US2439872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency responsive circuits
Assignee: RCA Corp
•
Filing: 1944-03-02
•
Granted: 1948-04-20
•
Expires: 1964-03-02
Abstract
No abstract record available.
Inventors
- 👤 Jr Royden C Sanders
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:15
CPC Classifications
H; H03; H03K; H03K25/00; G; G01; G01R; G01R23/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2307316A
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US2262407A
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US2362503A
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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) | 1951-04-20 | 1951-10-20 | 1952-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-04-20 | 1955-10-20 | 1956-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-04-20 | 1959-10-20 | 1960-04-20 | $7700.00 | Window Closed / Lapsed |