Patent US4387092A successfully refreshed from Google Patents.
US3528501A
Expired / Lapsed
US
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Recovery of oil from oil shale
Assignee: Phillips Petroleum Co
•
Filing: 1967-08-04
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Granted: 1970-09-15
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Expires: 1987-08-04
Abstract
No abstract record available.
Inventors
- 👤 Harry W Parker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:59
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/34; E21B43/40; E21B43/16; E21B43/24
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2813583A
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US3061009A
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US3349850A
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US3284281A
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US3358756A
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US3322194A
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US3352355A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-09-14 | 1974-03-16 | 1974-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-09-14 | 1978-03-16 | 1978-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-09-14 | 1982-03-16 | 1982-09-15 | $7700.00 | Window Closed / Lapsed |