Patent US2275420A successfully refreshed from Google Patents.
US2275420A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metallurgy of ferrous metals
Assignee: Individual
•
Filing: 1938-04-30
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Granted: 1942-03-10
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Expires: 1958-04-30
Abstract
No abstract record available.
Inventors
- 👤 Frances H Clark
- 👤 Robert F Dirkes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:47
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0257; C22C33/0264; C22C33/0271; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/932; Y10T; Y10T407/00; Y10T407/27
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) | 1945-03-09 | 1945-09-08 | 1946-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-03-09 | 1949-09-08 | 1950-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-03-09 | 1953-09-08 | 1954-03-10 | $7700.00 | Window Closed / Lapsed |