Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5636712 | Apparatus for driving a self-propelled elevator | Wolfgang Muller, Christoph Liebetrau, Jurgen Kastle, Albrecht Morlok, Helmut Heizmann | 1997-06-10 |
| 5615864 | Elevator hoist apparatus with torque support device | Christoph Liebetrau | 1997-04-01 |