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US2444158A
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Thermionic device and getter elements therefor
Assignee: Fansteel Inc
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Filing: 1944-07-31
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Granted: 1948-06-29
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Expires: 1964-07-31
Abstract
No abstract record available.
Inventors
- 👤 Frank H Driggs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:06
CPC Classifications
H; H01; H01J; H01J7/00; H01J7/14; H01J7/18; H01J7/183
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-06-29 | 1951-12-29 | 1952-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-06-29 | 1955-12-29 | 1956-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-06-29 | 1959-12-29 | 1960-06-29 | $7700.00 | Window Closed / Lapsed |