Patent Publication Number: US-10775100-B2

Title: Domestic cooling device having a wall light, and method for producing the cooling device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a domestic cooling device which is equipped with a wall light for illuminating a cold chamber of the domestic cooling device. 
     2. Description of the Prior Art 
     Domestic refrigerators are typically provided with one or more lights, the purpose of which is to light a cold chamber of the refrigerator when the refrigerator door is open, so that the user has a better view of the foods stored in the cold chamber. A type of light that is conventionally used is a wall light, which is mounted on an insulating wall, adjoining the cold chamber, of an insulating housing of the refrigerator. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to show a way in which, in a domestic cooling device, a wall light can be produced in a structurally simple manner and with low production costs. 
     In order to achieve that object there is provided a domestic cooling device which comprises an insulating wall, a cold chamber adjoining the insulating wall, and a wall light arranged on the insulating wall for illuminating the cold chamber. The wall light comprises at least one light source, in particular of the LED type, a window element which forms a transparent window region through which light generated by the wall light emerges into the cold chamber, and a reflection surface, in particular having a diffusely reflecting action, which is arranged in front of the window element in the propagation path of at least a portion of the light radiation coming from the light source. The insulating wall comprises an inner lining part adjoining the cold chamber and an insulating foam material arranged behind the inner lining part. An opening is formed in the inner lining part, at least a portion of the reflection surface being arranged within the contour of the opening. According to the invention, at least a portion of the reflection surface is formed by a cover part which covers the opening and with which the insulating foam material is in contact. In particular, the reflection surface can be formed wholly by the cover part. 
     Particular embodiments of the invention are based on the idea of using a component that is conventionally employed in the production of the insulating wall, namely in the filling of a space situated behind the inner lining part with an insulating foam material, also to form the reflection surface of the wall light. In order to prevent the insulating foam material from escaping from the insulating wall through the opening during the foaming operation, a cover part which covers the opening is conventionally fixed to the inner lining part. According to the invention, such a cover part can serve as the reflector of the wall light. A separate, additional reflector is therefore unnecessary. This reduces the total number of components required and has an advantageous effect on the production costs of the wall light and of the cooling device as a whole. The cover part is, for example, a plastics component which, where it forms the reflection surface, can be designed with the surface condition required for the desired reflection behaviour. If the reflection surface (or at least a part-region thereof) is to have a scattering action, the cover part can be designed, for example, with a suitably matt appearance or/and a suitable surface roughness in the (part-)region of reflection surface. 
     In particular embodiments, the cover part is attached to the inner lining part from the side of the inner lining part that is remote from the cold chamber. The cover part can extend beyond the opening all round on the side of the inner lining part that is remote from the cold chamber. For example, the cover part can be fixed to the inner lining part by adhesive bonding means. The adhesive bonding means can comprise an adhesive by means of which the cover part is adhesively bonded directly to the inner lining part. Alternatively or in addition, the adhesive bonding means can comprise a tape material that is adhesive on one side or on both sides, by means of which it is possible to fix the cover part to the inner lining part. 
     In particular embodiments, the cover part forms a hollow, wherein at least a portion of the reflection surface, in particular substantially the entire reflection surface, is arranged in the hollow. By using techniques of injection moulding or deep drawing, there is wide scope in the configuration of the shape of the hollow. 
     In particular embodiments, the window region extends over at least a portion of the hollow. In order that the wall light protrudes only slightly from the inner lining part, it is advantageous if the light source and/or a circuit board on which the light source is mounted is arranged so that it is recessed at least in part, in particular substantially completely, in the hollow. 
     In particular embodiments, the hollow is in the form of a groove, wherein, when viewed in the groove cross-section, it has two opposite flank regions of different flank steepness. The light source can be arranged closer to the steeper of the two flank regions. If a plurality of light sources are present, they are arranged in a row spaced apart one behind the other in the longitudinal direction of the groove. 
     In particular embodiments, the light source and the window element are part of a preassembled light subassembly which is connected, in particular releasably connected, to the cover part from the side of the inner lining part that faces the cold chamber. The cover part itself is not part of the light subassembly; only when the light subassembly is attached to the inner lining part from the side thereof that faces the cold chamber does the cover part come into engagement with the light subassembly and be connected thereto. For example, the light subassembly or/and the cover part can be designed with at least one locking hook which engages behind a locking shoulder formed on the respective other component of the light subassembly and the cover part. 
