US2442790A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for identifying cross wires in optical instrument reticules by the use of polarized light
Assignee: United States Department of the Interior
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Filing: 1945-08-13
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Granted: 1948-06-08
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Expires: 1965-08-13
Abstract
No abstract record available.
Inventors
- 👤 Warner Ernest Ray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:10
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/32; Y; Y10; Y10T; Y10T29/00; Y10T29/53; Y10T29/53022
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) | 1951-06-08 | 1951-12-08 | 1952-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-06-08 | 1955-12-08 | 1956-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-06-08 | 1959-12-08 | 1960-06-08 | $7700.00 | Window Closed / Lapsed |