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US2201958A
Expired / Lapsed
US
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Preheating ammonia-air mixtures
Assignee: Chemical Construction Corp
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Filing: 1937-12-04
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Granted: 1940-05-21
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Expires: 1957-12-04
Abstract
No abstract record available.
Inventors
- 👤 Ralph S Richardson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:18
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/20; C01B21/24; C01B21/26; Y; Y02; Y02P; Y02P20/00; Y02P20/10; Y02P20/129
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) | 1943-05-21 | 1943-11-20 | 1944-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-05-21 | 1947-11-20 | 1948-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-05-21 | 1951-11-20 | 1952-05-21 | $7700.00 | Window Closed / Lapsed |