Patent Publication Number: US-10317129-B2

Title: Refrigerator shelf with overflow protection system including hydrophobic layer

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application Ser. No. 61/570,509, filed Dec. 14, 2011 and claims the benefit under 35 U.S.C. § 119(a) of German Patent Application No. 10 2011 085 428.2, filed Oct. 28, 2011. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an shelf, in particular an shelf for a refrigerator. 
     2. Description of Related Art 
     Refrigerator shelves consist, as a rule, of a grid or of a glass pane which is provided with mechanical elements for holding in a refrigerator. Glass panes are distinguished not only by the advantage of better stability of the refrigerated stock, as compared with grids, but also, inter alia, in that liquids running out can be captured by the pane, so that contamination of the lower-lying region of the refrigerator can be avoided. Lateral overflow of liquids can in this case be avoided in various ways. 
     A customary solution for overflow protection consists of a plastic frame which surrounds the glass pane on all sides and which forms a margin around the pane. The disadvantage is that a plastic margin of this type is complicated to produce and reduces the standing surface which can be used for the refrigerated stock. Furthermore, the peripheral frame makes it difficult to clean the refrigerator shelf. 
     EP 0859207 proposes to provide a glass pane with arching so that an overflow volume of at least 100 cm 3  can be accommodated before overflow occurs. At the same time, a frame around the glass pane may be dispensed with. However, achieving the arching according to the invention entails an additional complicated process step in production. 
     The object of the invention is to provide an shelf for a refrigerator, having overflow protection, which is improved in relation to the prior art. 
     SUMMARY OF THE INVENTION 
     The following description of the invention assumes that the shelf according to the invention and the overflow protection are in an installed state, so that, as seen by a user, this has a top side, an underside and also front, rear and side edges. 
     The shelf according to the invention comprises a carrier plate and overflow protection, the top side of the carrier plate having a middle region for standing containers and the overflow protection being arranged around the middle region. The shelf is characterized in that the overflow protection is designed, in a first portion, in the form of a hydrophobic layer on the carrier plate and, in a second portion which adjoins the first portion, comprises a frame element. 
     The carrier plate is preferably a plane glass plate with a material thickness of 3 to 8 mm. It is preferably commercially available prestressed float glass, that is to say a soda-lime glass. However, the carrier plates may also consist likewise of glass ceramic, plastic or metal or combinations of the materials mentioned. 
     In the middle region of the carrier plate, the carrier plate preferably has no coating, although the middle region may also be coated. However, the coating should have no hydrophobic properties, since the effectiveness of the hydrophobic layer of the overflow protection is thereby reduced. 
     The first and the second portion may, in general, extend in each case only over a small fraction of the circumference of the carrier plate, for example part of one side of the carrier plate, or else over a large fraction of the circumference of the carrier plate, for example over several sides of the carrier plate. 
     The hydrophobic layer may be any hydrophobic layer system which has sufficient resistance to chemicals and sufficient mechanical strength. Suitable layer systems are known to a person skilled in the art. 
     A typical example of a hydrophobic layer system is the inorganic/organic hybrid polymers which are known under the trade mark ORMOCER® of the Fraunhofer Institute for Silicate Research. On the other hand, there is a multiplicity of hydrophobic organic solutions which can be applied after manufacture or else by the final customer, for example a group of solutions which have become known under the trade mark “Clear Shield®”. 
     DE 100 18 671 A1 likewise discloses a suitable hydrophobic coating on glass or ceramic material, the said coating having an especially high mechanical strength. It comprises a thin underlayer composed of a metal compound, in particular of inorganic or organic compounds with preferably trivalent or tetravalent metals, such as Si, Al, Ti and Zr, and also an outer hydrophobic organic layer composed of siloxane, silane, fluorosilanepolyurethane or tetrafluoropolyethylene. 
     The hydrophobic layer exerts its action as overflow protection essentially on account of its special hydrophobicity, not because of its vertical extent. Depending on the intensity of hydrophobicity and on the strength of the liquid, a hydrophobic layer may, as a liquid barrier, have the effect of a mechanical barrier of a height of approximately 5 mm or more, although it may have a height of markedly less than 1 mm. 
     The hydrophobic layer may be of transparent or else coloured form. 
     A frame element is to be understood in general to mean a mechanical element which, essentially on account of its vertical extent, constitutes a barrier to liquid running out. It may be, for example, a plastic strip which is glued to the carrier plate or a profile strip which is plugged onto the side edge of the carrier plate and projects vertically above the surface of the carrier plate. 
     The overflow protection may comprise only the first and the second portion, but also further portions which, together with the first and the second portion, form the overflow protection. The overflow protection preferably surrounds the middle region of the carrier plate completely. 
