Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4327526 | Apparatus for grinding the internal walls of pipes | William H. Pettyjohn, John Lewis | 1982-05-04 |
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4327526 | Apparatus for grinding the internal walls of pipes | William H. Pettyjohn, John Lewis | 1982-05-04 |