US5227946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical device comprising a PTC conductive polymer
Assignee: Tyco International Ltd Bermuda
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Filing: 1992-04-13
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Granted: 1993-07-13
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Expires: 2012-04-13
Abstract
Abstract Conductive polymer PTC compositions have improved properties, especially at voltages of 200 volts or more, if they are very highly cross-linked by means of irradiation, for example to a dosage of at least 50 Mrads, preferably at least 80 Mrads, e.g. 120 to 600 Mrads. The cross-linked compositions are particularly useful in circuit protection devices and layered heaters.
Inventors
- 👤 Stephen M. Jacobs
- 👤 Mary S. McTavish
- 👤 Frank A. Doljack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:03
CPC Classifications
H; H05; H05B; H05B1/00; H05B1/02; H01; H01C; H01C17/00; H01C17/06; H01C17/065; H01C17/06506; H01C17/06573; H01C17/06586; H01C7/00; H01C7/02; H01C7/027
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
59 words
An electrical device which comprises (a) a radiation cross-linked PTC conductive polymer element and (b) two electrodes which can be connected to a power source to cause current to flow through the PTC element, said device when subjected to SEM scanning, showing a maximum difference in voltage between two points separated by 10 microns of less than 3 volts.
Claim 2
Dependent Claim
59 words
An electrical device which comprises (a) a radiation cross-linked PTC conductive polymer element and (b) two electrodes which can be connected to a power source to cause current to flow through the PTC element, said device when subjected to SEM scanning, showing a maximum difference in voltage between two points separated by 10 microns of less than 3 volts.
Claim 3
Dependent Claim
17 words
A device according to claim 1 wherein the maximum difference in voltage is less than 2 volts.
Claim 4
Dependent Claim
17 words
A device according to claim 2 wherein the maximum difference in voltage is less than 1 volt.
Claim 5
Dependent Claim
20 words
A device according to claim 1 which is a circuit protection device having a resistance of less than 50 ohms.
Claim 6
Dependent Claim
34 words
A device according to claim 1 which is a circuit protection device wherein the conductive polymer element comprises a polymeric component and, dispersed in the polymeric component, a particulate conductive filler comprising carbon black.
Claim 7
Dependent Claim
12 words
A device according to claim 5 wherein the polymeric component comprises polyethylene.
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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) | 1996-07-12 | 1997-01-11 | 1997-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-12 | 2001-01-11 | 2001-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-12 | 2005-01-11 | 2005-07-13 | $7700.00 | Window Closed / Lapsed |