EP2793634B1

EP2793634B1 - Fastener element for a slide fastener, and methods for the manufacture thereof

Info

Publication number: EP2793634B1
Application number: EP11802100.5A
Authority: EP
Inventors: Masamichi YAMAGATA; Hayato Ishii; Futoshi Kozato; Tsutomu Saito
Original assignee: YKK Corp
Current assignee: YKK Corp
Priority date: 2011-12-22
Filing date: 2011-12-22
Publication date: 2015-09-16
Anticipated expiration: 2031-12-22
Also published as: WO2013091712A1; CN104023581A; CN104023581B; EP2793634A1; TW201334728A; TWI483690B

Description

Technical Field

The present invention relates to a fastener element for a slide fastener, and methods for the manufacture thereof.
More specifically, the present invention relates to a fastener element comprising a metal body having a coupling portion and a tape-retaining portion, wherein the tape retaining portion has two essentially parallel, flat, main surfaces and forms two confronting arms, which are adapted to clamp a fastener tape therebetween, said tape-retaining portion being further provided with at least one protrusion wherein said at least one protrusion is provided on an edge portion of at least one of said main surfaces of the tape retaining portion, and said at least one protrusion extends outwardly from one of the main surfaces of the fastener element to a predetermined height, wherein said predetermined height is the highest in the one of said main surfaces of the fastener element.

Background Art

One known way of manufacturing metal fastener elements or teeth is to punch the teeth out of a piece of flat wire. This is usually done in a series of stamps: the stamping provides a particularly flat surface to (at least) one side of the teeth manufactured in this way, and when the teeth are piled together and coated with some special substances, such as lacquer for polishing, the surface tension of the liquid that gathers on the flat surfaces of the teeth may result strong enough to act like a glue and thereby cause the teeth to become stuck together.
A method for manufacturing fastener elements of the initially defined kind, preventing the sticking of the teeth, is disclosed in international published patent application WO2010/089854 A1 .
The method disclosed therein provides for disrupting the flatness of the stamped surface of the metal teeth to ensure that the surface tension of a liquid coating applied thereto does not have the undesired sticking effect. That problem is solved according to that prior method by forming one or more protrusions on at least one flat surface of a fastener element or tooth.

Disclosure of the Invention

Problem to be solved by the invention

The anti-sticking protrusions with which the fastener elements or teeth are to be provided with in accordance with WO2010/089854A1 are however quite difficult to manufacture by the continuous stamping process disclosed therein. As shown in particular in figures 9 and 10 of said prior document, the fastener elements are made by punching out from a wire, using a cutting punch and die arrangement. The said protrusions are to be made in relief in the fastener elements in areas which are completely "surrounded" by the relevant main surface of the element. This, and the comparatively poor plasticity of the metal materials, makes the creation of the protrusions rather difficult.
US2628400 discloses the preamble of independent claim 1.
It is therefore a specific object of the present invention to provide an improved metal fastener element, which can be more easily manufactured, and which allows to reliably prevent that such fastener elements stick to one another during processing.

Solution of the problem

The above and other objects are achieved according to the invention by a fastener element of the initially-defined kind, characterized in that the predetermined height of said at least one protrusion is the highest in the one of the main surfaces of the fastener element.
Forming one or more protrusions on the edges of the main surfaces of the tape-retaining portion can be more easily and reliably achieved in a continuous stamping process.
In a fastener element according to the present invention, the above-mentioned confronting arms can comprise proximal portions having inner edges which join with one another through an intermediate concave junction, and in that case said at least one protrusion extends on at least part of the length of said junction.
In one embodiment, said at least on protrusion extends for the length of said junction, and therebeyond, into proximal portions of the inner edges of said confronting arms.
In a fastener element according to the invention said confronting arms extend along a longitudinal direction thereof, and the ratio between the longitudinal distance from the distal end of the protrusion to a line drawn to join the furthest point of each distal end of said two arms, and the longitudinal distance from the center of the edge of said junction or flexure to that same line is of about 0.6 or more, and is preferably comprised between about 0.6 and 0.7.
In another embodiment the protrusion extends, preferably continuously, along the inner edge of said arms, from the distal end of one arm to the distal end of the other one, and along said junction.
In different embodiments, protrusions extend only on portions of the inner edge of said arms, the edge of said junction having no protrusion(s).
Conveniently, the protrusion(s) has(have) a tapered cross-sectional profile which projects to an extent which progressively decreases away from the edge of the tape-retaining portion of the fastener element.
The height of the or each protrusion in a semi-finished condition of the fastener element can be comprised between 0.04 mm and 0.07 mm. The height of the or each protrusion in the finished condition of a fastener element is conveniently of about 0.02 mm.
The transverse width of the or each protrusion is conveniently of about 0.1 to 0.15 mm.
As anticipated above, the present invention also relates to methods for manufacturing improved fastener elements.
In one embodiment such a method includes punching a band-like metal wire material using a cutting punch and a cutting die.
Another method includes a step of die-casting the fastener elements.

Brief description of the drawings

Further characteristics and advantages of the present invention will become apparent from the following description, provided merely by way of a non-limiting example, with reference to the accompanying drawings wherein:

Figure 1 is a front view of a slide fastener comprising a plurality of fastener elements according to the present invention;
Figure 2 is a perspective view illustrating a fastener element according to a first embodiment of the present invention;
Figure 3 is a top plan view illustrating the fastener element of figure 2 before being clamped onto a fastener tape;
Figure 4 is a view illustrating the fastener element of figure 3 after being clamped onto a fastener tape;
Figure 5 is a perspective view schematically illustrating a cutting punch and a cutting die through which a fastener element according to the invention is punched from a rectangular wire material;
Figures 6 and 7 are partial cross-sectional views, schematically illustrating process steps by which a fastener element is punched from a rectangular wire material;
Figure 8 is a side elevational view illustrating a fastener element according to the present invention;
Figure 9 is a top plan view for explaining a relationship between two dimensions of a fastener element according to the present invention;
Figure 10 is a perspective view schematically illustrating another embodiment of a fastener element according to the present invention;
Figure 11 is a side elevational view of the fastener element shown in figure 10;
Figure 12 is a top plan view, illustrating another fastener element according to the present invention before being clamped onto a fastener tape;
Figure 13 is a view showing the fastener element of figure 12 after being clamped onto a fastener tape;
Figure 14 is a top plan view illustrating a still further fastener according to the present invention, before being clamped onto a fastener tape;
Figure 15 shows the fastener element of figure 14 after being clamped onto a fastener tape;
Figure 16 is top plan view illustrating another fastener element according to the present invention, before being clamped onto a fastener tape,
Figure 17 shows the fastener element of figure 16, after having been clamped onto a fastener tape; and
Figure 18 is a longitudinal cross-section view of a fastener element according to present invention.

