US4935834A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shutter spring for disk cartridge
Assignee: 3M Co
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Filing: 1988-11-14
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Granted: 1990-06-19
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Expires: 2008-11-14
Abstract
Abstract A disk cartridge for a rotatable recording disk includes a slidable shutter for providing access to the recording disk through the disk cartridge. A unique mounting for a return spring for the shutter allows the return spring to be of a maximum length which allows increased control of the forces generated by the return spring. The disk cartridge is further provided with a locking mechanism for preventing movement of the recording disk within the disk cartridge during storage.
Inventors
- 👤 Robert A. Muehlhausen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:26
CPC Classifications
G; G11; G11B; G11B23/00; G11B23/02; G11B23/03; G11B23/0301; G11B23/0308; G11B23/0306
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
154 words
A return spring mounting for a disc cartridge including a housing enclosing a recording disc and having a substantially 90 degree corner adjacent the disc and a shutter means slideable between an open position providing access to the disc through the housing and a closed position preventing access to the disc for protection of the disc, said return spring mounting including: a helical extension spring having a first end and a second end wherein said first end is attached to said housing substantially at said corner of said housing and wherein said second end of said spring is attached to said shutter means at a point substantially as far removed from said spring first end as possible to maximize the length of said spring in the direction of movement of said shutter means between said first position and said second position to provide increased control over the range of forces produced by said spring.
Claim 2
Dependent Claim
154 words
A return spring mounting for a disc cartridge including a housing enclosing a recording disc and having a substantially 90 degree corner adjacent the disc and a shutter means slideable between an open position providing access to the disc through the housing and a closed position preventing access to the disc for protection of the disc, said return spring mounting including: a helical extension spring having a first end and a second end wherein said first end is attached to said housing substantially at said corner of said housing and wherein said second end of said spring is attached to said shutter means at a point substantially as far removed from said spring first end as possible to maximize the length of said spring in the direction of movement of said shutter means between said first position and said second position to provide increased control over the range of forces produced by said spring.
Claim 3
Dependent Claim
59 words
A return spring mounting according to claim 1 wherein said shutter means includes a carrier slideably connected to said housing to move said shutter means between said open and said closed positions, and wherein said second end of said spring is attached to said carrier at a point substantially as far removed from said spring first end as possible.
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) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |