US2798408A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vision testing devices
Assignee: American Optical Corp
•
Filing: 1953-03-09
•
Granted: 1957-07-09
•
Expires: 1973-03-09
Abstract
No abstract record available.
Inventors
- 👤 Charles A Ellis
- 👤 Henry B Cole
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:29
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/02; A61B3/028; A61B3/032; A61B3/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US726101A
Cited
US760458A
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US2033529A
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US2095235A
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US2147957A
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US2364793A
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US2481582A
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US2485272A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-07-08 | 1961-01-07 | 1961-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-07-08 | 1965-01-07 | 1965-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-07-08 | 1969-01-07 | 1969-07-09 | $7700.00 | Window Closed / Lapsed |