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Patent US2297451A successfully refreshed from Google Patents.
US2297451A
Expired / Lapsed
US
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Method of selective filtering of frequency band ranges
Assignee: Individual
•
Filing: 1940-05-04
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Granted: 1942-09-29
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Expires: 1960-05-04
Abstract
No abstract record available.
Inventors
- 👤 Bendel Hermann
- 👤 Krambeer Karl-Heinrich
- 👤 Jacoby Hans
- 👤 Osthavelland Kreis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:23
CPC Classifications
H; H03; H03H; H03H19/00; H04; H04J; H04J1/00; H04J1/02; H04J1/04; H04J1/045
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) | 1945-09-28 | 1946-03-30 | 1946-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-09-28 | 1950-03-30 | 1950-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-09-28 | 1954-03-30 | 1954-09-29 | $7700.00 | Window Closed / Lapsed |