Patent US3813766A successfully refreshed from Google Patents.
US3813766A
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Process for manufacture of a magnetic transducer using a pre-existing unitary foil
Assignee: International Business Machines Corp
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Filing: 1971-12-20
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Granted: 1974-06-04
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Expires: 1991-12-20
Abstract
Abstract Magnetic transducing heads capable of reading and writing magnetic information in the form of a pattern of magnetization on a magnetic recording medium are provided utilizing a unitary structure of magnetic sheet metal foil and conductive, nonmagnetic metal foil and thin film deposition techniques. In the preferred embodiment, the transducing heads consist of a monolithic sandwich of thin metallic magnetic foil forming a magnetic core enclosing a conductive non-magnetic metal foil exciting winding. The transducer is prepared from a prefabricated unitary laminate of magnetic metal foil and conductive metal foil which laminate is shaped into a magnetic head by, for example, photolithographic and deposition techniques.
Inventors
- 👤 G Brock
- 👤 W Mccormick
- 👤 S Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:47
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/1272; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49048; Y10T29/49052; Y10T29/49055
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
131 words
The method of forming a magnetic transducer element including a magnetically permeable core portion and an exciting winding from unitary foil, a complete core having a pair of pole tips defining a transducing gap area and also having a back gap area, including the steps of: obtaining a pre-existing unitary foil, said unitary foil being in the form of at least two metal foils joined together in a substantially monolithic structure, at least one foil being magnetically permeable and at least one foil being nonmagnetic and conductive; and then shaping said unitary foil into a transducer element by subtractive processes so that said magnetic foil portion of said unitary foil provides a core portion of said transducer element and said conductive foil portion of said unitary foil provides an exciting winding.
Claim 2
Independent Claim
131 words
The method of forming a magnetic transducer element including a magnetically permeable core portion and an exciting winding from unitary foil, a complete core having a pair of pole tips defining a transducing gap area and also having a back gap area, including the steps of: obtaining a pre-existing unitary foil, said unitary foil being in the form of at least two metal foils joined together in a substantially monolithic structure, at least one foil being magnetically permeable and at least one foil being nonmagnetic and conductive; and then shaping said unitary foil into a transducer element by subtractive processes so that said magnetic foil portion of said unitary foil provides a core portion of said transducer element and said conductive foil portion of said unitary foil provides an exciting winding.
Claim 3
Dependent Claim
40 words
The method of claim 1 wherein said unitary foil consists of only two metal foils and wherein the magnetic core is completed by deposition of additional magnetic material in conjunction with the magnetically permeable foil portion of said unitary foil.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein the subtractive process utilized in shaping said unitary foil is photoetching.
Claim 5
Dependent Claim
42 words
The method of claim 1 wherein said unitary foil consists of only two metal foils and wherein the magnetic core is completed by the addition of a second magnetic foil in conjunction with the magnetically permeable foil portion of said unitary foil.
Claim 6
Dependent Claim
17 words
The method of claim 4 wherein the subtractive process utilized in shaping said unitary foil is photoetching.
Claim 7
Independent Claim
118 words
The method of forming a magnetic transducer element including a magnetically permeable core portion and an exciting winding from unitary foil, said core having a transducing gap area and a back gap area, including the steps of: obtaining a pre-existing unitary foil, said unitary foil being in the form of three metal foils joined together in a substantially monolithic structure, said three foils including two spaced-apart magnetically permeable foils with nonmagnetic, conductive foil therebetween; and then shaping said unitary foil into a transducer element by subtractive processes so that said magnetic foil portions of said unitary foil provide a core portion of said transducer element and said conductive foil portion of said unitary foil provides an exciting winding.
Claim 8
Independent Claim
118 words
The method of forming a magnetic transducer element including a magnetically permeable core portion and an exciting winding from unitary foil, said core having a transducing gap area and a back gap area, including the steps of: obtaining a pre-existing unitary foil, said unitary foil being in the form of three metal foils joined together in a substantially monolithic structure, said three foils including two spaced-apart magnetically permeable foils with nonmagnetic, conductive foil therebetween; and then shaping said unitary foil into a transducer element by subtractive processes so that said magnetic foil portions of said unitary foil provide a core portion of said transducer element and said conductive foil portion of said unitary foil provides an exciting winding.
Claim 9
Dependent Claim
17 words
The method of claim 6 wherein said subtractive process utilized in shaping said unitary foil is photoetching.
Claim 10
Dependent Claim
25 words
The method of clAim 6 wherein said two magnetic layers of said unitary foil are joined by magnetically permeable material at the back gap area.
Claim 11
Dependent Claim
52 words
The method of claim 6 wherein the magnetically permeable foil portions of said unitary foil have a thickness in the range of about 0.05 mil to about 2.0 mils and said conductive foil portion of said unitary foil has a thickness in the range of about 0.02 mil to about 0.10 mil.
Claim 12
Dependent Claim
51 words
The method of claim 9 wherein said subtractive process utilized in shaping said unitary foil is photoetching and wherein the magnetic foil portions of said unitary foil have a thickness of about 0.5 mil each and said conductive foil portion of said unitary foil has a thickness of about 0.04 mil.
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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) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |