TIRE DEFECT TESTER

• US 20090078034A1
• Filed: 05/29/2008
• Published: 03/26/2009
• Est. Priority Date: 05/29/2007
• Status: Active Grant

• Current Assignee: Paul E. Hawkins, Paul E. Hawkinson Company
• Original Assignee: Paul E. Hawkinson Company
• Inventors: Range, David E., Box, Gary William
• Granted Patent: US 8,291,753 B2
• Time in Patent Office: Days
• US Class Current: 73/146
• CPC Class Codes: G01M 17/02 Tyres
• CPC Class Codes: G01M 17/022 the tyre co-operating with rotatable rolls
• CPC Class Codes: G01M 3/40 by using electric means, e.g. by observing electric discharges
• CPC Class Codes: G01N 27/205 in insulating materials
• CPC Class Codes: G01N 27/24 Investigating the presence of flaws

Abstract

A tire defect tester and a method of operation are disclosed. In one aspect, the tire defect tester includes a first electrode arranged to direct energy toward a tire, and a second electrode arranged on an opposite side of the tire from the first electrode to receive energy passing through the tire from the first electrode. The tire defect tester further includes an energy sensor electrically connected to the second electrode and a fault indicator circuit responsive to the energy sensor and configured to indicate the presence of a flaw upon energy above a threshold level being sensed at the second electrode.

Claims

1. A tire defect tester comprising:

a first electrode arranged to direct energy toward a tire;

a second electrode arranged on an opposite side of the tire from the first electrode to receive energy passing through the tire from the first electrode;

an energy sensor electrically connected to the second electrode; and

a fault indicator circuit responsive to the energy sensor and configured to indicate the presence of a flaw upon energy above a threshold level being sensed at the second electrode.

2. The tire defect tester of claim 1, wherein the first electrode includes a high voltage probe.

3. The tire defect tester of claim 2, further comprising a signal generator configured to periodically activate the first electrode.

4. The tire defect tester of claim 3, wherein the signal generator is a periodic signal generator and includes a relaxation oscillator.

5. The tire defect tester of claim 4, wherein the relaxation oscillator includes a spark gap, one or more resistors, and one or more capacitors.

6. The tire defect tester of claim 1, wherein the energy sensor is a current sensor.

7. The tire defect tester of claim 1, wherein the fault indicator circuit includes a capacitor arranged to store energy received from the energy sensor and a comparator arranged to compare the energy received on the capacitor to the threshold level.

8. The tire defect tester of claim 7, wherein the fault indicator circuit further includes a microcontroller configured to determine the presence of a flaw in the tire based on an output received from the comparator.

9. The tire defect tester of claim 1, further comprising a motor enabling signal, electrically connecting to a motor arranged to rotate the tire.

10. The tire defect tester of claim 1, further comprising a microcontroller arranged and configured to trigger high voltage pulses at the first electrode.

11. The tire defect tester of claim 10, wherein the microcontroller is further configured to store data records related to the tire.

12. The tire defect tester of claim 11, wherein the data records include flaw records having information regarding at least one of the location of the flaw on the tire, the type of flaw, the severity of the flaw, the tire having the flaw, and the time the flaw was detected.

13. The tire defect tester of claim 1, further comprising a signal generator including:

a capacitor arranged to discharge current upon electrical connection to the high voltage probe;

a rectifier electrically connected to the capacitor and selectively connecting the capacitor to the high voltage probe; and

a transformer electrically connected between the rectifier and the high voltage probe.

14. The tire defect tester of claim 1, further comprising one or more communication interfaces connecting a high voltage assembly to a control assembly, the high voltage assembly electrically connected to the energy source and the energy sensor.

15. The tire defect tester of claim 14, wherein the one or more communication interfaces are RS-232 interfaces.

16. The tire defect tester of claim 1, wherein the energy sensor includes an electrode placed at a position opposite the energy source.

17. The tire defect tester of claim 1, further comprising a flaw indicator arranged to be activated by a control assembly upon detection of a flaw in the tire.

18. The tire defect tester of claim 1, further comprising a tire type input received by a control assembly, the tire type input regulating an energy level of a signal generated by the energy source.

19. A method of testing tires for defects, the method comprising:

directing an energy signal toward a first location on a surface of a tire;

detecting an attenuated energy signal on a surface of the tire opposite the first surface; and

comparing the attenuated energy signal to a predetermined energy signal value to determine the presence of a flaw in a tire at the first location.

20. The method of claim 19, wherein the predetermined energy signal value includes a threshold energy signal value.

21. The method of claim 20, wherein the threshold energy signal value is a signal value selected by a user.

22. The method of claim 19, wherein the predetermined energy signal value includes a previously-observed energy signal value.

23. The method of claim 19, further comprising:

rotating the tire;

directing a second energy signal toward a second location on the surface of the tire;

detecting a second attenuated energy signal on the surface of the tire opposite the first surface; and

comparing the second attenuated energy signal to the predetermined energy signal value to determine the presence of a flaw in a tire at the second location.

24. The method of claim 19, further comprising rotating the tire.

25. The method of claim 24, further comprising, upon determining the presence of a flaw in the tire, halting rotation of the tire to indicate the location of the flaw.

26. The method of claim 19, further comprising periodically generating energy signals to be directed toward a surface of the tire by an energy source.

27. The method of claim 19, further comprising storing a record of the flaw in a memory.

28. The method of claim 19, further comprising performing statistical analysis of flaws detected by the tire tester.

29. The method of claim 19, further comprising, upon detection of a flaw in the tire, activating a tire flaw indicator.

30. A tire tester comprising:

means for directing an energy signal toward a first location on a surface of a tire;

means for detecting an attenuated energy signal on a surface of the tire opposite the first surface; and

means for comparing the attenuated energy signal to a predetermined energy signal value to determine the presence of a flaw in a tire at the first location.

31. The tire tester of claim 30, wherein the means for directing an energy signal toward a first location on a surface of a tire includes an energy source.

32. The tire tester of claim 31, wherein the energy source includes a high voltage probe.

33. The tire tester of claim 30, wherein the means for detecting an attenuated energy signal on a surface of the tire opposite the first surface includes an energy sensor.

34. The tire tester of claim 33, wherein the energy sensor includes a current sensor.

35. The tire tester of claim 30, wherein the means for comparing the attenuated energy signal to a predetermined energy signal value includes a peak detector.

36. A control circuit for a tire defect tester having first and second electrodes on opposite sides of a tire, the control circuit comprising:

a pulse generator arranged to trigger a voltage pulse at a circuit output, the circuit output electrically connectable to a first electrode;

an energy sensor arranged to receive energy from a circuit input, the circuit input electrically connectable to a second electrode; and

a fault indicator circuit responsive to the energy sensor and configured to indicate the presence of a flaw upon energy above a threshold level being sensed at the circuit input.

37. A method of detecting defects in tires using a tire tester having a control circuit, the method comprising:

generating an energy signal in a control circuit;

detecting an attenuated energy signal; and

comparing the attenuated energy signal to a predetermined energy signal value to determine the presence of a flaw in a tire.