Patent US4242710A successfully refreshed from Google Patents.
US4242710A
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Thin film head having negative magnetostriction
Assignee: International Business Machines Corp
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Filing: 1979-01-29
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Granted: 1980-12-30
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Expires: 1999-01-29
Abstract
Abstract A thin film inductive head is formed with nickel-iron binary alloy or nickel-iron-X ternary alloy pole pieces characterized by negative magnetostriction having a saturation magnetostriction coefficient in the range of -1×10 -6 to -5×10 -6 .
Inventors
- 👤 Robert D. Hempstead
- 👤 James B. Money
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:29
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3109
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
64 words
A thin film magnetic head assembly consisting: first and second magnetic pole pieces formed as unitary thin film layers said first pole piece being deposited directly on a substrate insulating material disposed between and separating said pole pieces; planar conductive coils in a substantially planar array disposed within said insulating material; said pole pieces being formed from a magnetic material characterized by negative magnetostriction.
Claim 2
Dependent Claim
64 words
A thin film magnetic head assembly consisting: first and second magnetic pole pieces formed as unitary thin film layers said first pole piece being deposited directly on a substrate insulating material disposed between and separating said pole pieces; planar conductive coils in a substantially planar array disposed within said insulating material; said pole pieces being formed from a magnetic material characterized by negative magnetostriction.
Claim 3
Dependent Claim
33 words
A thin film magnetic head assembly as in claim 1, wherein said magnetic material of said pole pieces has a saturation magnetostriction coefficient in the range of -1×10 -6 to -5×10 -6 .
Claim 4
Dependent Claim
36 words
A thin film magnetic head assembly as in claim 1, wherein said magnetic pole pieces are formed from a nickel-iron composition, with a nickel to iron ratio in the range of 81:19 to 84:16 by weight.
Claim 5
Dependent Claim
37 words
A thin film magnetic head assembly as in claim 1, wherein said magnetic pole pieces are formed from a ternary nickel-iron-X alloy, having a saturation magnetostriction coefficient in the range of -1×10 -6 to -5×10 -6 .
Claim 6
Dependent Claim
44 words
A thin film magnetic head assembly, as in claim 4, wherein the material X is from the group including boron, carbon, silicon, phosphorous, titanium, vanadium, chromium, cobalt, copper, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, and mercury.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-30 | 1984-06-30 | 1984-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-30 | 1988-06-30 | 1988-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-30 | 1992-06-30 | 1992-12-30 | $7700.00 | Window Closed / Lapsed |