Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4835829 | Hub assembly | Hans-Heinrich Welschof, Rudolf Beier | 1989-06-06 |
| 4797018 | Ribbon cassette and method for operating an electronically controlled typewriter | Rudolf Spotka | 1989-01-10 |