Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| D425940 | Aerobic ski exerciser | Joseph A. Halfen, Peter Haugen, Lyle R. Hilk, Michael R. Johnston, Tianhong Ouyang +1 more | 2000-05-30 |
| 5830114 | Variable incline folding exerciser | Joseph A. Halfen, Peter Haugen, Lyle R. Hilk, Michael R. Johnston, Tianhong Ouyang +1 more | 1998-11-03 |