US3389565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for liquefaction of helium by expansion
Assignee: Sulzer AG
•
Filing: 1965-04-21
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Granted: 1968-06-25
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Expires: 1985-04-21
Abstract
No abstract record available.
Inventors
- 👤 Ergenc Sahabettin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:49
CPC Classifications
F; F25; F25J; F25J1/00; F25J1/02; F25J1/0221; F25J1/0224; F25J1/0002; F25J1/0005; F25J1/0007; F25J1/003; F25J1/0032; F25J1/0035; F25J1/0037; F25J1/004; F25J1/0045; F25J1/0201; F25J1/0202; F25J2210/00; F25J2210/42; F25J2270/00; F25J2270/04; F25J2270/06
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) | 1971-06-25 | 1971-12-25 | 1972-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-06-25 | 1975-12-25 | 1976-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-06-25 | 1979-12-25 | 1980-06-25 | $7700.00 | Window Closed / Lapsed |