Top Inventors at Duff-Norton All Time
| Rank | Name | Patents |
|---|---|---|
| 1 | George R. Ferguson | 2 |
| 2 | Eckart F. Schultze | 1 |
| 3 | James C. Johnson | 1 |
| #4 | JAMES LUCAS | 1 |
| #5 | John P. Rollins | 1 |
| #6 | Ralph R. Barber | 1 |
| #7 | William Royer | 1 |
| Rank | Name | Patents |
|---|---|---|
| 1 | George R. Ferguson | 2 |
| 2 | Eckart F. Schultze | 1 |
| 3 | James C. Johnson | 1 |
| #4 | JAMES LUCAS | 1 |
| #5 | John P. Rollins | 1 |
| #6 | Ralph R. Barber | 1 |
| #7 | William Royer | 1 |