Assignee

YU LICHENG

CN2 patents

Top patents by PatentIndex Score

US10760367B2Sep 1, 2020

Wellhead sealing device of sucker-rod pumping machine

YU LICHENG2 citations61

US11261687B2Mar 1, 2022

Wellhead sealing device of sucker-rod pumping machine

YU LICHENG0 citations51