US3521457A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for making hydrogen slush using nitrogen and helium refrigerants
Assignee: Airco Inc
•
Filing: 1967-07-19
•
Granted: 1970-07-21
•
Expires: 1987-07-19
Abstract
No abstract record available.
Inventors
- 👤 Russell A Hemstreet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:58
CPC Classifications
F; F25; F25J; F25J1/00; F25J1/0002; F25J1/0005; F25J1/001; F25J1/003; F25J1/0047; F25J1/0052; F25J1/006; F25J1/0062; F25J1/0065; F25J1/007; F25J1/0072; F25J1/02; F25J1/0203; F25J1/0205; F25J1/0221; F25J1/0243; F25J1/0257; F25J1/0275; F25J1/0276; F25J2205/00; F25J2205/20; F25J2210/00; F25J2210/42; F25J2250/00; F25J2250/02; F25J2290/00; F25J2290/42
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2512040A
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US2895303A
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US2902839A
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US2909903A
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US3116427A
Cited
US3235002A
Cited
US3354662A
Cited
US3230737A
Cited
US3319436A
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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) | 1973-07-20 | 1974-01-19 | 1974-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-20 | 1978-01-19 | 1978-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-20 | 1982-01-19 | 1982-07-21 | $7700.00 | Window Closed / Lapsed |