Abstract:
Self-fronting merchandise pusher systems. Numerous products in a store are merchandised on shelves and spring-biased pushers are used to urge products toward the front edge of the shelf on which the products are displayed and stored. Each pusher is generally mounted on a track, and each pusher track is generally positioned between two divider walls or between a divider wall and an end wall. Each pusher is independently biased towards the front of the shelf. The system provides an improved apparatus for coupling any of the longitudinal members, such as the pusher tracks, divider walls or integrated divider/pusher tracks, to the shelf-mounting member. The shelf-mounting member forms an alignment track for selective and slidable coupling with the longitudinal members. The coupling is designed to resist sliding when the coupling is under torque.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a self-fronting merchandise pusher system having longitudinal members, such as a divider wall and a pusher track, that are slidably coupled to a shelf-mounting member.  
         [0003]     2. Background of the Related Art  
         [0004]     Numerous products sold in retail stores are displayed and stored on gondola shelves. There are several designs of self-fronting pusher systems that push rows of products within channels toward the front of the shelf near the aisle. These self-fronting pusher systems typically involve divider walls that form product channels therebetween, and a spring-urged pusher track with a pusher adapted to contact the last product in the row and urge the row forward in the channel defined by the divider walls. The divider walls and the pusher tracks are generally secured to the shelf using a shelf-mounting member secured along the front edge of the shelf.  
         [0005]     The pusher serves to keep the product “fronted” at the front shelf edge against the shelf-mounting member so that the product is easier for the consumer to see. This system also provides a more organized and aesthetically pleasing array of products on the shelf and makes inventory and restocking of products easier.  
         [0006]     Existing merchandising pusher systems, such as those disclosed in U.S. Pat. No. 5,730,320 issued to David and U.S. Pat. No. 5,131,563 issued to Yablans, include a segregated horizontal space, usually separated into a plurality of channels using dividing walls, and a pusher track with a pusher positioned between each pair of dividing walls. The pushing surface on the pusher is generally a rigid vertical plane urged forward by a coiled spring. Typically, the pushing surface is oriented in a plane parallel to a front retaining wall at the front of the shelf to retain the product on the shelf. The front retaining wall generally keeps the pushed products from spilling from the front edge of the shelf.  
         [0007]     Certain products, such as toothbrushes, for example, are often sold in packaging with a height that is several times the width. Other products may have a more squared cross-section, and still others may have a longer, flatter cross-section. Consequently, it may be necessary to display many of each of several shapes and sizes of products on a shelf. As a result, a pusher system should accommodate a variety of package shapes and sizes, and be flexible enough to allow repositioning of the divider walls and pusher tracks on the shelf without requiring that the products be completely removed from the shelf for repositioning of the divider walls and pusher tracks, followed by replacement of the products onto the shelf.  
         [0008]     While slidable divider walls and pusher tracks may facilitate reorganization of the shelf without the necessity of removing the products, the inadvertent sliding of the couplings between the shelf-mounting member and the divider walls or the pusher tracks is undesirable because unwanted movement of the divider walls or the pusher tracks can result in disruption of fronting of the product on the shelf or interference between products in adjacent channels formed by pairs of adjacent dividing walls. As a result, many self-fronting systems include non-sliding or sliding-resistant couplings that prevent or resist sliding of the dividing wall or the pusher track relative to the shelf-mounting member. For example, these non-sliding or sliding resistant couplings often employ rearward protruding teeth disposed on the shelf-mounting member for engaging with frontward protruding teeth disposed on the divider wall or the pusher track. Other systems employ a broad tongue and groove coupling, often having an interference fit, for firm gripping of the divider wall or pusher track to the shelf-mounting member to resist sliding. Still other self-fronting systems include double tongue and groove couplings that provide excessive gripping in the coupling between the shelf-mounting member and the divider wall or pusher track to prevent sliding. Generally, these systems require elevating the rearward-most end of the divider wall or pusher track from its normal position on the shelf in order to release the coupling and allow movement or adjustment of the divider wall or pusher track. Accordingly, it is necessary for store personnel to remove some or all of the product from the shelf before repositioning rows. The process must be repeated until the desired position is obtained, thereby consuming a great deal of time and effort to manage the product.  
         [0009]     Therefore, there is a need for a self-fronting merchandise pusher system that allows smooth and controlled movement of the divider walls or pusher tracks relative to the shelf-mounting member without removal of the shelved product and without the use of excessive force on the shelving system components. It would be desirable if this system would also prevent unwanted movement of the divider walls or pusher tracks relative to the shelf-mounting member.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention is directed to a self-fronting merchandise pusher system for use in displaying and dispensing product in retail stores. The system includes a transverse shelf-mounting member securable to a top front edge of a shelf and a plurality of longitudinal members selected from divider walls, pusher tracks, and combinations thereof. The invention incorporates spring-biased pushers that are used to urge product toward the front edge of the retail shelf. The width of the pusher corresponds generally to the width of the narrowest product to be managed and fronted by the system. The removable divider walls extend longitudinally and vertically on either side of each pusher, or opposite a pusher from an end wall.  
         [0011]     The present invention provides an improved coupling that allows only deliberate and controlled movement of a merchandise divider wall or a merchandise pusher track relative to a shelf-mounting member. The apparatus comprises unique coupling elements, such as a tongue and groove arrangement, with limited contact between the coupling elements when the coupling is in its secured or attached position. The tongue (or the groove) may be integrally formed onto or near the end of the longitudinal elements (i.e., divider wall and merchandise pusher track), and the corresponding groove (or the tongue) may be integrally formed onto the shelf-mounting member that is secured along the top front edge of the shelf.  
         [0012]     The coupling elements have contact surfaces therebetween that preferably comprise different materials. The physical design and tolerances of the coupling, in combination with the different materials, allows the coupling with limited points of contact to resist inadvertent sliding during normal shopping or restocking use, yet readily provides sliding between the tongue and groove members of the coupling when a deliberate and directed sliding force is applied to the divider wall or pusher track in a collinear direction along the length of the self-fronting member in order to reposition the pusher track or to modify the channel that provides for the product rows. The coupling is designed to resist sliding when the coupling experiences torque, typically meaning that the divider wall or pusher track has been displaced out of its perpendicular relationship with the shelf-mounting member to which it is coupled. However, the coupling permits sliding of the longitudinal members when there is substantially no torque on the coupling, such as when the divider wall or pusher track is generally perpendicular to the shelf-mounting member and a sliding force is applied to the coupling. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     So that the above recited features and advantages of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof that are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are, therefore, not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.  
         [0014]      FIG. 1  is a user perspective view of a self-fronting merchandise pusher system having an improved coupling for securing the divider walls and pusher track to the shelf mounting member.  
         [0015]      FIG. 2  is a user perspective view of the same self-fronting merchandise pusher system illustrating the divider walls angularly displaced in a manner that prevents the divider walls and pusher track from sliding relative to the shelf mounting member.  
         [0016]      FIG. 3  is a partially cross-sectional, side perspective view of a tongue and groove coupling, in accordance with the invention, before the divider wall and shelf-mounting member are coupled.  
         [0017]      FIG. 4  is a front elevation view of a divider wall being coupled to a shelf-mounting member in the self-fronting merchandise system.  
         [0018]      FIG. 5  is a partially cross-sectional side view of the tongue and groove coupling of  FIG. 3  after the divider wall and shelf-mounting member are coupled.  
         [0019]      FIG. 6  is a schematic bottom view of two couplings illustrating how the coupling of a longitudinal member resists sliding under torque, but is manually slidable under forces applied along the line of the alignment track.  
         [0020]      FIG. 7  is a partially cross-sectional, side perspective view of a tongue and groove coupling having the groove in the shelf-mounting member and the tongue in the divider wall. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]     One embodiment of the present invention is shown in the attached drawings. It should be understood that the self-fronting merchandise system may be configured in various manners that all serve the purpose of the invention. The primary purpose of the invention is to save time and labor in adjusting rows of merchandise on store gondola shelves. The apparatus of the present invention allows movement of divider walls and pusher tracks into a desired alignment along the shelf without requiring removal of merchandise managed by these devices, while preventing unwanted movement and misalignment of rows of merchandise that can result from unwanted or inadvertent movement of divider walls and pusher tracks.  
         [0022]     The present invention uses two ways to resist sliding contact in the coupling between the longitudinal members and the elongated coupling element of the shelf-mounting member. The first way is by physical shape: the coupling is designed to cause and rapidly increase physical interference between the longitudinal members and the shelf-mounting member whenever the longitudinal member is angularly displaced from its substantially perpendicular relationship with the shelf-mounting member. For example, the inwardly protruding surfaces of the rails that define the groove on the end of a longitudinal member is designed to forcibly engage or “bite” the alignment track formed in shelf-mounting member upon angular displacement of the longitudinal member. The groove defined by the inwardly protruding surfaces of the rails permits sliding relative to an alignment track tongue when the longitudinal member is in a perpendicular configuration, but the groove will physically interfere with the upwardly protruding tongue of the shelf-mounting member when the longitudinal member is displaced from its perpendicular relationship relative to the shelf-mounting member (also referred to as a “front rail member”). The physical interference causes a biting action or high friction that resists sliding contact.  
         [0023]     The second way to resist sliding contact is by incorporating dissimilar materials in the coupling elements. Many combinations of materials provide a high coefficient of friction there between, and the selectively slidable coupling of the present invention is achieved using this materials selection approach. The materials from which the shelf-mounting member and the longitudinal members are made are designed to provide for smooth and controlled sliding movement of the coupling. For example, but not by way of limitation, styrene is generally a hard plastic material that is often used in making model cars and other products. Styrene will slide reasonably well on styrene, and styrene on styrene is therefore deemed to have a generally low coefficient of friction that would more readily permit sliding contact between two components where both are made of styrene. However, in order to enhance the biting effect of the physical interference described above, the present invention uses a second material that provides for a relatively higher coefficient of friction to better resist sliding contact when the inwardly protruding gripping surfaces of the groove bite into the neck of the tongue.  
         [0024]     The materials selection should maintain certain objectives such as a favorable coefficient of friction to prevent unwanted sliding of the longitudinal members relative to the shelf-mounting member, low costs, suitability for contact with consumers, wear resistance and other factors. Polyethylene terephthalate (PET) or a modified polyethylene terephthalate copolymer (such as a glycol-modified PET or “PETg”, available from Eastman Chemical Company under the trademark Provista®) is a good material for use in the shelf-mounting member in combination with styrene or acrylonitrile butadiene styrene (ABS) in the longitudinal members. PETg offers excellent transparency, clarity and high gloss for use with shelf-mounting members that include a display, and it does not whiten when stressed. This offers the user a visually clear product, which makes it good for use in shelf-mounting members that are integral with a front shelf display. PETg also provides toughness with flexibility and impact resistance for providing durability, good chemical resistance, and is approved by the FDA (standard 21 CFR 177, 1315) for contact with foods so that it can be used for virtually all shelf applications. Finally, PETg provides good UV resistance, with the use of UV grades that are available. Most importantly, however, PETg is softer than styrene or ABS in order to enhance the biting effect between the opposing coupling elements. Examples of other materials that are suitable for use in the shelf-mounting member include, without limitation, butyrate, polycarbonate, and other polyesters.  
         [0025]      FIG. 1  is a user perspective view of a self-fronting merchandise pusher system having an improved coupling  10  for securing longitudinal members, such as divider walls  40  and a pusher track  30 , to the shelf mounting member  24 . The shelf mounting member  24  is itself secured to the shelf  26  in some manner, such as with screws or clips. The pusher track  30  is positioned between two adjacent divider walls  40 . Typically, the distance between adjacent divider walls  40  is adjusted to the width of a product to be received between the two divider walls. The pusher track  30  is typically positioned midway between these two divider walls  40  in order for the pusher  32  to apply a forward directed push against the back and center of the product. The term “product” or “the product,” as used herein, is intended to encompass one or more units of an item that is on display or for sale.  
         [0026]     While the design of the pusher track  30 , including the pusher  32  and a coil spring (not shown), is an important element of a self-fronting merchandise pusher system, the present invention deals primarily with the coupling of the pusher track  30  and divider wall  40  to the shelf mounting member  24 . Accordingly, the invention is not limited to any particular pusher track, pusher, coil spring, or other aspect of urging a product forward. Explanations of pusher track designs and operations may be found in U.S. Pat. Nos. 5,730,320 and 5,131,563, which patents are incorporated by reference herein.  
         [0027]     As shown in  FIG. 1 , the divider walls  40 , as well as the pusher track  30 , may be slid in either direction (right or left as shown) along the shelf mounting member by manually applying a force along the coupling element  22  that is part of the shelf mounting member  24 . In this manner, the spacing of the divider walls  40  and the pusher track  30  can be quickly adjusted. It should be recognized that the shelf  26  may include any number of additional divider walls  40  and pusher tracks  30  in order to manage products over some or all of the shelf space. Typically, a self-fronting merchandise pusher system will have divider walls and pusher tracks disposed in an alternating pattern that begins and ends with a divider wall, although a specialized end wall may be used at the extreme ends of the system. However, nothing prevents multiple pusher tracks from being used side by side, for example to push forward a wide or heavy product.  
