US3703693A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid level sensing system
Assignee: 630289 ONTARIO Ltd
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Filing: 1971-04-01
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Granted: 1972-11-21
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Expires: 1991-04-01
Abstract
Abstract For detecting a level of a liquid in a container, an element is mounted in a container so as to extend along an area corresponding to the location where liquid depth is to be detected. That element is formed of a material having a ''''memory'''' which is actuated when the material is subjected to a predetermined temperature, to cause the material to change its shape and therefore alter the effective length of the element. Heat is provided to the element, as by causing an electrical current to pass therethrough, in such an amount as to cause said element to be heated to said predetermined temperature when said element is enveloped by air or some other fluid of relatively low heat-dissipating characteristic, but the liquid of the level of which is to be sensed has a relatively high heat-dissipating characteristic such that the liquid-enveloped sections of the element will not be raised to said predetermined temperature. It is only when a given length of said element is exposed to air or other fluid, thus causing that length to exceed said predetermined temperature, that sufficient force is developed to actuate an appropriate work means such as a switch controlling an alarm system or the like.
Inventors
- 👤 Robert N Levinn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:31
CPC Classifications
F; F01; F01P; F01P11/00; F01P11/14; G; G01; G01F; G01F23/00; G01F23/22; G01F23/24; G01F23/246; G01F23/247; H; H01; H01H; H01H61/00; H01H61/01; H01H61/0107; H01H35/00; H01H35/18; H01H35/183; Y; Y10; Y10T; Y10T137/00; Y10T137/7287
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
381 words
In combination with a container having bottom and side walls defining a chamber in which a given liquid is adapted to be received, means for detecting a level of liquid in said chamber comprising an elongated element formed of material having the characteristic that sections along its length, when subjected to a temperature below a predetermined temperature, will tend to retain their given configuration but when subjected to said predetermined temperature will tend to change their configuration from said given configuration to a different configuration, moUnting means operatively connected between said element and said container and active to mount said element within said container in an orientation extending in its said given configuration generally upwardly relative to said bottom wall along a portion of the depth of said chamber where liquid level is to be sensed, the length of said element extending over at least a substantial portion of the depth of said container and over that portion of said depth where the level of said liquid may vary, a part of the length of said element being immersed in said liquid for substantially all expected levels thereof, means for providing heat to said element in an amount insufficient to raise the temperature of a section of said element above said predetermined temperature if said section is subjected to heatdissipating conditions characteristic of being enveloped in said given liquid but in an amount sufficient to raise the temperature of said section above said predetermined temperature if said section is subjected to heat-dissipating conditions characteristic of being enveloped in a substance having a heatdissipating characteristic significantly different from that of said given liquid, work means effective when actuated to perform a work operation appropriate to the detection of a predetermined liquid level in said chamber, said work means comprising a part movable between first and second positions corresponding respectively to actuated and de-actuated conditions of said work means, and a mechanical connection between said part and said element, and means biasing said part to one of said positions, said element moving said part to the other of said positions when the force exerted by sections of said element tending to change their configuration from their given configuration to their different configuration exceeds the force exerted on said part by said biasing means.
Claim 2
Dependent Claim
381 words
In combination with a container having bottom and side walls defining a chamber in which a given liquid is adapted to be received, means for detecting a level of liquid in said chamber comprising an elongated element formed of material having the characteristic that sections along its length, when subjected to a temperature below a predetermined temperature, will tend to retain their given configuration but when subjected to said predetermined temperature will tend to change their configuration from said given configuration to a different configuration, moUnting means operatively connected between said element and said container and active to mount said element within said container in an orientation extending in its said given configuration generally upwardly relative to said bottom wall along a portion of the depth of said chamber where liquid level is to be sensed, the length of said element extending over at least a substantial portion of the depth of said container and over that portion of said depth where the level of said liquid may vary, a part of the length of said element being immersed in said liquid for substantially all expected levels thereof, means for providing heat to said element in an amount insufficient to raise the temperature of a section of said element above said predetermined temperature if said section is subjected to heatdissipating conditions characteristic of being enveloped in said given liquid but in an amount sufficient to raise the temperature of said section above said predetermined temperature if said section is subjected to heat-dissipating conditions characteristic of being enveloped in a substance having a heatdissipating characteristic significantly different from that of said given liquid, work means effective when actuated to perform a work operation appropriate to the detection of a predetermined liquid level in said chamber, said work means comprising a part movable between first and second positions corresponding respectively to actuated and de-actuated conditions of said work means, and a mechanical connection between said part and said element, and means biasing said part to one of said positions, said element moving said part to the other of said positions when the force exerted by sections of said element tending to change their configuration from their given configuration to their different configuration exceeds the force exerted on said part by said biasing means.
