Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4737051 | Mobile mine-roof support | — | 1988-04-12 |
| 4474510 | Hydraulic mine-roof support | — | 1984-10-02 |
| 4380410 | Mine-roof support | Gerhard Ewich, Gunther Kuschke, Alfred Maykemper, Josef Welzel | 1983-04-19 |
| 4330226 | Roof-support distancing apparatus | Josef Welzel, Alfred Maykemper | 1982-05-18 |