Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6531430 | Engines lubricated with vegetable oil lubricants | Duane L. Johnson | 2003-03-11 |
| 5888947 | Vegetable oil lubricants for internal combustion engines and total loss lubrication | Duane L. Johnson | 1999-03-30 |