Patent US2809223A successfully refreshed from Google Patents.
US2809223A
Expired / Lapsed
US
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Terminal for heating furnaces
Assignee: Lindberg Engineering Co
•
Filing: 1955-09-26
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Granted: 1957-10-08
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Expires: 1975-09-26
Abstract
No abstract record available.
Inventors
- 👤 Cary H Stevenson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:01
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/62
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1350876A
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US2735881A
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US1093512A
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US1298609A
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US1367341A
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US1733530A
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US2125075A
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US2615060A
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US2694740A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-10-07 | 1961-04-08 | 1961-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-10-07 | 1965-04-08 | 1965-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-10-07 | 1969-04-08 | 1969-10-08 | $7700.00 | Window Closed / Lapsed |