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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC § 119 from Japanese Utility Model Application No. 2024-001537 filed on May 16, 2024, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a slider used for a concealed slide fastener in which when left and right element rows are meshed with each other, the meshed element rows are concealed so as not to be seen from a tape outer surface side exposed to the outside of a fastener tape.

BACKGROUND

As a slider used for a concealed slide fastener in the related art, the slider disclosed in Patent Literature 1 or Patent Literature 2 is known.

As illustrated in FIGS. 12 and 13, a slider body 111 for the concealed slide fastener described in Patent Literature 1 includes a lower blade 123, rails 122 erected along side edges of the lower blade 123, left and right flanges 121 extending in a direction in which the left and right flanges 121 approach each other from upper ends of the rails 122, a guide column 116, an attachment column 117 protruding upward from the guide column 116, a lock claw 118 attached to the attachment column 117, a clamper 114 attached to the lock claw 118, and a pull 113 attached to the clamper 114.

Further, as illustrated in FIG. 13, the concealed slide fastener is used in a state in which the slider body 111 for the concealed slide fastener, a pair of right and left fastener tapes 133 sewn to a fabric 131 to which the fastener is attached, and fastener elements 132 sewn to the fastener tapes 133 are included. Each of the fastener tapes 133 includes a pair of right and left tape main portions 134, an element attachment portion 135, and a tape folding portion 136 folded in a U-shape along a tape length direction.

Regarding the slider body 111 for the concealed slide fastener described in Patent Literature 2, FIG. 14 is a perspective view of the slider body 111, and similarly to FIG. 12, includes the lower blade 123, the rails 122 erected along the side edges of the lower blade 123, the left and right flanges 121 extending in the direction in which the left and right flanges 121 approach each other from the upper ends of the rails 122, the guide column 116, the attachment column 117 protruding upward from the guide column 116, the lock claw 118 attached to the attachment column 117, the clamper 114 attached to the lock claw 118, and the pull 113 attached to the clamper 114.

• • Patent Literature 1: JPH10-234429A
  • Patent Literature 2: JP2006-102286A

However, regarding the slider for the concealed slide fastener described in each of Patent Literatures 1 and 2, when the slider is pulled up in a state in which a large lateral pulling force is applied to the fastener tapes (see an operation state in FIG. 15), a contact stress between the flanges of the slider and tape folding portions (portions corresponding to the tape folding portions 136 in FIG. 13) of the fastener tapes becomes large, and an operation feeling that flange tips are caught to the fastener tapes may be generated. In particular, in a case in which a thin fabric, a fabric having rough yarn weaves, or a fabric of a knit tape is used as the fastener tapes in order to achieve weight reduction and improve air permeability of the slide fastener, a phenomenon may occur that the flange tips bite into the fastener tapes and then it is difficult to further pull up the slider.

It is considered that when the flanges 121 further protrude forward than the rails 122 as in the slider illustrated in FIG. 14, this phenomenon is likely to occur due to a size and a protruding shape of protruding portions. Further, repetition of an opening and closing operation in a state in which the contact stress between the flanges and the fastener tapes of such a slider is large may cause the fastener tapes to be easily damaged, for example.

Therefore, the present invention has been made in view of the above circumstances, and provides a slider for a concealed slide fastener that has a reduced contact stress between flanges and fastener tapes of the slider, is more easily pulled up than that in the related art, and prevents flange tips from being caught to or biting into the fastener tapes.

SUMMARY

A slider for a concealed slide fastener according to the present invention is a slider for a concealed slide fastener that 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, in which
  • 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.

Further, in the slider for a concealed slide fastener, in some cases, regarding dimensions W1 and W0 defined below, the ratio of W1/W0 is in a range of 25% to 35%.

• • W0: half the length of the entire width of the slider in the left-right direction
  • W1: the width of the flange inner-front curved portion in the left-right direction

Further, in the slider for a concealed slide fastener, in some cases, a radius of curvature of the flange inner-front curved portion is in a range of 1.2 mm to 2.0 mm.

Further, in the slider for a concealed slide fastener, in some cases, the radius of curvature of the flange inner-front curved portion is larger than a radius of curvature of a flange outer-front curved portion.

