Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4298774 | Call waiting signal arrangement | — | 1981-11-03 |
| 4191857 | Digital trunk supervisory decoder multiplexor for ground start or E&M signalling on a common T1 span | Donald W. McLaughlin | 1980-03-04 |
| 4190745 | Call for service and continuity sensor circuit | David Q. Lee, Richard M. Rovnyak | 1980-02-26 |