US3407884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-way ground burrowing device
Assignee: Individual
•
Filing: 1967-04-11
•
Granted: 1968-10-29
•
Expires: 1987-04-11
Abstract
No abstract record available.
Inventors
- 👤 Zygmunt Kazimierz
- 👤 Gerlach Tadeusz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:20
CPC Classifications
E; E21; E21B; E21B4/00; E21B4/06; E21B4/14; E21B4/145
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) | 1971-10-29 | 1972-04-29 | 1972-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-10-29 | 1976-04-29 | 1976-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-10-29 | 1980-04-29 | 1980-10-29 | $7700.00 | Window Closed / Lapsed |