The zipper is a commonly used closure throughout garments and bags in the everyday world. It is a simple tool with simple mechanics. Yet, it definitely is considered a great technological advancement, especially in the fashion/garment industry.
The zipper works because of a device that is much older than the 80 years the zippers has been around. The wedge and hook is what allows the zipper to open and close with ease. The wedge can be identified as the pull portion of the zipper and the hook can be identified as the teeth of zipper.
A zipper has two rows of teeth on each side facing one another. Each one of the teeth has a hook and they are offset from one another so as they are pulled towards one another they connect in sequence. A zipper is closed when the hooks into those hollow areas. In order for this to happen each of the teeth and hollows must be identical in size and shape.The slide portion of the zipper contains wedges that push the hooks and hollows together at specific angles to close it. In order to unzip the closure the pull is pushed against the hooks in the opposite direction and detaches the teeth. The stops at each end of the zipper are what keeps the pull from sliding completely off the tracks of teeth.