Abstract:
A yarn tension control device of knitting machines is revealed. A plurality of yarn tension control devices is disposed on a knitting machine for control of warp yarns while weaving the warp yarns to produce fabrics. The warp yarns can be metal yarns. The metal yarns on a yarn disc are passed through a guide holder, bars for drop wires, and drop wires and then entered steel healds and reeds. Thus a constant yarn tension over the warp yarns is ensured by the yarn tension control devices during a weaving process of weft yarns. The tension of the metal yarns is the same with the tension of textile yarns. Thereby a stable yarn tension over the warp yarns gives uniform fabric appearance.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0001]    The present invention relates to a yarn tension control device, especially to a yarn tension control device used on a knitting machine for controlling tension of different warp yarns and providing a constant tension over the warp yarns on the knitting machine. Thus a stable yarn tension over the warp yarns gives uniform fabric appearance. 
       Description of Related Art 
       [0002]    Generally, yarns used on a warp beam of a knitting machine including rapier loom are textile yarns. After the textile yarns being passed through bars for drop wires, and drop wires and then entered steel healds and reeds, their tension is easily controlled within a certain range. During knitting of weft yarns, a constant tension over the warp yarns is required in the conventional textile technology. 
         [0003]    Refer to Fig. 1  and  FIG. 2 , a conventional rapier loom is revealed. Yarns on a warp beam  10  are textile yarns. After passed through a guide holder  91 , a back rest sensing roller  92 , bars for drop wires  93 , drop wires  94  and entered steel healds  95 , the tension of the yarns is easily controlled within a certain range. During weaving of weft yarns after passage of reeds  96 , a constant yarn tension over the warp yarns is ensured. After the weaving of the wefts on the warps, fabric formed by the textile yarns is drawn by a cloth roller  100 . In the conventional rapier loom, only common fabric can be drawn and produced because that a constant yarn tension over the yarns is required. 
         [0004]    Once metal yarns and textile yarns with different tensions are fed into the conventional knitting machine (including the rapier loom) and wound around the warp beam, warping is getting difficult. Besides increasing difficulty in warping, the different tensions of the metal yarns and the textile yarns from the yarn disc to the knitting machine for being woven lead to unstable yarn tension over the warp yarns. Thus the appearance of the fabric produced is uneven. 
         [0005]    Thus there is room for improvement and there is a need to provide a novel yarn tension control device that solves the problems mentioned above. 
       SUMMARY OF THE INVENTION 
       [0006]    Therefore it is a primary object of the present invention to provide a yarn tension control device that is applied to knitting machines for providing a constant yarn tension over different warp yarns on the knitting machine. Thus uniform fabric appearance is given by a stable yarn tension over the warp yarns during weaving. 
         [0007]    In order to achieve the above object, a yarn tension control device according to the present invention includes a main support, a yarn disc disposed on one side of the main support, a clamp support arranged at the other side of the main support, a rotary disc located in the clamp support, a rubber set disposed on the clamp support for control of rotational speed of the rotary disc, and a rotatable clamping roller connected to the main support. The knitting machine is arranged with a plurality of yarn tension control devices for control of metal yarns while weaving warp yarns to produce fabrics. The metal yarns on the yarn disc are passed through a guide holder, bars for drop wires, and drop wires and then entered steel healds and reeds. Thus a constant yarn tension over each warp yarn is ensured by the respective yarn tension control devices while knitting weft yarns. Therefore uniform fabric appearance is provided by a stable yarn tension over the warp yarns during the weaving process. 
         [0008]    An adjustment switch is arranged at the clamp support. The adjustment switch consists of a rod that is passed through an opening of the clamp support, a spring fit around the rod, and a knob fastened on a rear end of the rod for adjustment of an opening distance of the clamp support. 
         [0009]    The metal yarns or textile yarns are fixed on the yarn disc after warping so that the yarn tension control device is independent of the warp beam. The yarn tension control device is used to adjust and control a tension of the metal yarn or the textile yarn from the yarn disc. Thus a stable fabric take-off speed is reached according to the tension of the warp yarns on the warp beam, the running speed of the knitting machine and the fabric weft density so as to produce fabric with certain weft density. Therefore the appearance of the fabric produced is uniform. 
         [0010]    The yarn tension control device can be applied to knitting machines while producing special fabrics including conductive heating fabric, electromagnetic shielding fabric, radar absorbent fabric, etc. for control of tension of metal yarns or textile yarns in warp yarns therein. A plurality of yarn tension control devices is used while producing fabric. 
         [0011]    The yarns tension control device is used during weaving of fabric formed by textile yarns. A plurality of metal yarns is woven on edges of two sides of the fabric surface. The metal yarns can be conductive metal yarns or non-conductive metal yarns. 
         [0012]    The yarns tension control device is used during weaving of fabric formed by textile yarns. The fabric produced by textile yarns includes a plurality of textile yarns woven on edges of two sides of the fabric surface used as scrap yarns during knitting. 
         [0013]    The clamping roller is connected to one end of the connecting rod and a bearing is mounted in the clamping roller so as to make the clamping roller rotatable and able to press against the yarns on the yarn disc. The yarns can be metal yarns or textile yarns. 
         [0014]    In order to achieve the above object, a yarn tension control device according to the present invention includes a main support, a yarn disc and a rotary disc that are disposed on one side of the main support, a support fixing member arranged at one side of the rotary disc, an adjusting rod set moveable in the support fixing member, a belt mounted around the rotary disc for control of rotational speed of the rotary disc, and a rotatable a clamping roller connected to the main support. A plurality of yarn tension control devices is used for control of warp yarns respectively while weaving the warp yarns to produce fabrics. The warp yarns can be metal yarns. The metal yarns on the yarn disc are passed through a guide holder, bars for drop wires, and drop wires and then entered steel healds and reeds. Thus a constant yarn tension over the warp yarns is ensured by the yarn tension control devices during a weaving process of weft yarns. The tension of the metal yarns is the same with the tension of the textile yarns. Thereby a stable yarn tension over the warp yarns gives uniform fabric appearance. 
         [0015]    The adjusting rod set consists of an adjusting bolt and a locking nut. The adjusting bolt is passed through and moveable in a guide slot while the locking nut is fastened on the adjusting bolt and used for positioning the adjusting bolt in the guide slot. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein: 
           [0017]      FIG. 1  is a partial schematic drawing of a conventional rapier loom with a cloth roller; 
           [0018]      FIG. 2  is a partial schematic drawing of a conventional rapier loom with a warp beam; 
           [0019]      FIG. 3  is a schematic drawing showing embodiments of the present invention being disposed on a rapier loom with a warp beam according to the present invention; 
           [0020]      FIG. 4  is a schematic drawing showing embodiments of the present invention being disposed on a rapier loom with a cloth roller according to the present invention; 
           [0021]      FIG. 5  is a perspective view of a plurality of embodiments disposed on a frame of a knitting machine according to the present invention; 
           [0022]      FIG. 6  is a perspective view of an embodiment according to the present invention; 
           [0023]      FIG. 7  is a perspective view of an embodiment viewed from another angle according to the present invention; 
           [0024]      FIG. 8  is a front side view of an embodiment according to the present invention; 
           [0025]      FIG. 9  is a left side view of an embodiment according to the present invention; 
           [0026]      FIG. 10  is a right side view of an embodiment according to the present invention; 
           [0027]      FIG. 11  is a schematic drawing showing a side view of a rapier loom disposed with embodiments according to the present invention; 
           [0028]      FIG. 12  is a perspective view of another embodiment according to the present invention; 
           [0029]      FIG. 13  is a perspective view of another embodiment viewed from another angle according to the present invention; 
           [0030]      FIG. 14  is a perspective view of fabric produced by a knitting machine disposed with an embodiment according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0031]    In order to learn technical content, purposes and functions of the present invention, please refer to the following embodiments, related figures and reference numbers. 
         [0032]    Refer from  FIG. 1  to  FIG. 5 , a plurality of yarn tension control devices  2  according to the present invention is disposed over a knitting machine  1  while in use. 
         [0033]    The yarn tension control device  2  includes a main support  21  set over the knitting machine  1 . A main shaft  211  is passed through the main support  21  and is arranged with a yarn disc  22  and a rotary disc  25 . The yarn disc  22  is wound with yarns. A rotatable clamping roller  27  is disposed on the main support  21  and is used for pressing against the yarns of the yarn disc  22 . The yarn disc  22  and the rotary  25  are rotated at the same speed along with the yarns being drawn by an external force. A friction damper B is set on one side of the rotary disc  25  correspondingly and is used to control and adjust rotational speed of the rotary disc  25 . 
