Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4980887 | Digital communication apparatus and method | Donald R. Casady | 1990-12-25 |
| 4768227 | Coil operated telephone | Jack M. Grubbs | 1988-08-30 |
| 4698840 | Coin operated telephone | Jack M. Grubbs | 1987-10-06 |