US2837324A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for drilling large holes between galleries
Assignee: WEST CANADIAN COLLIERIES Ltd
•
Filing: 1955-04-04
•
Granted: 1958-06-03
•
Expires: 1975-04-04
Abstract
No abstract record available.
Inventors
- 👤 Aschacker Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:51
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/28
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1728914A
Cited
US1878036A
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US1998294A
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US2633334A
Cited
US2669441A
Cited
US2684834A
Cited
BE517596A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-02 | 1961-12-02 | 1962-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-02 | 1965-12-02 | 1966-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-02 | 1969-12-02 | 1970-06-03 | $7700.00 | Window Closed / Lapsed |