Issued Patents All Time
Showing 76–79 of 79 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4969778 | Expansion assembly for mine roof bolts utilized in small diameter bore holes | Frank Calandra, Jr., Mike Cokus, Paul Yacisin | 1990-11-13 |
| 4904123 | Expansion assembly for mine roof bolts utilized in small diameter bore holes | Frank Calandra, Jr., Mike Cokus, Paul Yacisin | 1990-02-27 |
| 4865489 | Mine roof anchor having adjustable resin retaining washer | Eugene H. Stewart, Glen S. Grissinger | 1989-09-12 |
| 4861198 | Expansion assembly for mine roof bolts | — | 1989-08-29 |