US2841297A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and apparatus for constructing tunnels
Assignee: American Marietta Co
•
Filing: 1954-09-13
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Granted: 1958-07-01
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Expires: 1974-09-13
Abstract
No abstract record available.
Inventors
- 👤 Edward P Washabaugh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:55
CPC Classifications
E; E21; E21D; E21D11/00; E21D11/14; E21D11/18; E21D11/40
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US168146A
Cited
US1766568A
Cited
US1819426A
Cited
US1979896A
Cited
US2067711A
Cited
US2429045A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-30 | 1961-12-30 | 1962-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-30 | 1965-12-30 | 1966-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-30 | 1969-12-30 | 1970-07-01 | $7700.00 | Window Closed / Lapsed |