US2439503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air-heating device for fireplaces
Assignee: Individual
•
Filing: 1943-11-12
•
Granted: 1948-04-13
•
Expires: 1963-11-12
Abstract
No abstract record available.
Inventors
- 👤 Albert B Austin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:20
CPC Classifications
F; F24; F24B; F24B1/00; F24B1/18; F24B1/185; F24B1/188; F24B1/1885
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US525208A
Cited
FR750582A
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US1208974A
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US1539591A
Cited
US1646307A
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US1552236A
Cited
US1656326A
Cited
US1670034A
Cited
US1631696A
Cited
US1718859A
Cited
GB347021A
Cited
GB497968A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-04-13 | 1951-10-13 | 1952-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-04-13 | 1955-10-13 | 1956-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-04-13 | 1959-10-13 | 1960-04-13 | $7700.00 | Window Closed / Lapsed |