US3667784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill rod structure
Assignee: Heath and Sherwood Drilling Ltd
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Filing: 1970-04-03
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Granted: 1972-06-06
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Expires: 1990-04-03
Abstract
Abstract THE INVENTION RELATES TO A DRILL ROD STRUCTURE HAVING ALUMINUM ALLOY DRILL PIPE AND STEEL COUPLINGS. THE JOINTS BETWEEN THE PIPE AND COUPLINGS ARE THREADED AND THE DRILL ROD HAS SUBSTANTIALLY UNIFORM INSIDE AND OUTSIDE DIAMETERS. THE INVENTION RELATES TO DRILL RODS OF SUBSTANTIALLY LARGE SIZE, SAY, EXCEEDING ABOUT TWO INCHES IN OUTSIDE DIAMETER.
Inventors
- 👤 Lyle W Hokanson
- 👤 John W Mcbean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:42
CPC Classifications
E; E21; E21B; E21B17/00; E21B17/02; E21B17/04; E21B17/042; E21B17/0423
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |