Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4825616 | Roofing shingle | Alfredo A. Bondoc, Frederick W. Sieling | 1989-05-02 |
| 4795661 | Process for the manufacture of asphalt shingles | Alfredo A. Bondoc, Duane A. Davis, Bruno E. Magnus | 1989-01-03 |