US2600020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Forced air flow air-heating furnace
Assignee: Dravo Corp
•
Filing: 1948-11-26
•
Granted: 1952-06-10
•
Expires: 1968-11-26
Abstract
No abstract record available.
Inventors
- 👤 Herman A Pietsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:32
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)
US563240A
Cited
US764191A
Cited
US901829A
Cited
US1519673A
Cited
US1545710A
Cited
US2451851A
Cited
US2431772A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-06-10 | 1955-12-10 | 1956-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-06-10 | 1959-12-10 | 1960-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-06-10 | 1963-12-10 | 1964-06-10 | $7700.00 | Window Closed / Lapsed |