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US2147756A
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Secondary electron tube
Assignee: FIRM OF FERNSEH AKTIEN GES
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Filing: 1937-02-11
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Granted: 1939-02-21
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Expires: 1957-02-11
Abstract
No abstract record available.
Inventors
- 👤 Ruska Ernst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:16
CPC Classifications
H; H01; H01J; H01J43/00; H01J43/04; H01J43/06; H01J43/18; H01J43/20
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) | 1942-02-20 | 1942-08-22 | 1943-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-02-20 | 1946-08-22 | 1947-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-02-20 | 1950-08-22 | 1951-02-21 | $7700.00 | Window Closed / Lapsed |