Patent Publication Number: US-2005139689-A1

Title: Refrigerator having pressure equilibrium apparatus

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a refrigerator, and more particularly to a refrigerator having a pressure equilibrium apparatus for equilibrating pressures between the inside and outside of the refrigerator to allow easy opening of a door from the refrigerator.  
      2. Description of the Related Art  
      Generally, a refrigerator comprises a main body having a refrigerating space, a door, for opening and closing the main body, installed on a front surface of the main body, and internal machinery for constituting a refrigerating cycle supplying cool air to the refrigerating space. The internal machinery includes a compressor, a condenser, a capillary tube, and an evaporator.  
      When the temperature of the refrigerating space is lowered by the internal machinery constituting the refrigerating cycle, the pressure of the refrigerating space is lower than the pressure of the external atmosphere.  
      In case that there is generated a difference of pressures between the refrigerating space and the external atmosphere, the difference of pressures causes a difficulty of opening the door from the main body of the refrigerator, thereby causing inconvenience to users of the refrigerator.  
     SUMMARY OF THE INVENTION  
      Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a refrigerator having a pressure equilibrium apparatus with a simple structure for equilibrating pressures between the inside and outside of the refrigerator to allow easy opening of a door from the refrigerator.  
      It is another object of the present invention to provide a refrigerator having a pressure equilibrium apparatus, in which a case is firmly sealed and the weight of a weight body is easily adjusted.  
      It is yet another object of the present invention to provide a refrigerator having a pressure equilibrium apparatus, which prevents external foreign substances from being introduced into a main body of the refrigerator when the pressures of the inside and outside of the main body are equilibrated.  
      In accordance with the present invention, the above and other objects can be accomplished by the provision of a refrigerator having a pressure equilibrium apparatus, comprising: a through hole formed through a main body for communicating a refrigerating space of the main body with the outside therethrough; a case inserted into the through hole and provided with opened upper and lower surfaces; and a switching unit, installed in the case and rotated by its own weight to open and close the case, for achieving pressure equilibrium between the refrigerating space and the outside of the main body.  
      Preferably, in order to efficiently open and close the case, the switching unit may include a hinge body hinged to the case such that both ends of the hinge body contact the inner surface of the case; a sealing protrusion horizontally extended from one side of the hinge body so that one portion of the inside of the case is sealed by the sealing protrusion; and a weight body horizontally extended from the other side of the hinge body so that the other portion of the inside of the case is sealed by the weight body.  
      Preferably, in order to efficiently seal the case by means of the switching unit, an upper protrusion may be formed on the inner surface of the case so as to contact the upper surface of the sealing protrusion, and a lower protrusion may be formed on the inner surface of the case so as contact the lower surface of the weight body.  
      Preferably, in order to easily adjust the weight of the weight body, a cavity may be formed in the upper surface of the weight body, and a counterweight made of metal may be inserted into the cavity.  
      Preferably, in order to prevent foreign substances from being introduced into the main body, a cover may be attached to the outer surface of the main body corresponding to the through hole, and a filter net may be installed on the cover.  
      Preferably, a flange may be formed on the circumference of the upper end of the case so that the case is caught by the outer surface of the main body around the periphery of the through hole.  
      Preferably, in order to rapidly rotate the switching unit, the transverse length of the sealing protrusion may be longer than that of the weight body.  
      Preferably, in order to efficiently discharge condensed water generated from the case and the switching unit, the through hole may be placed above a bucket of an evaporator installed in the main body. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the-accompanying drawings, in which:  
       FIG. 1  is a perspective view of a pressure equilibrium apparatus in accordance with the present invention;  
       FIG. 2  is a longitudinal-sectional view of the pressure equilibrium apparatus in  FIG. 1 ;  
       FIG. 3  is a schematic longitudinal-sectional view of a refrigerator comprising the pressure equilibrium apparatus installed therein in accordance with one embodiment of the present invention;  
       FIG. 4  is, an enlarged view of a main portion of  FIG. 3 ;  
       FIG. 5  is a schematic view illustrating the operation of the pressure equilibrium apparatus in  FIG. 4 ; and  
       FIG. 6  is an enlarged longitudinal-sectional view of a refrigerator comprising a pressure equilibrium apparatus installed therein in accordance with another embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Now, preferred embodiments of the present invention will be described in detail with reference to the annexed drawings.  
       FIG. 1  is a perspective view of a pressure equilibrium apparatus in accordance with the present invention, and  FIG. 2  is a longitudinal-sectional view of the pressure equilibrium apparatus in  FIG. 1 .  
      As shown in  FIGS. 1 and 2 , the pressure equilibrium apparatus comprises a case  20  provided with opened upper and lower surfaces, and a switching unit  30  placed in the case  20 .  
      The case  20  includes an upper protrusion  21  formed on the inner surface thereof, a lower protrusion  22  formed on the inner surface thereof, and a flange  23  formed on the circumference of the upper end thereof.  
      The switching unit  30  includes a hinge body  31  hinged to the inner surface of the case  20 , a sealing protrusion  32  formed on one side of the hinge body  31 , and a weight body  33  formed on the other side of the hinge body  31 . A counterweight  35  made of metal is inserted into a cavity  34  formed in the upper surface of the weight body  33 .  
      The case  20  is firmly attached to a main body of a refrigerator, and serves as a passage communicating with air and a supporter for supporting the switching unit  30 .  
      The switching unit  30  serves to seal the inside of the case  20  by causing the upper surface of the sealing protrusion  32  to contact the upper protrusion  21  and the lower surface of the weight body  33  to contact the lower protrusion  22 , and, when there is generated a difference of pressures between the inside and outside of the refrigerator, to rotate to open the inside of the case  20  by allowing the sealing protrusion  32  to descend centering on the hinge body  31  and the weight body  33  to ascend centering on the hinge body  31 .  
      The inside of the case  20  is opened by the rotation of the sealing protrusion  32  and the weight body  33  in a regular direction, thereby achieving pressure equilibrium between the inside and outside of the refrigerator. Thereafter, the sealing protrusion  32  and the weight body  33  are rotated in the opposite direction by the weight of the weight body  33 , thereby being returned to their initial positions.  
      That is, the switching unit  30  is rotated to eliminate the difference of pressures between the inside and outside of the refrigerator, and is then returned to its initial state by the weight of the weight body  33 , thereby maintaining the pressure equilibrium of the refrigerator without using any separate driving means.  
      Since the weight poise  35 , made of a metal and inserted into the cavity  34  formed in the upper surface of the weight body  33 , is easily replaced with another one, it is possible to easily adjust the total weight of the weight body  33 .  
      When the inside of the case  20  is opened by rotating the sealing protrusion  32  and the weight body  33 , external air is rapidly introduced into the case  20  through gaps between the sealing protrusion  32  and the upper protrusion  21  and between the weight body  33  and the lower protrusion  22 , thereby allowing the pressures of the inside and outside of the refrigerator to be equilibrated.  
      When the case  20  is inserted into a through hole formed through the main body of the refrigerator, the flange  23 , formed on the circumference of the upper end of the case  20 , is caught by the external surface of the main body around the through hole, thereby easily fixing the case  20  to the main body.  
      The transverse length of the sealing protrusion  32  is longer than that of the weight body  33 . This structure expands the dimensions of the sealing protrusion  32 , and increases the resistance of external air generated on the upper surface of the sealing protrusion  32  due to the difference of pressures between the inside and outside of the refrigerator, thereby facilitating the rotation of the switching unit  30 .  
       FIG. 3  is a schematic longitudinal-sectional view of a refrigerator comprising the pressure equilibrium apparatus installed therein in accordance with one embodiment of the present invention.  FIG. 4  is an enlarged view of a main portion of  FIG. 3 .  FIG. 5  is a schematic view illustrating the operation of the pressure equilibrium apparatus in  FIG. 4 .  
