Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4798279 | Mine haulage method and apparatus | Richard E. Doerr, Margaret A. Roberts | 1989-01-17 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4798279 | Mine haulage method and apparatus | Richard E. Doerr, Margaret A. Roberts | 1989-01-17 |