SLIDE FASTENER

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC § 119 to Japanese Utility Model Application No. 2024-003089 filed on Sep. 13, 2024, the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a slide fastener.

BACKGROUND

Patent Literature 1 discloses a self-sealing closure system. As schematically illustrated in FIGS. 1 and 2 of Patent Literature 1, the self-sealing closure system includes a first part 01 for interconnecting with a second part 02, and each of the parts 01 and 02 includes a plurality of geometrically arranged small nodules 03. Each small nodule 03 has a bulbous upper surface 04 and a planar lower surface 05 that coincides with a common joint surface 14. By application of a relative compressive force C, corresponding respective nodules 03 and 03′ of each of the parts 01 and 02 are squeezed through corresponding receptor opening portions 13 and 13′ and elastically expand into the corresponding respective receptors 06 and 06′, causing the first part 01 to interlock with the second part 02 and each nodule 03 to be rolled into the corresponding receptor 06. Accordingly, the first part 01 and the second part 02 can be fastened together.

The first and second parts 01 and 02 may be engaged in generally aligned unconnected parts by application of a typical compressive force, such as a pressure applied between a thumb and index finger, but may also be engaged by a cursor 20 that slides in a longitudinal direction. As schematically illustrated in FIGS. 4A to 4D of Patent Literature 1, the cursor 20 includes: an entrance chamber 21 having walls 22 aligned in the longitudinal direction; a separator bar 23 separating separate entrance slots above and below for each of the parts 01 and 02; a chamber 24 which is tapered in the longitudinal direction for pressing the nodules 03 and 03′ into corresponding respective receptor opening portions 13 and 13′; an exit chamber 26 terminating in a chamfered port 27; and pull tabs 30 and thumb tabs 33 for applying opening and closing forces A and B in the longitudinal direction.

When the cursor 20 is directed in a longitudinal direction A, the nodules 03 of each of the parts 01 and 02 are pressed sequentially through the respective receptor opening portions 13, and then fully pressed into the corresponding receptors 06 such that the nodules 03 elastically expand. When the cursor 20 is directed in an opposite longitudinal direction B, each of the parts 01 and 02 is separated in turn by the separator bar 23.

[Patent Literature 1] US2021/0267321A1

In the cursor 20 described in the above-described Patent Literature 1, the dimensions in the front-rear direction increase from the exit chamber 26 toward the entrance chamber 21 in the longitudinal direction. Here, a front blade (the upper blade in FIG. 4A) of a cursor 40 guiding the part 01 is inclined toward the front side as approaching the entrance chamber 21, and a rear blade (the lower blade in FIG. 4A) of the cursor 40 guiding the part 02 is inclined toward the rear side as approaching the entrance chamber 21. In such a configuration, when the part 01 on the front side and the part 02 on the rear side engage with each other, both of the parts 01 and 02 must be bent in the front-rear direction and have high bending resistance, and thus the sliding resistance of the cursor 40 increases.

The present invention has been made in consideration of the above problems, and the object thereof is to provide a slide fastener capable of reducing the sliding resistance of the slider.

SUMMARY

[1] A slide fastener including:

• • a pair of left and right first fastener tape and second fastener tape which are elongated in an up-down direction;
  • a first element row provided at one end portion of the first fastener tape in a left-right direction;
  • a second element row provided at one end portion of the second fastener tape in the left-right direction and facing the first element row; and
  • a slider disposed to be slidable in the up-down direction, the slider configured to engage the first element row with the second element row by sliding upward and configured to separate the first element row and the second element row by sliding downward, in which
  • the slider includes
    • a first blade configured to guide the first element row, and
    • a second blade that faces the first blade and that is configured to guide the second element row,
  • the first blade extends substantially parallel to the up-down direction,
  • the second blade is inclined in a direction away from the first blade as going upward,
  • the first element row has a plurality of first elements disposed at a predetermined interval in the up-down direction,
  • each of the first elements has a first protrusion portion that protrudes upward,
  • the second element row has a plurality of second elements disposed at a predetermined interval in the up-down direction, and
  • each of the second elements has a second protrusion portion that protrudes downward and that is configured to engage with the first protrusion portion.

