Patent US4418571A successfully refreshed from Google Patents.
US4418571A
Expired / Lapsed
US
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Liquid level measuring system
Assignee: Veeder Industries Inc
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Filing: 1981-12-18
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Granted: 1983-12-06
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Expires: 2001-12-18
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 19:18
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)
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 |