     The hydrophobic layer is preferably arranged along the outer margin of the carrier plate in the form of a band with a width of 0.5 to 5 cm and in each case runs parallel to one of the outer edges of the carrier plate. It may, however, also be arranged at a distance from the outer edge. 
     The hydrophobic layer preferably has a layer thickness of 5 nm to 100 μm. There is therefore no or only a slight height difference with respect to the uncoated region of the carrier plate and therefore the surface having the hydrophobic layer can be utilized fully as a standing surface. 
     In a preferred embodiment, the hydrophobic layer is arranged in the form of an adhesive tape on the carrier plate, thus making it possible to apply the layer in an especially simple way. 
     Preferably no frame element or other element which projects vertically above the surface of the hydrophobic layer is arranged in the first portion, that is to say the hydrophobic layer alone acts as overflow protection. 
     In the second portion in which the overflow protection comprises a frame element, the frame element is preferably arranged along the outer edge of the carrier plate and is connected, liquid-tight, to the carrier plate. The frame element may in this case be arranged only on the top side of the carrier plate or else may extend, preferably in the form of a profile strip, around the outer edge of the carrier plate. The liquid-tight connection may in this case be designed, for example, in the form an unreleasable adhesive bond or else in the form of a sealing lip which makes it possible to release the frame element. This makes it possible, inter alia, to clean the frame element thoroughly in a simple way. 
     The frame element preferably projects vertically above the top side of the carrier plate by a height H of 1.0 mm or more. The frame element especially preferably projects above the top side of the carrier plate by 2.0 to 20.0 mm. The frame element can at the same time fulfil further functions in addition to its function as overflow protection. A frame element on the front side of the shelf may be designed as a grip part for pulling out the shelf, for example by means of a lip arranged on the underside. A frame element on the side of the shelf may be designed as a lateral guide rail which, together with a correspondingly designed guide in the refrigerator, forms a rest for the shelf. A frame element on the rear side may be designed as a rear shelf boundary which delimits the standing surface to the rear. 
     The frame element or part of the frame element may be designed to be removable, so that liquid captured by the overflow protection can be discharged in a controlled way. The removable part of the frame element may have, for example, a width of 0.5 cm to 5 cm and be contrasted in colour and/or shape from the frame element. The frame element may likewise extend over the entire front edge of the carrier plate and be designed to be removable. If liquid has run out and been captured by the overflow protection, it is generally difficult to remove the liquid from the shelf within the confined inner space of the refrigerator. It is also not readily possible to take out the shelf, since, even when the shelf is tilted only slightly, the liquid may overflow. In the proposed solution, a collecting container is arranged under the removable part of the frame element and the removable part is removed so that the liquid flows off into the container. The proposed solution thus makes it possible in a simple way to discharge at least some of the liquid which has run out, so that the removal of the liquid is, overall, conveniently possible. In this preferred embodiment, the carrier plate may have a slight inclination of 1° to 8°, preferably 2° to 5°, with respect to the horizontal, the removable part of the frame element lying at the lowest point, so that a large part of the liquid can be discharged in a controlled way. The inclination in this case relates to an installed state of the shelf, with the refrigerator oriented horizontally. 
     In a second portion, too, in which the overflow protection comprises a frame element, a hydrophobic layer may additionally be arranged between the frame element and the middle region, so that the frame element is protected from impurities. 
     The overflow protection has, as seen by a user, a front-side portion, a rear-side portion and two lateral portions, the front-side portion being located on the side facing the user and the rear-side portion being located on the side facing away from the user. 
     In a preferred embodiment, the lateral portions of the overflow protection are designed, essentially over their entire length, as a hydrophobic layer, and the front-side and/or rear-side portion comprise/comprises, essentially over the entire length, a frame element. Essentially is to be understood in this context to mean a length fraction of at least 50%, but preferably 80% or more, preferably only the transition regions arranged in the corners being accepted. This shelf has an especially wide standing surface. It has, furthermore, the advantage that, in the region of the especially stressed front edge of the shelf, the frame element at the same time protects the front edge of the carrier plate from shocks, for example when the refrigerator is being loaded with bottles. Moreover, no wear of the frame profile occurs during frequent loading and unloading. By contrast, when there is a hydrophobic coating in the region of the front edge, there is the risk that this becomes worn as a result of frequent loading and unloading and its effectiveness diminishes. 
     The hydrophobic layer is therefore preferably arranged only in the surface regions of the shelf which are at less risk of abrasion. 
     In a further preferred embodiment, the lateral portions of the overflow protection comprise, essentially over their entire length, a frame element, and the front-side and/or rear-side portion are/is designed, essentially over their entire length, as a hydrophobic layer. Essentially is to be understood in this context to mean a length fraction of at least 50%, but preferably 80% or more, preferably only the transition regions arranged in the corners being accepted. The shelf consequently affords an especially deep standing surface. In this embodiment, the lateral frame elements preferably serve at the same time for guiding and holding the shelf, so that further carrying elements, such as, for example, angle pieces arranged under the shelf, may be dispensed with. 
