US3447331A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air separation employing waste nitrogen reheated by incoming air in work expansion
Assignee: BOC Group Ltd
•
Filing: 1967-05-09
•
Granted: 1969-06-03
•
Expires: 1987-05-09
Abstract
No abstract record available.
Inventors
- 👤 Kenneth C Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:42
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04406; F25J3/04412; F25J3/04248; F25J3/04284; F25J3/04309; F25J3/04315; F25J3/04642; F25J3/04648; F25J3/04654; F25J3/04666; F25J3/04672; F25J3/04678; F25J5/00; F25J2200/00; F25J2200/20; F25J2250/00; F25J2250/02
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2502250A
Cited
US2918802A
Cited
US3070966A
Cited
US3261168A
Cited
US3216206A
Cited
US3217502A
Cited
US3327488A
Cited
US3340697A
Cited
US3375673A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-06-02 | 1972-12-02 | 1973-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-02 | 1976-12-02 | 1977-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-02 | 1980-12-02 | 1981-06-03 | $7700.00 | Window Closed / Lapsed |