US3140474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic memory drum
Assignee: Unisys Corp
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Filing: 1960-07-13
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Granted: 1964-07-07
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Expires: 1980-07-13
Abstract
No abstract record available.
Inventors
- 👤 Leshner Ervin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 22:00
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/58; G11B5/60
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
99 words
A MAGNETIC MEMORY DRUM COMPRISING, IN COMBINATION, A CLOSED STATIONARY MEMBER OF SLIGHTLY FRUSTO-CONICAL CONFIGURATION HAVING A PLURALITY OF MAGNETIC HEADS MOUNTED IN THE CURVED PORTION THEREOF, A ROTATABLE MEMBER OF FRUSTO-CONICAL CONFIGURATION CORRESPONDING TO SAID STATIONARY MEMBER AND SUBSTANTIALLY COAXIAL THEREWITH, HAVING A LAYER OF MAGNETIZABLE MATERIAL ON A CURVED SURFACE THEREOF OPPOSITE SAID MAGNETIC HEADS AND HAVING ALSO A NORMAL STARTING POSITION AND A NORMAL OPERATING POSITION LATERALLY SPACED THEREFROM, SLEEVE BEARINGS SUPPORTING SAID ROTATING MEMBER IN SAID STARTING POSITION AND A FLUID BEARING BETWEEN SAID CURVED SURFACES SUPPORTING SAID ROTATING MEMBER IN SAID NORMAL OPERATING POSITION.
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) | 1967-07-07 | 1968-01-06 | 1968-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-07-07 | 1972-01-06 | 1972-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-07-07 | 1976-01-06 | 1976-07-07 | $7700.00 | Window Closed / Lapsed |