US2297539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous ceramic articles and method of making the same
Assignee: Electro Refractories & Alloys
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Filing: 1938-05-31
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Granted: 1942-09-29
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Expires: 1958-05-31
Abstract
No abstract record available.
Inventors
- 👤 Grant S Diamond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:40
CPC Classifications
C; C04; C04B; C04B38/00; C04B38/0038; B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/2072; B01D39/2075
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) | 1945-09-28 | 1946-03-30 | 1946-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-09-28 | 1950-03-30 | 1950-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-09-28 | 1954-03-30 | 1954-09-29 | $7700.00 | Window Closed / Lapsed |