Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5214554 | Cassette for a record carrier | Norbert C. Vollmann, Peter J. Doodson, Anton Stoger | 1993-05-25 |
| 5187629 | Cassette with magnetic tape on two coplanar reels | Norbert C. Vollmann, Jan Dewolf, Anton Stoger, Marco V. Koningsberger | 1993-02-16 |