Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4378132 | Mining method and apparatus | Klaus Spies | 1983-03-29 |
| 4277204 | Excavation roof support and method of installing the same | Manfred Koppers, Karlheinz Bohnes | 1981-07-07 |