         [0028]      FIG. 2  is a user perspective view of the same self-fronting merchandise pusher system illustrating the divider walls  40  being angularly displaced in either direction (as shown by arrows  38  and  39 ) in a manner that the divider walls  40 , representative of any of the longitudinal members, resist sliding along the coupling element  22  of the shelf mounting member  24 . It should be recognized that while the position of a user&#39;s hands  51 ,  53  is the same as shown in  FIG. 1 , the manual force and/or other forces applied to the dividers  40 , as shown in  FIG. 2 , has apparently applied a torque to the coupling such that the dividers  40  have been angularly displaced. Such torque may similarly come from forces acting against the dividers  40  at a point some distance from the coupling  10 . The forces that cause torque may unintentionally occur during routine placement or withdrawal of products from the shelf, in which case the coupling will remain secured to its position, but may allow the divider to flex or tilt in one direction or another. While the divider walls  40  and the pusher tracks  30  may experience different forces during use, it is preferred that the pusher track  30  be designed with the same type of coupling as the divider walls  40 , so that angular displacement in either direction would cause the pusher track to resist sliding. Still, many of the benefits of the present invention would be realized if only the divider walls included the present coupling.  
         [0029]      FIG. 3  is a partially cross-sectional, side perspective view of a coupling  10 , in accordance with the invention. The coupling  10  is shown having coupling elements in the form of a tongue and a groove for securing the divider wall and shelf-mounting member together. The divider wall  40  has a base  42 . The bottom side  12  of the base  42  has a slidable coupling element, such as groove  14 , that runs generally transverse in the longitudinal divider wall, so that groove  14  is directed along the shelf mounting member  24  when the divider wall  40  is positioned to extend between two rows of product (not shown). A mating elongated coupling element, such as tongue  22 , is part of the shelf-mounting member  24  that runs along the front edge of the shelf  26 . The tongue  22  extends upward from the base of the member  24  and runs generally parallel to the shelf mounting member  24  to form an alignment track.  
         [0030]      FIG. 4  is a front elevation view of a divider wall  40  being installed in the self-fronting merchandise system. Once the tongue  22  and the groove  14  coupling elements are aligned, with the groove immediately above and parallel to the tongue, then the divider wall  40  is pushed downward so that the groove securely receives the tongue. Preferably, the tongue and groove fit tight enough that it may be difficult in some situations to couple the members with a purely translational downward motion. Rather, the divider  40  is more easily coupled by first pressing firmly downward on one side of the divider base  42  directly above the tongue  22  and groove  14  (for example with the thumb of the right hand in the direction of arrow  41 ), and then pressing firmly downward on the other side of the divider base  42  directly above the tongue  22  and groove  14  (for example with the thumb of the left hand in the direction of arrow  43 ).  
         [0031]     Similarly, the coupling  10  may fit tight enough that it will be difficult in some situations to de-couple or remove the longitudinal members from the alignment track with a purely translational upward motion. Furthermore, such an upward pulling could damage the connection between the shelf-mounting member  24  and the shelf  26 . Accordingly, it is preferred to remove the divider by applying a sideways force to the divider wall  40  (for example pulling the top of the divider in the direction of arrow  45 ) and then lifting.  
         [0032]      FIG. 5  is a partially cross-sectional side view of the tongue and groove coupling  10  of  FIG. 3  after the divider wall  40  and shelf-mounting member  24  have been coupled together in their normal operating relationship. Here, the tongue  22  is operationally secured and received within the groove  14 .  
         [0033]     The construction of the coupling  10  is important to its proper functioning. The groove  14  is defined by opposing rails  16  that flex to engage the tongue  22 . The degree of flexibility exhibited by the rails  16  is a result of both the plastic composition of the divider wall  40  and the thickness of the rails. In the preferred embodiment, a relief channel is formed on the back side of each of the rails  14  in order to facilitate flexing of the plastic rails. The optimum thickness of the rails partly depends upon the flexibility of the plastic composition selected for the divider walls, but determining an appropriate thickness is within the capabilities of one skilled in the art of manufacturing plastic components in light of the foregoing disclosure. The rails  16  should be dimensioned to maintain a gripping surface in contact with the neck portion of the tongue  22  for sliding resistance.  
