Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4933240 | Wear-resistant carbide surfaces | — | 1990-06-12 |
| 4454205 | Method of drill bit manufacture and product | Ronald R. Miller, David A. Hampel, James Ault | 1984-06-12 |
| 4404760 | Excavating tooth | Frecerick C. Hahn, David A. Hampel | 1983-09-20 |
| 4335532 | Excavating tooth | Frederick C. Hahn, David A. Hampel | 1982-06-22 |