US2932173A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of liquefying helium
Assignee: Beechcraft Corp
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Filing: 1957-12-13
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Granted: 1960-04-12
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Expires: 1977-12-13
Abstract
No abstract record available.
Inventors
- 👤 Gerald D Mordhorst
- 👤 Kenneth R Leonard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:18
CPC Classifications
F; F25; F25J; F25J1/00; F25J1/02; F25J1/0243; F25J1/0257; F25J1/0262; F25J1/0264; F25J1/0002; F25J1/0005; F25J1/0007; F25J1/003; F25J1/0032; F25J1/0035; F25J1/0037; F25J1/004; F25J1/0221; F25J1/0224; F25J2210/00; F25J2210/42; F25J2210/50; F25J2250/00; F25J2250/02; 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) | 1963-04-12 | 1963-10-12 | 1964-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-04-12 | 1967-10-12 | 1968-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-04-12 | 1971-10-12 | 1972-04-12 | $7700.00 | Window Closed / Lapsed |