Issued Patents All Time
Showing 1–6 of 6 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6047778 | Percussion drill assembly | James E. Coffman, Paul W. Crites, Paul Campbell | 2000-04-11 |
| 5957220 | Percussion drill assembly | James E. Coffman, Paul W. Crites, Paul Campbell | 1999-09-28 |
| 5174390 | Modular cluster drill apparatus | — | 1992-12-29 |
| 4953640 | Quick detach bit | — | 1990-09-04 |
| 4729439 | Gang drill construction | — | 1988-03-08 |
| 4512417 | Hydraulic reciprocating device | — | 1985-04-23 |