Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4721182 | Personnel safety device for an underground duct particularly a sewer pipe | Arnfried Brinkmann, Udo Heuser | 1988-01-26 |
| 4607725 | Safety ladder | Arnfried Brinkmann | 1986-08-26 |