US1789401A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air heater
Assignee: Babcock and Wilcox Co
•
Filing: 1930-03-07
•
Granted: 1931-01-20
•
Expires: 1950-03-07
Abstract
No abstract record available.
Inventors
- 👤 Davy Christopher Samuel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:46
CPC Classifications
F; F23; F23M; F23M20/00; Y; Y10; Y10S; Y10S122/00; Y10S122/01
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) | 1934-01-19 | 1934-07-21 | 1935-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1938-01-19 | 1938-07-21 | 1939-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1942-01-19 | 1942-07-21 | 1943-01-20 | $7700.00 | Window Closed / Lapsed |