Patent US2215891A successfully refreshed from Google Patents.
US2215891A
Expired / Lapsed
US
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Method of producing hydrated calcium silicate minerals and products thereof
Assignee: Gypsum Lime and Alabastine Canada Ltd
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Filing: 1938-11-12
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Granted: 1940-09-24
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Expires: 1958-11-12
Abstract
No abstract record available.
Inventors
- 👤 Thomson George Miller
- 👤 Erdeley Zoltan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:32
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/22; C01B33/24; C04; C04B; C04B28/00; C04B28/18
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) | 1943-09-24 | 1944-03-25 | 1944-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-09-24 | 1948-03-25 | 1948-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-09-24 | 1952-03-25 | 1952-09-24 | $7700.00 | Window Closed / Lapsed |