US2354742A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of producing alkali-metal sulphides, selenides, and tellurides
Assignee: MATHLESON ALKALI WORKS Inc
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Filing: 1940-04-25
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Granted: 1944-08-01
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Expires: 1960-04-25
Abstract
No abstract record available.
Inventors
- 👤 Cunningham George Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:51
CPC Classifications
C; C01; C01B; C01B19/00; C01B19/007; C01B17/00; C01B17/22; C01B17/30
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) | 1947-08-01 | 1948-01-31 | 1948-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1951-08-01 | 1952-01-31 | 1952-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1955-08-01 | 1956-01-31 | 1956-08-01 | $7700.00 | Window Closed / Lapsed |