Patent US4520230A successfully refreshed from Google Patents.
US4520230A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cross-linked polyethylene insulated power cable with improved electric breakdown strength and method for manufacturing the same
Assignee: Furukawa Electric Co Ltd
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Filing: 1983-08-15
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Granted: 1985-05-28
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Expires: 2003-08-15
Abstract
Abstract There are disclosed a cross-linked polyethylene insulated power cable with improved electric breakdown strength having a conductor covered with a cross-linked polyethylene insulating layer having a density of 0.918 g/cm3 or more, a crystal thickness of 76 ANGSTROM or more, and a gel fraction of 60% or more; and a method for manufacturing such a power cable.
Inventors
- 👤 Kenji Uesugi
- 👤 Shin-ichi Irie
- 👤 Yoshihisa Asada
- 👤 Masahiro Maeda
- 👤 Nobuyuki Yamada
- 👤 Hideaki Nakagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:31
CPC Classifications
H; H01; H01B; H01B9/00; H01B9/02; H01B9/027; H01B13/00; H01B13/06; H01B13/14; H01B13/145; H01B3/00; H01B3/18; H01B3/30; H01B3/44; H01B3/441; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/294; Y10T428/2942; Y10T428/2947
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
79 words
A cross-linked polyethylene insulated power cable with improved electric breakdown strength, comprising an elongated conductor and an insulating layer of cross-linked polyethylene surrounding said conductor, said cross-linked polyethylene having a density of 0.918 g/cm 3 or more, a crystal thickness of 76 Å or more and a gel fraction of 60% or more, the ratio of the impulse breakdown strength of said cross-linked polyethylene at 90° C. to the impulse breakdown strength at room temperature being at least 80%.
Claim 2
Dependent Claim
79 words
A cross-linked polyethylene insulated power cable with improved electric breakdown strength, comprising an elongated conductor and an insulating layer of cross-linked polyethylene surrounding said conductor, said cross-linked polyethylene having a density of 0.918 g/cm 3 or more, a crystal thickness of 76 Å or more and a gel fraction of 60% or more, the ratio of the impulse breakdown strength of said cross-linked polyethylene at 90° C. to the impulse breakdown strength at room temperature being at least 80%.
Claim 3
Dependent Claim
38 words
The cross-linked polyethylene insulated power cable with improved electric breakdown strength according to claim 1, wherein the cross-linked polyethylene has a degree of orientation of 100 CPS or more as measured by the wide angle X-ray diffraction method.
Claim 4
Dependent Claim
29 words
The cross-linked polyethylene insulated power cable with improved electric breakdown strength according to claim 1, wherein the cross-linked polyethylene has a crystal thickness of 76 Å to 108 Å.
Claim 5
Dependent Claim
31 words
The cross-linked polyethylene insulated power cable with improved electric breakdown stength according to claim 1, wherein the cross-linked polyethylene has a density of 0.918 g/cm 3 to 0.928 g/cm 3 .
Claim 6
Dependent Claim
27 words
The cross-linked polyethylene insulated power cable with improved electric breakdown strength according to claim 1, wherein the cross-linked polyethylene has a gel fraction of 60% to 84%.
Claim 7
Dependent Claim
67 words
The cross-linked polyethylene insulated power cable with improved electric breakdown strength according to claim 3, wherein the cross-linked polyethylene has a density of 0.918 g/cm 3 to 0.928 g/cm 3 ; wherein the cross-linked polyethylene has a gel fraction of 60% to 84%; and wherein said cross-linked polyethylene has a degree of orientation of 100 CPS or more as measured by the wide angle X-ray diffraction method.
Claim 8
Dependent Claim
88 words
The cross-linked polyethylene insulated power cable with improved electric breakdown strength according to claim 1 further comprising: an internal semiconducting layer formed between said elongated conductor and said insulating layer; and outer layers sequentially formed on the outside of said insulating layer, said outer layers comprising an outer semiconducting layer in direct contact with the outside of said insulating layer, a metal shielding layer formed on the outer surface of said outer semiconducting layer, and a sheath layer formed on the outer surface of said metal shielding layer.
References Cited (Backward Citations)
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GB1108762A
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US3441660A
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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) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |