Patent Publication Number: US-10758019-B2

Title: Flap fixing buckle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority from Korean Patent Application No. 10-2017-0040696, filed on Mar. 30, 2017, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a flap fixing buckle, and more particularly, to a flap fixing buckle capable of allowing a flap for covering an opening of a bag, a backpack, or a knapsack to be conveniently fixed, and capable of providing an aesthetic external appearance that is simply organized. 
     BACKGROUND 
     In general, various types of bags or cases such as bags, knapsacks, backpacks, handbags, mobile phone cases, and jotter cases (hereinafter, referred to as a ‘bag’) are each provided with an accommodation space therein, an opening which communicates with the outside, and a means for opening and closing the opening. 
     Among others, a bag, which is provided with a flap for covering an opening, is also widely used. A fastening means is installed at a free end of the flap so as to be attached to or detached from a bag body, such that the opening of the bag is closed or opened by fixing or separating the flap. 
     Patent Documents 1 and 2 disclose that magnets are provided on corresponding surfaces of the free end of the flap and the bag body so that the flap is attached to the bag body by coupling the magnets. The configuration in which the flap and the bag body are attached to each other by means of the magnets as described above is applied to and used for various accommodating structures such as jotter cases or mobile phone cases as well as the bag. 
     While a small-sized bag such as a handbag or a mobile phone case has a fixed size, a larger bag such as a backpack or a knapsack requires a long fixing means to correspond to the amount of items accommodated therein. To this end, a strap is provided on the flap, a magnet is provided on the strap, and a buckle of which the position is adjustable is provided on the strap so that a length of the strap may be adjusted. 
       FIG. 1  illustrates an example of a bag provided with a flap in the related art. As illustrated in  FIG. 1 , a flap F for opening and closing an opening of a bag B is openably and closably provided on an upper end portion of the bag B, and straps S 1  are provided on the flap F and extend to the outside from the flap F. Buckles  1  are provided at free ends of the straps S 1  so as to be fixed to or separated from a bag body B. 
     There is applied a fastening structure in which multiple holes are formed in the strap S 1  so that the strap S 1  is coupled to the buckle  1  having a hook and a position is adjusted as the hook is coupled to or decoupled from the hole, and as a result, a range to be covered by the flap F may be adjusted, and a magnet is attached to the buckle so that the buckle may be conveniently fastened and separated. 
     The combination of the strap and the buckle having the hook provides a decorative effect by itself and is substantially intended to provide a convenient manipulation by means of attachment and detachment of the magnet. 
       FIG. 2  is a photograph specifically illustrating an example of a bag in the related art in which a strap of a flap is fastened by a magnet, and  FIG. 3  is a partial side view illustrating a state in which the strap and a buckle illustrated in the  FIG. 2  are coupled to a bag body. As illustrated in  FIGS. 2 and 3 , a first magnet  11  is embedded in the bag body B, and a buckle  1  of which the position is adjustable is provided on the strap S extending from the flap F. 
     An auxiliary strap S- 1  is connected to the buckle  1 , and a second magnet  21  is provided at an end portion of the auxiliary strap S- 1  so that the second magnet  21  is attached to or detached from the first magnet  11  provided on the bag body B. 
     Any one of the first magnet  11  and the second magnet  21  may be made of metal. 
     The flap fastening structure of the bag in the related art has the following problems. 
     1. The dual structure includes the strap S which is fastened to the buckle  1 , and the auxiliary strap S- 1  which is connected to the buckle  1  and attached to or detached from the bag body B, and as a result, the dual structure is very complicated, such that there occurs a defect in an external appearance of the bag. 
     2. The protruding complicated straps and the protruding buckle easily collide with outside objects, and as a result, there is a problem in that the straps and the buckle are easily separated. 
     3. Because of a number of subsidiary elements, there is a problem in that costs are increased, it is difficult to manufacture the product, and a process is complicated. 
     4. It is necessary to necessarily separate the auxiliary strap positioned below the strap in order to disassemble the flap. That is, it is necessary to perform an inconvenient operation of lifting up the strap S and holding the magnet of the auxiliary strap S- 1  to separate the magnet. 
     5. Because the attached magnet is exposed, there is concern that the magnet is likely to be damaged due to external impact. 
     6. There is a problem in that it is difficult to adjust the strap in accordance with a volume of the bag, and the attached magnet is easily separated and lost as the bag is used. 
     Therefore, to solve the aforementioned problems, there is a need for a flap fixing buckle capable of providing an organized external appearance and capable of being more conveniently used. 
     DOCUMENTS OF RELATED ART 
     Patent Documents 
     
         
         1. Korean Utility Model Application Laid-Open No. 2001-0000532 (Jan. 5, 2001) 
         2. Korean Utility Model Registration No. 20-0216902 (Jan. 4, 2001) 
       
    
     SUMMARY 
     The present disclosure has been made in an effort to provide a flap fixing buckle which has a non-complicated external appearance and may be conveniently used. 
     The present disclosure has also been made in an effort to provide a flap fixing buckle which may maintain stable engagement of the buckle regardless of external contact and may prevent the magnet from being damaged by external impact. 
     The present disclosure has also been made in an effort to provide a flap fixing buckle capable of providing a simple structure that allow the buckle to be easily manufactured and reduces costs. 
     An exemplary embodiment of the present disclosure provides a flap fixing buckle including: a plug member having a cross bar that transverses an intermediate portion of a loop-shaped frame, in which a coupling protruding portion in which a first magnet is embedded protrudes from the cross bar; and a socket member having a coupling groove into which the coupling protruding portion is inserted and which is formed in an upper surface of the socket member, in which a second magnet is embedded inside the coupling groove. 
     Another exemplary embodiment of the present disclosure provides a flap fixing buckle including: catching grooves may be formed in lateral surfaces of the coupling protruding portion, protruding portions may protrude from a circumferential edge portion of the coupling groove so as to face one another, and catching protrusions may be formed on lateral surfaces of the protruding portions which face one another, such that the catching protrusions are coupled to the catching grooves when the coupling protruding portion is inserted into the coupling groove. 
     Another exemplary embodiment of the present disclosure provides a flap fixing buckle including: a plug member having a cross bar that transverses an intermediate portion of a loop-shaped frame, in which a coupling protruding portion in which a first magnet is embedded protrudes from the cross bar; and a socket member having multiple guide protruding portions that protrude from an upper surface of the socket member such that a coupling groove into which the coupling protruding portion is inserted is formed between the guide protruding portions, in which a second magnet is embedded inside the coupling groove. 
     Four guide protruding portions may be formed to face one another so that a “+” shaped groove is formed between the guide protruding portions. 
     Further, catching protrusions may be formed inside the guide protruding portions, and catching grooves, which are coupled to the catching protrusions, may be formed in lateral surfaces of the coupling protruding portion. 
     A strap, which is installed on a flap of a bag and has holes formed at predetermined intervals, may be inserted into the frame, and a hook may be rotatably coupled to an intermediate portion of the cross bar and inserted into the hole of the strap, such that the strap and the plug member are coupled to each other, and the socket member may be attached and installed at one end of a bag body in a state in which the socket member is embedded so that the coupling groove is exposed to the outside, such that the plug member and the socket member are attached by magnetic force. 
     The frame may be formed such that lower ends of the intermediate portion, which face each other, protrude and extend downward, and the cross bar may be formed on the protruding portions. 
     The socket member may be attached and installed at one end of a bag body in a state in which the socket member is embedded so that the coupling groove is exposed to the outside. 
     The socket member is coupled at one end of the bag body by sewing or adhesion. 
     A circumferential edge portion of the socket member may further extend outward to form a wing portion, such that the socket member is easily attached to the bag body. 
     A hook groove may be formed in the intermediate portion of the coupling groove so as to intersect the intermediate portion of the coupling groove, such that the hook is accommodated in the hook groove when the coupling protruding portion is coupled. 
     Still another exemplary embodiment of the present disclosure provides A flap fixing buckle including: a bag body; a flap which is configured to open and close an opening of the bag body and has a strap installed at a tip portion thereof; a plug member having a cross bar that transverses an intermediate portion of a loop-shaped frame, in which the strap is inserted into the plug member so as to be fixed by a hook or separated, and a coupling protruding portion in which a first magnet is embedded protrudes from the cross bar; and a socket member having a coupling groove into which the coupling protruding portion is inserted and which is formed in an upper surface of the socket member, in which a second magnet is embedded inside the coupling groove, and a wing portion extends at the periphery of the upper surface of the socket member, such that the wing portion is fixedly attached to one end of the bag body. 
