Abstract:
In a method of manufacturing a woven zipper half a woven strip is produced of warp threads and of at least one weft thread. The weft thread is picked in the form of double pick loops. A plastic monofilament is wound to form a row of closing member-forming windings having interlocking heads at one end and winding reversing portions at the other end, wherein the closing member row is positioned on the woven strip. Additional warp threads are positioned underneath the closing member row. During weaving, at least one main knit thread is guided in the upward direction through gaps between the windings to the upper side of the closing member row to form loops with loop heads. The loop heads of the at least one main knit thread at the upper side are interlocked by crocheting. The loop heads, after crocheting, form a mesh structure covering portions of the upper side of the closure member row and interlock the closure member row with the woven strip. Simultaneously to interlocking of the loop heads at the upper side, double pick loops of the loop-shaped main knit thread are formed and the double pick loops are interlaced during weaving with the additional warp threads, and, moreover, the main knit thread is used as a weft thread in the woven strip underneath the closing member row.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This is a continuation of International Application PCT/DE99/01568, with an international filing date of May 28, 1999, now abandoned.  
           [0002]    1. Field of the Invention  
           [0003]    The invention relates to a method for manufacturing a woven zipper half, wherein a woven ribbon is produced of warp threads and of at least one weft thread, wherein the weft thread is picked in the form of double pick loops, wherein a wound closing member row is produced whose member-forming windings have interlocking heads at their one end and winding reversing portions at their other end, wherein the closing member row is positioned on a woven strip, and wherein during weaving at least one knit thread is guided through the gap between the windings upwardly to the upper side of the closing member row and its loop heads are interlocked by crocheting, wherein the crocheted loop heads form a mesh or stitch structure which covers portions of the upper side of the closure member row and connects the closing member row with the woven strip. Accordingly, such a zipper half is comprised, on the one hand, of a closing member row and, on the other hand, of a woven ribbon which are connected to one another in a weaving-technological way. The woven ribbon is woven of warp threads and of at least one weft thread wherein the weft thread is picked in the form of double pick loops. The closing member row is comprised of a wound plastic monofilament thread whose closing member-forming windings have interlocking heads at their one end and winding reversal portions at their other end. During weaving the closing member row is laid on a woven strip.  
           [0004]    2. Description of the Related Art  
           [0005]    The interlocking between the woven strip and the closing member row is realized by a knit thread which during weaving is lifted out of the woven strip in the form of loops and guided through gaps between the windings of the member row to the upper side of the closing member row where its loop heads are then interlocked by crocheting. The crocheted stitch heads form a mesh or knit structure. While the woven strip is positioned at the underside of the closing member row, the knit structure covers the upper side of the closing member row.  
           [0006]    In the known method of this kind (German patent document DE 24 34 978 A) interlacing threads are present in the woven strip produced beneath the closing member row. They form a shed and interlock with a uniform weft extending across the entire width of the woven ribbon. This weft is picked as double pick loops, wherein the picking is carried out from the edge of the woven ribbon which carries the closing member row. Accordingly, at the oppositely positioned edge of the ribbon the projecting loop heads of this double pick must be interlocked by crocheting with one another, for which purpose a separate hook needle is required. Accordingly, a crocheted ribbon edge results which impairs the pleasing appearance of the zipper half. During weaving of the ribbon the sections of the interlacing thread are lifted in loops out of the resulting woven strip and penetrate through the loops between the windings of the closing member row to the upper side. Here, the produced loop of the interlacing thread is interlocked by crocheting with a preceding, already produced loop of another interlacing thread. For this interlocking by crocheting process, a second hook needle is required. Portions of the interlacing thread thus form loop-shaped knit threads. As a result of the woven strip below the closing member row and of the crocheting of the loop heads at the upper side, interlocking of the closing member row with the woven strip results. Not only a catch fork which provides the loop formation but also a second hook needle is required for controlling the interlacing threads during weaving. In order for the catch fork of the correspondingly selected partial piece of a certain interlacing thread to be gripped, a precise control is required. This known method is complex and failure-prone.  
         SUMMARY OF THE INVENTION  
         [0007]    It is an object of the present invention to provide a reliable method of the aforementioned kind in which the product has a clean selvedge without a crocheted edge even though a woven ribbon with double picking has been woven.  
