Issued Patents All Time
Showing 1–5 of 5 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4805709 | Drill bit and drill assembly | Donald D. Drummond | 1989-02-21 |
| 4541494 | Drill bit assembly | Donald D. Drummond, Roy W. Wood | 1985-09-17 |
| 4540055 | Drill bit assembly having improved operational life | Donald D. Drummond, Roy W. Wood | 1985-09-10 |
| 4515229 | Drill bit assembly with fluid separator | Donald D. Drummond, Roy W. Wood | 1985-05-07 |
| 4508183 | Method and apparatus for lubricating a drill bit | Donald D. Drummond, Roy W. Wood | 1985-04-02 |