US2485539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic sound recorder utilizing varying cathode currents
Assignee: Individual
•
Filing: 1945-06-06
•
Granted: 1949-10-18
•
Expires: 1965-06-06
Abstract
No abstract record available.
Inventors
- 👤 Weiss Shirley Irving
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:29
CPC Classifications
G; G11; G11B; G11B5/00
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) | 1952-10-17 | 1953-04-18 | 1953-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-10-17 | 1957-04-18 | 1957-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-10-17 | 1961-04-18 | 1961-10-18 | $7700.00 | Window Closed / Lapsed |