Patent US3948690A successfully refreshed from Google Patents.
US3948690A
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Molded magnetic cores utilizing cut steel particles
Assignee: ABB Inc USA
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Filing: 1974-10-24
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Granted: 1976-04-06
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Expires: 1994-10-24
Abstract
Abstract There is disclosed a magnetic core and the method of making the same. The core is formed of a plurality of microlaminations. Since each discrete microlamination is of elongated rectangular shape, soft, ductile and magnetically insulated, the cores exhibit improved permeability, lower core loss, lower exciting volt amps and exhibit improved high frequency characteristics.
Inventors
- 👤 Norman M. Pavlik
- 👤 James W. Cunningham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:21
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/02; H01F41/0206; H01F41/0246; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/20; H01F1/22; H01F1/24; H02; H02K; H02K1/00; H02K1/02; H02K1/06; H02K15/00; H02K15/02; Y; Y10; Y10S; Y10S264/00; Y10S264/58; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49009
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
104 words
The method of producing magnetic core components for use in electrical apparatus, the steps comprising severing microlaminations from thin, flat strips of ferrous alloys, said microlaminations being substantially of elongated rectangular shape, annealing said microlaminations in decarburizing and deoxidixing atmospheres to improve the magnetic characteristics by reducing carbon to less than 0.01% reducing the oxygen to low values and relieving stresses, applying a thin elastic electrical insulation to the microlaminations, assembling a plurality of the microlaminations within a mold of predetermined configuration, aligning the microlaminates into a desired orientation, and thereafter pressing the aligned microlaminations into the solidified configuration of the desired core component.
Claim 2
Independent Claim
104 words
The method of producing magnetic core components for use in electrical apparatus, the steps comprising severing microlaminations from thin, flat strips of ferrous alloys, said microlaminations being substantially of elongated rectangular shape, annealing said microlaminations in decarburizing and deoxidixing atmospheres to improve the magnetic characteristics by reducing carbon to less than 0.01% reducing the oxygen to low values and relieving stresses, applying a thin elastic electrical insulation to the microlaminations, assembling a plurality of the microlaminations within a mold of predetermined configuration, aligning the microlaminates into a desired orientation, and thereafter pressing the aligned microlaminations into the solidified configuration of the desired core component.
Claim 3
Dependent Claim
29 words
The method of claim 1 in which the material from which the microlaminations are formed is an iron alloy having a carbon content between about 0.05% and about 0.15%.
Claim 4
Dependent Claim
42 words
The method of claim 1 in which the microlaminations each have dimensions within the range between about 0.05 and about 0.10 inch in length, about 0.005 to about 0.05 inch in width and from about 0.002 to about 0.02 inch in thickness.
Claim 5
Dependent Claim
22 words
The method of claim 1 in which the microlaminations are annealed at a temperature between about 700° C and about 800° C.
Claim 6
Dependent Claim
26 words
The method of claim 4 in which the microlaminations during annealing are heated to said temperature for a time period of up to about 6 hours.
Claim 7
Dependent Claim
19 words
The method of claim 4 in which the microlaminations are decarburized during the initial portion of the annealing cycle.
Claim 8
Dependent Claim
23 words
The method of claim 4 in which the annealing atmosphere during decarburization consists of hydrogen having a dewpoint in excess of +120° F.
Claim 9
Dependent Claim
25 words
The method of claim 7 in which the decarburization treatment is followed by a treatment in hydrogen having a dewpoint of less than -40° F.
Claim 10
Dependent Claim
22 words
The method of claim 7 in which the decarburization annealing takes place for a period between about 0.5 and about 2 hours.
Claim 11
Dependent Claim
33 words
The method of claim 1 in which the annealed microlaminates are coated in a slurry containing at least about 6% by volume of a magnesium formulation for forming a magnetically insulative coating thereon.
Claim 12
Dependent Claim
17 words
The method of claim 1 in which the microlaminations are insulated with a coating of magnesium methylate.
Claim 13
Dependent Claim
23 words
The method of claim 1 in which the microlaminations are magnetically aligned in a die and thereafter immediately pressed into the desired configuration.
Claim 14
Dependent Claim
20 words
The method of claim 1 in which the microlaminations are magnetically aligned and thereafter hydrostatically pressed into the desired configuration.
Claim 15
Dependent Claim
21 words
The method of claim 1 in which a binder is admixed with the microlaminations prior to pressing and set during pressing.
Claim 16
Dependent Claim
18 words
The method of claim 1 in which a binder is admixed with the microlaminations and set after pressing.
Claim 17
Dependent Claim
41 words
The method of claim 1 in which a magnetic coil with a pole piece is disposed within the mold containing loose microlaminations and said magnetic coil is energized prior to compressing said microlaminations for aligning the same into a predetermined configuration.
Claim 18
Dependent Claim
76 words
In the method of making a molded magnetic core, the steps comprising, forming a plurality of substantially elongated flat, rectangular-shaped microlaminations from a plain carbon steel containing from about 0.05% to about 0.15% carbon, annealing the microlaminations to improve the magnetic characteristics thereof, magnetically insulating said microlaminations, assembling said microlaminations into a preformed configuration while aligning the same into a desired orientation and thereafter pressing said microlaminations into high space factor core having the mold configuration.
Claim 19
Dependent Claim
76 words
In the method of making a molded magnetic core, the steps comprising, forming a plurality of substantially elongated flat, rectangular-shaped microlaminations from a plain carbon steel containing from about 0.05% to about 0.15% carbon, annealing the microlaminations to improve the magnetic characteristics thereof, magnetically insulating said microlaminations, assembling said microlaminations into a preformed configuration while aligning the same into a desired orientation and thereafter pressing said microlaminations into high space factor core having the mold configuration.
Claim 20
Dependent Claim
24 words
The method of claim 17 in which a magnetic field is employed to align the microlaminations into said configuration and with a desired orientation.
Claim 21
Dependent Claim
27 words
The method of claim 18 in which the microlaminations are subjected to sufficient pressure during pressing to provide at least an 85% packing factor in the core.
Claim 22
Dependent Claim
22 words
The method of claim 19 in which the assembled aligned microlaminations are subjected to a static pressure of at least 50,000 psi.
Claim 23
Dependent Claim
58 words
A molded magnetic core comprising, a plurality of ferrous base metal microlaminations formed of substantially flat, elongated, rectangular platelets, each of said platelets having been stress-relieved, decarburized, deoxidized and insulated from one another, the microlaminations being aligned in a predetermined orientation and pressed into the desired configuration, the pressed core exhibiting a packing factor in excess of 85%.
Claim 24
Dependent Claim
58 words
A molded magnetic core comprising, a plurality of ferrous base metal microlaminations formed of substantially flat, elongated, rectangular platelets, each of said platelets having been stress-relieved, decarburized, deoxidized and insulated from one another, the microlaminations being aligned in a predetermined orientation and pressed into the desired configuration, the pressed core exhibiting a packing factor in excess of 85%.
Claim 25
Dependent Claim
47 words
The core of claim 21 in which the microlaminations are essentially parallelopiped in shape and have dimensions within the range between about 0..05 and about 0.10 inch in length, about 0.005 and about 0.05 inch in width and from about 0.002 and about 0.02 inch in thickness.
Claim 26
Dependent Claim
19 words
The core of claim 21 in which the microlaminations are molded into the preferred configuration and include a binder.
Claim 27
Dependent Claim
22 words
The core of claim 21 in which the platelets after decarburizing have a carbon content of less than about 0.01% by weight.
Claim 28
Dependent Claim
72 words
A microlamination suitable for use in molded magnetic components comprising, a substantially flat, elongated rectangular steel particle having dimensions including from about 0.05 and about 0.10 inch in length, about 0.005 and about 0.05 inch in width and from about 0.002 and about 0.02 inch in thickness, a carbon content of less than about 0.002% by weight, are substantially stress-free and having a magnetically insulating coating covering the surface of the microlaminations.
Claim 29
Dependent Claim
72 words
A microlamination suitable for use in molded magnetic components comprising, a substantially flat, elongated rectangular steel particle having dimensions including from about 0.05 and about 0.10 inch in length, about 0.005 and about 0.05 inch in width and from about 0.002 and about 0.02 inch in thickness, a carbon content of less than about 0.002% by weight, are substantially stress-free and having a magnetically insulating coating covering the surface of the microlaminations.
Claim 30
Dependent Claim
31 words
The microlamination of claim 25 in which the carbon content of the steel from which the microlamination is formed is within the range between about 0.07% and about 0.13% by weight.
Claim 31
Dependent Claim
81 words
In the method of making a molded magnetic core, the steps comprising, forming a plurality of substantially elongated, flat, rectangular-shaped microlaminations from magnetic alloys, heat treating the microlaminations to improve the magnetic characteristics compared to those characteristics exhibited by the alloy in the "as-severed" condition, magnetically insulating the microlaminations, assembling the insulated microlaminations into the desired configuration of the core and thereafter subjecting the microlaminations to sufficient pressure to form a molded core exhibiting a packing factor in excess of 85%.
Claim 32
Dependent Claim
81 words
In the method of making a molded magnetic core, the steps comprising, forming a plurality of substantially elongated, flat, rectangular-shaped microlaminations from magnetic alloys, heat treating the microlaminations to improve the magnetic characteristics compared to those characteristics exhibited by the alloy in the "as-severed" condition, magnetically insulating the microlaminations, assembling the insulated microlaminations into the desired configuration of the core and thereafter subjecting the microlaminations to sufficient pressure to form a molded core exhibiting a packing factor in excess of 85%.
Claim 33
Dependent Claim
57 words
A molded magnetic core comprising a plurality of magnetic alloy microlaminations, each of said microlaminations having been heat treated to improve the magnetic characteristics thereof, and magnetically insulated from one another, the microlaminations being substantially aligned in a predetermined orientation and pressed into the desired configuration, the pressed core exhibiting a packing factor in excess of 85%.
Claim 34
Dependent Claim
57 words
A molded magnetic core comprising a plurality of magnetic alloy microlaminations, each of said microlaminations having been heat treated to improve the magnetic characteristics thereof, and magnetically insulated from one another, the microlaminations being substantially aligned in a predetermined orientation and pressed into the desired configuration, the pressed core exhibiting a packing factor in excess of 85%.
Claim 35
Dependent Claim
55 words
A microlamination suitable for use in molded magnetic components comprising a magnetic alloy in the form of an elongated parallelopiped of rectangular cross-section, the microlamination having been heat treated to improve the magnetic characteristics compared to the as-severed magnetic characteristics of the alloy and having a magnetically insulating coating covering the surface of the microlamination.
Claim 36
Dependent Claim
55 words
A microlamination suitable for use in molded magnetic components comprising a magnetic alloy in the form of an elongated parallelopiped of rectangular cross-section, the microlamination having been heat treated to improve the magnetic characteristics compared to the as-severed magnetic characteristics of the alloy and having a magnetically insulating coating covering the surface of the microlamination.
Claim 37
Dependent Claim
43 words
The method of claim 27 in which each of the microlaminations has dimensions within the range between about 0.05 and about 0.20 inch in length, about 0.005 and about 0.05 inch in width and from about 0.002 to about 0.02 inch in thickness.
Claim 38
Dependent Claim
43 words
The method of claim 28 in which each of the microlaminations has dimensions within the range between about 0.05 and about 0.20 inch in length, about 0.005 and about 0.05 inch in width and from about 0.002 to about 0.02 inch in thickness.
Claim 39
Dependent Claim
43 words
The method of claim 29 in which each of the microlaminations has dimensions within the range between about 0.05 and about 0.20 inch in length, about 0.005 and about 0.05 inch in width and from about 0.002 to about 0.02 inch in thickness.
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) | 1979-04-06 | 1979-10-06 | 1980-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-06 | 1983-10-06 | 1984-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-06 | 1987-10-06 | 1988-04-06 | $7700.00 | Window Closed / Lapsed |