Abstract:
Disclosed is an apparatus for whipping a button sewing thread, capable of ensuring the operational convenience, reliability and durability by simplifying main elements of the apparatus. The apparatus includes a body including a holder for holding a sewed button; a tension control unit provided with a plurality of tensioners and a thread hook on a passage of the thread; a thread guide unit adjacent to the tension control unit to guide the thread toward the holder; a winding unit including a rotational arm for winding the thread around a sliding support linearly moving toward the holder; and a knotting unit including a separating arm linearly moving toward the holder in order to form a thread knot.

Description:
BACKGROUND 
     The present invention relates to an apparatus for whipping a button sewing thread, and more particularly, to an apparatus for whipping a button sewing thread, capable of ensuring the operational convenience, reliability and durability by simplifying main elements of the apparatus. 
     In cases of typical clothes, buttons are sewed onto the clothes with a sewing thread (called a “root”) to be spaced apart from each other by a predetermined distance so that the buttons easily enter buttonholes of the cloths. To improve the support strength of such a root, a plurality of knots is formed around peripheries of the buttons by using another sewing thread. Similarly to other industrial fields, various automatic machines have been developed in the field of a button sewing machine in order to improve productivity by saving labor force required for whipping a button sewing thread. The related arts have been disclosed in Korean Utility Model Registration No. 20-0322717 and Korean Patent No. 10-0532713. 
     According to the former related art, a plurality of guide bars for guiding a hemming thread in zigzag are provided and are instantly moved up in the late period of a hemming process to prevent the hemming thread from being released. When an air pressure for driving a latch piece of a button latch part is removed, the operation of the hemming device is automatically stopped to prevent the hamming thread from being tangled around the latch piece or the button base. Thus, it is expected to improve the efficiency of works related to the process of hemming the button base. 
     However, according to the above related art, the guide bars for guiding a hemming thread in zigzag may serve as main elements, so the knots are unstable and weak when the knots are formed at a high-speed operation, so that there may be a limitation in maintaining the stable hemming state. 
     According to the later related art, there is provided an apparatus for wrapping and knotting a thread to the side of a sewing button of a cloth. The apparatus includes a base, a button holder mounted on the base for supporting the button on the base, a knot guider for hooking the thread to the side surface of the button supported by the button holder to form a knot, a slider movable forward and rearward on the base, and a winding member having a winding arm for winding the thread around the side surface of the button. Thus, the thread may form a strong knot at the side surface of the sewing thread of the button so that the thread is not untied. 
     However, since the mechanical configuration of the knot guider for reciprocating and retracting motions to form a knot is complex, a malfunction may be caused due to abrasion and it is difficult to manage and maintain the knot guider, so that the durability may be deteriorated. In addition, when the thread is cut, the passage formed by the first and second tube members communicating with each other is complex so that it is inconvenient to resupply the thread. 
     SUMMARY 
     Accordingly, it is an object of the present invention to provide an apparatus for whipping a button sewing thread, capable of ensuring the operational convenience, convenient maintenance, reliability and durability by simplifying main elements of the apparatus. 
     According to the present invention, there is provided an apparatus for whipping a button sewing thread with a thread. The apparatus includes a body including a holder for holding a sewed button; a tension control unit provided with a plurality of tensioners and a thread hook on a passage of the thread; a thread guide unit adjacent to the tension control unit to guide the thread toward the holder; a winding unit including a rotational arm for winding the thread around a sliding support linearly moving toward the holder; and a knotting unit including a separating arm linearly moving toward the holder in order to form a thread knot. 
     According to the present invention, the thread hook of the tension control unit has a hole adjacent to a downstream tensioner, and performs a thread hooking operation in cooperation with an air cylinder. 
     According to the present invention, the thread guide unit is formed with a through hole extending to an end of the rotational arm and includes an air nozzle at an upstream end of the through hole to convey the thread. 
     According to the present invention, the sliding support of the winding unit includes a spline shaft and is installed to a motor support such that the sliding support is linearly movable through the spline shaft, and the rotational arm receives a torque through a driving motor and the motor support. 
     According to the present invention, the knotting unit includes an air cylinder for moving the separating arm back and forth and a convey motor for moving the rotational arm back and forth. 