     According to the flap fixing buckle according to the present disclosure, there is provided the simplified structure that includes the plug member which has the cross bar on which the coupling protruding portions are formed, and the socket member which is fixedly embedded in the bag body and has the coupling groove into which the coupling protruding portions are coupled. Therefore, it is possible to form an aesthetic external appearance that is not complicated, and to provide convenience by allowing the flap fixing buckle to be attached or detached by a simple operation. 
     According to the flap fixing buckle according to the present disclosure, the magnet is safely embedded without being exposed to the outside, thereby providing stability since the magnet is not easily separated or damaged due to external contact or impact. 
     According to the flap fixing buckle according to the present disclosure, costs may be reduced and effective productivity may be provided because of the simple configuration. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view of an exemplary embodiment of a general bag having a flap and straps. 
         FIG. 2  is a partial photograph illustrating an example of the straps provided on the flap of the bag in the related art. 
         FIG. 3  is a partial side view illustrating a state in which the strap illustrated in  FIG. 2  is installed. 
         FIG. 4  is a perspective view illustrating a state in which a plug member and a socket member of a buckle according to the present disclosure correspond to each other. 
         FIG. 5  is an exploded bottom perspective view of the buckle according to the present disclosure. 
         FIG. 6  is a bottom perspective view of the plug member according to the present disclosure. 
         FIG. 7  is a view illustrating a coupled state in a cross section taken along line A-A in  FIG. 4 . 
         FIG. 8  is a view illustrating a state in which the buckle according to the present disclosure is installed. 
         FIG. 9  is a perspective view illustrating a state in which a plug member and a socket member of another type of buckle according to the present disclosure correspond to each other. 
         FIG. 10  is an exploded bottom perspective view of  FIG. 9 . 
         FIG. 11  is a bottom perspective view of the plug member illustrated in  FIG. 9 . 
         FIG. 12  is an exploded perspective view illustrating still another type of buckle according to the present disclosure. 
         FIG. 13  is a perspective view illustrating a coupled state of  FIG. 12 . 
         FIG. 14  is a perspective view of a buckle according to a second exemplary embodiment of the present disclosure. 
         FIG. 15  is a bottom perspective view of a socket member according to the second exemplary embodiment. 
         FIG. 16  is a lateral view illustrating a coupled state according to the second exemplary embodiment. 
         FIG. 17  is a view illustrating a state in which the buckle according to the second exemplary embodiment is installed and used. 
         FIG. 18  is an exploded perspective view illustrating another type of the second exemplary embodiment. 
         FIG. 19  is a perspective view illustrating a coupled state of  FIG. 18 . 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawing, which forms a part hereof. The illustrative embodiments described in the detailed description, drawing, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. 
     Hereinafter, specific contents of the present disclosure will be described in detail with reference to the accompanying drawings. Here, thicknesses of lines illustrated in the drawings, sizes of constituent elements, or the like may be exaggerated for clarity and convenience of description. 
     The terms used in the following description are defined considering the functions in the present disclosure and may vary depending on the intention or usual practice of a user or an operator. Therefore, the definition of the terms should be made based on the entire contents of the present specification. 
       FIGS. 4 to 8  illustrate a first exemplary embodiment of the present disclosure. 
       FIG. 4  is a perspective view illustrating a state in which a plug member and a socket member of a buckle according to the present disclosure correspond to each other,  FIG. 5  is an exploded bottom perspective view of the buckle according to the present disclosure,  FIG. 6  is a bottom perspective view of the plug member according to the present disclosure, and  FIG. 7  is a view illustrating a coupled state in a cross section taken along line A-A in  FIG. 4 . As illustrated in  FIGS. 4 to 7 , a buckle  100  according to the present disclosure basically and broadly includes a plug member  110  and a socket member  120 . 
     The plug member  110  includes a frame  111  which has a loop shape, a cross bar  112  which traverses a lower intermediate side of the frame  111 , and a hook  113  which is coupled to an intermediate portion of the cross bar  112 . 
