US3484956A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for use in the manner of using a blackboard
Assignee: Pilkington Group Ltd
•
Filing: 1966-09-14
•
Granted: 1969-12-23
•
Expires: 1986-09-14
Abstract
No abstract record available.
Inventors
- 👤 Jack Warwick Nightingale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:18
CPC Classifications
B; B43; B43L; B43L1/00; B43L1/04; B43L1/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US333483A
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US564211A
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US1790549A
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GB190720668A
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US1381022A
Cited
US1559665A
Cited
US1596457A
Cited
FR823795A
Cited
GB500443A
Cited
US2895234A
Cited
US2947093A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-12-22 | 1973-06-23 | 1973-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-12-22 | 1977-06-23 | 1977-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-12-22 | 1981-06-23 | 1981-12-23 | $7700.00 | Window Closed / Lapsed |