     As described above, according to the present invention, the main elements of the apparatus and the transferring passage of the thread can be simplified so that the operational convenience and the maintenance can be improved. In addition, the reliability in the operation of wrapping the button sewing thread and durability can be achieved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plane view showing an entire apparatus according to an embodiment of the present invention; 
         FIG. 2  is a view illustrating a winding operation of an apparatus according to an embodiment of the present invention; 
         FIG. 3  is an enlarged view showing main elements for a knot operation of an apparatus according to an embodiment of the present invention; and 
         FIGS. 4 and 5  are views illustrating a winding operation of an apparatus according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, the embodiments of the present invention will be described with reference to the accompanying drawings. 
     As shown in  FIGS. 1 and 2 , the present invention provides an apparatus for whipping a sewing thread of a button B with a thread. The button B is provided to the apparatus according to the present invention in the state the button B is sewed to clothes. In this case, the thread used to couple the button B to the clothes is called a sewing thread (is called a root). Another thread T is provided to another apparatus according to the present invention to surround the sewing thread between the conventional clothes and the button B so that the sewing thread is reinforced. 
     As shown in  FIGS. 1 and 2 , a body  10  according to the present invention has a holder  12  to which the sewed button B is held. The holder  12 , which is a member having a circular shape and a substantially curved surface, is fixed to the top surface of the body  10 . The curved surface of the holder  12  is provided to allow the button B attached to the clothes to be placed thereon so that the position of the button is fixed to expose a sewing line. Referring to  FIG. 1 , a lower direction, in which the holder  12  of the body  10  is placed, is referred to as a front direction or surface, and an upper direction is referred to as a rear direction or surface. 
     In this case, the holder  12  of the body  10  includes a straight groove  14 , a V-shaped groove  15 , and a concave groove  16 . The straight groove  14  is formed by incising the holder  12  in the longitudinal direction such that the sewing thread of the button B is held while passing through the straight groove  14 . The V-shaped groove  15  is incised toward an upper side of the straight groove  14  such that the separating arm  51  described later is rested therein. The concave groove  16  is formed on a rear surface of the holder  12  in an arc shape to knot the thread T in a figure “8” shape. 
     A tension control unit  20  according to the present invention includes tensioners  21 ,  22  and  23  and a thread hook  25  on a passage of the thread T. The thread T is provided to the holder  12  from a rear side end through a tensioner  21  positioned upstream, a middle tensioner  22  and a tensioner  23  positioned downstream. A thread hook  25  is disposed between the tensioners  21  to  23  to maintain the tension necessary when the thread T is wound and knotted. 
     The thread hook  25  of the tension control unit  20  has a hole  26  formed adjacent to the tensioner  23  positioned downstream and the tension control unit  20  performs the thread hooking operation in cooperation with an air cylinder  24 . The thread hook  25  provides a tension to the thread T which passes intermittently through the hole  26  in an up-and-down motion to help the thread T to be wound and knotted. When the hole  26  is adjacent to the tensioner  23  positioned downstream), the relaxation of the thread T is reduced so that there are advantages of always providing a suitable tension. A hinge is installed at an opposite side to the hole  26  of the thread hook  25  such that the intermittent movement of the hinge toward the air cylinder  24  in an up-and-down motion is induced. Thus, the configuration for the operation of the thread hook  25  is simple and it is easy to adjust the tension through the air pressure control. 
     Further, according to the present invention, a thread guide unit  30  is installed adjacent to the tension control unit  20  to guide the movement of the thread T toward the holder  12 . The thread guide unit  30  allows the thread T passing through the thread hook  25  and the tensioner  23  of the tension control unit  20  to move smoothly through a rotational arm  41  described below and to be installed quickly and conveniently at a first work stage and during working. The detailed configuration of the thread guide unit  30  will be described below. 
     According to the present invention, the winding unit  40  includes the rotational arm  41  for allowing the thread T to be wound around a sliding support  44  linearly moving in the direction of the holder  12 . The winding unit  40  performs the function of winding the thread T along a periphery of a sewing line of the button B by using the holder  12  and the rotational arm  41 . The separating arm  51  has a shape of a bending tube and is eccentrically fixed onto the sliding support  44 . The sliding support  44  is installed on the upper surface of the body  10  such that the sliding support  44  may linearly move back and forth with respect to the holder  12 . 
     The sliding support  44  is installed to a motor support  42  such that the sliding support  44  can linearly move through the spline shaft  43  interposed between the sliding support  44  and the motor support  42 . The rotational arm  41  receives a torque through a driving motor  46  and the motor support  42 . The torque of the driving motor  46  is transferred to the spline shaft  43  through the motor support  42 . The motor support  42  includes a gear and a timing belt and is fixed to the body  10  while being received in a housing. The sliding support  44  is connected to the spline shaft  43  in a rear direction and is provided with the rotational arm  41  in a front direction. Thus, when the thread T is wound and knotted, the torque of the driving motor  46  may be continuously provided to the rotational arm  41  while the sliding support  44  is linearly moving. 
     In addition, according to the present invention, a knotting unit  50  linearly moves toward the holder  12  and includes the separating arm  51  for forming a knot of the thread T. The knotting unit  50  knots the thread T which is wound around the periphery of the button B by using the holder  12  and the separating arm  51 . A guide rail is provided to an upper end of the motor support  42  such that the separating arm  51  is coupled to the guide rail to be movable in a linear motion. 
     The knotting unit  50  includes an air cylinder  54  for allowing the separating arm  51  to move back and forth and a convey motor  56  for allowing the rotational arm  41  to move back and forth. The air cylinder  54  is fixed to the upper end of the motor support  42  such that the air cylinder  54  is connected to the guide rail. As shown in  FIGS. 2 and 4 , an end of the separating arm  51  approaches to or is spaced apart from the holder  12  as the air cylinder  54  is operated. The convey motor  56  is mounted on a lower surface of the body  10  and is connected to the sliding support  44  by interposing a gear between them. Although the sliding support  44  linearly moves forward and rearward as the convey motor  56  is operated, as described above, since the spline shaft  43  is interposed, the torque can be continuously transferred from the driving motor  46  to the rotational arm  41 . 
     Referring to  FIG. 3 , the separating arm  51  includes two members, each of which is bent in a reverse-L shape and is placed to be closest to the V shaped groove  15  of the holder  12 . The separating arm  51  is provided at an end thereof with a latch piece  53 , such that the thread T wound around the concave groove  16  of the holder  12  is exactly separated from the holder  12 . The latch piece  53  is formed by bending the lower end of the bending member, which is bent in the reverse-L shape, in the rearward direction. 
     The thread guide unit  30  has a through-hole extending to the end of the rotational arm  41  and includes an air nozzle  35  for transferring the thread T from an upstream end of the through-hole. After the thread T has passed through the thread hook  25  and the tensioner  23 , the thread T passes through the upstream through-hole  31  and the downstream through-hole  32  and then is supplied to the holder  12 . The upper side through-hole  31  includes a hollow formed in the spline shaft  43  and the lower side through-hole  32  includes a hollow formed in the rotational arm  41 . Since the through-holes  31  and  32  are integrally formed and the air nozzle  35  is provided at the end of the through-hole  31 , the thread T can be quickly and conveniently introduced in the early stage of operation or during the operation. 
     The operations of the apparatus according to the present invention may be widely divided into the winding operation of  FIG. 2  and the knotting operation of  FIGS. 4 and 5 . 
     In  FIG. 2 , when a switch (not shown) is pressed in a state that the cloth makes contact with the holder  12  to expose the button B, the driving motor  46  and the convey motor  56  are operated to rotate and linearly move the rotational arm  41  so that the thread T is wound along the sewing line. The number of winding the thread T is preset in a controller (not shown). 
     In  FIG. 4 , when the thread T has been wound at the preset number, the sliding support  44  move forward so that the end of the rotational arm  41  arrives at the concave groove  16  of the holder  12 . Thus, the rotational arm  41  winds the thread T around the concave groove  16 . Then, as shown in  FIG. 5 , the air cylinder  54  is operated to retract the separating arm  51 , so that the thread T of the concave groove  16  is separated, and at the same time, entangled with the thread T of the rotational arm  41 , thereby forming the knot. The scheme of forming a knot having a figure “8” shape is generally known in the art. 
     In addition, the sequential operations of  FIGS. 2, 4 and 5  may be repeated at the number of times preset in the controller. 
     Although an exemplary embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.