Abstract:
A spring-driven pusher assembly of a merchandise dispenser in which the spring is carried entirely on the pusher assembly behind the articles being dispensed to thereby eliminate any interference problems with RF signals or the like used for purposes of determining inventories and the like. Preferably, the spring is a spiral spring that rotates a drive wheel when the spring uncoils. The drive wheel cooperatively engages a guide track on the base of the dispenser, and the rotation of the drive wheel causes the pusher assembly to advance along the guide track toward the dispensing end of the dispenser. A method of dispensing merchandise is also provided.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to a spring-driven pusher for use in a merchandise dispenser to automatically feed merchandise to a dispensing end of the dispenser. The present invention also relates to a merchandise dispenser utilizing the pusher assembly and to a method of dispensing merchandise.  
         [0002]     An example of a merchandise dispenser having a spring-driven pusher is disclosed by U.S. Pat. No. 6,464,089 B1 issued to Rankin, VI and assigned to Vulcan Spring &amp; Manufacturing Company, the assignee of the present application. Other examples of merchandisers are provided by U.S. Pat. No. 4,303,162 issued to Suttles; U.S. Pat. No. 5,634,564 issued to Spamer et al.; U.S. Pat. No. 5,012,936 issued to Crum; U.S. Pat. No. 5,562,217 issued to Salveson et al.; U.S. Pat. No. 5,878,895 issued to Springs; U.S. Pat. No. 5,131,563 issued to Yablans; U.S. Pat. No. 5,190,186 issued to Yablans et al.; U.S. Pat. No. 3,342,536 issued to Cohen; U.S. Pat. No. 4,351,439 issued to Taylor; U.S. Pat. No. 4,729,481 issued to Hawkinson et al.; and U.S. Pat. No. 5,665,304 issued to Heinen et al. and by UK Patent Application No. GB 2297241A.  
         [0003]     Such dispensers are typically utilized in retail stores, outlet stores and the like to store and display products and to permit products to be removed therefrom. The dispensers are typically provided with a forward feeding pusher so that a stacked row of identical products located in front of the pusher is biased toward the front dispensing end of the dispenser. Thus, when one of the products from the front end is removed, the products remaining in the row are pushed forward. Such a pusher typically projects from a track located below the products. However, it can also depend from a track located above the products or extend laterally from a track extending adjacent the sides of the products. Yet another alternative is for the pusher to extend from a substantially vertical track and be utilized to up-feed or down-feed a stacked column of products.  
         [0004]     Various hand-held electronic devices can be used to track inventory, set pricing information, or perform other functions with respect to merchandise stored in dispensers. For example, such a device may utilize radio frequency energy, signals or the like to read and/or write to electronic identification tags on the products or at the front of a display. Metal articles, such as metal springs in the dispensers, can interfere with the proper functioning of such devices.  
         [0005]     Thus, although the above referenced merchandiser assemblies may be satisfactory for their intended purposes, there is a need for a spring-driven pusher device and dispenser that eliminates any possible interference with radio frequency and like signals. Preferably, the pusher should permit ready adjustment of the pushing force so that the same pusher device and spring can be utilized regardless of the shape, weight, surface texture, or size of the stored and displayed product. Further, the pushing force should be capable of precise and fine adjustment so that the pusher can be set to provide a proper amount of pushing force specifically required for the selected product. In addition, the pusher assembly and dispenser should be inexpensive to manufacture, easy to assemble and operate, and require only a minimum of effort and skill to adjust.  
       SUMMARY OF THE INVENTION  
       [0006]     More specifically, the present invention provides a pusher assembly that is movable along a path of travel on a merchandise dispenser. The assembly includes a spring for exerting a force that resiliently urges a pusher in a dispensing direction on the dispenser. The spring is entirely contained within, and carried by, the pusher assembly for movement therewith. Preferably, the spring is a spiral spring having multiple coplanar windings, and the assembly includes a drive wheel that rotates and moves the assembly forward via the force exerted by the spring.  
         [0007]     According to another aspect of the present invention, a merchandise dispenser is provided having the above referenced pusher assembly. The dispenser includes a base unit having a front dispensing end and an opposite end with the pusher assembly being movable along a path of travel between the opposed ends. A guide track cooperatively engages the pusher assembly and defines the path of travel of the pusher assembly on the base unit. Preferably, the guide track engages the drive wheel of the pusher assembly so that rotational movement of the drive wheel results in forward movement of the pusher assembly on the base unit.  
         [0008]     According to yet another aspect of the present invention, a method of dispensing merchandise is provided. A series of articles are positioned in a merchandise dispenser ahead of a pusher assembly which urges the articles along a path of travel to a dispensing end of the dispenser. The method includes adjusting the tension of a spring on the pusher assembly to set a desired amount of pushing force exerted by the pusher assembly. The spring is contained entirely within the pusher assembly for movement therewith along the path of travel. Preferably, the method includes engaging a drive wheel of the pusher assembly with a guide track on the dispenser so that, when the spring unwinds, the drive wheel rotates resulting in forward movement of the pusher assembly along the guide track. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The foregoing and other objects, features and advantages of the present invention should become apparent from the following description when taken in conjunction with the accompanying drawings, in which:  
         [0010]      FIG. 1  is a perspective view of a merchandise dispenser having a pusher assembly according to the present invention;  
         [0011]      FIG. 2  is a broken bottom view of the merchandise dispenser illustrated in  FIG. 1 ;  
         [0012]      FIG. 2A  is a magnified view of the drive wheel and guide track illustrated in  FIG. 2 ;  
         [0013]      FIG. 3  is a cross-sectional view of the pusher assembly illustrated in  FIG. 1  along line  3 - 3  in which the pusher assembly is in a position engaged with the guide track;  
         [0014]      FIG. 4  is a cross-sectional view of the pusher assembly in a position disengaged from the guide track; and  
         [0015]      FIG. 5  is a cross-sectional view of the pusher assembly illustrated in  FIG. 3  along line  5 - 5 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     As best illustrated in  FIG. 1 , a merchandise dispenser  10  according to the present invention includes a base unit  12  and a pusher assembly  40  for automatically feeding merchandise  14  (shown in phantom lines) stored and displayed in the dispenser  10  toward a dispensing end  16  of the base unit  12 . In the illustrated embodiment, the base unit  12  extends under the merchandise  14  and supports the merchandise  14  thereon, and pusher assembly  40  feeds the merchandise  14  to a front end  16  of the base unit. Although not illustrated, the merchandise dispenser  10  can also be arranged to provide an up-feeding, down-feeding, side-feeding or top-feeding dispenser.  
         [0017]     The merchandise  14  can be, for instance, individual boxes, bags, containers, cartons or the like containing a food or other product positioned in a single file row one behind the other within the dispenser  10 . The leading box  18  is located at the front dispensing end  16  of the base unit  12 , and upon removal by a customer or the like, the pusher assembly  40  urges the remaining boxes  14  forward to provide a new leading box adjacent the front dispensing end  16 .  
         [0018]     The base unit  12  can include a base panel  20  having a merchandise supporting surface  22  and an underside  24  extending between the front dispensing end  16  and an opposite end  26 . As stated above, alternate arrangements can be utilized in which the base panel  20  extends above the merchandise or laterally of the merchandise. In the illustrated embodiment, base unit  12  also includes non-adjustable sidewalls  28  as well as adjustable sidewalls  30 . The adjustable sidewalls  30  can be positioned at various spaced-apart locations on the base panel  20  to permit the base unit  12  to be used with merchandise of a variety of sizes. Thus, regardless of the size of the merchandise, the adjustable sidewalls  30  can be positioned to restrict lateral movement of the merchandise  14  relative to the intended path of travel toward the dispensing end  16 .  
         [0019]     The base unit  12  according to the present invention has a guide track, or rail,  32  in cooperative engagement with the pusher assembly  40 . In the illustrated embodiment, the guide track  32  is secured to the underside  24  of the base panel  20  adjacent a centrally-extending elongate open slot  34 . The pusher assembly  40  rides and is captured within slot  34  and includes means for engaging the guide track  32  underneath the base panel  20 . Preferably, the slot  34  includes a widened portion  36  at end  26  of panel  20  to enable installation of the pusher assembly  40  on the base unit  12  and/or removal of the pusher assembly  40  from the base unit  12 .  