Claim 3
Dependent Claim
381 words
In combination with a container having bottom and side walls defining a chamber in which a given liquid is adapted to be received, means for detecting a level of liquid in said chamber comprising an elongated element formed of material having the characteristic that sections along its length, when subjected to a temperature below a predetermined temperature, will tend to retain their given configuration but when subjected to said predetermined temperature will tend to change their configuration from said given configuration to a different configuration, moUnting means operatively connected between said element and said container and active to mount said element within said container in an orientation extending in its said given configuration generally upwardly relative to said bottom wall along a portion of the depth of said chamber where liquid level is to be sensed, the length of said element extending over at least a substantial portion of the depth of said container and over that portion of said depth where the level of said liquid may vary, a part of the length of said element being immersed in said liquid for substantially all expected levels thereof, means for providing heat to said element in an amount insufficient to raise the temperature of a section of said element above said predetermined temperature if said section is subjected to heat-dissipating conditions characteristic of being enveloped in said given liquid but in an amount sufficient to raise the temperature of said section above said predetermined temperature if said section is subjected to heat-dissipating conditions characteristic of being enveloped in a substance having a heat-dissipating characteristic significantly different from that of said given liquid, work means effective when actuated to perform a work operation appropriate to the detection of a predetermined liquid level in said chamber, said work means comprising a part movable between first and second positions corresponding respectively to actuated and de-actuated conditions of said work means, and a mechanical connection between said part and said element, and means biasing said part to one of said positions, said element moving said part to the other of said positions when the force exerted by sections of said element tending to change their configuration from their given configuration to their different configuration exceeds the force exerted on said part by said biasing means.
Claim 4
Dependent Claim
381 words
In combination with a container having bottom and side walls defining a chamber in which a given liquid is adapted to be received, means for detecting a level of liquid in said chamber comprising an elongated element formed of material having the characteristic that sections along its length, when subjected to a temperature below a predetermined temperature, will tend to retain their given configuration but when subjected to said predetermined temperature will tend to change their configuration from said given configuration to a different configuration, moUnting means operatively connected between said element and said container and active to mount said element within said container in an orientation extending in its said given configuration generally upwardly relative to said bottom wall along a portion of the depth of said chamber where liquid level is to be sensed, the length of said element extending over at least a substantial portion of the depth of said container and over that portion of said depth where the level of said liquid may vary, a part of the length of said element being immersed in said liquid for substantially all expected levels thereof, means for providing heat to said element in an amount insufficient to raise the temperature of a section of said element above said predetermined temperature if said section is subjected to heat-dissipating conditions characteristic of being enveloped in said given liquid but in an amount sufficient to raise the temperature of said section above said predetermined temperature if said section is subjected to heat-dissipating conditions characteristic of being enveloped in a substance having a heat-dissipating characteristic significantly different from that of said given liquid, work means effective when actuated to perform a work operation appropriate to the detection of a predetermined liquid level in said chamber, said work means comprising a part movable between first and second positions corresponding respectively to actuated and de-actuated conditions of said work means, and a mechanical connection between said part and said element, and means biasing said part to one of said positions, said element moving said part to the other of said positions when the force exerted by sections of said element tending to change their configuration from their given configuration to their different configuration exceeds the force exerted on said part by said biasing means.
Claim 5
Dependent Claim
38 words
The combination of claim 1, in which said element is electrically conductive, electrical connections being provided to spaced points along said element, said heat-providing means comprising means for passing an electrical current through said element via said connections.
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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) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |