Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5261458 | Pilot relay valve with load piston | Duane R. Johnson, Robert J. Herbst, James E. Fent, Paul O. Szentkiralyi | 1993-11-16 |
| 4691968 | Dual circuit brake valve | Duane R. Johnson, Roy E. Bartholomew | 1987-09-08 |
| 4553789 | Dual brake valve with brake proportioning | Richard W. Carmichael | 1985-11-19 |