US2018926A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for excavating tunnels
Assignee: Individual
•
Filing: 1934-04-23
•
Granted: 1935-10-29
•
Expires: 1954-04-23
Abstract
No abstract record available.
Inventors
- 👤 George J Schroepfer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:51
CPC Classifications
E; E21; E21D; E21D9/00; E21D9/10; E21D9/1066; B; B26; B26F; B26F3/00; B26F3/004
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1938-10-28 | 1939-04-29 | 1939-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-10-28 | 1943-04-29 | 1943-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-10-28 | 1947-04-29 | 1947-10-29 | $7700.00 | Window Closed / Lapsed |