Slider for slide fastener

A slider for a slide fastener including a pair of stringer tapes carrying along their inner longitudinal edges a pair of rows of coupling elements, each coupling element having a leg portion mounted on the longitudinal edge and a coupling head projecting beyond the longitudinal edge transversely of the stringer tape, said slider comprising:

• (a) a slider body including a pair of parallel spaced wings joined at their front end by a neck so as to define therebetween a substantially Y-shaped guide channel for the passage of the rows of coupling elements, at least one of said wings having a pair of flanges projecting from opposite lateral edges thereof toward the other wing and defining therebetween a portion of said guide channel;
• (b) each of said wings having a front edge extending between said opposite lateral edges thereof across said neck, said front edge having a pair of outer portions respectively disposed adjacent to said opposite lateral edges and projecting forwardly beyond a pair of planes extending respectively between a front end of said neck and respective front ends of said flanges;
• (c) each of said wings having a pair of sloped interior guide surfaces extending respectively along said outer portions of said front edge and facing forwardly of said slider body, said guide surfaces being engageable with the leg portions of the coupling elements;
• (d) said front edge further having a pair of inner portions disposed one on each side of said neck, each said inner portion terminating short of a corresponding one of said planes, each of said wings having a further pair of sloped guide surfaces extending respectively along said inner portions of said front edge and facing forwardly of said slider body, said further pair of guide surfaces being engageable with the coupling heads of the coupling elements;
• and
• (e) said pair of guide surfaces and said further pair of guide surfaces having different widths and sloping at different camming angles.