Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4872194 | Method for transmission of alarm signals utilizing an entrance telephone system | — | 1989-10-03 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4872194 | Method for transmission of alarm signals utilizing an entrance telephone system | — | 1989-10-03 |