Patent Publication Number: US-2022235995-A1

Title: Refrigeration appliance with an evaporator mounted on an inner wall and method for the assembly thereof

Description:
The present invention relates to a refrigeration appliance, in particular a household refrigeration appliance, having an inner space and an evaporator that is mounted on a wall of the inner space, and also to a method for mounting said evaporator. 
     During the assembly procedure of such a refrigeration appliance, it is necessary to first attach the evaporator to the intended installation site in the inner space in a reliable manner so that the refrigerant circuit may be subsequently connected. 
     A refrigeration appliance is known from U.S. Pat. No. 8,047,017 B2 in which a fin evaporator is mounted on a rear wall of the inner space with the aid of a retaining device that comprises a base plate, which lies against the rear wall, and elastic protrusions that protrude from the base plate. Bent outward from individual fins of the evaporator are perforated brackets that are pushed during the assembly procedure of the evaporator against the protrusions in order to latch the protrusions into the holes. When the evaporator is in the mounted state, it conceals the protrusions with the result that it is difficult to bring the protrusions into alignment with the holes in the brackets. 
     Elongated protrusions are formed on two edges of the base plate, which limit the freedom of movement of the brackets with respect to the protrusions by engaging around the outer fins of the evaporator. Although this may facilitate the insertion of the protrusions into the holes, it does at the same time create a path along which air may flow past on the outer faces of the evaporator. 
     The object of the invention is to provide a refrigeration appliance in which it is possible to mount the evaporator in a rapid and reliable manner, and to provide a corresponding method for mounting said evaporator. 
     The object is achieved on the one hand in that in the case of a refrigeration appliance that comprises an inner space, an evaporator assembly, which extends on a wall of the inner space, and a retaining device, which comprises a base plate that extends between the wall and the evaporator assembly, and protrusions that protrude on a first and a second edge of the base plate from the wall, at least the protrusion that protrudes on the first edge comprises an elastic clip that may be deflected from a position in which said elastic clip engages around a first outer section of the evaporator assembly into a position in which said elastic clip releases the outer section. Although the clip is elastically deformed in a similar manner to the protrusions disclosed in U.S. Pat. No. 8,047,017 B2 so that the evaporator assembly may achieve its installation position, it is however the case that since said clip engages around the outside of the evaporator assembly, said clip remains visible during the attachment procedure, in addition a temporarily intense deflection of the clip may not prevent it achieving the position in which in engages around said evaporator assembly, whereas in the case of conventional protrusions an excessive bending may prevent the protrusion latching into the hole that is provided for said protrusion. 
     The protrusion that protrudes on the second edge may comprise a recess that is facing the first protrusion. A second outer section of the evaporator assembly may be plugged into this recess. By virtue of plugging in a second outer section in this manner, it is possible to determine a pivot axis around which the evaporator assembly may pivot with respect to the base plate, wherein the spacing between the first and the second protrusion should be matched to the length of the evaporator assembly in such a manner that during this pivot movement the clip impinges directly on the first outer section that said clip is to engage around on completion of the pivot movement. The recess may be formed in a wall plate of the retaining device, on the edges of which connecting pieces are bent outward in the direction of the first protrusion; however other forms of recess are also conceivable such as a hole in a wall plate of the retaining device into which a protrusion of the evaporator assembly engages. 
     The evaporator assembly may comprise in addition to one evaporator at least one, preferably two, bypass blockers, in other words shaped parts that are attached to the flanks of the evaporator and whose shape is tailored to suit the installation space available for the evaporator assembly in order to fill up intermediate spaces between the evaporator and the walls of the installation space and thus to prevent air flowing past the evaporator. 
     Since it is possible to adapt the shape of such a bypass blocker more easily than to adapt the shape of the evaporator in order to facilitate the spring engaging around said evaporator, at least the first outer section of the evaporator assembly should be formed by a bypass blocker. 
