Patent US2433681A successfully refreshed from Google Patents.
US2433681A
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Radio reflection direction and distance determining system
Assignee: EMI Ltd
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Filing: 1942-06-13
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Granted: 1947-12-30
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Expires: 1962-06-13
Abstract
No abstract record available.
Inventors
- 👤 Blumlein Alan Dower
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:50
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/26; G; G01; G01S; G01S1/00; G01S1/02; G01S13/00; G01S13/02; G01S13/50; G01S13/52; G01S7/00; G01S7/02; G01S7/28; G01S7/285; G01S7/288; G06; G06G; G06G7/00; G06G7/12; G06G7/24
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) | 1950-12-29 | 1951-06-30 | 1951-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-12-29 | 1955-06-30 | 1955-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-12-29 | 1959-06-30 | 1959-12-30 | $7700.00 | Window Closed / Lapsed |