Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4530183 | Revolving door system | Michael D. Blackston, Michael B. Zekich, John L. B. Parselle | 1985-07-23 |
| 4475308 | Revolving door system | Michael D. Blackston, Michael B. Zekich, John L. B. Parselle | 1984-10-09 |
| 4458447 | Revolving door system | Michael D. Blackston, Michael B. Zekich | 1984-07-10 |