Patent Publication Number: US-2017362865-A1

Title: Hinged door fixing apparatus for preventing hinged door from being automatically closed

Description:
TECHNICAL FIELD 
     The present invention relates to a hinged door fixing apparatus and, more particularly, to an apparatus for fixing a hinged door to prevent a hinged door that is generally used at home from accidentally slamming shut. 
     BACKGROUND ART 
     In general, hinged doors that are pushed/pulled to open/close are generally used for convenience in homes except for the doors to relatively small spaces such as multipurpose rooms and a storage rooms for keeping various items, including a sub-door of a front door. 
     When a hinged door is opened, it may hit the wall on the opposite side and the door knob or the edge of the door may be damaged, so recently buffers are attached to the side of the hinged door that hits a wall. 
     Such buffers, in order to prevent damage to a door knob, have a support rod protruding further than the door knob and a buffer ball mounted at the end of the support rod to absorb shock. Further, the buffers are disposed at the upper portion of hinged doors so that they are not damaged by users even though they are used for long period of time. 
     Hinged doors with a safety device such as the above-described buffers are frequently accidentally slammed shut by wind from the outside when windows are open for cleaning of ventilating. 
     Accordingly, users use specific objects for supporting hinged doors or objects inserted between the doors and the floor to prevent this problem, but the users have to manually install such objects in this case. 
     DISCLOSURE 
     Technical Problem 
     An object of the present invention is to provide a hinged door fixing apparatus for preventing a hinged door that is used at home from slamming shut due to wind blowing inside from the outside. 
     Technical Solution 
     In order to achieve the objects of the present invention, a hinged door fixing apparatus according to an embodiment of the present invention includes a base and a holder. 
     The base may be fixed to a wall to come in contact with a buffer having a buffer ball at an end and mounted on a hinged door when the hinged door opens, in order to prevent a doorknob or an edge of the hinged door from directly hitting against the wall when the hinged door opens. The holder may be combined with the base and instantaneously and elastically holds the buffer ball when the buffer hits against the base. 
     In order to achieve the objects of the present invention, a hinged door fixing apparatus, which is mounted on a wall to hold a buffer having a buffer ball at an end thereof and mounted on a hinged door to prevent a doorknob or an edge of the hinged door from directly hitting against the wall when the hinged door opens, includes first and second holding bars, an elastic module, and support members. 
     The first and second holding bars may be vertically spaced from each other with a predetermined gap to insert the buffer ball therebetween. The elastic module may be disposed between the first and second holding bars and may provide elasticity to insert and fix the buffer ball between the first and second holding bars. The support members may be disposed at both ends of the first and second holding bars so that the gap between the first and second holding bars is adjusted by the elastic module. The support members each may have: a first support plate having a first cam groove in which a first cam follower coupled to an end of the first holding bar is inserted; and a second support plate having a second cam groove that has a symmetric structure to the first cam groove and in which a second cam follower coupled to an end of the second holding bar is inserted. 
     In order to achieve the objects of the present invention, a hinged door fixing apparatus, which is mounted on a wall to hold a buffer having a buffer ball at an end thereof and mounted on a hinged door to prevent a doorknob or an edge of the hinged door from directly hitting against the wall when the hinged door opens, includes a housing plate, a pair of rollers, roller support members, and elastic members. 
     The housing plate may have a receiving groove defined by a bottom and sides and may have an inlet formed through the bottom to insert and pull out the buffer ball. The rollers may be disposed to face each other at the inlet in the receiving groove to hold the buffer ball that is inserted and pulled out. The roller support members may be respectively coupled to and cover both ends of the rollers such that the rollers can rotate in the receiving groove. The elastic members may provide elasticity to the roller support members between the roller support members and inner sides of the receiving groove. 