Detailed description of the drawings

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The invention is however not limited to the embodiments described in the following and various changes can be made as long as substantially the same configuration and the same function and effects as the present invention are provided, within the scope of the annexed claims.
In figure 1 there is shown a slide fastener 1 comprising a pair of stringers 3, comprising each a respective flexible tape 2.
The confronting edges of the tapes 2 are provided each with respective pluralities of fastener elements or teeth 10 according to the present invention, which will be later described in greater detail.
The slide fastener 1 in a per se known manner comprises further a slider 4, for engaging and disengaging the fastener elements 10, as well as top end stops 5 and a bottom end stop 6.
With reference to figures 2 and 3, in a first embodiment a fastener element 10 comprises a metal body 11 including a coupling portion 12 and a tape-retaining portion 13.
In that embodiment, the coupling portion 12 includes a coupling concave portion 14, recessed in a first, flat, main surface 20 of the fastener element 10, and a coupling convex portion 15 (see also figures 7 and 8) projecting from a second, opposite, flat, main surface 21 of the fastener element 10.
In other embodiments the coupling portion 12 of the fastener element 10 may have different shapes in particular those which will be described later.
The tape retaining portion 13 forms two confronting arms 16, with distal ends 16a bent one toward the other. The arms 16 each have a flat surface perpendicularly adjoining the main surfaces 20 and 21. Each arm 16 has at least an internal surface facing the other arm and an external surface on the face opposite to that of the internal surface.
As it is readily apparent in figure 2, prior to being clamped onto a fastener tape, the arms 16 of the fastener element 10 extend wide apart along respective and preferably diverging directions.
Said arms 16 have respective proximal portions with inner edges 16b (see figures 3 and 4) which join with one another through an intermediate junction 17.
The junction 17 may have one of many possible configurations, for instance may be curved and concave, or essentially rectangular, or arrow-shaped, etc. and is formed between the arms 16. Said junction 17 has a flat internal surface 17a which lies between the internal surfaces of each of the arms 16 and perpendicularly adjoins the main surfaces 20 and 21.
The surfaces of junction 17 and arms 16 are continuous and form an internal surface perpendicularly adjoining the main surfaces 20 and 21.
As anticipated above, in a fastener element according to the present invention at least one anti-sticking protrusion is provided on an edge portion of at least one of the main surfaces of the tape-retaining portion.
In the embodiment described with reference to figures 2 to 8 a protrusion 30 extends on the edge of the junction 17, for the entire length thereof, and also beyond the junction 17, into proximal portions 16b of the inner edges of the arms 16. The protrusion 30 is formed on the edge of the main surface 20 where it adjoins the internal surface 17a of the junction 17.
Referring to figure 9, in the embodiment which has been disclosed in connection with figures 2-8 the ratio between the longitudinal distance B from the distal ends of the protrusion 30 to a line 1 drawn to join the furthest point of each distal 16a of the arms 16, and the longitudinal distance A from the center of the edge of the junction 17 to that same line 1 is about 0.6 or more, and is preferably comprised between about 0.6 and 0.7.
When the B/A ratio is less than 0.6 the flat area of the main surfaces becomes comparatively larger and the prevention of sticking is consequently more difficult.
However if said ratio is over 0.7 the protrusions 30 may interfere with the attachment of the fastener elements to the edge of a fastener tape, which is generally provided with a cord, such as that indicated C in figure 4.
The fastener element 10 disclosed above in connection with figures 2 to 8 and 9 can be conveniently manufactured by punching a rectangular wire material, such as that indicated 31 in figures 5 to 7.
Referring in particular to figure 5, the wire material 31 is punched from the upper surface side by a cutting punch 32 and a cutting die 33. As it is readily apparent from figures 6 and 7, the protrusion 30 is configured and shaped by a recess 35 predisposed in the cutting punch 32, and cut to the desired profile through the cooperation of the cutting punch 32 with the cutting die 33.
Figure 6 shows the cutting punch 32, the cutting die 33 and the band-like metal wire 31 in the condition immediately prior to the commencement of the stamping process.
Figure 7 shows the fastener element 10 in the state immediately after it has been formed by the stamping process. The protrusion 30 thereof is formed in the process that takes place between the condition shown in figure 6 and the condition shown in figure 7.
