Slide-fastener stringer half with woven-in coupling element and method of making same

Abstract

A set of parallel primary warp filaments are fed to a weaving location next to a set of parallel secondary filaments with a coupling element fed in between these two sets. The primary filaments shed between the two outer levels of a three-level shed, the coupling element sheds between one of these outer levels and the central level of the shed, and the secondary filaments shed between the other outer level and the central level. A pair of weft filaments are introduced as loops from the side of the shed corresponding to the secondary warp filaments, each waft filament being passed between a respective outer level of the warp and the central level. The free ends of the loops are caught by a picker and either hooked together, or a binding filament is passed through them. In this manner the one weft thread has at its inserting side a bight overlying the coupling element. The primary warp thread immediately adjacent the coupling element is of heavier weight than the other primary filaments as is woven oppositely to the coupling element.

Description

1. FIELD OF THE INVENTION

The present invention relates to a slide-fastener stringer half. More particularly this invention relates to a stringer half having a woven in coupling element and a method of making such a stringer half.

2. BACKGROUND OF THE INVENTION

A slide fastener is customarily formed of a pair of stringer halves each of which comrpises a support tape to whose longitudinal edge is secured a coupling element. A slider can be slid along the two stringer halves to interleave the two coupling elements so as to close the fastener, and can be slid in the other direction so as to separate the two halves.

In one particularly advantageous type of slide fastener, the coupling element is woven into the stringer half and a longitudinally extending flap is formed on the stringer half which customarily underlies this coupling element. In this manner as the fastener is closed, the likelihood that an object, such as an undergarment, can get caught in the fastener is greatly reduced, since the coupling element is not exposed on one side. In addition such a flap is sometimes used over top of the slide fastener coupling element so as to cover this element and make a slide fastener of the so-called invisible type.

One of the principal disadvantages of such a fastener is that it has been found very difficult to join the coupling element securely to the support tape along a longitudinal line inwardly of one of the edges of this tape. In one known embodiment, for example, several warp threads serve to secure the coupling element to the tape. It is also known to simply weave the coupling element right into the support tape, with some of the weft threads overlying the coupling element and securing it to the surface of the tape.

In both such arrangements, and in other arrangements of a similar type, the coupling element is insufficiently strongly secured to the tape. An example of this is in a zipper-type boot or a suitcase having a slide fastener, since the fastener is frequently stressed considerably transversely to the longitudinal direction of the fastener. Thus it is a frequent occurrence in such articles for the slide fastener to be torn apart, with the coupling element being ripped free of its support tape.

3. OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide an improved slide-fastener stringer half.

Another object of this invention is to provide an improved method of making the slide-fastener stringer half.

A further object is to provide a slide-fastener stringer half having an integral coupling element, and a method of making this stringer half so that it overcomes the above-given disadvantages.

4. SUMMARY OF THE INVENTION

These objects are attained according to the present invention in a slide-fastener stringer half formed of a plurality of parallel primary warp filaments which form a primary band and a plurality of secondary warp elements forming a secondary band extending longitudinally alongside the primary band and forming therewith an elongated strip. A continuous synthetic-resin coupling element of the coil or meander type extends longitudinally along the strip between the bands. A first weft filament is woven back and forth across the full width of the band between the warp filaments in customary fashion. A second weft filament is woven back and forth across the primary band only and has at that longitudinal edge of the primary band turned toward the secondary band a plurality of bights which are looped around the coupling element. This second weft filament and the first weft filament both have at the other longitudinal edge of the primary band a plurality of bights which are knitted together.

This arrangement is extremely strong, since the coupling element is secured along its full length by a filament that extends the full width of the support tape to one side of the coupling element, with bights of this filament looped over the coupling element so as to hold it securely and strongly in place. The knitting-together of the two weft elements at the inner edge of the support tape or strips also stabilizes these filaments considerably so that if one of them is broken the entire tape is not likely to fall apart.

In accordance with another feature of this invention that primary warp filament lying directly next to the coupling element is of larger diameter than the other primary warp filament and is woven into the support tape oppositely to the coupling element, so that when the stringer half is woven the thicker primary filament will always be to the opposite side of the shed as the coupling element.

