Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4830123 | Mounting means for cutting elements in drag type rotary drill bit | Jeffery E. Daly | 1989-05-16 |
| 4794994 | Drag drill bit having improved flow of drilling fluid | John D. Deane | 1989-01-03 |