     The frame  111  is illustrated in the drawings as having a quadrangular loop shape, but the shape of the frame  111  is just optional. 
     A strap is interposed between the frame  111  and the cross bar  112 . As illustrated in  FIG. 8 , a strap S 1  enters the frame  111  from a lower side of the frame  111 , travels over an upper side of the cross bar  112 , and exits the frame  111  from an opposite lower side of the frame. Central portions of lateral portions of the frame  111  extend downward and the cross bar  112  is formed at lower ends of the central portions so that the strap may be smoothly interposed, and as a result, the cross bar  112  is positioned to further protrude downward in comparison with a circumferential edge portion of the frame  111 . 
     Coupling protruding portions  115  are formed at both sides of the cross bar  112 . The coupling protruding portion  115  may have a quadrangular cross section, and a first magnet  116  is embedded in a lower surface of the coupling protruding portion  115 . 
     A recessed portion is formed in the intermediate portion of the cross bar  112  as the coupling protruding portions  115  are formed at both sides, and the hook  113  is installed in the recessed portion. 
     The hook  113  is fitted to be wound around the cross bar  112  so that the hook  113  is rotated about the cross bar  112 . A tip portion of the hook  113  is elongated and inserted into a hole  130  formed in the strap S 1 , such that the hook  113  is fastened to the strap S 1 . 
     A catching projection  114  is formed at an intermediate portion of the hook  113 . When the hook  113  is inserted into the hole  130  of the strap S 1 , the catching projection  114  prevents the tip portion of the hook  113  from excessively protruding while penetrating the strap S 1 . 
     The socket member  120  is formed in a thin plate shape, and a coupling groove  121  into which the coupling protruding portions  115  are inserted is formed in an upper surface of the socket member  120 . A second magnet  123  is embedded in a bottom surface of the coupling groove  121 . 
     As illustrated in  FIG. 7 , the plug member  110  and the socket member  120  remain coupled by magnetic force as the coupling protruding portions  115  of the plug member  110  are inserted into the coupling groove  121  of the socket member  120 . 
     The socket member  120  is embedded at one end of a bag body B 1 . To this end, a circumferential edge portion of the upper surface of the socket member  120  extends outward such that a wing portion  122  may be formed. The wing portion  122  is attached to an outer sheath that defines the bag body B 1 . 
     As illustrated in  FIG. 8 , the wing portion  122  of the socket member  120  is coupled, by sewing, to the outer sheath of the bag body B 1  in a state in which the coupling groove  121  is exposed. Alternatively, the wing portion  122  may be fixedly attached by a bonding agent. Reference numeral ‘140’ indicates a sewed line. 
     A hook groove  124 , which extends toward both sides, is formed in an intermediate portion of the coupling groove  121 , thereby ensuring a space which may accommodate the hook  113  that protrudes laterally when the coupling protruding portions  115  are inserted. 
     The movements of the coupling protruding portions  115  are prevented as the hook  113 , which further protrudes laterally than the coupling protruding portions  115 , is coupled to the hook groove  124  when the coupling protruding portions  115  and the hook  113  are coupled, such that a larger contact area is ensured, thereby maintaining a more stably coupled state. 
     That is, when an unintentional action, such as external contact, of separating the buckle occurs, a simple coupled state of the coupling groove  121  and a coupled state of the hook groove  124 , which intersects the coupling groove  121 , complexly act, thereby preventing abnormal withdrawal of the plug member  110 . 
     In the present disclosure configured as described above, the socket member  120  is embedded at one end of the bag body B 1 , the strap S 1  connected to the flap F 1  is inserted into the frame  111  of the plug member  110 , and the hook  113  is inserted into and connected to the hole  130 . 
     The multiple holes  130  are formed at predetermined intervals in the strap S 1 , and as a result, it is possible to adjust a position of the plug member  110  by changing, as necessary, the position at which the hook  113  is coupled to the hole  130 . 
       FIG. 7A  is a cross-sectional view illustrating a state in which the plug member  110  and the socket member  120  are separated from each other, and  FIG. 7B  is a cross-sectional view of a coupled state. As described above, the buckle according to the present disclosure is coupled as the plug member  110  provided on the strap S 1  is directly coupled to the socket member  120 . The plug member  110  and the socket member  120  are strongly attached and coupled to each other by magnetic force of the first and second magnets  116  and  123  as the coupling protruding portions  115  of the plug member  110  are inserted into the coupling groove  121  of the socket member  120 . 
     The coupling protruding portions  115  of the plug member  110  are attracted and inserted into the coupling groove  121  by strong magnetic force of the first and second magnets  116  and  123  even when the plug member  110  approaches the vicinity of the socket member  120 . 
     To separate the plug member  110  and the socket member  120 , the buckle is separated as the coupling protruding portions  115  are withdrawn from the coupling groove  121  only by lifting up a free end of the strap S 1  by applying small force, that is, force greater than attachment force of the first and second magnets  116  and  123 . 
     As described above, the buckle is simply separated by lifting the plug member  110  directly upward with respect to the socket member  120  by using the tip portion of the strap S 1 . However, in a case in which pressure is applied in an abnormal direction, that is, in a lateral direction due to external contact, the buckle is not easily separated since the coupling protruding portions  115  are inserted into the coupling groove  121 . Further, the hook groove  124  is formed to intersect the intermediate portion of the coupling groove  121 , and multiple surfaces are connected to one another as the hook  113  is coupled to the hook groove  124 , and as a result, the plug member and the socket member are not easily separated in the directions other than the directly upward direction. 
       FIG. 9  is a perspective view illustrating a state in which a plug member and a socket member of another type of buckle according to the present disclosure correspond to each other,  FIG. 10  is an exploded bottom perspective view of  FIG. 9 , and  FIG. 11  is a bottom perspective view of the plug member illustrated in  FIG. 9 . Referring to  FIGS. 9 to 11 , the outer circumferential edge of the hook  113  does not protrude outward from the coupling protruding portions  115  when the hook  113  is fitted with the cross bar  112 . Therefore, the coupling groove  121  of the socket member  120 , which accommodates the coupling protruding portions  115 , may be organized in a simpler form, and the hook groove  124  described in the exemplary embodiment may not be provided. 
     In addition, a circumferential edge portion  128  is formed to protrude at an outer circumferential edge of the coupling groove  121  of the socket member  120 , such that the outer sheath of the bag is organized so as not to move over the coupling groove  121  when the wing portion  122  is installed in the outer sheath of the bag, and as a result, the operation may be easily and accurately performed. 
       FIG. 12  is an exploded perspective view illustrating a modified example of the buckle according to the present exemplary embodiment, and  FIG. 13  is a coupled perspective view thereof. Referring to  FIGS. 12 and 13 , catching grooves  117  are formed in lateral surfaces of the coupling protruding portions  115  of the plug member  110 , protruding portions  125  are formed so as to face one another at both sides of the coupling groove  121  of the socket member  120 , and catching protrusions  126  protrude from inner surfaces of the protruding portions  125  so as to face one another. 
     Therefore, when the coupling protruding portions  115  are inserted into the coupling groove  121 , the catching protrusions  126  are caught by the catching grooves  117  of the coupling protruding portions  115  while the coupling protruding portions  115  are strongly inserted by magnetic force of the magnets, and as a result, the coupled state of the plug member  110  and the socket member  120  may be more securely maintained by magnetic force of the magnets. 
     An inclined surface  127  is formed on an upper surface of each of the catching protrusions  126  so that the coupling protruding portion  115  may be more easily inserted, and a curved or inclined surface may also be formed at an upper or lower end of the catching groove  117  so that the catching protrusion  126  is smoothly connected. 
     The coupling protruding portions  115  may be easily inserted into the coupling groove  121  by magnetic force while being guided by the inclined surfaces  127 , and the plug member  110  may be separated from the socket member  120  by applying small force. 
     The catching protrusion  126  may also be formed on an inner surface of the coupling groove  121 . 
     According to the exemplary embodiment of the present disclosure as described above, a stably coupled state of the plug member  110  and the socket member  120  may be maintained, and the intended separation may be conveniently performed. 
       FIGS. 14 to 19  illustrate a second exemplary embodiment of the present disclosure. 
       FIG. 14  is an exploded perspective view of a buckle according to the second exemplary embodiment of the present disclosure,  FIG. 15  is a bottom perspective view of a socket member,  FIG. 16  is a lateral side view illustrating a coupled state of the buckle according to the present disclosure, and  FIG. 17  is a view illustrating a state in which the buckle is installed and used. Similar to the first exemplary embodiment, a buckle  200  according to the present exemplary embodiment broadly includes a plug member  210  and a socket member  220 . 
     The plug member  210  has the same configuration as the plug member  110  according to the first exemplary embodiment. The plug member  210  includes a frame  211  which has a loop shape, a cross bar  212  which traverses a lower intermediate side of the frame  211 , and a hook  213  which is coupled to an intermediate portion of the cross bar  212 . 
     A strap is interposed between the frame  211  and the cross bar  212 . As illustrated in  FIG. 14 , a strap S 2  enters the frame  211  from a lower side of the frame  211 , travels over an upper side of the cross bar  212 , and exits the frame  211  from an opposite lower side of the frame. Central portions of lateral portions of the frame  211  extend downward and the cross bar  212  is formed at lower ends of the central portions so that the strap may be smoothly interposed, and as a result, the cross bar  212  is positioned to further protrude downward in comparison with a circumferential edge portion of the frame  211 . 
     Coupling protruding portions  215  are formed at both sides of the cross bar  212 . The coupling protruding portion  215  may have a quadrangular cross section, and a first magnet  216  is embedded in a lower surface of the coupling protruding portion  215 . 
     A recessed portion is formed in the intermediate portion of the cross bar  212  as the coupling protruding portions  215  are formed at both sides, and the hook  213  is installed in the recessed portion. 
     The hook  213  is fitted to be wound around the cross bar  212  so that the hook  213  is rotated about the cross bar  212 . A tip portion of the hook  213  is elongated and inserted into a hole  230  formed in the strap S 2 , such that the hook  213  is fastened to the strap S 2 . 
     A catching projection  214  is formed at an intermediate portion of the hook  213 . When the hook  213  is inserted into the hole  230  of the strap S 2 , the catching projection  214  prevents the tip portion of the hook  213  from excessively protruding while penetrating the strap S 2 . 
     The socket member  220  is formed in a thin plate shape. Four guide protruding portions  225  protrude from an upper surface of the socket member  220  so as to be spaced apart from one another, such that a coupling groove  221  is formed between the guide protruding portions  225 . 
     A hook groove  224 , which intersects, at a right angle, an intermediate portion of the coupling groove  221 , is formed in the intermediate portion of the coupling groove  221 , such that a “+” shaped groove is provided as a whole. 
     That is, the coupling groove  221  is formed as the surface of the socket member  220  protrudes. 
     The coupling protruding portions  215  of the plug member  210  are inserted into the coupling groove  221 , and a second magnet  223  is embedded in a bottom surface of the coupling groove  221 . 
     Further, the hook  213 , which protrudes laterally, is accommodated in the hook groove  224  when the coupling protruding portions  215  of the plug member  210  are inserted. 
     As illustrated in  FIG. 15 , a portion in which the second magnet  223  is embedded protrudes from a bottom surface of the socket member  220 . 
     As illustrated in  FIG. 16 , the plug member  210  and the socket member  220  remain coupled by magnetic force as the coupling protruding portions  215  of the plug member  210  are inserted into the coupling groove  221  of the socket member  220 . 
     The socket member  220  is embedded at one end of a bag body B 2 . To this end, a circumferential edge portion of the upper surface of the socket member  220  is formed to have a flat surface and extends to form a wing portion  222 . The wing portion  222  is attached to an outer sheath that defines the bag body B 2 . 
     As illustrated in  FIG. 17 , the wing portion  222  of the socket member  220  is coupled, by sewing, to the outer sheath of the bag body B 2  in a state in which the guide protruding portions  225  and the coupling groove  221  are exposed. Alternatively, the wing portion  222  may be fixedly attached by a bonding agent. Reference numeral ‘240’ indicates a sewed line. 
     The movements of the coupling protruding portions  215  are prevented as the hook  213 , which further protrudes laterally than the coupling protruding portions  215 , is coupled to the hook groove  224  when the coupling protruding portions  215  and the hook  213  are coupled. Further, the coupling protruding portions  215  are prevented from being withdrawn laterally from the coupling groove  221  opened laterally, thereby maintaining a more stably coupled state. 
