Patent EP0186773A2 successfully refreshed from Google Patents.
Patent US6400835B1 successfully refreshed from Google Patents.
US4129937A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making grounded transducer for magnetic record disks
Assignee: International Business Machines Corp
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Filing: 1977-08-25
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Granted: 1978-12-19
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Expires: 1997-08-25
Abstract
Abstract A transducer particularly for use with magnetic record disks and composed of cores having transducing gaps therein adapted to contact or be in near contact with a record disk at the gaps and composed also of outriggers on the sides of the cores for increasing the surface area of the transducer adapted to contact or be in near contact with a record disk. The cores are of ferrite and have windings thereon, and the outriggers are of ceramic, both the ferrite and ceramic being nonconductive electrically. One of the outriggers is provided with a plating of electrically conductive material on a side surface with the plating being coterminous with the surface of the outrigger adapted to contact the record disk or be in near contact with it, and a ground lead is connected with the plating so as to ground any electrostatic charge on the surface of the disk.
Inventors
- 👤 Gerald R. Knutson
- 👤 Karl A. Shidler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 06:26
CPC Classifications
G; G11; G11B; G11B17/00; G11B17/02; G11B17/022; G11B17/028; G11B17/032; G11B23/00; G11B23/50; G11B23/505; G11B5/00; G11B5/10; G11B5/11; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49041; Y10T29/49048; Y10T29/49055
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
182 words
In a method of making a magnetic head assembly, the steps which comprise, making a ferrite core having a transducer gap in a working surface of the ferrite core, making an outrigger of ceramic material, plating the outrigger on at least a pair of contiguous surfaces thereof with a layer of electrically conducting material, bonding said outrigger to said ferrite core with one of said plated surfaces being disposed between the ferrite core and said outrigger and with the other of said plates surfaces forming a continuation of said working surface of said ferrite core, and lapping said working surface of said ferrite core and the continuation thereof provided by said outrigger so as to form an accurate working surface of the magnetic head assembly and to remove the plating on said surface of said outrigger forming a continuation of said working surface of said ferrite core leaving the conductive plating between said ferrite core and said outrigger which may provide a conductive path for static electricity carried by a magnetic medium contacting or lying in close proximity to said working surface.
Claim 2
Dependent Claim
182 words
In a method of making a magnetic head assembly, the steps which comprise, making a ferrite core having a transducer gap in a working surface of the ferrite core, making an outrigger of ceramic material, plating the outrigger on at least a pair of contiguous surfaces thereof with a layer of electrically conducting material, bonding said outrigger to said ferrite core with one of said plated surfaces being disposed between the ferrite core and said outrigger and with the other of said plates surfaces forming a continuation of said working surface of said ferrite core, and lapping said working surface of said ferrite core and the continuation thereof provided by said outrigger so as to form an accurate working surface of the magnetic head assembly and to remove the plating on said surface of said outrigger forming a continuation of said working surface of said ferrite core leaving the conductive plating between said ferrite core and said outrigger which may provide a conductive path for static electricity carried by a magnetic medium contacting or lying in close proximity to said working surface.
Claim 3
Dependent Claim
32 words
A method of making a magnetic head assembly as set forth in claim 1, said working surface being a planar surface and said lapping being conducted to make said surface accurately planar.
Claim 4
Dependent Claim
30 words
A method of making a magnetic head assembly as set forth in claim 1, said working surface being spherical and said lapping being conducted to render said surface accurately spherical.
Claim 5
Dependent Claim
193 words
In a method of making a magnetic head assembly for use with a moving magnetic medium, the steps which comprise: making a core member of magnetic and electrically non-conductive material having a transducer gap in a working surface of the core member, making an outrigger member of electrically non-conductive, non-magnetic material also having a working surface, plating one of said members with a layer of electrically conducting material on at least a pair of contiguous surfaces thereof and including its said working surface, bonding said members together with one of said plated surfaces being disposed between said members and with said working surfaces forming a continuation of each other, and removing a thin layer of said working surfaces of said core member and said outrigger member so as to form an accurate working surface of the magnetic head assembly and to thereby remove the plating on said working surface of said member having the plating leaving the conductive plating between said members which may provide a conductive discharge path for static electricity carried by a moving magnetic medium contacting or lying in close proximity to said working surface of the magnetic head assembly.
Claim 6
Dependent Claim
193 words
In a method of making a magnetic head assembly for use with a moving magnetic medium, the steps which comprise: making a core member of magnetic and electrically non-conductive material having a transducer gap in a working surface of the core member, making an outrigger member of electrically non-conductive, non-magnetic material also having a working surface, plating one of said members with a layer of electrically conducting material on at least a pair of contiguous surfaces thereof and including its said working surface, bonding said members together with one of said plated surfaces being disposed between said members and with said working surfaces forming a continuation of each other, and removing a thin layer of said working surfaces of said core member and said outrigger member so as to form an accurate working surface of the magnetic head assembly and to thereby remove the plating on said working surface of said member having the plating leaving the conductive plating between said members which may provide a conductive discharge path for static electricity carried by a moving magnetic medium contacting or lying in close proximity to said working surface of the magnetic head assembly.
Claim 7
Dependent Claim
46 words
The method of making a magnetic head assembly as set forth in claim 4, in which the plating is accomplished on said core member which is electrically non-conductive and non-magnetic, said removal of a this layer of said working surfaces being accomplished by an abrading operation.
References Cited (Backward Citations)
US3668775A
Cited
US3846840A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-12-18 | 1982-06-19 | 1982-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-18 | 1986-06-19 | 1986-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-18 | 1990-06-19 | 1990-12-19 | $7700.00 | Window Closed / Lapsed |