US4079430A
Expired / Lapsed
US
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Magnetic head
Assignee: TDK Corp
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Filing: 1976-02-10
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Granted: 1978-03-14
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Expires: 1996-02-10
Abstract
Abstract Amorphous metal alloys are employed in a magnetic head as core materials in the present invention. Such alloys are generally composed of M and Y, wherein M is at least one of Fe, Ni and Co and Y is at least one of P, B, C and Si. The amorphous metal alloys used are marked by a combination of the desirable properties of conventional permalloy with those of conventional ferrites.
Inventors
- 👤 Hiroki Fujishima
- 👤 Kazuo Ohya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:01
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/147; H01F1/153; H01F1/15383; G; G11; G11B; G11B5/00; G11B5/127; G11B5/147
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
120 words
In a magnetic head comprising at least one head element, which head element comprises a core in the form of a ring and at least one magnetic coil, which core is composed of a magnetic core body discontinuous at at least one gap extending from the outer peripheral to the inner peripheral surfaces of the ring shaped core and a spacer inserted into each said gap, a coil, a magnetic flux being applied from the coil received by the coil from a part of magnetic recording medium in contact with the discontinuous part of said core body at said one gap, the improvement comprising employing as said core body a metal which is at least a 50% amorphous metal alloy.
Claim 2
Dependent Claim
120 words
In a magnetic head comprising at least one head element, which head element comprises a core in the form of a ring and at least one magnetic coil, which core is composed of a magnetic core body discontinuous at at least one gap extending from the outer peripheral to the inner peripheral surfaces of the ring shaped core and a spacer inserted into each said gap, a coil, a magnetic flux being applied from the coil received by the coil from a part of magnetic recording medium in contact with the discontinuous part of said core body at said one gap, the improvement comprising employing as said core body a metal which is at least a 50% amorphous metal alloy.
Claim 3
Dependent Claim
91 words
A magnetic head according to claim 1, in which said metal body is an amorphous metal alloy of the general formula: MaYb wherein M is at least one metal selected from the group consisting of iron, nickel and cobalt and Y is at least one element selected from the group consisting of phosphorous, boron, carbon and silicon, and wherein the percentage represented by atomic percentages in a and b are respectively selected from about 60 to about 95 and 5 to 40 with the proviso that a plus b equals 100.
Claim 4
Dependent Claim
87 words
A magnetic head according to claim 1, in which said metal body is amorphous metal alloy of the general formula: MaYb wherein M is a combination of nickel with either of palladium or platinum, and Y is at least one element selected from the group consisting of phosphorous and boron, and wherein the percentages represented by atomic percentages in a and b are respectively selected from about 60 to about 95 and from about 5 to about 40 with the proviso that a plus b equals 100.
Claim 5
Dependent Claim
18 words
A magnetic head according to claim 2, in which M is Fe and Y is P and C.
Claim 6
Dependent Claim
18 words
A magnetic head according to claim 2, in which M is Fe and Ni and Y is P.
Claim 7
Dependent Claim
16 words
A magnetic head according to claim 2, in which M is Co and Y is P.
Claim 8
Dependent Claim
18 words
A magnetic head according to claim 2, in which M is Fe and Y is P and B.
Claim 9
Dependent Claim
20 words
A magnetic head according to claim 2, in which M is Fe and Ni and Y is P and B.
Claim 10
Dependent Claim
61 words
A magnetic head according to claim 1, in which said metal body exhibits a coercive force of not more than 0.2 Oe, a maximum magnetic flux density of not less than 5,500 Gauss, a specific resistivity of not less than 150 × 10 -6 -cm, an initial permeability of not less than 20,000, and Vickers hardness of not less than 600.
Claim 11
Dependent Claim
30 words
A magnetic head according to claim 2, in which M and Y are present in a proportion corresponding to the eutectic composition of the components making up M and Y.
Claim 12
Dependent Claim
30 words
A magnetic head according to claim 3, in which M and Y are present in a proportion corresponding to the eutectic composition of the components making up M and Y.
Claim 13
Dependent Claim
21 words
A magnetic head according to claim 2, wherein a is from 79 to 92 and b is from 21 to 8.
Claim 14
Dependent Claim
17 words
A magnetic head according to claim 1, wherein said metal is at least a 75% amorphous alloy.
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) | 1981-03-13 | 1981-09-12 | 1982-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-13 | 1985-09-12 | 1986-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-13 | 1989-09-12 | 1990-03-14 | $7700.00 | Window Closed / Lapsed |