Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5209682 | Speed and direction indicator for ships | Ulrich Duning, Siegfried Lais | 1993-05-11 |
| 4519335 | Device for controlling the direction of movement and thrust force of a watercraft | Franz Krautkremer, Siegfried Lais, Detlev Stache | 1985-05-28 |