     It is preferred that the evaporator is a fin evaporator having laterally protruding tube loops. The bypass blocker may comprise recesses on a flank facing the evaporator, wherein the tube loops engage into said recesses in a frictional or form-locking manner in order to hold the evaporator assembly together. 
     The bypass blocker is embodied preferably from an easily deformable material, in particular a foamed material such as expanded polystyrene. This ability to deform facilitates on the one hand the procedure of densely filling the installation space despite manufacturing tolerances, in that the bypass blocker is deformed into contact with the walls of the installation space; on the other hand said ability to deform facilitates the production of an effective frictional connection with the tube loops of the evaporator. 
     In order that the bypass blocker may on the one hand fill up an installation space, which is provided for said bypass blocker, and may prevent air flowing around the evaporator and at the same time space remains for the clip to deflect, the bypass blocker may comprise on an edge that is remote from the evaporator a groove in which the elastic clip extends at least in its position in which said elastic clip engages around the edge. 
     It is possible to form an insertion slope on an end of the groove that is facing the base, in other words the depth of the groove may increase towards the base plate, with the result that the clip initially, without having to be deformed or by deforming slightly, may latch into the groove and, if subsequently the evaporator assembly is pushed against the base plate, is deflected in a gradually increasing manner into contact with the base of the groove. The width of the groove may also increase toward the base plate in order to also then render it possible for the clip to latch into the groove if the evaporator assembly is not positioned precisely in the width direction of the groove, and to gradually correct the position of the evaporator group in this direction by means of latching the clip into the groove. 
     In order to fix the evaporator assembly in a reliable manner, the first protrusion may moreover comprise at least one rigid wall plate that lies against a flank of the bypass block that is remote from the evaporator. Any wall plate may be considered as rigid in this sense. 
     In the interest of a cost-efficient manufacturing process, the entire retaining device is preferably formed as one piece from a flat material in particular a metal sheet. 
     In order not to hinder the deflection movement of the clip, the rigid wall is preferably separated from the elastic clip by means of a section that extends as far as the base plate. 
     In order to prevent the evaporate assembly sliding out of position in the direction of the first edge of the base plate, the protrusion may comprise at least one connecting piece that is oriented in a transverse manner with respect to the first edge. 
     In order to keep the structure of the retaining device simple, this connecting piece is preferably bent outward at an angle from an edge of the rigid wall plate. 
     Two such connecting pieces may fix the evaporator assembly in a form-locking manner, in that they lie respectively against a flank of the evaporator assembly, said flank being upstream or downstream with regard to the flow direction of air through the evaporator. 
     In order to attach the base plate to the wall, it is desirable to perform the attachment without penetrating the wall since such penetrations could lead to leakages and to insulating material penetrating the inner space or to water from the inner space passing into the insulation material. The base plate is therefore preferably attached by means of adhesive to the wall; in particular with the aid of an adhesive strip, that bridges a third edge of the base plate in order to adhere in part to the base plate and in part to the wall. 
     A condensed water channel may be formed on a fourth edge of the base plate in order to collect and discharge condensed water that is flowing out during the operation of the evaporator. 
     The condensed water channel may support the anchoring of the retaining device in the inner space, in that said holding device engages in a channel that is formed in the wall. 
     In order to drain off water that has collected in the condensed water channel, a drain should be formed on the wall. This drain may also be used to anchor the retaining device, in that a plug connector penetrates a drain opening of the condensed water channel and engages in the drain. 
     In order to facilitate the assembly procedure of the refrigeration appliance, an evaporator heater may be a component of the evaporator assembly with the result that said evaporator heater is inserted into the inner space together with the evaporator. 
     The object is achieved on the one hand by means of a method for mounting an evaporator assembly on a wall of an inner space of a refrigeration appliance, said method comprising the steps:
         a) attaching a retaining device to the wall; wherein the retaining device comprises a base plate and protrusions that protrude on a first and a second edge of the base plate from the wall;   b) placing the evaporator assembly on the second protrusion that protrudes from the second edge; and   c) pivoting the evaporator assembly about an axis, which is adjacent to the second protrusion, in the direction of the base plate until said evaporator assembly is in a position in which an elastic clip of the protrusion that protrudes on the first edge engages around a first outer section of the evaporator assembly.       

     In order that the evaporator assembly may be placed on the second protrusion in a reliable manner and pivoted, the steps b) and c) should be performed with the refrigeration appliance in a horizontal orientation, in which in step b) the second protrusion supports the evaporator assembly. 
     The axis for the pivot movement of step c) may then be defined in a simplest manner conceivable by means of a spot where the second protrusion and the evaporator assembly make contact, typically therefore a spot on a wall plate of the second protrusion on which the evaporator assembly rests, said wall plate being horizontal when the refrigeration appliance is lying in a horizontal orientation. 
    
    
     
       Further features and advantages of the invention are disclosed in the description of exemplary embodiments with reference to the attached figures, in which: 
         FIG. 1  shows a retaining device for mounting an evaporator assembly in the inner space of a refrigeration appliance; 
         FIG. 2  shows the retaining device having an evaporator assembly inserted therein; 
         FIG. 3  shows a section through a bypass blocker of the evaporator assembly; 
         FIG. 4  shows a schematic section through a housing of a refrigeration appliance in accordance with the invention prior to the installation of the evaporator assembly; 
         FIG. 5  shows a section through the wall of the refrigeration appliance and a retaining device mounted thereon for the evaporator assembly; 
         FIG. 6  shows a section similar to  FIG. 4  during the installation of the evaporator assembly; 
         FIG. 7  shows a further section similar to  FIG. 4  during the installation of the evaporator assembly; and 
         FIG. 8  shows a section similar to  FIG. 4  after the installation of the evaporator assembly. 
     
    
    
       FIG. 1  illustrates a perspective view of a retaining device  1  that is provided for mounting an evaporator assembly in the inner space of a refrigeration appliance, in particular of a household refrigeration appliance such as a refrigerator or a freezer. The retaining device  1  is formed as one piece from a section of sheet metal. Said retaining device has a rectangular base plate  2  that is provided so as in the mounted state to lie against a wall, in particular a rear wall, of the inner space. The section is bent over on two edges  3 ,  4  of the base plate  2  in order to form protrusions  5 ,  6 , said edges being oriented in a vertical manner when the refrigeration appliance is finished and set upright in the position of use. 
     The protrusion  5  comprises a wall plate  7  that extends over a major part of the edge  3  and protrudes at a right angle with respect to the base plate  2 . On an upper and lower edge and also on an edge that is remote from the base plate  2 , connecting pieces  8 ,  9 ,  10  are in turn bent outward away from the wall plate  7  in order to form a flat recess  11  that is facing the other protrusion  6 . In order to make the connection between the wall plate  7  and the base plate  2  as bend-resistant as possible, corrugations  12  are distributed along the edge  3 , said corrugations  12  extending in each case into the base plate  2  and the wall plate  7 . 
     The protrusion  6  is divided into three parts, two outer and one middle part, along the edge  4  by means of sections  13  that extend in each case as far as the base plate  2 . The two outer parts  14 ,  15  comprise respectively as the protrusion  5  a wall plate  16  or  17 , which protrudes at a right angle from the base plate  2 , and a connecting piece  18  or  19  that is bent outward on the outer edge of the wall plate  16 ,  17  toward the protrusion  5 . However, in contrast to the protrusion  5 , a connecting piece that is bent outward toward the opposite-lying protrusion is not provided on the edge  20  of the wall plates  16 ,  17 , said edge being remote from the base plate  2 . The connection between the wall plates  16 ,  17  is reinforced by means of corrugations  12  that extend across the edge  4 . 
     The middle part of the protrusion  5  is formed as a clip  21  having an arm  22  that protrudes from the base plate and that in order to be flexible is narrower than the plates  16 ,  17  and is connected to the base plate  2  via a section of the edge  4  that is not provided with corrugations and having a barbed hook  23  that protrudes outward from the free end of the arm  22  beyond the base plate  2 . In order to realize a uniform curvature of the arm  22  in the case of a sideward deflection of the barbed hook  23 , the width of the arm  22  continuously reduces from the edge  4  toward the barbed hook  23 . 
     A condensed water channel  24  is formed on a third edge of the base plate  2 , said third edge being the lower edge after the retaining device  1  has been installed in the finished refrigeration appliance. The condensed water channel  24  slopes toward the middle from its two ends on the edges  3 ,  4  and comprises a through-going passage  25  at its deepest point. The angle between the base plate  2  and the condensed water channel  24  is reinforced by means of further corrugations  12 . 
       FIG. 2  illustrates the retaining device  1  having an evaporator assembly  26  mounted therein. A middle section of the evaporator assembly  26  is formed by means of an evaporator  27 , in this case a fin evaporator. The evaporator  27  comprises in a manner known per se a plurality of mutually parallel fins  28  and a refrigerant tube  29  that extends in a meandering manner through openings of the fins  28 , wherein tube loops of the refrigerant tube  29  protrude beyond the outer fins  28 . End pieces  58  of the refrigerant tube  29  that are still unconnected and are to be inserted into a refrigerant circuit of the refrigeration appliance extend beyond the block of fins  28 . 
     An evaporator heater  59 , in this case in the form of a tube that is bent in the shape of a hair pin and contains an electrical heating resistor, extends below the evaporator  27 . The tube is pushed into openings in two fins  28  that protrude downward beyond the block-shaped evaporator  27 . The evaporator heater  59  is used in a manner known per se for defrosting white frost that during the operation precipitates on the evaporator  27  as a result of radiation and rising warm air. 
     Two bypass blockers  30 ,  31  that form the outer sections of the evaporator assembly  26  are attached to the outer fins  28  lying on both sides on the evaporator  27 . The protruding tube loops of the evaporator engage in recesses of the bypass blocker  30 ,  31  and therefore are not visible in  FIG. 2 . The bypass blockers  30 ,  31  are shaped bodies embodied from a closed-pore synthetic material foam, typically from expanded polystyrene. 
     The bypass blocker  30  engages in the recess  11  of the protrusion  5  and by being in contact with the mutually opposite connecting pieces  8 ,  10  or rather with the connecting piece  9  and the base plate  2  is held so as not to move in the direction of the edge  3  and also in the direction that is perpendicular to the base plate  2 . A part of the bypass blocker  30  extends upward beyond the connecting piece  8  and forms a rib  32  that protrudes outward in the lateral direction beyond the wall plate  7 . A further rib  60  protrudes forward between the connecting piece  9  and the evaporator  27  in the direction of the observer. 
     The bypass blocker  31  has on its outer face that is remote from the evaporator  27  a groove  33  that receives the clip  21 . The groove  33  is flanked on the upper and lower side by ribs  34  that protrude to the side outward through the cut-outs  13  beyond the wall plates  16 ,  17 . The front edges  20  of the wall plates  16 ,  17  are bent behind ribs  61  of the bypass blocker  31 , said ribs protruding forward beyond the wall plates  16 ,  17 . 
       FIG. 3  illustrates a cross-section through the bypass blocker  31  along a plane that extends through the groove  33  and perpendicular to its flank  35  that is facing the evaporator  27 . The groove  33  extends along a flank  36 , which is remote from the evaporator  27 , from a rear side  37 , which lies against the base plate  2 , as far as a front side  38  of the bypass blocker  31 , said front side being remote from the base plate  2 . The depth of the groove  33  gradually reduces along an insertion slope  39 , which is open toward the rear side  37 , starting from the rear side  37  to a minimum  40 . The minimum  40  extends in this case in a longitudinal manner along the flank  35  and extends as far as just before the front side  38 . 