[2] The slide fastener according to [1], in which the slider is provided with a pull tab on the first blade.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a first embodiment of a slide fastener according to the present invention.

FIG. 2 is a perspective view of a first fastener stringer.

FIG. 3 is a cross-sectional view of the slide fastener in a direction substantially perpendicular to a left-right direction.

FIG. 4 is a cross-sectional view of a slide fastener in a first comparative example.

FIG. 5 is a cross-sectional view of a slide fastener in a second comparative example.

FIG. 6 is a cross-sectional view of a slide fastener in a third comparative example.

FIG. 7 is a cross-sectional view of a slide fastener in a fourth comparative example.

FIG. 8 is a graph illustrating sliding resistance with respect to a sliding distance of a slider in the slide fasteners according to the present embodiment and second to fourth comparative examples.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a slide fastener according to an embodiment of the present invention will be described in detail with reference to the drawings.

In this specification, the term “up-down direction” in relation to a slide fastener refers to the sliding direction of a slider, which refers to the longitudinal direction of the slide fastener, and in particular, the direction in which the slider slides to engage left and right element rows with each other is referred to as “upward”, and the direction in which the slider slides to separate the left and right element rows is referred to as “downward”.

Furthermore, the “left-right direction” of the slide fastener refers to the direction in which a pair of element rows are arranged, that is, the direction perpendicular to the sliding direction of the slider, and can also be rephrased as the width direction of the slide fastener.

Furthermore, the “front-rear direction” of the slide fastener is a direction perpendicular to the up-down direction and the left-right direction, and can also be rephrased as the thickness direction of a fastener tape or the height direction of the element row. In the drawings, the side of a rear blade 43 to which a pull tab attachment portion 42 described later is attached is described as the “rear”, but this is not intended to limit the “front-rear direction” in actual usage situations, and when a slide fastener 1 is attached to clothing or the like and used, the side of the rear blade 43 to which the pull tab attachment portion 42 is attached becomes the so-called “front side (outer side)”.

FIG. 1 is a perspective view of a first embodiment of a slide fastener according to this invention. As illustrated in FIG. 1, the slide fastener 1 of the present embodiment includes a pair of left and right first and second fastener stringers 3 and 5, and a slider 40 capable of opening and closing the pair of left and right first and second fastener stringers 3 and 5. As will be described later, the slider 40 engages a first element row 50 with a second element row 60 by sliding upward, and separates the first element row 50 and the second element row 60 by sliding downward.

FIG. 2 is a perspective view of the first fastener stringer. In addition, since the second fastener stringer 5 has a shape that is substantially point-symmetric with the first fastener stringer 3 rotated 180 degrees about an axis along the up-down direction, except for the protruding direction of a first element 53 and a second element 63 in the up-down direction, a perspective view of the second fastener stringer 5 is omitted. As illustrated in FIGS. 1 and 2, the pair of left and right first and second fastener stringers 3 and 5 are elongated in the up-down direction and include a pair of left and right first and second fastener tapes 10 and 20 each having rear surfaces 11 and 21 and front surfaces 13 and 23 opposite to the rear surfaces 11 and 21, the first element row 50 provided at one end portion (the right end portion in FIG. 1) of the first fastener tape 10 in the left-right direction, and the second element row 60 provided at one end portion (the left end portion in FIG. 1) of the second fastener tape 20 in the left-right direction. In the left-right direction of the first fastener tape 10 and the second fastener tape 20, the side on which the first and second element rows 50 and 60 are provided is defined as one end side in the left-right direction, and the other side is defined as the other end side in the left-right direction.

The first and second fastener tapes 10 and 20 are, for example, woven or knitted fabrics made of polyester yarn or the like, and have excellent pliancy. The material of the first and second fastener tapes 10 and 20 is not particularly limited, and may be resin or nonwoven fabric.

