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Patent US3489492A successfully refreshed from Google Patents.
US3489492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film projector for educational apparatus
Assignee: PALISADES EDUCATIONAL FOUNDATION Inc
•
Filing: 1966-12-19
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Granted: 1970-01-13
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Expires: 1986-12-19
Abstract
No abstract record available.
Inventors
- 👤 Richard Kobler
- 👤 Bruce N Whitlock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:43
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/14; G03B21/32; G03B21/50
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1802045A
Cited
US1944029A
Cited
US2173230A
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US2413288A
Cited
US3152741A
Cited
US3301628A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-01-12 | 1973-07-14 | 1974-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-01-12 | 1977-07-14 | 1978-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-01-12 | 1981-07-14 | 1982-01-13 | $7700.00 | Window Closed / Lapsed |