The recess 35 provided in the cutting punch 32 (figure 6) enables to form the protrusion 30 by plastic local deformation of the metal material. Said recess 35 is formed at the edge of the cutting surface of the punch 32.
When such a cutting punch 32 is moved in the direction of the cutting die 31, and a fastener element is made from the band-like metal wire 31, the upward action of the die and the downward action of the punch cause part of the band-like metal wire 31 to enter into the recess 35 and form the protrusion 30. Because the recess 35 is formed at the boundary edge of the punch and die, the force exerted by the die more easily affects the area of the band-like metal wire 21 at the recess 35, making it easier to create a protrusion than that proposed in the initially disclosed prior art.
In the embodiment shown in figure 8 (but also in that shown in figure 10), where at the junction 18 there is no protrusion on the second main surface 21, the corners of the second main surface 21 can be curved. However the stamping on the first main surface 20, wherein the protrusion 30 has been formed, has the effect of making the corners of the first main surface 20 pointed.
The fastener elements 10 according to the present invention are made of metal, for instance a copper alloy, a nickel alloy, and aluminum, or the like.
Figures 10 and 11 show another embodiment of a fastener element according to the present invention, which differs from the embodiment described hereinbefore only as far as the coupling portion 12 thereof is concerned.
The structure and the mode of operation of the coupling portion 12 of the fastener element 10 of figures 10 and 11 are known per se, for instance from international published patent application WO2010/089854A1 , which has been already previously cited
The fastener 10 according to figures 10 and 11 includes a coupling head 18 (that may be referred to simply as "coupling head") having coupling convex portions 19 and a tape-sandwiching portion 13 that extends from a base end portion (a rear end portion) of the coupling head 18 through a step surface 40. The fastener element 10 is configured as a so-called double-side element in which the coupling convex portions 19 are disposed on the upper surface side and the lower surface side of the coupling head 18, respectively.
In this case, the upper element surface of the fastener element 10 is a first element surface that abuts on a leading end surface of the cutting punch 32 when punched from the rectangular wire material 31, and the lower element surface is a second element surface which is opposite to it.
The coupling head 18 includes a thin walled flat plate portion 18a disposed at a central portion in the front-back direction, the coupling convex portions 19 that are projectingly disposed on the upper surface and the lower surface of the flat plate portion 18a, and left and right rising portions 41 that are raised from the flat plate portion 18a in the vertical direction and extend toward the left and right sides of the coupling convex portion 19 from the tape-sandwiching portion 13. Further, a coupling concave portion 22 surrounded by the coupling convex portion 19, the left and right rising portions 41, and the tape-sandwiching portion 13 are formed in the coupling head 18.
The flat plate portion 18a of the coupling head 18 is formed at a predetermined thickness thinner than the tape-sandwiching portion 13, and left and right side edges of the flat plate portion 18a are formed to have a circular arc shape or a tapered shape when viewed in the element vertical direction so that a dimension of the left-right width direction of the flat plate portion 18a gradually decreases toward a front end from a base end side.
The coupling convex portion 19 is projectingly disposed to bulge in a protruding shape at a left-right central portion of the flat plate portion 18a. A height position (a position in the vertical direction) of the top of the coupling convex portion 19, that is, a height dimension in the vertical direction, from the upper and lower surfaces of the flat plate portion 18a to the top of the coupling convex portion 19, are set be equal to or larger than a height dimension in the vertical direction, from the upper and lower surfaces of the flat plate portion 18a to upper and lower surfaces of the tape-sandwiching portion 13 (particularly, a body portion 42 of the tape-sandwiching portion 13 which will be described later), respectively.
Further, when the fastener element 10 of the embodiment according to figures 10 and 11 is viewed in the element length direction, the position of the front end edge of the coupling convex portion 19 is set behind the position of a front end edge of the flat plate portion 18a, and the upper surface of the flat plate portion 18a is disposed between the front end edge of the coupling convex portion 19 and the front end edge of the flat plate portion 18a.
