Issued Patents All Time
Showing 1–11 of 11 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6474423 | Drill bit (A) | — | 2002-11-05 |
| 6390212 | Drill bit (b) | — | 2002-05-21 |
| 6330923 | Sealing bearings in drill bits | — | 2001-12-18 |
| 5709416 | Threaded coupling-tool joint | — | 1998-01-20 |
| 5096210 | Double face oven seal | Alex F. Farris, III, Danny R. Morrow, D. O. Harden | 1992-03-17 |
| 4754818 | Method of measuring drill bit fluid flow | — | 1988-07-05 |
| 4727943 | Rotary drill bit | — | 1988-03-01 |
| 4541494 | Drill bit assembly | Donald D. Drummond, Walter F. Johnsey | 1985-09-17 |
| 4540055 | Drill bit assembly having improved operational life | Donald D. Drummond, Walter F. Johnsey | 1985-09-10 |
| 4515229 | Drill bit assembly with fluid separator | Donald D. Drummond, Walter F. Johnsey | 1985-05-07 |
| 4508183 | Method and apparatus for lubricating a drill bit | Donald D. Drummond, Walter F. Johnsey | 1985-04-02 |