     In a first embodiment, in a transition region between a first portion, in which the overflow protection is designed in the form of a hydrophobic layer on the carrier plate, and a second portion, which adjoins the first portion and in which the overflow protection comprises a frame element, the hydrophobic layer runs as far as the lower edge of the frame element or underneath the frame element. In the first instance, therefore, the hydrophobic layer directly adjoins the frame element and is delimited by this. Consequently, in the case of a minimal extent of the transition region, the first and the second portion adjoin one another. In the latter instance, the hydrophobic layer extends from the first portion beneath the frame element in the transition region, that is to say is arranged in the transition region between the carrier plate and frame element. Exact delimitation of the hydrophobic layer signifying a higher outlay in manufacturing terms can thereby advantageously be dispensed with. 
     In a further embodiment of the transition region between a first portion and a second portion, the hydrophobic layer runs from the first portion as far as the lower edge of the frame element and is then continued in the transition region on the rising edge of the frame element. This embodiment ensures that a transition region does not constitute in the overflow protection a weak point where liquid preferentially runs out. 
     Particularly in this embodiment of the transition region, the hydrophobic layer may be arranged on an adhesive tape which can be glued to the carrier plate and to the frame element. 
     The invention relates, furthermore, to a carrier plate according to the same inventive principle. 
     The carrier plate according to the invention has overflow protection which is arranged along the circumference of the carrier plate, the overflow protection being designed, in a first portion, in the form of a hydrophobic layer on the carrier plate and, in a second portion which adjoins the first portion, comprising a frame element. The carrier plate may be designed, for example, as a worktop, table top, cutting board, cooking hob, cooking pocket, oven lid or shop counter or a component of these. It may be, in particular, a cooking hob made from glass or glass ceramic. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention, then, is explained in more detail by means of  FIGS. 1 to 4 . 
         FIG. 1  shows a perspective illustration of a first preferred embodiment. 
         FIG. 2  shows a cross-sectional illustration of the embodiment illustrated in  FIG. 1 , in the sectional plane A-A. 
         FIG. 3A  shows a perspective illustration of further preferred embodiments. 
         FIG. 3B  shows a perspective illustration of further preferred embodiments. 
         FIG. 3C  shows a perspective illustration of further preferred embodiments. 
         FIG. 3D :  Figure 3D  shows a perspective illustration of further preferred embodiments. 
         FIG. 3E  shows a perspective illustration of further preferred embodiments. 
         FIG. 3F  shows a perspective illustration of further preferred embodiments. 
         FIG. 4A  shows a cross-sectional illustration of the transition region between a hydrophobic layer and a frame element in several embodiments. 
         FIG. 4B  shows a cross-sectional illustration of the transition region between a hydrophobic layer and a frame element in several embodiments. 
         FIG. 4C  shows a cross-sectional illustration of the transition region between a hydrophobic layer and a frame element in several embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following figure description assumes that the refrigerator shelf according to the invention is in an installed state, so that, as seen by the user of the refrigerator, it has a top side, an underside and also front, rear and side edges. 
       FIG. 1  shows a shelf ( 1 ) for a refrigerator according to a first preferred embodiment of the invention. In this embodiment, a frame element ( 22 ) is formed at the front edge and forms the front-side portion ( 7 ) of the overflow protection, and a frame element ( 22 ) is formed at the rear edge of the carrier plate and forms the rear-side portion ( 8 ) of the overflow protection, the said frame element extending respectively over the full length of the front edge and the rear edge. A band ( 13 ) of a hydrophobic layer ( 12 ) extends along each of the two sides of the carrier plate ( 2 ). The frame element ( 22 ), which constitutes the front-side portion ( 7 ) of the overflow protection, is designed in the form of a profile strip which is plugged onto the front edge of the carrier plate ( 2 ). This profile strip is designed at the same time as a grip element as a result of a lip on the underside of the frame profile, in order to make it possible to pull out the shelf ( 1 ). The frame element ( 22 ) which constitutes the rear-side portion ( 8 ) of the overflow protection is likewise designed in the form of a profile strip which is plugged onto the rear edge. The useful standing surface of the carrier plate ( 2 ) is consequently delimited mechanically on the rear side. 
     The shelf ( 1 ) comprises, for example, angle pieces as fastening elements ( 14 ) which are arranged under the carrier plate and which serve for holding the shelf, for example, in a refrigerator. However, the type of fastening is of minor importance for the subject of the invention, and the fastening illustrated is therefore to be understood as being merely by way of example. 
