Patent US4012706A successfully refreshed from Google Patents.
US4012706A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheet-wound transformer coils
Assignee: General Electric Co
•
Filing: 1975-12-08
•
Granted: 1977-03-15
•
Expires: 1995-12-08
Abstract
Abstract In sheet-wound transformer coils, excessive ohmic losses due to high current density at the sheet edges caused by a radial magnetic leakage field are avoided by adding apparatus adjacent the edges which may comprise individual strips that are transposed as the coil is wound. In one alternative embodiment, the apparatus adjacent the edges comprises separate parallel strips of high magnetic permeability material assembled in conjunction with the coils. In another alternative embodiment, wire-wound coils are employed at each edge of the sheet-wound coils.
Inventors
- 👤 Willem F. Westendorp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:43
CPC Classifications
H; H01; H01F; H01F27/00; H01F27/34; H01F27/346; H01F27/36; H01F27/366; H01F27/38
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
102 words
An electrical transformer comprising: at least one conductive sheet overlaid by insulation; a closed loop magnetic core, said conductive sheet being wound continuously in a plurality of turns about said core; and a plurality of axially-oriented planar strips of low magnetic reluctance electrically insulated from each other and directed from said closed loop magnetic core substantially perpendicular to the plane of said closed loop magnetic core, said strips being situated closely adjacent at least one substantially entire axial edge of said turns and carrying a large radial component of the magnetic flux leakage field established by current flow through said conductive sheet.
Claim 2
Dependent Claim
102 words
An electrical transformer comprising: at least one conductive sheet overlaid by insulation; a closed loop magnetic core, said conductive sheet being wound continuously in a plurality of turns about said core; and a plurality of axially-oriented planar strips of low magnetic reluctance electrically insulated from each other and directed from said closed loop magnetic core substantially perpendicular to the plane of said closed loop magnetic core, said strips being situated closely adjacent at least one substantially entire axial edge of said turns and carrying a large radial component of the magnetic flux leakage field established by current flow through said conductive sheet.
Claim 3
Dependent Claim
124 words
An electrical transformer comprising: a closed loop core of magnetic material; a first coil wound about said core, said first coil being formed from a first conductive sheet overlaid by insulation; a second coil wound about said first coil, said second coil including a second conductive sheet overlaid by insulation; and a plurality of axially-oriented planar strips of low magnetic reluctance electrically insulated from each other and directed from said closed loop core substantially perpendicular to the plane of said closed loop core, said strips being situated closely adjacent at least one substantially entire axial edge of each of said first and second coils for carrying a large radial component of the magnetic flux leakage field established by current flow through said conductive sheet.
Claim 4
Dependent Claim
124 words
An electrical transformer comprising: a closed loop core of magnetic material; a first coil wound about said core, said first coil being formed from a first conductive sheet overlaid by insulation; a second coil wound about said first coil, said second coil including a second conductive sheet overlaid by insulation; and a plurality of axially-oriented planar strips of low magnetic reluctance electrically insulated from each other and directed from said closed loop core substantially perpendicular to the plane of said closed loop core, said strips being situated closely adjacent at least one substantially entire axial edge of each of said first and second coils for carrying a large radial component of the magnetic flux leakage field established by current flow through said conductive sheet.
References Cited (Backward Citations)
US1335837A
Cited
FR913281A
Cited
US2850707A
Cited
US2962679A
Cited
US2907965A
Cited
GB827506A
Cited
US3014189A
Cited
GB1030842A
Cited
US3366907A
Cited
FR1557420A
Cited
US3663910A
Cited
US3609613A
Cited
US3750070A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-14 | 1980-09-13 | 1981-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-14 | 1984-09-13 | 1985-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-14 | 1988-09-13 | 1989-03-15 | $7700.00 | Window Closed / Lapsed |