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US4165641A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid level sensing means

Assignee: Duracell Inc USA
•
Filing: 1975-10-22
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Granted: 1979-08-28
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Expires: 1995-10-22
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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.

References Cited (Backward Citations)

US1780952A Cited
US2354964A Cited
US3319184A Cited
US3326043A Cited
US3375467A Cited
US3511580A Cited
US3641544A Cited

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

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