Automatic transmission fluid tester

• US 6,680,777 B1
• Filed: 11/13/2000
• Issued: 01/20/2004
• Est. Priority Date: 11/13/2000
• Status: Expired due to Fees

• Current Assignee: Snap-On Technologies Incorporated (Snap-On Incorporated)
• Original Assignee: Snap-On Technologies Incorporated (Snap-On Incorporated)
• Inventors: Becker, Thomas P., Wollert, Gary S.
• Primary Examiner(s): Pham, Hoa Q.
• Application Number:
  US09/709,462
• Time in Patent Office: 1,163 Days
• Field of Search: 356/432-440, 356/70, 73/530.5, 732/93, 250/573, 250/577, 250/563, 250/574, 340/457.4, 340/450.3, 340/438, 475/65, 475/115, 123/196.S
• US Class Current: 356/436
• CPC Class Codes: F16H 57/0405 Monitoring quality of lubricant or hydraulic fluids
• CPC Class Codes: G01N 21/59 Transmissivity G01N21/25 takes precedence

Abstract

An automatic transmission fluid tester determines the remaining service life of automatic transmission fluid. The tester includes a radiation source for emitting radiation in the direction of an automatic transmission fluid sample under test, and a radiation receiver for detecting radiation passed through the sample. Based on the output of the radiation receiver, the tester measures the opacity of the sample. The remaining service life of the automatic transmission fluid is determined as a function of the measured opacity.

Claims

1. A system for testing automatic transmission fluid (ATF), comprising:

a radiation source for emitting radiation in a direction of ATF under test,

a radiation receiver responsive to the radiation for producing an output signal representing intensity of the radiation passed through the ATF, and

an output circuit responsive to the output signal for determining condition of the ATF,

the ATF under test being contained in a disposable container.

2. The system of claim 1, wherein the output circuit is configured to measure the opacity of the ATF.

3. The system of claim 1, wherein the output circuit is configured to compare the output signal with multiple calibration levels to provide a multiple level indication of the remaining service life of the ATF.

4. The system of claim 3, wherein each of the calibration levels corresponds to the output signal of the radiation receiver produced in response to the radiation passed through the ATF having known length of life.

5. The system of claim 4, wherein each of the calibration levels is maintained at the same level for a tested ATF of any type.

6. The system of claim 5, wherein the radiation source comprises a source of infrared radiation.

7. The system of claim 4, wherein the calibration levels are set for a particular type of a tested ATF.

8. The system of claim 7, wherein the radiation source comprises a source of red light.

9. The system of claim 1 further comprising a slot arranged between the radiation source and radiation receiver for receiving the disposable container.

10. The system of claim 1 further comprising a radiation controller for controlling radiation emitted by the radiation source.

11. The system of claim 10, wherein the radiation controller controls the radiation source to make the intensity of the emitted radiation sufficient to traverse the ATF under test.

12. The system of claim 11, wherein the radiation controller controls the radiation source so as to emit a predetermined sequence of radiation signals with progressively increasing intensity.

13. The system of claim 10, wherein the radiation controller controls the radiation source to emit pulse radiation signals.

14. The system of claim 13, wherein the output circuit is configured to compare duty cycle values of pulse signals at the output of the radiation receiver with calibration duty cycle values to determine the condition of the ATF under test.

16. The method of claim 13 further comprising the step of comparing a signal indicative of the opacity with multiple calibration levels to determine the remaining service life of the ATF under test.

17. The method of claim 16 wherein each of the multiple calibration levels is set in response to the radiation passed through the ATF having known length of life.

18. The method of claim 17, wherein the ATF under test is irradiated with infrared radiation to provide consistent indication of the remaining service life for ATF of various types.

19. The method of claim 18, wherein the ATF under test is irradiated with red light to increase the accuracy of determining the remaining service life of ATF of a particular type as a function of the measured opacity.

15. A method of determining the remaining service life of ATF, comprising the steps of:

emitting radiation in a direction of ATF under test contained in a disposable container,

measuring the opacity of the ATF based on the radiation passed through the ATF, and

determining the remaining service life of the ATF as a function of the measured opacity.