US2579268A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rock drill bit having hard inserts forming cutting edges
Assignee: Individual
•
Filing: 1947-08-28
•
Granted: 1951-12-18
•
Expires: 1967-08-28
Abstract
No abstract record available.
Inventors
- 👤 Malherbe Johannes Andrea Smuts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:41
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46; E21B10/58; E21B10/56
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US652554A
Cited
GB190611646A
Cited
US1969040A
Cited
US2065898A
Cited
US2101376A
Cited
GB500147A
Cited
US2203216A
Cited
US2215948A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-12-17 | 1955-06-18 | 1955-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-12-17 | 1959-06-18 | 1959-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-12-17 | 1963-06-18 | 1963-12-18 | $7700.00 | Window Closed / Lapsed |