Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 11766078 | Lower leg sleeve | — | 2023-09-26 |
| 6085715 | Tamper resistant governor control rod cover | — | 2000-07-11 |
| 4341273 | Rotary bit with jet nozzles | Robijn Feenstra | 1982-07-27 |
| 4244432 | Earth-boring drill bits | David S. Rowley, Coy M. Fielder | 1981-01-13 |