Patent Publication Number: US-8534783-B2

Title: Shelf assembly with a single-piece frame particularly suited for use in a refrigeration appliance

Description:
FIELD OF THE INVENTION 
     The present subject matter relates generally to a shelf configuration, and more particularly to a spill-proof refrigerator shelf. 
     BACKGROUND OF THE INVENTION 
     A refrigerator typically includes a number of shelves for the storage of food and beverage containers of many shapes and sizes. As the containers are retrieved, returned and/or rearranged on the shelves, occasional leaks and spilling of food and liquid may occur. Cleaning up after a spill on a crowded refrigerator shelf can be difficult, especially when spilled liquid leaks onto lower shelves. 
     To contain liquid spills on a refrigerator shelf, it is known to use “picture frame” shelves that include edges wrapped around, attached, or otherwise fitted to a glass plate to form a dam around the edges of the plate for containing spilled liquid. Reference is made, for example to U.S. Pat. No. 5,677,030, which describes a continuous edge trim that wraps around the peripheral edge of a glass shelf and extends above the glass to form a spill-proof dam. The trim piece has a substantially “F” shaped cross-sectional profile, with the glass sliding into the “U” chamber defined by the upper and lower arms. U.S. Pat. Nos. 5,429,433; 5,524,981; and 5,403,084 describe refrigerator shelves having a rim directly molded around the entire perimeter edge of the shelf member. Frame assemblies are also known that include separate upper and lower frame members, with the glass pane sandwiched between the frame members. 
     The conventional picture frame shelf assemblies have certain disadvantages from a production and/or cost perspective, or in terms of performance. For example, the insert molding (glass encapsulation) processes may depend on shrinkage of the plastic used to fabricate the frame, which requires the edges of the glass plate to be notched for the frame to properly seal the glass. The frames formed from separate frame members require multiple tools to form the frame members. 
     Accordingly, it would be desirable to provide a spill-proof shelf assembly that is reliable, is not dependent on variances between the glass shelf dimensions and/or shrinkage of the frame members, and is commercially feasible to produce. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention. 
     In an exemplary embodiment, a shelf assembly is provided that is particularly suited for use in a refrigeration appliance, such as a refrigerator, freezer, and the like. The shelf assembly includes a pane having perimeter edges. The pane is encased in a single-piece frame structure fitted around the perimeter of the pane. The frame structure has a unitary upper frame member extending inwardly from the pane edges along a top surface of the pane. The frame structure includes a plurality of lower frame members, with a respective lower frame member connected to the upper frame member along each edge of the pane. The lower frame members are pivotally configured with the upper frame member and are folded under the upper frame member so as to extend inwardly along a bottom surface of the pane. A suitable attachment mechanism is configured between the lower frame members and the upper frame member outward of the pane edges. Thus, the pane is essentially clamped between the upper frame member and the lower frame members along the edges of the pane. 
     In another exemplary embodiment, a pull-out refrigeration appliance shelf assembly includes a pane having a perimeter defined by side edges, a front edge, and a back edge. A single-piece frame structure is fitted around the perimeter of the pane and includes a unitary upper frame member in which the pane is seated. The upper frame member has a flange portion that extends inwardly from the pane edges along a top surface of the pane. The pane is positively located and seated in the upper frame member by means of shoulders that extend from an underside of the upper frame member and engage against the edges of the pane. A respective lower frame member is pivotally connected to the upper frame member with a living hinge along each edge of the pane. The lower frame members are folded under the upper frame member around the pane edges and extend inwardly along a bottom surface of the pane. The lower frame members are fastened to the upper frame member outward of the pane edges. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
         FIG. 1  is a perspective view of a refrigeration appliance, in particular a refrigerator, incorporating one or more shelf assemblies in accordance with aspects of the invention; 
         FIG. 2  is a perspective view of a shelf assembly; 
         FIG. 3  is a perspective and partial cut-away view of the shelf assembly of  FIG. 2 ; 
         FIG. 4  is a perspective view of an embodiment of the upper and lower frame members of the shelf assembly; 
         FIG. 5  is a cross-sectional view of an embodiment of an attachment mechanism between the upper and lower frame members; 
         FIG. 6  is a cross-sectional and partial operational view of a particular embodiment of a frame structure; 
         FIG. 7  is a cross-sectional and partial operational view of another embodiment of a frame structure; and 
         FIG. 8  is a cross-sectional and partial operational view of an embodiment of a front edge of a frame structure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
       FIG. 1  is a perspective view of an exemplary refrigeration appliance  10  depicted as a refrigerator in which shelf assemblies in accordance with aspects of the present invention may be utilized. It should be appreciated that the appliance of  FIG. 1  is for illustrative purposes only and that the present invention is not limited to any particular type, style, or configuration of refrigeration appliance, and that such appliance may include any manner of refrigerator, freezer, refrigerator/freezer combination, and so forth. 
     Referring to  FIG. 1 , the refrigerator  10  includes a fresh food storage compartment  12  and a freezer storage compartment  14 , with the compartments arranged side-by-side and contained within an outer case  16  and inner liners  18  and  20  generally molded from a suitable plastic material. In smaller refrigerators  10 , a single liner is formed and a mullion spans between opposite sides of the liner to divide it into a freezer storage compartment and a fresh food storage compartment. The outer case  16  is normally formed by folding a sheet of a suitable material, such as pre-painted steel, into an inverted U-shape to form top and side walls of the outer case  16 . A bottom wall of the outer case  16  normally is formed separately and attached to the case side walls and to a bottom frame that provides support for refrigerator  10 . 
     A breaker strip  22  extends between a case front flange and outer front edges of inner liners  18  and  20 . The breaker strip  22  is formed from a suitable resilient material, such as an extruded acrylo-butadiene-styrene based material (commonly referred to as ABS). The insulation in the space between inner liners  18  and  20  is covered by another strip of suitable resilient material, which also commonly is referred to as a mullion  24  and may be formed of an extruded ABS material. Breaker strip  22  and mullion  24  form a front face, and extend completely around inner peripheral edges of the outer case  16  and vertically between inner liners  18  and  20 . 
     Shelves  100 , slide-out drawers  26 , and a storage bin  28  are normally provided in fresh food storage compartment  12  to support items being stored therein. The shelves  100  are described in greater detail below. In addition, at least one shelf  30  and at least one wire basket  32  are also provided in freezer storage compartment  14 . 
     The refrigerator features are controlled by a controller  34  according to user preference via manipulation of a control interface  36  mounted in an upper region of fresh food storage compartment  12  and coupled to the controller  34 . As used herein, the term “controller” is not limited to just those integrated circuits referred to in the art as microprocessor, but broadly refers to computers, processors, microcontrollers, microcomputers, programmable logic controllers, application specific integrated circuits, and other programmable circuits, and these terms are used interchangeably herein. The controller  34  may also be an electromechanical device. 
     A freezer door  38  and a fresh food door  40  close access openings to freezer storage compartment  14  and fresh food storage compartment  12 . Each door  38 ,  40  is mounted by a top hinge  42  and a bottom hinge (not shown) to rotate about its outer vertical edge between an open position, as shown in  FIG. 1 , and a closed position. The freezer door  38  may include a plurality of storage shelves  44  and a sealing gasket  46 , and fresh food door  40  also includes a plurality of storage shelves  48  and a sealing gasket  50 . 
     The freezer storage compartment  14  may include an automatic ice maker  52  and a dispenser  54 , provided in the freezer door  38  such that ice and/or chilled water can be dispensed without opening the freezer door  38 , as is well known in the art. 
     As with known refrigerators, the refrigerator  10  also includes a machinery compartment (not shown) that at least partially contains components for executing a known vapor compression cycle for cooling air. The components include a compressor, a condenser, an expansion device, and an evaporator connected in series and charged with a refrigerant. The evaporator is a type of heat exchanger which transfers heat from air passing over the evaporator to the refrigerant flowing through the evaporator, thereby causing the refrigerant to vaporize. The cooled air is used to refrigerate one or more refrigerator or freezer compartments via fans. Collectively, the vapor compression cycle components in a refrigeration circuit, associated fans, and associated compartments are conventionally referred to as a sealed system. The construction and operation of the sealed system are well known to those skilled in the art. 
       FIG. 2  depicts an embodiment of a shelf assembly  100  that incorporates aspects of the invention and may be used in the refrigerator  10  depicted in  FIG. 1 , or in any other type of refrigeration appliance. Although the shelf assembly  100  is particularly suited for use in a refrigeration appliance, it should be appreciated that the shelf assembly  100  is not limited to such use and may have utility in any type of storage device or compartment wherein a spill-proof shelf having the attributes of the present invention is desired. The shelf assembly  100  includes a shelf pane  102 , which is typically formed from glass or any other suitable material, such as a clear plastic material. The pane  102  has edges  104  that define a perimeter of the pane  102 . The pane  102  includes a top surface  110  and a bottom surface  112  ( FIG. 6 ). 
