Patent US5860980A successfully refreshed from Google Patents.
US3566222A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitive displacement transducer
Assignee: AUTOMATIC SYSTEMS LABORATORIES Ltd
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Filing: 1969-10-15
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Granted: 1971-02-23
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Expires: 1989-10-15
Abstract
Abstract A capacitive position transducer comprising two cylindrical coaxial reference electrodes disposed side by side, and a coaxial cylindrical movable electrode disposed within the reference electrodes for movement along the axis to vary the capacitive couplings between the moving electrode and the respective reference electrodes as functions of position. Flanges at each end of the moving electrode are maintained at ground potential and project towards the reference electrodes to form guard rings. One or more screws of conductive or insulating material project through the guard rings to adjust the capacitive couplings. The reference electrodes are spaced from a housing, and the moving electrodes from a shaft, by three-point bearings formed by sapphire balls.
Inventors
- 👤 Peter Caleb Frederi Wolfendale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:34
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/24; G01D5/2403
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
124 words
A capacitive position transducer comprising first and second capacitor electrodes disposed side by side in line, and a third capacitor electrode disposed facing said first and second electrodes and guided for movement relative to and along the line of said first and second electrodes whereby the capacitive couplings between said third electrode and said first and second electrodes are functions of the position of said third electrode relative to said first and second electrodes, wherein the improvement comprises at least one adjustment member mounted for movement with said third electrode and screw-threaded whereby its position relative to said third electrode can be adjusted, said adjustment member projecting between said first and third electrodes to modify the capacitive coupling between said first and third electrodes.
Claim 2
Dependent Claim
124 words
A capacitive position transducer comprising first and second capacitor electrodes disposed side by side in line, and a third capacitor electrode disposed facing said first and second electrodes and guided for movement relative to and along the line of said first and second electrodes whereby the capacitive couplings between said third electrode and said first and second electrodes are functions of the position of said third electrode relative to said first and second electrodes, wherein the improvement comprises at least one adjustment member mounted for movement with said third electrode and screw-threaded whereby its position relative to said third electrode can be adjusted, said adjustment member projecting between said first and third electrodes to modify the capacitive coupling between said first and third electrodes.
Claim 3
Dependent Claim
54 words
A transducer according to claim 1, and comprising a further adjustment member mounted for movement with said third electrode and screw-threaded whereby its position relative to said third electrode can be adjusted, said further adjustment member projecting between said second and third electrodes to modify the capacitive coupling between said second and third electrodes.
Claim 4
Dependent Claim
34 words
A transducer according to claims 1 and comprising guard electrodes secured relative to said third electrode at respective ends of said third electrode, said adjustment member or members being mounted on said guard electrodes.
Claim 5
Dependent Claim
15 words
A transducer according to claim 1 wherein the or/each said adjustment member is electrically conductive.
Claim 6
Dependent Claim
17 words
A transducer according to claim 1 wherein the or/each said adjustment member is made of dielectric material.
Claim 7
Dependent Claim
100 words
A capacitive position transducer comprising a plurality of first capacitor electrodes disposed side-by-side in line, and a second capacitor electrode disposed facing said first electrodes and guided for movement relative to and along the line of said first electrodes whereby the capacitive couplings between said second electrode and respective ones of said first electrodes are functions of the position of said second electrode relative to said first electrodes, wherein the improvement comprises two guard electrodes mounted for movement with said second electrode at respective ends of said second electrode and projecting transverse to said second electrode towards said first electrodes.
Claim 8
Dependent Claim
100 words
A capacitive position transducer comprising a plurality of first capacitor electrodes disposed side-by-side in line, and a second capacitor electrode disposed facing said first electrodes and guided for movement relative to and along the line of said first electrodes whereby the capacitive couplings between said second electrode and respective ones of said first electrodes are functions of the position of said second electrode relative to said first electrodes, wherein the improvement comprises two guard electrodes mounted for movement with said second electrode at respective ends of said second electrode and projecting transverse to said second electrode towards said first electrodes.
Claim 9
Dependent Claim
161 words
A transducer according to claim 6 wherein said first and second electrodes are cylindrical and coaxial, and said guard electrodes comprise respective flanges projecting transverse to and coaxial with said second electrode. 8. A capacitive position transducer comprising a housing, a plurality of coaxial cylindrical first capacitor electrodes disposed in said housing side by side in line, and a cylindrical second capacitor electrode disposed within and facing said first electrodes and guided for movement relative to and along the line of said first electrodes whereby the capacitive couplings between said second electrodes and respective ones of said first electrodes are functions of the position of said second electrode relative to said first electrodes, wherein the improvement comprises a plurality of spacer members of electrically insulating material disposed at the ends of said first electrodes to space said first electrodes from each other and from said housing, each said spacer member covering a part only of the circumference of said first electrodes.
Claim 10
Dependent Claim
35 words
A transducer according to claim 8 wherein said second electrode is secured to a shaft which is mounted on bearings in said housing and comprising a plurality of further spacer members of electrically insulating material.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-22 | 1974-08-24 | 1975-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-22 | 1978-08-24 | 1979-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-22 | 1982-08-24 | 1983-02-23 | $7700.00 | Window Closed / Lapsed |