FIG. 3 is a cross-sectional view of the slide fastener in a direction substantially perpendicular to a left-right direction. As illustrated in FIGS. 1 to 3, each of the first and second element rows 50 and 60 may have respective first and second bases 51 and 61, and the first and second bases 51 and 61 may include a respective front surface and a rear surface opposite to the front surface. The front surface of the first base 51 and the rear surface of the second base 61 are positioned to face each other in the front-rear direction.

The first element row 50 includes a plurality of first elements 53 and 53 extending from the front surface of the first base 51 toward the front surface side. The second element row 60 includes a plurality of second elements 63 and 63 extending from the rear surface of the second base 61 toward the rear surface side. Each of the plurality of first and second elements 53 and 63 is disposed at predetermined intervals in the up-down direction. In the illustrated example, four rows of a plurality of first and second elements 53 and 63 disposed along the up-down direction are provided in each of the left-right directions.

Each pair of first and second elements 53 and 63 adjacent to each other in the up-down direction is provided with an element pitch distance P therebetween. Each pair of first and second elements 53 and 63 adjacent to each other in the up-down direction defines first and second engagement gaps 52 and 62 therebetween. The second element row 60 is configured to be fastened to the first element row 50 when the rear surface of the second element row 60 faces and approaches the front surface of the first element row 50. The plurality of first engagement gaps 52 and 52 of the first element row 50 are sized to accommodate the plurality of second elements 63 and 63 of the second element row 60 in a freely engageable manner. In addition, the plurality of second engagement gaps 62 and 62 of the second element row 60 are sized to accommodate the plurality of first elements 53 and 53 of the first element row 50 in a freely engageable manner. The assembled thickness T of the first and second element rows 50 and 60 assembled together is illustrated in FIG. 3.

A plurality of first and second clearance grooves 54 and 64 are formed on the rear surface of the first base 51 of the first element row 50 and on the front surface of the second base 61 of the second element row 60. The first clearance groove 54 is recessed toward the front side, and the second clearance groove 64 is recessed toward the rear side. The first and second clearance grooves 54 and 64 each extend across the first and second bases 51 and 61 to penetrate therethrough in the left-right direction. The plurality of first and second clearance grooves 54 and 64 are formed at positions substantially aligned with the first and second elements 53 and 63 in the up-down direction. When “substantially aligned”, at least a part of each of the first and second clearance grooves 54 and 64 overlaps with the first and second elements 53 and 63 in the up-down direction. More preferably, the center of each of the first and second clearance grooves 54 and 64 coincide with the center of each of the first and second elements 53 and 63 in the up-down direction. By providing such first and second clearance grooves 54 and 64, the first and second element rows 50 and 60 are allowed to bend.

As illustrated in the drawing, the first base 51 and the plurality of first elements 53 and 53 can be integrally formed with each other. Similarly, the second base 61 and the plurality of second elements 63 and 63 can be formed integrally with each other. Furthermore, the first element row 50 including the first base 51 and the plurality of first elements 53 and 53, and the first fastener tape 10 can be formed integrally. Similarly, the second element row 60 including the second base 61 and the plurality of second elements 63 and 63, and the second fastener tape 20 can be formed integrally. In a modified embodiment, the first and second element rows 50 and 60 may be formed separately from the first and second fastener tapes 10 and 20, and the separate first and second element rows 50 and 60 may be connected to the first and second fastener tapes 10 and 20.

As illustrated in FIG. 2, the first fastener stringer 3 may define a first center line 55 that is perpendicular to the front-rear direction and passes through the center between the rear surface 11 and the front surface 13 of the first fastener tape 10. Similarly, although not illustrated, the second fastener stringer 5 may define a second center line that is perpendicular to the front-rear direction and passes through the center between the rear surface 21 and the front surface 23 of the second fastener tape 20. In the present embodiment, the first fastener stringer 3 and the second fastener stringer 5 are substantially point-symmetric except for the protruding direction of the first element 53 and the second element 63 in the up-down direction, and thus it can be said that the first fastener stringer 3 in FIG. 2 illustrates an outline of the second fastener stringer 5.

