Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4273964 | Ring and tone plant | — | 1981-06-16 |
| 4211895 | Electronic telephone system with time division multiplexed signalling | John C. Davis, Krishnaswamy Natarajan, Jan Cihal, Jeffrey Sidwell | 1980-07-08 |