Why does a zipper lock when you pull it?

Zipper, also known as zipper, is a repeatable pull, pull open by two flexible meshing of each other.
It is one of the most important inventions in the world in more than one hundred years. The common forms of zipper include single head closed tail type, double head closed tail type, double head open tail type and so on.
Answer 1: chain tooth has the cent of size, tooth form each has different, pull head modelling to abound change, can make handle, can make adornment again.
The puller is also safe, and will not slide off automatically after the zipper is pulled: the working principle of the zipper is very simple, that is, two zipper straps can be pulled or pulled at will through the puller.
Solution 2: How the chain works is that each tooth is a small hook that matches a hole under a small tooth on the opposite side of the other strap.
The zipper is strong enough to open only when the slider slides open the teeth.