US4158580A
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 characterized by coating particles of annealed low carbon ferrous alloy with a coating of hydrated magnesium silicate.
Inventors
- 👤 William T. Reynolds
- 👤 Norman M. Pavlik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:30
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/20; H01F1/22; H01F1/24; Y; Y10; Y10S; Y10S264/00; Y10S264/58
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
151 words
A method of making pressed magnetic core components for use in electrical apparatus, comprising the steps of: (a) severing microlaminations from thin, flat strips of ferromagnetic alloys having an elongated rectangular cross-section and up to about 0.20 inch in length, (b) annealing the microlaminations in decarburizing atmosphere at a temperature range of from about 1000° F. to about 1650° F. for about 30 minutes in moist hydrogen having a dew point of about +120° F. to improve the magnetic characteristics by reducing carbon content to less than 0.010%, (c) coating the microlaminations with a layer of hydrated magnesium silicate whereby to provide a chemically stable non-volatile, non-flammable, non-toxic compact having low die and punch friction packing factors, (d) compressing microlaminations into a solidified compact, and (e) annealing the solidified compact at a temperature of from about 537° C. to about 900° C. to obtain high permeability and low coercive force values.
Claim 2
Independent Claim
151 words
A method of making pressed magnetic core components for use in electrical apparatus, comprising the steps of: (a) severing microlaminations from thin, flat strips of ferromagnetic alloys having an elongated rectangular cross-section and up to about 0.20 inch in length, (b) annealing the microlaminations in decarburizing atmosphere at a temperature range of from about 1000° F. to about 1650° F. for about 30 minutes in moist hydrogen having a dew point of about +120° F. to improve the magnetic characteristics by reducing carbon content to less than 0.010%, (c) coating the microlaminations with a layer of hydrated magnesium silicate whereby to provide a chemically stable non-volatile, non-flammable, non-toxic compact having low die and punch friction packing factors, (d) compressing microlaminations into a solidified compact, and (e) annealing the solidified compact at a temperature of from about 537° C. to about 900° C. to obtain high permeability and low coercive force values.
Claim 3
Dependent Claim
25 words
The method of claim 1 in which annealing at step (b) occurs in the temperature range of from about 537° C. to about 900° C.
Claim 4
Dependent Claim
17 words
The method of claim 2 in which at step (b) the annealing temperature is about 800° C.
Claim 5
Dependent Claim
30 words
The method of claim 3 in which the hydrated magnesium silicate is applied to the microlaminations by blending hydrated magnesium silicate at about 0.5% of the weight of the microlaminations.
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) | 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 |