Issued Patents All Time
Showing 1–10 of 10 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7703557 | Fixed cutter bit with backup cutter elements on primary blades | Bala Durairajan, Carl M. Hoffmaster, Charles H. S. Douglas, III | 2010-04-27 |
| 6533051 | Roller cone drill bit shale diverter | Amardeep Singh, Sujian Huang, Quan Nguyen | 2003-03-18 |
| 6510909 | Rolling cone bit with gage and off-gage cutter elements positioned to separate sidewall and bottom hole cutting duty | Gary R. Portwood, Gary E. Garcia, James C. Minikus, Per Ivar Nese, Chris E. Cawthorne | 2003-01-28 |
| 6390210 | Rolling cone bit with gage and off-gage cutter elements positioned to separate sidewall and bottom hole cutting duty | Gary R. Portwood, Gary E. Garcia, James C. Minikus, Per Ivar Nese, Chris E. Cawthorne | 2002-05-21 |
| 5967245 | Rolling cone bit having gage and nestled gage cutter elements having enhancements in materials and geometry to optimize borehole corner cutting duty | Gary E. Garcia, Gary R. Portwood, James C. Minikus, Per Ivar Nese, Chris E. Cawthorne +1 more | 1999-10-19 |
| 5915486 | Cutter element adapted to withstand tensile stress | Gary R. Portwood, Scott D. McDonough | 1999-06-29 |
| 5868213 | Steel tooth cutter element with gage facing knee | Scott D. McDonough, James C. Minikus, Chris E. Cawthorne | 1999-02-09 |
| 5853055 | Rock bit with an extended center jet | Michael A. Siracki, Per Ivar Nese, Alan W. Lockstedt, Michael S. Oliver, Gary R. Portwood | 1998-12-29 |
| 5839526 | Rolling cone steel tooth bit with enhancements in cutter shape and placement | Scott D. McDonough, James C. Minikus, Chris E. Cawthorne | 1998-11-24 |
| 5833020 | Rolling cone bit with enhancements in cutter element placement and materials to optimize borehole corner cutting duty | Gary R. Portwood, Gary E. Garcia, James C. Minikus, Per Ivar Nese, Chris E. Cawthorne | 1998-11-10 |