           [0008]    In accordance with the present invention, this is achieved in that underneath the closing member row additional warp threads are positioned and that the loop-shaped knit thread at the same time forms the double pick loops which during weaving are interlaced with the additional warp threads, and the knit thread generates the weft thread in the woven strip underneath the closing member row.  
           [0009]    According to the invention, warp threads are positioned underneath the closing member row which in the finished product are positioned exclusively in the plane of the woven strip that has been produced beneath the closing member row and which are not interlocked by crocheting with one another. In the following these threads will be referred to as “additional warp threads”. The special feature of the invention is that the knit thread forms at the same time the weft thread in the woven strip and interlocks during weaving in the form of double pick loops with the additional warp threads present in the woven strip. When interlocking with the additional warp threads, the double pick loops are guided through the gaps between the windings of the closing member row and their loop heads are interlocked by crocheting on the upper side of the closing member row. This crocheting action of the double pick loops cover portions of the upper side of the closing member row. The double picking of the knit thread produces thus at the oppositely positioned edge of the woven strip a clean, stitch-free selvedge. The produced zipper half has an excellent visual appearance.  
           [0010]    The hook needle for interlocking the double pick loops of the knit thread acting like a weft is the same hook needle which produces the cover of the closing member row at the upper side. In comparison to the prior art, two components have been eliminated, i.e., a catch fork and a second hook needle for the loop ends of the double picks. The picking of the knit thread is realized by the weft needle and this weft needle produces not only the weave interlocking with the additional warp threads in the woven strip beneath the closing member row but also forms at the same time the loops penetrating between the gaps of the windings of the closing member row which are then crocheted with one another at the upper side. In addition to the hook needle, only a single tool is thus required, i.e., the weft needle. This weft needle is not only a weft picking means for the knit thread in the woven strip but also the loop head forming means of the knit thread for the hook needle.  
           [0011]    The interlocking by crocheting of the loop heads generated from the knit thread can be realized by a direct stitch-like interlacing. However, it is further suggested to perform this also indirectly. For this purpose, an auxiliary thread is provided which realizes the stitch-like interlocking. Moreover, such an auxiliary thread, in addition to the stitch formation between the loop heads of the knit thread, can also effect a separate stitch-like interlocking between the closing member row, on the one hand, and the woven strip positioned underneath, on the other hand. With such an additional auxiliary thread the interlocking between the closing member row and the woven strip positioned underneath is improved.  
           [0012]    In most applications, in addition to the woven strip with the closing member row positioned thereon, a wide support ribbon is also desirable which extends as a projecting web adjacent to the closing member row. Such a support ribbon is provided, for example, for attaching the zipper half by sewing on a piece of clothing which is to be provided with a zipper. The excellent appearance of the zipper half according to the invention is improved in that such a support ribbon is comprised of support ribbon warp threads and of a support ribbon weft which itself is picked in the form of double pick loops into the support ribbon warp threads. The support ribbon double pick also produces loop heads which, according to the method of the invention, are arranged in the zone where the loops of the knit thread, picked into the neighboring woven strip, penetrate through the gaps between the windings of the closing member row. The loops of the knit thread secure thus the loop heads of the support ribbon double picks before they are interlocked in a stitch-like mariner with one another at the upper side of the closing member row, as has been mentioned above. Also, at the free edge of the support ribbon a flawless selvedge results because within this selvedge the support ribbon double pick enters the shed which is provided by the support ribbon warp threads. The woven material of this product than has clean selvedges on both sides. This has previously not been possible in the prior art when employing doubled picks.  
           [0013]    With the afore described measures, a hook needle, which would be otherwise required for the stitch formation of the loop heads of the support ribbon double pick loops, can be eliminated at the free selvedge of the support ribbon. The knit thread has a triple function for such a zipper half comprising a support ribbon. The first function is, as mentioned before, that the knit thread as a weft thread produces the woven strip underneath the closing member row. The second function is that the knit thread interlocks the closing member row with the woven strip underneath because it is at the same time the weft thread in this woven strip. The third function of the knit thread is to interlock the support ribbon with the woven strip.  
           [0014]    According to the invention, portions of the closing member row are covered at the underside by the already mentioned woven strip. On the opposite side, the already mentioned stitch-like interlocking of the loop heads of one or more knit threads or auxiliary threads is provided. In addition, or as a supplement thereto, at the upper side of the closing member row additional warp threads can be provided which interlock with such knit threads and thus form a woven material at the upper side which covers the member row even better.  
           [0015]    It is advantageous in the context of the method according to the invention to wind the closing member row during weaving of the woven strip and/or of the support ribbon of a plastic monofilament thread by weaving-technological means. The manufacture of the individual closing members and their aforementioned interlocking is carried out in conformity with the knit threads acting in the woven strip in the manner of a weft thread. The adjusted winding of the closing member row and the interlocking weaving of the individual closing members formed of these windings provides a precise interlocking of the closing member row with the woven strip.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0016]    In the drawing:  
         [0017]    [0017]FIG. 1 is a plan view onto a portion of a woven ribbon with interlocked closing member row illustrating the resulting thread interlocking at the weaving location at the upper edge, wherein the closing members are arranged at a greater spacing relative to one another;  
         [0018]    [0018]FIG. 1 a  is a plan view corresponding to that of FIG. 1 onto the woven ribbon where the closing members are positioned at a smaller spacing relative to one another and the interlocking of the closing member row with the woven material is realized by a knit thread only;  
         [0019]    [0019]FIG. 1 b  is a second alternative to FIG. 1, where, in addition to the knit thread of FIG. 1, a further auxiliary thread interlocks the closing member row with the woven material by means of a second hook needle;  
         [0020]    [0020]FIG. 1 c  is a third alternative to FIG. 1 with an additional auxiliary thread;  
         [0021]    [0021]FIG. 1 d  is a further variant of that shown in FIG. 1, wherein the closing member row is covered at its upper side by special warp threads;  
         [0022]    [0022]FIG. 1 e  is an illustration analog to FIG. 1 of an alternative to the woven ribbon illustrated in FIG. 1, where only the woven strip underneath the closing member row is woven and a support ribbon outside of the closing member row is missing;  
         [0023]    [0023]FIG. 2 is a perspective view of a portion of a needle ribbon weaving machine for manufacturing the zipper half of FIG. 1;  
         [0024]    [0024]FIG. 3 is a further perspective view of the needle ribbon weaving machine according to FIG. 2, with a closing member row being produced;  
         [0025]    [0025]FIG. 4 is a another perspective view of the needle ribbon weaving machine according to FIG. 2, with a closing member row being produced;  
         [0026]    [0026]FIG. 4 a  is a variant of the conditions illustrated in FIG. 4, where, in addition to the knit thread, a second auxiliary thread is supplied by a lifting needle;  
         [0027]    [0027]FIG. 4 b  is a variant of FIG. 4, wherein, at the upper side special warp threads are placed onto the closing member row in order to produce the product according to FIG. 1 d;    
         [0028]    [0028]FIG. 5 a  shows a rear view of a weaving support used in the weaving machine of FIG. 2 and having a cover mounted thereon, wherein the other components of the weaving machine arranged in this area have been omitted;  
         [0029]    [0029]FIG. 5 b  shows a plan view of the weaving support of FIG. 5 a  with mounted cover, wherein the components of the weaving machine arranged in this area have been omitted;  
         [0030]    [0030]FIG. 6 a  shows a cross-section of the weaving machine and a view from the rear onto the weaving reed and the woven ribbon with the closing member row produced downstream thereof, wherein machine components obstructing the view have been omitted; and  
         [0031]    [0031]FIG. 6 b  shows a view from above onto the portion of the weaving machine illustrated in FIG. 6 a  showing the weaving reed in horizontal section.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]    The simplest product  3   e  of the method according to the invention is illustrated in FIG. 1 e.  This zipper half  3   e  is obtained when an actual support ribbon is not required for whatever reasons. In this embodiment, a closing member row  17  is interlocked by means of a main knit thread  4  with a woven strip  38  positioned underneath the closing member row  17  in a weaving-technological way. The knit thread  4  is picked in the form of double picks  12  from the right side into a shed which is formed by warp threads  6   a.  The closing member row  17  is comprised of a plastic monofilament thread  8  which extends in windings and produces thereby closing members  8   c.  The closing member row  17  comprises at its longitudinal edge interlocking heads  8   b  and at the oppositely positioned longitudinal edge rearward arcs  8   a.  Free gaps  21  are positioned between the closing members  8   c.    
