Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4258232 | Line hold circuits | John D. Gillen | 1981-03-24 |
| 4188511 | Multi-link telephone intercom system | John D. Gillen, Gerald L. Edwards | 1980-02-12 |
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4258232 | Line hold circuits | John D. Gillen | 1981-03-24 |
| 4188511 | Multi-link telephone intercom system | John D. Gillen, Gerald L. Edwards | 1980-02-12 |