Patent US4631620A successfully refreshed from Google Patents.
US4631620A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic disk cartridge
Assignee: Fujifilm Holdings Corp
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Filing: 1985-03-18
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Granted: 1986-12-23
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Expires: 2005-03-18
Abstract
Abstract The magnetic disk of a magnetic disk cartridge is provided with a center core assembly which comprises a main core, an upper core with grooves on one side for engagement with the ridges of a ridged, resilient ring which is provided on its non-engagement side with double-sided adhesive tape for holding the disk onto the ring. The disk attached to the ring can be held lightly but securely between the upper and main parts of the center core without the need to apply excessive clamping force.
Inventors
- 👤 Kengo Oishi
- 👤 Shingo Katagiri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:22
CPC Classifications
G; G11; G11B; G11B23/00; G11B23/0014; G11B23/0021; G11B23/0028; G11B23/0035
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
142 words
A magnetic disk cartridge comprising a disk-shaped recording medium formed of a flexible material; a center core disposed at the center of said recording medium for the rotation thereof which comprises a main core, a resilient ring and an upper core arranged concentrically one on the other in that order, with the recording medium being held between the main core and the resilient ring; and a cartridge casing which integrally houses said recording medium and said center core; wherein the resilient ring has radially extending ridges formed on the side which contacts the upper core and is provided on its other side with double-sided adhesive tape, and the upper core is provided with a plurality of grooves extending radially across the whole of the surface which comes into contact with the resilient ring for engagement with the ridges of the resilient ring.
Claim 2
Dependent Claim
142 words
A magnetic disk cartridge comprising a disk-shaped recording medium formed of a flexible material; a center core disposed at the center of said recording medium for the rotation thereof which comprises a main core, a resilient ring and an upper core arranged concentrically one on the other in that order, with the recording medium being held between the main core and the resilient ring; and a cartridge casing which integrally houses said recording medium and said center core; wherein the resilient ring has radially extending ridges formed on the side which contacts the upper core and is provided on its other side with double-sided adhesive tape, and the upper core is provided with a plurality of grooves extending radially across the whole of the surface which comes into contact with the resilient ring for engagement with the ridges of the resilient ring.
Claim 3
Dependent Claim
22 words
The magnetic disk cartridge according to claim 1 in which the resilient ring is a corrugated ring with the corrugations running circumferentially.
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) | 1989-12-22 | 1990-06-23 | 1990-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-22 | 1994-06-23 | 1994-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-22 | 1998-06-23 | 1998-12-23 | $7700.00 | Window Closed / Lapsed |