Issued Patents 2011
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7991554 | Method for predicting rate of penetration using bit-specific coefficients of sliding friction and mechanical efficiency as a function of confined compressive strength | William Malcolm Calhoun, Hector Ulpiano Caicedo | 2011-08-02 |