US3509728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low temperature separation of gases utilizing two distillation columns having a common condenser-evaporator
Assignee: Costain Petrocarbon Ltd
•
Filing: 1967-02-20
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Granted: 1970-05-05
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Expires: 1987-02-20
Abstract
No abstract record available.
Inventors
- 👤 Stanley Mercer
- 👤 Alan Alfred Haslam
- 👤 Paul L Charlesworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:40
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/0204; F25J3/0223; F25J3/0219; F25J3/0228; F25J3/0233; F25J3/0257; F25J3/0261; F25J3/028; F25J3/0285; F25J2200/00; F25J2200/04; F25J2200/06; F25J2200/40; F25J2200/50; F25J2200/72; F25J2200/74; F25J2200/76; F25J2210/00; F25J2210/12; F25J2215/00; F25J2215/04; F25J2270/00; F25J2270/04; F25J2270/08; F25J2270/12; F25J2270/14; F25J2270/24; F25J2270/88
Claims Analysis
Total Claims: 0
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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) | 1973-05-04 | 1973-11-03 | 1974-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-05-04 | 1977-11-03 | 1978-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-05-04 | 1981-11-03 | 1982-05-05 | $7700.00 | Window Closed / Lapsed |