for signaling conditions between moveable and relatively stationary members, wherein changes in state of conditions to be measured produce detectable changes in condition in monitoring means mounted on either said moveable or said relatively stationary member and mounted on the member where said conditions are to be measured, comprising the following interconnected electrical and mechanical components:

electrical conduction means for transmitting said change in condition of said monitoring means;

said electrical conduction means being mounted on either said moveable or said relatively stationary member and mounted on the member where said conditions are to be measured and connected to said monitoring means;

magnetic coupling means using only the law of electromagnetics known as Lenz'"'"'s Law for magnetically transmitting one of said changes in condition of said monitoring means from said moveable member to said stationary member if said conditions are to be measured on said moveable member, or from said stationary member to said moveable member if said conditions are to be measured on said stationary member;

said magnetic coupling means being composed of two parts magnetically coupled to each other at least once during the movement of said members with the first of said parts mounted on the member where said conditions are to be measured and electrically connected to said electrical conduction means and with the second of said parts mounted on the member that the first of said parts is not mounted on;

emf conduction means for transmitting said change of condition of said monitoring means;

said emf conduction means being mounted on the same member as said second part of said magnetic coupling means and electrically connected to said second part of said magnetic coupling means; and

circuit sensing means for sensing said change in condition of said monitoring means transmitted by said second part of said magnetic coupling means and producing a control signal for use by other devices;

said circuit sensing means being mounted on the same member as said emf conduction means and electrically connected to said emf conduction means.

16. The system of claim 15 wherein there is further included indication and reset means for visually or audibly indicating said change in condition transmitted by said second part of said magnetic coupling means and resetting said indication;

said indication and reset means being mounted on the same member as said circuit sensing means and electrically connected to said circuit sensing means.