Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6047778 | Percussion drill assembly | James E. Coffman, Paul Campbell, Ewald H. Kurt | 2000-04-11 |
| 5957220 | Percussion drill assembly | James E. Coffman, Paul Campbell, Ewald H. Kurt | 1999-09-28 |
| 5662180 | Percussion drill assembly | James E. Coffman, Paul Campbell | 1997-09-02 |