US5020213A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing a head core slider
Assignee: NGK Insulators Ltd
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Filing: 1989-12-14
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Granted: 1991-06-04
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Expires: 2009-12-14
Abstract
Abstract Method for producing a head core slider for a rigid magnetic disk drive, including a ferrite slider body having a pair of air bearing portions which have a predetermined height and are spaced apart from each other in a transverse direction perpendicular to a direction of extension thereof, and further including a pair of ferrite yoke portions formed integrally with the slider body. The yoke portions cooperate with the slider body to form a first and a second closed magnetic path and define therebetween a first and a second magnetic gap. The slider body and the yoke portions cooperate to provide a first and a second track portion in which the first and second magnetic gaps are open, respectively. The first and second track portions have sliding surfaces which have the same height as the air bearing portions. The first track portion is used exclusively for an information writing operation, while the second track portion is used exclusively for an information reading operation. Where the first and second track portions have a same width, the first and second magnetic gaps have different sizes. Where the two magnetic gaps have a same size, the two track portions have different widths. Alternatively, the two track portions have different widths while the two magnetic gaps have different sizes.
Inventors
- 👤 Michael I. Aronoff
- 👤 Soichiro Matsuzawa
- 👤 Nobuhiro Terada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:19
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/48; G11B5/58; G11B5/60; G11B5/6005; G11B5/187; G11B5/1871; G11B5/23; G11B5/488; G11B5/4886; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49041; Y10T29/49048; Y10T29/49052; Y10T29/49055
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
359 words
A method of producing a core slider for a rigid magnetic disk drive, comprising the steps of: forming a primary groove in at least one of abutting surfaces of a first and a second ferrite block, by etching said at least one abutting surface through a first etching mask applied thereto; forming a plurality of secondary recesses in at least one of said abutting surfaces of the first and second ferrite blocks, by etching said at least one abutting surface through a second etching mask applied thereto; butting and bonding together said first and second ferrite blocks at said abutting surfaces, to form an integral ferrite bar which has a closed magnetic path defined between said first and second blocks, said ferrite bar having a first magnetic gap corresponding to a total depth of said primary groove, and a second magnetic gap corresponding to a total depth of said primary groove and said secondary recesses; applying a third etching mask to a surface of said ferrite bar in which said first and second magnetic gaps are open, and etching said surface of the ferrite bar to form a plurality of parallel spaced-apart air bearing portions on said first ferrite block, and a plurality of track portions which extend from said air bearing portions, respectively, and between said first and second ferrite blocks, said air bearing portions and said track portions having a predetermined height, and said track portions having a same width in a transverse direction perpendicular to a direction of extension of said air bearing portions, said first magnetic gap being open in one of each pair of two adjacent track portions of said plurality of track portions, while said second magnetic gap being open in the other of said each pair of two adjacent track portions; and cutting said ferrite bar to prepare at least one core slider, each of which includes a slider body having the two adjacent air bearing portions corresponding to said adjacent two track portions, and a pair of yoke portions which are formed on said second ferrite block and which cooperate with said slider body to form said adjacent two track portions.
Claim 2
Independent Claim
359 words
A method of producing a core slider for a rigid magnetic disk drive, comprising the steps of: forming a primary groove in at least one of abutting surfaces of a first and a second ferrite block, by etching said at least one abutting surface through a first etching mask applied thereto; forming a plurality of secondary recesses in at least one of said abutting surfaces of the first and second ferrite blocks, by etching said at least one abutting surface through a second etching mask applied thereto; butting and bonding together said first and second ferrite blocks at said abutting surfaces, to form an integral ferrite bar which has a closed magnetic path defined between said first and second blocks, said ferrite bar having a first magnetic gap corresponding to a total depth of said primary groove, and a second magnetic gap corresponding to a total depth of said primary groove and said secondary recesses; applying a third etching mask to a surface of said ferrite bar in which said first and second magnetic gaps are open, and etching said surface of the ferrite bar to form a plurality of parallel spaced-apart air bearing portions on said first ferrite block, and a plurality of track portions which extend from said air bearing portions, respectively, and between said first and second ferrite blocks, said air bearing portions and said track portions having a predetermined height, and said track portions having a same width in a transverse direction perpendicular to a direction of extension of said air bearing portions, said first magnetic gap being open in one of each pair of two adjacent track portions of said plurality of track portions, while said second magnetic gap being open in the other of said each pair of two adjacent track portions; and cutting said ferrite bar to prepare at least one core slider, each of which includes a slider body having the two adjacent air bearing portions corresponding to said adjacent two track portions, and a pair of yoke portions which are formed on said second ferrite block and which cooperate with said slider body to form said adjacent two track portions.
Claim 3
Independent Claim
263 words
A method of producing a core slider for a rigid magnetic disk drive, comprising the steps of: forming a groove in at least one of abutting surfaces of a first and a second ferrite block; butting and bonding together said first and second ferrite blocks at said abutting surfaces, to form an integral ferrite bar which has a closed magnetic path defined between said first and second blocks, said ferrite bar having a magnetic gap corresponding to a depth of said groove; applying an etching mask to a surface of said ferrite bar in which said magnetic gap is open, and etching said surface of the ferrite bar to form a plurality of spaced-apart air bearing portions on said first ferrite block, and a plurality of track portions which extend from said air bearing portions, respectively, and between said first and second ferrite blocks, said air bearing portions and said track portions having a predetermined height, one of each pair of two adjacent track portions of said plurality of track portions having a larger width in a transverse direction perpendicular to a direction of extension of said air bearing portions, than the other of said each pair of two adjacent track portions; and cutting said ferrite bar to prepare at least one core slider, each of which includes a slider body having the two adjacent air bearing portions corresponding to said two adjacent track portions, and a pair of yoke portions which are formed on said second ferrite block and which cooperate with said slider body to form said two adjacent track portions.