     The arm  22  of the clip  21  is just sufficiently long that when the evaporator assembly  26  is pushed against the base plate  2 , the barbed hook  23  may pass the minimum  40  and as illustrated in  FIG. 3  may engage in a deeper section of the groove  33  between the minimum  40  and the front side  38  with the result that the clip  21  engages around an edge of the evaporator assembly  26 . 
     Recesses  41  somewhat in the shape of semi-circular discs are formed on a flank  36  of the bypass blocker  31 , said flank lying opposite the flank  35  and facing the evaporator  27 , said recesses being provided in order to receive the above mentioned tube loops of the refrigerant tube  29 . Corresponding recesses are also provided on the bypass blocker  30 . The width of the recesses  41  is somewhat less that the diameter of the refrigerant tube  29  in order to ensure by means of a frictional or form-locking connection that the bypass blocker  30 ,  31  sits firmly on the evaporator  27 , that the evaporator  27  and the bypass blocker  30 ,  31  may be joined together to form the evaporator assembly  26  prior to being installed in the inner space of the refrigeration appliance and reliably holds together this evaporator assembly  26  as it is being installed. 
       FIG. 4  illustrates a schematic section through the rearward part of a housing  42  of a still unfinished refrigeration appliance along a plane that extends horizontally when the appliance is set upright in the position of use. The figure illustrates a part of an inner space  43  and part of side walls  44  and also a rear wall  45  of the housing  42 . The retaining device  1  is mounted in the inner space  43  with the base plate  2  lying against the rear wall  45 . The width of the retaining device  1  is smaller than that of the inner space  43  with the result that gaps  46  remain between the protrusions  5 ,  6  and the side walls  44  respectively. The width of the gap  46  varies depending upon the width of the housing  42 . 
       FIG. 5  illustrates a section through the refrigeration appliance along a plane that is perpendicular to the section plane of  FIG. 4  and vertical when the finished refrigeration appliance is in the position of use. The plane is described in  FIG. 4  by V-V and extends through the through-going passage  25  of the condensed water channel  24  and an upper edge  47  of the base plate  2 . The rear wall  45  comprises a layer of insulating material  48  and an inner vessel  49  that separates the layer of insulating material  48  from the inner space  43 . A groove  50  is formed on a lower edge of the rear wall  45  in the inner vessel  49  and the condensed water channel  24  of the retaining device  1  is inlaid in said inner vessel. 
     The retaining device  1  is fixed in the illustrated position with the aid of an adhesive band  51 , typically an aluminum adhesive band, which bridges the upper edge  47  of the base plate  2 , adhered in part to the base plate  2  and in part to the inner vessel  49  and also with the aid of a plug connector  52 . The plug connector  52  has a pin section  53  that penetrates the opening  25  and engages in a drain  54  that is formed on the inner vessel  49  and extends through the layer of insulating material  48  into the atmosphere, and a head  55 , the diameter of which is greater than the diameter of the through-going passage  25 . The condensed water channel  24  is also fixed in the groove  50  by virtue of the pin section  53  being held in the drain  54 , for example by means of a frictional connection or a latching arrangement. 
     In order not to block the outflow of the condensed water, the plug connector  52  may not fill the cross-section of the drain  54 . The pin section  53  therefore has in this case a U-shaped cross-section having a groove  56  that extends over the entire length of the pin section  53  and on its upper end becomes one or multiple grooves  57  on the lower face of the head  55 . 
     In order to install the evaporator assembly  26  in the refrigeration appliance illustrated in  FIGS. 4 and 5 , the housing  42  is placed on the side with the result that the protrusion  5  of the retaining device  1  comes to lie at the very bottom. Subsequently, as illustrated in  FIG. 6 , the evaporator assembly  26  is inserted into the inner space  43  in an inclined position and its bypass blocker  30  is placed in the recess  11  of the protrusion  5 . 
     Subsequently the evaporator assembly  26  is pivoted against the rear wall  45  about the axis that is determined by means of the bypass blocker  30  engaging in the recess  11 . As a consequence, the barbed hook  23  of the clip  21  comes to lie against the entrance of the groove  33  of the bypass blocker  31 . 
     During a further pivot movement, the barbed hook  23  engages into the groove  33  and by virtue of making contact with its base in the region of the insertion slope  39  is deflected upward, in other words toward the side wall  44  of the housing  42 , said side wall being the upper side wall in the horizontal position ( FIG. 7 ), until said barbed hook finally passes the minimum  40  and engages between this and the front side  38  further deeper into the groove  33  and thus engages around the bypass blocker  31  as illustrated in  FIG. 8 . 
     As the same time as the clip  21  moves into the groove  33 , the ribs  34  (not illustrated in  FIGS. 6-8 ) also engage in the sections  13 . It is thus possible to dimension their lateral overhang in such a manner that after the clip  21  has latched in the groove  33  said ribs fill the gap  46  between the wall plates  16 ,  17  and the upper side wall  44 . 
     Accordingly, the rib  32  of the bypass blocker  30  is dimensioned in order to bridge the gap  46  between the wall plate  7  and the lower side wall  44 . If the bypass blockers  30 ,  31  are provided in different shapes having respectively a height of the ribs  32 ,  34  that is tailored to suite the width of the housing  42 , it is possible to use an identical model of evaporator  27  and retaining device  1  in the housings  42  of a different width. Alternatively, it is possible to use a respective single model of bypass blocker  30 ,  31  in which the height of the ribs  32 ,  34  may be tailored to suit the width of the narrowest housing that is to be used, and with supplementary shaped parts fill gaps that occur when using these bypass blockers  30 ,  31  in a wider housing  42 . 
     The evaporator assembly  26  is now held in a sufficiently fixed manner in the housing  42  in order to solder the end pieces  58  of the refrigerant tube  29  to the already installed parts of the refrigerant circuit and to connect the evaporator heater  59  to a current supply. Once these tasks have been completed, a partition wall  62  may be inserted that lies against the ribs  60 ,  61  of the bypass blockers  30 ,  31  and subdivides the inner space  43  into a storage compartment for chilled goods and an evaporator chamber that receives the evaporator assembly  26 . 
     REFERENCE CHARACTERS 
     
         
           1  Retaining device 
           2  Base plate 
           3  Edge 
           4  Edge 
           5  Protrusion 
           6  Protrusion 
           7  Wall plate 
           8  Connecting piece 
           9  Connecting piece 
           10  Connecting piece 
           11  Recess 
           12  Corrugation 
           13  Section 
           14  Outer part 
           15  Outer part 
           16  Wall plate 
           17  Wall plate 
           18  Connecting piece 
           19  Connecting piece 
           20  Edge 
           21  Clip 
           22  Arm 
           23  Barbed hook 
           24  Condensed water channel 
           25  Through-going passage 
           26  Evaporator assembly 
           27  Evaporator 
           28  Fin 
           29  Refrigerant tube 
           30  Bypass blocker 
           31  Bypass blocker 
           32  Rib 
           33  Groove 
           34  Rib 
           35  Flank 
           36  Flank 
           37  Rear side 
           38  Front side 
           39  Insertion slope 
           40  Minimum 
           41  Recesses 
           42  Housing 
           43  Inner space 
           44  Side wall 
           45  Rear wall 
           46  Gap 
           47  Edge 
           48  Layer of insulating material 
           49  Inner vessel 
           50  Groove 
           51  Adhesive strip 
           52  Plug connector 
           53  Pin section 
           54  Drain 
           55  Head 
           56  Groove 
           57  Groove 
           58  End piece 
           59  Evaporator heater 
           60  Rib 
           61  Rib 
           62  Partition wall