Patent US2774646A successfully refreshed from Google Patents.
US2774646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording method
Assignee: International Business Machines Corp
•
Filing: 1951-12-31
•
Granted: 1956-12-18
•
Expires: 1971-12-31
Abstract
No abstract record available.
Inventors
- 👤 Byron E Phelps
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:47
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/02; G06; G06K; G06K7/00; G06K7/08; G11B5/008; H; H04; H04N; H04N5/00; H04N5/76; H04N5/78; H04N5/782
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1959-12-18 | 1960-06-18 | 1960-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-12-18 | 1964-06-18 | 1964-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-12-18 | 1968-06-18 | 1968-12-18 | $7700.00 | Window Closed / Lapsed |