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US3455116A
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Helium purification employing propane scrubbing
Assignee: University of Kansas Endowment Association (KU Endowment)
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Filing: 1967-01-03
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Granted: 1969-07-15
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Expires: 1987-01-03
Abstract
No abstract record available.
Inventors
- 👤 George W Swift
- 👤 Fred Kurata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:11
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/0228; F25J3/028; F25J3/029; F25J3/08; F25J2205/00; F25J2205/30; F25J2205/50; F25J2215/00; F25J2215/30
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-07-14 | 1973-01-13 | 1973-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-07-14 | 1977-01-13 | 1977-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-07-14 | 1981-01-13 | 1981-07-15 | $7700.00 | Window Closed / Lapsed |