Issued Patents 2019
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 10196863 | Connection structure between pipe body and steel joint of aluminum alloy drill pipe | Yonggang Liu, Xiaojun Li, Fangpo Li | 2019-02-05 |
| 10184596 | Connection structure between pipe body and joint of aluminum alloy drill pipe | Yonggang Liu, Fangpo Li, Qi Shi | 2019-01-22 |