      As shown in  FIGS. 3 and 4 , the refrigerator comprises a main body  10  having a refrigerating space  12  therein, a door  13 , for opening and closing the main body  10 , installed on a front surface of the main body  10 , and a compressor  14 , a condenser  15 , a capillary tube  16  and an evaporator  17  constituting a refrigerating cycle for supplying cool air to the refrigerating space  12 .  
      A through hole  11  is formed through the upper surface of the main body  10 , and the pressure equilibrium apparatus comprising the case  20  and the switching unit  30  is installed in the through hole  11 .  
      The through hole  11  serves as a space, through which the refrigerating space  12  of the main body  10  of the refrigerator communicates with the outside of the refrigerator, and in which the pressure equilibrium apparatus is installed.  
      The case  20  is fixed to the main body  10  by the contact between the flange  23  of the case  20  and the outer surface of the main body  10  around the circumference of the upper end of the through hole  11 , and the switching unit  30  including the hinge body  31 , the sealing protrusion  32  and the weight body  33  is installed in the case  20 .  
      Since the through hole  11  is placed above a bucket  18  of the evaporator  17  installed in the main body  10 , condensed water, generated from the case  20  and the switching unit  30  due to the difference of temperatures between the inside and outside of the refrigerator, drops into the bucket  18 .  
      As shown in  FIG. 4 , when there is not generated a difference of pressures between the inside and outside of the refrigerator, the upper surface of the sealing protrusion  32  contacts the lower surface of the upper protrusion  21  and the lower surface of the weight body  33  contacts the upper surface of the lower protrusion  22 , thereby sealing the inside of the case  20 .  
      As shown in  FIG. 5 , when there is generated a difference of pressures between the inside and outside of the refrigerator, i.e., when the pressure of the refrigerating space  12  of the refrigerator is lower than the pressure of the outside, in order to achieve pressure equilibrium between the inside and outside of the refrigerator, the sealing protrusion  32  is pushed downwardly by the external air and rotated centering on the hinge body  31 , and the weight body  33  ascends.  
      Here, the external air is rapidly introduced into the inside of the refrigerator through gaps between the sealing protrusion  32  and the upper protrusion  21  and between the weight body  33  and the lower protrusion  22 , thereby allowing the pressures of the inside and outside of the refrigerator to be equilibrated.  
      After the pressures of the inside and outside of the refrigerator are equilibrated by opening the case  20  by the rotation of the sealing protrusion  32  and the weight body  33  in a regular direction centering on the hinge body  31 , the sealing protrusion  32  and the weight body  33  are rotated in the opposite direction centering on the hinge body  31  by the weight of the weight body  33  so that the weight body  33  descends and the sealing protrusion  32  ascends, thereby being returned to their initial positions as shown in  FIG. 4 . Thus, the case  20  is sealed by the switching unit  30 .  
       FIG. 6  is an enlarged longitudinal-sectional view of a refrigerator comprising a pressure equilibrium apparatus installed therein in accordance with another embodiment of the present invention.  
      As shown in  FIG. 6 , the through hole  11  is formed through the upper surface of the main body  10 , and the pressure equilibrium apparatus comprising the case  20  and the switching unit  30  is installed in the through hole  11 .  
      A cover  40  is attached to the outer surface of the main body  10  corresponding to the through hole  11 , and a filter net  41  is installed on the cover  40 .  
      The cover  40  and the filter net  41  installed thereon, when the case  20  is opened by the rotation of the sealing protrusion  32  due to the difference of pressures between the inside and outside of the refrigerator and the external air is introduced into the inside of the main body the refrigerator, serve to filter out foreign substances introduced into the main body  10  together with the external air.  
      That is, the filter net  41  serves to prevent foreign substances from being introduced into the main body  10  during the pressure equilibrium between the inside and outside of the refrigerator.  
      As apparent from the above description, the present invention provides a refrigerator having a pressure equilibrium apparatus, rotated by its own weight, for achieving pressure equilibrium between the inside and outside of the refrigerator, thereby facilitating the opening and closing of a door of the refrigerator and providing convenience to users.  
      Although the preferred embodiments of the present invention have been disclosed 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.