Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6752223 | Roller cone bit with improved seal gland design | Mark P. Blackman, Guy Lefort | 2004-06-22 |
| 6279671 | Roller cone bit with improved seal gland design | Mark P. Blackman, Guy Lefort | 2001-08-28 |