Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4889195 | Drill bit direct drive for deep well drilling tools | Volker Kruger | 1989-12-26 |
| 4854401 | Drill bit direct drive for deep well drilling tools | Volker Kruger | 1989-08-08 |
| 4629013 | Drive device for a drill bit | Volker Kruger | 1986-12-16 |