US2768430A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing hollow rock drill steel
Assignee: Hellefors Bruks AB
•
Filing: 1953-10-08
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Granted: 1956-10-30
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Expires: 1973-10-08
Abstract
No abstract record available.
Inventors
- 👤 Foogde Carl Erik
- 👤 Eriksson Dan Ingemar Bernhard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:11
CPC Classifications
B; B21; B21K; B21K5/00; B21K5/02; B21K5/10; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4981; Y10T29/49826; Y10T29/49908; Y10T29/49925; Y10T29/49934; Y10T29/49938; Y10T29/4994
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2021945A
Cited
GB150562A
Cited
US1574551A
Cited
US1763651A
Cited
GB325169A
Cited
US2300353A
Cited
US2432819A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-10-30 | 1960-04-30 | 1960-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-10-30 | 1964-04-30 | 1964-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-10-30 | 1968-04-30 | 1968-10-30 | $7700.00 | Window Closed / Lapsed |