Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5159139 | Drumhead with overtone suppression | Robert A. Gatzen | 1992-10-27 |
| 5107741 | Muffler for bass drums | Robert A. Gatzen | 1992-04-28 |
| 4779508 | Drumhead construction | — | 1988-10-25 |