US2638539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for converting electrical frequency variations into amplitude variations
Assignee: RCA Corp
•
Filing: 1949-05-28
•
Granted: 1953-05-12
•
Expires: 1969-05-28
Abstract
No abstract record available.
Inventors
- 👤 Carmen L Cuccia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:33
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/02; H01J31/04; H03; H03D; H03D3/00; H03D3/32
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-05-11 | 1956-11-10 | 1957-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-11 | 1960-11-10 | 1961-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-11 | 1964-11-10 | 1965-05-12 | $7700.00 | Window Closed / Lapsed |