Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4840249 | Apparatus for srewing a cover onto a screw neck of a hearing aid | Ulrich Birkholz, Peter Nassler | 1989-06-20 |
| 4834927 | Method and apparatus for producing an ear impression | Ulrich Birkholz, Peter Nassler | 1989-05-30 |