Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7082726 | Butterfly valve for skylight | Joseph Prenn, Christian P. Stevens | 2006-08-01 |
| 7040061 | Tubular skylight with dome flashing and protective corrugation | David Windsor Rillie, Joseph Prenn, Christian P. Stevens | 2006-05-09 |