US4351192A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid flow velocity sensor using a piezoelectric element
Assignee: Lockheed Martin Corp
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Filing: 1980-12-10
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Granted: 1982-09-28
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Expires: 2000-12-10
Abstract
Abstract A piezoelectric, acoustic vibration detecting element is positioned in a fluid flow to be measured so as to be moved according to the intensity of the fluid flow away from a source of acoustic vibration. As the distance between the acoustic vibration source and the element increases with increasing fluid flow intensity, reducing the acoustic pressure on the element, the magnitude of an electrical output signal produced by the element decreases providing a detectable measurement of the change in the fluid flow intensity.
Inventors
- 👤 Minoru Toda
- 👤 Susumu Osaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:51
CPC Classifications
G; G01; G01P; G01P5/00; G01P5/24; G01F; G01F1/00; G01F1/05; G01F1/20; G01F1/28; G01P5/02; G01P5/04; Y; Y10; Y10S; Y10S73/00; Y10S73/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
137 words
In combination, a first piezoelectric element driven from a source of alternating current to propagate an acoustic vibration of a frequency determined according to the frequency of said source, a second piezoelectric element sensitive to said acoustic vibration to produce an electrical output signal according to the acoustic pressure thereon from said vibration, means for mounting said elements in close proximity to one another with said second element mounted in a fluid flow to be measured and movable away from said first element according to the intensity of said fluid flow, said second element being arranged to produce said output signal with decreasing magnitude as the intensity of said fluid flow increases thereby increasing the spacing between said elements, and means for detecting said output signal and providing an indication of the magnitude of said output signal.
Claim 2
Dependent Claim
137 words
In combination, a first piezoelectric element driven from a source of alternating current to propagate an acoustic vibration of a frequency determined according to the frequency of said source, a second piezoelectric element sensitive to said acoustic vibration to produce an electrical output signal according to the acoustic pressure thereon from said vibration, means for mounting said elements in close proximity to one another with said second element mounted in a fluid flow to be measured and movable away from said first element according to the intensity of said fluid flow, said second element being arranged to produce said output signal with decreasing magnitude as the intensity of said fluid flow increases thereby increasing the spacing between said elements, and means for detecting said output signal and providing an indication of the magnitude of said output signal.
References Cited (Backward Citations)
US2985018A
Cited
US2935872A
Cited
US3140612A
Cited
US3452594A
Cited
US3508623A
Cited
GB1309702A
Cited
US3857277A
Cited
US3955415A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-09-27 | 1986-03-29 | 1986-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-27 | 1990-03-29 | 1990-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-27 | 1994-03-29 | 1994-09-28 | $7700.00 | Window Closed / Lapsed |