Issued Patents 1982
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4327526 | Apparatus for grinding the internal walls of pipes | William H. Pettyjohn, William E. Milligan, deceased | 1982-05-04 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4327526 | Apparatus for grinding the internal walls of pipes | William H. Pettyjohn, William E. Milligan, deceased | 1982-05-04 |