         [0033]    During weaving of the zipper half  3   e  according to FIG. 1 e,  the woven strip  38  is produced of the weft or filling threads  12  and the warp threads  6   a  underneath the closing member row  17 , but the loop heads  13  of the double picks  12  are guided through the closing member gaps  21  and are interlocked by crocheting to one another by means of a hook needle  24 . The loop head  13  is guided through the loop interior of the preceding loop head  13 . This forms a mesh or stitch structure  16  at the upper side of the member row  17 .  
         [0034]    The product  3   e  of FIG. 1 e  uses the loop heads  13 , which results at one edge by means of a double pick  12  of the knit thread  4 , in order to interlock as a result of their crochet interlocking with one another the closing member row  17  and the woven strip  38  by weaving. As a result, the oppositely positioned selvedge  11  of this product  3   e  is smooth. The zipper half  3   e  has an attractive appearance.  
         [0035]    The support ribbon in the product  3   e  of FIG. 1 e  can, in principle, be eliminated, and the product  3   e  can be directly worked into a final product. However, when subsequently a support ribbon is desired for this product  3   e,  it is produced in this case separately and then connected to this product  3   e.  However, it is more advantageous when already during the weaving process, which produces the woven strip  38  with the closing member row  17 , the support ribbon is woven together with woven strip  38 . This will be explained in more detail in connection with FIG. 1.  
         [0036]    [0036]FIG. 1 differs from FIG. 1 e  in that in addition to the afore described woven strip  38  with the closing member row  17  the actual support ribbon  1  is formed. The support ribbon  1  is produced of warp threads  6  and a weft thread  2  which is also interlocked in the support ribbon  1  in the form of double picks  25 . The ends of these support ribbon double picks  25  form again loop heads  15 . In this embodiment, they are not interlocked with one another but instead by means of the main knit thread  4  of the woven strip  38 . For this purpose, as illustrated on the selvedge  27  of FIG. 1, the loop head  13  is pulled by the knit thread  4  through the interior of the loop head  15 . By means of the resulting stitch or mesh structure  16  produced from the knit thread loop heads  13 , the support ribbon loop heads  15  are also secured. Accordingly, a clean and smooth selvedge  10  is also formed at the free edge of the support ribbon  1 . As is illustrated in FIG. 4, the main knit thread  4  is formed to a loop by a lifting needle  22 , which serves as a picking means for the weft into the woven strip  38 , and the resulting loop heads  13  are then knitted with one another by means of a hook needle  24  shown also in FIG. 1.  
         [0037]    Instead of the operation illustrated in FIG. 1, where the stitch or mesh structure  16  is produced by the knit thread  4  and in doing so the loop heads of the support ribbon weft thread  12  are engaged, the opposite approach could be taken and the loop heads  15  of the support ribbon weft thread  2  could be knitted together and the loop heads  15  could be guided beforehand through the interior of the loop heads  13  of the main knit thread  4 .  
         [0038]    The zipper half  3   a  illustrated in FIG. 1 a  is designed substantially according to the zipper half  3  illustrated in FIG. 1. The difference is only that the closing members  8   c  in the closing member row  17  are arranged at the same spacing to one another as the double picks  25  of the support ribbon weft  2  and the double picks  12  of the main knit thread  4 . In the zipper half  3  of FIG. 1 the spacing of the closing members  8   c  was twice as large.  
         [0039]    In FIG. 1 b  a further variant of FIG. 1 of a zipper half  3   b  is illustrated. It is characterized by an additional auxiliary thread  9  which reinforces interlocking of the closing member row  17  with the woven strip  38 . In addition to the lifting needle  22  for the main knit thread  4 , already explained in connection with FIG. 1 and FIG. 4, and the hook needle  24  for the knit thread  4 , a second lifting needle  23  is provided which operates between the support ribbon warp threads  6  and the warp threads  6   a.  Moreover, the loop heads resulting from the auxiliary thread  9  are interlocked by crocheting by means of a second hook needle  34 .  
