US4158582A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making pressed magnetic core components
Assignee: ABB Inc USA
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Filing: 1978-04-14
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Granted: 1979-06-19
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Expires: 1998-04-14
Abstract
Abstract A method of making pressed magnetic core components having a low core loss property for use in electrical apparatus characterized by reannealing and repressing said components after initial annealing and pressing.
Inventors
- 👤 Robert F. Krause
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:25
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/20; H01F1/22; H01F1/24
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
100 words
A method of making pressed magnetic core components having improved magnetic characteristics for use in electrical apparatus, comprising the steps of: (a) forming microlaminations from ferrous alloy stock, (b) annealing said microlaminations in decarburizing and deoxidizing atmosphere to improve the magnetic characteristics and to reduce the carbon to less than 0.01%, (c) coating said microlaminates with electrically insulating material, (d) assembling said microlaminations within a mold of predetermined configuration, (e) compacting said microlaminations into the desired configuration of a magnetic core compact, (f) annealing said core to relieve stresses, and (g) recompacting said magnetizable compact to improve the magnetic characteristics.
Claim 2
Independent Claim
100 words
A method of making pressed magnetic core components having improved magnetic characteristics for use in electrical apparatus, comprising the steps of: (a) forming microlaminations from ferrous alloy stock, (b) annealing said microlaminations in decarburizing and deoxidizing atmosphere to improve the magnetic characteristics and to reduce the carbon to less than 0.01%, (c) coating said microlaminates with electrically insulating material, (d) assembling said microlaminations within a mold of predetermined configuration, (e) compacting said microlaminations into the desired configuration of a magnetic core compact, (f) annealing said core to relieve stresses, and (g) recompacting said magnetizable compact to improve the magnetic characteristics.
Claim 3
Dependent Claim
30 words
The method of claim 1 in which the material from which the microlaminations are formed in an iron alloy having a carbon content of from about 0.05% to about 0.15%.
Claim 4
Dependent Claim
42 words
The method of claim 1 in which each microlamination has dimensions within the range between about 0.05 and about 0.20 inch in length, from about 0.005 and about 0.05 inch in width, and from about 0.002 and about 0.02 inch in thickness.
Claim 5
Dependent Claim
26 words
The method of claim 1 in which the annealing step (b) occurs at a temperature in the range of about 1325° F. an about 1650° F.
Claim 6
Dependent Claim
21 words
The method of claim 4 in which the annealing step (b) occurs for a time period of up to 2 hours.
Claim 7
Dependent Claim
36 words
The method of claim 1 in which the annealing step (f) occurs at a temperature in the range of from about 1300° F. and about 1800° F. for from about 5 minutes to about 1 hour.
Claim 8
Dependent Claim
23 words
The method of claim 1 in which the recompaction step (g) occurs at a pressure in the range of 50,000 to 125,000 psi.
References Cited (Backward Citations)
US3848331A
Cited
US3948690A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-06-18 | 1982-12-18 | 1983-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-18 | 1986-12-18 | 1987-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-18 | 1990-12-18 | 1991-06-19 | $7700.00 | Window Closed / Lapsed |