         [0034]    While in use, the friction damper B in the yarn tension control device  2  can adjust and control the rotational speed of the rotary disc by frictional resistance, tightness of the belt or arrangement of the electric brake system. 
         [0035]    Refer to  FIG. 5 ,  FIG. 6 ,  FIG. 7  and  FIG. 8 , a yarn tension control device  2  according to the present invention is composed of a main support  21 , a yarn disc  22 , a clamp support  23 , a rotary disc  25 , a rubber set  26  and a rotatable clamping roller  27 . 
         [0036]    The main support  21  is a base installed over the knitting machine  1 . A main shaft  211  and a connecting rod  212  are passed through and arranged at the main support  21  while a fixing base  213  is disposed on one end of the main shaft  211 . 
         [0037]    The yarn disc  22  is fit on the fixing base  213  and is wound with yarns (including metal yarns  4  or textile yarns  5 ). The yarns are used for warp knitting. 
         [0038]    The clamp support  23  is disposed on one end of the connecting rod  212  and an adjustment switch  24  is arranged at a rear end of an opening of the clamp support  23 . 
         [0039]    The rotary disc  25  is connected to the other end of the main shaft  211  and located in the opening of the clamp support  23 . 
         [0040]    The rubber set  26  is fixed in the opening of the clamp support  23  and located on the left side and the right side of the rotary disc  25 . 
         [0041]    The rotatable clamping roller  27  is arranged at the other end of the connecting rod  212  and is used for pressing against the yarn around the yarn disc  22 . 
         [0042]    Refer to  FIG. 3 ,  FIG. 4  and  FIG. 5 , a plurality of yarn tension control devices  2  is installed on a frame  11  of the knitting machine  1  (the conventional rapier loom shown in  FIG. 3  and  FIG. 4 ) while in use. The yarn  22  of the yarn disc  22  includes metal yarns  4  or textile yarns  5 . After being passed through a guide holder  6 , bars for drop wires  93  and drop wires  94 , the metal yarns  4  are entered steel healds  95 . At the same time, general textile yarns  5  on a warp beam  10  are also passed through a guide bar  91 , a back rest sensing roller  92 , the bars for drop wires  93 , the drop wires  94  and entered the steel healds  95 . Then the metal yarns  4  and textile yarns  5  are passed through different reeds  96  respectively. After being weaved with weft yarns  7 , blended fabric A formed by the metal yarns  4  and the textile yarns  5  is obtained. 
         [0043]    Refer from  FIG. 6  to  FIG. 11 , a bearing  3  is mounted in the main support  21  of the yarn tension control device  2 . After the main shaft  211  being passed through the bearing  3 , one end of the main shaft  211  is set with the fixing base  213  and the yarn disc  22  while the other end of the main shaft  211  is arranged with the rotary disc  25  so as to form a linked rotating mechanism. Then the clamping roller  27  is connected to one end of the connecting rod  212  and another bearing  3  is mounted in the clamping roller  27  so as to form the rotatable clamping roller  27  that is pressed against the yarns on the yarn disc  22  (including the metal yarns  4  and the textile yarns  5 ). 
         [0044]    The other end of the connecting rod  212  on the main support  21  is set with the clamp support  23 . The clamp support  23  is a C-shaped piece with an opening while the rotary disc  25  is located in the opening of the clamp support  23  and the rubber set  26  corresponding to the rotary disc  25  is disposed on the clamp support  23 . The rubber set  26  is fixed in the opening of the clamp support  23  and located on the left side and the right side of the rotary disc  25 . Then a rear end of an opening of the clamp support  23  is arranged with the adjustment switch  24 . As shown in  FIG. 8 , the adjustment switch  24  consists of a rod  241 , a spring  242  and a knob  243 . The rod  241  is passed through the opening of the clamp support  23  and the spring  242  is set around the rod  241  while the knob  243  is fastened on a rear end of the rod  241  for adjustment of friction of the rubber set  26  with respect to the rotary disc  25 . The rotational speed of the rotary disc  25  is affected by the rubber set  26 . Thus the magnitude of the speed and the tension of the metal yarns  4  or the textile yarns  5  being drawn into the knitting machine  1  can be controlled. 
         [0045]    The rubber set  26  has a two-piece structure. The tension of the yarns on the yarn disc  22  is increased when the knob  243  is turned for adjustment of the tension of the spring  242  and the two-piece rubber set  26  clips the rotary disc  25  more tightly. On the other hand, the tension of the yarns is reduced while the rotary disc  25  is clamped less tightly. Thus users can turn the knob  243  for adjustment of the yarn tension according to their requirements on production. 
         [0046]    Moreover, besides the tightness of the rubber set  26 , the rotational speed of the rotary disc  25  can also be affected by other factors. Refer to  FIG. 12  and  FIG. 13 , another embodiment of the present invention is revealed. In this embodiment, a yarn tension control device  2  includes a main support  21 , a yarn disc  22 , a rotary disc  25 , a rubber set and a clamping roller  27 . 
         [0047]    The main support  21  is a base installed over the knitting machine  1  and a main shaft  211  is passed therethrough. 
         [0048]    The yarn disc  22  is fit on the main shaft  211  and is wound with yarns. 
         [0049]    The rotary disc  25  is arranged at the main shaft  211 , and located on one side of the yarn disc  22 . A guide groove  251  is disposed around the circumference of the rotary disc  25 . 
         [0050]    The rubber set is located on one side of the rotary disc  25  and having a support fixing member  28  and a belt  29 . The support fixing member  28  including a guide slot  281  is set on one end of the main support  21  while an adjusting rod set  30  is passed through the guide slot  281  and is moveable in the guide slot  281 . The belt  29  is mounted in the guide groove  251  and wound around the rotary disc  25 . One end of the belt  29  is a fixed end  290  while the other end thereof is disposed with a hook spring  291  being hooked to the adjusting rod set  30 . The friction of the belt  29  in relation to the rotary disc  25  can be adjusted by displacement of the adjusting rod set  30 . 
         [0051]    The clamping roller  27  is rotatable and is arranged at the main support  21  for pressing against yarns around the yarn disc  22 . 
         [0052]    Refer to  FIG. 12  and  FIG. 13 , this embodiment is disposed on a knitting machine in a similar way as the embodiment mentioned above. The difference between this embodiment and the above one is in that friction damping is from the belt in this embodiment. In both embodiments, the main support  21  is arranged with a bearing  3  therein. The main shaft  211  is disposed with the yarn disc  22  and the rotary disc  25  respectively after being passed through the main support  21  to form a linked rotating mechanism. Then another bearing  3  is mounted in the clamping roller  27  so that the clamping roller  27  is rotatable and able to press against the yarns on the yarn disc  22 . The yarns can be metal yarns  4  or textile yarns  5 . 
         [0053]    Next the support fixing member  28  of the rubber set is fastened and fixed on the main support  21 . The adjusting rod set  30  is passed through the guide slot  281  of the support fixing member  28 . The adjusting rod set  30  consists of an adjusting bolt  301  and a locking nut  302 . The position of the adjusting bolt  301  in the guide slot  281  is fixed by the locking nut  302  after being inserted through the guide slot  281  and being adjusted properly. One end of the belt  29  is a fixed end  290  that is fixed on the main support  21  or is positioned at a rod which the clamping roller  27  is disposed on. Later the belt  29  is mounted in the guide groove  251  and wound around the rotary disc  25 . As to the hook spring  291  on the other end of the belt  29 , it is hooked onto the adjusting rod set  30 . Thus friction damping that works on the rotary disc  25  is generated by the belt  29 . 
         [0054]    The further the adjusting bolt  301  is away from a fixed end on top of the guide slot  281 , the tighter and closer the belt  29  is clamped while the adjusting bolt  301  being adjusted and moved in the guide slot  281 . That means the larger the yarn tension of the yarns on the yarn disc  22 . On the other hand, the looser the belt  29 , the smaller the yarn tension is. Users can adjust the adjusting rod set  30  according to their own requirements on production. 
         [0055]    Refer to  FIG. 14 , the present yarn tension control device is suitable to be applied to fabric A made from the textile yarns  5 . The fabric edge on each of two sides of the fabric A is woven with a plurality of the metal yarns  4  that are metal yarns or non-conductive metal yarns. The fabric A produced can be conductive heating fabric, electromagnetic shielding fabric or radar absorbent fabric. 
         [0056]    The present yarn tension control device  2  can also be used to weave the textile yarns  5  for control of tension of the textile yarns  5  being drawn. During knitting, a plurality of textile yarns  5  is weaved on edges of two sides of the fabric surface and used as scrap yarns. The textile yarns  5  can be pure yarns or blended yarns. 
         [0057]    Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, and representative devices shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalent.