US4101862A
Expired / Lapsed
US
⏱️ 0.0 years remaining
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: 1978-07-18
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Expires: 1996-11-19
Abstract
Abstract A current limiting element for preventing electrical overcurrent manufactured by mixing conductive particles with an elastic insulating material which possesses a positive coefficient of thermal expansion, such that particles are normally in electrical contact with each other, and the elastic material interposed between the particles is caused by heating to expand so that the electric circuit is interrupted.
Inventors
- 👤 Katsuyuki Takagi
- 👤 Chihiro Asano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:33
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/13; H01C7/02; H01C7/027
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
54 words
A current limiting element for preventing electrical overcurrent comprising: a generally elongate principle current conductor means of substantially circular cross-section, said conductor means being made from an elastic insulative material having a positive coefficient of thermal expansion mixed with conductive particles; and a heating/heat insulating member provided about the circumference of said conductor means.
Claim 2
Dependent Claim
54 words
A current limiting element for preventing electrical overcurrent comprising: a generally elongate principle current conductor means of substantially circular cross-section, said conductor means being made from an elastic insulative material having a positive coefficient of thermal expansion mixed with conductive particles; and a heating/heat insulating member provided about the circumference of said conductor means.
Claim 3
Dependent Claim
16 words
A current limiting element according to claim 1 wherein said elastic insulative material is silicone rubber.
Claim 4
Dependent Claim
23 words
A current limiting element according to claim 1 wherein said conductive particles are made from a material which does not corrode or oxidize.
Claim 5
Dependent Claim
22 words
A current limiting element according to claim 3 wherein said particles are selected from the group consisting of gold, silver and platinum.
Claim 6
Dependent Claim
23 words
A current limiting element according to claim 1 wherein said particles are made from a material which forms conductive compounds when it corrodes.
Claim 7
Dependent Claim
26 words
A current limiting element according to claim 1 wherein said particles are made from a conductive material which does not corrode plated onto another conductive material.
Claim 8
Dependent Claim
26 words
A current limiting element according to claim 1 wherein said heating/heat insulating member comprises an insulative elastic material mixed with particles having a high contact resistance.
Claim 9
Dependent Claim
23 words
A current limiting element according to claim 1 wherein said heating/heat insulating member comprises a high resistive material deposited on said conductor means.
Claim 10
Dependent Claim
15 words
A current limiting element according to claim 8 wherein said resistive material is carbon black.
Claim 11
Dependent Claim
27 words
A current limiting element according to claim 1 further comprising an indirect heating means electrically in parallel with said conductor means and adjacent said heating/heat insulating member.
Claim 12
Dependent Claim
37 words
A current limiting element according to claim 10 wherein said current limiting element is disposed within a water tight housing having electrical connection extending through said housing and coupled to said current limiting element at one end.
Claim 13
Dependent Claim
21 words
A current limiting element according to claim 1 wherein said conducting particles are made from a material which does not oxidize.
Claim 14
Dependent Claim
22 words
A current limiting element according to claim 1 wherein said particles are made from material which forms conductive compounds when it oxidizes.
Claim 15
Dependent Claim
26 words
A current limiting element according to claim 1 wherein said particles are made from a conductive material which does not oxidize plated onto another conductive material.
References Cited (Backward Citations)
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US3243753A
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US3238355A
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US3382574A
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US3745507A
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US3793716A
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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) | 1981-07-17 | 1982-01-16 | 1982-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-17 | 1986-01-16 | 1986-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-17 | 1990-01-16 | 1990-07-18 | $7700.00 | Window Closed / Lapsed |