Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 8448751 | Elevator door system | Christian G. Tonna, Helmut Schroder-Brumloop | 2013-05-28 |
| 7246688 | Elevator door system | Christian G. Tonna, Helmut Schroder-Brumloop | 2007-07-24 |