     The shelf assembly  100  includes a single-piece frame structure  114  that is fitted around the perimeter of the shelf pane  102 . The frame structure  114  is “single-piece” in that it does not comprise multiple components that are assembled or separately fitted together around the pane  102 , but is a single unitary member that encases the edges  104  of the pane  102 , as described in greater detail below. 
     In a particular embodiment, the frame structure  114  is molded from a plastic material having characteristics suitable for use in the environment of the shelf assembly  100 . For example, the frame structure  114  may be fabricated from a talc-filled polypropylene, acrylonitrile-butadine-styrene (ABS), or high-impact polystyrene (HIPS). Other suitable materials may also be used. 
     Referring to  FIGS. 2 through 5  in particular, the single-piece frame structure  114  includes a unitary upper frame member  116  that extends inwardly from edges  104  along the top surface  110  of the pane  102  and outwardly beyond the edges  104 . In particular, the upper frame member  116  may include a flange portion  120  that extends onto the top surface  110 . The flange  120  may terminate at an end that creates a dam  122  to fluids that may be spilled onto the top surface  110 . Other portions of the upper frame member  116  may extend outwardly beyond the edges  104  of the pane  102 , as described in greater detail below. 
     The frame structure  114  includes a plurality of lower frame members  126 , with at least one of the lower frame members  126  connected to a respective side of the upper frame member  116  along one of the pane edges  104 . The lower frame members  126  are pivotally configured with the upper frame member  116  at a hinge line  130  and are folded at the hinge line  130  so as to extend under and inwardly along a bottom surface  112  of the pane  102 . In the illustrated embodiment, the lower frame members  126  include a flange portion  128  that engages against the bottom surface  112  of the pane  102 , as particularly illustrated in  FIGS. 6 and 7 . Other portions of the lower frame member  126  extend outwardly beyond the edges  104  of the pane  102 . 
     The single-piece frame structure  114  may be formed from separate frame members  116 ,  126  that are subsequently joined along the hinge line  130 . For example, a plurality of lower frame member components may be ultra-sonically welded to the upper frame member  116  along respective hinge lines  130 . 
     The frame members  116 ,  126  may include any manner of additional structure formed therewith or attached thereto. For example, attachment devices can be provided to attach track brackets for a cant track shelf support. Also, the frame members may be configured for receipt of any manner of component associated with a slide system for sliding the shelf assembly  100  into or out of the refrigerator compartment. 
     A suitable attachment mechanism  138  is configured between the lower frame members  126  and the upper frame member  116  along each edge  104  of the pane  102 . The attachment mechanism  138  is configured between the portions of the frame members  116 ,  126  that extend outward beyond the edges  104 . In a particular embodiment illustrated in the figures, the attachment mechanism  138  is defined by a male member configured on one of the frame members that engages with a female member configured on the other respective frame member. For example, referring to  FIGS. 4 and 5  in particular, the male component of the attachment mechanism  138  is defined by a tab  144 . The female component is defined by a slot  146  defined in the lower frame member  126 . When the lower frame member  126  is folded under the pane  102 , the tabs  144  engage through the slots  146 , as particularly illustrated in FIGS.  4  and  5 . The tabs  144  are subsequently capped, for example in a heat-stake process wherein a cap  148  is permanently formed on the portion of the tabs  144  that extend through the slots  146 . Alternatively, any other suitable means may be utilized to ensure that the tabs  144  do not pull out from the slots  146 . In the illustrated embodiment, a plurality of the tabs  144  and slots  146  are configured along each side of the frame structure  114 . 
     In a particular embodiment illustrated in the figures, the hinge line  130  is defined by a living hinge  132  that connects the lower frame members  126  with the upper frame member  116 . The living hinge  132  may be defined by a thinned or weakened area of the plastic material along the hinge line  132 . In an alternate embodiment, the living hinge  132  may be defined by a flexible strip of material that is co-molded with the frame members  116 ,  126  along the hinge lines  130 , or otherwise attached to the frame members. 
