Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6187255 | Method for producing building materials | — | 2001-02-13 |
| 5649987 | Process for producing tabular building and decorative materials similar to natural stone | — | 1997-07-22 |
| 4927442 | Method of producing open-pore sintered glass filters and product | Werner Kiefer, Veronika Rehm | 1990-05-22 |