US3912988A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitive detector for an electronic differential pressure transmitter
Assignee: Fischer and Porter Co
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Filing: 1974-02-11
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Granted: 1975-10-14
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Expires: 1994-02-11
Abstract
Abstract An electronic differential pressure transmitter for use with industrial processes to produce an output signal suitable for transmission to a remote station for operating, indicating, recording or control equipment. The transmitter includes a force bar to which an input force is applied, the resultant bar displacement being sensed by a capacitive detector coupled to an electronic circuit yielding a feedback signal proportional to the input force. The detector is formed by two spaced electrodes mounted on a dielectric plate, the gap therebetween being effectively varied by means of an armature movable relative to the electrodes.
Inventors
- 👤 Peter S Levesque
- 👤 Max Gaertner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:51
CPC Classifications
G; G01; G01L; G01L13/00; G01L13/02; G01L13/025; G01L11/00; G01L11/004; G01L11/008; G01L9/00; G01L9/0041; G01L9/0072; G01L9/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
126 words
A displacement-responsive capacitive detector comprising: A. a dielectric plate constituted by borosilicate glass; B. two spaced fixed flat electrodes mounted in a common plane on said plate; C. terminals connected to said electrodes; and D. an electrically-floating planar metal armature parallel to the faces of said electrodes, an air gap existing between said armature and said faces, said armature being movable in response to a displacement force relative to the faces of said electrodes to effectively vary the air gap therebetween, thereby changing the value of capacitance presented at said terminals as a function of displacement; said flat electrodes being metallized on one side of said plate and being constituted by a pair of semi-circular areas whose straight edges are separated by a straight air gap.
Claim 2
Dependent Claim
126 words
A displacement-responsive capacitive detector comprising: A. a dielectric plate constituted by borosilicate glass; B. two spaced fixed flat electrodes mounted in a common plane on said plate; C. terminals connected to said electrodes; and D. an electrically-floating planar metal armature parallel to the faces of said electrodes, an air gap existing between said armature and said faces, said armature being movable in response to a displacement force relative to the faces of said electrodes to effectively vary the air gap therebetween, thereby changing the value of capacitance presented at said terminals as a function of displacement; said flat electrodes being metallized on one side of said plate and being constituted by a pair of semi-circular areas whose straight edges are separated by a straight air gap.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |