US4017899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single-track video ferrite record/reproduce head and manufacturing method therefor
Assignee: Eastman Kodak Co
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Filing: 1976-03-22
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Granted: 1977-04-12
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Expires: 1996-03-22
Abstract
Abstract Two magnetic ferrite pieces having longitudinal channels formed in the side faces thereof are bonded together with a gapping substance so that the resultant channels form a window. The bonded pieces are precisely slotted to a depth below the apex of the window to form a narrow track-defining comb-like array. The resulting slots are adapted to receive gap-protecting compatible ceramic support material which is so chosen as to wear slightly faster than the ferrite surfaces. In one embodiment, the slots contain ceramic-convertible glass which is devitrified by firing the array. The assembly is then processed to form a ceramic-ferrite-ceramic or ceramic-ferrite transducer sandwich which may be further processed to form part of a magnetic record and/or reproduce head.
Inventors
- 👤 John F. Bagby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:53
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/255
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
161 words
A narrow, single-track video magnetic head comprising: a. first and second ferrite parts, each having an arcuately contoured front part and a back part; b. non-magnetic means bonding said ferrite front and back parts together, thereby to form transducer front and back gaps between said ferrite front and back parts, said ferrite front parts at said front gap being 10 mils or less in width and substantially less in width than said ferrite back parts at said back gap, the side walls of said front part having ferrite wall portions that extend across said front gap substantially parallel to each other on both sides of said front gap; and c. separate ceramic pieces, mounted in parallel and glass-bonded to both said ferrite wall portions at both sides of said front gap, for protecting said gap from deteriorating, said ceramic having slightly less wear resistance than said ferrite such that said ceramic wears slightly faster than said ferrite first and second parts.
Claim 2
Dependent Claim
161 words
A narrow, single-track video magnetic head comprising: a. first and second ferrite parts, each having an arcuately contoured front part and a back part; b. non-magnetic means bonding said ferrite front and back parts together, thereby to form transducer front and back gaps between said ferrite front and back parts, said ferrite front parts at said front gap being 10 mils or less in width and substantially less in width than said ferrite back parts at said back gap, the side walls of said front part having ferrite wall portions that extend across said front gap substantially parallel to each other on both sides of said front gap; and c. separate ceramic pieces, mounted in parallel and glass-bonded to both said ferrite wall portions at both sides of said front gap, for protecting said gap from deteriorating, said ceramic having slightly less wear resistance than said ferrite such that said ceramic wears slightly faster than said ferrite first and second parts.
Claim 3
Dependent Claim
19 words
The structure of claim 1 wherein the width-wise dimensions of said ceramic parts are both less than 10 mils.
Claim 4
Dependent Claim
180 words
A narrow, single-track video magnetic head for use with a rotating head video tape recorder, comprising: a. first and second ferrite parts, each having an arcuately contoured track-defining front part of 10 mils or less in width and a back part; b. non-magnetic means bonding said track-defining front parts together, thereby to form a transducer gap between said ferrite front parts, said ferrite front parts at said gap being substantially thinner than said ferrite back parts, said track-defining front parts having side walls that extend across said gap substantially parallel to each other on both sides of said gap; and c. side wall supporting ceramic pieces, glass-bonded in parallel to both side track-defining front parts at said side walls of said gap thereby to form a ceramic-ferrite-ceramic sandwich substantially equal in width to said back parts, for protecting said gap from deterioration due to the crumbling of said side walls as a magnetic tape pounds thereagainst, said ceramic having slightly less wear resistance than said ferrite such that said ceramic wears slightly faster than said ferrite first and second parts.
Claim 5
Dependent Claim
180 words
A narrow, single-track video magnetic head for use with a rotating head video tape recorder, comprising: a. first and second ferrite parts, each having an arcuately contoured track-defining front part of 10 mils or less in width and a back part; b. non-magnetic means bonding said track-defining front parts together, thereby to form a transducer gap between said ferrite front parts, said ferrite front parts at said gap being substantially thinner than said ferrite back parts, said track-defining front parts having side walls that extend across said gap substantially parallel to each other on both sides of said gap; and c. side wall supporting ceramic pieces, glass-bonded in parallel to both side track-defining front parts at said side walls of said gap thereby to form a ceramic-ferrite-ceramic sandwich substantially equal in width to said back parts, for protecting said gap from deterioration due to the crumbling of said side walls as a magnetic tape pounds thereagainst, said ceramic having slightly less wear resistance than said ferrite such that said ceramic wears slightly faster than said ferrite first and second parts.
References Cited (Backward Citations)
US3775571A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-11 | 1980-10-11 | 1981-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-11 | 1984-10-11 | 1985-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-11 | 1988-10-11 | 1989-04-12 | $7700.00 | Window Closed / Lapsed |