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US2999675A
Expired / Lapsed
US
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Pre-heater or furnace assembly
Assignee: Selas Corp of America
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Filing: 1953-11-13
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Granted: 1961-09-12
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Expires: 1973-11-13
Abstract
No abstract record available.
Inventors
- 👤 Jr John E Erhardt
- 👤 Elhardt M Siegel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:12
CPC Classifications
C; C21; C21D; C21D9/00; C21D9/52; C21D9/54; C21D9/56
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
GB409909A
Cited
US2210032A
Cited
US2409431A
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US2448009A
Cited
US2666003A
Cited
US2668700A
Cited
US2668701A
Cited
US2742274A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-09-11 | 1965-03-13 | 1965-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-09-11 | 1969-03-13 | 1969-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-09-11 | 1973-03-13 | 1973-09-12 | $7700.00 | Window Closed / Lapsed |