US3582572A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transducer head with grain oriented silicon-iron core
Assignee: IIT CORP
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Filing: 1968-07-22
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Granted: 1971-06-01
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Expires: 1988-07-22
Abstract
Abstract A microgap magnetic transducer head having a core formed of a binary alloy of silicon and iron (preferably from about 3 percent to 7 percent silicon) provides a sharply defined gap of a thickness not more than about one micron, and makes possible a higher magnetic flux saturation density as well as superior wearing qualities as compared with prior magnetic heads, especially for use in a longitudinal scan video transducer system. Advantageous oriented core configurations and core mounting means are also disclosed.
Inventors
- 👤 Marvin Camras
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:22
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49034
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
26 words
A head according to claim 1 with said side piece being welded to said under surface adjacent said gap defining edge face of said core piece.
Claim 2
Dependent Claim
43 words
A head according to claim 1 with said polar extremity having a record medium engaging surface of silicon-iron opposite said under surface and having a depth dimension between said surfaces at said gap defining edge face of not more than about 1 mil.
Claim 3
Dependent Claim
36 words
A head according to claim 1 with said core piece being Formed from grain oriented silicon-iron sheet material having a preferred direction corresponding to the direction of the working magnetic flux path in said polar extremity.
Claim 4
Dependent Claim
42 words
A magnetic head having a magnetic core with a coupling region for coupling the core to a traveling magnetic record medium, said magnetic core being formed of a grain-oriented hydrogen-annealed silicon-iron alloy having a hardness of at least 50 Rockwell (B2 Scale).
Claim 5
Dependent Claim
56 words
A magnetic head according to claim 5, wherein, said silicon-iron alloy has been annealed by heating in a dry hydrogen atmosphere to a temperature above the Curie point of said alloy and during cooling from said temperature has been subjected to a magnetic field applied in the direction of the working flux path of said core.
Claim 6
Dependent Claim
40 words
A magnetic head according to claim 5, wherein, said silicon-iron alloy has a silicon content of at least about 6.5 percent silicon with the balance iron and minor impurities, and said alloy has a resistivity of at least 80 microhm-cms.
Claim 7
Dependent Claim
77 words
A magnetic head having a magnetic core with a coupling region for coupling the core to a traveling magnetic record medium, a polar region adjacent said coupling region presenting a surface of a binary silicon-iron alloy of from about 3 percent to 7 percent silicon and the balance essentially iron for slidable contacting engagement by said record medium, said magnetic core being characterized by having a gap of a thickness of not more than about 1 micron.
Claim 8
Dependent Claim
60 words
A head according to claim 8, wherein said magnetic core has a material thickness of 4 mils or less, said gap has a thickness less than 1 micron, and a layer of electrically conductive material having a resistivity less than 2 microhm-centimeters is disposed in close conforming relation to exterior surfaces of said magnetic core except at such coupling region.
Claim 9
Dependent Claim
62 words
A head in accordance with claim 8 with mounting means for the core having a record medium engaging surface generally flush with the record medium engaging surface of the magnetic core but being of a material subject to substantially more rapid wear in response to sliding contact with the record medium than the material of said record engaging surface of said core.
Claim 10
Dependent Claim
53 words
A head in accordance with claim 10 wherein said mounting means comprises a layer of electrically conductive material disposed in close conforming relation to the said magnetic core except at said record engaging surface and side pieces are fastened to said core at opposite sides of said magnetic core adjacent said coupling region.
Claim 11
Dependent Claim
21 words
A head in accordance with claim 11, wherein said side pieces are C-shaped and are fastened to said core by welds.
Claim 12
Dependent Claim
41 words
A head according to claim 8, wherein said magnetic core includes laminations of said binary silicon-iron alloy and side pieces also of said alloy, said side pieces being flanged to provide a pocket therebetween with said core laminations filling said pocket.
Claim 13
Dependent Claim
21 words
A head according to claim 13, wherein said laminations and side pieces are annealed, grain-oriented and unstressed sheets of said alloy.
Claim 14
Dependent Claim
18 words
A head according to claim 8, wherein said binary silicon-iron alloy contains less than 0.05 percent of carbon.
Claim 15
Dependent Claim
26 words
A head according to claim 15, wherein said alloy has been annealed by heating in a dry hydrogen atmosphere at about 2000* F. and cooled slowly.
Claim 16
Dependent Claim
35 words
A head according to claim 8, wherein said silicon-iron alloy contains about 6.5 percent silicon and has a resistivity of the order of 80 microhm-centimeters and a saturation density of the order of 20,000 gauss.
Claim 17
Dependent Claim
31 words
A head according to claim 17, wherein said gap has a thickness of less than 1 micron and said silicon-iron alloy has a Rockwell (B2 scale) hardness of at least 50.
Claim 18
Dependent Claim
14 words
A head according to claim 18, wherein said core is in an unstressed condition.
Claim 19
Dependent Claim
43 words
A head according to claim 8, wherein said core includes said silicon-iron Alloy in the form of a C-shaped side pieces with the grain of the silicon-iron alloy at said polar region oriented substantially at right angles to the plane of said gap.
Claim 20
Dependent Claim
26 words
A head according to claim 20, wherein said core includes laminations between said side pieces of a high permeability alloy having the lowest possible coercive force.
Claim 21
Dependent Claim
24 words
A head according to claim 20, wherein certain of said C-shaped sheets are channel-shaped in cross section and provide pole pieces defining said gap.
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) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |