Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5294197 | Asphalt manufacturing assembly | Fredric W. Prill | 1994-03-15 |
| 5272833 | Soil remediation apparatus and method for same | Frederic W. Prill | 1993-12-28 |
| 5103687 | Self-adjusting trunnion assembly | — | 1992-04-14 |
| 5054931 | Counterflow asphalt drum mixer producing less hydrocarbon emissions and a method used therein | Fredric W. Prill | 1991-10-08 |
| 4839571 | Safety back-up for metering pump control | Fredric W. Prill | 1989-06-13 |
| 4337014 | Method and apparatus for erecting a portable silo and elevator | — | 1982-06-29 |