US3405457A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Versatile display teaching system
Assignee: University of Illinois at Urbana-Champaign
•
Filing: 1965-10-23
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Granted: 1968-10-15
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Expires: 1985-10-23
Abstract
No abstract record available.
Inventors
- 👤 Donald L Bitzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:29
CPC Classifications
G; G09; G09B; G09B7/00; G09B7/06; G09B7/07; G09B7/077
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US3075178A
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US3063036A
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US3103073A
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US3121959A
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US3141243A
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US3248705A
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US3195403A
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US3256516A
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US3278677A
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US3273260A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-10-15 | 1972-04-15 | 1972-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-10-15 | 1976-04-15 | 1976-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-10-15 | 1980-04-15 | 1980-10-15 | $7700.00 | Window Closed / Lapsed |