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STATEMENT REGARDING PRIOR DISCLOSURES 
     The present application claims the grace period exception under AIA 35 USC §102(b)(1)(A) to Korean Patent Registration No. 10-1559077 (published on Oct. 8, 2015), which is hereby incorporated by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a ball check valve apparatus, and more particularly to a ball check valve apparatus that is installed in a wastewater pipe to prevent wastewater from flowing backwards. 
     2. Description of the Related Art 
     In general, a check valve apparatus installed in a wastewater pipe according to the related art includes a structure that has a flip type opening/closing member mainly having a thin disk such that the interior of a pipe is selectively opened and closed while the opening/closing member is rotated forward or rearward. 
     However, as the opening/closing member of the check valve apparatus according to the related art is frequently opened and closed, fatigues are accumulated in the opening/closing member and thus, a hinge of the opening/closing member is frequently damaged. 
     Furthermore, a damage and impact noise are generated due to an excessive water impact when the opening/closing member closes the pipe, and solids contained in wastewater are interposed between the opening/closing member and the inner side of the pipe, making the operation of the opening/closing member unsmooth. 
     Moreover, because the check valve apparatus according to the related art separately includes a valve seat structure for supporting the opening/closing member, the structure of the check valve apparatus is complex so that the check valve apparatus cannot be easily manufactured and maintained, causing an increase in the price of the product due to deterioration of productivity. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in an effort to solve the above-mentioned problems, and provides a ball check valve apparatus that is installed to a wastewater pipe to reduce noise and damages to the ball check valve apparatus with a simple structure. 
     In accordance with an aspect of the present disclosure, there is provided a ball check valve apparatus including: a first body into which wastewater is introduced; a second body coupled to the first body to be communicated with the first body and configured to discharge the wastewater introduced into the first body; and a valve member disposed in the first body to be elevated and configured to close an opening/closing hole formed in the first body by the self-weight thereof and open the opening/closing hole by a pressure of wastewater introduced through the opening/closing hole. 
     The valve member may include a spherical opening/closing part seated at a periphery of the opening/closing hole, a connection part vertically extending from an upper side of the opening/closing part, and a guide ring disposed to be perpendicular to the connection part and having a pair of through-holes through which wastewater passes. 
     The ball check valve apparatus may further include a weight balancing boss vertically extending from a lower end of the opening/closing part. 
     The weight balancing boss may have an inverse conic shape. 
     The diameter of the guide ring may be larger than the diameter of a discharge hole formed in the second body. 
     According to the present invention, a separate hinge structure can be excluded from the valve member, and because, a valve seat structure of the valve member is provided in the first body  20  itself, the overall structure thereof can become simple and the ball check valve can be easily manufactured and maintained. 
     Furthermore, according to the present invention, because the opening/closing part of the valve member has a spherical shape to improve durability, damage to the ball check valve apparatus due to a water impact cause by the flows of the wastewater when the valve member is opened and closed can be reduced and noise can be reduced. 
     Because a hinge structure is excluded from the valve member and the valve seat structure of the valve member is provided for the first body, the overall structure of the ball check valve apparatus can be simplified and can be easily manufactured and maintained. 
     In addition, according to the present invention, because the opening/closing part of the valve member has a spherical shape to improve durability, damage to the ball check valve apparatus due to a water impact can be reduced and noise can be reduced when the valve member is opened and closed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view illustrating a ball check valve apparatus according to an embodiment of the present invention; 
         FIG. 2  is a plan view illustrating a valve member of  FIG. 1 ; 
         FIGS. 3 and 4  are sectional views illustrating coupled states in which an opening/closing hole is opened and closed as the valve member of the ball check valve apparatus according to the embodiment of the present invention is lifted and lowered; and 
         FIG. 5  is a perspective view illustrating another example of the valve member of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the embodiment described in the following is merely exemplary to help understanding of the present invention and may be variously modified differently from the embodiment of the present invention described herein. Meanwhile, in a description of the present invention, a detailed description and a detailed illustration of the known functions and configurations may be omitted to avoid making the essence of the present invention obscure. Further, the elements are not illustrated in actual scales but some of the elements may be exaggerated to help understanding of the present invention. 
     Referring to  FIGS. 1 to 3 , a ball check valve apparatus  10  according to an embodiment of the present invention includes a first body  20 , a second body  30 , and a valve member  40 . 
     The first and second bodies  20  and  30  are disposed between first and second wastewater pipes  51  and  53  (see  FIG. 3 ) for feeding wastewater discharged from a wastewater collection tank (not illustrated). 
     A lower part  35  of the second body  30  is separately inserted into an upper part  21  of the first body  20 . In this case, an accommodation space  21   a  that defines a movement space in which a valve member  40  may be elevated is formed inside the upper part  21  of the first body  20 . The accommodation space  21   a  also acts as a passage through which wastewater passes. 
     The upper part  21  of the first body  20  is inclined such that a lower end  21   b  of the first body  20  becomes gradually narrower as towards the center of the first body  20 . Accordingly, an opening/closing hole  22  opened and closed by the valve member  40  is formed inside the first body  20 . A periphery of the opening/closing hole  22  acts as a valve seat in which a valve member  40  may be seated. 
