Abstract:
An extendible refrigerator shelf assembly includes a shelf and a support frame including gussets forming shelf stops to engage forward tabs laterally extending from the shelf. The support frame includes side supports having a sliding surface of different widths to retain and release the forward and rear tabs of the shelf. In an extended position, a front edge of the shelf may be lifted to release the front tabs, and the shelf may pulled slightly outward until the rear tabs reach a release position where they may be lifted through the side support ledges.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to shelves and, more particularly, to extendible shelves for use in refrigerators. 
     One type of extendible or “slide-out” refrigerator shelf assembly includes slide mechanisms and latch springs that engage a portion of a shelf when the shelf is in an extended position. The latch springs restrict movement of the shelf beyond a predetermined position and releasably hold the shelf in an extended position. See, for example, U.S. Pat. No. 5,340,209. 
     Removal of slide out refrigerator shelves, however, is problematic because the slide mechanisms for the shelves must support the shelf in a fully or partially extended position and thus must securely couple the shelf to shelf supports. Consequently, removal or separation of the shelf from the supports is intricate and often awkward. Some removable slide-out shelves require extension of the shelf substantially beyond a normal fully extended position to release the shelf from the shelf supports, which is further problematic when a space or clearance for opening of a refrigerator door is restricted. 
     Accordingly, it would be desirable to provide securely mounted and easily extendible slide-out shelves that are easily removed even when the opening of a refrigerator door is restricted. 
     BRIEF SUMMARY OF THE INVENTION 
     In an exemplary embodiment, a removable slide-out refrigerator shelf includes a shelf having laterally extending forward tabs and laterally extending rear tabs, and extended refrigerator shelf supports including gussets which act as shelf stops. The shelf slides upon ledges in the side supports, and the forward and rear tabs extend from the shelf below the ledge to couple the ledge to the shelf. The side support ledges include a forward portion having a width allowing the forward tab to be deliberately separated from the supports with ease when the shelf is fully extended by lifting a front edge of the shelf, and center and rear portions of greater width to secure the forward and rear tabs, respectively, of the shelf to the supports and prevent inadvertent separation of the shelf from the shelf supports during movement of the shelf between extended and retracted positions. 
     More specifically, the shelf is extended until the forward tabs contact the gusset stops. From this position the shelf may be lifted upward to elevate the forward tabs over the gusset stops and through the forward portions of the support ledges, thereby releasing the forward tabs. The rear tabs, however, remain engaged to the shelf supports via the rear portions of the support ledges having a width sufficient to prevent the rear tabs from being lifted through the support ledge rear portions. With slight outward extension of the shelf once the forward tabs are disengaged from the gusset stops, the rear tabs are positioned within the center portions of the support ledges having a width allowing the rear tabs to be lifted through the center portions of the support ledges to completely remove the shelf from the side supports. 
     The shelf rear tabs are positioned relative to the forward tabs so that the rear tabs are located near the support ledge center portions when the forward tab contacts the gusset stops and the shelf is in a fully extended position. Therefore, once the forward tabs are disengaged, a small additional clearance is required to extend the shelf until the rear tabs reach the support ledge center portions where they may be separated from the side supports. Therefore, a secure extendible refrigerator shelf is provided that is quickly and easily removed from shelf supports even when clearance is restricted. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front perspective view of an exemplary refrigerator including an exemplary slide out shelf assembly; 
     FIG. 2 is a perspective view of the exemplary slide-out shelf assembly shown in FIG. 1 in an extended position; 
     FIG. 3 is a top perspective view of the support frame shown in FIG. 2; 
     FIG. 4 is a top plan view of the shelf rim shown in FIG. 2; 
     FIG. 5 is a longitudinal end view of the shelf rim shown in FIG. 4; 
     FIG. 6 is a partial rear view of the rim shown in FIG. 5; 
     FIG. 7 is a top perspective view partially broken away of the shelf assembly shown in FIG. 2 in an extended position; and 
     FIG. 8 is a magnified view of a portion of FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is a perspective view of an exemplary large top mount refrigerator  10  including an outer cabinet  12  including a fresh food compartment  14  and a freezer compartment (not shown) separated by an internal wall  16 . A fresh food door  18  and a freezer door  20  provide access to fresh food compartment  14  and to the freezer compartment, respectively. Fresh food door  18  typically includes a number of shelves  22  for storage of foodstuffs. A number of storage drawers  24  are provided in the lower portion of fresh food compartment  14 , and a plurality of vertically adjustable shelf assemblies  26 ,  28  and  30  on two tracks  32  are provided in the upper portion of fresh food compartment  14 . Shelf assembly  28  is a slide-out shelf assembly in a retracted position, and is selectively positionable from a retracted position (shown in FIG. 1) to an extended position (described below) to allow more convenient access to items placed upon shelf assembly  28 . 
