Patent US4107640A successfully refreshed from Google Patents.
US4107640A
Expired / Lapsed
US
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Current limiting element for preventing electrical overcurrent
Assignee: Tokai Rika Co Ltd
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Filing: 1976-11-19
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Granted: 1978-08-15
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Expires: 1996-11-19
Abstract
Abstract A current limiting element for preventing electrical overcurrent including a principal current conducting member made of a low resistance conductive elastomer having a high coefficient of thermal expansion and having a flattened cross-sectional shape and a heating/heat insulating member which consists of a high resistance conductive elastomer or a resistive coating surrounding the circumference of the conducting member.
Inventors
- 👤 Chihiro Asano
- 👤 Shigeyuki Hikita
- 👤 Kunio Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:35
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/13
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
60 words
A current limiting element comprising: a principal current conducting member made from a low resistance conductive elastomer having a high positive coefficient of thermal expansion, said principal conducting member having a flattened cross-sectional shape; a heating/heat insulating member having a high resistance surrounding the circumference of said conducting member; and an indirect heating element disposed adjacent said heating/heat insulating member.
Claim 2
Dependent Claim
60 words
A current limiting element comprising: a principal current conducting member made from a low resistance conductive elastomer having a high positive coefficient of thermal expansion, said principal conducting member having a flattened cross-sectional shape; a heating/heat insulating member having a high resistance surrounding the circumference of said conducting member; and an indirect heating element disposed adjacent said heating/heat insulating member.
Claim 3
Dependent Claim
33 words
A current limiting element according to claim 1 wherein said principal current conducting member is made from silicone rubber mixed with conductive particles selected from the group consisting of gold, silver and platinum.
Claim 4
Dependent Claim
62 words
A current limiting element comprising: a principal current conducting member made from a low resistance conductive elastomer having a high positive coefficient of thermal expansion, said principal conducting member having a flattened cross-sectional shape; and a heating/heat insulating member having a high resistance surrounding the circumference of said conducting member, said heating/heat insulating member being made of a high resistance conductive elastomer.
Claim 5
Dependent Claim
62 words
A current limiting element comprising: a principal current conducting member made from a low resistance conductive elastomer having a high positive coefficient of thermal expansion, said principal conducting member having a flattened cross-sectional shape; and a heating/heat insulating member having a high resistance surrounding the circumference of said conducting member, said heating/heat insulating member being made of a high resistance conductive elastomer.
Claim 6
Dependent Claim
18 words
A current limiting element according to claim 1 wherein said heating/heat insulating member is a high resistance coating.
Claim 7
Dependent Claim
24 words
A current limiting element according to claim 4 wherein said high resistance coating comprising carbon black deposited directly on said principal current conducting member.
Claim 8
Dependent Claim
28 words
A current limiting element according to claim 1 further comprising a heat detecting element in series with said indirect heating element and continguous with said indirect heating element.
Claim 9
Dependent Claim
16 words
A current limiting element according to claim 6 wherein said heat detecting element is a thermistor.
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) | 1981-08-14 | 1982-02-13 | 1982-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-14 | 1986-02-13 | 1986-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-14 | 1990-02-13 | 1990-08-15 | $7700.00 | Window Closed / Lapsed |