Issued Patents All Time
Showing 1–5 of 5 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5456605 | Telephone training apparatus and method | Edward A. Pekol, David A. Rogala | 1995-10-10 |
| 5369680 | Pro-active billing and routing test set | Douglas Alan Hahn, Thomas W. Mines | 1994-11-29 |
| 5060256 | Mass polling system with cut-through | Robert W. Walker | 1991-10-22 |
| 4937850 | Programmable automatic call-thru set | Robert D. Hahn, Douglas Alan Hahn | 1990-06-26 |
| 4794633 | Mass polling system | Robert W. Walker | 1988-12-27 |