US4538258A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Record
Assignee: Nidec Instruments Corp
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Filing: 1983-08-26
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Granted: 1985-08-27
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Expires: 2003-08-26
Abstract
Abstract A record (12) comprising a convex protrusion (12a) at its center, one or more protrusions (12b) extending perpendicularly from the plane of the record at its circumferential edge, and a recording area between the center and the circumferential edge. The protrusions engage similar indentations (3b, 3e) formed in a turntable to facilitate centering and holding the record for playing and to prevent rotational slippage.
Inventors
- 👤 Haruyoshi Miyako
- 👤 Kiyoteru Arima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:54
CPC Classifications
G; G11; G11B; G11B17/00; G11B17/02; G11B17/022; G11B17/028; G11B17/0284; G11B23/00; G11B23/0014; G11B23/0021
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
103 words
A record for play on a turntable having a central concave indentation and one or more circumferentially varying indentations on a circumference of said turntable, comprising: a flat disc (12); a convex protrusion (12a) substantially at the center of said disc for engaging said central indentation and centering said disc; and one or more protrusions (12b) formed on the circumferential periphery of said disc for engaging said circumferentially varying indentations and for rotating said disc as said turntable rotates, said peripheral protrusions varying circumferentially around said disc, insertable into one of said indentations and contactable with a circumferential side of said one indentation.
Claim 2
Dependent Claim
103 words
A record for play on a turntable having a central concave indentation and one or more circumferentially varying indentations on a circumference of said turntable, comprising: a flat disc (12); a convex protrusion (12a) substantially at the center of said disc for engaging said central indentation and centering said disc; and one or more protrusions (12b) formed on the circumferential periphery of said disc for engaging said circumferentially varying indentations and for rotating said disc as said turntable rotates, said peripheral protrusions varying circumferentially around said disc, insertable into one of said indentations and contactable with a circumferential side of said one indentation.
Claim 3
Dependent Claim
21 words
A record, as recited in claim 1, wherein separate circumferential protrusions are formed on both opposing flat sides of said disc.
Claim 4
Dependent Claim
24 words
A record, as recited in claim 1, further comprising a recorded portion of said disc between said central convex protrusion and said circumferential protrusions.
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) | 1988-08-26 | 1989-02-25 | 1989-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-26 | 1993-02-25 | 1993-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-26 | 1997-02-25 | 1997-08-27 | $7700.00 | Window Closed / Lapsed |