US2458641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for controlling frequency characteristics in sound recording
Assignee: RCA Corp
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Filing: 1945-05-08
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Granted: 1949-01-11
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Expires: 1965-05-08
Abstract
No abstract record available.
Inventors
- 👤 Rettinger Michael
- 👤 Singer Kurt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:48
CPC Classifications
H; H03; H03G; H03G5/00; H03G5/16; H03G5/18; H03G5/22
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) | 1952-01-11 | 1952-07-12 | 1953-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-01-11 | 1956-07-12 | 1957-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-01-11 | 1960-07-12 | 1961-01-11 | $7700.00 | Window Closed / Lapsed |