Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4882099 | Aeration apparatus havine a deicing mechanism and control circuit therefor | Thomas Giese | 1989-11-21 |
| 4806251 | Oscillating propeller type aerator apparatus and method | — | 1989-02-21 |