Further, in the slider for a concealed slide fastener, in some cases, 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.

Further, in the slider for a concealed slide fastener, in some cases, a length D1 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.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a slider for a concealed slide fastener. (Example)

FIG. 2 is a plan view of the slider for a concealed slide fastener. (Example)

FIG. 3 is a side view of the slider for a concealed slide fastener. (Example)

FIG. 4 is a view of the slider for a concealed slide fastener as viewed from a rear direction. (Example)

FIG. 5 is a view of the slider for a concealed slide fastener as viewed from a front direction. (Example)

FIG. 6 is a cross-sectional view of the slider for a concealed slide fastener. (Example)

FIG. 7 is a diagram that illustrates a position relation among a rail front end portion, a flange front end portion, and a start point of a flange inner-front curved portion in a plan view (a) and a cross-sectional view (b) of the slider for a concealed slide fastener. (Example)

FIG. 8 is a diagram that illustrates a position relation among a rail front end portion, a flange front end portion, and a start point of a flange inner-front curved portion in a plan view (a) and a cross-sectional view (b) of a slider for a concealed slide fastener. (Conventional Example)

FIG. 9 is a plan view in which the example and the conventional example are arranged in a front-rear direction, the example is illustrated on an upper side (a), and the conventional example is illustrated on a lower side (b).

FIG. 10 Each of (a) and (b) of FIG. 10 is a diagram that illustrates a relation between positions of elements and forces acting on the slider in the example.

FIG. 11 Each of (a) and (b) of FIG. 11 is a diagram that illustrates a relation between positions of elements and forces acting on the slider in the conventional example.

FIG. 12 is a perspective view illustrating a use state of the slider for a concealed slide fastener. (Conventional Example)

FIG. 13 is a cross-sectional view of the slider for a concealed slide fastener. (Conventional Example)

FIG. 14 is a perspective view of the slider for a concealed slide fastener. (Conventional Example)

FIG. 15 is a diagram that illustrates a use state of the slider for a concealed slide fastener. (Conventional Example)

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Further, the present invention is not limited to the embodiment described below.

Here, in the description of the present invention, a side from which fastener elements are separated is defined as a front side, a side from which the fastener elements are meshed is defined as a rear side, a sliding direction of a slider is defined as a front-rear direction (a length direction), a direction orthogonal to the front-rear direction and parallel to fastener tapes is defined as a left-right direction (a width direction), and a direction orthogonal to the front-rear direction and the left-right direction is defined as an up-down direction.

A slider for a concealed slide fastener according to the embodiment of the present invention will be described.

FIG. 1 is a perspective view of a body of the slider according to the present embodiment, FIG. 2 is a plan view of the slider body, FIG. 3 is a side view of the slider body, FIG. 4 is a view of the slider body as viewed from a rear direction, and FIG. 5 is a view of the slider body as viewed from a front direction. FIG. 6 is a view of a cross section taken along a line B-B in FIG. 3 as viewed from an arrow direction.

As illustrated in these drawings, a slider body 11 according to the present embodiment includes, as a basic structure, a lower blade 23, a pair of left and right rails (22, 22) erected along side edges of the lower blade 23 in the left-right direction, left and right flanges (21, 21) extending in a direction in which the left and right flanges (21, 21) approach each other from upper ends of the pair of left and right rails (22, 22), a guide column 16 erected from the lower blade 23 between the left and right flanges (21, 21), and attachment columns (17, 18) disposed above the guide column 16. The slider body 11 has a frontward opening 13 and a rearward opening 12, and an element passage 14 is formed between the frontward opening 13 and the rearward opening 12.

The lower blade 23 has a thickness direction in the up-down direction, and has a symmetrical shape in the left and right direction. The shape of the lower blade 23 on the front side (the side of the frontward opening 13 and the left and right sides of the guide column 16) is a substantially elliptical shape elongated in the sliding direction of the slider, a major axis of the substantially elliptical shape is oriented in the front-rear direction of the slider, and a minor axis thereof is oriented in the left-right direction of the slider. Accordingly, on the front side of the lower blade 23, a portion having a rounded shape of the lower blade 23 is largely exposed on the left and right sides of the guide column 16.

Each of the pair of rails (22, 22) is formed of a curved plate-like member having a rail inner surface 43 and a rail outer surface 42, and the rails 22 are erected toward the front direction from a rear end portion of the lower blade 23 along the left and right side edges.

As illustrated in FIG. 1, the guide column 16 is erected from a central portion of the lower blade 23 in the left-right direction near the frontward opening 13 of the slider body 11. Further, as illustrated in FIGS. 2 and 3, the front attachment column 17 and the rear attachment column 18 are provided on an upper surface of the guide column 16. The front attachment column 17 has a substantially rectangular parallelepiped shape. Further, an upper surface portion of the front attachment column 17 is provided with a groove 20 for attaching a spring of a lock claw, which extends in a rectangular shape from a front end portion toward the rear side.

The rear attachment column 18 has a substantially triangular shape with the front side as a bottom side and the rear side as an apex in a plan view. Further, the rear attachment column 18 has a substantially triangular shape that is high on the front side and is low on the rear side in a side view. In the plan view, an insertion hole for a claw portion of the lock claw is provided in a central portion of the triangular shape. A pull attachment recess 19 is formed between the front attachment column 17 and the rear attachment column 18. The lock claw integrated with a plate spring and a pull (or a pull clamper) are attached to the groove 20 for attaching the spring and the pull attachment recess 19 and are fixed by caulking or the like, and then the obtained member is used as the slider for a concealed slide fastener (this point is the same as the technique disclosed in Patent Literature 2).

A substantially concave passage-like space formed by the lower blade 23, the pair of left and right rails (22, 22), and the pair of flanges (21, 21) serves as the element passage 14 through which the fastener elements (not shown) pass.

The pair of flanges (21, 21) are symmetrical in the left and right direction, and are plate-like members having a thickness direction in the up-down direction. The pair of flanges (21, 21) extend inward to face each other from the pair of rails (22, 22) erected along the left and right side edges of the lower blade 23.

As illustrated in FIG. 2, for convenience of description, an edge portion of the flange 21 is described by being divided into a flange rear portion 35, a flange inner surface-rear portion 34, a flange inner-central portion 33, a flange inner-front curved portion 31, and a flange outer-front curved portion 32. Specifically, first, an edge portion on a rearward opening 12 side serves as the flange rear portion 35, the flange inner surface-rear portion 34 continues forward from the flange rear portion 35, and the flange inner-central portion 33 further continues from the flange inner surface-rear portion 34. The flange inner-central portion 33 is a portion extending linearly. The flange inner-front curved portion 31 extends continuously from the flange inner-central portion 33. The flange inner-front curved portion 31 is a portion that extends curvedly toward the outside of the slider body. A boundary point between the flange inner-central portion 33 and the flange inner-front curved portion 31 is referred to as a start point 38 of the flange inner-front curved portion. The start point 38 of the flange inner-front curved portion is an end point of a linear portion of the flange inner-central portion 33, and is a start point of a curve of the flange inner-front curved portion 31. Further, the flange inner-front curved portion 31 reaches a flange front end portion 37, and the flange outer-front curved portion 32 extends further outward from the flange front end portion 37. When the shapes of the flange and the rail are compared and described as described above, the “curve” or the “linear” means a curve line or a straight line with respect to a boundary line formed when the slider body 11 is viewed in a plan view as illustrated in FIG. 2.

The flange inner-central portion 33 has an inclined linear shape extending in the front-rear direction. The flange inner-front curved portion 31 has a substantially arc shape. In order to solve the above problems to be solved by the present invention, it is important to set a radius R of curvature of the flange inner-front curved portion 31 as large as possible and set the entire flange inner-front curved portion 31 to have a gradual curve shape. The flange outer-front curved portion 32 has a substantially arc shape. It is preferable that a radius R of curvature of the flange outer-front curved portion 32 is also set as a radius of curvature as large as possible to form a gradual curve shape.

