US3780206A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric cables
Assignee: Balfour Beatty PLC
•
Filing: 1971-11-26
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Granted: 1973-12-18
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Expires: 1991-11-26
Abstract
Abstract A conductive or semiconductive fibrous sheet material used as an electric screen in contact with the dielectric fluid of high voltage cables having a fluid impregnated dielectric is loaded both with conductive carbon and with at least one active, finely divided material selected from the group consisting of aluminium oxide and such other metallic oxides, hydrated metal oxides, metal hydroxides, metal carbonates and basic metal carbonates as have adsorptive powers comparable with that of active finely divided aluminum oxide. The dielectric is free of any adsorbent.
Inventors
- 👤 E Reynolds
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:28
CPC Classifications
H; H01; H01B; H01B9/00; H01B9/06; H01B9/0611; H01B9/02; H01B9/027
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
177 words
An electric cable, comprising a. at least one metallic conductor, b. a fluid impregnated dielectric surrounding said conductor and bounded at each of its inner and outer circumferential surfaces by an electric screen in contact with said fluid and formed from a fibrous material in the form of a flexible sheet loaded with conductive carbon black and c. an external fluid-tight sheath, the said cable being characterized in that the said electric screens each comprise a first layer of a multi-ply fibrous sheet material comprising one ply contiguous with the dielectric and loaded with an active finely divided adsorbent material selected from the group consisting of aluminum oxide and such other active metallic oxides, hydrated metal oxides, metal hydroxides, metal carbonates and basic metal carbonates as have adsorptive powers comparable with that of active finely divided aluminum oxide and another ply loaded with conductive carbon black and a second layer of material loaded with conductive carbon black and contiguous with said other play and further characterized in that the said dielectric is free of any adsorbent material.
Claim 2
Dependent Claim
55 words
A cable as claimed in claim 2 in which said second layer is also loaded with an active finely divided material selected from the group consisting of aluminium oxide and such other metallic oxides, metal hydroxides, metal carbonates and basic metal carbonates as have adsorptive powers comparable with that of active finely divided aluminium oxide.
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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) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |