the add - on , self - facing shelf trays of this invention can come in a variety of configurations including ( 1 ) a gravity feed arrangement , ( 2 ) a base mount version where a pusher track with a suitable biasing means is provided as the base of the unit and ( 3 ) a side mount version where a suitable biasing means is supported from a side wall of the unit . in each version the biasing means urges the stored product toward the front of the tray . in a preferred embodiment , the tray includes a front track 10 , a rear track 12 , an interior or center divider 14 , and end dividers 16 and 18 . looking at the front track 10 in fig1 - 3 , it has a planar , generally vertical panel or front panel 20 which will extend vertically when in use . the front panel 20 has outer and inner surfaces . a generally horizontal panel or support panel 26 extends from the lower end of the inner surface of the front panel 20 and will project rearwardly when in use . the front and support panels 20 , 26 are elongated and linear along their respective extensions . with reference to fig3 the upper end of the front panel 20 includes a slot 28 . that is , a horizontal web 30 extends from the inner surface of the front panel 20 . in the illustrated embodiment , the web 30 is generally parallel to the support panel 26 and is at a right angle to inner surface of the front panel 20 , but of limited rearward extension as compared to the support panel 26 . a vertical leg 32 extends upwardly from the web 30 and terminates in a forwardly turned nose 34 above the web 30 . similarly , the upper end of the front panel 20 terminates in a rearwardly turned nose 36 that is opposed to but spaced from the nose 34 . that structure defines slot 28 which extends the length of the front track 10 but has a restricted entrance to its interior . the purpose for this slot 28 will be explained hereinafter . still referring to fig3 the upper end of the front panel 20 includes a lip 37 that extends rearwardly of and partially below the web 30 and extends along the length of the front track 10 . this lip 37 is spaced from the inner surface of the front panel 20 , and together with the web 30 and the inner surface of the front panel 20 , defines a downwardly facing recess 38 . the use of this recess 38 also will be explained hereinafter . still referring to fig3 a holding rib 40 is provided on the support panel 26 . the holding rib 40 is spaced rearwardly of the recess 38 and extends upwardly from the support panel 26 . completing the structure of the front track 10 is an elongated slot 44 recessed downwardly from the upper surface of the support panel 26 and extending the length of the front track 10 and parallel to front panel 20 . two upward projecting ribs 46 and 48 are provided , one on either side of the slot 44 . these are of a different material than the front track 10 itself . the front track 10 is extruded and made of a conventional polyvinyl chloride except for the ribs 46 and 48 which are made of a softer polyvinylchloride and are coextruded with the remainder of the front track 10 . the rear track 12 is identical to the front track 10 . therefore , the rear track 12 is not separately illustrated except as it is part of the overall assembly . where reference is necessary to the rear track 12 , portions corresponding to the already - described front track 10 are identified by the same number but with the addition of the letter “ r ” ( see for example , fig2 ). referring again to fig4 an insert 50 is carried on the front track . the insert 50 helps retain the product behind the front track 10 but is made of a clear acrylic so that it does not interfere with viewing the product . the insert 50 is basically a planar , elongated strip but with a specially configured bottom end 52 which is complementary to the upper end of the front panel 20 . more particularly , the bottom end 52 is generally “ i ” shaped in cross - section having horizontal tabs 54 and 56 projecting laterally from both sides of the insert 50 and dimensioned to fit into the slot 28 in the upper end of the front panel 20 . to stabilize the insert 50 on the front track 10 , two additional horizontal tabs 58 and 60 are spaced vertically above tabs 54 and 56 . the tabs 58 and 60 will rest on the top of the opposed noses 36 and 34 . it will be noted that tabs 58 and 60 are generally arcuate and concave in cross section to nest on top of the front panel noses 36 and 34 . all of the surfaces , ribs , slots and recesses are straight , linear projections extending the full length of the front track 10 and insert 50 . the interior and end dividers 14 , 16 , 18 , which are used in some applications , will now be described . in some aspects the end and the interior dividers have the same construction as each other . before specifically describing the end dividers 16 , 18 , it will be noted that in accordance with the preferred embodiment of this invention the same end divider 16 or 18 can be used to close both ends of the add - on , self - facing unit . the end dividers 16 , 18 are substantially identical to each other and are arranged opposite each other as mirror images . further discussion will relate only to end divider 16 unless specifically stated otherwise , it being understood that the discussion relates equally to end divider 18 . the same reference numerals are used to identify aspects of end divider 18 as end divider 16 , and where an aspect is only seen on one of the end dividers 16 , 18 in the drawings , it will be understood that the feature is also present on the other end divider 18 , 16 . the end divider 16 illustrated in fig1 , and 5 includes a vertical panel 72 , a horizontal section 74 , and a second vertical , shorter panel 76 spaced from and generally parallel to the longer , vertical panel 72 . the top surface of the horizontal section 74 forms a support ledge 78 extending the length of the end divider 16 . with specific reference to fig1 and 2 , slots 80 are provided at both ends of the divider 16 in the lower edge of the vertical panel 72 and shorter vertical panel 76 . these slots 80 are aligned and sized to fit over the rib 40 on the front track 10 and the rib 40 r on the rear track 12 . through the interengagement of the ribs 40 and 40 r and the slots 80 , the end dividers 16 , 18 are held in place between the front and rear tracks 10 , 12 . to prevent the end dividers 16 , 18 from moving vertically relative to front and rear tracks 10 , 12 the front and rear ends of the horizontal section 74 are positioned beneath the recess 38 on the front track 10 and recess 38 r on the rear track 12 and thereby held in place by the webs 30 and 30 r and the lips 37 , 37 r ( fig2 ). it will be noted that to close the right and left ends of the add - on , self - facing tray the same end pieces 16 , 18 are used with one being reversed or turned end for end with respect to the other . when the tray is assembled , product is supported on the ledges 78 and between the front and rear tracks 10 , 12 . in the embodiment illustrated in fig1 - 5 the rear track 12 will be suitably elevated with respect to the front track 10 so that product displayed in the unit will be fed by gravity toward the front of the unit as one or more products are removed . to facilitate this gravity feed a plurality of pointed , relatively spaced ribs 90 ( fig5 ) are provided on the upper surface of ledges 78 . fig1 provides an example of how the end dividers 16 , 18 would be positioned to provide a gravity feed of product , where the product would span the space between the end dividers 16 , 18 and slide on the projections 90 . the interior divider 14 is illustrated in fig1 and 7 , and includes similar aspects as the end dividers 16 , 18 with some modifications . for example , the vertical panel 72 is centrally - located on the interior divider 14 , and the interior divider 14 includes a shorter vertical panel 76 on each side . the horizontal section 74 of the interior divider 14 also includes support ledges 78 and ribs 90 on both sides of the vertical panel 72 . the interior divider includes slots 80 similar to those of the end dividers 16 , 18 . fig1 illustrates a gravity feed arrangement including end dividers 16 , 18 on either side of the interior divider 14 . product would span the space between the end dividers 16 , 18 and the interior divider 14 on either side of the interior divider &# 39 ; s vertical panel 72 , such that two columns of product would be slidable on the projections 90 of the dividers 14 , 16 , 18 . again it will be noted that all surfaces , panels , ledges and ribs are straight linear projections extending the full length of the interior and end dividers 14 , 16 , 18 , except the vertical panels 72 , which are truncated to permit the ends of the dividers 14 , 16 , 18 to be inserted under the recesses 38 , 38 r as described above . the basic self - facing unit described to this point can be adapted for a spring feed of the displayed product toward the front of the unit in one of two variations : a center pusher and a side pusher . in the center pusher variation , illustrated in fig1 , and 12 , a pusher track 100 is positioned between the end dividers 16 , 18 . a pusher track 100 may also be positioned on either side of the interior divider 14 illustrated in fig1 , between the interior divider 14 and the end dividers 16 , 18 . the pusher track 100 includes aligned slots 102 in the front and rear ends that fit onto ribs 40 and 40 r . in addition , the pusher track 100 is provided with two relatively spaced horizontal ledges 110 and 112 which extend beneath the recesses 38 , 38 r to be held in place by the webs 30 , 30 r and lips 37 , 37 r in the same fashion as the dividers 14 , 16 , 18 . ledges 110 and 112 are provided with a plurality of relatively spaced , pointed ribs 114 ( see fig1 ) for the same purpose as ribs 90 on the dividers 14 , 16 , 18 . a centrally located , u - shaped in configuration recess 118 extends down the center of the pusher track 100 and between ledges 110 and 112 . ledges 110 and 112 provide overhanging lips 119 on either side of the recess 118 . the recess 118 and the lips 119 extend the length of the pusher track 100 . the ledges 110 , 112 , recess 118 , ribs 114 , and lips 119 of the pusher track 100 are substantially straight and linear and extend the full length of pusher track 100 . pusher plate 120 is positioned in and extends above the recess 118 ( see fig1 and 2 ). more specifically , pusher plate 120 includes a base which is made up of two oppositely facing c - shaped in cross section members 124 and 126 . these c - shaped members 124 , 126 define slots which engage the lips 119 of the pusher track 100 . a planar panel 132 is positioned above the c - shaped members 124 and 126 and is integrally molded therewith . a coil spring 134 ( fig1 ) has one end fastened to the front track 10 . the coil spring 134 extends through the space defined by recess 118 and the coiled portion of the spring 134 rests in a channel 137 defined on the back face of planar panel 132 . the channel 137 is defined between two angular ribs 136 and 138 molded to the rear face of panel 132 and to a horizontal portion 140 , from which the c - shaped members 124 , 126 depend . with this arrangement , the pusher plate 120 can be slid in the recess 118 toward the rear track 12 with product being filled between the pusher plate 120 and the front track 10 . when the desired number of products are loaded into the tray , the product holds the pusher plate 120 in spaced relationship from the front track 10 against the biasing force of the coil spring 134 . as product is removed from the front of the unit , the pusher plate 120 under the influence of the spring 134 urges the product toward the front track 10 . it will also be noted that the horizontal portion 140 extends over and is supported on the ledges 110 , 112 of the pusher track 100 and the ledges 78 of the end dividers 16 , 18 . a second version of the mechanically fed unit is illustrated in fig6 , and 13 . this side - mounted pusher assembly includes an adapted end divider 200 in combination with an above - described end or interior divider 14 , 16 , 18 . because the adapted end divider 200 includes many of the same structural aspects as the dividers 14 , 16 , 18 described above , the same reference numerals are used in fig6 , and 13 where appropriate . the pusher assembly includes a pusher plate 204 which is attached to and movable on the modified end divider 200 . more particularly , in this modification , the vertical panel 208 of the modified end divider 200 is provided with a slot 212 . this slot 212 includes a back wall 216 which is substantially parallel to and non - coplanar with the rest of the panel 208 . the slot 212 also includes two l - shaped projections 220 which project from the opposite side of panel 208 . the l - shaped members 220 terminate in spaced relationship defining an opening 224 to the slot 212 . turning to fig9 the pusher 204 includes a t - shaped in cross section tab 228 which fits into the slot 212 to hold the pusher 204 in and allow it to move relative to slot 212 . the side pusher 204 includes a front panel 232 , and two ribs 236 ( one of which is visible in fig9 ) which define a channel on the rear of panel 232 . a coil spring 240 fits into the channel . the end 244 of the coil spring 240 is u - shaped and fits over the front edge of the back wall 216 to an anchor the coil spring 240 . with this arrangement , the pusher 204 can be moved along the length of the panel 208 to allow products to be loaded into the unit and then , in the same manner as the previously described pusher 120 , the spring 240 will urge the products forward as a product is removed . the surfaces , ribs and slots of the modified end divider 200 are all straight , linear projections extending the full length of the end divider . to add to the versatility of this unit , it will be noted that an interior divider 14 can be modified to have the vertical panel 208 , and may be used with an end divider 16 , 18 with or without the slots 212 to accommodate the side pusher . with this arrangement , two or more side - by - side gravity feed units can be provided . therefore , the basic parts can be assembled with two spaced end dividers to receive product therebetween . with this configuration , the units can be set up to accommodate a single row of product or multiple adjacent rows of products , and with different configurations . as mentioned above , some arrangements of the dividers 14 , 16 , 18 , 200 are shown in fig1 - 13 .
a self - facing , add - on shelf system is made up of universal base , divider , front , and rear sections . universal in the sense that these sections form basic building sections for constructing shelf systems of various sizes and operational mode . the front and rear track sections are identical and can be combined with various combinations of bases , dividers and end sections to provide systems of different , desired widths . the depth of the self - facing shelf is generally set by the depth of the shelf with which it is to be used . the individual sections can be selected and combined to provide center pusher , side pusher , and gravity feed types of self facing s systems . the bases , dividers and end sections are configured such that they can be extruded and interlock in assembly .