Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4803718 | Hold detecting and control circuit for a key telephone system | Victor Demjanenko, Christopher R. Caile | 1989-02-07 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4803718 | Hold detecting and control circuit for a key telephone system | Victor Demjanenko, Christopher R. Caile | 1989-02-07 |