     Advantageous Effects 
     According to the present invention, in order to prevent the doorknob or the edge of a hinged door from directly hitting against a wall when the hinged door opens, the buffer ball at the end of the buffer mounted on the hinged door is elastically and instantaneously held by the holder combined with the base fixed to the wall, so even though a user simply opens the hinged door, it is possible to prevent the hinged door from slamming shut due to wind from the outside. 
     Accordingly, the possibility of a user being surprised or injured by the hinged door slamming shut is precluded, so the user can more safely use the hinged door. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view schematically showing a hinged door fixing apparatus according to an embodiment of the present invention. 
         FIG. 2  is a view showing in detail a holder of the hinged door fixing apparatus shown in  FIG. 1 . 
         FIG. 3  is a view schematically showing a hinged door fixing apparatus according to another embodiment of the present invention. 
         FIG. 4  is a perspective view schematically showing a hinged door fixing apparatus according to another embodiment of the present invention. 
         FIG. 5  is a cross-sectional view of a holding block of the hinged door fixing apparatus shown in  FIG. 4 . 
         FIG. 6  is a view schematically showing an interior space where a hinged door fixing apparatus according to another embodiment of the present invention is installed. 
         FIG. 7  is a view showing in detail the hinged door fixing apparatus shown in  FIG. 6 . 
         FIG. 8  is a view showing in detail first and second cam grooves of the hinged door fixing apparatus shown in  FIG. 7 . 
         FIGS. 9 to 13  are views showing in stages a process of fixing a buffer ball to a hinged door fixing apparatus. 
         FIG. 14  is a view schematically showing an interior space where a hinged door fixing apparatus according to another embodiment of the present invention is installed. 
         FIG. 15  is a view showing in detail the hinged door fixing apparatus shown in  FIG. 14 . 
         FIG. 16  is a view showing in detail the internal structure of a housing plate of the hinged door fixing apparatus shown in  FIG. 15 . 
         FIG. 17  is a view showing the structure of the housing plate shown in  FIG. 16  without rollers, roller supports, and elastic members. 
         FIG. 18  is a view showing in detail a cover plate for covering the housing plate of the hinged door fixing apparatus shown in  FIG. 15 . 
         FIG. 19  is a view showing in detail a fixing plate coupled to the cover plate of the hinged door fixing apparatus shown in  FIG. 15 . 
     
    
    
     BEST MODE 
     Hereinafter, hinged door fixing apparatuses for preventing a hinged door from being automatically closed according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may be modified in various ways and implemented by various exemplary embodiments, so that specific exemplary embodiments are shown in the drawings and will be described in detail. However, it should be understood that the present invention is not limited to the specific exemplary embodiments, but includes all modifications, equivalents, and substitutions included in the spirit and the scope of the present invention. Like reference numerals are given to like components in the description of the drawings. The sizes of the structures shown in the drawings are enlarged relatively to the real sizes to make the present invention clear. 
     Terms used in the specification, ‘first’, ‘second’, etc., may be used to describe various components, but the components are not to be construed as being limited to the terms. The terms are used to distinguish one component from another component. For example, the ‘first’ component may be named the ‘second’ component, and vice versa, without departing from the scope of the present invention. 
     Terms used in the present specification are used only in order to describe specific exemplary embodiments rather than limiting the present invention. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the terms “comprises”, “comprising”, “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. It must be understood that the terms defined by the dictionary are identical with the meanings within the context of the related art, and they should not be ideally or excessively formally defined unless the context clearly dictates otherwise. 
       FIG. 1  is a perspective view schematically showing a hinged door fixing apparatus according to an embodiment of the present invention and  FIG. 2  is a view showing in detail a holder of the hinged door fixing apparatus shown in  FIG. 1 . 
     Referring to  FIGS. 1 and 2 , a hinged door fixing apparatus  100  according to an embodiment of the present invention includes a base  200  and a holder  300 . 
