Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6196544 | Three-dimensional puzzle | — | 2001-03-06 |
| 4926400 | Combined twenty-four (24)/twenty-five (25) hour clock | Guy B. Irving | 1990-05-15 |
| 4541726 | Twenty-five (25) hour clock | — | 1985-09-17 |