Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4846972 | Skim net assembly for cleaning swimming pools and the like | — | 1989-07-11 |
| 4824123 | Mechanical face seal for rock bits | Weng-Kwen Raymond Chia | 1989-04-25 |
| 4822057 | Mechanical face seal for rock bits | Weng-Kwen Raymond Chia | 1989-04-18 |