Issued Patents 1982
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4323339 | Device for manufacturing plastics pipes with oblong channels | Jan P. van Dongeren | 1982-04-06 |
| 4321228 | Method of and apparatus for manufacturing a plastic pipe comprising longitudinally extending hollow channels in its wall | — | 1982-03-23 |