Slide fastener

1. A slide fastener ( 1 ), comprising:

a pair of left and right fastener stringers ( 2 ) each having an element row ( 4 ) at each of opposing edge portions of left and right fastener tapes ( 3 ); and a slider ( 10 , 110 ) being configured to engage the element rows ( 4 ) by moving forward between the pair of left and right fastener stringers ( 2 ) and to disengage the element rows ( 4 ) by moving backward,

wherein the slider ( 10 , 110 ) comprises:

an upper wing plate ( 20 , 120 ); a lower wing plate ( 30 , 30 A, 130 );

a guide pillar ( 11 , 111 ) for connecting the upper wing plate ( 20 , 120 ) to the lower wing plate ( 30 , 30 A, 130 );

a Y-shaped element path ( 40 ) defined between the upper wing plate ( 20 , 120 ) and the lower wing plate ( 30 , 30 A, 130 );

left and right shoulder openings ( 41 ) that are open forward the element path ( 40 ); and

a rear opening ( 42 ) that is open backward the element path ( 40 );

wherein each of the upper wing plate ( 20 , 120 ) and the lower wing plate ( 30 , 30 A, 130 ) has left and right front end sides ( 21 a , 31 a , 131 a ) that form opening ends of the left and right shoulder openings ( 41 );

wherein at least one of the upper wing plate ( 20 , 120 ) and the lower wing plate ( 30 , 30 A, 130 ) has one or more concave portions ( 31 B, 31 C, 131 B) recessed backward from the left and right front end sides ( 21 a , 31 a , 131 a ); and

wherein a depth (D, Dx) of each of the concave portions ( 31 B, 31 C, 131 B) recessed backward from the left and right front end sides ( 21 a , 31 a , 131 a ) is larger than zero, and less than or equal to a distance to each of end points (P, P 1 ) of R of the guide pillar ( 11 , 111 ),

wherein at least one of the upper wing plate ( 20 , 120 ) and the lower wing plate ( 30 , 30 A, 130 ) comprises left and right flanges ( 24 , 34 ) that define left and right outer side surfaces of the element path ( 40 ) as inward surfaces ( 25 , 35 ),

wherein each of the inward surfaces ( 25 , 35 ) of the left and right flanges ( 24 , 34 ) comprises a first inward surface ( 26 , 36 ) that intersects with an outer end ( 21 aa , 31 aa ) of each of the left and right front end sides ( 21 a , 31 a , 131 a ),

wherein the element path ( 40 ) comprises:

branched portions ( 40 A) defined on left and right sides of the guide pillar ( 11 , 111 ), the branched portions ( 40 A) being open at the left and right shoulder openings ( 41 ); and

a confluent portion ( 40 B) extending backward from the branched portions ( 40 A) and being open at the rear opening ( 42 ),

wherein the left and right flanges ( 24 , 34 ) include branched flange portions ( 24 A) corresponding to the branched portions ( 40 A),

wherein each of the branched flange portions ( 24 A) includes the first inward surface ( 26 ); and a second inward surface ( 27 ) extending backward from the first inward surface ( 26 ), the second inward surface ( 26 ) being angled with respect to the first inward surface ( 26 ), and

wherein an inclination angle with respect to a left-right intermediate axis (Ax) of the slider ( 10 ) is larger for the second inward surface ( 27 ) than for the first inward surface ( 26 ).

2. The slide fastener according to claim 1 , wherein a front end portion ( 111 a ) of the guide pillar ( 111 ) is inclined so as to gradually project forward from the lower wing plate ( 130 ) to the upper wing plate ( 120 ).

3. The slide fastener according to claim 1 , wherein the depth (D, Dx) of each of the concave portions ( 31 B, 31 C, 131 B) depressed backward from the left and right lower front end sides ( 21 a , 31 a , 131 a ) is larger than 0% and less than or equal to 20% of a length (TL) of the slider ( 10 , 110 ) in a front-rear direction.

4. The slide fastener according to claim 1 , wherein the slide fastener ( 1 ) has coiled element rows ( 4 ) on only one of front and back surfaces of the fastener tapes ( 2 ), and in reverse use for using the side having the element row ( 4 ) as a back surface, the depth (D, Dx) of each of the concave portions ( 31 B, 31 C, 131 B) recessed backward from the left and right front end sides ( 21 a , 31 a , 131 a ) is larger than 0% and less than or equal to 35.0% of a length (TL) of the slider ( 10 , 110 ) in a front-rear direction.

5. The slide fastener according to claim 1 , wherein one or more of the concave portions ( 31 B, 131 B) are provided between the left and right front end sides ( 31 a , 131 a ).

6. The slide fastener according to claim 1 , wherein a shoulder opening width (W 1 , W 2 ) of each of the left and right shoulder openings ( 41 ) in a direction along the left and right front end sides ( 21 a , 31 a , 131 a ) is larger than 1 time and less than or equal to 1.1 times a width of one element ( 4 a ), along a left-right direction, of the element row ( 4 ).

7. The slide fastener according to claim 6 ,

wherein each of the shoulder opening widths (W 1 , W 2 ) is a distance between an outer end ( 21 aa , 31 aa ) of the left and right front end sides ( 21 a , 31 a , 131 a ) and an inner end ( 21 ab , 31 ac ) of the left and right front end sides ( 21 a , 31 a , 131 a ), or a distance between the outer end ( 21 aa , 31 aa ) of the left and right front end sides ( 21 a , 31 a , 131 a ) and a virtual inner end ( 31 ab ) of the left and right front end sides ( 21 a , 31 a , 131 a ) in a region of each of the concave portions ( 31 B, 131 B), and

wherein the inner end ( 21 ab , 31 ac ) or the virtual inner end ( 31 ab ) is on a virtual line (E) in which each of the left and right ends of the guide pillar ( 11 ) is extended forward in parallel with the left-right intermediate axis (Ax) of the slider ( 10 ).

8. The slide fastener according to claim 1 ,

wherein the first inward surface ( 26 , 36 ) of each of the left and right flanges ( 24 , 34 ) and each of the left and right front end sides ( 21 a , 31 a , 131 a ) form an obtuse angle (θ1, θ2).

9. The slide fastener according to claim 1 , wherein a front end of the guide pillar ( 11 ) is located backward from the left and right front end sides ( 21 a , 31 a ) and the concave portions ( 31 B, 31 C).

10. The slide fastener according to claim 1 , wherein one or more of the concave portions ( 31 C) are provided at each of the left and right front end sides ( 31 a ).

11. The slide fastener according to claim 1 ,

wherein the slider ( 10 , 110 ) includes left and right gaps (G) between the upper wing plate ( 20 , 120 ) and the lower wing plate ( 30 , 30 A, 130 ) for passing the left and right fastener tapes ( 3 ) corresponding to the element rows ( 4 ) in the element path ( 40 ),

wherein each of the left and right fastener tapes ( 3 ) includes a thick portion ( 7 ) along a longitudinal direction, the thick portion ( 7 ) restricting entry of the left and right fastener tapes ( 3 ) into the element path ( 40 ) through the left and right gaps (G), and

wherein a length (H) of each of the thick portions ( 7 ) in an up-down direction is larger than a distance of each of the gaps (G) in the up-down direction.