Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4850737 | Hydraulic spring vehicle barricade and hydraulic circuit therefor | Ralph G. Nasatka | 1989-07-25 |
| 4828011 | Countergravity casting apparatus | Paul H. Hafer, Bradley W. Hanson, Jeffrey D. Porter | 1989-05-09 |