Issued Patents 1997
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5664606 | Drill pipe having concave wrenching recesses | — | 1997-09-09 |
| 5649745 | Inflatable gripper assembly for rock boring machine | — | 1997-07-22 |
| 5598895 | Cutter assembly having a plurality of independently rotatable cutting units thereon | Gregory L. Hern | 1997-02-04 |