Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5987425 | Variable margin pricing system | David J. Hartman | 1999-11-16 |
| 5822736 | Variable margin pricing system | David J. Hartman | 1998-10-13 |
| 4865178 | Single copy vending machine for newspapers and the like | — | 1989-09-12 |