Issued Patents 2011
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7950475 | Percussion drilling assembly having a floating feed tube | Shantanu N. Swadi, Lance D. Underwood, Jack Marshall, Kevin Edgar Harrington | 2011-05-31 |
| 7861802 | Flexible directional drilling apparatus and method | Lance D. Underwood | 2011-01-04 |