US2395524A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing porous silica
Assignee: Houdry Process Corp
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Filing: 1941-07-22
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Granted: 1946-02-26
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Expires: 1961-07-22
Abstract
No abstract record available.
Inventors
- 👤 Harry B Weiser
- 👤 Winfred O Milligan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:51
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/152; C01B33/154; B; B01; B01J; B01J21/00; B01J21/06; B01J21/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1949-02-25 | 1949-08-27 | 1950-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1953-02-25 | 1953-08-27 | 1954-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1957-02-25 | 1957-08-27 | 1958-02-26 | $7700.00 | Window Closed / Lapsed |