US4334148A
Expired / Lapsed
US
⏱️ 0.0 years remaining
PTC Heaters
Assignee: Raychem Corp
•
Filing: 1978-01-16
•
Granted: 1982-06-08
•
Expires: 1998-01-16
Abstract
Abstract A self-regulating electrical heater comprised of a material which exhibits a positive temperature coefficient of resistance. The heater has a generally rectangular cross-section which provides greater thermal stability and reduces the number of hotline failures.
Inventors
- 👤 Andrew J. Kampe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:16
CPC Classifications
H; H01; H01C; H01C1/00; H01C1/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
114 words
A self-regulating PTC strip heater comprising two parallel spaced-apart rod-like electrodes embedded in and enclosed by a web of PTC material which consists of an extruded homogenous mixture comprising carbon black dispersed in a polymeric material, said web of PTC material having a generally rectangular cross-section and having a generally retangular cross-section between the electrodes and having a substantially constant thickness t, said thickness t being greater than the maximum dimension of the electrodes in the same direction, and said electrodes being spaced apart by a distance 1 such that the ratio 1/t is from about 3/1 to 5/1, the current path between said electrodes always being exclusively in said web of PTC material.
Claim 2
Dependent Claim
114 words
A self-regulating PTC strip heater comprising two parallel spaced-apart rod-like electrodes embedded in and enclosed by a web of PTC material which consists of an extruded homogenous mixture comprising carbon black dispersed in a polymeric material, said web of PTC material having a generally rectangular cross-section and having a generally retangular cross-section between the electrodes and having a substantially constant thickness t, said thickness t being greater than the maximum dimension of the electrodes in the same direction, and said electrodes being spaced apart by a distance 1 such that the ratio 1/t is from about 3/1 to 5/1, the current path between said electrodes always being exclusively in said web of PTC material.
Claim 3
Dependent Claim
113 words
A self-regulating PTC strip heater comprising two parallel spaced-apart rod-like electrodes embedded in and enclosed by a web of PTC material which consists of an extruded homogenous mixture comprising carbon black dispersed in a polymeric material, said web of PTC material having a generally elliptical cross-section and having a generally rectangular cross-section between the electrodes and having a substantially constant thickness t, said thickness t being greater than the maximum dimension of the electrodes in the same direction, and said electrodes being spaced apart by a distance 1 such that the ratio 1/t is about 3/1 to 5/1, the current path between said electrodes always being exclusively in said web of PTC material.
Claim 4
Dependent Claim
113 words
A self-regulating PTC strip heater comprising two parallel spaced-apart rod-like electrodes embedded in and enclosed by a web of PTC material which consists of an extruded homogenous mixture comprising carbon black dispersed in a polymeric material, said web of PTC material having a generally elliptical cross-section and having a generally rectangular cross-section between the electrodes and having a substantially constant thickness t, said thickness t being greater than the maximum dimension of the electrodes in the same direction, and said electrodes being spaced apart by a distance 1 such that the ratio 1/t is about 3/1 to 5/1, the current path between said electrodes always being exclusively in said web of PTC material.
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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) | 1985-06-07 | 1985-12-07 | 1986-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-07 | 1989-12-07 | 1990-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-07 | 1993-12-07 | 1994-06-08 | $7700.00 | Window Closed / Lapsed |