Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4522234 | Multiple conduit drill pipe | William R. Garrett | 1985-06-11 |
| 4244433 | Safety mechanism for a raise drill | — | 1981-01-13 |
| 4211291 | Drill fluid powered hydraulic system | — | 1980-07-08 |
| 4195701 | Raise drill having water passages directed toward the roller cutters | George A. Alther | 1980-04-01 |