Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4887936 | Cyclone separator with accelerator plate for pneumatic conveyor | Frank W. Christianson | 1989-12-19 |
| 4846605 | Pneumatic grain conveyor with universal frame | Frank W. Christianson | 1989-07-11 |