Furthermore, each of the first and second element rows 50 and 60 includes: first and second inner walls 56a and 66a connecting the first and second bases 51 and 61 to the first and second fastener tapes 10 and 20; first and second outer walls 56b and 66b distal from the first and second inner walls 56a and 66a; and first and second intermediate walls 56c and 66c positioned between the first and second inner walls 56a and 66a and the first and second outer walls 56b and 66b. In other words, the first and second outer walls 56b and 66b, the first and second intermediate walls 56c and 66c, and the first and second inner walls 56a and 66a are provided at one end portion in the left-right direction, the intermediate portion in the left-right direction, and the other end portion in the left-right direction of the first and second bases 51 and 61, respectively.

In the illustrated example, the first and second fastener tapes 10 and 20 are connected to a tip end portion (front end portion) of the first inner wall 56a and a tip end portion (rear end portion) of the second inner wall 66a. The first and second bases 51 and 61 are connected to the base end portion (rear end portion) of the first inner wall 56a and the base end portion (front end portion) of the second inner wall 66a. Therefore, the first base 51 is positioned on the rear side of the first fastener tape 10, and the second base 61 is positioned on the front side of the second fastener tape 20.

As illustrated in FIG. 2, the first intermediate wall 56c may have a length that extends forward from the first base 51 and terminates at the first center line 55. In addition, the second intermediate wall 66c may have a length that extends rearward from the second base 61 and terminates at the second center line (not illustrated). In this case, when the first and second element rows 50 and 60 are engaged with each other, the first intermediate wall 56c and the second intermediate wall 66c come into contact with each other in the front-rear direction or face each other with a small gap therebetween in the front-rear direction.

In addition, the first intermediate wall 56c may be shorter than the length that terminates at the first center line 55, and the second intermediate wall 66c may be shorter than the length that terminates at the second center line (not illustrated). In this case, when the first and second element rows 50 and 60 are engaged with each other, the first intermediate wall 56c and the second intermediate wall 66c face each other with a gap therebetween in the front-rear direction.

The presence of these walls (the first and second inner walls 56a and 66a, the first and second outer walls 56b and 66b, and the first and second intermediate walls 56c and 66c) improves the strength of the first and second fastener stringers 3 and 5 in the left-right direction. In other words, even when a load is applied in the left-right direction, the possibility of the engagement between the first and second fastener stringers 3 and 5 being unintentionally released is reduced.

As illustrated in FIGS. 1 and 2, the first element row 50 includes four rows of the plurality of first elements 53 and 53 along the vertical direction. The four rows of the first elements 53 are referred to as a first row 53A, a second row 53B, a third row 53C, and a fourth row 53D, in order from the first inner wall 56a side (the other end side in the left-right direction) to the first outer wall 56b side (one end side in the left-right direction). The first row 53A and the second row 53B are disposed between the first inner wall 56a and the first intermediate wall 56c, and the other two rows are disposed between the first outer wall 56b and the first intermediate wall 56c.

The first elements 53 in each of the first to fourth rows 53A to 53D are positioned at substantially the same position in the up-down direction. Therefore, the first elements 53 in each of the first to fourth rows 53A to 53D are disposed adjacent to each other in the left-right direction. A gap in the left-right direction exists between the first element 53 in the first row 53A and the first element 53 in the second row 53B. Similarly, a gap in the left-right direction exists between the first element 53 in the third row 53C and the first element 53 in the fourth row 53D. The presence of the above-described walls (the first inner wall 56a, the first outer wall 56b, and the first intermediate wall 56c) can limit the movement of the second element row 60 with respect to the first element row 50, while the above-described gap in the left-right direction reduces the need for precise alignment of the first element row 50 and the second element row 60 in the left-right direction.

A gap in the left-right direction also exists between the first elements 53 in the second row 53B and the first elements 53 in the third row 53C, and the first intermediate wall 56c is disposed in this gap.

As illustrated in FIG. 1, the second element row 60 includes four rows of the plurality of second elements 63 and 63 along the vertical direction. The four rows of the second elements 63 are referred to as a first row 63A, a second row 63B, a third row 63C, and a fourth row 63D, in order from the second inner wall 66a side (the other end side in the left-right direction) to the second outer wall 66b side (one end side in the left-right direction). The first row 63A and the second row 63B are disposed between the second inner wall 66a and the second intermediate wall 66c, and the other two rows are disposed between the second outer wall 66b and the second intermediate wall 66c.

