Issued Patents 2003
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6640914 | Percussion borer for forming bores in stone material | Erich Wisser, Marcel John, Hanspeter Schad, Cord-Henrik Surberg, Charles C. Coffin +2 more | 2003-11-04 |
| 6543977 | Concrete anchor bolt | Joachim Gunther, Marcel John, Michael Siemers, Pietro Bianchi, Erich Wisser | 2003-04-08 |