Patent US4754351A successfully refreshed from Google Patents.
US4754351A
Expired / Lapsed
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Method and apparatus for controlling radial disk displacement in Winchester disk drives
Assignee: CIT Group Business Credit Inc
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Filing: 1985-03-25
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Granted: 1988-06-28
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Expires: 2005-03-25
Abstract
Abstract In a Winchester hard disk drive assembly having at least one disk rotatably disposed on a cylindrical spindle, the improvement compromising spacer means interposed between the inner diameter of said at least one disk and the outer diameter of said cylindrical spindle, said spacer means defining a clearance between said at least one disk and said spindle and adhesive means for adhesively securing said spacer means between said spindle, and said at least one disk, whereby a substantially uniform and contiguous clearance is maintained about the circumference of the spindle upon thermally induced differential expansion of the disk, and whereby said disk will be substantially prevented from abutting the outer circumferential wall of the spindle.
Inventors
- 👤 Harold T. Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:09
CPC Classifications
G; G11; G11B; G11B17/00; G11B17/02; G11B17/038; F; F16; F16D; F16D1/00; F16D1/06; G11B23/00; G11B23/0014; G11B23/0021; G11B23/0028; G11B33/00; G11B33/14; G11B33/1446; G11B33/1473
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
161 words
In a Winchester hard disk drive assembly comprising at least one disk disposed on a rotatable, cylindrical spindle, the improvement comprising: resilient spacer means intermittently disposed between the inner diameter of said at least one disk and the outer diameter of said spindle, for forming a substantially uniform and continuous annular air gap between the inner diameter of said disk and the outer diameter of said spindle, said air gap providing clearance between said disk and said spindle to prevent said inner diameter of said disk from abutting said outer diameter of said spindle due to thermally induced differential expansion of said disk and spindle; wherein said spacer means comprises strips of resilient material extending longitudinally with respect to the longitudinal axis of said spindle along at least some portion of the outer wall of said spindle interposed between said spindle and said at least one disk; and means for adhesively securing said spacer means between said spindle and said disk.
Claim 2
Dependent Claim
161 words
In a Winchester hard disk drive assembly comprising at least one disk disposed on a rotatable, cylindrical spindle, the improvement comprising: resilient spacer means intermittently disposed between the inner diameter of said at least one disk and the outer diameter of said spindle, for forming a substantially uniform and continuous annular air gap between the inner diameter of said disk and the outer diameter of said spindle, said air gap providing clearance between said disk and said spindle to prevent said inner diameter of said disk from abutting said outer diameter of said spindle due to thermally induced differential expansion of said disk and spindle; wherein said spacer means comprises strips of resilient material extending longitudinally with respect to the longitudinal axis of said spindle along at least some portion of the outer wall of said spindle interposed between said spindle and said at least one disk; and means for adhesively securing said spacer means between said spindle and said disk.
Claim 3
Dependent Claim
23 words
The improvement as claimed in claim 1 wherein said resilient material has a modulus of elasticity not greater than 65,000 lbs/in 2 .
Claim 4
Dependent Claim
18 words
The improvement as claimed in claim 1 wherein said resilient material comprises a polytetrafluoroethylene material such as TELFON.
Claim 5
Dependent Claim
23 words
The improvement as claimed in claim 1 wherein said strips are spaced substantially equidistant from one another about the circumference of said spindle.
Claim 6
Dependent Claim
18 words
The improvement as claimed in claim 1 wherein said strips have a nominal thickness of approximately 0.006 inches.
Claim 7
Dependent Claim
134 words
In a Winchester disk drive assembly having at least one disk rotatably disposed on a cylindrical spindle the improvement comprising: a plurality of spacer strips of fluorocarbon resin material interposed between the inner diameter of said at least one disk and the outer diameter of said cylindrical spindle, said strips forming a substantially uniform and continuous air gap between the inner diameter of said disk and the outer diameter of said spindle, said air gap providing sufficient clearance between said disk and said spindle to prevent said inner diameter of said disk from abutting said outer diameter of said spindle due to thermally induced differential expansion of said disk and said spindle; and adhesive means for adhesively securing said spacer strips longitudinally along at least some portion of the outer wall of said spindle.
Claim 8
Dependent Claim
134 words
In a Winchester disk drive assembly having at least one disk rotatably disposed on a cylindrical spindle the improvement comprising: a plurality of spacer strips of fluorocarbon resin material interposed between the inner diameter of said at least one disk and the outer diameter of said cylindrical spindle, said strips forming a substantially uniform and continuous air gap between the inner diameter of said disk and the outer diameter of said spindle, said air gap providing sufficient clearance between said disk and said spindle to prevent said inner diameter of said disk from abutting said outer diameter of said spindle due to thermally induced differential expansion of said disk and said spindle; and adhesive means for adhesively securing said spacer strips longitudinally along at least some portion of the outer wall of said spindle.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-28 | 1991-12-28 | 1992-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-28 | 1995-12-28 | 1996-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-28 | 1999-12-28 | 2000-06-28 | $7700.00 | Window Closed / Lapsed |