Patent US3549091A successfully refreshed from Google Patents.
US2735656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rock drilling bit
Assignee: —
•
Filing: —
•
Granted: 1956-02-21
•
Expires: 1973-02-21
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:47
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46; E21B10/58
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1718462A
Cited
US1901643A
Cited
GB423647A
Cited
US2306598A
Cited
FR951335A
Cited
US2494188A
Cited
US2507221A
Cited
US2579268A
Cited
GB669636A
Cited
US2502128A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-02-20 | 1959-08-22 | 1960-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-02-20 | 1963-08-22 | 1964-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-02-20 | 1967-08-22 | 1968-02-21 | $7700.00 | Window Closed / Lapsed |