US2199189A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Beat frequency indicator
Assignee: RCA Corp
•
Filing: 1937-03-31
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Granted: 1940-04-30
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Expires: 1957-03-31
Abstract
No abstract record available.
Inventors
- 👤 Ranald D Scheldorf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 01:20
CPC Classifications
G; G01; G01R; G01R23/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1943-04-30 | 1943-10-30 | 1944-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-04-30 | 1947-10-30 | 1948-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-04-30 | 1951-10-30 | 1952-04-30 | $7700.00 | Window Closed / Lapsed |