Zipper Slide for Double-Layer Nylon Zipper

Abstract

A zipper slide so configured that the retracted design of the rear side of the bottom slide body block relative to the top slide body block provides sufficient space for allowing the inner layer of the double-layer nylon zipper to be smoothly curved when the zipper slide is cornering, reducing zipper friction resistance and prolonging the zipper lifespan; the upper guard flanges are relatively longer than the lower guard flanges so that the upper guard flanges are kept relatively closer to the center block than the lower guard flanges to shift the fulcrum forward, enabling each of integrated opposing left and right series of interlocking teeth of the double-layer nylon zipper to face toward the fulcrum and the center block when each of integrated opposing left and right series of interlocking teeth of the double-layer nylon zipper is opened to the extent.

What is claimed is: 
     
         1 . A zipper slide used in double-layer nylon zipper, comprising a top slide body block having opposite front and rear sides, a bottom slide body block having opposing front and rear sides, two upper guard flanges respectively downwardly extended from two opposite lateral sides of said top slide body block, two lower guard flanges respectively upwardly extended from two opposite lateral sides of said bottom slide body block, a center block connected between said top slide body block and said bottom slide body block, and a tongue-shaped guide plate forwardly extended from a front middle part of said center block and equally spaced between said top slide body block and said bottom slide body block for separating upper and lower fabric tapes of the double-layer nylon zipper, wherein: the front sides of said top slide body block and said bottom slide body block are kept in vertical alignment, the rear side of said bottom slide body block is retracted relative to the rear side of said top slide body block, and the retraction distance is about equal to the thickness of one layer of zipper chain tape thickness of the double-layer nylon zipper; the zipper slide further comprises a connection part connected between the rear side of said bottom slide body block and a bottom side of said center block to reinforce the tensile strength of said top slide body block and said bottom slide body block. 
     
     
         2 . The zipper slide used in double-layer nylon zipper as claimed in  claim 1 , wherein said upper guard flanges are relatively longer than said lower guard flanges so that said upper guard flanges are kept relatively closer to said center block than said lower guard flanges to shift the fulcrum forward, enabling each of integrated opposing left and right series of interlocking teeth of the double-layer nylon zipper to face toward said fulcrum and said center block when each of integrated opposing left and right series of interlocking teeth of the double-layer nylon zipper is opened to the extent. 
     
     
         3 . The zipper slide used in double-layer nylon zipper as claimed in  claim 1 , wherein the zipper slide further comprises two upper guide grooves located on a rear part of a bottom surface of said top slide body block at two opposite lateral sides relative to said center block, and two lower guide grooves located on a rear part of a top surface of said bottom slide body block at two opposite lateral sides relative to said center block. 
     
     
         4 . The zipper slide used in double-layer nylon zipper as claimed in  claim 3 , wherein said upper guide grooves and said lower guide grooves each have an entrance at an outer side thereof, said entrance having a width equal to the width of the interlocking teeth and a depth in the range about ⅛˜¼ of the thickness of integrated opposing left and right series of interlocking teeth of the double-layer nylon zipper.