Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6145792 | Railroad worker warning system for train conductors | George Gregory Penza | 2000-11-14 |
| 5924651 | Tactile and audible warning system for railroad workers | George Gregory Penza | 1999-07-20 |
| 5727758 | Tactile and audible warning system for railroad workers | George Gregory Penza | 1998-03-17 |