US3444696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Demethanization employing different temperature level refrigerants
Assignee: Stone and Webster Engineering Corp
•
Filing: 1967-02-10
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Granted: 1969-05-20
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Expires: 1987-02-10
Abstract
No abstract record available.
Inventors
- 👤 Ray L Geddes
- 👤 John K Jacobs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:17
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/04; F; F25; F25J; F25J3/00; F25J3/02; F25J3/0204; F25J3/0219; F25J3/0228; F25J3/0233; F25J3/0238; F25J2200/00; F25J2200/50; F25J2210/00; F25J2210/12; F25J2235/00; F25J2235/60; F25J2245/00; F25J2245/02; F25J2270/00; F25J2270/12; F25J2270/60; F25J2290/00; F25J2290/40
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2214790A
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US2471602A
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US2777305A
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US2880592A
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US2953905A
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US3262278A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-05-19 | 1972-11-18 | 1973-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-05-19 | 1976-11-18 | 1977-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-05-19 | 1980-11-18 | 1981-05-20 | $7700.00 | Window Closed / Lapsed |