Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4677661 | Microprocessor controlled telephone unit | Frank van Gilluwe, Douglas A. Cross | 1987-06-30 |
| 4626627 | Telephone line selector for use with a PBX | Frank van Gilluwe, Douglas A. Cross | 1986-12-02 |