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US2839271A
Expired / Lapsed
US
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Tunneling machine
Assignee: Individual
•
Filing: 1955-05-02
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Granted: 1958-06-17
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Expires: 1975-05-02
Abstract
No abstract record available.
Inventors
- 👤 Charles W Kandle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:58
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/003; E21B7/005; E21B7/28
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-16 | 1961-12-16 | 1962-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-16 | 1965-12-16 | 1966-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-16 | 1969-12-16 | 1970-06-17 | $7700.00 | Window Closed / Lapsed |