Due to the special structure of controlled direction well, it can lead to severe abrasion even jamming if not adopting any measure when using progressing cavity pump rod to pump oil.
由于定向井井身结构特殊，利用螺杆泵进行抽油时如不采取任何措施势必造成杆柱严重磨损甚至卡死。
2
The utility model can not only lead a setline lover to use a very long fishing rod to fish, but also can cut off or set off as well as throw a fish hook conveniently.
本实用新型不但能使钓鱼线爱好者使用很长的钓鱼杆钓鱼，而且还可方便地收放钓鱼线和抛鱼钩。
3
The flapping mechanism adopts a parallel quadrilateral connecting rod mechanism to lead the tail fin of the robotic fish arranged on a tail fin frame to make periodic translational motion.