US3159571A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Residual oil refining process
Assignee: Shell USA Inc
•
Filing: 1961-11-22
•
Granted: 1964-12-01
•
Expires: 1981-11-22
Abstract
No abstract record available.
Inventors
- 👤 Gerrit H Reman
- 👤 Groothuis Hendrik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:30
CPC Classifications
C; C10; C10G; C10G53/00; C10G53/02; C10G53/04
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-12-01 | 1968-06-01 | 1968-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-12-01 | 1972-06-01 | 1972-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-12-01 | 1976-06-01 | 1976-12-01 | $7700.00 | Window Closed / Lapsed |