Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| RE33439 | Drainage channel with locking grate | Roland Thomann, Heinz Witschi, Markus-Christian Amann | 1990-11-13 |
| 4621939 | Drainage channel | Roland Thomann, Heinz Witschi, Markus-Christian Amann | 1986-11-11 |