Patent US3521428A successfully refreshed from Google Patents.
US3521428A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase separation
Assignee: Phillips Petroleum Co
•
Filing: 1968-06-20
•
Granted: 1970-07-21
•
Expires: 1988-06-20
Abstract
No abstract record available.
Inventors
- 👤 Robert E Dollinger
- 👤 Robert H Kallenberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:23
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/44; C09C1/48; C09C1/487; C01; C01P; C01P2004/00; C01P2004/51
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
CA707684A
Cited
US1617071A
Cited
US1601148A
Cited
US1784278A
Cited
US2500851A
Cited
US2805732A
Cited
US2861649A
Cited
US2966232A
Cited
US3146080A
Cited
US3318070A
Cited
US3384460A
Cited
US3411929A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-20 | 1974-01-19 | 1974-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-20 | 1978-01-19 | 1978-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-20 | 1982-01-19 | 1982-07-21 | $7700.00 | Window Closed / Lapsed |