Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7069662 | Drill level indicator | George Fung, Vincent P. Cooper, Leo Driessen, Chan Ka Shing | 2006-07-04 |
| 6810596 | Drill level indicator | George Fung, Vincent P. Cooper, Leo Driessen, Chan Ka Shing | 2004-11-02 |