US5148708A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid level sensor which prevents liquid absorption
Assignee: Murata Manufacturing Co Ltd
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Filing: 1991-04-29
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Granted: 1992-09-22
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Expires: 2011-04-29
Abstract
Abstract A liquid level sensor for detecting a level of an electrolyte where: a pair of resistance films are formed on an insulating substrate: a plurality of electrodes are intermittently mounted on the resistance films in the longitudinal direction; the resistance films are soaked in the electrolyte in the vertical direction along the longitudinal direction; the liquid surface is detected from the variation of the resistance value of the resistance films caused by the short-circuiting of pairs of the electrodes in the electrolyte. The exposed surface of the resistance film is covered by a moisture-resistance film. The result is that undesirable change of resistance value of the resistance film caused by being moistened can be reliably prevented.
Inventors
- 👤 Michihiro Murata
- 👤 Akira Kumada
- 👤 Shigeo Yamazaki
- 👤 Kenji Matsuo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:25
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/24; G01F23/241; G01F23/242
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
138 words
A liquid level sensor for detecting the level of a liquid including an electrolyte matter, comprising: (a) an insulating substrate made of plastic thin film; (b) a pair of resistance films disposed in parallel to each other with a predetermined space therebetween on said insulating substrate, said resistance films each having a lengthwise dimension which is larger than a widthwise dimension of said resistance films; (c) a plurality of detecting electrodes mounted intermittently in a longitudinal direction on said resistance films, each electrode including an arm portion extending from said resistance films; (d) lead electrodes mounted at one end of said resistance films, respectively; and (e) a water-proof film for covering an exposed surface of said resistance films; wherein the resistance between said lead electrodes, upon application of a voltage, depends on the liquid level of the electrolyte.
Claim 2
Dependent Claim
138 words
A liquid level sensor for detecting the level of a liquid including an electrolyte matter, comprising: (a) an insulating substrate made of plastic thin film; (b) a pair of resistance films disposed in parallel to each other with a predetermined space therebetween on said insulating substrate, said resistance films each having a lengthwise dimension which is larger than a widthwise dimension of said resistance films; (c) a plurality of detecting electrodes mounted intermittently in a longitudinal direction on said resistance films, each electrode including an arm portion extending from said resistance films; (d) lead electrodes mounted at one end of said resistance films, respectively; and (e) a water-proof film for covering an exposed surface of said resistance films; wherein the resistance between said lead electrodes, upon application of a voltage, depends on the liquid level of the electrolyte.
Claim 3
Dependent Claim
23 words
A liquid level sensor according to claim 1, wherein said arm portion of each said detecting electrode projects partially from said water-proof film.
Claim 4
Dependent Claim
29 words
A liquid level sensor according to claim 2, wherein each said arm portion extends on a surface of said insulating substrate in a horizontal direction from said resistance films.
Claim 5
Dependent Claim
17 words
A liquid level sensor according to claim 1, wherein water-repellent layers are formed between said detecting electrodes.
Claim 6
Dependent Claim
17 words
A liquid level sensor according to claim 1, wherein said insulating substrate is made of polyethylene-type plastic.
Claim 7
Dependent Claim
150 words
A liquid level sensor for detecting the level of a liquid including an electrolyte matter, comprising: (a) an insulating substrate made of plastic thin film; (b) a pair of resistance films disposed in parallel to each other with a predetermined space therebetween on said insulating substrate, said resistance films each having a lengthwise dimension which is larger than a widthwise dimension of said resistance films; (c) a plurality of detecting electrodes mounted intermittently in a longitudinal direction on said resistance films, each electrode including an arm portion extending from said resistance films; (d) a water-proof film for covering an exposed surface of said resistance films; and (e) a water-proof layer at least for covering said detecting electrodes, a part of each said arm portion remaining uncovered by said water-proof layer; wherein the resistance between said lead electrodes, upon application of a voltage, depends on the liquid level of the electrolyte.
Claim 8
Dependent Claim
150 words
A liquid level sensor for detecting the level of a liquid including an electrolyte matter, comprising: (a) an insulating substrate made of plastic thin film; (b) a pair of resistance films disposed in parallel to each other with a predetermined space therebetween on said insulating substrate, said resistance films each having a lengthwise dimension which is larger than a widthwise dimension of said resistance films; (c) a plurality of detecting electrodes mounted intermittently in a longitudinal direction on said resistance films, each electrode including an arm portion extending from said resistance films; (d) a water-proof film for covering an exposed surface of said resistance films; and (e) a water-proof layer at least for covering said detecting electrodes, a part of each said arm portion remaining uncovered by said water-proof layer; wherein the resistance between said lead electrodes, upon application of a voltage, depends on the liquid level of the electrolyte.
Claim 9
Dependent Claim
23 words
A liquid level sensor according to claim 6, wherein said arm portion of each said detecting electrode projects partially from said water-proof layer.
Claim 10
Dependent Claim
22 words
A liquid level sensor according to claim 7, wherein each said arm portion projects in a horizontal direction from said resistance films.
Claim 11
Dependent Claim
25 words
A liquid level sensor according to claim 6, wherein said water-proof layer has a window for exposing said arm portion in contact with said liquid.
Claim 12
Dependent Claim
135 words
A liquid level sensor for detecting the level of a liquid including an electrolyte matter, comprising: (a) an insulating substrate made of plastic thin film; (b) a pair of resistance films disposed in parallel to each other with a predetermined space therebetween on said insulating substrate, said resistance films each having a lengthwise dimension which is larger than a widthwise dimension of said resistance films; (c) a plurality of detecting electrodes formed intermittently in a longitudinal direction on said resistance films, each electrode including an arm portion extending from said resistance films; (d) lead electrodes mounted at one end of said resistance films, respectively; and (e) a water-proof film for covering an exposed surface of said resistance films; wherein the resistance between said lead electrodes, upon application of a voltage, depends on the liquid level.
Claim 13
Dependent Claim
135 words
A liquid level sensor for detecting the level of a liquid including an electrolyte matter, comprising: (a) an insulating substrate made of plastic thin film; (b) a pair of resistance films disposed in parallel to each other with a predetermined space therebetween on said insulating substrate, said resistance films each having a lengthwise dimension which is larger than a widthwise dimension of said resistance films; (c) a plurality of detecting electrodes formed intermittently in a longitudinal direction on said resistance films, each electrode including an arm portion extending from said resistance films; (d) lead electrodes mounted at one end of said resistance films, respectively; and (e) a water-proof film for covering an exposed surface of said resistance films; wherein the resistance between said lead electrodes, upon application of a voltage, depends on the liquid level.
Claim 14
Dependent Claim
31 words
A liquid level sensor for detecting the level of a liquid according to claim 10, wherein said arm portion of each of said detecting electrodes projects partially from said water-proof film.
Claim 15
Dependent Claim
29 words
A liquid level sensor according to claim 10, wherein each said arm portion extends on a surface of said insulating substrate in a horizontal direction from said resistance films.
Claim 16
Dependent Claim
18 words
A liquid level sensor according to claim 10, wherein, wherein water-repellent layers are formed between said detecting electrodes.
Claim 17
Dependent Claim
17 words
A liquid level sensor according to claim 10, wherein said insulating substrate is made of polyethylene-type plastic.
Claim 18
Dependent Claim
32 words
A liquid level sensor according to claim 10, further comprising a water-proof layer at least for covering said detecting electrodes, a part of said arm portion remaining uncovered by said water-proof layer.
Claim 19
Dependent Claim
121 words
A liquid level sensor for detecting the level of a body fluid, comprising: an insulating substrate; a pair of resistance films disposed in parallel to each other with a predetermined space therebetween on said insulating substrate, said resistance films each having a lengthwise dimension which is larger than a widthwise dimension of said resistance films; a plurality of detecting electrodes formed in a longitudinal direction on said resistance films, each electrode including an arm portion extending from said resistance films; lead electrodes formed at one end of said resistance films, respectively; and a water-proof film for covering an exposed surface of said resistance films; wherein the resistance between said lead electrodes, upon application of a voltage, depends on the liquid level.
Claim 20
Dependent Claim
121 words
A liquid level sensor for detecting the level of a body fluid, comprising: an insulating substrate; a pair of resistance films disposed in parallel to each other with a predetermined space therebetween on said insulating substrate, said resistance films each having a lengthwise dimension which is larger than a widthwise dimension of said resistance films; a plurality of detecting electrodes formed in a longitudinal direction on said resistance films, each electrode including an arm portion extending from said resistance films; lead electrodes formed at one end of said resistance films, respectively; and a water-proof film for covering an exposed surface of said resistance films; wherein the resistance between said lead electrodes, upon application of a voltage, depends on the liquid level.
Claim 21
Dependent Claim
23 words
A liquid level sensor according to claim 16, wherein said arm portion of each said detecting electrode projects partially from said water-proof film.
Claim 22
Dependent Claim
26 words
A liquid level sensor according to claim 16, wherein each said arm portion extends on said insulating substrate in a horizontal direction from said resistance films.
Claim 23
Dependent Claim
17 words
A liquid level sensor according to claim 16, wherein water-repellent layers are formed between said detecting electrodes.
Claim 24
Dependent Claim
17 words
A liquid level sensor according to claim 16, wherein said insulating substrate is made of polyethylene-type plastic.
Claim 25
Dependent Claim
33 words
A liquid level sensor according to claim 16, further comprising a water-proof layer at least for covering said detecting electrodes, a part of each said arm portion remaining uncovered by said water-proof layer.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-09-22 | 1996-03-23 | 1996-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-22 | 2000-03-23 | 2000-09-22 | $3760.00 | Window Closed / Lapsed |
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