Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4468367 | Method of uniting a plastic fixation part with a sealing body | Warner Uan de Putter | 1984-08-28 |
| 4432395 | Pipe part with socket provided with longitudinally extending channels | Roelof H. Marissen | 1984-02-21 |
| 4428591 | Plastic pipe provided with a groove | Roelof H. Marissen | 1984-01-31 |
| 4344461 | Pipe part with socket provided with longitudinally extending channels | Roelof H. Marissen | 1982-08-17 |
| 4338716 | Plastic pipe provided with a groove | Roelof H. Marissen | 1982-07-13 |