         [0040]    In the embodiment of FIG. 1 c  the zipper half  3   c  has an additional knit thread  5 . As can be seen in FIG. 4 a,  the additional knit thread  5  is also guided by the second lifting needle  23  in the form of a loop between the closing members  8   c  of the closing member row  17 , but, in contrast to FIG. 1 b,  the resulting loop heads are interlocked by the same hook needle  24  which also processes the loop heads  13  of the knit thread  4 . This second lifting needle  23  operates in the area between the support ribbon warp threads  6  and the warp threads  6   a  of the woven strip  38 .  
         [0041]    The zipper half  3   d  illustrated in FIG. 1 d  has basically the same configuration as the zipper half  3  of FIG. 1. The difference is only that in the area of the closing member row  17  special warp threads  7  are used. The special warp threads  7  are also interlocked by the double picks  12  in the woven strip  38  but extend above the windings of the individual closing members  8   c.  The closing member row is additionally covered with these special warp threads  7 . The winding arcs of the plastic monofilament thread  8  in this case are not covered by the mesh or stitch structure  16  but are also covered and secured relative to the woven material or  1  by woven material parts of the warp threads  7  and the double picks  12  of the main knit thread  4 . The closing member row  17  can be pre-manufactured by coil-like or similar windings of the plastic monofilament yarn  8  and can be subsequently interlocked by double picks  12  with the woven fabric or the adjacent support ribbon  2 .  
         [0042]    In FIG. 2, a device for manufacturing the zipper half  3  of FIG. 1 is illustrated. The device is a needle ribbon weaving machine  100  which is illustrated in a simplified form. A weaving phase is illustrated in which the weaving reed  18  is positioned shortly before the stop. The support ribbon weft thread  2  is picked into the shed formed by the warp threads  6  and has been caught by the knit thread  4  interlocking the additional warp threads  6   a.  The knit thread  4  has been received with its loop head in a hook needle  22  and engages behind the still large winding of the plastic monofilament thread  8  for producing the closing members  8   c.  The weaving reed  18  is connected to a return device  18   a  for the monofilament winding. The weaving reed  18  which can be moved in the direction of the double arrow pulls away the large monofilament winding by means of the return device  18   a  and places the plastic monofilament thread  8  about a pin  26  which serves to guide the resulting closing members  8   c.  A loop lifter  19  is provided which is movable in the direction of the illustrated arrows and supports the placement of the monofilament winding. Moreover, a positioning device  20  is provided which is illustrated in its rear position.  
         [0043]    [0043]FIGS. 3 and 4 show the cooperation of some of the machine components of the weaving machine  100  during weaving. With respect to FIG. 2 a different weaving phase is illustrated. The weaving reed  18  is positioned in the rearward area of its stop movement. In FIG. 4, the lifting needle  22  guiding the knit thread  4  has penetrated a shed formed by the warp threads  6   a.  Accordingly, the knit thread  4  has been moved to a reciprocating hook needle  24  which receives the knit thread  4 . A monofilament placement needle  14  for the plastic monofilament thread  8  is provided. This monofilament placement needle  14  is shown in its placement position. With the aid of the upwardly movable loop lifter  19 , the monofilament thread  8  is formed to a winding and placed about the closing member guiding pin  26  when the monofilament placement needle  14  performs a return movement. Simultaneous to the movement of the loop lifter  19 , the positioning device  20  also moves into its rearward position in order to allow winding about the closing member guide pin  26 . The positioning device  20  provides identical spacing of the continuously newly formed closing members  8   c.  Upon return movement of the monofilament placement needle  14  the knit thread  4  engages behind the formed monofilament winding. The picking means  31  for the support ribbon weft thread  2  can be seen in FIGS. 3 and 4.  
