Patent US3646322A successfully refreshed from Google Patents.
US3646322A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric resistance heating cable
Assignee: US Philips Corp
•
Filing: 1971-01-05
•
Granted: 1972-02-29
•
Expires: 1991-01-05
Abstract
Abstract An electric resistance heating cable having alternating sectors of different temperature during use obtained by winding a heating wire having sectors of comparatively high- and comparatively lowelectric resistances on a core of an electrically insulating material and by enveloping the assembly with an electrically insulating covering.
Inventors
- 👤 Bernardus Willebrordu Speekman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:36
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/40; H05B3/54; H05B3/56
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
93 words
An electric redistance heating cable comprising a flexible core of electrically insulating material, a heating wire wound helically around said core and extending throughout the length of the cable and a covering of electrically insulating material, the cable being divided into at least two groups of alternating sectors extending in the longitudinal direction of the cable, which sectors assume mutually different temperatures during use of the cable, said heating wire comprising sections having a comparatively high resistance per unit of length alternated by sections having a comparatively low resistance per unit of length.
Claim 2
Dependent Claim
93 words
An electric redistance heating cable comprising a flexible core of electrically insulating material, a heating wire wound helically around said core and extending throughout the length of the cable and a covering of electrically insulating material, the cable being divided into at least two groups of alternating sectors extending in the longitudinal direction of the cable, which sectors assume mutually different temperatures during use of the cable, said heating wire comprising sections having a comparatively high resistance per unit of length alternated by sections having a comparatively low resistance per unit of length.
Claim 3
Dependent Claim
52 words
The electric resistance heating cable as claimed in claim 1, wherein the heating wire comprises a wire having a comparatively high resistance per unit of length which is provided at regular distances with envelopes having a comparatively low resistance per unit of length and extEnding in the longitudinally direction of the wire.
Claim 4
Dependent Claim
85 words
The electric resistance heating cable as claimed in claim 1, wherein the heating wire comprises a wire having a comparatively high resistance per unit of length which is provided at regular distances with envelopes having a comparatively low resistance per unit of length and extending in the longitudinal direction of the wire, and further comprising an envelope extending throughout the length of the wire comprising a material which is still resistant to oxidation at the highest temperature which is reached during operation of the cable.
References Cited (Backward Citations)
DE290451C
Cited
US3461275A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |