Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5769183 | Drive unit for a self-propelled elevator car | Utz Richter, Christoph Liebetrau, Helmut Heizmann, Ortwin Piper | 1998-06-23 |
| 5713432 | Drive frame for a self-propelled elevator car | Utz Richter, Christoph Liebetrau, Ortwin Piper, Helmut Heizmann | 1998-02-03 |