US3535887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High purity oxygen production from air by plural stage separation of plural streams of compressed air with utilization of recompressed overhead as a source of heat exchange
Assignee: McDonnell Douglas Corp
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Filing: 1967-12-01
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Granted: 1970-10-27
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Expires: 1987-12-01
Abstract
No abstract record available.
Inventors
- 👤 Michael L Hoffman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:20
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04248; F25J3/04284; F25J3/0429; F25J3/04303; F25J3/04006; F25J3/04048; F25J3/0406; F25J3/04624; F25J3/0463; F25J3/04642; F25J3/04648; F25J3/04654; F25J3/04709; F25J3/04715; F25J2200/00; F25J2200/08; F25J2215/00; F25J2215/40; Y; Y10; Y10S; Y10S62/00; Y10S62/923; Y10S62/924
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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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) | 1973-10-26 | 1974-04-27 | 1974-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-10-26 | 1978-04-27 | 1978-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-10-26 | 1982-04-27 | 1982-10-27 | $7700.00 | Window Closed / Lapsed |