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Patent US4940878A successfully refreshed from Google Patents.
US4940878A
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Anisotropic resistivity material and method of making same
Assignee: Northrop Grumman Corp
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Filing: 1988-12-15
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Granted: 1990-07-10
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Expires: 2008-12-15
Abstract
Abstract A material which exhibits different electrical resistivity in mutually perpendicular directions is formed by providing a base member of one metal and covering a surface of the base member with a second metal of a different composition. Thereafter, multiple passes are made with a high energy beam over the surface of the second metal to form a plurality of alloyed zones in the base metal with the resistivity of the alloyed zones being different than that of the adjacent base metal. A rotor for a dynamoelectric machine fabricated by such methods imparts a preferred direction to current flow to thereby eliminate large undesirable eddy currents and by tailoring the pattern of the higher resistivity zones, a machine may be provided which produces a self-compensating flux to minimize undesirable flux leakage common in such machines.
Inventors
- 👤 Bobby D. McKee
- 👤 Alvin H. Nakagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:03
CPC Classifications
H; H02; H02K; H02K31/00; B; B23; B23K; B23K26/00; B23K26/20; B23K26/21; B23K26/24; B23K26/244; B23K26/26; B23K26/32; B23K26/323; H01; H01C; H01C13/00; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
114 words
An anisotropic resistivity body made by the process of: (A) providing a base member, of a first metal, and having first and second surfaces; (B) placing a second metal on a first surface of said base member, said second metal having a different composition than said first metal; (C) making multiple passes over said surface with a high energy beam so as to cause, on each said pass, an alloyed zone to penetrate said base member from said first toward said second surface; and (D) removing an excess metal, including all of said second metal, on the surfaces of said base member so as to form a body having alternate zones of different resistivity.
Claim 2
Dependent Claim
114 words
An anisotropic resistivity body made by the process of: (A) providing a base member, of a first metal, and having first and second surfaces; (B) placing a second metal on a first surface of said base member, said second metal having a different composition than said first metal; (C) making multiple passes over said surface with a high energy beam so as to cause, on each said pass, an alloyed zone to penetrate said base member from said first toward said second surface; and (D) removing an excess metal, including all of said second metal, on the surfaces of said base member so as to form a body having alternate zones of different resistivity.
Claim 3
Dependent Claim
24 words
A body according to claim 1 wherein: (A) each said alloyed zone has a higher resistivity than that of the adjacent base member zone.
Claim 4
Dependent Claim
116 words
An anisotropic resistivity body made by the process of: (A) providing a base member, of copper, and having first and second surfaces; (B) placing a second metal on a first surface of said base member, said second metal having a different composition than said first metal and chosen from a group which includes nickel and aluminum; (C) making multiple passes over said surface with a high energy beam so as to cause, on each said pass, an alloyed zone to penetrate said base member from said first toward said second surface; and (D) removing any excess metal on the surfaces of said base member so as to form a body having alternate zones of different resistivity.
Claim 5
Dependent Claim
116 words
An anisotropic resistivity body made by the process of: (A) providing a base member, of copper, and having first and second surfaces; (B) placing a second metal on a first surface of said base member, said second metal having a different composition than said first metal and chosen from a group which includes nickel and aluminum; (C) making multiple passes over said surface with a high energy beam so as to cause, on each said pass, an alloyed zone to penetrate said base member from said first toward said second surface; and (D) removing any excess metal on the surfaces of said base member so as to form a body having alternate zones of different resistivity.
Claim 6
Dependent Claim
148 words
An anisotropic resistivity body made by the process of: (A) providing a base member, of a first metal, and having first and second surfaces; (B) placing a second metal on a first surface of said base member, said second metal having a different composition than said first metal; (C) placing a second metal on the second surface of said base member; (D) making multiple passes over said first surface so as to cause on each said pass an alloyed zone to penetrate said base member at least halfway to said second surface; (E) making multiple passes over said second surface so as to cause on each said pass an alloyed zone to penetrate said base member at least halfway to said first surface; and (F) removing any excess metal on the surfaces of said base member so as to form a body having alternate zones of different resistivity.
Claim 7
Dependent Claim
148 words
An anisotropic resistivity body made by the process of: (A) providing a base member, of a first metal, and having first and second surfaces; (B) placing a second metal on a first surface of said base member, said second metal having a different composition than said first metal; (C) placing a second metal on the second surface of said base member; (D) making multiple passes over said first surface so as to cause on each said pass an alloyed zone to penetrate said base member at least halfway to said second surface; (E) making multiple passes over said second surface so as to cause on each said pass an alloyed zone to penetrate said base member at least halfway to said first surface; and (F) removing any excess metal on the surfaces of said base member so as to form a body having alternate zones of different resistivity.
References Cited (Backward Citations)
US4468552A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-09 | 1994-01-08 | 1994-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-09 | 1998-01-08 | 1998-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-09 | 2002-01-08 | 2002-07-10 | $7700.00 | Window Closed / Lapsed |