Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6475880 | Cassette invertor method | Willard L. Hofer | 2002-11-05 |
| 6254682 | Cassette invertor apparatus | Willard L. Hofer | 2001-07-03 |
| 5858459 | Cassette invertor apparatus and method | Willard L. Hofer | 1999-01-12 |