Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4935956 | Automated public phone control for charge and collect billing | James B. Hellwarth, David C. Hellwarth, Jan G. Hellwarth | 1990-06-19 |
| 4418383 | Data flow component for processor and microprocessor systems | Donald E. Doyle, Jack L. Quanstrom | 1983-11-29 |