Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5136585 | Digital key telephone system | Alan Stanley John Chapman, John W. Williams, Alan M. Redmond | 1992-08-04 |
| 5027345 | Digital key telephone system | Timothy J. Littlewood, David Joseph Robertson, Ronald J. Maginley, Alan Stanley John Chapman, Terence Neil Thomas | 1991-06-25 |
| 4893310 | Digital key telephone system | David Joseph Robertson, Ronald J. Maginley, Alan Stanley John Chapman, Terence Neil Thomas, John W. Williams +2 more | 1990-01-09 |
| 4626628 | Telephone line circuit having time-shared DTMF receivers | Johann D. Ramsaran, Bora Biray, Anthony Yung | 1986-12-02 |