Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4330687 | Audio and full duplex digital data carrier system | John D. Foulkes, David K. Worthington | 1982-05-18 |
| 4302629 | Digital data transmission system | John D. Foulkes, David K. Worthington | 1981-11-24 |
| 4207555 | Lock system | — | 1980-06-10 |