Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4924948 | Shock absorbing bit retaining ring | Edward V. Fritsch | 1990-05-15 |
| 4878550 | Pilot-valve-controlled percussion drilling tool | — | 1989-11-07 |
| 4799844 | Elliptical thread design | — | 1989-01-24 |
| 4714119 | Apparatus for hard rock sidewall coring a borehole | Joel Hebert | 1987-12-22 |