Patent US3105029A successfully refreshed from Google Patents.
Patent US3878495A successfully refreshed from Google Patents.
US3878495A
Expired / Lapsed
US
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Magnetic core for electrical inductive apparatus
Assignee: ABB Inc USA
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Filing: 1974-07-02
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Granted: 1975-04-15
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Expires: 1994-07-02
Abstract
Abstract A multiple-legged magnetic core constructed from groups of laminations, with at least two of the groups having different permeabilities. The majority of the magnetic core is constructed of laminations having one permeability. A group of laminations having a lower permeability is positioned in each of the outer legs or in the yoke portions which connect the outer legs to the remainder of the magnetic core. The effective permeability of the outer legs is thereby reduced and the flux density throughout the core is substantially balanced.
Inventors
- 👤 Michael W Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:34
CPC Classifications
H; H01; H01F; H01F27/00; H01F27/24; H01F27/245; H01F3/00; H01F3/10; H01F2003/106
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
96 words
A magnetic core comprising: at least first and second laminated inner core legs suitable for the placement of windings there-around; first and second laminated outer core legs; and first and second laminated cores yokes which magnetically connect together the inner core legs and the outer core legs; said first and second laminated outer core legs respectively providing first and second magnetic paths with the core yokes, with said first and second paths each containing a first group of laminations having a first predetermined permeability and a second group of laminations having a second and different permeability.
Claim 2
Dependent Claim
96 words
A magnetic core comprising: at least first and second laminated inner core legs suitable for the placement of windings there-around; first and second laminated outer core legs; and first and second laminated cores yokes which magnetically connect together the inner core legs and the outer core legs; said first and second laminated outer core legs respectively providing first and second magnetic paths with the core yokes, with said first and second paths each containing a first group of laminations having a first predetermined permeability and a second group of laminations having a second and different permeability.
Claim 3
Dependent Claim
93 words
The magnetic core of claim 1 wherein the first magnetic path traverses the first outer core leg, the first inner core leg, and the portions of the core yokes connecting said legs, and wherein a third magnetic path traverses the first and second inner core legs and the portions of the core yokes connecting said legs, with the permeability of the laminations in the second group of laminations of the first outer core leg having a value of permeability which makes the effective length of the first and third magnetic paths substantially equal.
Claim 4
Dependent Claim
21 words
The magnetic core of claim 1 wherein the first and second groups of laminations are joined together with a step-lapped joint.
Claim 5
Dependent Claim
52 words
The magnetic core of claim 1 wherein the first group of laminations is constructed of steel laminations having a grain orientation aligned parallel to the edges of the lamination, and the second group of laminations is constructed of steel laminations having a grain orientation aligned obliquely to the edges of the lamination.
Claim 6
Dependent Claim
69 words
A five-legged magnetic core comprising: first, second and third laminated inner core legs; first and second laminated outer core legs; and first and second laminated core yokes which magnetically connect together the inner core legs and the outer core legs; said first and second outer magnetic core legs containing laminations having a lower permeability than the permeability of substantially all the laminations in the remainder of the magnetic core.
Claim 7
Dependent Claim
69 words
A five-legged magnetic core comprising: first, second and third laminated inner core legs; first and second laminated outer core legs; and first and second laminated core yokes which magnetically connect together the inner core legs and the outer core legs; said first and second outer magnetic core legs containing laminations having a lower permeability than the permeability of substantially all the laminations in the remainder of the magnetic core.
Claim 8
Dependent Claim
68 words
A four-legged magnetic core comprising: first and second laminated inner core legs; first and second laminated outer core legs; and first and second laminated core yokes which magnetically connect together the inner core legs and the outer core legs; said first and second outer magnetic core legs containing laminations having a lower permeability than the permeability of substantially all the laminations in the remainder of the magnetic core.
Claim 9
Dependent Claim
68 words
A four-legged magnetic core comprising: first and second laminated inner core legs; first and second laminated outer core legs; and first and second laminated core yokes which magnetically connect together the inner core legs and the outer core legs; said first and second outer magnetic core legs containing laminations having a lower permeability than the permeability of substantially all the laminations in the remainder of the magnetic core.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |