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Patent US1511561A successfully refreshed from Google Patents.
US1511561A
Expired / Lapsed
US
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Process of making artificial cryolite
Assignee: Grasselli Chemical Co
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Filing: 1923-06-08
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Granted: 1924-10-14
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Expires: 1943-06-08
Abstract
No abstract record available.
Inventors
- 👤 Howard Henry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:03
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/48; C01F7/50; C01F7/54
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) | 1927-10-14 | 1928-04-14 | 1928-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1931-10-14 | 1932-04-14 | 1932-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1935-10-14 | 1936-04-14 | 1936-10-14 | $7700.00 | Window Closed / Lapsed |