US3639700A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multielement magnetic head of all oxide or sintered qualities
Assignee: Panasonic Holdings Corp
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Filing: 1970-03-16
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Granted: 1972-02-01
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Expires: 1990-03-16
Abstract
Abstract A multielement magnetic head for magnetic recording and/or reproducing operations. The tape-engaging face of the head includes magnetic cores each having a gap, preformed sectioned spacers of nonmagnetic material surrounding the magnetic cores, and a shield plate of magnetic material disposed between the adjacent cores. The materials of all the members composing the tape-engaging face are sintered oxides.
Inventors
- 👤 Takashi Shiraki
- 👤 Sadao Masuoka
- 👤 Minoru Morita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:19
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/29; G11B5/295
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
90 words
A multielement magnetic head including a tape-engaging face, said tape-engaging face comprising magnetic cores each having a gap, yokes each having a coil wound thereon and joined to said cores on the legs thereof, preformed sectioned spacers surrounding said magnetic cores, said spacers of nonmagnetic material and insulating magnetically said magnetic cores for a supporting casing, and a shield plate of magnetic material having a greater width than said cores and disposed between the adjacent cores, the materials forming all of said elements other than said coils being sintered oxides.
Claim 2
Dependent Claim
90 words
A multielement magnetic head including a tape-engaging face, said tape-engaging face comprising magnetic cores each having a gap, yokes each having a coil wound thereon and joined to said cores on the legs thereof, preformed sectioned spacers surrounding said magnetic cores, said spacers of nonmagnetic material and insulating magnetically said magnetic cores for a supporting casing, and a shield plate of magnetic material having a greater width than said cores and disposed between the adjacent cores, the materials forming all of said elements other than said coils being sintered oxides.
Claim 3
Dependent Claim
31 words
A multielement magnetic head as defined in claim 1, wherein the material forming said cores and said shield plate is ferrite and said nonmagnetic material is ceramics composed mainly of Fe2O3.
Claim 4
Dependent Claim
37 words
A multielement magnetic head as defined in claim 1, wherein the material forming said cores and said shield plate is ferrite and said nonmagnetic material is a sintered oxide composed of Al2O3, MgO, SiO2, ZrO2, BeO, TiO2.
Claim 5
Dependent Claim
36 words
A multielement magnetic head as defined in claim 1, wherein fixing frames are provided to integrally hold said cores and said shield plate with spacers interposed therebetween, said fixing frames being formed of a sintered oxide.
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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |