Abstract:
A water filter assembly for a refrigeration appliance contains an inlet connection, a filter head, on which a water filter can be mounted, a non-return valve and an outlet connection. The non-return valve is connected to the water filter by way of a hose. The hose can be attached to a connection of the filter head which is already available to feed or drain water, without adjustments to the filter head being required for this purpose.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the priority, under 35 U.S.C. §119, of German application DE 10 2016 212 531.1, filed Jul. 8, 2016; the prior application is herewith incorporated by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The present invention relates to a water filter assembly for a refrigeration appliance, in particular a domestic refrigeration appliance, such as a refrigerator or a fridge-freezer which is connected to a water supply network for supplying a cold water dispenser integrated in the refrigeration appliance, an ice maker or such like. 
         [0003]    Such refrigeration appliances must be protected against the back-flow of water out of the appliance into the supply network by a non-return valve. 
         [0004]    Published, non-prosecuted South Korean patent application KR 10 2009 007 7392 A discloses a water filter assembly for a refrigeration appliance, in which a non-return valve is integrated in a filter head in which a filter cartridge is releasably fixed. Since the filter head has to have apertures both for the fresh water to access the filter cartridge and also to drain the filtered water and means for fixing the filter cartridge, it has a complicated design and is correspondingly costly to manufacture, and the integration of the non-return valve necessitates expensive changes to the tools used to manufacture the filter head. If additional space required for the non-return valve cannot be provided in the case of a filter head with a compact structure without changing the external design of the filter head, even consequential changes to the housing of a refrigeration appliance in which the filter head is installed may be necessary. 
       SUMMARY OF THE INVENTION 
       [0005]    The object of the present invention is to create a water filter assembly with an integrated non-return valve, which can be realized in a cost-effective manner and the installation of which in an existing refrigeration appliance housing requires no or at the most minimal adjustments to the housing. 
         [0006]    The object is achieved on the one hand by the non-return valve being connected to the filter head by way of a hose in the case of a water filter assembly with an inlet connection, a filter head, on which a water filter can be mounted, a non-return valve and an outlet connection. 
         [0007]    The hose can be attached to a connection of the filter head which is already available to feed or drain water, without adjustments to the filter head being required for this purpose; an existing filter head can therefore be further used unmodified in the inventive water filter assembly. The hose has the freedom of positioning the non-return valve at a point in the refrigeration appliance at which its space requirement can be freed up relatively easily and without the need to adjust components which are complicated and expensive to manufacture. 
         [0008]    In principle the non-return valve could be inserted into the hose at any point; one end of the hose is however preferably provided at the point selected for the non-return valve and at this end of the hose a coupling element for connecting the hose to a subsequent line which does not form part of the assembly is provided; the non-return valve is then easy to mount in a through hole in the coupling element by insertion from one open end. 
         [0009]    The water filter assembly can be supplied pre-assembled with an inserted non-return valve for refrigeration appliance manufacture, since the filter head and non-return valve are subsequently installed together, one assembly step can be saved when assembling the inventive refrigeration appliance. 
         [0010]    The coupling element preferably forms the inlet connection of the assembly, therefore the non-return valve can also separate the filter from the supply network. 
         [0011]    In a first direction, the non-return valve can be secured in the through hole by a blocking ring supported in a groove of the through hole; in particular to prevent the non-return valve from falling out of the through hole before installing the water filter assembly in a refrigeration appliance. 
         [0012]    The first direction is preferably opposite to the flow direction of the water so that the blocking ring does not have to withstand the water pressure. 
         [0013]    To secure the non-return valve from falling out prior to installation of the water filter assembly, it may also be sufficient if the non-return valve is held or clamped in the through hole in a frictionally engaged manner. 
         [0014]    In a second direction, the non-return valve is secured in the through hole preferably by narrowing the through hole. Such a safety catch can reliably hold the non-return valve in place also against the water pressure. 
         [0015]    The subject matter of the invention is also a refrigeration appliance, in particular a domestic refrigeration appliance, with a water filter assembly as described above. 
         [0016]    With such a refrigeration appliance, the inlet connection of the water filter assembly can be accessible from the outside of the refrigeration appliance, in order to be directly connected to the water supply network of a building. 
         [0017]    Alternatively the inlet connection of the water filter assembly can be connected to an outer inlet connection of the refrigeration appliance by way of a supply line fixed to the appliance, the non-return valve can then be secured in the through hole against the flow direction of the water by a coupling at the downstream end of the supply line fixed to the appliance. 
         [0018]    Other features which are considered as characteristic for the invention are set forth in the appended claims. 
         [0019]    Although the invention is illustrated and described herein as embodied in a water filter assembly and a refrigeration appliance equipped therewith, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
         [0020]    The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0021]      FIG. 1  is a diagrammatic, sectional view of a water filter assembly according to the invention; 
           [0022]      FIG. 2  is a longitudinal sectional view through a coupling element of the water filter assembly; 
           [0023]      FIG. 3  is a schematic vertical sectional view through a carcass or body of a refrigeration appliance; 
           [0024]      FIG. 4  is an alternative sectional view through the carcass of the refrigeration appliance; 
           [0025]      FIG. 5  is a longitudinal sectional view through the coupling element connected to a line of the refrigeration appliance which is fixed thereto; 
           [0026]      FIG. 6  is a longitudinal sectional view, which is similar to  FIG. 2 , according to a second embodiment of the invention; and 
           [0027]      FIG. 7  is a longitudinal sectional view, which is similar to  FIG. 2 , according to a third embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    Referring now to the figures of the drawings in detail and first, particularly to  FIG. 1  thereof, there is shown a water filter assembly for installation in a refrigeration appliance. A filter head  2  has a supporting molding  3  on one side, in which a water filter  4  is screwed or is fixed in a releasable and water tight manner by a bayonet coupling, and two connecting studs  5 ,  6 , to which hoses  7 ,  8  are fastened, on the opposing side. The water filter  4  has a cup-shaped housing  9 , on the longitudinal axis of which a repeatedly perforated tube  11  surrounded by a porous filter element  10  extends flush with the connecting stud  6 . The hose  8  is connected to the interior of the pipe  11  by way of the connecting stud  6 , the hose  7  by way of the connecting stud  5  with a clearance  12  which annularly surrounds the filter element  10  in the housing  9 . A coupling element  13  on the end of the hose  7  facing away from the filter head  2  forms an inlet connection  14  of the filter assembly. A screw thread  15  at the end of the coupling element  13  facing away from the hose  7  is provided in order to screw together with a line supplying water. 
         [0029]      FIG. 2  shows a longitudinal section through the coupling element  13 . The coupling element  13  has a through hole  16  with a wide section  17  which opens toward the end of the coupling element facing away from the hose  7  and a narrow section  19  which is separated from this by a narrowing  18  and engages in the hose  7 . 
         [0030]    A non-return valve  20  is inserted into the wide section  17  from the open end and is secured by a blocking ring  21  which engages in a circumferential groove on the wall of the wide section  17 . The non-return valve  20  in the water filter assembly is already secured in a non-volatile manner by the blocking ring  21  before its installation in a refrigeration appliance; the water filter assembly is therefore well suited to being supplied completely pre-assembled and for the refrigeration appliance manufacture at a location which is remote from the manufacture of the refrigeration appliance, particularly in the case of an outside supplier. 
         [0031]    The non-return valve  20  has an annular valve seat  22  with a circumferential groove. A sealing ring  23  accommodated in the groove blocks a gap between the valve seat  22  and the surrounding wall of the coupling element  13 . A closing element  25  and a spring  26  which forces the closing element  25  against the valve seat  22  are accommodated in a basket  24  which projects from the valve seat  22  in the through direction of the water. 
         [0032]      FIG. 3  shows a schematic section through a household refrigeration appliance equipped with the water filter assembly in  FIG. 1  according to a first embodiment of the invention. Here the hose  7  is placed fixedly in the appliance and extends through a thermal insulation layer  27  of the appliance between the coupling element  13  which is accessible on the outside of a rear wall of the appliance on the one hand and the filter head  2  and the water filter  4  on the other hand, which are arranged in a cooled interior  28  of the appliance which is enclosed by the thermal insulation layer  27 . The coupling element  13  is connected to the water supply network  30  by way of a hose  29  which runs outside of the appliance. 
         [0033]    The hose  8  runs from the filter head  2  through the thermal insulation layer  27  to a distributor valve assembly  31  in the machine compartment  32  of the appliance. Lines emanating therefrom lead to an ice maker  33  and via a cooled storage tank  34 , to a water dispenser  35 . 
         [0034]    In the embodiment in  FIG. 4 , the hoses  7 ,  8  of the water filter assembly only extend up to coupling elements  13 ,  36  in the cooled interior  28  of the appliance and are connected to lines  37 ,  38  running fixedly in the walls thereof, of which the one  37  leads to a coupling  39  accessible on the rear side of the appliance and connected to the water supply network  30  and the other  38  to the distributor valve assembly  31 . With this embodiment, installation of the water filter assembly can be postponed until the housing of the appliance including the thermal insulation layer  27  is completely assembled. 
         [0035]    In this embodiment the blocking ring  21  may not be necessary and its object of immobilizing the non-return valve  20  against the flow direction of the water, as shown in  FIG. 5 , can be taken over by a coupling element  40  of the line  37  which complements the coupling element  13  and is screw-connected here, the through hole  41  of which is narrower than the diameter of the non-return valve  20 . In order to secure the non-return valve  20  in the coupling element  13  until installation of the water filter assembly, a frictional connection of the sealing ring  23  in the through hole  16  or another type may be sufficient to clamp the non-return valve  20  in the through hole  16 . 
         [0036]      FIG. 6  shows a longitudinal section through a coupling element  13 ′ according to a second embodiment of the invention. The outer design of the coupling element  13 ′ is identical to the coupling element  13  in  FIG. 2  and in both figures the same reference characters refer to identical components. The groove and the blocking ring  21  at the open end of the through hole  16  are not required here; instead, the non-return valve  20  is secured against leaking through the open end, by, after inserting the non-return valve  20 , a tool having been pressed into the open end, said tool molding axial grooves  42  in the wall of the wide section  17  and the material displaced in the process having been pushed together to form projections  43  which obstruct the passage of the non-return valve  20 . 
         [0037]      FIG. 7  shows a longitudinal section through a coupling element  13 ″ according to a second embodiment of the invention. In turn the same reference characters refer to components which are identical to those of the embodiments described above. 
         [0038]    The distance between the screw thread  15  and the narrowing  18  is enlarged here in order to create space for a thin-walled pipe section  44 . After inserting the non-return valve  20  this pipe section  44  is compressed locally in order to mold projections  45  engaging in the wide section  17  of the through hole  16  which secure the non-return valve  20  in a form-fit manner. The non-return valve  20  can be axially extended as shown in the  FIG. 7  so that the projections  45  on the circumference of the non-return valve  20  can engage between the sealing ring  23  and a second projecting ring  46 , worth considering however is also to make the pipe section  44  so long that the projections  45  such as the projections  43  in  FIG. 6  engage between the non-return valve  20  and the open end into the through hole  16 . The coupling element  13 ″ is however less compact than the coupling elements  13  or  13 ′, but is advantageous compared with the coupling element  13 ′ in that there is no risk of negatively affecting a sealing surface  47  which extends around the open end by molding the projections  45 . 
         [0039]    The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:
     1  Water filter assembly     2  Filter head     3  Supporting molding     4  Water filter     5  Connecting stud     6  Connecting stud     7  Hose     8  Hose     9  Housing     10  Filter element     11  Pipe     12  Clearance     13  Coupling element     14  Inlet connection     15  Screw thread     16  Through hole     17  Wide section     18  Narrowing     19  Narrow section     20  Non-return valve     21  Blocking ring     22  Valve seat     23  Sealing ring     24  Basket     25  Closing element     26  Spring     27  Thermal insulation layer     28  Interior     29  Hose     30  Water supply network     31  Distributor valve assembly     32  Machine compartment     33  Ice maker     34  Storage tank     35  Water dispenser     36  Coupling element     37  Line     38  Line     39  Coupling     40  Coupling element     41  Through hole     42  Groove     43  Projection     44  Pipe section     45  Projection     46  Ring     47  Sealing surface