Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7175237 | Hewing or cutting roll | Ralf Grief | 2007-02-13 |
| 6785988 | Driving or mining machine | Egmont Lammer, Ralf Grief, Karl Lerchbaum | 2004-09-07 |
| 4770469 | Process for controlling the movement of a universally swivellable cutting arm of a partial cut cutting machine as well as apparatus for performing this process | Eduard Schellenberg, Gerhard Steinbrucker, Herwig Wrulich, Alfred Zitz | 1988-09-13 |