The second elements 63 in each of the first to fourth rows 63A to 63D are positioned at substantially the same position in the up-down direction. Therefore, the second elements 63 in each of the first to fourth rows 63A to 63D are disposed adjacent to each other in the left-right direction. A gap in the left-right direction exists between the second element 63 in the first row 63A and the second element 63 in the second row 63B. Similarly, a gap in the left-right direction exists between the second element 63 in the third row 63C and the second element 63 in the fourth row 63D. The presence of the above-described walls (the second inner wall 66a, the second outer wall 66b, and the second intermediate wall 66c) can limit the movement of the first element row 50 with respect to the second element row 60, while the above-described gap in the left-right direction reduces the need for precise alignment of the first element row 50 and the second element row 60 in the left-right direction.

A gap in the left-right direction also exists between the second elements 63 in the second row 63B and the second elements 63 in the third row 63C, and the second intermediate wall 66c is disposed in this gap.

The first and second elements 53 and 63 may be arranged in any number of rows. In the above embodiment, the first and second elements 53 and 63 are provided in four rows each, but may be provided in one to three rows, or may be provided in five rows or more, for example. By increasing the number of rows, the engagement strength and strength in the left-right direction of the first and second element rows 50 and 60 can be improved.

The first fastener tape 10 and the second fastener tape 20 are disposed substantially on the same plane when the first and second element rows 50 and 60 are engaged with each other. More specifically, the first center line 55 (refer to FIG. 2) of the first fastener tape 10 and the second center line (not illustrated) of the second fastener tape 20 are disposed substantially on the same plane.

As illustrated in FIG. 3, each of the first elements 53 has a first protrusion portion 57 that protrudes upward from the tip end portion (front end portion) thereof. Each second element 63 has a second protrusion portion 67 that protrudes downward from the tip end portion (rear end portion) thereof. The first protrusion portion 57 and the second protrusion portion 67 bulge out in the up-down direction from the first and second base portions 58 and 68 of the first and second elements 53 and 63, and have a hook shape as illustrated in the example. The hook shape of the first protrusion portion 57 and the hook shape of the second protrusion portion 67 are engaged with each other, whereby the first element row 50 and the second element row 60 are engaged with each other. When the first element row 50 and the second element row 60 are engaged with each other, the first protrusion portion 57 is housed in the second engagement gap 62, and the second protrusion portion 67 is housed in the first engagement gap 52.

The slider 40 engages and separates the pair of left and right first and second element rows 50 and 60. As illustrated in FIGS. 1 and 3, the slider 40 includes a body 41, the pull tab attachment portion 42 provided on the rear surface of the slider body 41, and a pull tab (not illustrated) attached to the pull tab attachment portion 42. By moving the slider 40 upward, the pair of left and right first and second element rows 50 and 60 are engaged with each other, and by moving the slider 40 downward, the pair of left and right first and second element rows 50 and 60 separate from each other. The slide fastener 1 may also have a top stop portion and a bottom stop portion (not illustrated). Also, instead of the bottom stop portion, an open part having a retainer pin and a retaining box may be provided.

The slider body 41 of the slider 40 includes: the rear blade 43 as a first blade that guides the first element row 50; a front blade 44 that faces the rear blade 43 in the front-rear direction and serves as a second blade that guides the second element row; a right flange portion 43a extending from the right end portion of the rear blade 43 to the front side; a left flange portion 44a extending from the left end portion of the front blade 44 to the rear side; and a connecting column 45 that connects the upper end portion of the right flange portion 43a and the upper end portion of the left flange portion 44a in the left-right direction.

A gap 49a exists between the tip end portion (rear end portion) of the left flange portion 44a and the rear blade 43 in the front-rear direction. This gap 49a functions as a distance between flanges in which the first fastener tape 10 of the first fastener stringer 3 can slide. A gap 49b exists between the tip end portion (front end portion) of the right flange portion 43a and the front blade 44 in the front-rear direction. This gap 49b functions as a distance between flanges in which the second fastener tape 20 of the second fastener stringer 5 can slide.