The rising portion 41 is formed to rise from the flat plate portion 18a in the vertical direction. It includes an extension portion 41a that extends forward from the tape-sandwiching portion 13 and has a constant thickness, and an inclined portion 41b that is inclined downward toward the front side from the front end of the extension portion 41a. In this case, the front end edge of the rising portion 41 is disposed to be positioned ahead of the rear end edge of the coupling convex portion 19.
In the fastener element 10 of figures 10 and 11 the tape-sandwiching portion 13 includes a body portion 42 that extends backward from the coupling head 18 and a pair of left and right leg portions 16 that branch off to the left and right, respectively and extend from the body portion 42.
The body portion 42 in the tape-sandwiching portion 13 connects the coupling head 18 with the left and right leg portions 16. The upper and lower surfaces and the left and right side surfaces of the body portion 42 are respectively flush with the upper and lower surfaces and the left and right side surfaces of the extension portion 41a of the rising portion 41 and the leg portions 16.
The leg portions 16 are provided in a manner of branching off from a rear end of the body portion 42 into two legs and extending from the rear end.
The tape retaining portion 13 of the fastener element 10 of figures 10 and 11 essentially corresponds to that of the embodiment according to figures 2-9.
In the embodiment shown in figures 12 and 13 the tape retaining portion 13 is provided, on at least one main surface 20, with a protrusion 30 which extends continuously along the inner edge of the arms 16, from the distal end of one arm to the distal arm of the other one, as well as along the intermediate junction 17.
Although in the embodiments described so far the protrusion 30 provided on (at least) one main surface 20 of the fastener element extends continuously, i.e. in one piece, along one edge of the tape-retaining portion, in further embodiments (which have not been represented in the drawings) such a protrusion may comprise a plurality of separate, spaced apart, protrusion portions.
In still further embodiments, shown in figures 14 and 15, the edges of the arms 16 are provided each with respective protrusion portions 30, whereas the edge of said intermediate junction 17 has no protrusions.
In the embodiment shown in figures 16 and 17 the edges of the arms 16 have no protrusions, whereas the edge of the intermediate junction 17, which is the continuous integral inner surface between said arms, is provided with a protrusion 30.
Conveniently, as shown in figure 18, the or each protrusion 30 of a fastener element 10 according to the present invention has a tapered cross-sectional profile, which protrudes to an extent which progressively decreases away from the edge of the tape-retaining portion 13. This is clearly shown in figure 18, in connection with a portion 30a of the cross-sectional profile of the protrusion 30 shown therein. The non-tapered profile portion of the or each protrusion 30 is continuously formed with the internal surface of the junction 17.
As anticipated in the introduction of the description, the height (i.e. the extent of projection) of the or each protrusion in a semi-finished condition of a fastener element 10 is conveniently comprised between 0.04 mm and 0.07 mm, whereas in the finished condition of the fastener element it is of about 0.02 mm.
By remaining between the ranges described above it is possible to ensure that the protrusions do not stand out on the finished product and offer minimum interference in the zipper manufacturing process and daily use of the zipper whilst ensuring effective protection against sticking.
The transverse width of the or each protrusion is about 0.1 to 0.15 mm.
As already mentioned above in connection with figures 5 to 7, fastener elements according to the present invention can be manufactured by a method including punching a band-like metal wire material 31 with a cutting punch 32 and a cutting die 33, wherein the tape retaining portion 13 of the fastener element 10 includes a first surface portion 20, which abuts on the cutting punch 32, and a second surface portion 21, opposite said surface portion 20. The at least one anti-sticking protrusion 30 is disposed on said first surface portion 20.
At least one further anti-sticking protrusion can be formed on said second surface portion 21 of the tape retaining portion 13 of the fastener element.
Alternative methods may include die-casting the fastener elements by forcing molten metal under pressure into a mould cavity having a shape corresponding to that of the fastener elements to be formed. The mould cavity in particular is provided with one or more recesses having a shape corresponding to that of the protrusions to be formed in accordance with the present invention. The fastener elements obtained by die casting are characterized by a pretty good surface finish and dimensional consistency.
Naturally, the principle of the invention remaining the same, various modifications can be envisaged by the persons skilled in this art, without departing from the scope of the invention, as defined in the annexed claims.

