Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5627833 | Digital added main line system with power-up and power-down features | — | 1997-05-06 |
| 5598455 | Alarm and test system for a digital added main line | Anthony Vranicar, Philip B. Vail, Gerald L. Shimirak, Julian S. Mullaney | 1997-01-28 |