Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4381161 | Slurry recovery from a circular sump | Richard E. Doerr, Ronald W. Umphrey | 1983-04-26 |
| 4305474 | Thrust actuated drill guidance device | Nathandale Farris | 1981-12-15 |
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4381161 | Slurry recovery from a circular sump | Richard E. Doerr, Ronald W. Umphrey | 1983-04-26 |
| 4305474 | Thrust actuated drill guidance device | Nathandale Farris | 1981-12-15 |