     A screw part  26  is formed at an outer periphery of the lower part  23  of the first body  20  to be screw-coupled to a first wastewater pipe  51 . In this case, a hexagonal protrusion  25 , with which the head of a spanner (not illustrated) may be fitted, is formed such that the first body  20  may be easily screw-coupled to a first wastewater pipe  51  (here, the first wastewater pipe  51  is directly communicated with a pump (not illustrated)). 
     Moreover, although it is illustrated in the embodiment of the present invention that the screw part  26  of the first body  20  is connected to the first wastewater pipe  51 , the present invention is not limited thereto but the screw part  26  may be directly coupled to the pump (not illustrated). In this case, because a common pump generally has a female thread at an inner periphery of a coupling hole (not illustrated), to which a pipe is connected, it is preferable that the screw part  26  has a male thread in this aspect. 
     As described above, the lower part  35  of the second body  30  is inserted into the upper part  21  of the first body  20 . The second body  30  has a coupling hole  33 , to which one end of a second wastewater pipe  53  is inserted, inside an upper part  31  of the second body  30 . 
     A discharge hole  34  communicated with the accommodation space  21   a  of the first body  20  is formed inside the second body  30 . In this case, it is preferable that the diameter of the discharge hole  34  is smaller than the diameter of a guide ring  45  of the valve member  40 . This structure prevents the valve member  40  from deviating from the accommodation space  21   a  of the first body  20  when the valve member  40  is moved upwards by a hydraulic pressure of the wastewater. 
     The valve member  40  includes an opening/closing part  41 , a connection part  43 , a guide ring  45 , and a weight balancing boss  48 . 
     The opening/closing part  41  closes the opening/closing hole  22  of the first body  20  by the self-weight thereof (see  FIG. 3 ), and in contrast, opens the opening/closing hole  22  while rising due to the pressure of the wastewater introduced through an interior space  23   a  of the lower part  23  of the first body  20  (see  FIG. 4 ) 
     The connection part  43  is formed to be substantially perpendicular to the upper side of the opening/closing part  41 , and supports the guide ring  45  and spaces the guide ring  45  to the upper side of the opening/closing part  41  such that the guide ring  45  maintains a predetermined interval with the opening/closing part  41 . 
     In this case, it is preferable that the connection part  43  has a substantially plate shape and has a thin plate shape not to be interfered by the flows of the wastewater that passes through the accommodation space  21   a  of the first body  20  through the opening/closing hole  22 . 
     The guide ring  45  is disposed substantially horizontally, and a pair of through-holes  46   a  and  46   b  are formed by the connection part  43  as illustrated in  FIG. 2 . Various solids contained in the wastewater as well as the waste water pass through the pair of through-holes  46   a  and  46   b    
     As illustrated in  FIG. 4 , the spherical opening/closing part  41  that is lifted by a pressure as the wastewater is introduced through the opening/closing hole  22  is not rotated but lifted substantially vertically by the guide ring  45 . 
     The weight balancing boss  48  extends vertically downwards from a lower end of the opening/closing part  41 . In this case, the weight balancing boss  48  is disposed in the vertical direction as that of the connection part  43 . 
     Because the weight balancing boss  48  acts as a weight pendulum, the center of weight of the opening/closing part  41  may be situated on the lower side of the center of the opening/closing part  41  when the opening/closing part  41  is elevated such that the posture of the opening/closing part  41  is maintained together with the aforementioned guide ring  45 . 
     Referring to  FIG. 5 , the opening/closing member  40   a  may has a weight balancing boss  48   a  having a different shape from the aforementioned weight balancing boss  48  of the opening/closing member  40 . 
     The weight balancing boss  48   a  may have a substantially inverse conic shape at a lower end of the opening/closing part  41 . 
     In this way, when the weight balancing boss  48   a  is manufactured to have an inverse conic shape, the wastewater introduced into the opening/closing hole  22  may be guided upwards while the interference with the outside of the opening/closing part  41  along an outer peripheral surface of the weight balancing boss  48   a  is minimized. Accordingly, the flows of the wastewater that passes through the accommodation space  21   a  of the first body  20  may become smoother. 
     As described above, because a hinge structure is excluded from the valve member  40  and the valve seat structure of the valve member  40  is provided for the first body, the overall structure of the ball check valve apparatus can be simplified and can be easily manufactured and maintained. 
     In addition, according to the present invention, because the opening/closing part  41  of the valve member  40  has a spherical shape to improve durability, damage to the ball check valve apparatus due to a water impact can be reduced and noise can be reduced when the valve member  40  is opened and closed. 
     Although the present invention has been with reference to the limited embodiment and the drawings, the present invention is not limited thereto, but it should be noted that the present invention can be variously corrected and modified by those skilled in the part to which the present invention pertains within the technical spirit of the present invention and the equivalents of the claims, which will be described below.

Summary:
Provided is a ball check valve apparatus including: a first body into which wastewater is introduced; a second body coupled to the first body to be communicated with the first body and configured to discharge the wastewater introduced into the first body; and a valve member disposed in the first body such that the valve member is movable up and down in the first body and configured to close an opening/closing hole formed in the first body by a self-weight thereof and open the opening/closing hole by a pressure of wastewater introduced through the opening/closing hole.