The flange front end portion 37 serves as a portion of the flange 21 that is the foremost when the slider is viewed in the front-rear direction. The flange 21 has a width in the left-right direction and a thickness in the up-down direction, and in consideration of the width and the thickness, the foremost portion of the flange 21 is defined as the flange front end portion 37. That is, the flange front end portion 37 may be determined as one point, may be determined as a linear portion (a portion which is a straight line connecting the flange inner-front curved portion 31 and the flange outer-front curved portion 32 and is a straight line parallel to the left-right direction of the slider), and may be determined as a planar portion (a planar portion parallel to the left-right direction and the up-down direction of the slider). As illustrated in FIGS. 3 to 5, surfaces of the flange rear portions 35, the flange inner surface-rear portions 34, the flange inner-central portions 33, the flange inner-front curved portions 31, and the flange outer-front curved portions 32 of the pair of flanges (21, 21) are chamfered.

Subsequently, as illustrated in FIG. 6, the pair of rails (22, 22) are erected along the left and right side edges of the lower blade 23. Surfaces of the pair of rails (22, 22) on the inner side of the slider are the rail inner surfaces (43, 43), which are inclined or curved surfaces appropriately designed to guide the elements. Here, for convenience of description, when the slider is viewed in the front-rear direction, a foremost portion of the rail 22 is defined as a rail front end portion 45. The rail 22 has a thickness in the left-right direction and a thickness in the up-down direction, and in consideration of the thicknesses, the foremost portion of the rail 22 is defined as the rail front end portion 45. That is, the rail front end portion 45 may be determined as one point, may be determined as a linear portion (a linear portion parallel to the left-right direction of the slider), and may be determined as a planar portion (a planar portion parallel to the left-right direction and the up-down direction of the slider).

As can be easily understood from FIG. 6, the shape of the lower blade 23 on the front side (the side of the frontward opening 13) in the slider according to the present invention is a substantially elliptical shape elongated in the sliding direction of the slider, the major axis of the substantially elliptical shape is oriented in the front-rear direction of the slider, and the minor axis thereof is oriented in the left-right direction of the slider. In other words, the above can also be expressed as “a length D1 in the front-rear direction of the lower blade 23 existing forward of the rail front end portion 45 is larger than 30% of a length DO in the front-rear direction of the entire slider”. The shape of the lower blade 23 on the front side (the side of the frontward opening 13) in the slider defines a limit at which the rails 22 can be extended when it is desired to extend the rails 22 longer toward the front side, this point will be described later.

Next, a position relation among the rail front end portion 45, the flange front end portion 37, and the start point 38 of the flange inner-front curved portion in the slider will be described with reference to FIGS. 7 and 8. The left side of each of FIGS. 7 and 8 shows a plan view (a) of a slider body 11, and the right side of each of FIGS. 7 and 8 shows a cross-sectional view (b) of the slider body 11. As in the case of FIG. 6, the cross-sectional view (b) is a view of the cross section taken along the line B-B in FIG. 3 as viewed from the arrow direction.

Reference lines Y0 and Y0′ illustrated in FIGS. 7 and 8 are flange rear end portion reference lines Y0 and Y0′, and are straight lines in the left-right direction that pass through rearmost end portions of flange rear portions 35 and 235. Reference lines Y1 and Y1′ are straight lines in the left-right direction that pass through flange front end portions 37 and 237. Reference lines Y2 and Y2′ are straight lines in the left-right direction that pass through start points 38 and 238 of flange inner-front curved portions. Reference lines Y3 and Y3′ are straight lines in the left-right direction that pass through rail front end portions 45 and 245.

(Note that as a method of expressing 7 reference signs, a dash is added to the reference signs in the figure of a conventional example for the lines indicated by the same definitions, and 2 is added to the digit in the hundreds place of the reference signs in the figure of the conventional example for the portions having the same definitions.)

The lengths in the front-rear direction from the flange rear end portion reference lines Y0 and Y0′ to the flange front end portions 37 and 237 (distances between the reference lines Y0 and Y0′ and the reference lines Y1 and Y1′) are set to L1 and L1′, the lengths in the front-rear direction from the flange rear end portion reference lines Y0 and Y0′ to the start points 38 and 238 of the flange inner-front curved portions (distances between the reference lines Y0 and Y0′ and the reference lines Y2 and Y2′) are set to L2 and L2′, and the lengths in the front-rear direction from the reference lines Y0 and Y0′ to the rail front end portions 45 and 245 (distances between the reference lines Y0 and Y0′ and the reference lines Y3 and Y3′) are set to L3 and L3′.

