Patent US2977689A successfully refreshed from Google Patents.
US2977689A
Expired / Lapsed
US
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Multiple choice response device
Assignee: Individual
•
Filing: 1958-10-30
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Granted: 1961-04-04
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Expires: 1978-10-30
Abstract
No abstract record available.
Inventors
- 👤 Gerhard T Rugland
- 👤 John P Yackel
- 👤 Arthur P Bergee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:28
CPC Classifications
G; G09; G09B; G09B3/00; G09B3/06; G09B3/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-04-03 | 1964-10-03 | 1965-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-03 | 1968-10-03 | 1969-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-03 | 1972-10-03 | 1973-04-04 | $7700.00 | Window Closed / Lapsed |