Issued Patents All Time
Showing 1–6 of 6 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4434591 | Component useful in producing a cooling tower | Wolfgang Zerna, Hans Schafer | 1984-03-06 |
| 4407098 | Liquid storage tank with steel-reinforced concrete exterior | — | 1983-10-04 |
| 4332508 | Shield for tunneling and mining | — | 1982-06-01 |
| 4298230 | Tunnelling apparatus | — | 1981-11-03 |
| 4255366 | Process of producing a cooling tower | Wolfgang Zerna, Hans Schafer | 1981-03-10 |
| 4249870 | Climbing framework for erecting concrete forms in the manufacture of straight or curved reinforced concrete walls | Walter Simon | 1981-02-10 |