US2817829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording system
Assignee: Underwood Corp
•
Filing: 1953-07-23
•
Granted: 1957-12-24
•
Expires: 1973-07-23
Abstract
No abstract record available.
Inventors
- 👤 Lubkin Samuel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:14
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/16
Claims Analysis
Total Claims: 0
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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) | 1960-12-23 | 1961-06-24 | 1961-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-12-23 | 1965-06-24 | 1965-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-12-23 | 1969-06-24 | 1969-12-24 | $7700.00 | Window Closed / Lapsed |