Claim 4
Independent Claim
263 words
A method of producing a core slider for a rigid magnetic disk drive, comprising the steps of: forming a groove in at least one of abutting surfaces of a first and a second ferrite block; butting and bonding together said first and second ferrite blocks at said abutting surfaces, to form an integral ferrite bar which has a closed magnetic path defined between said first and second blocks, said ferrite bar having a magnetic gap corresponding to a depth of said groove; applying an etching mask to a surface of said ferrite bar in which said magnetic gap is open, and etching said surface of the ferrite bar to form a plurality of spaced-apart air bearing portions on said first ferrite block, and a plurality of track portions which extend from said air bearing portions, respectively, and between said first and second ferrite blocks, said air bearing portions and said track portions having a predetermined height, one of each pair of two adjacent track portions of said plurality of track portions having a larger width in a transverse direction perpendicular to a direction of extension of said air bearing portions, than the other of said each pair of two adjacent track portions; and cutting said ferrite bar to prepare at least one core slider, each of which includes a slider body having the two adjacent air bearing portions corresponding to said two adjacent track portions, and a pair of yoke portions which are formed on said second ferrite block and which cooperate with said slider body to form said two adjacent track portions.
Claim 5
Independent Claim
377 words
A method of producing a core slider for a rigid magnetic disk drive, comprising the steps of: forming a primary groove in at least one of abutting surfaces of a first and a second ferrite block, by etching said at least one abutting surface through a first etching mask applied thereto; forming a plurality of secondary recesses in at least one of said abutting surfaces of the first and second ferrite blocks, by etching said at least one abutting surface through a second etching mask applied thereto; butting and bonding together said first and second ferrite blocks at said abutting surfaces, to form an integral ferrite bar which has a closed magnetic path defined between said first and second blocks, said ferrite bar having a first magnetic gap corresponding to a total depth of said primary groove, and a second magnetic gap corresponding to a total depth of said primary groove and said secondary recesses; applying a third etching mask to a surface of said ferrite bar in which said first and second magnetic gaps are open, and etching said surface of the ferrite bar to form a plurality of spaced-apart air bearing portions on said first ferrite block, and a plurality of track portions which extend from said air bearing portions, respectively, and between said first and second ferrite blocks, said air bearing portions and said track portions having a predetermined height, said first magnetic gap being open in one of each pair of two adjacent track portions of said plurality of track portions, while said second magnetic gap being open in the other of said each pair of two adjacent track portions, said other of said each pair of two adjacent track portions having a larger width in a transverse direction perpendicular to a direction of extension of said air bearing portions, than said one of said each pair of two adjacent track portions; and cutting said ferrite bar to prepare at least one core slider, each of which includes a slider body having the two adjacent air bearing portions corresponding to said two adjacent track portions, and a pair of yoke portions which are formed on said second ferrite block and which cooperate with said slider body to form said two adjacent track portions.
Claim 6
Independent Claim
377 words
A method of producing a core slider for a rigid magnetic disk drive, comprising the steps of: forming a primary groove in at least one of abutting surfaces of a first and a second ferrite block, by etching said at least one abutting surface through a first etching mask applied thereto; forming a plurality of secondary recesses in at least one of said abutting surfaces of the first and second ferrite blocks, by etching said at least one abutting surface through a second etching mask applied thereto; butting and bonding together said first and second ferrite blocks at said abutting surfaces, to form an integral ferrite bar which has a closed magnetic path defined between said first and second blocks, said ferrite bar having a first magnetic gap corresponding to a total depth of said primary groove, and a second magnetic gap corresponding to a total depth of said primary groove and said secondary recesses; applying a third etching mask to a surface of said ferrite bar in which said first and second magnetic gaps are open, and etching said surface of the ferrite bar to form a plurality of spaced-apart air bearing portions on said first ferrite block, and a plurality of track portions which extend from said air bearing portions, respectively, and between said first and second ferrite blocks, said air bearing portions and said track portions having a predetermined height, said first magnetic gap being open in one of each pair of two adjacent track portions of said plurality of track portions, while said second magnetic gap being open in the other of said each pair of two adjacent track portions, said other of said each pair of two adjacent track portions having a larger width in a transverse direction perpendicular to a direction of extension of said air bearing portions, than said one of said each pair of two adjacent track portions; and cutting said ferrite bar to prepare at least one core slider, each of which includes a slider body having the two adjacent air bearing portions corresponding to said two adjacent track portions, and a pair of yoke portions which are formed on said second ferrite block and which cooperate with said slider body to form said two adjacent track portions.
References Cited (Backward Citations)
US4381966A
Cited
US4843486A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-03 | 1994-12-03 | 1995-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-03 | 1998-12-03 | 1999-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-03 | 2002-12-03 | 2003-06-04 | $7700.00 | Window Closed / Lapsed |