First, in an example of the present invention, the position relation among the rail front end portion 45, the flange front end portion 37, and the start point 38 of the flange inner-front curved portion will be described with reference to FIG. 7. In the slider for a concealed slide fastener according to the embodiment of the present invention illustrated in FIG. 7, the respective values L1 to L3 are determined to satisfy the following Expression (1).

L1>L3>L2  Expression (1)

That is, in the slider for a concealed slide fastener according to the embodiment of the present invention, the flange front end portion 37 is located forward of the rail front end portion 45, and the start point 38 of the flange inner-front curved portion is located behind the rail front end portion 45.

The slider for a concealed slide fastener according to the embodiment of the present invention as described above is still the same as the conventional example in that a part of the flange inner-front curved portion 31 of the flange 21 extends forward from the rail front end portion 45. In order to avoid a phenomenon that flange tips are caught to or bite into the fastener tapes, which is the problem to be solved by the present invention, in the first place, there may be an idea that the flange inner-front curved portion 31 may not extend forward from the rail front end portion 45. However, if the flanges 21 are too short, when the fastener is closed, the fastener tapes become too easy to move in the up-down direction on the side of the frontward opening 13 (a state in which the fastener tapes flap in a front-back direction), and it becomes difficult to properly guide the elements to element meshing positions at the guide column 16. Therefore, the flange 21 itself cannot be made shorter than in the related art (that is, the front side of the flange 21 cannot be made shorter). As another idea, it is also conceivable to extend the rails 22 forward as compared with those in the related art to eliminate extending portions on the front side of the flanges, but such a change cannot be made because there is a limitation due to the shape of the lower blade 23. That is, as illustrated in (b) of FIGS. 7 and 8, in both the present example and the conventional example, the rails 22 have already been extended forward to about the maximum extent, and when the rails 22 are further extended forward, tips of the rails 22 are extended to enter the inner side of the slider in the left-right direction, so that another significant problem occurs that the fastener elements are less likely to enter the inside of the slider on the side of the frontward opening 13 when the fastener is closed.

Under the assumption that there is the above restriction, how to reduce the phenomenon that the flange tips are caught to the fastener tapes is an important technical point for solving the problem, and the technical significance of the solution achieved in the present invention will be described in detail below.

Here, in order to describe the technical significance of the present invention, the conventional example to be compared is described with reference to FIG. 8, and subsequently, a reason why the flange tips bite into the fastener tapes and a countermeasure thereof will be described with reference to FIGS. 10 and 11.

A basic structure according to the conventional example described with reference to FIG. 8 is substantially the same as that of the example except for an improvement point according to the present invention, but when the basic structure according to the conventional example is described anew so as not to cause misunderstanding, the conventional example includes a lower blade, a pair of left and right rails (222, 222) erected along side edges of the lower blade in the left-right direction, left and right flanges (221, 221) extended in a direction in which the left and right flanges (221, 221) approach each other from upper ends of the pair of left and right rails (222, 222), a guide column erected from the lower blade, and an attachment column disposed above the guide column.

Further, for the sake of convenience, as respective portions of the flange 221, a flange inner-front curved portion 231, a flange outer-front curved portion 232, a flange inner-central portion 233, a flange inner surface-rear portion 234, a flange rear portion 235, a flange front end portion 237, the start point 238 of the flange inner-front curved portion, and the rail front end portion 245 are defined based on the same definitions as in the example, and are denoted by the reference signs as in FIG. 8.

The lower blade 23 and the lower blade of the conventional example have the same shape. Further, the guide column 16 and the guide column of the conventional example also have the same shape.

In addition, as a difference between the example and the conventional example, the conventional example is different from the example in that the start point 238 of the flange inner-front curved portion is located forward of the rail front end portion 245. That is, in the conventional example, there is a relation that the length L2′ in the front-rear direction from the reference line Y0′ to the start point 238 of the flange inner-front curved portion is longer than the length L3′ in the front-rear direction from the reference line Y0′ to the rail front end portion 245. That is, an expression L1′>L2′>>L3′ is satisfied.