     While described and illustrated in the exemplary context of a middle shelf of a top mount refrigerator, it is contemplated that shelf assembly  28  could be used in other applications, including but not limited to other types of refrigerators, such as side-by-side refrigerators, as well as slide-out shelves, drawers, and bin assemblies for use in a wide variety of products of general application. As the benefits of the present invention accrue to uses well beyond use as a refrigerator shelf, the present invention is not limited to specific application in a refrigerator, such as, for example, refrigerator  10 . 
     FIG. 2 is a perspective view of shelf assembly  28  in an extended position. Shelf assembly  28  is mounted on rails or tracks  32  attached to a rear wall  34  of fresh food compartment  14  (shown in FIG.  1 ). Shelf assembly  28  includes a support frame  36  and a glass encapsulated shelf  38 . Frame  36  includes two side supports  40  and  42 , a front cross rod  44  and a rear cross rod  46 . Each of side supports  40  and  42  include an inwardly projecting flange ledge  48  and  50 , respectively, upon which shelf  38  slides. Shelf  38  includes a rectilinear transparent plate  52  held within grooves  54  of a surrounding rim  56  fabricated from a suitable plastic material such as, for example, acrylonitrile-butadiene-styrene (ABS). An anti-spill guard  58  is positioned across the rear of rim  56  and is integral with rim  56 . In an alternative embodiment, guard  58  is a separate piece from rim  56 , including, but not limited to, a clip on piece. A front edge  60  of rim  56  is curved downwardly to form a handle  62  which a user may grasp to move shelf  38  between the extended position and the retracted position (shown in FIG. 1) wherein anti-spill guard  58  is positioned substantially adjacent rear wall  34 . 
     FIG. 3 is a top perspective view of support frame  36 . Side supports  40  and  42  include hooks  70  and projections  72  for engagement with vertical tracks  32  (shown in FIG. 2) to hold shelf assembly  28  (shown in FIG. 2) at a selected elevation. Each side support  40 ,  42  further includes a horizontally inwardly projecting doubly stepped upper flange or ledge  74  forming a surface  76  upon which shelf  38  (shown in FIG. 2) may slide. An inner surface  78  of supports  40 ,  42  is substantially perpendicular to ledges  74 , and shelf  38  is retained to side supports  40 ,  42  partially above and partially below ledges  74  and between inner surfaces  78  as described further below. 
     Each ledge  74  includes a rear portion  80  having a first width, a center portion  82  having a second width smaller than the first width, and a forward portion  84  having a third width smaller than the second width. Gussets  86  extend laterally inward from side frames  40  and  42  and include integral tabs  88  extending upwardly from gussets  86 . Cross rods  44 ,  46  rigidly connect side supports  40  and  42 , and cross rod  44  is bent upwardly so that it is hidden by shelf  38  in the retracted position (shown in FIG.  1 ). 
     FIG. 4 is a top plan view of shelf rim  56  including front edge  60 , a rear edge  100 , and two side edges  102  forming an enclosure  104  to contain transparent plate  52  (shown in FIG.  2 ). Front edge  60  includes rounded handle  62 , and rear edge  100  includes anti-spill guard  58 . In one embodiment, rim  56  is substantially symmetrical about a longitudinal axis  106 . 
     FIG. 5 is a longitudinal end view of shelf rim  56  including three lateral projections, namely, a rear tab  110 , a centering lug  112  and a forward tab  114  extending from side edge  102  below groove  54  for receiving transparent plate  52  (shown in FIG.  2 ). Forward tab  114  extends laterally outward, i.e., away from shelf longitudinal axis  106  (shown in FIG. 4) from a lower portion  115  of side edge  102  for a first distance and extends slightly below a bottom  116  of side edge  102 . Centering lug  112  includes sloped sides  118  to facilitate smooth movement of shelf  38  (shown in FIG. 2) between extended and retracted positions and provides support to front tabs  114 . Sloped sides  118  prevent jamming of shelf  38  in side supports  40 ,  42  (shown in FIGS. 2 and 3) and gently direct shelf  38  into a proper centered position relative to side supports  40 ,  42  as shelf  38  is moved relative to support frame  36  (shown in FIGS.  2  and  3 ). 
