Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4836548 | Escape mechanism for sliding block puzzles | — | 1989-06-06 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4836548 | Escape mechanism for sliding block puzzles | — | 1989-06-06 |