Patent US4855857A successfully refreshed from Google Patents.
US4855857A
Expired / Lapsed
US
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Magnetic disc cartridge with spindle abutment plate
Assignee: Fujifilm Holdings Corp
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Filing: 1988-12-02
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Granted: 1989-08-08
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Expires: 2008-12-02
Abstract
Abstract A drive spindle abutment plate 14 centrally mounted on the inner wall of a protective envelope enclosing a floppy disc is formed by a surface layer 15 of macromolecular polyethylene or the like and an interposed base layer 16 of relatively hard material such as polyethylene terephthalate. Indentation by the end of the spindle during use is thus minimized to preserve the necessary gap between the envelope and the disc core 6, thereby preventing the core from scratching against the envelope and disturbing the disc rotation.
Inventors
- 👤 Tsuyoshi Ono
- 👤 Kunihira Seto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:31
CPC Classifications
G; G11; G11B; G11B23/00; G11B23/02; G11B23/03; G11B23/033; G11B23/0332; G11B23/0014; G11B23/0021; G11B23/0028; G11B23/0035
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
127 words
A magnetic disc cartridge including an abutment plate (14) adapted to contact the end of a spindle (10) of magnetic disc sheet rotating means, said plate being disposed at the center of a wall (3) of a protective envelope in which a magnetic disc sheet (4) is rotatably accommodated, characterized in that: said abutment plate comprises a surface layer (15) for engaging the spindle end and a base layer (16) made of a material harder than said surface layer and interposed between said wall and said surface layer, said surface layer being bonded to said wall of said envelope by adhesive applied to both surfaces of said base layer, wherein said base layer has a sufficiently high compressive strength to resist indentation thereof by said spindle end.
Claim 2
Dependent Claim
127 words
A magnetic disc cartridge including an abutment plate (14) adapted to contact the end of a spindle (10) of magnetic disc sheet rotating means, said plate being disposed at the center of a wall (3) of a protective envelope in which a magnetic disc sheet (4) is rotatably accommodated, characterized in that: said abutment plate comprises a surface layer (15) for engaging the spindle end and a base layer (16) made of a material harder than said surface layer and interposed between said wall and said surface layer, said surface layer being bonded to said wall of said envelope by adhesive applied to both surfaces of said base layer, wherein said base layer has a sufficiently high compressive strength to resist indentation thereof by said spindle end.
Claim 3
Dependent Claim
17 words
A magnetic disc cartridge according to claim 1, wherein said base layer is made of polyethylene terephthalate.
References Cited (Backward Citations)
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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) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |