US4780779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laminated sendust metal-in-gap video head
Assignee: Ampex Corp
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Filing: 1987-11-19
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Granted: 1988-10-25
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Expires: 2007-11-19
Abstract
Abstract An improved magnetic head structure which places a laminate at the gaps of the head, said laminate deposited on each substrate facing the gap, and comprising alternating layers of first and second magnetic materials, said first material having a higher coercivity than said second material.
Inventors
- 👤 Raghavan K. Pisharody
- 👤 Robert H. Ohe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:27
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/23; G11B5/235; G11B5/1875; G11B5/1877; G11B5/1878
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
116 words
A magnetic head assembly comprising a pair of opposite core members, said core members each having pole pieces at opposite ends, at least one pair of confronting pole pieces arranged to face a gap between said core members, each of said confronting pole pieces providing a substrate for receiving successive layers of a laminated material, said laminated material comprising alternating layers of at least first and second magnetic materials, said first magnetic material of a higher coercivity than the second magnetic material, each layer of the first magnetic material having a thickness ranging from 5 to 10 microinches, and each alternating layer of the second magnetic material having a thickness ranging from 1 to 5 microinches.
Claim 2
Dependent Claim
116 words
A magnetic head assembly comprising a pair of opposite core members, said core members each having pole pieces at opposite ends, at least one pair of confronting pole pieces arranged to face a gap between said core members, each of said confronting pole pieces providing a substrate for receiving successive layers of a laminated material, said laminated material comprising alternating layers of at least first and second magnetic materials, said first magnetic material of a higher coercivity than the second magnetic material, each layer of the first magnetic material having a thickness ranging from 5 to 10 microinches, and each alternating layer of the second magnetic material having a thickness ranging from 1 to 5 microinches.
Claim 3
Dependent Claim
29 words
A magnetic head assembly as claimed in claim 1 wherein the laminated material at each substrate comprises at least five alternating layers of said first and second magnetic materials.
Claim 4
Dependent Claim
16 words
A magnetic head assembly as claimed in claim 2 wherein the first magnetic material is Sendust.
Claim 5
Dependent Claim
16 words
A magnetic head assmmbly as claimed in claim 3 wherein the second magnetic material is permalloy.
Claim 6
Independent Claim
153 words
A method of providing a head structure on a magnetic head assembly comprising a pair of opposite core members, said core members each having pole pieces at opposite ends, at least one pair of confronting pole pieces arranged to face a gap between said core members, each of said confronting pole pieces providing a substrate for receiving successive layers of a laminated material, said method comprising the steps of: applying a first magnetic material of a relatively high coercivity to the substrate to a thickness ranging from 5 to 10 microinches; applying a second layer of a second magnetic material of relatively lower coercivity than the first material to the first layer of said first magnetic material on the substrate, said second material having a thickness ranging from 1 to 5 microinches; and applying alternating layers of said first and second material to each substrate to a thickness of at least five layers.
Claim 7
Independent Claim
153 words
A method of providing a head structure on a magnetic head assembly comprising a pair of opposite core members, said core members each having pole pieces at opposite ends, at least one pair of confronting pole pieces arranged to face a gap between said core members, each of said confronting pole pieces providing a substrate for receiving successive layers of a laminated material, said method comprising the steps of: applying a first magnetic material of a relatively high coercivity to the substrate to a thickness ranging from 5 to 10 microinches; applying a second layer of a second magnetic material of relatively lower coercivity than the first material to the first layer of said first magnetic material on the substrate, said second material having a thickness ranging from 1 to 5 microinches; and applying alternating layers of said first and second material to each substrate to a thickness of at least five layers.
Claim 8
Dependent Claim
33 words
A method of providing a head structure on a magnetic head assembly as claimed in claim 5 wherein in the step of applying the first magnetic material, Sendust is applied to the substrate.
Claim 9
Dependent Claim
37 words
A method of providing a head structure on a magnetic head assembly as claimed in claim 6 wherein in the step of applying the second magnetic material, permalloy is applied to the Sendust layer on the substrate.
References Cited (Backward Citations)
EP0206658A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-25 | 1992-04-25 | 1992-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-25 | 1996-04-25 | 1996-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-25 | 2000-04-25 | 2000-10-25 | $7700.00 | Window Closed / Lapsed |