Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6508076 | Duct system for temperature-controlled cargo containers | Randal Gast, David B. Ziegler, Doug Lenz, Ming Zhang | 2003-01-21 |
| 6470692 | Air return bulkhead with filter | David B. Ziegler, Phillip R. Boudewyns, Ta Yang Yang | 2002-10-29 |
| 6364388 | Air return bulkhead for use with a transport temperature control system | David B. Ziegler, Jerry Kiesner | 2002-04-02 |