US2777041A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High frequency heat treating apparatus
Assignee: Lindberg Engineering Co
•
Filing: 1953-05-21
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Granted: 1957-01-08
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Expires: 1973-05-21
Abstract
No abstract record available.
Inventors
- 👤 Herman C Dustman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:15
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/36; H05B6/365
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2167798A
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US2226871A
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US2493950A
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US2493771A
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GB635421A
Cited
US2623081A
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FR980873A
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US2671846A
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US2628104A
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US2654019A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-01-08 | 1960-07-09 | 1961-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-01-08 | 1964-07-09 | 1965-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-01-08 | 1968-07-09 | 1969-01-08 | $7700.00 | Window Closed / Lapsed |