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US2821652A
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Multihelix traveling wave tubes
Assignee: AT&T Inc
•
Filing: 1952-10-06
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Granted: 1958-01-28
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Expires: 1972-10-06
Abstract
No abstract record available.
Inventors
- 👤 George H Robertson
- 👤 Edward J Walsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:10
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/16; H01J23/24; H01J23/26; H01J25/00; H01J25/34; H01J25/36; H01J25/38
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2578434A
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US2584308A
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US2623193A
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US2584597A
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US2730647A
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US2585582A
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US2611832A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-27 | 1961-07-29 | 1962-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-27 | 1965-07-29 | 1966-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-27 | 1969-07-29 | 1970-01-28 | $7700.00 | Window Closed / Lapsed |