Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 9322216 | Annulus ring hole drill | Leung Chan | 2016-04-26 |
| 9175517 | Method and apparatus for controlling the operation of cluster drill of down-the-hole hammers | Leung Chan | 2015-11-03 |