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US2420802A
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Selective-speed telegraph code instruction system
Assignee: DE FOREST'S TRAINING Inc
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Filing: 1942-11-14
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Granted: 1947-05-20
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Expires: 1962-11-14
Abstract
No abstract record available.
Inventors
- 👤 Orville I Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:57
CPC Classifications
G; G09; G09B; G09B19/00; G09B19/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1848799A
Cited
US680695A
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US1804136A
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US1962467A
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US1950011A
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US2284024A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-05-19 | 1950-11-18 | 1951-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-05-19 | 1954-11-18 | 1955-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-05-19 | 1958-11-18 | 1959-05-20 | $7700.00 | Window Closed / Lapsed |