Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4380353 | Dust control system and method of operation | John Campbell, William D. Roper, Earl C. Willis | 1983-04-19 |
| 4200335 | Gauging apparatus and method, particularly for controlling mining by a mining machine | John Campbell | 1980-04-29 |