Slider for concealed slide fastener

Abstract

A slider for a concealed slide fastener includes: a lower blade; a pair of left and right rails erected along side edges of the lower blade in a left-right direction; left and right flanges extending in a direction in which the left and right flanges approach each other from upper ends of the pair of left and right rails; a guide column erected on the lower blade; and an attachment column provided above the guide column. A front end portion of each of the flanges is located forward with respect to a front end portion of each of the rails. A start point of a flange inner-front curved portion is located behind the front end portion of each of the rails.

What is claimed is: 
     
         1 . A slider for a concealed slide fastener, comprising:
 a lower blade;   a pair of left and right rails erected along side edges of the lower blade in a left-right direction;   left and right flanges extending in a direction in which the left and right flanges approach each other from upper ends of the pair of left and right rails;   a guide column erected on the lower blade; and   an attachment column provided above the guide column, wherein   a front end portion of each of the flanges is located forward with respect to a front end portion of each of the rails, and   a start point of a flange inner-front curved portion is located behind the front end portion of each of the rails.   
     
     
         2 . The slider for the concealed slide fastener according to  claim 1 , wherein
 regarding dimensions W 1  and W 0  defined below, the ratio of W 1 /W 0  is in a range of 25% to 35%,   W 0 : half the length of the entire width of the slider in the left-right direction,   W 1 : the width of the flange inner-front curved portion in the left-right direction.   
     
     
         3 . The slider for the concealed slide fastener according to  claim 1 , wherein
 a radius of curvature of the flange inner-front curved portion is in a range of 1.2 mm to 2.0 mm.   
     
     
         4 . The slider for the concealed slide fastener according to  claim 1 , wherein
 a radius of curvature of the flange inner-front curved portion is larger than a radius of curvature of a flange outer-front curved portion.   
     
     
         5 . The slider for the concealed slide fastener according to  claim 1 , wherein
 a shape of the lower blade on a frontward opening side is a substantially elliptical shape elongated in a sliding direction of the slider, a major axis of the substantially elliptical shape is oriented in a front-rear direction of the slider, and a minor axis thereof is oriented in the left-right direction of the slider.   
     
     
         6 . The slider for the concealed slide fastener according to  claim 1 , wherein
 a length D 1  in a front-rear direction of the lower blade existing forward with respect to the front end portion of each of the rails is larger than 30% of a length DO in the front-rear direction of the entire slider.