US2643527A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Precooling air in oxygen production
Assignee: Hydrocarbon Research Inc
•
Filing: 1948-03-26
•
Granted: 1953-06-30
•
Expires: 1968-03-26
Abstract
No abstract record available.
Inventors
- 👤 Percival C Keith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:04
CPC Classifications
F; F25; F25J; F25J5/00; F25J2210/00; F25J2210/40; Y; Y10; Y10S; Y10S62/00; Y10S62/902; Y10S62/909
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US683492A
Cited
US1724513A
Cited
US2007271A
Cited
US2128692A
Cited
US2141997A
Cited
US2423543A
Cited
US2516717A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-29 | 1956-12-29 | 1957-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-29 | 1960-12-29 | 1961-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-29 | 1964-12-29 | 1965-06-30 | $7700.00 | Window Closed / Lapsed |