Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4904510 | Scorch resistance perlite board | Rainer Gruber, Robert W. Eberle | 1990-02-27 |
| 4766024 | Roofing system | Kenneth N. Meehan, Robert W. Eberle | 1988-08-23 |
| 4313997 | Perlite boards and method for making same | David L. Ruff | 1982-02-02 |