According to another feature of this invention the primary band is further formed with a longitudinally extending filament along its edge opposite to the edge under the coupling element, this filament being knitted through the bights of both the weft filaments along this edge. Thus the support tape has a conventional woven selvage at the edge adapted to be turned toward another such edge of another stringer half, and at its other edge has a knitted selvage.

According to still another feature of this invention this slide-fastener stringer half is made by feeding a plurality of primary warp filaments as a set next to a similar set comprised of a plurality of parallel secondary warp filaments to a weaving location, and feeding an elongated continuous coupling elements between these two sets to the location. Just upstream of the location these sets and the coupling element are periodically divided into a three-level shed. The set of primary warp filaments is shed between the two outer levels of the shed, and the coupling element and the set of secondary warp filaments are each shed only between a respective outer level and the central level. A pair of weft filaments is simultaneously inserted between respective outer levels and the central level. Thereafter the weave is beaten up in the conventional manner. In this arrangement one of the weft filaments extends all the way across the shed when it is pulled tight and the other weft filament extends only as far as the coupling element, as described above. Each weft is fed as a loop through its respective section of the shed, and a picker is provided at the far side of the shed to catch these ends and knit them together as the shed is changed and before the weft is pulled tight.

According to another feature of the method according to the present invention the warp filament at the edge of primary warp filaments toward the set of secondary warp filaments is of substantially heavier weight than the other primary warp filaments and is always shed across from the coupling element. In this manner this heavier thread or filament reinforces the tape and protects the weft filaments securing the coupling element to the tape.

According to yet another feature of this invention the coupling element has a plurality of connecting bights which extend between separate teeth of this coupling element, and a filler cord extends longitudinally through the coupling element. The bights of the second weft filament, that filament securing the coupling element to the tape, are each looped around this filling thread and a respective connecting portion.

5. DESCRIPTION OF THE DRAWING

The above and other objects, features, and advantages of the invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIGS. 1 and 2 are plan partially schematic views of two configurations of slide-fastener coupling stringer halves according to the present invention;

FIG. 3 is a similar view, in larger scale of another configuration in accordance with this invention;

FIG. 4 is a cross section through a stringer as shown in FIG. 3;

FIG. 5 is a top view, partly in section of the arrangement shown in FIG. 4, with some parts removed for clarity;

FIG. 6 is a diagrammatic representation of the shed arrangement for making a stringer half as shown in FIG. 3;

FIG. 7 is a perspective view of a loom for making a half as shown in FIG. 3;

FIG. 8 through 11 are schematic representations indicating the shedding for the configuration of FIG. 3 in more detail; and

FIG. 12 is a view similar to FIG. 3 illustrating another embodiment of this invention.

6. SPECIFIC DESCRIPTION

As shown in FIG. 1 a slide-fastener stringer half 10 comprises a tape C formed by a set of primary warp filaments 11 forming a band 9 and a set of secondary warp filaments 12 forming a band 15 next to and parallel to the band 9. A first weft filament 13 goes back and forth between alternate filaments 11 and 12 from one edge of the tape C to the other.

A coupling element shown schematically at the dot-dash line 14 lies between the two bands 9 and 15, and another weft filament 16, shown here as a thin solid line, extends only across the band 9 and is formed with bights 17 looped over the coupling element 14 and securing it tightly in position. This weft filament 16 runs with the weft filament 13 in the band 9.

The tape C is formed at one of the longitudinal edges A with a knit selvaged edge formed by loops 18 of the filaments 13 and 16 which are hooked into one another by means of a latch needle 21 as is known in the art. The other edge B of the tape C is a simple woven selvage. The weave here being a so-called plain weave, wherein the weft or filling yarns 13 and 16 pass under and over alternate warp yarns 11 and 12.

The stringer half 10' shown in FIG. 2 is identical to that shown in FIG. 1 with like reference numerals being used for like structure. The sole difference here is that the bights 18' in the weft filament 16 are not hooked together but are interconnected by a separate binding thread 19 to form once again a tight, nonraveling selvage A at this edge of the tape C.

