US4246619A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic transducer head
Assignee: Victor Company of Japan Ltd
•
Filing: 1979-01-11
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Granted: 1981-01-20
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Expires: 1999-01-11
Abstract
Abstract An electromagnetic transducer head for a tape recording and reproducing system comprises a pair of generally U-shaped single crystalline ferrite cores having their first legs secured together and their second legs spaced from each other to form a magnetic gap in which a wafer of glossy material is provided. Each of the ferrite cores has crystal planes (211), (110) and (111). The magnetic gap is aligned to the crystal plane (111) and the second legs of the cores are shaped to provide a tape contact surface which is parallel with the crystal plane (211). The crystal plane (110) is at right angles to the planes (211) and (111) and forms a passage for magnetic flux. The crystallographic axis <110> of each core extends at an angle to the magnetic gap so as to meet the axis <110> of the other core at a point aligned with the tape contact face.
Inventors
- 👤 Shiro Hirai
- 👤 Atsushi Nei
- 👤 Kunihide Sakai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:51
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/193; G11B5/133; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49034; Y10T29/49048; Y10T29/49055
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
151 words
An electromagnetic transducer head comprising a pair of single-crystalline ferrite half core elements each having crystal planes (211), (111) and (110) which are at right angles to each other, said core elements being secured together to form a magnetic circuit with a magnetic gap therein, said magnetic gap lying in a plane which is substantially parallel with said crystal plane (111), said core elements forming a tape contact face which is parallel with said crystal plane (211) and intersecting the plane of said magnetic gap at right angles, said core elements forming a common surface substantially parallel with said crystal plane (110), each of said core elements having a crystallographic axis <110> extending at an angle to the plane of said magnetic gap to intersect the crystallogrphic axis <110> of the other core element at a point lying in said tape contact face, and a coil wound on said magnetic circuit.
Claim 2
Dependent Claim
151 words
An electromagnetic transducer head comprising a pair of single-crystalline ferrite half core elements each having crystal planes (211), (111) and (110) which are at right angles to each other, said core elements being secured together to form a magnetic circuit with a magnetic gap therein, said magnetic gap lying in a plane which is substantially parallel with said crystal plane (111), said core elements forming a tape contact face which is parallel with said crystal plane (211) and intersecting the plane of said magnetic gap at right angles, said core elements forming a common surface substantially parallel with said crystal plane (110), each of said core elements having a crystallographic axis <110> extending at an angle to the plane of said magnetic gap to intersect the crystallogrphic axis <110> of the other core element at a point lying in said tape contact face, and a coil wound on said magnetic circuit.
Claim 3
Dependent Claim
100 words
An electromagnetic transducer head as claimed in claim 1, wherein each of said core elements comprises a generally U-shaped ferrite core, the first leg of the U-shape of each core being secured to the first leg of the U shape of the other core and the second leg of each core being spaced from the second leg of the other core to form said magnetic gap, said first and second legs of each core forming a common surface which is flush with the common surface formed by the other core, said common surfaces being parallel with said crystal plane (110).
Claim 4
Dependent Claim
34 words
An electromagnetic transducer head as claimed in claim 1 or claim 2, wherein, a line perpendicular to the plane of said gap is inclined at an angle less than 10° to said common surface.
Claim 5
Dependent Claim
15 words
An electromagnetic transducer head as claimed in claim 1, wherein said angle is approximately 55°.
Claim 6
Dependent Claim
27 words
An electromagnetic transducer head as claimed in any one of claims 1, 2 or 4, further comprising a spacer of fused material provided in said magnetic gap.
Claim 7
Dependent Claim
29 words
An electromagnetic transducer head as claimed in any one of claims 1, 2 or 4, wherein said half core elements have a positive magnetic anisotropic constant K 1 .
References Cited (Backward Citations)
US3810245A
Cited
US3931642A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-20 | 1984-07-21 | 1985-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-20 | 1988-07-21 | 1989-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-20 | 1992-07-21 | 1993-01-20 | $7700.00 | Window Closed / Lapsed |