US4904972A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas-insulated stationary induction electrical apparatus
Assignee: Hitachi Ltd
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Filing: 1989-06-28
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Granted: 1990-02-27
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Expires: 2009-06-28
Abstract
Abstract A gas-insulated stationary induction electrical apparatus comprising a first closed vessel sealingly accommodating therein a main body having an iron core formed by laminating silicon steel sheets and also having at least one set of windings each consisting of a high-voltage winding and a low-voltage winding which are disposed apart from the iron core on both sides thereof, and a liquid medium for effecting cooling and insulation; a second closed vessel formed of an insulating material and sealingly accommodating therein the first closed vessel; and an insulating gas under a predetermined pressure which is sealed within the gap between the first and second vessels, wherein the induction apparatus main body is submerged in the liquid medium.
Inventors
- 👤 Etsunori Mori
- 👤 Tadashi Kiuchi
- 👤 Kiyoto Hiraishi
- 👤 Masaru Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:38
CPC Classifications
H; H01; H01F; H01F27/00; H01F27/08; H01F27/02; H01F27/10; H01F27/12; H01F27/125
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
114 words
A gas-insulated stationary induction electrical apparatus comprising: a first closed vessel sealing accommodating therein a main body having an iron core formed by laminating silicon steel sheets and also having at least one set of windings each consisting of a high-voltage winding and a low-voltage winding which are disposed apart from said iron core on both side thereof, and a liquid medium for effecting cooling and insulation; a second closed vessel formed of an insulating material and sealingly accommodating therein said first closed vessel; and an insulating gas under a predetermined pressure which is sealed within the gap between said first and second vessels, wherein said main body is submerged in said liquid medium.
Claim 2
Dependent Claim
114 words
A gas-insulated stationary induction electrical apparatus comprising: a first closed vessel sealing accommodating therein a main body having an iron core formed by laminating silicon steel sheets and also having at least one set of windings each consisting of a high-voltage winding and a low-voltage winding which are disposed apart from said iron core on both side thereof, and a liquid medium for effecting cooling and insulation; a second closed vessel formed of an insulating material and sealingly accommodating therein said first closed vessel; and an insulating gas under a predetermined pressure which is sealed within the gap between said first and second vessels, wherein said main body is submerged in said liquid medium.
Claim 3
Dependent Claim
33 words
An induction electrical apparatus according to claim 1, wherein said first closed vessel has a circulating pump and a cooling device whereby said medium within said first closed vessel is cooled and circulated.
Claim 4
Dependent Claim
20 words
An induction electrical apparatus according to claim 1, wherein said first closed vessel is formed integrally of an insulating material.
Claim 5
Dependent Claim
21 words
An induction electrical apparatus according to claim 1, wherein said first closed vessel is formed by a plurality of insulating members.
Claim 6
Dependent Claim
24 words
An induction electrical apparatus according to claim 1, wherein an upper portion of said first closed vessel is formed by a vertically movable diaphragm.
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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) | 1993-02-26 | 1993-08-28 | 1994-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-26 | 1997-08-28 | 1998-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-26 | 2001-08-28 | 2002-02-27 | $7700.00 | Window Closed / Lapsed |