Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4579273 | Welded pipe connection | Karl Dahmen, Heinz Gross | 1986-04-01 |
| 4247033 | Method of and device for producing multi-layer pipes | Karl Dahmen, Jurgen Engel, Heinz Gross, Werner Wennemann | 1981-01-27 |