US2790347A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microscope attachment for projecting rating chart into field of vision
Assignee: United States Steel Corp
•
Filing: 1953-08-20
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Granted: 1957-04-30
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Expires: 1973-08-20
Abstract
No abstract record available.
Inventors
- 👤 Harold S Link
- 👤 Kenneth J Stodden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:46
CPC Classifications
G; G02; G02B; G02B21/00; G02B21/36; G02B21/364
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) | 1960-04-29 | 1960-10-29 | 1961-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-04-29 | 1964-10-29 | 1965-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-04-29 | 1968-10-29 | 1969-04-30 | $7700.00 | Window Closed / Lapsed |