     The base  200  is fixed to a wall  20  that a hinged door  10  hits against when opening. A buffer  30  is mounted on the hinged door  10  to prevent the doorknob or the edge of the hinged door  10  from directly hitting against the wall  20  when the hinged door  10  opens. The buffer  30  includes a support rod  32  protruding further than the doorknob and a buffer ball  34  mounted at the end of the support rod  32  to absorb shock. The buffer ball  34  may be made of rubber having excellent shock-absorbing ability relative to the price. 
     The base  200 , in detail, is fixed at the position where the buffer  30  comes in contact on the wall  20  when the hinged door  10  opens. Appropriate fasteners may be used for the base  200 , depending on the material of the wall  20 . For example, for the base  200 , anchor pieces or concrete screws may be used when the wall  20  is made of cement, while drill pieces for wood or treenails may be used when the wall is made of wood. Unlikely, the base  200  may be integrally formed with the wall  20  in the process of manufacturing the wall  20 . 
     The holder  300  is combined with the base  200 . The holder  300  elastically and instantaneously holds the buffer ball  32  when the buffer  30  hits against the base  200 . To this end, the holder  300  includes holding bars  310 , guides  320 , and elastic members  330 . 
     Two holding bars  310  are spaced from each other to make a space for inserting the buffer ball  34  therebetween. In the holding bars  310 , the surfaces that the buffer ball  34  comes in contact with when being inserted between the holding bars  310  may be curved to be able to smoothly guide the holding bars  310  that are inserted. Accordingly, the holding bars  310  may have a cylindrical shape. The two holding bars  310  have the same function, so they may have substantially the same shape. 
     The guides  320  are disposed between the holding bars  310  and the base  200 . The guides  320  guide the holding bars  310  so that the space between the holding bars  310  is opened and closed when the buffer ball  34  is inserted into the space. Accordingly, the guides  320  may be hinged to the base  200  to smoothly guide the holding bars  310 . 
     The guides  320 , as shown in  FIG. 2 , may have a structure that simply connects the holding bars  310  and the base  200  in the shape of a plate, but may have a fan shape that covers the holding bars  310  or has coupling holes for coupling both ends of the holding bars  310 . 
     The elastic members  330  are attached to the guides  320 . The elastic members  330  are provided to apply elasticity to the holding bars  310  to close the holding bars  310 . Accordingly, the elastic members  330  may be rubber bands or springs connected between the guides  320  connected with the holding bars  310 , respectively. 
     As described above, in order to prevent the doorknob or the edge of the hinged door  10  from directly hitting against the wall  20  when the hinged door  10  opens, the buffer ball  34  at the end of the buffer  30  mounted on the hinged door  10  is elastically and instantaneously held by the holder  300  combined with the base  200  fixed to the wall  20 , so even though a user simply opens the hinged door  10 , it is possible to prevent the hinged door  10  from slamming shut due to wind from the outside. 
     Accordingly, the possibility of a user being surprised or injured by the hinged door  10  slamming shut is precluded, so the user can more safely use the hinged door  10 . 
       FIG. 3  is a view schematically showing a hinged door fixing apparatus according to another embodiment of the present invention. 
     This embodiment is substantially the same as the apparatus shown in  FIGS. 1 and 2  except for the shape of the base, the structure of the holding bars, and the buffer corresponding to them, so the same configuration is not described in detail. 
     Referring to  FIG. 3 , the base  500  of a hinged door fixing apparatus  400  according to another embodiment of the present invention has a housing structure. Accordingly, a holder  600  is disposed in the housing. Since the base  500  has a housing structure, a simple external design can be achieved. 
     The base  500  has an insertion hole  510  in which the buffer ball ( 34  in  FIG. 1 ) of the buffer ( 30  in  FIG. 1 ) is inserted and holding bars  610  of the holder  600  are partially exposed. The insertion hole  510  may be structurally stably formed at the center of the base  500 . 
     The gap between the holding bars  610  of the holder  600  may be decreased, as it goes to any side. According to this configuration, when the buffer ball ( 34  in  FIG. 1 ) is inserted between the holding bars  610 , it is guided in the space between the holding bars  610  by the narrowing shape, so it can be stably inserted and held. 
