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US4418571A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid level measuring system

Assignee: Veeder Industries Inc
•
Filing: 1981-12-18
•
Granted: 1983-12-06
•
Expires: 2001-12-18
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Abstract

Abstract A liquid level measuring device has an outer capacitance tube, an imperforate glass tube coaxially within the outer tube defining a capacitor annulus between them, and an inner capacitor sleeve coaxially within the glass tube and having separate longitudinally extending sleeve sections. The separate sleeve sections cooperate with the outer capacitance tube to form a plurality of capacitor sections each having a separately measurable value which varies between dry minimum and submerged maximum.

Inventors

  • 👤 Einar Asmundsson
  • 👤 Robert P. Hart
  • 👤 Donald W. Fleischer

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 17:59
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/26; G01F23/263

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 107 words
In a liquid level measurement device having an elongated capacitance probe with a succession of a plurality of longitudinally extending capacitor sections, each having a separately measurable capacitance value which varies between dry minimum and submerged maximum values thereof, the improvement wherein the capacitance probe comprises an outer capacitance tube, an imperforate glass tube mounted generally coaxially within the outer capacitance tube to define a capacitor annulus therebetween, and an inner capacitor sleeve mounted coaxially within the glass tube and having a succession of a plurality of separate, longitudinally extending capacitance sleeve sections cooperating with the outer capacitance tube to form said plurality of capacitor sections respectively.
Claim 2
Dependent Claim 107 words
In a liquid level measurement device having an elongated capacitance probe with a succession of a plurality of longitudinally extending capacitor sections, each having a separately measurable capacitance value which varies between dry minimum and submerged maximum values thereof, the improvement wherein the capacitance probe comprises an outer capacitance tube, an imperforate glass tube mounted generally coaxially within the outer capacitance tube to define a capacitor annulus therebetween, and an inner capacitor sleeve mounted coaxially within the glass tube and having a succession of a plurality of separate, longitudinally extending capacitance sleeve sections cooperating with the outer capacitance tube to form said plurality of capacitor sections respectively.
Claim 3
Dependent Claim 28 words
A liquid level measurement device according to claim 1, further comprising an outer generally coaxial tubular shroud surrounding the outer capacitor tube to define a second annulus therebetween.
Claim 4
Dependent Claim 43 words
A liquid level measurement device according to claim 2, further comprising a tangential inlet opening at the lower end of the capacitance probe for conducting liquid tangentially into said second annulus to provide a centrifuge for separating any extraneous material from the liquid.
Claim 5
Dependent Claim 34 words
A liquid level measurement device according to claim 3, wherein the outer capacitor tube has an inlet opening above said tangential inlet opening for conducting liquid from said second annulus to the capacitor annulus.
Claim 6
Dependent Claim 47 words
A liquid level measurement device according to claim 2 or 3 wherein the outer tubular shroud and outer capacitor tube each have a plurality of axially spaced apertures to conduct liquid to and from said second annulus and between said second annulus and the capacitor annulus respectively.
Claim 7
Dependent Claim 46 words
A liquid level measurement device according to claim 5 wherein the axially spaced apertures in each said outer shroud and outer capacitor tube are angularly staggered and wherein the aperture in the outer capacitor tube are angularly spaced from the adjacent apertures in the outer shroud.

References Cited (Backward Citations)

US2754457A Cited
US2941403A Cited
US3228245A Cited
US4296472A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-12-05 1987-06-06 1987-12-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-12-05 1991-06-06 1991-12-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-12-05 1995-06-06 1995-12-06 $7700.00 Window Closed / Lapsed

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