US3753200A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Short circuit proof level sensor
Assignee: MERITAPE Inc
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Filing: 1972-05-18
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Granted: 1973-08-14
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Expires: 1992-05-18
Abstract
Abstract An elongated continuous sensor adapted for disposition within a fluent material for monitoring the level thereof and operative even in the presence of a short circuit in the electrical winding of such sensor. A resistance winding helically wound around and insulated from a base strip includes portions confronting a surface having discrete conductive areas, each adjacent pair of areas being bridged by a respective turn of the helical winding. In the presence of surrounding pressure caused by the fluent material mass, the bridging turns within the material mass are deflected into engagement with the underlying conductive areas such that the discrete conductive areas within the material mass are effectively interconnected to short circuit that portion of the snesor submerged within the mass, the resistance of the helical winding above the material mass being a direct measure of material level. A short circuit of one or more adjacent turns of the helical winding to the underlying conductive areas causes the short circuiting of only those turns with the result that the sensor remains operative with only a slight error introduced by the number of turns short circuited.
Inventors
- 👤 J Niejadlik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:26
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/14; G01F23/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
115 words
A level sensor comprising: an elongated base strip; a plurality of discrete conductive areas insulatingly disposed on one surface thereof extending in spaced apart regular relationship along the length of said base strip; a resistance element helically wound around said base strip and having portions bridging the confronting ends of adjacent ones of said discrete conductive areas and spaced therefrom in the absence of surrounding pressure; means for electrically connecting one end of said resistance element to a first sensor therminal; means for electrically connecting the opposite end of said resistance element to a second sensor terminal; and a flexible jacket surrounding said base strip and said helical winding and being sensitive to surrounding pressure.
Claim 2
Dependent Claim
115 words
A level sensor comprising: an elongated base strip; a plurality of discrete conductive areas insulatingly disposed on one surface thereof extending in spaced apart regular relationship along the length of said base strip; a resistance element helically wound around said base strip and having portions bridging the confronting ends of adjacent ones of said discrete conductive areas and spaced therefrom in the absence of surrounding pressure; means for electrically connecting one end of said resistance element to a first sensor therminal; means for electrically connecting the opposite end of said resistance element to a second sensor terminal; and a flexible jacket surrounding said base strip and said helical winding and being sensitive to surrounding pressure.
Claim 3
Dependent Claim
64 words
The level sensor according to claim 1 wherein said base strip is of electrically conductive material; and wherein said sensor further includes an insulative material partially surrounding said base strip to define an uninsulated opening along the length of one side of said base strip containing said discrete conductive areas, said helical element being insulated from said base strip by said interposed insulative material.
Claim 4
Dependent Claim
65 words
The level sensor according to claim 1 wherein said base strip is of electrically insulative material; and wherein said means for connecting one end of said resistance element to a first sensor terminal includes a conductive path provided on the surface of said base strip opposite to the surface containing said discrete conductive areas and extending substantially along the full length of said base strip.
Claim 5
Dependent Claim
64 words
The level sensor according to claim 1 wherein said base strip is of electrically insulative material and includes first and second raised portions extending along opposite edges of the surface of said base strip containing said discrete conductive areas, the portions of said resistance element bridging said confronting discrete conductive areas being spaced therefrom by said raised portions in the absence of surrounding pressure.
Claim 6
Dependent Claim
168 words
An elongated level sensor adapted for disposition within a fluent material mass and operative to provide an output indication continuously representative of the level of said material mass, said level sensor comprising: an elongated base strip; a resistance element helically wound around said base strip substantially along the full length thereof; a plurality of discrete conductive areas insulatingly disposed on a surface of said base strip in regular spaced apart relationship along the length thereof, each adjacent pair of conductive areas being bridged by a turn of said helical element; the turns of said helical element being spaced from said discrete conductive areas in the absence of surrounding pressure and being adapted to engage the underlying portions of said conductive areas in the presence of surrounding pressure caused by said fluent material mass; means for electrically connecting respective opposite ends of said resistance element to first and second sensor terminals; and a flexible jacket surrounding said base strip and said helical element and being sensitive to surrounding pressure.
Claim 7
Dependent Claim
168 words
An elongated level sensor adapted for disposition within a fluent material mass and operative to provide an output indication continuously representative of the level of said material mass, said level sensor comprising: an elongated base strip; a resistance element helically wound around said base strip substantially along the full length thereof; a plurality of discrete conductive areas insulatingly disposed on a surface of said base strip in regular spaced apart relationship along the length thereof, each adjacent pair of conductive areas being bridged by a turn of said helical element; the turns of said helical element being spaced from said discrete conductive areas in the absence of surrounding pressure and being adapted to engage the underlying portions of said conductive areas in the presence of surrounding pressure caused by said fluent material mass; means for electrically connecting respective opposite ends of said resistance element to first and second sensor terminals; and a flexible jacket surrounding said base strip and said helical element and being sensitive to surrounding pressure.
Claim 8
Dependent Claim
141 words
A level sensor adapted for disposition in a fluent material mass and comprising: an electrically conductive base strip; an insulative material partially surrounding said base strip to define an uninsulated opening along the length of one side of said base strip; a plurality of discrete conductive areas disposed on and insulated from said uninsulated opening of said base strip; a resistance wire helically wound around said insulated base strip and having portions bridging confronting ends of adjacent ones of said conductive areas and spaced therefrom in the absence of surrounding pressure; a flexible jacket surrounding said base strip and said helical wire and being sensitive to surrounding pressure; and means connecting the lower end of said helical winding to said base strip; said base strip and the upper end of said helical wire being adapted for connection to level monitoring circuitry.
Claim 9
Dependent Claim
141 words
A level sensor adapted for disposition in a fluent material mass and comprising: an electrically conductive base strip; an insulative material partially surrounding said base strip to define an uninsulated opening along the length of one side of said base strip; a plurality of discrete conductive areas disposed on and insulated from said uninsulated opening of said base strip; a resistance wire helically wound around said insulated base strip and having portions bridging confronting ends of adjacent ones of said conductive areas and spaced therefrom in the absence of surrounding pressure; a flexible jacket surrounding said base strip and said helical wire and being sensitive to surrounding pressure; and means connecting the lower end of said helical winding to said base strip; said base strip and the upper end of said helical wire being adapted for connection to level monitoring circuitry.
Claim 10
Dependent Claim
46 words
The level sensor according to claim 6 wherein said plurality of discrete conductive areas are contained on a strip of insulating material supported on said one side of said base strip, with said conductive areas in confronting relation to said bridging portions of said resistance wire.
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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |