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US4520078A Expired / Lapsed US ⏱️ 0.0 years remaining

Cores for electromagnetic apparatus and methods of fabrication

Assignee: Electric Power Research Institute
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Filing: 1981-06-08
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Granted: 1985-05-28
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Expires: 2001-06-08
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Abstract

Abstract A number of metal cores especially suitable for use in an electrical induction device such as a transformer are disclosed herein along with respective methods of making these cores. In accordance with each of these methods, the appropriate metal material is initially provided and thereafter formed into an unsolidified, preliminary shape. Thereafter, while the material is in its preliminary shape, it is densified, preferably by means of explosion bonding, whereby to improve its permeability and saturation field characteristics. In one embodiment, a metal material is initially provided as a continuous strip. In another embodiment, the metal material is initially provided as a number of plates and still in another, preferred embodiment, amorphous metal particulate material is utilized. In this latter embodiment, the orientation of the particulate material is controlled to further improve the permeability and saturation field characteristics of the ultimately formed core.

Inventors

  • 👤 Mario Rabinowitz
  • 👤 E. Robert Perry

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 22:14
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/02; H01F41/0206; H01F41/0213; H01F41/0226; Y; Y10; Y10S; Y10S264/00; Y10S264/58; Y10S428/00; Y10S428/922; Y10S428/9335; Y10S428/94; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49075; Y10T29/49076; Y10T29/49078; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12639

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 99 words
A method of making an amorphous metal core for use in an electrical induction device such as a transformer, said method comprising the steps of: initially providing appropriate amorphous metal material in the form of a continuous strip for use as said core; winding said continuous strip of material into an unsolidified, preliminary shape; and thereafter, while said unsolidified wound strip of material is in said preliminary shape, explosion bonding said material into a solidified final shape without causing the amorphous material to recrystallize, whereby to increase its density substantially and therefore improve its permeability and field saturation characteristics.
Claim 2
Independent Claim 99 words
A method of making an amorphous metal core for use in an electrical induction device such as a transformer, said method comprising the steps of: initially providing appropriate amorphous metal material in the form of a continuous strip for use as said core; winding said continuous strip of material into an unsolidified, preliminary shape; and thereafter, while said unsolidified wound strip of material is in said preliminary shape, explosion bonding said material into a solidified final shape without causing the amorphous material to recrystallize, whereby to increase its density substantially and therefore improve its permeability and field saturation characteristics.
Claim 3
Dependent Claim 9 words
A product according to the process of claim 1.
Claim 4
Independent Claim 139 words
A method of making an amorphous metal core for use in an electrical induction device such as a transformer, said method comprising the steps of: initially providing appropriate amorphous metal material for use as said core; forming said material into an unsolidified, preliminary shape; and thereafter, while said material is in said preliminary shape, explosion bonding said material into a solidified final shape without causing the amorphous material to recrystallize, whereby to increase its density substantially and therefore improve its permeability and field saturation characteristics, said initially provided material being provided in the form of a plurality of separate plates, each of which is substantially thinner than the final thickness of said core but has the same shape of the latter in plan view, and wherein said plates are placed in a stack to form said unsolidified preliminary shape.
Claim 5
Independent Claim 139 words
A method of making an amorphous metal core for use in an electrical induction device such as a transformer, said method comprising the steps of: initially providing appropriate amorphous metal material for use as said core; forming said material into an unsolidified, preliminary shape; and thereafter, while said material is in said preliminary shape, explosion bonding said material into a solidified final shape without causing the amorphous material to recrystallize, whereby to increase its density substantially and therefore improve its permeability and field saturation characteristics, said initially provided material being provided in the form of a plurality of separate plates, each of which is substantially thinner than the final thickness of said core but has the same shape of the latter in plan view, and wherein said plates are placed in a stack to form said unsolidified preliminary shape.
Claim 6
Dependent Claim 9 words
A product according to the process of claim 3.

References Cited (Backward Citations)

US2384215A Cited
GB960340A Cited
US3220103A Cited
US3432279A Cited
US4201837A Cited
US4325895A Cited
US4385944A Cited
US4364020A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-05-27 1988-11-26 1989-05-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-05-27 1992-11-26 1993-05-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-05-27 1996-11-26 1997-05-28 $7700.00 Window Closed / Lapsed

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