US2476580A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Educational device
Assignee: Individual
•
Filing: 1944-09-21
•
Granted: 1949-07-19
•
Expires: 1964-09-21
Abstract
No abstract record available.
Inventors
- 👤 Bergman Jack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:48
CPC Classifications
G; G09; G09B; G09B19/00; G09B19/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE420775C
Cited
US198934A
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US209416A
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US238122A
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US296900A
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US412489A
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US69482A
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DE450877C
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US845276A
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US924406A
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US1052460A
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US1159133A
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US1256224A
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FR502263A
Cited
US1536119A
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GB246174A
Cited
US1581390A
Cited
US2152777A
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US2342325A
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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) | 1952-07-18 | 1953-01-17 | 1953-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-07-18 | 1957-01-17 | 1957-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-07-18 | 1961-01-17 | 1961-07-19 | $7700.00 | Window Closed / Lapsed |