Patent US2987832A successfully refreshed from Google Patents.
US2987832A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blackboard setting system
Assignee: Individual
•
Filing: 1957-04-29
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Granted: 1961-06-13
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Expires: 1977-04-29
Abstract
No abstract record available.
Inventors
- 👤 Leon F Urbain
- 👤 Matthew P Glowacki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:12
CPC Classifications
B; B43; B43L; B43L1/00; B43L1/04; B43L1/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US892259A
Cited
US1880179A
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US2066824A
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US2336604A
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US2463110A
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US2683506A
Cited
US2744714A
Cited
FR1060052A
Cited
US2696962A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-06-12 | 1964-12-12 | 1965-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-12 | 1968-12-12 | 1969-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-12 | 1972-12-12 | 1973-06-13 | $7700.00 | Window Closed / Lapsed |