US2849220A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Industrial furnace with removable combustion tubes
Assignee: Lindberg Engineering Co
•
Filing: 1953-09-28
•
Granted: 1958-08-26
•
Expires: 1973-09-28
Abstract
No abstract record available.
Inventors
- 👤 John R Duffy
- 👤 Lillienberg August Wilford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:58
CPC Classifications
C; C21; C21D; C21D9/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE497912C
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US1734870A
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US1991788A
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US2086970A
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US2115769A
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US2253920A
Cited
GB576853A
Cited
US2472497A
Cited
US2485995A
Cited
GB675276A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-08-25 | 1962-02-24 | 1962-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-08-25 | 1966-02-24 | 1966-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-08-25 | 1970-02-24 | 1970-08-26 | $7700.00 | Window Closed / Lapsed |