Issued Patents 2004
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6799445 | Dual-use lock whose unlocking numeral combination can be traced after having been forgotten | — | 2004-10-05 |
| 6799446 | Combination lock changeable in combination | — | 2004-10-05 |
| 6711922 | Mechanism of a combination lock for beginning and ending combination-changing operation | — | 2004-03-30 |