Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5672041 | Collapsible, powered platform for lifting wheelchair | Lynn O. Ringdahl, James B. Welte, Gary G. Gruber, Timothy W. Jenum | 1997-09-30 |
| 5401135 | Foldable platform wheelchair lift with safety barrier | Lynn O. Ringdahl | 1995-03-28 |