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US3412813A
Expired / Lapsed
US
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Core drill stand
Assignee: Individual
•
Filing: 1967-06-15
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Granted: 1968-11-26
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Expires: 1987-06-15
Abstract
No abstract record available.
Inventors
- 👤 Bert E Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:27
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/02; E21B7/027; Y; Y10; Y10T; Y10T408/00; Y10T408/65; Y10T408/675; Y10T408/6779
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) | 1971-11-26 | 1972-05-27 | 1972-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-11-26 | 1976-05-27 | 1976-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-11-26 | 1980-05-27 | 1980-11-26 | $7700.00 | Window Closed / Lapsed |