Claims

A fastener element (10) for a slide fastener (1), comprising a metal body (11) having a coupling portion (12) and a tape retaining portion (13), wherein the tape retaining portion (13) has two essentially parallel, flat, main surfaces (20, 21) and forms two confronting arms (16), which are adapted to clamp a fastener tape (2) therebetween; the tape retaining portion (13) being provided with at least one protrusion (30), wherein said at least one protrusion (30) is provided on an edge portion of at least one of said main surfaces (20, 21) of the tape retaining portion (13), and said at least one protrusion (30) extends outwardly from one of the main surfaces (20, 21) of the fastener element (10) to a predetermined height, characterized in that said predetermined height is the highest in the one of said main surfaces (20, 21) of the fastener element (10).
The fastener element according to claim 1, wherein a junction (17) of said confronting arms (16) has an internal surface (17a) perpendicularly adjoining said main surfaces (20, 21), and said at least one protrusion (30) is continuously formed with the internal surface (17a) of said junction (17).
The fastener element according to claim 1 or 2, wherein said confronting arms (16) comprising proximal portions having inner surfaces (16b) which join with one another through an intermediate, concave junction (17) having an internal surface (17a); said at least one protrusion (30) being contiguous with the inner surfaces (16b) of the confronting arms (16) and the internal surface (17a) of said junction (17).
The fastener element according to claim 3, wherein said at least one protrusion (30) extends over the length of said junction (17) and therebeyond, into the proximal portions of the inner surfaces (16b) of said arms (16).
The fastener element according to claim 3 or claim 4, wherein said confronting arms (16) extend along a longitudinal direction of the fastener element (10), and a ratio (B/A) between a longitudinal distance (B) from a distal end of the protrusion (30) to a line (1) drawn to join the furthest point of each distal end (16a) of said confronting arms (16), and a longitudinal distance (A) from the center of an edge of said junction (17) to the line (1) is about 0.6 or more, and is preferably comprised between about 0.6 and 0.7.
The fastener element according to claim 3 or claim 4, wherein the protrusion (30) extends, preferably continuously, along the inner surfaces (16b) of said arms (16), from the distal end of one of the arms (16) to the distal end of the other one of the arms (16), as well as along said junction (17).
The fastener element according to any of preceding claims, wherein said protrusion (30) comprises a plurality of separate, spaced protrusion portions (30).
The fastener element according to any of the preceding claims, wherein the protrusion has a tapering surface (30a) extending away from an edge of the tape retaining portion (13) in a direction of the corresponding main surface (20) of the fastener element (10).
The fastener element according to any of the preceding claims, wherein the coupling portion (12) includes a coupling concave portion (14) recessed in a first main surface (20) of the fastener element (10), and a coupling convex portion (15) projecting from a second, opposite, main surface (21) of the fastener element (10).
The fastener element according to any of claims 1 to 7, wherein the coupling portion (12) includes a thin walled flat plate portion (18) and coupling convex portions (19) which project from first and second surfaces of the flat plate portion (18).
The fastener element to any of the preceding claims, wherein the height of the protrusion (30) in a semi-finished condition of the fastener element (10) is comprised between 0.04 mm and 0.07 mm.
The fastener element according to any of the preceding claims wherein the height of the protrusion (30) in a finished condition of the fastener element (10) is of about 0.02 mm.
The fastener element according to any of the preceding claims, wherein the transverse width of the protrusion (30) is of about 0.1 to 0.15 mm.
The fastener element according to any of the preceding claims, wherein said at least one protrusion (30) is an anti-sticking protrusion.
A method for manufacturing the fastener element (10) according to any of the preceding claims, including punching a band-like metal wire material (31) using a cutting punch (32) and a cutting die (33), the tape-retaining portion (13) of the fastener element (10) including a first surface portion (20) which abuts on the cutting punch (32), and a second surface portion (21) opposite said first surface portion (20); the at least one protrusion (30) being disposed on said first surface portion (20).
The method of claim 15, wherein the at least one protrusion (30) is further formed on said second surface portion (21) of the tape retaining portion (13) of the fastener element (10).