In FIG. 3 reference numerals used in FIGS. 1 and 2 are again used for identical structure. Here however at the very edge of the warp set of filaments 11 there is provided a warp filament 68 which is substantially heavier than the other warp filaments 11 In addition six further very fine warp filaments 69 are arranged between this warp filament 68 and the bights 17, four inwardly of the element 14 and two outwardly thereof. These filaments 69 are woven in a three, one, three pattern, that is every other filament runs under the entire tape for three weft filaments, then comes up over one and runs under for three, this being a three-shaft satin type weave. These filaments 69 therefore form a set 70 of three filaments overlying the tape, and a similar set underlying the tape, to protect it from rubbing as the slider goes the length of the coupling element 14. FIGS. 4 and 5 also show how the coupling element 14 has a plurality of heads 14' and connecting portions 72, with a stuffer thread 66 running longitudinally through this element 14. The bights 17 each are pass around the stuffer thread 66 to hold the coupling element 14 very securely in place on the tape.

FIGS. 6 through 11 indicate how a slide-fastener stringer half is woven according to the present invention. The diagrammatic view of FIG. 6 illustrates how the primary warp filaments 11 are subdivided into two groups spread across a major shed F.sub.h between an upper position U.sub.h and a lower position U.sub.t. The sliding filaments 69 are similarly spread across the major shed F.sub.h between an upper position B.sub.h and a lower position B.sub.t, and the reinforcing filament 67 is similarly displaced between an upper position D.sub.h and a lower position D.sub.t. The secondary warp filaments 12 are placed between an upper position R.sub.m lying on a median plane M of the shed F.sub.h and a lower position R.sub.t adjacent the position B.sub.t, D.sub.t, and U.sub.t. The coupling element 14 is displaced between a lower position W.sub.t slightly below the central level M corresponding to position R.sub.m of filament 12 and an upper position W.sub.h slightly above the filaments in positions B.sub.h, D.sub.h and U.sub.h. And inserter 23 serves to insert the filament 16 between the upper level F.sub.1 of the shed F.sub.h and the middle level F.sub.2 of the shed. Another inserter 22 feeds in the yarn 13 between the lower level F.sub.3 of the shed and the central level thereof. These filaments are all woven together at the location indicated by reference numeral 24 in a weaving apparatus indicated by a reference numeral 25.

FIGS. 8 through 11 indicate how the filaments 11 and 67 are alternated back and forth between the shed F.sub.1 and F.sub.3, whereas the coupling element 14 is alternated back and forth the upper level F.sub.1 and the central level F.sub.2 and the warp filaments 12 are only alternated back and forth between the central level F.sub.2 and the lower level F.sub.3. The four filaments 69 are also woven back and forth between the level F.sub.1 and F.sub.3, one up and three down, in a three-shaft satin weave as described above. The positions of the various filaments in the step following FIG. 11 would correspond to FIG. 8, the pattern repeating itself every four threads.

FIG. 7 shows the control arrangement for the inserting needles 22 and 23. The lower needle 22 has an eye 28 through which the filament 13 is threaded. The upper needle 23 has a flag-like blade 30 formed with an eye 29 and a guide edge 31 for the filament 16, this blade 30 being inclined downardly relative to the horizontally oriented loom 25. The two eyes 28 and 29 lie immediately adjacent one another so that the two filaments 13 and 16 lie very close to one another.

A shaft 34 is reciprocated parallel to its longitudinal axis by means of a drive 46 so as to reciprocate the needles in the direction of double-headed arrow G shown in FIG. 7, thereby inserting the two filaments 13 and 16 into the shed. These needles 22 and 23 are secured in a support block 35 attached by a pair of bars 36 and 37 to a block 38 carried on one end of the shaft 34, screws 64 being provided so as to allow the distance between the two blocks 35 and 38 to be varied. In addition to longitudinal reciprocation this shaft 34 is rotated to a limited extent back and forth about its axis by means of a continuously counter-clockwise rotating cam disc 40 formed with a groove 39 in which a follower 41 is received. This follower 41 is connected to another linkage of a variable length 42 and an arm 43 to a yoke 44 on the end of the shaft 34 opposite the block 38. In this manner the needle 23 after passage completely through the shed describes a path as shown at dot-cash line L so that the picker needle 21 can reach through the loops formed thereby, to allow the two yarns 13 and 16 to be pulled tight. A supply 47 of a filament 19 being provided for formation of a tape as shown in FIG. 2.

