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US2690621A
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Question and hidden answer device
Assignee: Individual
•
Filing: 1952-02-05
•
Granted: 1954-10-05
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Expires: 1972-02-05
Abstract
No abstract record available.
Inventors
- 👤 Ralph L Dean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:09
CPC Classifications
A; A63; A63F; A63F9/00; A63F9/18
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US724392A
Cited
US716631A
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US1121867A
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DE398626C
Cited
US1728630A
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US1749226A
Cited
US1842150A
Cited
US2157058A
Cited
US2317107A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-10-04 | 1958-04-05 | 1958-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-10-04 | 1962-04-05 | 1962-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-10-04 | 1966-04-05 | 1966-10-05 | $7700.00 | Window Closed / Lapsed |