     Further, the narrowing direction of the gap between the holding bars  610  may be set in the inflow direction of wind W. According to this configuration, the buffer ball ( 34  in  FIG. 1 ) can be more easily and stably inserted and held in the space between the holding bars  610 . When the holding bars  610  are arranged such that the gap narrows in the inflow direction of wind W from the outside, the buffer ball ( 34  in  FIG. 1 ) is guided into the narrowing part between the holding bars  610 , so the buffer ball ( 34  in  FIG. 1 ) can be more stably held by the holding bars  610 . The buffer ( 30  in  FIG. 1 ) is designed to allow the buffer ball ( 34  in  FIG. 1 ) to move in the inflow direction of the wind W so that the buffer ball ( 34  in  FIG. 1 ) is guided into the narrowing part between the holding bars  610  by the wind W, whereby the buffer ball ( 34  in  FIG. 1 ) can be more stably held by the wind W. 
       FIG. 4  is a perspective view schematically showing a hinged door fixing apparatus according to another embodiment of the present invention and  FIG. 5  is a cross-sectional view of a holding block of the hinged door fixing apparatus shown in  FIG. 4 . 
     Referring to  FIGS. 4 and 5 , a hinged door fixing apparatus  700  according to another embodiment of the present invention includes a holding block  800  and at least one ball plunger  900 . 
     The holding block  800  may be fixed to the wall  20 , as an integral structure with the base ( 200  in  FIG. 1 ) in the embodiment shown in  FIGS. 1 and 2 . The holding block  800  has an insertion hole  810  into which a buffer ball  34  of a buffer  30  mounted on the hinged door  10  is inserted. Accordingly, the holding block  800  may have a height larger than the diameter of the buffer ball  34  so that the buffer ball  34  can be fully inserted therein. 
     The ball plungers  900  are arranged inside the insertion hole  810  of the holding block  800 . The ball plungers  900  each include a ball  910  partially protruding toward the insertion hole  810  and a spring  920  disposed inside the ball  910  and elastically pushing the ball  910  such that the ball  910  is exposed inside the insertion hole  810 . 
     Accordingly, when the hinged door  10  opens, the buffer ball  34  can be inserted into the insertion hole  810  and simply held by elasticity of the ball plunger  900 . The plungers  900  are arranged with regular intervals around and inside the insertion hole  810 , so it is possible to more stably hold the buffer ball  34 . The number of the ball plungers  900  substantially has a relationship with the force that inserts the buffer ball  34  and the force for holding the buffer ball  34 , so the number can be determined in consideration of the relationship, depending on the installation conditions of the hinged door  10 . 
     As described above, since the buffer ball  34  is held in the holding block  800  having the ball plungers  900  and the insertion hole  810 , it is possible to simply prevent the hinged door  10  from slamming shut. Further, there is an additional advantage that the external appearance is simple through the one block and the possibility of the apparatus breaking down is relatively low. 
       FIG. 6  is a view schematically showing an interior space where a hinged door fixing apparatus according to another embodiment of the present invention is installed,  FIG. 7  is a view showing in detail the hinged door fixing apparatus shown in  FIG. 6 , and  FIG. 8  is a view showing in detail first and second cam grooves of the hinged door fixing apparatus shown in  FIG. 7 . 
     Referring to  FIGS. 6 to 8 , a hinged door fixing apparatus  100   a  according to another embodiment of the present invention is mounted on a wall  30   a  of an interior space  20   a  to hold a buffer  50   a  having a buffer ball  40   a  at the end and mounted at the upper end of the hinged door  10   a , in order to prevent the doorknob or the edge of the hinged door  10   a  from directly hitting against the wall  30   a  when the hinged door  10   a  opens. The hinged door fixing apparatus  100   a  includes first and second holding bars  200   a  and  300   a , an elastic module  400   a , and support members  500   a.    
     The first and second holding bars  200   a  and  300   a  are vertically spaced with a gap so that the buffer ball  40   a  is inserted therebetween. Since the buffer ball  40   a  is made of rubber having a shock-absorbing ability, the first and second holding bars  200   a  and  300   a  can naturally freely rotate to reduce friction by the buffer ball  40   a.    
     The elastic module  400   a  is disposed between the first and second holding bars  200   a  and  300   a . The elastic module  400   a  provides elasticity to insert and fix the buffer ball  40   a  between the first and second holding bars  200   a  and  300   a . Further, the elastic module  400   a  may be disposed between the first and second holding bars  200   a  and  300   a  to adjust the gap between the holding bars while the buffer ball  40   a  is inserted and fixed. 
     To this end, the elastic module  400   a  may include reference rods  410   a , first blocks  420   a , second blocks  430   a , and elastic members  440   a . The reference rods  410   a  are vertically disposed at both ends of the first and second holding bars  200   a  and  300   a . The first blocks  420   a  are coupled to both ends of the first holding bar  200   a  and fitted on the reference rods  410   a  to be able to vertically move. In detail, the first blocks  420   a  each may have a first hole  422   a  at the center, through which the reference rod  410   a  passes, to move on the reference rod  410   a . The second blocks  420   a  are, similar to the first blocks  420   a , coupled to both ends of the second holding bar  300   a  and fitted on the reference rods  410   a  to be able to vertically move. In detail, similar to the first blocks  420   a , the second blocks  430  each may have a second hole  432   a  through which the reference rod  410   a  passes. The elastic members  440   a  are disposed between the first and second blocks  420   a  and  430 . The elastic members  440   a  provide elasticity between the first and second blocks  420   a  and  430   a . In detail, the elastic members  440   a  may be extension springs and may be coupled to the first and second blocks  420   a  and  430   a , with the reference rods  410   a  passing through them, to provide force that enables the first and second holding bars  200   a  and  300   a  to fix the buffer ball  40   a.    
     In this embodiment, although the first and second blocks  420   a  and  430   a  are fitted on the reference rods  410   a  to be able to vertically move, the reference rods  410   a  may have a structure that can telescopically adjust its length with the first and second blocks  420   a  and  430   a  fixed to the reference rods  410   a.    
     The support members  500   a  are coupled to both ends of the first and second holding bars  200   a  and  300   a  and support them so that the gap between the first and second holding bars  200   a  and  300   a  is adjusted by the elastic modules  400   a.    
     The support members  500   a  may have a structure that supports the first and second holding bars  200   a  and  300   a  in a cam type to reduce elastic resistance from the elastic module  400   a  while the buffer ball  40   a  is inserted or pulled out. 
     In detail, the support members  500   a  each have a first support plate  510   a  having a first cam groove  511   a  in which a first cam follower  210   a  coupled to the end of the first holding bar  200   a  is inserted and a second support plate  520   a  having a second cam groove  521   a  that has a symmetric structure to the first cam groove  511   a  and in which a second cam follower  310   a  coupled to the end of the second holding bar  300   a  is inserted. 
     The first and second cam grooves  511   a  and  512   a , in order to reduce the elastic resistance, as in  FIG. 3 , may have: first cam passages  512   a  that guide respectively the first and second cam followers  210   a  and  310   a  such that the first and second holding bars  200   a  and  300   a  open until the first and second holding bars  200   a  and  300   a  reach the center of the buffer ball  40   a  in the entering direction of the buffer ball  40   a ; second cam passages that continue from the first cam passages  512   a  and guide respectively the first and second cam followers  210   a  and  310   a  such that the first and second holding bars  200   a  and  300   a  close to hold the buffer ball  40   a  passing over the center; and third cam passages  514   a  that are connected to the starts of the first cam passages  512   a  from the ends of the second cam passages  513   a  and guide respectively the first and second cam followers  210   a  and  310   a  such that the first and second holding bars  200   a  and  300   a  open in the pulling-out direction of the buffer ball  40   a.    
