In order not to make nickel ring up tank, outside groove diameter ratio insidegroove is big, this on the structure solved the nickel ring grooving problem.
为了不使镍环起槽，外沟直径比内沟大，这在结构上解决了镍环起槽问题。
2
Triangular structure of the outer conductive copper wheel points inside and outside two groove, the copper wire insidegroove introduced, complete annealing.
三角结构的外层导电铜轮分内外两沟，铜线经内沟引入，完成退火。
3
A practical mechanism for the core-pulling of insidegroove was presented. The core-pulling was achieved by applying the deformation of helical spring steel sheet during the ejecting process.