Slide fastener slider

Claim 1

A slider, for a slide fastener including a pair of stringer tapes carrying along their inner longitidunal edges of a pair of rows of fastener elements in a form of coiled plastic filaments of substantially oval contour having upper and lower leg portions and coupling head portions, comprising: (a) a slider body including a pair of upper and lower wings joined at their front end by a neck to define a Y-shaped guide channel between said upper and lower wings for the passage of the fastener element rows of the slide fastener, said upper wing having an aperture opening into said guide channel, said lower wing having a base and a pair of flanges respectively projecting from opposite lateral edges of said base; (b) a pair of raised corner ledges on an inner face of said base of said lower wing adjacent to said flanges respectively, each of said corner ledges extending along an inner face of the respective flange through its length and having an inwardly sloping surface engageable with the lower leg portions of the respective fastener element row; and (c) a pair of auxiliary ledges on the inner face of said base of said lower wing adjacent to respective front ends of said flanges, each of said auxiliary ledges having a top surface disposed below said sloping surface of the respective corner ledge for being engageable with the lower leg portion of the respective fastener element row, said auxiliary ledge having a uniform height throughout its whole area and extending from a midportion of the respective corner ledge beyond the front end thereof.