US3582533A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Underground transmission system employing bare conductors supported by electrical insulating foam
Assignee: ABB Inc USA
•
Filing: 1969-09-16
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Granted: 1971-06-01
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Expires: 1989-09-16
Abstract
Abstract High-voltage electric power is transmitted over long distances through bare conductors located underground and surrounded by a foam having insulating gas such as sulphurhexafluoride (SF6) entrapped in the cells thereof. During installation the conductors are supported by means of insulating strings hanging from crossmembers laid across the top surface of an installation ditch until the foam structure solidifies, at which time the insulating strings are cut and the earth backfilled. The solidified foam provides the means of support for the conductors, with the entrapped gases providing the necessary insulation.
Inventors
- 👤 Roy H Albright
- 👤 Robert M Clark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:40
CPC Classifications
H; H02; H02G; H02G9/00; H02G9/06; H02G9/065; H02G9/02; H02G9/025
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
66 words
A system for transmitting high-voltage electric currents from a point of generation to a point of utilization, comprising: a bare conductor carrying said high-voltage electric current; and an underground installation through which said bare conductor runs to carry said current, said conductor being supported in said installation by a closed-cell foam surrounding said conductor and having electrical insulating gas entrapped therein of a high dielectric characteristic.
Claim 2
Independent Claim
66 words
A system for transmitting high-voltage electric currents from a point of generation to a point of utilization, comprising: a bare conductor carrying said high-voltage electric current; and an underground installation through which said bare conductor runs to carry said current, said conductor being supported in said installation by a closed-cell foam surrounding said conductor and having electrical insulating gas entrapped therein of a high dielectric characteristic.
Claim 3
Dependent Claim
51 words
The system of claim 1, in which said underground installation also includes a conductive layer atop said foam for protecting said foam when said installation is backfilled and for reducing the voltage gradient otherwise produced at the top surface of said installation by the high-voltage electric currents passing through said conductor.
Claim 4
Dependent Claim
32 words
The system of claim 2, in which there is also provided a penetration-resistant material along the sides and bottom of the underground installation to prevent destruction of said foam by external elements.
Claim 5
Dependent Claim
14 words
The system of claim 3, in which said insulating entrapped gas iS sulfur hexafluoride.
Claim 6
Dependent Claim
14 words
The system of claim 3, in which said foam is of an epoxy structure.
Claim 7
Independent Claim
93 words
A method of providing an underground transmission system for the carrying of high-voltage electric currents through a ditch or similar such enclosure from a point of generation to a point of utilization comprising the steps of: a. suspending a current-carrying bare conductor within said ditch by an insulating member; b. surrounding said conductor with a closed-cell foam having electrically insulating entrapped gas therein which exhibits a high dielectric characteristic; c. permitting said foam to solidify to support said conductor; and d. covering said solidified foam with a backfill material to close said ditch.
Claim 8
Independent Claim
93 words
A method of providing an underground transmission system for the carrying of high-voltage electric currents through a ditch or similar such enclosure from a point of generation to a point of utilization comprising the steps of: a. suspending a current-carrying bare conductor within said ditch by an insulating member; b. surrounding said conductor with a closed-cell foam having electrically insulating entrapped gas therein which exhibits a high dielectric characteristic; c. permitting said foam to solidify to support said conductor; and d. covering said solidified foam with a backfill material to close said ditch.
Claim 9
Dependent Claim
65 words
The method of claim 6, in which following step c. and preceding step d. there is included the additional step of putting down a conductive layer over said solidified foam to protect said foam when said ditch is backfilled and to reduce the voltage gradient otherwise produced at the top surface of said closed ditch by the high-voltage electric currents passing through said bare conductor.
Claim 10
Dependent Claim
36 words
The method of claim 7, in which prior to step b. there is included the additional step of lining the bottom and at least a portion of the sides of said ditch with a penetration-resistant material.
Claim 11
Dependent Claim
22 words
The method of claim 7, in which step b. comprises surrounding said conductor with a closed-cell foam having sulphurhexafluoride gas entrapped therein.
Claim 12
Dependent Claim
21 words
The method of claim 7, in which step b. comprises surrounding said conductor with a closed-cell foam of an epoxy structure.
References Cited (Backward Citations)
US2355966A
Cited
US3112183A
Cited
FR1318191A
Cited
US3484509A
Cited
US3380285A
Cited
GB1133455A
Cited
US3503800A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |