US3858097A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure-sensing capacitor
Assignee: Bendix Corp
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Filing: 1973-12-26
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Granted: 1974-12-31
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Expires: 1993-12-26
Abstract
Abstract A capacitance type pressure transducer which avoids errors due to changes in temperature has a pressure responsive capacitor and a fixed reference capacitor connected in a circuit to provide an output proportional to the ratio of the capacitances as a function of pressure. Since both capacitors are subjected to the same temperature changes any variations in capacitance due to temperature is cancelled out in the ratio.
Inventors
- 👤 W Polye
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:58
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/04; G; G01; G01L; G01L9/00; G01L9/0082; G01L9/0086; G01L9/12; G01L9/125
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
106 words
A pressure transducer of the capacitance type comprising a hollow body having spaced opposing walls of insulating material supported at their edges, the portions of the walls spaced from the edges being deflectable relative to one another in response to changes in pressure and the portions of the walls adjacent the edges being substantially nondeflectable relative to one another with changes in pressure, electrical conducting means on opposing surfaces of the deflectable portions of said walls forming the plates of a pressure sensitive capacitor, and electrical conducting means on opposing surfaces of the substantially nondeflectable portions of said walls forming the plates of a reference capacitor.
Claim 2
Dependent Claim
106 words
A pressure transducer of the capacitance type comprising a hollow body having spaced opposing walls of insulating material supported at their edges, the portions of the walls spaced from the edges being deflectable relative to one another in response to changes in pressure and the portions of the walls adjacent the edges being substantially nondeflectable relative to one another with changes in pressure, electrical conducting means on opposing surfaces of the deflectable portions of said walls forming the plates of a pressure sensitive capacitor, and electrical conducting means on opposing surfaces of the substantially nondeflectable portions of said walls forming the plates of a reference capacitor.
Claim 3
Dependent Claim
38 words
A pressure transducer as described in claim 1 adapted for use in an environment which changes temperature over a substantially wide range, the capacitors being formed and arranged to change capacitance corresponding amounts due to changes in temperature.
Claim 4
Dependent Claim
29 words
A pressure transducer as described in claim 1 having means for connecting the capacitor plates in a circuit to provide an output proportional to the ratio of the capacitors.
Claim 5
Dependent Claim
17 words
A pressure transducer as described in claim 1 in which the hollow body is made of quartz.
Claim 6
Dependent Claim
27 words
A pressure transducer of the kind described in claim 1 in which the body is circular and the spaced opposing walls are supported circumferentially at their edges.
Claim 7
Dependent Claim
23 words
A pressure transducer as described in claim 1 in which the capacitances of the pressure sensitive capacitor and the reference capacitor are equal.
Claim 8
Dependent Claim
108 words
A pressure transducer of the capacitance type comprising a hollow circular body having spaced opposing walls supported circumferentially at their edges, the portions of the walls spaced from the edges being deflectable relative to one another in response to changes in pressure and the portions of the walls adjacent the edges beIng substantially nondeflectable relative to one another with changes in pressure, circular electrical conducting means positioned centrally on the deflectable portions of said walls forming the plates of a pressure sensitive capacitor, and annular electrical conducting means positioned adjacent the edges on the substantially non deflectable portions of said walls forming the plates of a reference capacitor.
Claim 9
Dependent Claim
108 words
A pressure transducer of the capacitance type comprising a hollow circular body having spaced opposing walls supported circumferentially at their edges, the portions of the walls spaced from the edges being deflectable relative to one another in response to changes in pressure and the portions of the walls adjacent the edges beIng substantially nondeflectable relative to one another with changes in pressure, circular electrical conducting means positioned centrally on the deflectable portions of said walls forming the plates of a pressure sensitive capacitor, and annular electrical conducting means positioned adjacent the edges on the substantially non deflectable portions of said walls forming the plates of a reference capacitor.
References Cited (Backward Citations)
US2916279A
Cited
DE2021479A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |