Patent US2531454A successfully refreshed from Google Patents.
US2531454A
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US
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Directive antenna structure
Assignee: Unisys Corp
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Filing: 1942-02-04
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Granted: 1950-11-28
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Expires: 1962-02-04
Abstract
No abstract record available.
Inventors
- 👤 Robert J Marshall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:17
CPC Classifications
H; H01; H01Q; H01Q3/00; H01Q3/12; H01Q3/16; H01Q3/18; H01Q19/00; H01Q19/10; H01Q19/18; H01Q19/19; H01Q19/193
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) | 1953-11-27 | 1954-05-29 | 1954-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-11-27 | 1958-05-29 | 1958-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-11-27 | 1962-05-29 | 1962-11-28 | $7700.00 | Window Closed / Lapsed |