The technology of the pull-spring parts was analyzed, the particular progressive structure and arrange layout was introduced.
分析了拉簧钩件的工艺性，介绍了其特殊级进模总体设计结构和排样方案。
2
If you put your fingers between the crevice at the bottom, and here's where you gotta watch out for the spring, pull the thing apart and that's it.
如果你把手指放到底部的缝隙中间，这里你需要小心弹簧，把东西分开，就是这样。
3
Now I replace this object by mass m2 but the extension is the same, so the pull must be same the spring doesn't know what the mass is at the other end, right?