Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4969778 | Expansion assembly for mine roof bolts utilized in small diameter bore holes | Frank Calandra, Jr., John C. Stankus, Paul Yacisin | 1990-11-13 |
| 4904123 | Expansion assembly for mine roof bolts utilized in small diameter bore holes | Frank Calandra, Jr., John C. Stankus, Paul Yacisin | 1990-02-27 |