Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4870990 | Double-flow butterfly valve part | Rudolf Bierling, Wilhelm Hannibal | 1989-10-03 |
| 4838217 | Cast iron camshaft for internal combustion engines | Erwin Korostenski | 1989-06-13 |