Abstract:
A system for limiting outward movement of a slide-out shelf includes a plurality of side supports configured to support the shelf, a positive stop extending along each of the side supports, and a plurality of support members configured to rigidly connect the side supports and contact at least a portion of the shelf thereby blocking forward movement of the shelf.

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. However, consumer confidence may decrease if the shelf becomes unbalanced. 
   BRIEF SUMMARY OF THE INVENTION 
   In one aspect, a system for limiting outward movement of a slide-out shelf includes a plurality of side supports configured to support the shelf, a positive stop extending along each of the side supports, and a plurality of support members configured to rigidly connect the side supports and contact at least a portion of the shelf thereby blocking forward movement of the shelf. 
   In another aspect, a method for assembling a shelf assembly is provided. The method includes providing a shelf that includes a forward edge, at least one forward tab and at least one rear tab, providing at least one side support including at least one side support clearance, at least one gusset and at least one rear positive stop, and slidably coupling the shelf to the side supports. 
   In another aspect, a slide-out refrigerator shelf assembly includes a shelf including a first side, a forward tab laterally extending a first distance from the first side, and a rear tab laterally extending a second distance from the first side, the second distance less than the first distance. The shelf assembly also includes a first shelf side support comprising a laterally projecting ledge for sliding engagement with the shelf first side and the projecting ledge includes a rear portion having a first width sufficient to retain the rear tab, a forward portion having a second width less than the first width and providing a clearance for the rear tab and further providing a clearance for the forward tab, the clearance having a third width providing a clearance for the forward tab. 

   
     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 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 side view of the support frame shown in  FIG. 2 ; 
       FIG. 5  is a side view of the shelf rim shown in  FIG. 1 ; 
       FIG. 6  is a partial magnified bottom perspective view of the middle portion of the shelf shown in  FIG. 5 ; 
       FIG. 7  is a partial magnified bottom perspective view of the rear portion of the shelf shown in  FIG. 6 ; 
       FIG. 8  is a bottom perspective view of the shelf assembly shown in  FIG. 2 ; and 
       FIG. 9  is a partial magnified perspective view of the forward portion of  FIG. 8 . 
   

   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  16  separated by an internal wall  18 . A fresh food door  20  and a freezer door  22  provide access to fresh food compartment  14  and to the freezer compartment  16 , respectively. Fresh food door  20  typically includes a number of shelves  24  for storage of foodstuffs. A number of storage drawers  26  are provided in the lower portion of fresh food compartment  14 , and a plurality of vertically adjustable shelf assemblies  28  and  30  on two rails  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 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 slide-out shelf assembly  28  in an extended position. Shelf assembly  28  is mounted on rails  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 , a forward support member  44  and a rear support member  46 . Support members  44 ,  46  rigidly connect side supports  40 . Each side support  40  includes a horizontally inwardly projecting doubly stepped flange or ledge  48 , 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) or high impact polystyrene (HIPS). An anti-spill guard  58  is positioned across the rear of rim  56  and is integral with rim  56 . In an alternative embodiment, shelf  38  includes rectilinear transparent plate  52  held within grooves  54  of surrounding rim  56  by an ultrasound weld. A forward edge of rim  56  curves downwardly forming a handle  60  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 . In one embodiment, rim  56  is substantially symmetrical about a longitudinal axis  62 . 
     FIG. 3  is a top perspective view and  FIG. 4  is a side view of support frame  36 . Each side support  40  includes a hook  70 , a projection  72 , and a rear stop  74  for engagement with vertical rails  32  (shown in  FIG. 2 ) to hold shelf assembly  28  (shown in  FIG. 2 ) at a selected elevation. In case of improper shelf installation, rear stops  74  facilitate preventing dislodgment of support frame  36  from rails  32 . 
   Each ledge  48  includes a surface  76  upon which shelf  38  (shown in  FIG. 2 ) may slide. An inner surface  78  of supports  40  is substantially perpendicular to ledges  48 , and shelf  38  is retained to side supports  40  partially above and partially below ledges  48  and between inner surfaces  78  as described further below. Each ledge  48  further includes a rear portion  80  having a first width, a forward portion  82  having a second width smaller than the first width, and a track clearance  84  having a third width smaller than the second width. A gusset  86  extends laterally inward from the forward portion  82  of each side support  40  and includes an integral tab  88  extending upwardly from gusset  86 . Tabs  88  are substantially adjacent to support member  44 , and together facilitate preventing shelf  38  from extending beyond a fully a fully extended position. 
     FIG. 5  is a side view of shelf rim  56  including two lateral projections, namely, a forward stop tab  110  and a rear tab  112  extending from a side edge  102  below groove  54 .  FIGS. 6 and 7  provide magnified bottom perspective views of both forward stop tab  110  and rear tab  112 . Forward stop tab  110  extends laterally outward, i.e., away from shelf longitudinal axis  106  (shown in  FIG. 3 ) from a lower portion  114  of side edge  102  for a first distance. Lower portion  114  is inwardly spaced from upper edges of  102  to form a sliding surface that rest upon surfaces  76  (shown in  FIG. 3 ) of side support  40  (shown in  FIG. 3 ) when shelf  38  (shown if  FIG. 2 ) is installed in support frame  36  (shown in  FIG. 2 ). Forward stop tab  110  includes sloped sides  116  to facilitate smooth movement of shelf  38  between extended and retracted positions and provides support to forward stop tabs  110 . Sloped sides  116  facilitate the prevention of jamming shelf  38  in side supports  40  and gently direct shelf  38  into an advantageous centered position relative to side supports  40  as shelf  38  is moved relative to support frame  36 . 
   Rear tab  112  extends laterally outward away from shelf longitudinal axis  106  (shown in  FIG. 3 ) from side edge  102  for a second distance less than the first distance for which forward stop tab  110  extends. In one embodiment, rear tab  112  extends laterally outward a distance equal to distance for which forward stop tab  110  extends. Additionally, rear tab  112  extends parallel with axis  106  and rear tab  112  includes a forward lip  120  and rear portion  122 . Anti-spill guard  58  extends obliquely from a top surface  124  of rim  56 , and rounded forward edge  60  extends downward from rim top surface  124 . Anti spill guard  58  laterally extends above rim top surface  124  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 ). 
     FIG. 8  is a bottom perspective view of shelf assembly  28  in the extended position with left side edge  102  broken away, and  FIG. 9  is a magnified perspective view of a portion of  FIG. 8  illustrating the release of shelf forward stop tab  110  from side support  40 . When shelf  38  is extended, forward stop tab  110  contacts gusset tab  88  (shown in  FIG. 4 ) and support member  44  and prevents further outward movement or extension of shelf  38 , and rear tabs  112  are positioned below side support ledge rear portion  80  so that shelf  38  is securely retained to side supports  40 . The engagement of the forward stop tab  110  to gusset tab  88  and support member  44 , respectively, communicate to the users that the shelf is fully extended. Additionally, the proximity of rear tab  112  to side support ledge forward portion  82  allows full release of shelf  38  only after following the below-described steps for removal. 
   Full release of shelf  38  is facilitated by pulling rim forward edge  60  of shelf  38  and positioning forward stop tabs  110  just below track clearances  84 . Track clearances  84  are located adjacent on the front side of support member  44  and above gusset  88 . Lifting rim forward edge  60  upwards when forward stop tabs  110  are located at track clearance  84  releases the forward portion of shelf  38  from side supports  40 . By further pulling shelf  38  longitudinally away from side supports  40 , rear tabs  112  reach a release position (not shown) in which rear tabs  112  are positioned forward of side support ledge rear portions  80  and within side support ledge forward portions  82  that are dimensioned to provide a lateral clearance for rear tabs  112 . Shelf  38  may therefore be released by lifting rear tabs  112  upward and through side support ledge forward portions  82 . 
   In one embodiment, a release position is provided wherein the extension is reduced by 2.54 centimeters of the normal fully extended position, and conveniently assures the user that full extension is achieved and stable. Once the release position is obtained, shelf  38  may be fully removed from side supports  40  by lifting shelf  38  upward and away from side supports  40 . In another embodiment, the extension is reduced by other than 2.54 centimeters. 
   Return or installation of shelf  38  is accomplished by inserting rear tabs  112  in side support ledge forward portions  82 , inserting forward stop tabs  110  into track clearances  84  and sliding shelf  38  backward over side supports  40  until shelf  38  is in a fully retracted position. 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  while allowing a user to remove and reinstall shelf  38  from side supports  40  quickly and easily as desired such as, for example, cleaning of shelf  38 . The deliberate extension required to place shelf  38  in the fully extended position relative to the release position allows shelf  38  to be extended back and forth with increased consumer confidence. Accordingly, a reliable and cost efficient shelf is provided. The shelf is a securely mountable and easily extendible slide-out shelf that is easily removed. 
   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.