Patent US1920307A successfully refreshed from Google Patents.
US1920307A
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US
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Method and apparatus for the liberation or concentration of acids by heating under reduced pressure
Assignee: Chemical Construction Corp
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Filing: 1931-07-24
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Granted: 1933-08-01
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Expires: 1951-07-24
Abstract
No abstract record available.
Inventors
- 👤 Hechenbleikner Ingenuin
- 👤 Titlestad Nicolay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:06
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/20; C01B21/38; C01B21/44; Y; Y10; Y10S; Y10S159/00; Y10S159/19
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) | 1936-07-31 | 1937-01-30 | 1937-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1940-07-31 | 1941-01-30 | 1941-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1944-07-31 | 1945-01-30 | 1945-08-01 | $7700.00 | Window Closed / Lapsed |