Next, in order to clarify the technical significance of the present invention, a relation between forces acting on the elements, the slider, and the fastener tape in the example and the conventional example will be described with reference to FIGS. 10 and 11.

Each of FIGS. 10 and 11 is a diagram for illustrating a relation between positions of the elements and the force acting on the slider in a state in which the slider is pulled up in order to close the slide fastener. FIG. 10 is a diagram of the example according to the present invention, and FIG. 11 is a diagram of the conventional example. In FIGS. 10 and 11, reference signs E1 and E2 and reference signs E1′ and E2′ denote the elements, and state diagrams of the reference sign E1 and the reference sign E1′ are schematic diagrams illustrating a state in which the elements are in contact with a guide surface (the rail inner surface 43) of the rail 22 (a state in which the elements are in contact with the rail 22 at the foremost position at which the elements are guided). Further, state diagrams of the reference signs E2 and E2′ are schematic diagrams illustrating a state in which the elements are not in contact with the guide surface (the rail inner surface 43) of the rail 22 (a state immediately before the elements come into contact with the rail inner surface 43 of the rail 22). Since it is difficult to see in (b) of FIG. 11, the element in the state of the reference sign E2′ is not intentionally illustrated. Further, in FIGS. 10 and 11, the force acting on the slide fastener (for example, a lateral pulling force generated in the fastener when the slider is operated in a closing direction) is indicated by an arrow F0. When the element is located at the position of the reference sign E1, a stress that the rail 22 receives from the element E1 is indicated by an arrow F1. Similarly, when the element is located at the position of the reference sign E1, the flange 21 is in contact with a folding portion of the fastener tape (the tape folding portion 136 in FIG. 13 that is described for Patent Literature 1), and thus the flange 21 receives a stress due to this contact, and this force is indicated by an arrow F2. When the element is in contact with the guide surface (the rail inner surface 43) of the rail 22 as at the position of the reference sign E1, the force acting on the slide fastener can also be received by the rail 22 as F1, and thus the force F2 acting on the flange 21 is reduced accordingly. Since the force F2 acting on the flange 21 is also a force acting on the folding portion of the fastener tape, a decrease in F2 means a decrease in a load applied to the fastener tape. On the other hand, when the element is located at the position of the reference sign E2, the force acting on the slide fastener cannot be received by the rail 22 as F1 because the element is not in contact with the guide surface (the rail inner surface 43) of the rail 22, and thus the force acting on the slide fastener is received as the force F2 acting on the flange 21, and therefore, the force acting on the folding portion of the fastener tape is also considered to be increased accordingly. However, in the example, since the start point 38 of the flange inner-front curved portion is located rearward of the rail front end portion 45, when the element is located at the position of the reference sign E2, a portion of the fastener tape in contact with the flange 21 changes to a smooth curve, that is, the “flange inner-front curved portion 31”, the fastener tape has already been guided to the “flange inner-front curved portion 31”, and an advancing direction thereof is greatly changed such that the orientation of the fastener tape extends from the front-rear direction toward the left-right direction. Therefore, since a component force acting between the flange 21 and the folding portion of the fastener tape is reduced, the load acting on the folding portion of the fastener tape is also reduced.

Next, a discussion relating to the above force acting on the fastener tape will be described in the case of the conventional example. In FIG. 11, since the element is in contact with a guide surface (a rail inner surface 243) of the rail 222 when the element is in the state of the reference sign E1′, the force acting on the slide fastener can also be received as F1′ by the rail 222 as in the above example, so that a stress F2′ acting on the flange 221 is reduced accordingly. However, in a configuration of L2′>L3′ as in the conventional example, there is a zone ΔY in which the element is not guided by the rail 222 even before the flange 221 changes to the “flange inner-front curved portion 231”. As illustrated in FIG. 11, the zone ΔY is between the rail front end portion 245 and the start point 238 of the flange inner-front curved portion (between the straight line Y3′ in the left-right direction that passes through the rail front end portion 245 and the straight line Y2′ in the left-right direction that passes through the start point 238 of the flange inner-front curved portion). The element denoted by the reference sign E2′ indicates a state of an element in the zone ΔY. Since the element E2′ is not guided by the rail 222, the lateral pulling force received by the slide fastener cannot be received by the rail 222 at the position of this element, and most of the lateral pulling force must be received by the flange 221. In addition, in the zone ΔY, the flange 221 is not the flange inner-front curved portion 231 but the flange inner-central portion 233. Since the flange inner-central portion 233 is a linear edge portion extending in the front-rear direction rather than the left-right direction of the slider, the component force acting between the flange 221 and the folding portion of the fastener tape is not largely reduced, and the load is largely applied to the folding portion of the fastener tape. The force is indicated by an arrow Fmax in FIG. 11. This Fmax is considered to be comparable to the sum of F1′ and F2′. As described above, in the conventional example, there is a region in which the load acting on the folding portion of the fastener tape becomes extremely large.

