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US2763469A
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US
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Rotary rock drills
Assignee: Cementation Co Ltd
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Filing: 1952-12-30
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Granted: 1956-09-18
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Expires: 1972-12-30
Abstract
No abstract record available.
Inventors
- 👤 Burls John Albert Edward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:35
CPC Classifications
E; E21; E21B; E21B4/00; E21B4/06; E21B4/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1778966A
Cited
US1854623A
Cited
US1845074A
Cited
US1901513A
Cited
US2072470A
Cited
US2153883A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-09-18 | 1960-03-19 | 1960-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-09-18 | 1964-03-19 | 1964-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-09-18 | 1968-03-19 | 1968-09-18 | $7700.00 | Window Closed / Lapsed |