Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4900091 | Electrohydraulic coal-mining system | Ernst-Gunter Nerlich, Karl-Heinz Berger | 1990-02-13 |
| 4798417 | Method of separating the upper coal in seams | Gunter Blumenthal, Karl-Heinz Berger, Siegmar Block | 1989-01-17 |