US3553575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitive sensing device having a slidable probe
Assignee: Sonic Engineering Corp
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Filing: 1967-11-27
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Granted: 1971-01-05
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Expires: 1987-11-27
Abstract
Abstract A SENSING DEVICE FOR DETECTING THE POSITION OF AN OBJECT, TYPICALLY THE PRESENCE OF A MEDIUM, SUCH AS A FLUID IN A SIGHT GLASS. A PAIR OF CAPACITOR PLATES IS MOUNTED ADJACENT TO A REFERENCE POSITION, AND THE CAPACITANCE IS AFFECTED BY THE PRESENCE OF THE OBJECT. THE CAPACITOR PLATES ARE INCLUDED AS CIRCUIT ELEMENTS IN AN OSCILLATOR CIRCUIT IN WHICH OSCILLATION IS CONTROLLED BY CAPACITANCE, TYPICALLY SO THAT OSCILLATION OCCURS WHEN THE OBJECT IS PRESENT ADJACENT TO THE CAPACITOR PLATES.
Inventors
- 👤 James E Shea
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:23
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/945; H03K17/955; G; G01; G01F; G01F23/00; G01F23/22; G01F23/26; G01F23/263
Claims Analysis
Total Claims: 0
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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) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |