Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4949387 | Electro-acoustic transducer unit | Stefan Pieper | 1990-08-14 |
| 4821320 | Device for protecting electrical apparatus and the operator when the operator carries a high electrostatic charge | Stefan Pieper | 1989-04-11 |