     In particular embodiments, the wall light has a frame region which extends all round the window region and has a visible surface, facing towards the cold chamber, which contrasts visually with the window region, wherein the window region and the frame region are formed integrally in one piece and the frame region is formed of a different-coloured material to the window region or/and the visible surface has a different surface condition to the window region. Such an integral one-piece form of the window region and the frame region is also considered to be patentable on its own, independently of the use of the cover part as the reflector of the wall light. For example, the frame region and the window region can be manufactured from the same transparent plastics material, wherein the resulting plastics body is surface-treated, for example roughened, in the region of the visible surface in order to reduce or even completely eliminate the transparency in the region of the visible surface. 
     In particular embodiments, the wall light comprises a first light part which comprises at least the window element, in particular also the light source, and a second light part which is structurally separate from the first light part and forms at least a portion of the reflection surface. The second light part extends beyond the opening on the side of the inner lining part that is remote from the cold chamber, in particular all round. The first light part and the second light part are designed with cooperating connecting structures, which allow the two light parts to be releasably connected, for example interlocked, by attachment of the first light part to the second light part from the side of the inner lining part that faces the cold chamber. This aspect too, which is based on attaching the two light parts to the inner lining part not from the same side (namely the side that faces the cold chamber) of the inner lining part but from opposite sides of the inner lining part, is considered to be patentable on its own, independently of the use of the cover part as the reflector of the wall light. 
     The invention further provides a method which is used in the production of a domestic cooling device, in particular of a cooling device of the type described hereinbefore. The method comprises the steps: providing an inner lining part provided with an opening, a cover part, and a preassembled light subassembly which is separate from the cover part and comprises at least one light source and also a window element forming a transparent window region; fixing the cover part to a first side of the inner lining part so that the cover part covers the opening; attaching the light subassembly to the inner lining part from an opposite second side of the inner lining part in order to bring the light subassembly into holding engagement, in particular releasable holding engagement, with the cover part; and filling a space situated on the first side of the inner lining part with an insulating foam material so that the insulating foam material is in contact with the cover part. 
     The invention will be explained further hereinbelow with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows, schematically, a domestic cooling device according to a first exemplary embodiment. 
         FIG. 2  shows a light subassembly and a cover part as components of a wall light of the cooling device of  FIG. 1 . 
         FIG. 3  shows the wall light having the components of  FIG. 2  in a final mounted state. 
         FIG. 3 a    shows an enlarged detail of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will first be made to  FIG. 1 . The cooling device shown therein, which is intended for use in a private household, is designated generally  10 . The cooling device  10  serves for keeping foods cold above or/and below the freezing point. In the example shown, it is in the form of a cabinet and comprises a main housing  12  having a bottom wall  14 , a rear wall  16 , a top wall  18  and two mutually opposite side walls  20 , which together delimit a cold chamber  22  of the cooling device  10 . The cold chamber  22  can be equipped, in a manner which is not shown in detail but is generally known, with various built-in parts, for example shelves and drawers, which serve for storing the foods to be kept in the cooling device  10 . A door  24  by means of which the cold chamber  22  can be closed is pivotably mounted on the main housing  12 . 
     When the door  24  is open (as shown in  FIG. 1 ), it is desirable to illuminate the cold chamber  22  artificially, in order to provide the user with a better view of the foods therein. For this purpose, at least one wall light  26  is arranged on at least one of the walls  14 ,  16 ,  18 ,  20 , which wall light is so controlled that it is switched on and off depending on the opening and closing of the door  24 . In the example shown, one wall light  26  is arranged on the rear wall  16  and a further wall light  26  is arranged on the side wall  20  on the left in the representation of  FIG. 1 . It will be appreciated that the distribution pattern of the wall lights  26  shown in  FIG. 1  is purely by way of example and can be changed as desired in terms of both the number and the position of the wall lights  26 . It will additionally be appreciated that the wall lights  26  do not have to be the only lighting means with which the cooling device  10  is equipped. In addition to the wall lights  26 , lighting means of different forms can be provided. Such different types of lighting means are not subject-matter of the present disclosure and require no further explanation. 
