Patent US2274671A successfully refreshed from Google Patents.
US2274671A
Expired / Lapsed
US
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Formation of chromium-containing layers on ferrous surfaces
Assignee: Individual
•
Filing: 1939-10-31
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Granted: 1942-03-03
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Expires: 1959-10-31
Abstract
No abstract record available.
Inventors
- 👤 Daeves Karl
- 👤 Becker Gottfried
- 👤 Steinberg Fritz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:48
CPC Classifications
C; C23; C23C; C23C10/00; C23C10/06; C23C10/08; C23C10/10; C23C10/28; C23C10/34; C23C10/36; C23C10/38; C23C10/40; C23C10/42
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1945-03-02 | 1945-09-01 | 1946-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-03-02 | 1949-09-01 | 1950-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-03-02 | 1953-09-01 | 1954-03-03 | $7700.00 | Window Closed / Lapsed |