Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 9206682 | Boring element for a ground boring device | Franz-Josef Puttmann, Peter Grass, Gerhard Völkel, Frank Prutti | 2015-12-08 |
| 7337859 | Method and device for drilling a channel | Gerhard Völkel | 2008-03-04 |
| 6238141 | Apparatus for static underground drilling | Franz-Josef Puttmann, Frank Prutti, Bernhard Kaufmann | 2001-05-29 |