         [0034]     The tongue  22  is also made of a plastic composition, preferably a different, softer plastic composition than the longitudinal members as discussed above, and preferably extends upward only a short distance in order to prevent the tongue from flexing or bending during coupling, decoupling or normal operational use. It is highly preferred, but not an absolute necessity, that the tongue  22  include an enlarged or bulbous distal end or head and that the groove  14  have a cooperating profile. In accordance with this preferred embodiment and other embodiments consistent with the invention, the primary contact between the tongue and the groove may occur along the necked portion  17  of the tongue  22 . In fact, a full-contact or tight fit between the tongue and groove in the region of the bulbous end of the tongue could cause negative effects, such as constant stress on the tongue and groove elements due to small variations in the dimensions of the parts. Rather, it is preferred that the groove have dimensions that allow for a small gap around the bulbous end of the tongue.  
         [0035]     FIGS.  6 (A) and (B) are schematic bottom views of two couplings  10  illustrating how the coupling resists sliding under torque, but is manually slidable under forces applied along the line of the coupling member  22  forming an alignment track on the shelf-mounting member  24 . In  FIG. 6 (A), the base  42  of a divider wall or other longitudinal member is under no appreciable torque and sits substantially perpendicular to the coupling element forming the alignment track (tongue  22 ) of the shelf-mounting member  24 . Accordingly, the rails  16  of the groove grip the neck  17  of the tongue  22 , but only under the forces of the flexed rails. By firmly pushing on the divider wall base  42  near the coupling  10  and in a direction along the shelf mounting member  24  (See either of the arrows  25 ), the base  42  will slide along the alignment track. Having a bulbous distal end on the tongue  22  prevents the tongue and groove from coming apart unintentionally during sliding.  
         [0036]     In  FIG. 6 (B), a force (See arrow  29 ) is applied against some portion of the divider wall (not necessarily the divider base as shown) at a point rearward of the coupling  10 . This force puts the coupling in torque, displaces the divider wall away from its substantially perpendicular position by some angle  27  and causes the rails  16  be pressed against the neck  17  with a force much larger than the mere flexing of the rails, as in  FIG. 6 (A). Now the rails  16  apply a force against the neck  17  that is proportional to the force  29  multiplied by the lever arm of the force (i.e., the distance from the coupling to the point where the force is applied). Because the amount of friction between two surfaces is proportional to the force applied between the surfaces, the force  29  creates so much friction that the coupling does not slide. By selecting the appropriate plastic compositions, the coefficient of friction is increased so that the presence of torque on the coupling has a significant and immediate effect on the ability to slide the components. Depending upon the softness of the materials and the magnitude of the forces, the torque may product a biting effect in which the edge of the harder coupling element digs into the softer coupling element to resist sliding.  
         [0037]     It is recognized that extensive sliding of the components may tend to wear away any small ridges or manufacturing artifacts that may exist between the coupling elements, such as the tongue  22  and the groove  14 , especially the gripping surface of the rails  16  or the neck  17 . This wear will tend to be self-limiting, since any wear will lead to lower flexing forces. Still, regardless of wear, torque applied against the coupling will still cause a high degree of friction that will resist sliding.  
         [0038]      FIG. 7  is a partially cross-sectional, side perspective view of a tongue and groove coupling similar to the couplings of  FIGS. 3-6 , but having a groove  60  forming part of the shelf-mounting member  24  and a tongue  62  forming part of the divider wall  40 . The design characteristics discussed above for the tongue  22  and groove  14  are still relevant to the design of  FIG. 7 . However, the base  42  must provide sufficient room on either side of the tongue  62  in order for the rails  64  of the groove element  60  to extend upward and receive the tongue  62 .  
         [0039]     Generally speaking, it is preferable to make the divider walls  40  and the pusher tracks  30  from a plastic that is more rigid than the plastic used to make the shelf-mounting member  24 . Rigid plastics generally have lower coefficients of friction and it is generally desirable to have low friction within the pusher track and low friction between the products and either the pusher track or the divider walls. A more flexible plastic can be used to make the shelf-mounting member, since the only point of friction for the shelf-mounting member during normal use is the coupling of the present invention. Accordingly, the composition of the shelf-mounting member can be specifically chosen to accommodate an appropriate amount of friction within the coupling. As discussed above, it is also desirable for the shelf-mounting member to be clear so that the full front of the product can be seen through the front wall of the shelf-mounting member.  
         [0040]     It will be understood from the foregoing description that various modifications and changes may be made in the preferred embodiment of the present invention without departing from its true spirit. It is intended that this description is for purposes of illustration only and should not be construed in a limiting sense. The scope of this invention should be limited only by the language of the following claims.