Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4471843 | Method and apparatus for rotary drill guidance | Emrys Jones | 1984-09-18 |
| 4461359 | Rotary drill indexing system | Emrys Jones | 1984-07-24 |
| 4381161 | Slurry recovery from a circular sump | Richard E. Doerr, Hilbert D. Dahl | 1983-04-26 |
| 4283089 | Pretreatment for fracturing coal seams | Raymond L. Mazza, H. Douglas Dahl | 1981-08-11 |