US3516261A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas mixture separation by distillation with feed-column heat exchange and intermediate plural stage work expansion of the feed
Assignee: McDonnell Douglas Corp
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Filing: 1969-04-21
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Granted: 1970-06-23
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Expires: 1989-04-21
Abstract
No abstract record available.
Inventors
- 👤 Michael L Hoffman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:20
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/0228; F25J3/0238; F25J3/0204; F25J3/0209; F25J3/0233; F25J2200/00; F25J2200/02; F25J2200/50; F25J2200/70; F25J2200/80; F25J2205/00; F25J2205/02; F25J2205/04; F25J2240/00; F25J2240/02; F25J2270/00; F25J2270/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1460545A
Cited
US2503265A
Cited
US2661608A
Cited
US2675883A
Cited
US2713780A
Cited
US3280060A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-06-22 | 1973-12-22 | 1974-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-06-22 | 1977-12-22 | 1978-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-06-22 | 1981-12-22 | 1982-06-23 | $7700.00 | Window Closed / Lapsed |