Patent US3916150A successfully refreshed from Google Patents.
US3602631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical apparatus in an underground case
Assignee: Westinghouse Electric Corp
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Filing: 1970-06-04
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Granted: 1971-08-31
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Expires: 1990-06-04
Abstract
Abstract Fluid filled electrical apparatus, such as transformers, suitable for underground or vault mounting. The electrical apparatus includes a laminated tank or casing, having at least three metallic layers, with the layer materials and thicknesses being selected to provide a good structural material having long service life in corrosion conducive environments, without undue economic penalty.
Inventors
- 👤 Harry R Sheppard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:19
CPC Classifications
H; H01; H01F; H01F27/00; H01F27/02; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/923; Y10S428/924; Y10S428/925; Y10S428/926; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12556; Y10T428/12569; Y10T428/12771; Y10T428/12861; Y10T428/12951; Y10T428/12958; Y10T428/12965; Y10T428/12972; Y10T428/12979
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
108 words
Electrical apparatus comprising: a casing, an electrically conductive element disposed in said casing, said electrically conductive element being adapted for connection to an electrical potential; and fluid means disposed in said casing, said casing being at least partially constructed from a laminated metallic structure having at least first, second and third layers, said first layer being a structural layer, in contact with said fluid means, said second layer being a barrier layer, disposed between said first and third layers, to protect said first layer from corrosion, and said third layer being anodic to said second layer, forming a sacrificial anode to reduce pitting corrosion of the second layer.
Claim 2
Dependent Claim
108 words
Electrical apparatus comprising: a casing, an electrically conductive element disposed in said casing, said electrically conductive element being adapted for connection to an electrical potential; and fluid means disposed in said casing, said casing being at least partially constructed from a laminated metallic structure having at least first, second and third layers, said first layer being a structural layer, in contact with said fluid means, said second layer being a barrier layer, disposed between said first and third layers, to protect said first layer from corrosion, and said third layer being anodic to said second layer, forming a sacrificial anode to reduce pitting corrosion of the second layer.
Claim 3
Dependent Claim
30 words
The electrical apparatus of claim 1 wherein at least the first layer is a carbon steel and the second layer is a steel alloy containing at least 12 percent chromium.
Claim 4
Dependent Claim
30 words
The electrical apparatus of claim 1 wherein at least the third layer is a carbon steel and the second layer is a steel alloy containing at least 12 percent chromium.
Claim 5
Dependent Claim
23 words
The electrical apparatus of claim 1 wherein the first and third layers are carbon steels and the second layer is a stainless steel.
Claim 6
Dependent Claim
17 words
The electRical apparatus of claim 1 wherein the first layer is substantially thicker than the second layer.
Claim 7
Dependent Claim
23 words
The electrical apparatus of claim 1 wherein the second layer has a thickness dimension in the range of about 0.001 to 0.020 inch.
Claim 8
Dependent Claim
15 words
The electrical apparatus of claim 1 including an insulating coating disposed on the third layer.
Claim 9
Dependent Claim
34 words
The electrical apparatus of claim 1 wherein the first and third layers are carbon steels and the second layer is a stainless steel, and the first layer is substantially thicker than the second layer.
Claim 10
Dependent Claim
36 words
The electrical apparatus of claim 1 wherein the first and third layers are carbon steels and the second layer is a stainless steel, and the second and third layers are each thinner than the first layer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-30 | 1975-03-01 | 1975-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-30 | 1979-03-01 | 1979-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-30 | 1983-03-01 | 1983-08-31 | $7700.00 | Window Closed / Lapsed |