US2658729A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preheater-type heat exchanger
Assignee: Individual
•
Filing: 1949-06-01
•
Granted: 1953-11-10
•
Expires: 1969-06-01
Abstract
No abstract record available.
Inventors
- 👤 Horwitz Saul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:25
CPC Classifications
F; F23; F23K; F23K5/00; F23K5/02; F23K5/14; F23K5/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
FR319221A
Cited
US979618A
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US1209836A
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AT105059B
Cited
US1807538A
Cited
US1738455A
Cited
FR719848A
Cited
DE555313C
Cited
US2303613A
Cited
US2466525A
Cited
US2457022A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-11-09 | 1957-05-11 | 1957-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-11-09 | 1961-05-11 | 1961-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-11-09 | 1965-05-11 | 1965-11-10 | $7700.00 | Window Closed / Lapsed |