Top Inventors at Keystone Engineering All Time
| Rank | Name | Patents |
|---|---|---|
| 1 | Rudolph A. Hall | 8 |
| 2 | Wayne H. Tuttle | 5 |
| 3 | Ian Ballinger | 4 |
| #4 | Conrad M. Fritz | 3 |
| #5 | Ralph Shaw | 3 |
| #6 | Robert C. Manning | 1 |
| Rank | Name | Patents |
|---|---|---|
| 1 | Rudolph A. Hall | 8 |
| 2 | Wayne H. Tuttle | 5 |
| 3 | Ian Ballinger | 4 |
| #4 | Conrad M. Fritz | 3 |
| #5 | Ralph Shaw | 3 |
| #6 | Robert C. Manning | 1 |