     Rear tab  110  extends laterally outward i.e., away from shelf longitudinal axis  106  (shown in FIG. 4) from side edge lower portion  115  for a second distance less than the first distance for which forward tab  114  extends, and rear tab extends slightly above bottom  116  of side edge  102  adjacent rear edge  100 . Anti-spill guard  58  extends obliquely from a top surface  120  of rim  56 , and rounded front edge  60  extends downward from rim top surface  120 . A stop  122  depends downwardly from groove  54  below side edge bottom  116 . When shelf  38  (shown in FIG. 2) is in a fully retracted position, stop  122  contacts support frame cross rod  44  (shown in FIG.  3 ). 
     FIG. 6 is a partial rear view of rim  56  illustrating side edge lower portions  115  extending downwardly from groove  54  that retains transparent plate  52  (shown in FIG.  2 ). Side edge lower portion  115  is inwardly spaced from upper portions of side edges  102  to form a sliding surface that rests upon surfaces  76  (shown in FIG. 3) of side support ledges  74  (shown in FIG. 3) when shelf  38  (shown in FIG. 2) is installed in support frame  36  (shown in FIGS.  2  and  3 ). Forward tabs  114  extend outwardly from side edge lower portions  115  a greater distance than centering lugs  112  and rear tabs  114 . Anti spill guard  58  laterally extends above rim top surface  120  substantially the entire width of rim  56 , and includes flared sides  132  to prevent jamming of anti-spill guard  58  when shelf  38  (shown in FIG. 2) is installed onto support frame  36  (shown in FIGS.  2  and  3 ). 
     FIG. 7 is a top perspective view of shelf assembly  28  in the extended position with the left side edge  102  broken away, and FIG. 8 is a magnified view of a portion of FIG. 7 illustrating the release of shelf forward tab  114  from side support  40 . When shelf assembly  28  is extended, forward tab  114  contacts gusset tab  88  and prevents further outward movement or extension of shelf  38 . In the fully extended position, rear tabs  110  are positioned below side support ledge rear portion  80  and near a forward end  140  of side support ledge rear portion  80  so that shelf  38  is securely retained to side supports  40 ,  42 . The proximity of rear tab  110  and side support ledge center portion  82  allows full release of shelf  38  with minimal additional extension of shelf assembly  28 . 
     By lifting rim front edge  60  when shelf assembly  28  is in the fully extended position, forward tabs  114  of rim side edge lower portion  115  may be elevated over gusset tab  88  and forward tabs  114  released from side supports  40 ,  42  between forward ledge portions  84 . By pulling shelf  38  longitudinally away from side supports  40 ,  42 , shelf  38  quickly reaches a release position (not shown) in which rear tabs  110  are positioned forward of side support ledge rear portions  80  and within side support ledge center portions  82  that are dimensioned to provide a lateral clearance for rear tabs  110 . Shelf  38  may therefore be released by lifting rear tabs  110  upward and through side support ledge center portions  82 . 
     In one embodiment, a release position is provided that requires about two inches additional extension beyond the normal fully extended position, and more conveniently of about one inch, which is appreciably less than that required by known extendible shelves for release. Once the release position is obtained, shelf  38  may be fully removed from side supports  40 ,  42  by lifting shelf  38  upward and away from side supports  40 ,  42 . 
     Return or installation of shelf  38  is accomplished by inserting rear tabs  110  in side support ledge center portions  82 , elevating forward tabs  114  over gusset tabs  88  and sliding shelf  38  backward over side supports  40 ,  42  until rim stops  122  (shown in FIG. 5) contact gusset tabs  88  and shelf  38  is in a fully retracted position. Centering lugs  112  (shown in FIG. 5) guide shelf  38  and maintain shelf  38  properly centered between side support inner surfaces  78  (shown in FIG. 3) as shelf  38  is extended and retracted in use. Installation and removal of shelf  38  may be accomplished with one hand. 
     Thus, an extendible shelf assembly  28  is provided that securely couples shelf  38  to side supports  40 ,  42  while allowing a user to remove and reinstall shelf  38  from side supports  40 ,  42  quickly and easily as desired such as, for example, cleaning of shelf  38 . The diminished extension required to place shelf  38  in the release position relative to known extendible shelf assemblies allows shelf  38  to be removed even in restricted access conditions. 
     While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.