US2671440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air heating furnace simulating a fireplace
Assignee: Individual
•
Filing: 1950-04-26
•
Granted: 1954-03-09
•
Expires: 1970-04-26
Abstract
No abstract record available.
Inventors
- 👤 Raymond R Dupler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:37
CPC Classifications
F; F24; F24B; F24B1/00; F24B1/18; F24B1/1808; F24C; F24C3/00; F24C3/002; F24C3/006
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1383506A
Cited
US1444163A
Cited
US1568816A
Cited
US1571741A
Cited
GB257202A
Cited
US1991513A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-03-08 | 1957-09-07 | 1958-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-03-08 | 1961-09-07 | 1962-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-03-08 | 1965-09-07 | 1966-03-09 | $7700.00 | Window Closed / Lapsed |