Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| RE36452 | Composite seal for rotary cone rock bits | Robert G. Upton, Michael Hooper, Robert X. Chambers, Gary R. Portwood, Randy Johnston | 1999-12-21 |
| 5362073 | Composite seal for rotary cone rock bits | Robert G. Upton, Michael F. Hooper, Gary R. Portwood, Randy Johnston, Robert X. Chambers | 1994-11-08 |