As illustrated in FIG. 3, a lower opening 46 is defined at the lower end portion of the slider body 41 between the rear blade 43, the front blade 44, the right flange portion 43a, and the left flange portion 44a. A first upper opening 47 and a second upper opening 48 are provided on the front and rear sides of the connecting column 45 at the upper end portion of the slider body 41. The first upper opening 47 is defined between the rear blade 43, the connecting column 45, the right flange portion 43a, and the left flange portion 44a. The second upper opening 48 is defined between the front blade 44, the connecting column 45, the right flange portion 43a, and the left flange portion 44a.

An element guide path 70 that connects the lower opening 46 to the first and second upper openings 47 and 48 is provided inside the slider body 41. This element guide path 70 has one passage extending from the lower opening 46 to the position of the connecting column 45, and two passages branching off to the front and rear by the connecting column 45 and extending to the first and second upper openings 47 and 48 on the front and rear, and is formed substantially in a Y shape overall.

In the element guide path 70, the first element row 50 is guided by the passage on the rear side, and the second element row 60 is guided by the passage on the front side. For example, when the slider 40 is slid upward, the first and second element rows 50 and 60 are guided from the first and second upper openings 47 and 48 toward the lower opening 46, approaching each other in the front-rear direction and engaging with each other. Conversely, when the slider 40 is slid downward, the first and second element rows 50 and 60 are guided from the lower opening 46 toward the first and second upper openings 47 and 48, and the engaging is released.

Here, the rear blades 43 extend substantially parallel to the up-down direction. The rear blade 43 in the illustrated example has a planar shape that is substantially perpendicular to the front-rear direction. Here, when the rear blade 43 is “substantially parallel to the up-down direction”, the rear blade 43 is substantially parallel to the surface of the slide fastener 1 in a engaged state below the slider 40, that is, substantially parallel to the direction in which the first and second element rows 50 and 60 which are engaged with each other extend. As illustrated in FIG. 3, the rear blade 43 extends substantially parallel to the direction D in which the first and second element rows 50 and 60, which are engaged with each other at the assembly thickness T, extend, and is not inclined in the front-rear direction or the left-right direction with respect to the direction D. In order to match the shape of the rear blade 43, the rear surface 45a of the connecting column 45 is also substantially parallel in the up-down direction. The rear surface of the connecting column 45 in the illustrated example has a flat shape that is substantially perpendicular to the front-rear direction. Therefore, the path on the rear side of the element guide path 70 that guides the first element row 50 is substantially straight. The first element row 50 guided by the rear blade 43 and the connecting column 45 within the element guide path 70 extends substantially parallel to the up-down direction and is not inclined in the front-rear direction or left-right direction with respect to direction D, maintaining a substantially straight shape.

The front blade 44 does not extend substantially parallel to the up-down direction, but is inclined toward the front side away from the rear blade 43 as going upward. That is, the front blade 44 is inclined in the front-rear direction with respect to the direction D. In order to match the shape of the front blade 44, the front surface 45b of the connecting column 45 is also inclined toward the front side away from the rear blade 43 as going upward. Therefore, the path on the front side of the element guide path 70 that guides the second element row 60 becomes an inclined path that is inclined toward the front side as going upward. The second element row 60, which is guided by the front blade 44 and the connecting column 45 within the element guide path 70, is curved toward the front side as going upward.

In this manner, by configuring the shapes of the rear blade 43 and the front blade 44 of the slider 40 as illustrated in FIG. 3, when the first and second element rows 50 and 60 are engaged with each other, the first element row 50 maintains a substantially straight shape and only the second element row 60 is engaged which being bent, thereby reducing the bending resistance of the first and second element rows 50 and 60 as a whole and reducing the sliding resistance of the slider 40.

