Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4883132 | Drag bit for drilling in plastic formation with maximum chip clearance and hydraulic for direct chip impingement | — | 1989-11-28 |
| 4877096 | Replaceable cutter using internal ductile metal receptacles | — | 1989-10-31 |
| 4869330 | Apparatus for establishing hydraulic flow regime in drill bits | — | 1989-09-26 |