     That is, when an unintentional action, such as external contact, of separating the buckle occurs, a drawback of the coupling groove  221  opened laterally is solved since the hook  213  is coupled to the hook groove  224  which extends while intersecting the intermediate portion of the coupling groove  221 , thereby preventing abnormal withdrawal of the plug member  210 . 
     In the present disclosure configured as described above, the socket member  220  is embedded at one end of the bag body B 2 , the strap S 2  connected to the flap F 2  is inserted into the frame  211  of the plug member  210 , and the hook  213  is inserted into and connected to the hole  230 . 
     The multiple holes  230  are formed at predetermined intervals in the strap S 2 , and as a result, it is possible to adjust a position of the plug member  210  by changing, as necessary, the position at which the hook  213  is coupled to the hole  230 . 
     The buckle according to the present disclosure is coupled as the plug member  210  installed on the strap S 2  is coupled directly to the socket member  220 , and the coupling protruding portions  215  of the plug member  210  are strongly attached and coupled to the coupling groove  221  of the socket member  220  by magnetic force of the first and second magnets  216  and  223  while being inserted into the coupling groove  221  of the socket member  220 . 
     The coupling protruding portions  215  of the plug member  210  are attracted and inserted into the coupling groove  221  by strong magnetic force of the first and second magnets  216  and  223  even when the plug member  210  approaches the vicinity of the socket member  220 . 
     Here, an upper end portion of each of the guide protruding portions  225  may be formed to have a curved surface so that the coupling protruding portion  215  is smoothly inserted. 
     To separate the plug member  210  and the socket member  220 , the buckle is separated as the coupling protruding portions  215  are withdrawn from the coupling groove  221  only by lifting up a free end of the strap S 2  by applying small force, that is, force greater than attachment force of the first and second magnets  216  and  223 . 
     As described above, the buckle is simply separated by lifting the plug member  210  directly upward with respect to the socket member  220  by using the tip portion of the strap S 2 . However, in a case in which pressure is applied in an abnormal direction, that is, in a lateral direction due to external contact, the plug member and the socket member are not easily separated in the directions other than the directly upward direction since the coupling protruding portions  215  and the hook  213  are in contact with the guide protruding portions  225  in all directions. 
       FIG. 18  is an exploded perspective view illustrating a modified example of the buckle according to the present exemplary embodiment, and  FIG. 19  is a coupled perspective view thereof. Referring to  FIGS. 18 and 19 , catching grooves  217  are formed in lateral surfaces of the coupling protruding portions  215  of the plug member  210 , and catching protrusions  226  protrude, so as to face one another, from inner surfaces of the guide protruding portions  225  of the socket member  220  which face one another. 
     Therefore, when the coupling protruding portions  215  are inserted into the coupling groove  221 , the catching protrusions  226  are caught by the catching grooves  217  of the coupling protruding portions  215  while the coupling protruding portions  115  are strongly inserted by magnetic force of the magnets, and as a result, the coupled state of the plug member  210  and the socket member  220  may be more securely maintained by magnetic force of the magnets. 
     An inclined surface  227  is formed on an upper surface of each of the catching protrusions  226  so that the coupling protruding portion  215  may be more easily inserted, and a curved or inclined surface may also be formed at an upper or lower end of the catching groove  217  so that the catching protrusion  226  is smoothly connected. 
     The coupling protruding portions  215  may be easily inserted into the coupling groove  221  by magnetic force while being guided by the inclined surfaces  227 , and the plug member  210  may be separated from the socket member  220  by applying small force. 
     According to the exemplary embodiment of the present disclosure as described above, a stably coupled state of the plug member  210  and the socket member  220  may be maintained, and the intended separation may be conveniently performed. 
     The present disclosure described and illustrated above is not intended as being limited to the exemplary embodiments, and the present disclosure may be applied and modified in various forms without departing from the subject matter of the present disclosure. For example, according to the present disclosure, the shape of the coupling protruding portion, the shape of the coupling groove, and the number and shape of the guide protruding portion may be arbitrarily selected as necessary. 
     From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.