Issued Patents 2016
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 9488013 | Bi-directionally raisable drilling rig mast | Robert Benjamin Donnally, Xilin Liu | 2016-11-08 |
| 9441423 | Drilling rig masts and methods of assembly and erection | Robert Benjamin Donnally, Stuart Arthur Lyall McCurdy, Xi Lin Liu, Hui SHENG, Yan Yu | 2016-09-13 |