Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7426965 | Power transmission unit of an impactor, a hydraulic jet impactor and the application thereof | Xinghua Tao, Guoqiang Xu, Yijin Zeng | 2008-09-23 |
| 7158886 | Automatic control system and method for bottom hole pressure in the underbalance drilling | Chunguo Yang, Bingtang Gao, Yijin Zeng, Caixuan Guo, Jianlong Zhang | 2007-01-02 |