Patent US3594489A successfully refreshed from Google Patents.
US3594489A
Expired / Lapsed
US
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Extra high voltage cables
Assignee: General Cable Corp
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Filing: 1968-10-07
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Granted: 1971-07-20
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Expires: 1988-10-07
Abstract
Abstract For extra high voltage power cables this invention provides insulation consisting of synthetic plastic material with paper bonded to both sides to form a laminated strip. In place of the porous paper previously used, this invention uses very thin paper such as ''''capacitor tissue''''; space for the thermal expansion of the synthetic and passages for the removal of moisture and the introduction of oil are obtained by embossing the strip. To prevent locking of overlying strips when bending the cable, the embossing is preferably embossed with a random pattern, or plain unembossed strips are wrapped alternately between embossed strips. The invention includes the novel strip, cable made with the strip and the method of making the strip.
Inventors
- 👤 Carlos Katz
- 👤 George S Eager Jr
- 👤 George Bahder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:50
CPC Classifications
H; H01; H01B; H01B13/00; H01B13/06; H01B3/00; H01B3/002
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
116 words
An extra high voltage electrical cable including a conductor, shielding and insulation around the conductor, the insulation including impervious layers of laminated dielectric material comprising a synthetic plastic film of good dielectric properties and mechanically reinforced by a paper sheet bonded to the surface of the plastic but thinner than the plastic film said paper being highly impermeable to liquid dielectric in a radial direction, at least some of the laminated insulation being embossed to form expansion and communicating spaces between overlapping layers of the composite insulation, said spaces being filled with fluid dielectric, the paper having a thickness from 0.0002 inch to 0.0015 inch and a density in the range from 0.2 to 1.2 g./cc.
Claim 2
Dependent Claim
116 words
An extra high voltage electrical cable including a conductor, shielding and insulation around the conductor, the insulation including impervious layers of laminated dielectric material comprising a synthetic plastic film of good dielectric properties and mechanically reinforced by a paper sheet bonded to the surface of the plastic but thinner than the plastic film said paper being highly impermeable to liquid dielectric in a radial direction, at least some of the laminated insulation being embossed to form expansion and communicating spaces between overlapping layers of the composite insulation, said spaces being filled with fluid dielectric, the paper having a thickness from 0.0002 inch to 0.0015 inch and a density in the range from 0.2 to 1.2 g./cc.
Claim 3
Dependent Claim
19 words
The electrical cable described in claim 1 characterized by the composite dielectric being irradiated to improve its thermal stability.
Claim 4
Dependent Claim
72 words
The electrical cable described in claim 1 characterized by the composite dielectric layers having capacitor tissue bonded to the plastic whereby the laminate including the paper is highly impermeable to liquid dielectric, the embossing being of a depth correlated with known impregnation and thermal expansion of the plastic and fluid to provide space for the expansion and to provide communicating spaces between overlapping layers of the composite insulation and their butt spaces.
Claim 5
Dependent Claim
77 words
The electrical cable described in claim 3 characterized by the embossing of the dielectric strips being in a random pattern that does not lock up with the embossing of an underlying or overlying layer when the cable is bent, and the separate layers having helically wound laminate with butt spaces between successive convolutions bridged by the paper of underlying and overlying layers to prevent the plastic from flowing into the butt spaces when the cable is heated.
Claim 6
Dependent Claim
53 words
The electric cable described in claim 3 characterized by each layer of embossed dielectric strip having a uniform pattern of embossing and being in alternating relation with a layer of plain unembossed dielectric strip to prevent locking of embossed surfaces of strips with confronting surfaces of other strips when the cable is bent.
Claim 7
Dependent Claim
35 words
The electrical cable described in claim 1 characterized by the plastic film being about 2 to 10 mils in thickness and the paper being sheets of capacitor tissue bonded to both surfaces of the plastic.
Claim 8
Dependent Claim
56 words
The electrical cable described in claim 1 characterized by some of the layers of dielectric material being of greater radial thickness than others, and the layers of greater thickness have their paper sheets embossed to a greater depth to provide more space for the expansion of the plastic film, and for moisture removal and liquid impregnation.
Claim 9
Dependent Claim
51 words
The electrical cable described in claim 7 characterized by layers of dielectric material toward the outside of the cable having plastic of greater radial thickness than layers nearer the center of the cable, the depth of embossing being in accordance with the thickness of the plastic film of the respective layers.
Claim 10
Dependent Claim
15 words
The electrical cable described in claim 7 characterized by tHe layers of dielectric being irradiated.
Claim 11
Dependent Claim
50 words
The electrical cable described in claim 1 characterized by insulation including tapes comprising plastic film bonded between sheets of paper and including other tapes of conventional high purity, low-loss paper insulation, the conventional paper tapes being limited to not more than about 15 percent of the total insulation cross section.
Claim 12
Dependent Claim
27 words
The electrical cable described in claim 1 characterized by the insulation having inner and outermost layers of tape, at least one of which is a paper tape.
References Cited (Backward Citations)
US3078333A
Cited
CA690353A
Cited
GB925403A
Cited
US3105872A
Cited
US3250850A
Cited
US3194872A
Cited
US3429983A
Cited
US3358071A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |