Issued Patents 1982
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 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 |