US2529574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct fired hot-air heating apparatus
Assignee: Dravo Corp
•
Filing: 1945-09-04
•
Granted: 1950-11-14
•
Expires: 1965-09-04
Abstract
No abstract record available.
Inventors
- 👤 Ralph M Rush
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:54
CPC Classifications
F; F24; F24H; F24H3/00; F24H3/02; F24H3/06; F24H3/08; F24H3/087
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US96328A
Cited
US1440465A
Cited
US1644180A
Cited
US1707531A
Cited
US1737732A
Cited
FR730002A
Cited
US2021605A
Cited
US2136235A
Cited
US2376140A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-11-13 | 1954-05-15 | 1954-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-11-13 | 1958-05-15 | 1958-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-11-13 | 1962-05-15 | 1962-11-14 | $7700.00 | Window Closed / Lapsed |