US4165641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid level sensing means
Assignee: Duracell Inc USA
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Filing: 1975-10-22
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Granted: 1979-08-28
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Expires: 1995-10-22
Abstract
Abstract An inductance element, such as a coil, cooperates with a detector/amplifier circuit to detect the level of a liquid in a container by quenching oscillations in an electrical circuit when the liquid is brought into close proximity to the inductance element.
Inventors
- 👤 Daniel I. Pomerantz
- 👤 Michael Smolin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:28
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
257 words
A sensing means for sensing the level of a liquid comprising: a. a container containing said liquid; b. a coil of wire wound around the outside of a coil former, said coil former disposed in said container; and c. a detector/amplifier circuit connected to said coil of wire, said detector/amplifier circuit in combination with said coil of wire comprising an oscillator circuit to provide electrical oscillations therein, said detector/amplifier circuit including means adjusting the sensitivity of said oscillator circuit such that when a liquid is provided in close proximity to said coil of wire said oscillations are quenched, said detector/amplifier circuit providing an electrical signal to activate at least one device when said oscillations are quenched; d. said detector/amplifier circuit including a transistor, the base of which is connected to a first side of a capacitance means and a first side of a first resistance means, the collector of which is connected to a first side of a second resistance means and to a first side of an inductance means, and the emitter of which is connected to a first electric terminal and a first side of a third resistance means; a second side of said first and second resistance means and a second side of said inductance means connected to a second electric terminal; a second side of said third resistance means connected to a first side of said coil of wire and to a third electric terminal; and a second side of said capacitance means connected to a second side of said coil of wire.
Claim 2
Dependent Claim
257 words
A sensing means for sensing the level of a liquid comprising: a. a container containing said liquid; b. a coil of wire wound around the outside of a coil former, said coil former disposed in said container; and c. a detector/amplifier circuit connected to said coil of wire, said detector/amplifier circuit in combination with said coil of wire comprising an oscillator circuit to provide electrical oscillations therein, said detector/amplifier circuit including means adjusting the sensitivity of said oscillator circuit such that when a liquid is provided in close proximity to said coil of wire said oscillations are quenched, said detector/amplifier circuit providing an electrical signal to activate at least one device when said oscillations are quenched; d. said detector/amplifier circuit including a transistor, the base of which is connected to a first side of a capacitance means and a first side of a first resistance means, the collector of which is connected to a first side of a second resistance means and to a first side of an inductance means, and the emitter of which is connected to a first electric terminal and a first side of a third resistance means; a second side of said first and second resistance means and a second side of said inductance means connected to a second electric terminal; a second side of said third resistance means connected to a first side of said coil of wire and to a third electric terminal; and a second side of said capacitance means connected to a second side of said coil of wire.
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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) | 1982-08-27 | 1983-02-26 | 1983-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-08-27 | 1987-02-26 | 1987-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-08-27 | 1991-02-26 | 1991-08-28 | $7700.00 | Window Closed / Lapsed |