Patent US5747689A successfully refreshed from Google Patents.
US5747689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid level sensing system
Assignee: Ford Global Technologies LLC
•
Filing: 1996-12-09
•
Granted: 1998-05-05
•
Expires: 2016-12-09
Abstract
Abstract In one embodiment of the present invention, a method for measuring fluid level use a sensor comprising a first plate having continuous electrically conductive material and a second plate having electrically conductive material disposed in segments, the electrically conductive material of the first plate in opposition to the electrically conductive material of the second plate. The method comprises immersing the sensor in the fluid with at least one segment completely immersed in the fluid and at least one said segment completely out of the fluid. The method also includes sequentially energizing the segments. Further, the method includes detecting times of voltage transitions of a first signal at the first plate, relative to the sequential energizing of the segments, as an indication of fluid level.
Inventors
- 👤 Richard Joseph Hampo
- 👤 Paul Theodore Momcilovich
- 👤 Ross Maxwell Stuntz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:38
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/26; G01F23/263; G01F23/266; G01F23/265; G01F23/268
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
170 words
A method for measuring fluid level using a sensor comprising a first plate having continuous electrically conductive material and a second plate having electrically conductive material disposed in segments, said electrically conductive material of said first plate in opposition to said electrically conductive material of said second plate, said method comprising: immersing said sensor in said fluid with at least one said segment completely immersed in said fluid and at least one said segment completely out of said fluid; sequentially energizing said segments; and detecting times of voltage transitions of a first signal at said first plate, relative to said sequential energizing of said segments, as an indication of said fluid level; wherein said step of detecting times of voltage transitions further comprises eliminating negative-going portions of said first signal to create a positive signal; and wherein said step of detecting times of voltage transitions further comprises inverting said positive signal to create an inverted signal and combining said inverted signal and said first signal to create a bipolar signal.
Claim 2
Independent Claim
170 words
A method for measuring fluid level using a sensor comprising a first plate having continuous electrically conductive material and a second plate having electrically conductive material disposed in segments, said electrically conductive material of said first plate in opposition to said electrically conductive material of said second plate, said method comprising: immersing said sensor in said fluid with at least one said segment completely immersed in said fluid and at least one said segment completely out of said fluid; sequentially energizing said segments; and detecting times of voltage transitions of a first signal at said first plate, relative to said sequential energizing of said segments, as an indication of said fluid level; wherein said step of detecting times of voltage transitions further comprises eliminating negative-going portions of said first signal to create a positive signal; and wherein said step of detecting times of voltage transitions further comprises inverting said positive signal to create an inverted signal and combining said inverted signal and said first signal to create a bipolar signal.
Claim 3
Dependent Claim
32 words
A method as recited in claim 1, wherein said step of detecting times of voltage transitions further comprises filtering said bipolar signal to extract a fundamental frequency component of said bipolar signal.
Claim 4
Dependent Claim
26 words
A method as recited of claim 2, wherein said step of detecting times of voltage transitions further comprises detecting the phase of said fundamental frequency component.
Claim 5
Dependent Claim
21 words
A method as recited in claim 3, further comprising generating a pulse-width-modulated signal having a duty cycle representative of said time.
Claim 6
Dependent Claim
26 words
A method as recited in claim 4, further comprising low-pass filtering said pulse-width-modulated signal to generate an analog signal having an amplitude representative of said time.
Claim 7
Dependent Claim
21 words
A method as recited in claim 1, further comprising generating a pulse-width-modulated signal having a duty cycle representative of said time.
Claim 8
Dependent Claim
26 words
A method as recited in claim 6, further comprising low-pass filtering said pulse-width-modulated signal to generate an analog signal having an amplitude representative of said time.
Claim 9
Dependent Claim
173 words
A fluid level sensing system comprising: a sensor further comprising a first plate having continuous electrically conductive material and a second plate having electrically conductive material disposed in segments, said electrically conductive material of said first plate in opposition to said electrically conductive material of said second plate, said sensor immersed in said fluid with one said segment completely immersed in said fluid and one said segment completely out of said fluid; means for sequentially energizing said segments; and means for detecting times of voltage transitions of a first signal at said first plate, relative to said sequential energizing of said segments, as an indication of said fluid level; wherein said means for detecting times of voltage transitions further comprises means for eliminating negative-going portions of said first signal to create a positive signal; and wherein said means for detecting times of voltage transitions further comprises means for inverting said positive signal to create an inverted signal and means for combining said inverted signal and said first signal to create a bipolar signal.
Claim 10
Dependent Claim
173 words
A fluid level sensing system comprising: a sensor further comprising a first plate having continuous electrically conductive material and a second plate having electrically conductive material disposed in segments, said electrically conductive material of said first plate in opposition to said electrically conductive material of said second plate, said sensor immersed in said fluid with one said segment completely immersed in said fluid and one said segment completely out of said fluid; means for sequentially energizing said segments; and means for detecting times of voltage transitions of a first signal at said first plate, relative to said sequential energizing of said segments, as an indication of said fluid level; wherein said means for detecting times of voltage transitions further comprises means for eliminating negative-going portions of said first signal to create a positive signal; and wherein said means for detecting times of voltage transitions further comprises means for inverting said positive signal to create an inverted signal and means for combining said inverted signal and said first signal to create a bipolar signal.
Claim 11
Dependent Claim
34 words
An apparatus as recited in claim 8, wherein said means for detecting times of voltage transitions further comprises means for filtering said bipolar signal to extract a fundamental frequency component of said bipolar signal.
Claim 12
Dependent Claim
27 words
An apparatus as recited in claim 9, wherein said means for detecting times of voltage transitions further comprises means for detecting the phase of said fundamental component.
Claim 13
Dependent Claim
23 words
An apparatus as recited in claim 10, further comprising means for generating a pulse-width-modulated signal having a duty cycle representative of said time.
Claim 14
Dependent Claim
28 words
An apparatus as recited in claim 11, further comprising means for low-pass filtering said pulse-width-modulated signal to generate an analog signal having an amplitude representative of said time.
Claim 15
Dependent Claim
23 words
An apparatus as recited in claim 8, further comprising means for generating a pulse-width-modulated signal having a duty cycle representative of said time.
Claim 16
Dependent Claim
28 words
An apparatus as recited in claim 13, further comprising means for low-pass filtering said pulse-width-modulated signal to generate an analog signal having an amplitude representative of said time.
References Cited (Backward Citations)
US3343415A
Cited
US3935739A
Cited
US4099167A
Cited
US4553434A
Cited
US4594893A
Cited
US4611489A
Cited
US4676101A
Cited
US5142909A
Cited
US5146783A
Cited
US5052223A
Cited
US5399979A
Cited
US5031453A
Cited
US5103368A
Cited
US5423214A
Cited
US5406843A
Cited
US5437184A
Cited
US5613399A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-04 | 2001-11-03 | 2002-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-04 | 2005-11-03 | 2006-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-04 | 2009-11-03 | 2010-05-05 | $7700.00 | Window Closed / Lapsed |