As shown in FIG. 12 it is also possible to form a slide-fastener stringer half 10" which is made by means of a shuttle, and in which the coupling element 14 is woven in as shown at 13' with alternate filaments.

The arrangement according to the invention forms a slide-fastener stringer half which is extremely durable. This stringer half has in effect an integral flap of fabric which extends transversely to one side of the coupling elements, completely covering and extending beyond this coupling elment so that the chance of catching an undergarment or the like in the fastener as it closed is almost completely eliminated. Furthermore this type of structure is usable to make a so-called invisible slide fastener, in which case the longitudinally extending cover flap overlies the coupling elements.

Claims

We claim:

1. A slide-fastener stringer half comprising:

a plurality of primary parallel warp filaments forming a primary band and a plurality of secondary warp filaments forming a secondary band extending longitudinally alongside said primary band and forming therewith an elongated strip;

a continuous synthetic-resin coupling element extending longitudinally in said strip between said bands;

a first weft filament woven back and forth across the full width of said strip between said warp filaments; and

a second weft filament woven back and forth across said primary band and having at the longitudinal edge of said primary band turned toward said secondary band a plurality of bights looped around said coupling element and having at the opposite longitudinal edge of said primary band a plurality of knitted-together bights.

2. The stringer half defined in claim 1 wherein both of said weft filaments are formed with loops at the longitudinal edge of said primary band opposite said edge having said bights, said loops being interconnected.

3. The stringer half defined in claim 2, further comprising another warp filament extending through said loops.

4. The stringer half defined in claim 3, further comprising at least two supplementary warp filaments between the heavy-weight primary warp filament and said coupling element, said supplementary filaments being woven in a satin weave.

5. The stringer half defined in claim 2 wherein one of said primary warp filaments immediately adjacent said coupling element is of substantially heavier weight than the other primary warp filaments.

6. The stringer half defined in claim 2 wherein said coupling element is formed of a synthetic-resin monofilament having a succession of coupling heads, a succession of connecting portions joining said heads, and a throughrunning filler cord, said bights being looped over said coupling element and said filler cord at said connecting portions.

7. A method of making a slide-fastener stringer half comprising the steps of:

feeding a set of parallel primary warp filaments to a weaving location;

feeding a set of parallel secondary warp filaments next to said set of primary filaments to said location;

feeding an elongated coupling element between said sets to said location;

periodically shedding said primary warp filaments between outer levels of a three-level shed;

periodically shedding said coupling element between one of said outer levels and a central level of said shed;

periodically shedding said secondary warp filaments between the other outer level and said central level; and

periodically simultaneously inserting a respective weft filament between a respective outer level and the central level of said shed.

8. The method defined in claim 7 wherein said weft filaments are inserted as loops into said shed from the side corresponding to said secondary warp filaments, said method further comprising the steps of interconnecting said loops to the side of said shed opposite said secondary filaments.

9. The method defined in claim 8 wherein said loops are interconnected by being hooked together into a knit selvage.

10. The method defined in claim 7 wherein said coupling element is shed in said central level to a position further from said one level than the position of said secondary warp filaments in said central level.

11. The method defined in claim 7 wherein said coupling element is shed into a position in one outer level further from said central level than the position of said primary warp filament in said one outer level.

12. The method defined in claim 7 wherein that primary warp filament closest to said coupling element is of substantially heavier weight than the other primary warp filaments, this heavy-weight primary warp filament being woven oppositely to said coupling element.

13. A method of making a slide-fastener stringer half comprising the steps of:

forming a warp comprising a set of parallel primary warp filaments, a set of parallel secondary warp filaments next to said primary warp filaments, and an elongated coupling element between said sets;

repeatedly inserting a first weft filament across all of said warp filaments;

repeatedly inserting a second weft filament across said primary filaments and said coupling element only; and

looping bights of said second weft filament over said coupling element on each insertion of said second weft filament.