US2890440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording system
Assignee: Monroe Calculating Machine Co
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Filing: 1954-10-07
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Granted: 1959-06-09
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Expires: 1974-10-07
Abstract
No abstract record available.
Inventors
- 👤 Burkhart William Henry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:54
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/14; G11B20/1488; G11B20/1492
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) | 1962-06-08 | 1962-12-08 | 1963-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-06-08 | 1966-12-08 | 1967-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-06-08 | 1970-12-08 | 1971-06-09 | $7700.00 | Window Closed / Lapsed |