       FIG. 2  shows a cross-sectional illustration of the embodiment illustrated in  FIG. 1 , in the sectional plane A-A according to  FIG. 1 . The frame element which constitutes the front-side portion ( 7 ) of the overflow protection has essentially a U-shape and, furthermore, possesses on the underside a lip which serves as a grip element for pulling out the shelf ( 1 ). The rear margin element likewise has essentially a U-shape and possesses on the top side a lip which delimits the rear boundary of the standing surface visually and mechanically. 
       FIGS. 3A-3F  show further preferred embodiments in perspective illustrations. The illustration of the carrier elements which are not essential to the invention has been dispensed with, so that in each case only the carrier plate ( 2 ) and the overflow protection are illustrated. Exactly as in the perspective illustration in  FIG. 1 , the front-side part, facing the user, of the shelf is located in each case at the bottom right and the rear-side portion therefore at the top left. 
     In the embodiment according to  FIG. 3A , a frame element ( 22 ) is formed at the front edge of the carrier plate ( 2 ) and extends over the entire length of the front edge. A band ( 13 ) of a hydrophobic layer ( 12 ) extends along both sides and also the rear side of the carrier plate ( 2 ), so that the said layer has overall a U-shape. In the embodiment according to  FIG. 3B , a frame element ( 22 ) is formed at the rear edge of the carrier plate ( 2 ) and extends over the entire length of the rear edge. A band ( 13 ) of a hydrophobic layer ( 12 ) extends along both sides and also the front edge of the carrier plate ( 2 ), so that the said layer has overall a U-shape. The frame element which constitutes the rear-side part of the overflow protection is designed in the form of a profile strip which is plugged onto the rear edge. In the embodiment according to  FIG. 3C , a frame element is formed at the side edges of the carrier plate and extends in each case over the entire length of the side edges. A band of a hydrophobic layer extends in each case along the front-side and the rear-side edge of the carrier plate. The frame elements which constitute the lateral parts of the overflow protection are designed in the form of profile strips which are plugged onto the side edge. The lateral frame elements serve at the same time for guidance during pushing into a refrigerator. In the embodiment according to  FIG. 3D , a frame element is formed at the side edges of the carrier plate and at the rear edge and extends in each case over the entire length of the edges. A band of a hydrophobic layer extends along the front-side edge of the carrier plate. The frame elements are designed in the form of profile strips and form a coherent U-shaped profile. The lateral frame elements serve at the same time for guidance during pushing into a refrigerator. In the embodiment according to  FIG. 3E , a frame element is formed at the side edges of the carrier plate and at the front edge and extends in each case over the entire length of the edges. A band of a hydrophobic layer extends along the rear-side edge of the carrier plate. The frame elements are designed in the form of profile strips and form a coherent U-shaped profile. The lateral frame elements serve at the same time for guidance during pushing into a refrigerator. 
     In the embodiment according to  FIG. 3F , a frame element is formed at the front edge and forms the front-side portion ( 7 ) of the overflow protection, and a frame element ( 22 ) is formed at the rear edge of the carrier plate and forms the rear-side portion ( 8 ) of the overflow protection, said frame element extending respectively over the entire length of the front edge and of the rear edge. The front-side and the rear-side portion of the overflow protection also extend in each case over a fraction of the two side edges, so that in each case a band ( 13 ) of a hydrophobic layer ( 12 ) is arranged only along a middle region of the two sides of the carrier plate ( 2 ). The portions arranged at the sides may advantageously serve for holding in the refrigerator, the shelf possessing a greater useful width in the middle region. Further carrier elements are not required. 
       FIG. 4  illustrates in cross-sectional views several embodiments of the transition region between a hydrophobic layer and a frame element by the example of the embodiment according to  FIGS. 1 and 2 . 
     In a first embodiment according to  FIG. 4A , the hydrophobic layer ( 12 ) runs from the first portion exactly as far as the lower edge of the front-side frame element ( 7 ) and rear-side frame element ( 8 ). In a second embodiment according to  FIG. 4B , the hydrophobic layer ( 12 ) runs from the first portion beneath the frame element and extends under the frame element as far as the end of the carrier plate. In a third embodiment according to  FIG. 4C , the hydrophobic layer ( 12 ) runs from the first portion as far as the lower edge of the frame element and is then arranged on the frame element. In this embodiment, the hydrophobic layer terminates at the end of the vertical edge of the frame element. 
     LIST OF REFERENCE SYMBOLS 
     
         
           1  Shelf 
           2  Carrier plate 
           5  Middle region 
           7  Front-side portion 
           8  Rear-side portion 
           9  Lateral portions 
           12  Hydrophobic layer 
           13  Band of the hydrophobic layer 
           14  Fastening element 
           22  Frame element