US3719939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential pressure transducer
Assignee: Westinghouse Electric Corp
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Filing: 1971-02-09
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Granted: 1973-03-06
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Expires: 1991-02-09
Abstract
Abstract The invention relates to a differential pressure transducer employing two spaced apart flexible diaphragm elements, a deflection responsive electrical transducer, such as a piezoelectric crystal, operatively connected to at least one of the diaphragm elements, and a rigid spacer extending between the adjacent surfaces of the diaphragm elements to assure uniform displacement of the diaphragms in response to differential pressures applied to the remote surfaces of the diaphragm elements. Furthermore the rigid spacer prevents deformations of the diaphragm elements resulting from an increase in static pressure conditions existing at the remote surfaces of the diaphragm elements thereby providing inherent zero balance of the differential pressure transducer.
Inventors
- 👤 F Geil
- 👤 W Dunsworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:30
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/20
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
197 words
A differential pressure assembly for generating an electrical signal indicative of difference in fluid pressure comprising, a pressure responsive assembly means including first and second flexible diaphragm elements positioned in a spaced apart relationship defining an internal volume between adjacent internal surfaces of said first and second diaphragm elements, a deflection responsive piezoelectric crystal transducer means mounted on the internal surface of said first flexible diaphragm element, the thickness of said first flexible diaphragm element being sufficiently large with respect to the thickness of piezoelectric crystal transducer means so as to establish the neutral plane of the combination formed by said first flexible diaphragm and said piezoelectric crystal transducer means in said first flexible diaphragm element, and coupling means inserted within said internal volume to provide mechanical coupling between said first and second diaphragm elements, said coupling means providing like deflection of said first and second flexible diaphragm elements in the amount of deflection and direction of deflection in response to a net difference in fluid pressure present at the external surfaces of said first and second diaphragm elements, said deflection responsive piezoelectric transducer means producing a measurable electrical signal indicative of the difference in fluid pressure.
Claim 2
Dependent Claim
197 words
A differential pressure assembly for generating an electrical signal indicative of difference in fluid pressure comprising, a pressure responsive assembly means including first and second flexible diaphragm elements positioned in a spaced apart relationship defining an internal volume between adjacent internal surfaces of said first and second diaphragm elements, a deflection responsive piezoelectric crystal transducer means mounted on the internal surface of said first flexible diaphragm element, the thickness of said first flexible diaphragm element being sufficiently large with respect to the thickness of piezoelectric crystal transducer means so as to establish the neutral plane of the combination formed by said first flexible diaphragm and said piezoelectric crystal transducer means in said first flexible diaphragm element, and coupling means inserted within said internal volume to provide mechanical coupling between said first and second diaphragm elements, said coupling means providing like deflection of said first and second flexible diaphragm elements in the amount of deflection and direction of deflection in response to a net difference in fluid pressure present at the external surfaces of said first and second diaphragm elements, said deflection responsive piezoelectric transducer means producing a measurable electrical signal indicative of the difference in fluid pressure.
Claim 3
Dependent Claim
197 words
A differential pressure assembly for generating an electrical signal indicative of difference in fluid pressure comprising, a pressure responsive assembly means including first and second flexible diaphragm elements positioned in a spaced apart relationship defining an internal volume between adjacent internal surfaces of said first and second diaphragm elements, a deflection responsive piezoelectric crystal transducer means mounted on the internal surface of said first flexible diaphragm element, the thickness of said first flexible diaphragm element being sufficiently large with respect to the thickness of piezoelectric crystal transducer means so as to establish the neutral plane of the combination formed by said first flexible diaphragm and said piezoelectric crystal transducer means in said first flexible diaphragm element, and coupling means inserted within said internal volume to provide mechanical coupling between said first and second diaphragm elements, said coupling means providing like deflection of said first and second flexible diaphragm elements in the amount of deflection and direction of deflection in response to a net difference in fluid pressure present at the external surfaces of said first and second diaphragm elements, said deflection responsive piezoelectric transducer means producing a measurable electrical signal indicative of the difference in fluid pressure.
Claim 4
Dependent Claim
197 words
A differential pressure assembly for generating an electrical signal indicative of difference in fluid pressure comprising, a pressure responsive assembly means including first and second flexible diaphragm elements positioned in a spaced apart relationship defining an internal volume between adjacent internal surfaces of said first and second diaphragm elements, a deflection responsive piezoelectric crystal transducer means mounted on the internal surface of said first flexible diaphragm element, the thickness of said first flexible diaphragm element being sufficiently large with respect to the thickness of piezoelectric crystal transducer means so as to establish the neutral plane of the combination formed by said first flexible diaphragm and said piezoelectric crystal transducer means in said first flexible diaphragm element, and coupling means inserted within said internal volume to provide mechanical coupling between said first and second diaphragm elements, said coupling means providing like deflection of said first and second flexible diaphragm elements in the amount of deflection and direction of deflection in response to a net difference in fluid pressure present at the external surfaces of said first and second diaphragm elements, said deflection responsive piezoelectric transducer means producing a measurable electrical signal indicative of the difference in fluid pressure.
Claim 5
Dependent Claim
23 words
A differential pressure transducer as claimeD in claim 1 wherein said coupling means is a compliant material which substantially fills said internal volume.
Claim 6
Dependent Claim
44 words
A differential pressure transducer as claimed in claim 1 wherein said coupling means is a relatively rigid spacer positioned between the approximate centers of said first and second flexible diaphragm elements and contacting the internal surfaces of said first and second flexible diaphragm elements.
Claim 7
Dependent Claim
38 words
A differential pressure transducer as claimed in claim 3 wherein the combination of said first and second flexible diaphragm elements and said relatively rigid spacer element establishes differential pressure transducer resonant frequency which is greater than 15 hertz.
Claim 8
Dependent Claim
37 words
A differential pressure transducer assembly as claimed in claim 3 wherein the ratio of the cross sectional area of said piezoelectric crystal disc to the cross sectional area of said relatively rigid spacer is greater than 10:1.
Claim 9
Dependent Claim
93 words
A differential pressure transducer as claimed in claim 1 including a second piezoelectric crystal disc mounted on the internal surface of said second flexible diaphragm element said, an electrical lead means for interconnecting the first and second piezoelectric crystal discs, and electrical circuit means operatively connected to said electrical leads to monitor said electrical signal produced by said electrically interconnected piezoelectric crystal discs as indication of difference of pressure between fluid contacting the external surface of said first flexible diaphragm element and fluid contacting the external surface of said second flexible diaphragm element.
Claim 10
Dependent Claim
57 words
A differential pressure transducer assembly as claimed in claim 1 wherein both faces of the piezoelectric crystal disc are in tension during deflection of said first flexible diaphragm element in one direction, and both faces of said piezoelectric crystal disc are in compression in response to deflection of said first flexible diaphragm element in the opposite direction.
References Cited (Backward Citations)
US3438021A
Cited
US3489997A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-05 | 1976-09-04 | 1977-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-05 | 1980-09-04 | 1981-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-05 | 1984-09-04 | 1985-03-06 | $7700.00 | Window Closed / Lapsed |