FIG. 4 is a cross-sectional view of the slide fastener in a first comparative example. In the first comparative example illustrated in FIG. 4, the rear blade 43 and the front blade 44 are inclined in the front-rear direction to move away from each other as going upward. In such a comparative example, when the first and second element rows 50 and 60 are engaged with each other, both the first element row 50 and the second element row 60 need to bend in the front-rear direction, which increases the bending resistance of the first and second element rows 50 and 60 as a whole, and increases the sliding resistance of the slider 40.

In addition, in the present embodiment illustrated in FIG. 3, the first protrusion portion 57 of the first element 53, which maintains a substantially straight shape when engaged, protrudes upward (the direction in which the slider 40 slides when performing engaging), and the second protrusion portion 67 of the second element 63, which curves when engaged, protrudes downward (the direction in which the slider 40 slides when the engaging is released). As a result, compared to the second comparative example described later with reference to FIG. 5, when the first and second protrusion portions 57 and 67 engage with each other, interference between the first protrusion portion 57 and the second protrusion portion 67 can be reduced, and the engaging of the first and second element rows 50 and 60 can be smoother.

FIG. 5 is a cross-sectional view of a slide fastener in a second comparative example. The second comparative example illustrated in FIG. 5 differs from the present embodiment illustrated in FIG. 3 in that the first protrusion portion 57 of the first element 53 protrudes downward and the second protrusion portion 67 of the second element 63 protrudes upward. As is clear from the part indicated by reference sign A in FIG. 5, in such a configuration, since the first protrusion portion 57 and the second protrusion portion 67 engage with each other while strongly interfering with each other, vibration may occur during engaging, potentially causing the user to feel tapping-like vibrations. Furthermore, when the interference force between the first protrusion portion 57 and the second protrusion portion 67 is too strong, problems may occur such as the first protrusion portion 57 and the second protrusion portion 67 not being able to appropriately engage with each other or the sliding resistance of the slider 40 becoming large.

In addition, the slider 40 of the present embodiment illustrated in FIG. 3 is provided with the pull tab attachment portion 42 on the rear blade 43 extending substantially parallel to the up-down direction, and the pull tab is provided on this pull tab attachment portion 42. Therefore, even when the pull tab is pulled to move the slider 40 in the up-down direction, the rotation of the slider 40 can be suppressed, and the sliding resistance of the slider 40 can be reduced.

FIG. 6 is a cross-sectional view of a slide fastener in a third comparative example. The third comparative example illustrated in FIG. 6 differs from the present embodiment illustrated in FIG. 3 in that the pull tab attachment portion 42 is provided on the front blade 44 having an inclined shape. In this third comparative example, when the pull tab is pulled to move the slider 40 in the up-down direction, a force is applied to the slider 40 to rotate it clockwise or counterclockwise on the paper surface of FIG. 6, because the pull tab attachment portion 42 is provided on the inclined front blade 44. This may increase the sliding resistance of the slider 40, making it difficult to achieve smooth sliding.

FIG. 7 is a cross-sectional view of the slide fastener in a fourth comparative example. The fourth comparative example illustrated in FIG. 7 differs from the present embodiment illustrated in FIG. 3 in that the first protrusion portion 57 of the first element 53 protrudes downward, the second protrusion portion 67 of the second element 63 protrudes upward, and a pull tab attachment portion 42 is provided on the front blade 44 having an inclined shape. In the fourth comparative example, since the first protrusion portion 57 and the second protrusion portion 67 engage with each other while strongly interfering with each other, vibration may occur during engaging, potentially causing the user to feel tapping-like vibrations. Furthermore, when the pull tab is pulled to move the slider 40 in the up-down direction, a force is applied to the slider 40 to rotate it clockwise or counterclockwise on the paper surface of FIG. 6, because the pull tab attachment portion 42 is provided on the inclined front blade 44. This may increase the sliding resistance of the slider 40, making it difficult to achieve smooth sliding.

