Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7140448 | Stepped polycrystalline diamond compact insert | Roy D. Estes | 2006-11-28 |
| 5289889 | Roller cone core bit with spiral stabilizers | Marvin Gearhart, Paul G. Parys | 1994-03-01 |