US3702957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable capacitance displacement transducers
Assignee: Individual
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Filing: 1971-01-19
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Granted: 1972-11-14
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Expires: 1991-01-19
Abstract
Abstract A capacitive position transducer in which a movable element controls the ratio of the capacitances of two capacitors. The movable element is a screen which, in the preferred embodiments, moves between the plates of one of the capacitors thereby changing its capacitance. The ratio of said capacitances is used to provide an indication of the position of the screen and hence of the movable element.
Inventors
- 👤 Peter Caleb Frederi Wolfendale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:48
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/24; G01D5/2403
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
114 words
Position transducer means of the variable capacitance type, comprising support means; first and second capacitor electrodes connected with said support means in linearly arranged axially spaced relation; a common capacitor electrode connected with said support means in uniformly spaced relation relative to said first and second capacitor electrodes, thereby to define first and second capacitances between said common electrode and said first and second electrodes, respectively; and screen means connected with said support means for movement in the space between said first and common electrodes to vary only said first capacitance, whereby the ratio of the first and second capacitance varies in accordance with the displacement of said screen means relative to said housing.
Claim 2
Dependent Claim
114 words
Position transducer means of the variable capacitance type, comprising support means; first and second capacitor electrodes connected with said support means in linearly arranged axially spaced relation; a common capacitor electrode connected with said support means in uniformly spaced relation relative to said first and second capacitor electrodes, thereby to define first and second capacitances between said common electrode and said first and second electrodes, respectively; and screen means connected with said support means for movement in the space between said first and common electrodes to vary only said first capacitance, whereby the ratio of the first and second capacitance varies in accordance with the displacement of said screen means relative to said housing.
Claim 3
Dependent Claim
62 words
Apparatus as defined in claim 1, wherein said first and second electrodes are annular, colinearly arranged and axially spaced; wherein said common electrode is generally cylindrical and extends coaxially in concentrically spaced relation within said first and second electrodes; and further wherein said screen includes an annular portion that extends coaxially in concentrically spaced relation solely between said common and first electrodes.
Claim 4
Dependent Claim
39 words
Apparatus as defined in claim 2, and further including capacitance adjusting screw means connected for axial adjustment within, and in a direction parallel with the axis of, said second electrode, thereby to adjust the value of said fixed capacitance.
Claim 5
Dependent Claim
40 words
Apparatus as defined in claim 3, wherein said common electrode contains at one end a longitudinal bore that extends within said second electrode, and further wherein said adjusting screw means is threadably connected within, and longitudinally movable of, said bore.
Claim 6
Dependent Claim
36 words
Apparatus as defined in claim 3, wherein the portion of said common electrode arranged within said second electrode contains at least one radially extending through bore that communicates at its inner end with said longitudinal bore.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-14 | 1976-05-15 | 1976-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-14 | 1980-05-15 | 1980-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-14 | 1984-05-15 | 1984-11-14 | $7700.00 | Window Closed / Lapsed |