US2812499A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helix assembly for traveling wave tube
Assignee: AT&T Inc
•
Filing: 1952-07-11
•
Granted: 1957-11-05
•
Expires: 1972-07-11
Abstract
No abstract record available.
Inventors
- 👤 George H Robertson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:33
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/16; H01J23/24; H01J23/26; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49016
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2174853A
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US2277150A
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FR984959A
Cited
US2602148A
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US2541843A
Cited
US2549551A
Cited
US2567415A
Cited
US2611102A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-11-04 | 1961-05-06 | 1961-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-11-04 | 1965-05-06 | 1965-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-11-04 | 1969-05-06 | 1969-11-05 | $7700.00 | Window Closed / Lapsed |