As described in the above analysis, the zone ΔY in the conventional example is a flange range (ΔY) in which the folding portion of the fastener tape needs to receive a high load, and thus the zone ΔY is hereinafter referred to as a “high load flange range ΔY”. As described above, in the conventional example, since almost all of the lateral pulling force of the tape is received on the flange side in the high load flange range ΔY, it is considered that a contact stress between the flanges and the fastener tapes increases, and the phenomenon that the flanges are caught to the fastener tapes occurs.

On the other hand, according to FIG. 10, since an expression L3>L2 is satisfied in the example, the flange range (ΔY) is not generated. Further, in the example, since a flange curve is gentle at the position of the element E2 (in a state of being inclined to extend not in the front-rear direction but in the left-right direction), a component force (the component force acting between the flange 21 and the folding portion of the fastener tape) received from the external force F0 is small.

That is, at a time point when the element passes through the rail front end portion 45, almost all of the lateral pulling force is received by the fastener tape, but at that time point, since the tape has already been located at a position at which the R in the intermediate portion of the flange inner-front curved portion 31 is gentle, the contact stress related to the tape becomes small, and thus it is considered that the defect phenomenon as generated in the above conventional example does not occur.

In addition, since the present embodiment further includes other features, it is also possible to include the feature of further alleviating the defect phenomenon occurring in the conventional example, this point will be described below with reference to FIG. 9. FIG. 9 is a view for explaining, regarding the slider for a concealed slide fastener according to the embodiment of the present invention and the conventional example, improvements of the respective portions of the flange that are performed from the viewpoint of designing the length in the left-right direction rather than the length in the front-rear direction.

(a) of FIG. 9 on the upper side is the example, and (b) on the lower side is the conventional example, and the reference signs in FIG. 9 illustrated for comparison of (a) and (b) are as follows.

X0: a center line of the slider body in the width direction (the left-right direction)

X1: a straight line in the front-rear direction that passes through the start point 38 of the flange inner-front curved portion

X1′: a straight line in the front-rear direction that passes through the start point 238 of the flange inner-front curved portion

X2: a straight line in the front-rear direction that passes through the flange front end portion 37

X2′: a straight line in the front-rear direction that passes through the flange front end portion 237

X3: a straight line in the front-rear direction that passes through an end portion of the slider body in the width direction

W0: half the length of the entire width of the slider in the left-right direction (a distance between the straight line X0 and the straight line X3)

W1: the width of the flange inner-front curved portion 31 in the left-right direction (a distance between the straight line X1 and the straight line X2)

W1′: the width of the flange inner-front curved portion 231 in the left-right direction (a distance between the straight line X1′ and the straight line X2′)

As illustrated in FIG. 9, in the embodiment according to the present invention, the width W1 of the flange inner-front curved portion 31 in the left-right direction is designed to be larger than that in the conventional example. Accordingly, it is possible to more gently guide the folding portion of the fastener tape in the concealed slide fastener along the flange inner-front curved portion 31 having the larger radius of curvature. Therefore, even when the slider is operated to close the concealed slide fastener in a state in which the large lateral pulling force is applied to the concealed slide fastener, the force received by the folding portion of the fastener tape from the flange 21 of the slider is alleviated as compared with that in the conventional example. Specifically, the ratio of W1/W0 in the present invention is preferably 25% to 35%. The ratio of W1′/W0 is 22% in the conventional example.