     For further details of the wall lights  26 , reference will now additionally be made to  FIGS. 2, 3 and 3   a , which are sectional representations of one of the wall lights  26 , on the one hand broken down into individual components ( FIG. 2 ) and on the other hand in the final mounted state ( FIGS. 3 and 3   a ). According to the exemplary embodiment of  FIGS. 2, 3 and 3   a , the wall light  26  comprises a light subassembly  28  which can be preassembled, which is also referred to hereinbelow as a lighting module. The lighting module  28  forms a first light part within the meaning of the invention and comprises a plurality of light sources  32  (e.g. white-light LEDs) arranged in a row spaced apart one behind the other on a circuit board  30 , and a module body  34  to which the circuit board  30  is releasably or permanently fixed, for example by a snap-action connection or a press-fit connection. The row of light sources  32  extends perpendicularly to the plane of the drawing of  FIGS. 2 and 3 . The module body  34  forms a plate- or disc-like window element  36  made of a transparent material. The window element  36  in turn forms a window region  38 , within which light from the wall light  26  is able to emerge. The window region  38  is surrounded all round by a frame region  40 , in which the module body  34  forms a visible surface  42  which contrasts visually with the window region  38 . The visible surface  42  extends all round the window region  38  and, from the point of view of the user, represents an outside border of the window region  38 . This ensures an aesthetically pleasing design of the wall light  26 . In the example shown, the module body  34  is a one-piece component which comprises both the window region  38  and the frame region  40 . In the window region  38 , the module body  34  can be, for example, in the form of a transparent body with a transmission of 90% or 95% or more for visible light. Alternatively, the module body  34  can have a milky (opaque) appearance in the window region  38 . 
     In the frame region  40 , the module body  34  can consist of the same material as in the window region  38 , whereby, in order to achieve the desired visual contrast between the visible surface  42  and the window region  38 , the visible surface  42  can have been subjected to a surface treatment. The surface treatment can comprise, for example, a coating with a coloured lacquer or with a coating having a metallic appearance (galvanisation). Alternatively, the frame region  40  can have been subjected to roughening of its surface in the region of the visible surface  42  so that the transparency in that region is reduced or even eliminated completely as compared with the window region  38 . 
     Another possibility consists in producing the module body  34  from plastics materials of different kinds in a multi-component injection-moulding process, a transparent plastics material being used for the window region  38  and a non-transparent plastics material being used for the frame region  40  and any other regions of the module body  34 . 
     A further component of the wall light  26  is a cover part  44 , which is separate from the lighting module  34  and forms a hollow  46  in which the circuit board  30  with the light sources  32  mounted thereon is received when the wall light  26  is assembled. In the final mounted state, the wall light  26  is arranged on an insulating wall  48  ( FIG. 3 ), which is one of the walls  14 ,  16 ,  18 ,  20  which delimit the cold chamber  22  of the cooling device  10  of  FIG. 1 . For example, the insulating wall  48  is the rear wall  16  or one of the side walls  20 . The insulating wall  48  is of multi-layer construction and comprises an inner lining part  50 , an outer lining part  52  and an insulating foam material  54  which fills a space between the inner lining part  50  and the outer lining part  52  and is the result of a foaming operation in which the mentioned space is filled with foam by means of a suitable, often liquid starting product. The cover part  44 , which can also be referred to as a cover cap, has a dual function. It serves to cover an opening  56  formed in the inner lining part  50  during the foaming operation so that no insulating foam escapes from the insulating wall  48  through the opening  56 . In addition, the cover part  44  forms a reflection surface  58  of the wall light  26 , which is irradiated by at least a portion of the light radiation generated by the light sources  32  and effects diffuse reflection (scattering) of that light radiation. This scattering action is illustrated graphically in  FIG. 3  by broken arrows  60 . 
     The cover part  44  forms a second light part within the meaning of the invention and has an edge portion  62  running all round the opening  56 , with which the cover part  44  is attached to the inner lining part  50  on the side thereof that is remote from the cold chamber. In this manner, the opening  56  is covered completely by the cover part and closed. The surfaces at which the edge portion  62  and the inner lining part  50  are in contact with one another can be provided with an adhesive in order to fix the cover part  44  to the inner lining part  50 . Alternatively or in addition, adhesive strips of tape material can be used for fixing the cover part  44  to the inner lining part  50 . In the subsequent final mounted state, it is not possible to remove the cover part  44  from the cold chamber  22  without damaging the wall light  26 . Only the lighting module  28  can be removed from the cold chamber  22 , for example in order to allow the circuit board  30  to be replaced if one or more of the light sources  32  mounted thereon have failed. 
     An arrangement of one or more locking hooks  64  is formed on the module body  34  or/and on the cover part  44 . In the example shown, a plurality of such locking hooks  64  are formed on the module body  34 . Each locking hook has a hook nose  64 - 1  with which the locking hook  64  in question snaps behind a locking shoulder  65  (see in particular  FIGS. 2 and 3   a ) formed on the cover part  44  when the wall light  26  is assembled (i.e. when the lighting module  28  is attached to the inner lining part  50  from the side of the cold chamber  22 ) and thereby connects the lighting module  28  to the cover part  44 . The locking connection between the lighting module  28  and the cover part  44  can be releasable so that, if required, for example if one of the light sources  32  fails, the lighting module  28  can be removed from the cover part  44  and thus from the insulating wall  48  and the faulty light source  32  can be replaced. Each locking hook  64  is, for example, in the form of a flexibly deflectable locking tongue which, when the lighting module  28  and the cover part  44  are fitted together, first deflects resiliently before the hook nose  64 - 1  snaps behind the locking shoulder  65 . It will be recognised that, when the wall light  26  is mounted, the frame region  40  of the module body  34  comes to lie on the side of the inner lining part  50  that faces the cold chamber so that, in the final mounted state, the inner lining part  50  is enclosed between the edge portion  62  of the cover part  44  and the edge region  40  of the module body  34 . The locking connecting means (i.e. the locking hooks  64  engaging behind the locking shoulder(s)  65 ) acting between the module body  34  and the cover part  44  are in particular in such a form that the inner lining part  50  is clamped under pressure between the frame region  40  and the edge portion  62 . 
     During production of the refrigerator  26 , the space between the inner lining part  50  and the outer lining part  52  is only filled with foam once the cover part  44  has been positioned over the opening  56  on the inner lining part  50  and fixed thereto. The lighting module  28  can likewise be inserted into the opening  26  and connected to the cover part  44  before the foaming operation. It is, however, also possible to mount the lighting module  28  on the insulating wall  48  only after the foaming operation. The insulating foam material  54  reaches right up to the cover part  44  and covers it substantially completely on the side of the cover part  44  that is remote from the cold chamber  22 . 
     The hollow  46  of the cover part  44  is in the form of a groove-like depression which has a substantially constant groove cross-section in the groove longitudinal direction and, when viewed in the groove cross-section (according to the representation of  FIGS. 2 and 3 ), has a groove bottom  66  and two groove flanks  68 ,  70  laterally adjoining the groove bottom  66 . The groove flank  68  is considerably steeper than the groove flank  70  and, in the example shown in  FIGS. 2 and 3 , extends substantially perpendicularly to the wall plane of the insulating wall  48 . The groove flank  70 , on the other hand, follows a path which at least for the large part is curved in an arcuate manner. The row of light sources  32  extends in the groove longitudinal direction of the hollow  46 , the light sources  32  being arranged closer to the steeper groove flank  68  than the groove flank  70 . The reflection surface  58  is formed in the region of the groove bottom  66  and the groove flank  70 . 
     The circuit board  30  is so oriented that a portion of the light radiation emitted by the light sources  32  first strikes the reflection surface  58 , where it is scattered. Only then does the resulting scattered radiation (represented by the arrows  60 ) leave the wall light  26  through the window region  38 . Another portion of the light radiation emitted by the light sources  32  strikes the window region  38  directly, as is illustrated in  FIG. 3  by two solid arrows  72 . This portion of the light radiation, depending on the angle of incidence, can leave the wall light  26  directly through the window region  38 , or it may undergo total reflection at the side of the window element  36  that is remote from the cold chamber and be reflected back in the direction towards the reflection surface  58 , where it is scattered. 
     Because the reflection surface  58  is provided directly on the cover part  44 , the wall light  26  does not require a separate reflector body, which would have to be provided in addition to the cover part  44 . This lowers the outlay for the wall light  26  in terms of components and reduces the production costs thereof. 
     Although the preferred embodiments of the present invention have been described herein, the above description is merely illustrative. Further modification of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention as defined by the appended claims.