Patent US4587714A successfully refreshed from Google Patents.
US4587714A
Expired / Lapsed
US
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Manufacture of motor with split back magnet array
Assignee: Unisys Corp
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Filing: 1984-01-03
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Granted: 1986-05-13
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Expires: 2004-01-03
Abstract
Abstract A disc drive arrangement including RW head actuator driven by an improved voice coil motor, having ceramic back-magnets which are subdivided to give improved magnetic characteristics and operation (increased working flux and an increase in efficiency and effective power acceleration for given current--e.g., thus decreasing "access time").
Inventors
- 👤 Frank I. Morris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:44
CPC Classifications
G; G11; G11B; G11B21/00; G11B21/02; H; H02; H02K; H02K41/00; H02K41/02; H02K41/035; H02K41/0352; H02K41/0354; H02K41/0356; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49005; Y10T29/4902; Y10T29/49021; Y10T29/49025; Y10T29/49075
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
44 words
A method of fabricating an improve actuator motor for a disc drive actuator, this motor including magnet means, the magnet means comprising a slab of ferro-magnetic ceramic; the method including: splitting this slab at least once to form an array of identical magnet parts.
Claim 2
Independent Claim
44 words
A method of fabricating an improve actuator motor for a disc drive actuator, this motor including magnet means, the magnet means comprising a slab of ferro-magnetic ceramic; the method including: splitting this slab at least once to form an array of identical magnet parts.
Claim 3
Dependent Claim
30 words
The method of claim 1 wherein the motor is a voice-coil motor and wherein the magnet parts so formed are mounted in virtual abutment, each on a respective backing plate.
Claim 4
Dependent Claim
8 words
The product of the method in claim 2.
Claim 5
Dependent Claim
11 words
The method of claim 2 wherein the backing plates are joined.
Claim 6
Dependent Claim
28 words
The method of claim 4 wherein the backing plates are disposed in aligned abutment within the motor so as to present the so-split magnet parts as virtually touching.
Claim 7
Dependent Claim
8 words
The product of the method in claim 5.
Claim 8
Dependent Claim
8 words
The pioduct of the method in claim 1.
Claim 9
Independent Claim
55 words
A method of making improved actuator motive means including associated magnet means, this magnet means comprising one or several ceramic magnet-slabs, this method comprising: subdividing at least one of the slabs into two or more identical sub-portions; and recombining these sub-portions as a composite magnet, disposed in the actuator motive means, to enhance flux density.
Claim 10
Independent Claim
55 words
A method of making improved actuator motive means including associated magnet means, this magnet means comprising one or several ceramic magnet-slabs, this method comprising: subdividing at least one of the slabs into two or more identical sub-portions; and recombining these sub-portions as a composite magnet, disposed in the actuator motive means, to enhance flux density.
Claim 11
Dependent Claim
35 words
The method of claim 8 wherein the motive means is a voice-coil motor and wherein each said magnet-slab so subdivided has its sub-portions reassembled and mounted in virtual abutment, each on a respective backing plate.
Claim 12
Dependent Claim
17 words
The method of claim 9 wherein the slab comprises a back magnet slab cut into identical halves.
Claim 13
Dependent Claim
25 words
The method of claim 10 wherein each subdivided slab is thereafter a back magnet so-halved and each half is bonded on a respective backing plate.
Claim 14
Dependent Claim
31 words
The method of claim 11 wherein the backing plates are disposed in aligned abutment within a disk drive actuator motor so as to present the so-split magnet halves as virtually touching.
Claim 15
Dependent Claim
8 words
The product of the method in claim 12.
Claim 16
Dependent Claim
8 words
The product of the method in claim 10.
Claim 17
Dependent Claim
8 words
The product of the method in claim 8.
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) | 1989-05-12 | 1989-11-11 | 1990-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-12 | 1993-11-11 | 1994-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-12 | 1997-11-11 | 1998-05-13 | $7700.00 | Window Closed / Lapsed |