Patent US6422897B1 successfully refreshed from Google Patents.
US3225070A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polycyclic compounds
Assignee: Shell USA Inc
•
Filing: 1961-12-28
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Granted: 1965-12-21
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Expires: 1981-12-28
Abstract
No abstract record available.
Inventors
- 👤 Fan Hsing Yun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:25
CPC Classifications
C; C07; C07D; C07D303/00; C07D303/02; C07D303/12; C07D303/32
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
5 words
THE COMPOUND OF THE FORMULA:
Claim 2
Dependent Claim
5 words
THE COMPOUND OF THE FORMULA:
References Cited (Backward Citations)
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Cited
US2745848A
Cited
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-12-20 | 1969-06-21 | 1969-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-20 | 1973-06-21 | 1973-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-20 | 1977-06-21 | 1977-12-21 | $7700.00 | Window Closed / Lapsed |