Patent US4296274A successfully refreshed from Google Patents.
US4296274A
Expired / Lapsed
US
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High voltage bushing having weathershed and surrounding stress relief collar
Assignee: United States Department of Energy
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Filing: 1980-07-11
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Granted: 1981-10-20
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Expires: 2000-07-11
Abstract
Abstract A high voltage electric bushing comprises a hollow elongated dielectric weathershed which encloses a high voltage conductor. A collar formed of high voltage dielectric material is positioned over the weathershed and is bonded thereto by an interface material which precludes moisture-like contaminants from entering between the bonded portions. The collar is substantially thicker than the adjacent weathershed which it surrounds, providing relief of the electric stresses which would otherwise appear on the outer surface of the weathershed. The collar may include a conductive ring or capacitive foil to further relieve electric stresses experienced by the bushing.
Inventors
- 👤 Alan H. Cookson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:53
CPC Classifications
H; H01; H01B; H01B17/00; H01B17/26; H01B17/28
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
142 words
A high voltage bushing comprising: a hollow weathershed having an outside surface and a first end; a high voltage conductor disposed within said weathershed exerting a region of high electric field stress concentration on the outside surface of said weathershed; means contacting the electric field for outwardly directing the concentration of high electric field stress to a predetermined portion of the outside surface of said weathershed; and a dielectric collar surrounding said predetermined portion of said weathershed, said collar having adjacent the region of high electric field stress concentration, a thickness substantially greater than the thickness of said weathershed, said collar further having an outside surface which forms a portion of the outside surface of said bushing; and means, separate from said collar, for supporting said weathershed, whereby the electric field stress concentration on the outside surface of said bushing is relieved.
Claim 2
Dependent Claim
142 words
A high voltage bushing comprising: a hollow weathershed having an outside surface and a first end; a high voltage conductor disposed within said weathershed exerting a region of high electric field stress concentration on the outside surface of said weathershed; means contacting the electric field for outwardly directing the concentration of high electric field stress to a predetermined portion of the outside surface of said weathershed; and a dielectric collar surrounding said predetermined portion of said weathershed, said collar having adjacent the region of high electric field stress concentration, a thickness substantially greater than the thickness of said weathershed, said collar further having an outside surface which forms a portion of the outside surface of said bushing; and means, separate from said collar, for supporting said weathershed, whereby the electric field stress concentration on the outside surface of said bushing is relieved.
Claim 3
Dependent Claim
27 words
The apparatus of claim 1 further comprising electric field stress relief means disposed in said collar for grading the electric field in which said collar is disposed.
Claim 4
Dependent Claim
17 words
The apparatus of claim 2, wherein said electric field stress relief means comprises an electrically conductive ring.
Claim 5
Dependent Claim
26 words
The apparatus of claim 2, wherein said electric field stress relief means comprises at least one electrically conductive shield capacitively coupled to said high voltage conductor.
Claim 6
Dependent Claim
33 words
The apparatus of claim 1, wherein said means for outwardly directing the concentration of high electric field stress comprises an electrically conductive shield disposed within said weathershed to surround said high voltage conductor.
Claim 7
Dependent Claim
40 words
The apparatus of claim 1 wherein said weathershed has a predetermined thickness adjacent the region of high electric field stress concentration, and said collar has a thickness between two and five times greater than said predetermined thickness of said weathershed.
Claim 8
Dependent Claim
21 words
The apparatus of claim 1 wherein said weathershed comprises a truncated cone, with said collar adjacent the base of said cone.
Claim 9
Dependent Claim
28 words
The apparatus of claim 1 further including means for sealing the joinder of said weathershed and said collar from contamination travelling along the outside surface of said weathershed.
Claim 10
Dependent Claim
28 words
The apparatus of claim 8, wherein said sealing means comprises a skirt integrally formed with said weathershed, said skirt overlying the joinder of said weathershed and said collar.
Claim 11
Dependent Claim
36 words
The apparatus of claim 8, further including an interface material between said weathershed and said collar, said interface material bonding said weathershed to said collar while preventing contamination from entering between said weathershed and said collar.
Claim 12
Dependent Claim
14 words
The apparatus of claim 10, wherein said interface material comprises room temperature vulcanizing rubber.
Claim 13
Dependent Claim
13 words
The apparatus of claim 1, wherein said collar is formed of cast epoxy.
References Cited (Backward Citations)
US3544707A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-19 | 1985-04-20 | 1985-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-19 | 1989-04-20 | 1989-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-19 | 1993-04-20 | 1993-10-20 | $7700.00 | Window Closed / Lapsed |