US2439740A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arc welding apparatus
Assignee: Dravo Corp
•
Filing: 1943-12-29
•
Granted: 1948-04-13
•
Expires: 1963-12-29
Abstract
No abstract record available.
Inventors
- 👤 Wallace C Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:06
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/14; B23K9/142; B23K9/147
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1305039A
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US949151A
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GB112353A
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US1498167A
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US1827245A
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US1560699A
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US1884826A
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US1965331A
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US2163439A
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US2314917A
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US2357376A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-04-13 | 1951-10-13 | 1952-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-04-13 | 1955-10-13 | 1956-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-04-13 | 1959-10-13 | 1960-04-13 | $7700.00 | Window Closed / Lapsed |