US2638889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat-treating element for heattreating furnaces
Assignee: Individual
•
Filing: 1947-05-08
•
Granted: 1953-05-19
•
Expires: 1967-05-08
Abstract
No abstract record available.
Inventors
- 👤 Doris B Dow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:22
CPC Classifications
C; C21; C21D; C21D9/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US941618A
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US1421939A
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US2146410A
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US2081612A
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US2188133A
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US2230221A
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US2400653A
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US2410881A
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US2411324A
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US2431753A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-05-18 | 1956-11-17 | 1957-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-18 | 1960-11-17 | 1961-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-18 | 1964-11-17 | 1965-05-19 | $7700.00 | Window Closed / Lapsed |