Patent US3418022A successfully refreshed from Google Patents.
US3418022A
Expired / Lapsed
US
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Tunnel boring apparatus
Assignee: Cooper Industries LLC
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Filing: 1966-12-22
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Granted: 1968-12-24
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Expires: 1986-12-22
Abstract
No abstract record available.
Inventors
- 👤 Carl R Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:44
CPC Classifications
E; E21; E21D; E21D9/00; E21D9/10; E21D9/1006
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1453620A
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US1659942A
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US2024730A
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US2029770A
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US2549420A
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US2769614A
Cited
GB852537A
Cited
SU135061A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-12-24 | 1972-06-24 | 1972-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-12-24 | 1976-06-24 | 1976-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-12-24 | 1980-06-24 | 1980-12-24 | $7700.00 | Window Closed / Lapsed |