Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 11171580 | Brake system and controller for use with a wellhead direct drive | Al Duerr, John Doyle, Wray Sparling | 2021-11-09 |
| 10221633 | Sucker rod shear couplers | Arnold Wollmann, Wray Sparling, John Doyle | 2019-03-05 |