Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4316515 | Shaft drill bit with improved cutter bearing and seal arrangement and cutter insert arrangement | — | 1982-02-23 |
| 4248314 | Shaft drill bit with overlapping cutter arrangement | Robert A. Cunningham | 1981-02-03 |