Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5400561 | Concrete blocks having through holes for water drainage | — | 1995-03-28 |
| 5397228 | Method and device for the fabrication of perforated blocks | — | 1995-03-14 |
| 5133915 | Process for the production and treatment of concrete blocks | Hans-Josef Metten | 1992-07-28 |
| 4265834 | Process for the catalytic hydrogenation of nitrobenzene | Udo Birkenstock, Burkhard Lachmann, Herbert Schmidt | 1981-05-05 |