         [0044]    In order to ensure a collision-free penetration of the lifting needle  22 , the warp threads  6   a  to be interwoven with the knit thread  4  are guided at an angle of 6° to 10°. The lifting needle  22  is reciprocating at an angle to the shed. The closing member guide pin  26  is floatingly supported The plastic monofilament thread  8  is guided by means of the monofilament placement needle  14  below the pin  26 . After each placement of a monofilament winding the closing member guide pin  26  is returned into the starting position by means of the reciprocating positioning device. On the floating closing member guide pin  26  at least five monofilament windings are present in order to facilitate the weaving action.  
         [0045]    In analogy to the illustration of FIG. 4, FIG. 4 a  shows a variant embodiment  100   a  of the afore described needle ribbon weaving machine. This machine  100   a , as has been mentioned above, serves to produce the zipper half  3   c  illustrated in FIG. 1 c.  In FIG. 4 a  the aforementioned second lifting needle  23  can be seen which is illustrated, as the first lifting needle  22 , in the picking position of its additional knit thread  5 . The movement path of the second lifting needle  23  deviates from that of the first lifting needle  22 . The movement path of the lifting needle  23  is substantially a vertical up and down movement. It is carried out close to the weaving reed between the support ribbon warp threads  6  and the slantedly guided warp threads  6   a  for the woven strip  38 .  
         [0046]    [0046]FIG. 4 b  shows a further variant embodiment  100   b  of the needle ribbon weaving machine, again in a position analog to that of FIG. 4 with respect to the machine parts. This machine  100   b  is designed for manufacturing the zipper half  3   d  of FIG. 1 d.  The difference with respect to the weaving machine  100  resides in the use of the already aforementioned special warp threads  7  of which at least two are provided. The two warp threads  7  are guided oppositely during change of shed so that the two warp threads  7  are positioned alternatingly at the inner side of the lifting needle  22  for the lower warp threads  6   a  and at the outer side of the lifting needle  22  for the upper warp threads  6   a.  For the already aforementioned slanted movement path of the lifting needle  22  relative to the shed, the knit thread  4  is guided such that it penetrates above the warp threads  6   a  positioned in the lower shed but below the warp threads  6   a  positioned in the upper shed and at the same time penetrates between the two spread warp threads  7 . Accordingly, the knit thread  4  reaches the level of the hook needle  22  where the knit thread  4  is then crocheted with its loop heads. The hook needle  22 , as can be seen in FIG. 2, is supported and reciprocated by a carrier  29 . For the picking of the support ribbon weft in the form of the double loops  12  the weft picking needle  31  is provided. The knit thread  4 , in the form of double picks, is crossed with the warp threads  6   a  in the woven strip  38  below the closing member row  17  but also, as illustrated in FIG. 1 d,  with the special warp threads  7  at the upper side of the closing member row  17 .  
         [0047]    The FIGS. 5 a  to  6   b  show details of the device of FIGS. 2 through 4. On a weaving support  28  a cover  30  is arranged with spring action which serves for guiding the closing member row  17  illustrated in FIGS. 6 a  and  6   b.  The front part of this cover  20  serves as a stamping die  32 . As can be seen in FIG. 6 a  and  6   b,  the plastic monofilament thread  8  is guided into the space between the stamping die  32  and the rods  18   b  of the weaving reed  18 . Accordingly, the initially round cross-section of the monofilament thread  8  is flattened at the locations indicated by reference numeral  35  in FIGS. 6 a  and  6   b.  A spring  36 , illustrated in FIGS. 5 a  and  5   b,  acts on the cover  30  of the closing member guide.  
         [0048]    As is illustrated in FIG. 6 b,  the rods  18   b  have a certain spacing to the stamping die  32 . When winding the plastic monofilament thread  8  about the closing member guide pin  26 , the deformations  35  will be positioned at a right angle to the weaving plane. With these formations  35  the shaping of the locking member  8   c  can be affected favorably. The notch depth of the deformations  35  can be adjusted by an adjusting screw  32  illustrated in FIG. 6 b.  With these notches  35  the interlocking heads  8   d  for the closing members  8   c  to be formed thereof are produced when the plastic monofilament thread  8  is wound to a coil. The spacing between the individual notches  35  is selected according to the length of the closing member  8   c  to be formed. The rods  18   b  in the weaving reed  18  are spaced accordingly.  
         [0049]    While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.