Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5633985 | Method of generating continuous non-looped sound effects | Frederick E. Severson | 1997-05-27 |
| 5590856 | Complex switch turn-out arrangements using proximity selection | Frederick E. Severson | 1997-01-07 |