Fun with Patents!
This week we have the “Fluid operated zipper” (US3517423). Apparently the ‘problem’ is that when conventional zipper teeth are spread apart, the teeth remain exposed and are frequently sharp enough so that a person can inadvertently cut their hands. Unlike conventional zippers, the inventor’s solution relates to a fluid operated zipper incorporating interlocking half sections, parts of which are withdrawn from the edges when spread apart, so there are no sharp bits lying in wait to stab you.
A great idea but could be embarrassing if the fluid container leaks!