US2775827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for reading training
Assignee: PERCEPTUAL DEV LAB Inc
•
Filing: 1951-05-23
•
Granted: 1957-01-01
•
Expires: 1971-05-23
Abstract
No abstract record available.
Inventors
- 👤 Louis J Stoyanoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:59
CPC Classifications
G; G09; G09B; G09B17/00; G09B17/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US560425A
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US1719756A
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FR831425A
Cited
US2266798A
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US2357593A
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US2503740A
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US2512256A
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US2535243A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-01-01 | 1960-07-02 | 1961-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-01-01 | 1964-07-02 | 1965-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-01-01 | 1968-07-02 | 1969-01-01 | $7700.00 | Window Closed / Lapsed |