In addition, due to the improvement by the design described above, in the embodiment according to the present invention, the radius of curvature of the flange inner-front curved portion 31 can also be set to be larger than that in the related art. Specifically, the radius of curvature of the flange inner-front curved portion 31 in the embodiment according to the present invention is preferably in a numerical range of 1.2 mm to 2.0 mm. A radius of curvature of the flange inner-front curved portion 231 is R=1.0 mm in the conventional example.

Further, the embodiment according to the present invention also has a feature in that the radius of curvature of the flange inner-front curved portion 31 is larger than the radius of curvature of the flange outer-front curved portion 32. Specifically, the radius of curvature of the flange inner-front curved portion 31 is R=1.5 mm, whereas the radius of curvature of the flange outer-front curved portion 32 is R=0.4 mm.

Accordingly, when the slider according to the embodiment of the present invention is used, the folding portion of the fastener tape in the slide fastener comes into contact with the edge portion of the flange having a gentler curvature, so that the folding portion can slide on a surface of the flange inner-front curved portion 31 in a more smooth manner than that in the related art.

As described above, according to the present invention, it is possible to achieve a concealed slide fastener in which the contact stress between the flange and the fastener tape is reduced as compared to that in the related art, a pulling-up operation is easily performed, and the flange tips are less likely to be caught to or bite into the fastener tapes even when the fastener tape is a thin fabric or a fabric having rough yarn weaves.

The present invention is not limited only to the embodiment disclosed above, and it is also possible to appropriately use techniques recognized by those skilled in the art as techniques substantially the same as the technical matters described in the embodiment of the present invention or techniques having the same effects as the technical matters, to use the techniques as alternative techniques, or to additionally add the techniques.

As described above, as a result of discussing reasons why the flange tips are caught to or bite into the fastener tapes, the present inventors have found that it is possible to reduce the catching to or the biting into the fastener tapes during the pulling-up of the slider by changing the lengths of the rail and the flange or changing the shape of the flange.

That is, a slider for a concealed slide fastener according to the present invention is a slider for a concealed slide fastener that includes

• • a lower blade (23); a pair of left and right rails (22) erected along side edges of the lower blade (23) in a left-right direction; left and right flanges (21) extending in a direction in which the left and right flanges (21) approach each other from upper ends of the pair of left and right rails (22); a guide column (16) erected on the lower blade (23); and an attachment column (17, 18) provided above the guide column (16), in which
  • a front end portion (37) of each of the flanges is located forward with respect to a front end portion (45) of each of the rails, and
  • a start point (38) of a flange inner-front curved portion (31) is located behind the front end portion (45) of each of the rails.

Further, in the slider for a concealed slide fastener, in some cases, regarding dimensions W1 and W0 defined below, the ratio of W1/W0 is in a range of 25% to 35%.

• • W0: half the length of the entire width of the slider in the left-right direction
  • W1: the width of the flange inner-front curved portion (31) in the left-right direction

Further, in the slider for a concealed slide fastener, in some cases, a radius of curvature of the flange inner-front curved portion (31) is in a range of 1.2 mm to 2.0 mm.

Further, in the slider for a concealed slide fastener, in some cases, the radius of curvature of the flange inner-front curved portion (31) is larger than a radius of curvature of a flange outer-front curved portion (32).

Further, in the slider for a concealed slide fastener, in some cases, a shape of the lower blade (23) on a frontward opening (13) 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.

Further, in the slider for a concealed slide fastener, in some cases, a length D1 in a front-rear direction of the lower blade (23) existing forward with respect to the front end portion (45) of each of the rails is larger than 30% of a length DO in the front-rear direction of the entire slider.

According to the present invention, there is provided a slider for a concealed slide fastener that has a reduced contact stress between flanges and fastener tapes, is more easily pulled up, and is less likely to generate an operation feeling that flange tips are caught to or bite into the tapes.

Claims

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 W1 and W0 defined below, the ratio of W1/W0 is in a range of 25% to 35%,

W0: half the length of the entire width of the slider in the left-right direction,

W1: 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 D1 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.