     Desirably, a gasket material  134  is sandwiched between the top surface  110  of the pane  102  and the flange  120  of the upper frame member  116 . In the embodiment of  FIG. 3 , the gasket material  134  may be a strip of sealing material that is applied on the top surface  110  prior to installation of the frame structure  114  around the pane  102 . In an alternative embodiment illustrated in  FIG. 4 , the gasket material  134  is a strip of material that is a component of the upper frame member  116 . For example, the gasket material  134  may be co-molded with the flange  120 . In an alternative embodiment, the gasket material  134  may be pre-applied to the pane  102 , for example in a hot-stamping process. The gasket material  134  may be a bead of material, such as silicon, that is applied to the pane  102  or upper frame member  116 . It should also be appreciated that the invention is not limited to any particular type of gasket material  134 . TPE (Thermoplastic Elastomer) and TPO (Thermoplastic Polyolefin) are suitable materials, as well as a number of other moldable resilient materials. Compression or performance of the gasket material  134  produces the spill-proof characteristic of the shelf assembly  100 . “Spill-proof” is generally recognized in the art as the ability of the shelf to retain twelve oz. of fluid for at least twenty-four hours. Lesser performance is generally referred to as “spill-resistant.” 
     In alternative embodiments, the gasket material  134  may be replaced by, or augmented with, a hydrophobic coating applied around the perimeter of the pane  102 . 
     As particularly seen in  FIGS. 4 through 8 , one or more reinforcing ribs  136  may extend between the upper frame member  116  and the lower frame member  126  in the portion of the frame members that is outward of the pane edges  104 . These reinforcing ribs  136  provide a desired degree of structural integrity to the frame structure  114  to ensure that the shelf assembly  100  can carry the designed load and be supported by brackets or other support structure within the appliance  10 . 
     In order to positively seat the pane  102  within the frame structure  114  during construction of the shelf assembly  100 , positioning shoulders  150  may be provided around the perimeter of the frame structure  114 . In the illustrated embodiment, the shoulders  150  are defined by the tabs  144  that also function as components of the attachment mechanism  138 . For example, as seen in  FIGS. 3 and 6  through  8 , the edges  104  of the pane  102  engage against the tabs  144  that extend downwardly from the upper frame member  116 . Thus, to assembly the shelf  100 , the frame structure  114  is placed on a support surface with the upper frame member  116  facing down and the lower frame members  126  folded outward. The shelf pane  102  is then placed into the upper frame member  116  so as to be seated within the tabs  144  and engaged against the shoulders  150 . The lower frame members  126  are then folded over onto the back surface  112  of the pane  102  and permanently attached to the upper frame member  116  with any manner of suitable attachment mechanism  138  as described above. 
     In a unique embodiment, the shelf assembly  100  is configured as a pull-out shelf that can be slid into and out of the refrigerator  10  or other appliance. For this purpose, a curved pull-out handle  152  may be configured at the front edge of the pane  102  by the frame structure  114 . For example, referring to  FIGS. 3 and 8 , the pull-out handle  152  may be formed by a curved extension  154  of the upper frame member  116  that mates with a curved extension portion  156  of the lower frame member  126 . The living hinge  132  may be defined between the curved extensions  154 ,  156 . 
     The frame structure  114  may further define a slide surface to facilitate movement of the shelf assembly  100  into and out of the refrigerator  10 , for example along ledges defined in the liners  18 ,  20  ( FIG. 1 ). In the illustrated embodiment, a slide surface  158  is defined by the frame structure  114  forward of an offset  160  defined along the sides of the shelf assembly  100 , as particularly illustrated in  FIGS. 2 and 3 . The slide surface  158  is defined on the portion of the lower frame member  126  that extends outward beyond the pane edges  104  forward of the offset  160 . A stop  162  is defined by the frame structure  114  along the back edge of the shelf assembly  100 . The stop  162  engages against the support structure in the refrigerator  10  to prevent inadvertent pulling of the shelf  100  completely out of the refrigerator  10 . The offset  160  defines a portion of reduced width dimensions along the sides of the shelf assembly  100  rearward of the offset  160  for vertical air flow along the shelf assembly  100 . Similarly, a cutout or reduced width section  164  is defined along the back edge of the frame structure  114  between respective lower frame members  126  configured on opposite sides of the cutout section  164 . The cutout section  164  also defines an airflow passage along the back edges of the shelf assembly  100 . The airflow passages along the sides and back edges of the shelf assembly  100  ensure even cooling airflow around the shelves when the shelves are placed within the refrigerator  10 . 
     It should be appreciated that the frame structure  114  may have various configurations within the scope and spirit of the invention. For example, in the embodiment illustrated in  FIG. 6 , the side wall  124  of the frame structure  114  is defined as a component of the lower frame member  126 , with the living hinge  132  defined between the side wall  124  and the upper frame member  116 . In the embodiment illustrated in  FIG. 7 , the side wall  124  is configured as a component of the upper frame member  116 , with the living hinge  132  configured between the side wall  124  and the lower frame member  126 . 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.