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Patent US1984342A successfully refreshed from Google Patents.
US1984342A
Expired / Lapsed
US
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Purification of sodium carbonate
Assignee: West End Chemical Co
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Filing: 1933-05-17
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Granted: 1934-12-11
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Expires: 1953-05-17
Abstract
No abstract record available.
Inventors
- 👤 Henry D Hellmers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:29
CPC Classifications
C; C01; C01D; C01D7/00; C01D7/22; C01D7/30
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) | 1937-12-10 | 1938-06-11 | 1938-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1941-12-10 | 1942-06-11 | 1942-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1945-12-10 | 1946-06-11 | 1946-12-11 | $7700.00 | Window Closed / Lapsed |