Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5797817 | Hydraulic tensioner with internal reservoir | Christopher T. Senftleben | 1998-08-25 |
| 5367992 | Variable camshaft timing system for improved operation during low hydraulic fluid pressure | Roger P. Butterfield, Franklin R. Smith | 1994-11-29 |
| 4873879 | Variable speed transmission | Roger P. Butterfield, Guenter Neumann | 1989-10-17 |