Issued Patents All Time
Showing 1–10 of 10 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6120022 | Random number selector for overhead projectors | — | 2000-09-19 |
| 5660387 | Polyhedron puzzle | — | 1997-08-26 |
| 5638308 | Calculator with keys which can selectively be disabled | — | 1997-06-10 |
| 5613463 | Numbering device | — | 1997-03-25 |
| 5590944 | Projectable timer | — | 1997-01-07 |
| D374029 | Calculator | — | 1996-09-24 |
| 5404186 | Transparent calculator for overhead projection | — | 1995-04-04 |
| D342685 | Trigonometric function overlay | — | 1993-12-28 |
| 5035502 | Transparent calculator for overhead projection | — | 1991-07-30 |
| 4949843 | One-piece multi-pocketed storage device | — | 1990-08-21 |