Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4803458 | Control switch and potentiometer for hearing aids and the like | John A. Trine, David A. Samdahl | 1989-02-07 |
| 4803599 | Mounting bar structure for electrical signalling and indicating devices | John A. Trine | 1989-02-07 |