Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4683979 | Co-oscillating, volume-changing resonator in the form of a silencer | Volker Hartel, Carl Heynemann, Manfred Raubach | 1987-08-04 |
| 4570748 | Co-oscillating, volume-changing resonator in the form of a silencer | Volker Hartel, Carl Heynemann, Manfred Raubach | 1986-02-18 |