Patent US3468133A successfully refreshed from Google Patents.
US3468133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Excavation type shield with no rotary cutters
Assignee: Kumagai Gumi Co Ltd
•
Filing: 1967-07-19
•
Granted: 1969-09-23
•
Expires: 1987-07-19
Abstract
No abstract record available.
Inventors
- 👤 Kunijiro Matsushita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:29
CPC Classifications
E; E21; E21D; E21D9/00; E21D9/06; E21D9/08
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1866416A
Cited
US2208608A
Cited
US2425169A
Cited
CH384612A
Cited
US3372553A
Cited
US3306055A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-09-22 | 1973-03-24 | 1973-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-09-22 | 1977-03-24 | 1977-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-09-22 | 1981-03-24 | 1981-09-23 | $7700.00 | Window Closed / Lapsed |