     The support members  500   a  each may further have an anti-reversing member  530   a  that is disposed at the joint between the third cam passage  514   a  and the first cam passage  512   a  to prevent the first cam follower  210   a  and the second cam follower  301   a  from being guided into the third cam passage  514   a  when the buffer ball  40   a  is inserted. Therefore, according to the hinged door fixing apparatus  100   a , when the buffer ball  40   a  is inserted, the first and second cam followers  210   a  and  310   a  are guided into the third cam passages  514   a , so the elastic resistance is further increased and it is possible to preclude the inconvenience of a user having to apply a large force. 
     Meanwhile, in order to adjust the gap between the first and second holding bars  200   a  and  300   a  when the size of the buffer ball  40   a  is changed, the support members  500   a  may each further have a fixing element  540   a  that couples the second support plate  520   a  to the first support plate  510   a  such that the second support plate  520   a  can vertically move, and fixes the second plate  520   a  at a desired position on the first support plate  510   a . The fixing element  540   a  may simply fix the second support plate  520   a  in a push button type or a bolt type manner. Further, an insertion groove  515   a  in which the second support plate  520   a  is inserted may be formed on the first support plate  510   a  to prevent the second support plate  520   a  that vertically moves from protruding toward the first and second holding bars  200   a  and  300   a . Further, a rail  516   a  may be disposed in the insertion groove  515   a  to allow the second support plate  520   a  to vertically move. 
     As described above, the first and second holding bars  200   a  and  300   a  are guided along the first and second cam grooves  511   a  and  521   a  shown in  FIG. 3 , with the elastic module  400   a  therebetween, thereby receiving and fixing the buffer ball  40   a  coupled to the end of the buffer  50   a  mounted at the upper end of the hinged door  10   a , so that it is possible to minimize elastic resistance that is generated when the buffer ball  40   a  is fixed in or separated out of the hinged door fixing apparatus  100   a . Therefore, a user can more naturally fix the buffer ball  40   a  in the hinged door fixing apparatus  100   a  without general inconvenience. 
     Hereinafter, the process of the buffer ball  40   a  being inserted into or pulled out of the gap between the first and second holding bars  200   a  and  300   a  is described in detail with reference to  FIGS. 9 to 13 . 
       FIGS. 9 to 13  are views showing in stages a process of fixing a buffer ball to a hinged door fixing apparatus. 
     Referring to  FIG. 9 , in order to insert and fix the buffer ball  40   a , the buffer ball  40   a  is prepared to be inserted between the first and second holding bars  200   a  and  300   a.    
     Referring to  FIG. 10 , when a user applies a force that pushes the buffer ball  40   a , the first and second cam followers  210   a  and  310   a  coupled to the first and second holding bars  200   a  and  300   a , respectively, are guided along the first cam passages  512   a  and the first and second holding bars  200   a  and  300   a  naturally open. 
     Referring to  FIG. 11 , when the first and second holding bars  200   a  and  300   a  pass over the center of the buffer ball  40   a , the first and second cam followers  210   a  and  310   a  are guided along the second cam passages  513   a  and the first and second holding bas  200   a  and  300   a  close and more strongly fix the rear portion of the buffer ball  40   a.    
     Referring to  FIG. 12 , when a user intends to separate the buffer ball  40   a  from the first and second holding bars  200   a  and  300   a , the first and second cam followers  210   a  and  310   a  are guided along the third cam passages  514   a  and the first and second holding bars  200   a  and  300   a  naturally open. 
     Referring to  FIG. 13 , when the cam followers  210   a  and  310   a  pass the joints between third cam passages  514   a  and the second cam passages  513   a  while the buffer ball  40   a  is separated from the first and second holding bars  200   a  and  300   a , the anti-reversing members  530   a  are instantaneously opened and then closed, so even if the buffer ball  40   a  is inserted back into the gap between first and second holding bars  200   a  and  300   a , the first and second cam followers  210   a  and  310   a  can be prevented from being guided into the third cam passages  514 . 
       FIG. 14  is a view schematically showing an interior space where a hinged door fixing apparatus according to another embodiment of the present invention is installed,  FIG. 15  is a view showing in detail the hinged door fixing apparatus shown in  FIG. 14 ,  FIG. 16  is a view showing in detail the internal structure of a housing plate of the hinged door fixing apparatus shown in  FIG. 15 , and  FIG. 17  is a view showing the structure of the housing plate shown in  FIG. 16  without rollers, roller supports, and elastic members. 
     Referring to  FIGS. 14 to 17 , a hinged door fixing apparatus  100   b  according to another embodiment of the present invention is mounted on a wall  30   b  of an interior space  20   a  to hold a buffer  50   b  having a buffer ball  40   b  at the end and mounted at the upper end of a hinged door  10   b , in order to prevent the doorknob or the edge of the hinged door  10   b  from directly hitting against the wall  30   b  when the hinged door  10   b  opens. The hinged door fixing apparatus  100   b  includes a housing plate  200   b , a pair of rollers  300   b , a pair of roller support members  400   b , and at least a pair of elastic members  500   b.    
     The housing plate  200   b  has a receiving groove  230   b  defined by a bottom  210   b  and sides  220   b  protruding from the edge of the bottom  210   b . The housing plate  200   b  has an inlet  212   b  formed through the bottom  210   b  to insert and pull out the buffer ball  40   a . Since the buffer ball  40   b  has a circular structure, the inlet  212   b  may have a circular or an elliptical structure having a diameter larger by a predetermined size than the buffer ball  40   b.    
     The rollers  300   b  are circular rods or tubes and disposed laterally in the receiving groove  230   b . In detail, the rollers  300   b  may be disposed to face each other at the inlet  212  to hold the buffer ball  40   b  being inserted and pulled out. The rollers  300   b  may be arranged in parallel with each other, but if necessary, they may be arranged to narrow in any one direction. The rollers  300   b  may be made of metal having high strength not to be damaged by the buffer ball  40   b  that is repeatedly inserted and pulled out. 
     The roller support members  400   b  are disposed in the receiving groove  230   b . In detail, the roller support members  400   b  may be coupled to and cover both ends of the rollers  300   b , respectively, such that the rollers  300   b  can rotate. The roller support members  400   b  may almost contact with the inner sides  220   b  facing each other of the receiving groove  230   b  of the housing plate  200   b  to stably guide the rollers  300   b  when the buffer ball  40   b  is inserted and pulled out through the inlet  212 . The roller support members  400   b  are, similar to the rollers  300   b , directly operated when the buffer ball  40   b  is repeatedly inserted and pulled out, so they may be made of metal having high strength. 
     The elastic members  500   b  are disposed respectively between the roller support members  400   b  and the inner sides  220   b  of the receiving groove  230   b . The elastic members  500   b  provide elasticity so that the rollers  300   b  can hold the buffer ball  40   b  that is inserted and pulled out. For example, the elastic members  500   b  may be compression springs. It should be understood that the tension and the number of the elastic members  500   b  that are the compression springs can be freely changed, depending on the installation space and the size of the buffer ball  40   b.    
     As described above, in the structure composed of the rollers  300   b , the roller support members  400   b , and the elastic members  500   b , the housing plate  200   b  may further include stoppers  240   b  for stopping the roller support members  400   b  so that the rollers  300   b  are maintained with a predetermined gap therebetween in the receiving groove  230   b . The stoppers  240   b  may be formed on the bottom of the receiving groove  230   b  for the structure of the roller support members  400   b  described above. In detail, the stoppers  230   b  may protrude from the bottom  210   b , inside the roller support members  400   b , as shown in  FIGS. 16 and 17 . 
     Further, the housing plate  200   b  may have guide grooves  250   b  on the bottom  210   b  to naturally guide the elastic members  500   b  that are compression springs when the roller support members  400   b  are operated by the buffer ball  40   b  that is repeatedly inserted and pulled out. 
     As described above, the buffer ball  40   b  coupled to the end of buffer  50   b  mounted at the upper end of the hinged door  10   b  to prevent the doorknob or the edge of the hinged door  10   b  from directly hitting against the wall  30   b  when the hinged door  10   b  opens is held by the pair of rollers  300   b  rotatably coupled to the roller support members  400   b  and receiving elasticity from the elastic members  500   b . Accordingly, it is possible to minimize the friction when the buffer ball  40   b  is inserted and pulled out, through the rotatable structure of the rollers  300   b . Therefore, as the friction is minimized, a user can more easily fix/separate the hinged door  10   b  to/from the wall  30   b.    
     Further, since the stoppers  240   b  for stopping the roller support members  400   b  and the guide grooves  240   b  for guiding thee elastic members  500   b  are integrally formed with one housing plate  200   b , the number of parts of the hinged door fixing apparatus  100   b  is minimized, so more convenient assembly can be expected. 
     Hereinafter, the cover plate  600   b  and the fixing plate  700   b  are described in detail with reference to  FIGS. 18 and 19 . 
       FIG. 18  is a view showing in detail a cover plate for covering the housing plate of the hinged door fixing apparatus shown in  FIG. 15  and  FIG. 19  is a view showing in detail a fixing plate coupled to the cover plate of the hinged door fixing apparatus shown in  FIG. 15 . 
     Referring to  FIGS. 18 and 19 , the cover plate  600   b  is combined with the housing plate  200   b  to cover the receiving groove  230   b . In detail, the cover plate  600   b  may be combined with the housing plate  200   b  by fasteners (not shown) such as bolts or rivets or by hooks in a direct way. According to this configuration, it is possible to prevent the parts in the receiving groove  230   b  of the housing plate  200   b  from separating from the receiving groove  230   b . The cover plate  600   b  has a communicating hole  610   b , which communicates with the inlet  212 , at the center to pass the buffer ball  40   b  that is inserted and pulled out. 
     The fixing plate  700   b  is combined with the cover plate  600   b  in hook-type and fixed to the wall  30   b . In detail, hooks  710   b  facing opposite directions at corresponding positions may be formed on the fixing plate  700   b  and hook grooves  620   b  in which the hooks  710   b  are inserted are formed at positions corresponding to the hooks  710  in the cover plate  600   b . Further, the fixing plate  700   b  may have fixing holes  720   b  to be stably fixed to the wall  30   b  by fasteners (not shown) such as anchor pieces. Accordingly, a user can stably and simply mount the hinged door fixing apparatus  100   b  of the present invention on the wall  30   b  by fixing the fixing plate  700   b  first to the wall  30   b  in the way described above, and then simply fasten the cover plate  600   b  combined with the housing plate  200   b  to the fixing plate  700   b  using the hooks. A first communicating hole  730   b  that communicates with the communicating hole  610   b  to check the position where the buffer ball  40   b  hits against the wall  30   b  may be formed through the fixing plate  700   b.    
     Although the present invention was described above through exemplary embodiments, it would be understood by those skilled in the art or ordinary people in the art that the present invention may be changed and modified in various ways without departing from the spirit and scope of the present invention described in the following claims. 
     INDUSTRIAL APPLICABILITY 
     As described above, in order to prevent the doorknob or the edge of a hinged door from directly hitting against a wall when the hinged door opens, the buffer ball at the end of a buffer mounted on the hinged door is instantaneously and elastically held by the holder on the base fixed to the wall, thereby preventing the hinged door from slamming shut due to wind from the outside. Therefore, the present invention can be used to ensure safety of hinged doors that are generally used.