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US3419081A
Expired / Lapsed
US
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Well cementing device
Assignee: Koehring Co
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Filing: 1967-03-15
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Granted: 1968-12-31
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Expires: 1987-03-15
Abstract
No abstract record available.
Inventors
- 👤 Wayne F Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:33
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/10; E21B21/103
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) | 1971-12-31 | 1972-07-01 | 1972-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-12-31 | 1976-07-01 | 1976-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-12-31 | 1980-07-01 | 1980-12-31 | $7700.00 | Window Closed / Lapsed |