Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7951475 | Vent valve for acid batteries | Friedrich Kramm, Christian Recker | 2011-05-31 |
| 6962761 | Vibration-resistant accumulator and method of its manufacture | Friedrich Kramm, Gunter Schmidt-Lukasch | 2005-11-08 |