US3930112A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mixed fluid impregnant for oil filled electric cables
Assignee: Pirelli and C SpA
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Filing: 1975-03-17
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Granted: 1975-12-30
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Expires: 1995-03-17
Abstract
Abstract An underwater electric power cable in which the normal liquid impregnant, such as alkylaryl derivatives, polybutenes, polyisobutylenes, mineral oils, etc. having a specific gravity less than the specific gravity of water, is mixed with a second liquid having a specific gravity higher than that of water in proportions which will provide a mixture having a specific gravity substantially equal to that of the water in which the cable is immersed. The second liquid is miscible with the first liquid, and has low dielectric losses, a low dielectric constant, a viscosity at least as low as that of the first liquid and a boiling point of at least 150*C. A halogenated hydrocarbon, such as hexachlorobutadiene, is a preferred second liquid.
Inventors
- 👤 Franco Pasini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:34
CPC Classifications
H; H01; H01B; H01B7/00; H01B7/14; H01B13/00; H01B13/30; H01B9/00; H01B9/06; H01B9/0611
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
155 words
A liquid-filled underwater, electric power cable comprising a conductor surrounded by insulation, said insulation being impregnated with a mixture of a first liquid having a predetermined viscosity, a predetermined boiling point, a specific gravity less than that of water, low dielectric losses and a low dielectric constant with a second liquid miscible with said first liquid, a viscosity at least as low as that of said first liquid, a boiling point at least as high as 150*C, a specific gravity higher than that of water and dielectric losses and a dielectric constant respectively substantially at least as low as said dielectric losses and said dielectric constant of said first liquid, said first liquid being at least 50 percent by weight of the mixture and the weight of the second liquid being at least equal to the amount thereof required to provide a specific gravity of the mixture substantially equal to the specific gravity of water.
Claim 2
Dependent Claim
155 words
A liquid-filled underwater, electric power cable comprising a conductor surrounded by insulation, said insulation being impregnated with a mixture of a first liquid having a predetermined viscosity, a predetermined boiling point, a specific gravity less than that of water, low dielectric losses and a low dielectric constant with a second liquid miscible with said first liquid, a viscosity at least as low as that of said first liquid, a boiling point at least as high as 150*C, a specific gravity higher than that of water and dielectric losses and a dielectric constant respectively substantially at least as low as said dielectric losses and said dielectric constant of said first liquid, said first liquid being at least 50 percent by weight of the mixture and the weight of the second liquid being at least equal to the amount thereof required to provide a specific gravity of the mixture substantially equal to the specific gravity of water.
Claim 3
Dependent Claim
34 words
A cable as set forth in claim 1 wherein said first liquid is selected from the group consisting of alkyl-aryl derivatives, polybutenes, polyisobutylenes, and mineral oils and said second liquid is a halogenated hydrocarbon.
Claim 4
Dependent Claim
15 words
A cable as set forth in claim 2 wherein said first liquid is an alkylbenzene.
Claim 5
Dependent Claim
16 words
A cable as set forth in claim 3 wherein said second liquid is a chlorinated hydrocarbon.
Claim 6
Dependent Claim
14 words
A cable as set forth in claim 4 wherein said chlorinated hydrocarbon is hexachlorobutadiene.
Claim 7
Dependent Claim
30 words
A cable as set forth in claim 5 wherein said first liquid is decylbenzene and the weight percentage of hexachlorobutadiene is from 20 up to 50 percent of said mixture.
Claim 8
Dependent Claim
37 words
A cable as set forth in claim 1 wherein the specific gravity of said first liquid is between 0.84 and 0.90 g/cm3 and the viscosity of said first liquid is between 2 and 30 centiStokes at 20*C.
Claim 9
Dependent Claim
122 words
An electric power cable fluid impregnant comprising at least 50 percent by weight of a first liquid having a predetermined viscosity, a predetermined boiling point, a specific gravity less than that of water, low dielectric losses and a low dielectric constant mixed with a second liquid miscible with said first liquid, a boiling point at least as high as 150*C, a specific gravity higher than that of water, and dielectric losses and a dielectric constant respectively substantially at least as low as said dielectric losses and said dielectric constant of said first liquid, the weight percent of said second liquid being at least sufficient to provide a specific gravity for the mixture which is substantially equal to the specific gravity of water.
Claim 10
Dependent Claim
122 words
An electric power cable fluid impregnant comprising at least 50 percent by weight of a first liquid having a predetermined viscosity, a predetermined boiling point, a specific gravity less than that of water, low dielectric losses and a low dielectric constant mixed with a second liquid miscible with said first liquid, a boiling point at least as high as 150*C, a specific gravity higher than that of water, and dielectric losses and a dielectric constant respectively substantially at least as low as said dielectric losses and said dielectric constant of said first liquid, the weight percent of said second liquid being at least sufficient to provide a specific gravity for the mixture which is substantially equal to the specific gravity of water.
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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) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |