Issued Patents 1994
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5322136 | Air percussion drilling assembly | Huy D. Bui | 1994-06-21 |
| 5305837 | Air percussion drilling assembly for directional drilling applications | Roger Johns, Huy D. Bui | 1994-04-26 |