Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 8235393 | Piston ring | Johannes Esser | 2012-08-07 |
| 4973066 | Piston ring | Gerhard Duck, Albin Mierbach, Wolfgang Schmelter | 1990-11-27 |
| 4957212 | Non-circular piston rings | Gerhard Duck, Albin Mierbach | 1990-09-18 |