Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7523713 | Use of floatation material to support a vehicle in water | — | 2009-04-28 |
| D314388 | Endless track work vehicle | Thomas D. Brewer, John M. Parks, Gerald P. Simmons | 1991-02-05 |
| 4881609 | Suspension mechanism for a track-type vehicle | Robert J. Purcell | 1989-11-21 |
| 4874052 | Suspension system for a vehicle | Robert J. Purcell | 1989-10-17 |
| 4819754 | Multiple mode vehicle suspension system | Robert J. Purcell | 1989-04-11 |
| 4817746 | Suspension mechanism for a track-type vehicle | Robert J. Purcell, Gerald P. Simmons | 1989-04-04 |