Patent US2644020A successfully refreshed from Google Patents.
US2644020A
Expired / Lapsed
US
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Graphitization of carbon articles
Assignee: Union Carbide Corp
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Filing: 1950-03-28
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Granted: 1953-06-30
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Expires: 1970-03-28
Abstract
No abstract record available.
Inventors
- 👤 Hamister Victor Carl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:38
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/528; C04B35/532; C01; C01B; C01B32/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US752357A
Cited
US865608A
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US840044A
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US1030620A
Cited
US1130215A
Cited
US1440724A
Cited
US1390823A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-29 | 1956-12-29 | 1957-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-29 | 1960-12-29 | 1961-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-29 | 1964-12-29 | 1965-06-30 | $7700.00 | Window Closed / Lapsed |