Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6299660 | Accordion filter with a protective mask | Hans-Joachim Lippold, Markus Fronhofer, Hans Leibold | 2001-10-09 |
| 6146436 | Cartridge filter | Anthony Hollingsworth, Jorg Sievert, Thomas Schroth, Antje Rudolph | 2000-11-14 |