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US4896099A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of announcing low level of remaining liquid in dropper

Assignee: Toho Plastic Co Ltd
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Filing: 1988-12-14
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Granted: 1990-01-23
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Expires: 2008-12-14
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Abstract

Abstract This invention relates to a method of annoucing a low level of the remaining liquid in a dropper. According to the present invention, two electrodes are attached to the outer surface of a dropper, and a pulse of a stable level is applied to one of these electrodes. The remaining quantity of the liquid in the dropper can be detected automatically with ease by utilizing the variations of the electrostatic capacity occurring between these two electrodes. An annunciator is activated when it receives a signal representative of a low level of the liquid in the dropper, to inform a nurse of the necessity of replacing the dropper.

Inventors

  • 👤 Takeo Suzuki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 10:59
CPC Classifications
G; G08; G08B; G08B21/00; G08B21/18; G08B21/182

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 158 words
A method of announcing a low level of the remaining liquid in a dropper, comprising the steps of: applying a pulse of a stable level to at least one of detecting electrodes attached to an outer surface of a lower portion of a liquid-containing dropper; comparing a level of said pulse passed through an interior of said dropper with a reference pulse level, said reference pulse level being between a level of said pulse passed through said interior of said dropper when said liquid exists therein for defining an electrostatic capacity between said detecting electrodes and that of said pulse passed through said interior of said dropper when a remaining quantity of said liquid in said dropper decreases to such an extent that a significantly reduced electrostatic capacity is defined between said detecting electrodes; and automatically actuating an annunciator when a judgement signal representative of unfavorable results derived from said step of comparing with said reference pulse level.
Claim 2
Independent Claim 158 words
A method of announcing a low level of the remaining liquid in a dropper, comprising the steps of: applying a pulse of a stable level to at least one of detecting electrodes attached to an outer surface of a lower portion of a liquid-containing dropper; comparing a level of said pulse passed through an interior of said dropper with a reference pulse level, said reference pulse level being between a level of said pulse passed through said interior of said dropper when said liquid exists therein for defining an electrostatic capacity between said detecting electrodes and that of said pulse passed through said interior of said dropper when a remaining quantity of said liquid in said dropper decreases to such an extent that a significantly reduced electrostatic capacity is defined between said detecting electrodes; and automatically actuating an annunciator when a judgement signal representative of unfavorable results derived from said step of comparing with said reference pulse level.
Claim 3
Dependent Claim 80 words
The method of announcing a low level of the remaining liquid in a dropper as in claim 1, wherein said step of applying a pulse of a stable level includes the steps of applying a certain level of pulses to an electrode, and obtaining a level of pulses at another electrodes, and wherein said step of comparing with said reference pulse level includes the step of comparing said level of pulses at said another electrode with said reference pulse level.

References Cited (Backward Citations)

US3631437A Cited
US3939360A Cited
US4083038A Cited
US4002996A Cited
US4099167A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-01-22 1993-07-24 1994-01-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-01-22 1997-07-24 1998-01-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-01-22 2001-07-24 2002-01-23 $7700.00 Window Closed / Lapsed

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