FIG. 8 is a graph illustrating sliding resistance with respect to a sliding distance of the slider in the slide fasteners according to the present embodiment and second to fourth comparative examples. The inventors measured the sliding resistance of the slider 40 when the slider 40 was slid upward for the present embodiment (refer to FIGS. 1 to 3), the second comparative example (refer to FIG. 5), the third comparative example (refer to FIG. 6), and the fourth comparative example (refer to FIG. 7). The measurement results are illustrated in FIG. 8. As illustrated in FIG. 8, it has become clear that the slide fastener 1 of the present embodiment has very low sliding resistance and can achieve smooth engaging, as compared with the second to fourth comparative examples.

This invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of this invention.

In the above embodiment, a so-called vertical-engaging slide fastener has been described in which the first and second element rows 50 and 60 face each other in the front-rear direction and the first and second elements 53 and 63 engage with each other in the front-rear direction. However, this invention is not limited to the above embodiment. For example, the first and second element rows 50 and 60 may face each other in the left-right direction, and the first and second elements 53 and 63 may engage with each other in the left-right direction, forming a so-called lateral-engaging slide fastener. In this case, the slider 40 and the first and second element rows 50 and 60 have a shape rotated by 90° compared to those in the above-described embodiments illustrated in FIGS. 1 to 3. The first blade of the slider 40 that guides the first element row 50 extends substantially parallel with the up-down direction and front-rear direction (extends substantially perpendicularly in the left-right direction), and the second blade of the slider 40 that guides the second element row 60 is inclined in the left-right direction away from the first blade as going upward. Even when this invention is applied to such a lateral-engaging slide fastener, the same effects as those of the above-described embodiment can be achieved.

As described above, this specification discloses the followings.

[1] A slide fastener including:

• • a pair of left and right first fastener tape and second fastener tape which are elongated in an up-down direction;
  • a first element row provided at one end portion of the first fastener tape in a left-right direction;
  • a second element row provided at one end portion of the second fastener tape in the left-right direction and facing the first element row; and
  • a slider disposed to be slidable in the up-down direction, the slider configured to engage the first element row with the second element row by sliding upward and configured to separate the first element row and the second element row by sliding downward, in which
  • the slider includes
    • a first blade configured to guide the first element row, and
    • a second blade that faces the first blade and that is configured to guide the second element row,
  • the first blade extends substantially parallel to the up-down direction,
  • the second blade is inclined in a direction away from the first blade as going upward,
  • the first element row has a plurality of first elements disposed at a predetermined interval in the up-down direction,
  • each of the first elements has a first protrusion portion that protrudes upward,
  • the second element row has a plurality of second elements disposed at a predetermined interval in the up-down direction, and
  • each of the second elements has a second protrusion portion that protrudes downward and that is configured to engage with the first protrusion portion.

According to this configuration, the first blade (43) of the slider that guides the first element row (50) extends parallel in the up-down direction, and the second blade (44) of the slider that guides the second element row (60) is inclined in a direction away from the first blade (43) as going upward. Therefore, when the first and second element rows (50, 60) engage with each other, the first element row (50) maintains a substantially straight shape and only the second element row (60) is engaged while being bent, thereby reducing the bending resistance of the first and second element rows (50, 60) as a whole and reducing the sliding resistance of the slider (40). That is, with the slide fastener of the present invention, the sliding resistance of the slider can be reduced. In addition, since the first protrusion portion (57) of the first element (53) protrudes upward and the second protrusion portion (67) of the second element (63) protrudes downward, the resistance when the first and second protrusion portions (57, 67) engage with each other can be reduced, and the first and second element rows (50, 60) can be smoothly engaged with each other. Conversely, when the first protrusion portion (57) of the first element (53) is configured to protrude rearward and the second protrusion portion (67) of the second element (63) is configured to protrude forward, the first and second protrusion portions (57, 67) will engage with each other while strongly interfering with each other, which may cause problems with the engaging of the first and second element rows (50, 60).

[2] The slide fastener according to [1], in which the slider is provided with a pull tab on the first blade.

According to this configuration, a pull tab is provided on the first blade (43) extending substantially parallel to the up-down direction, and thus even when the pull tab is pulled to move the slider (40) in the up-down direction, rotation of the slider (40) can be suppressed, and the sliding resistance of the slider (40) can be reduced.