US2837086A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Visual training device
Assignee: American Optical Corp
•
Filing: 1952-03-05
•
Granted: 1958-06-03
•
Expires: 1972-03-05
Abstract
No abstract record available.
Inventors
- 👤 Milton R Thorburn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:25
CPC Classifications
A; A61; A61H; A61H5/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1729617A
Cited
GB264615A
Cited
US2280297A
Cited
US2233689A
Cited
US2238207A
Cited
US2676588A
Cited
US2670654A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-02 | 1961-12-02 | 1962-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-02 | 1965-12-02 | 1966-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-02 | 1969-12-02 | 1970-06-03 | $7700.00 | Window Closed / Lapsed |