         [0020]     The pusher assembly  40  includes a pusher  42  projecting from the base panel  20  to a position for engaging a rearward most item  38  of the single file row of merchandise  14  within the dispenser  10 . A spring  44  is contained entirely within a housing  46  that extends rearwardly (relative to the dispensing direction of the dispenser  10 ) from the pusher  42  and that is carried by and moves with the pusher assembly  40 . A pair of flanges  48  depend from the housing  46  and capture the edges of the base panel  20  that form the open slot  34 . This is best illustrated in  FIGS. 3 and 4 . Thus, the pusher assembly  40  is located behind the row of merchandise  14 , is captured within the slot  34 , and is movable along a path of travel defined by the slot  34 .  
         [0021]     Preferably, the pusher assembly  40  includes a drive wheel  50  or the like for engaging the guide track  32  on the base unit  12 . In the illustrated embodiment, the drive wheel  50  depends from the housing  46  to a position beneath the base panel  20 . As best illustrated in  FIGS. 2 and 2 A, the drive wheel  50  can be a gear-toothed wheel and the guide track  32  can have a gear toothed edge  52 . Thus, rotation of the drive wheel  50  results in forward movement of the pusher assembly  40  within the slot  34  along the guide track  32  toward the dispensing end  16  of the base unit  12 . Although not illustrated, alternate drive wheel and guide track structures can be utilized. For instance, the guide track can be provided as a belt or the like in frictional engagement with a non-gear-toothed drive wheel.  
         [0022]     As best illustrated in  FIGS. 3-5 , the spring  44  can be a spiral spring having multiple windings  54  extending within a common plane. The outer end  56  of the spring  44  can be secured within the housing  46  such that it is prevented from movement relative to the housing  46 . See  FIG. 5 . The inner end  58  of the spring  44  can be secured to an arbor  60  which interconnects to the drive wheel  50  at one end thereof and an adjustment control knob  62  at an opposite end thereof. The spiral spring  44  exerts a force, for instance as viewed in  FIG. 5 , in a counterclockwise direction about the arbor  60 . Thus, when an item of merchandise is removed form the dispenser, the spring  44  unwinds and rotates the arbor  60  until the forward most item of merchandise confronts the wall at the dispensing end  16  of the dispenser  10 .  
         [0023]     The spiral spring  44  can be a flat metal self-coiling spring such as a steel variable force spring or a steel power spring. The spring  44  can also be a flat strip of metal or plastic which is placed in a coiled condition. The pushing force provided by the spring  44  gradually reduces as the pusher  42  approaches the front end  16  of the base unit  12  and as the spring  44  transitions from being retracted in a relatively tightly-coiled condition to a relatively loosely-coiled condition. This provides the advantage that the spring  44  exerts a maximum force when the dispenser  10  is fully loaded with a row of articles  14  and exerts a progressively reduced amount of force as the leading articles of the row are removed.  
         [0024]     Preferably, the amount of pushing force exerted by the pusher assembly  40  is adjustable. This enables a single sized spring  44  to be used with different types of merchandise articles within a range of sizes, shapes, weights and/or surface textures that may require different amounts of force to be properly advanced within the dispenser. Obviously, heavier articles and articles that do not readily slide across the base panel  20  due to friction require greater pushing forces than lightweight articles and articles that are capable of readily sliding across the base panel  20 . In addition, the use of too strong a force with relatively delicate articles may damage the articles; whereas, the use of too weak a force may result in the failure of the articles to be properly advanced within the dispenser.  
         [0025]     As best illustrated in  FIGS. 3 and 4 , control knob  62  can be used to rotate arbor  60  (clockwise as viewed in  FIG. 5 ) to tighten the windings  54  of the spring  44  or to rotate arbor  60  (counterclockwise as viewed in  FIG. 5 ) to loosen the windings  54  of the spring  44 . Before making such an adjustment, the drive wheel  50  should be disengaged from the guide track  32 . As best illustrated in  FIG. 3 , the drive wheel  50  is resiliently maintained in engagement with guide track  32  due to the force exerted by a spring  64  located between the housing  46  and the underside of the control knob  62 . However, as best illustrated in  FIG. 4 , the drive wheel  50  can be disengaged from guide track  32  by pressing downwardly on control knob  62  to compress spring  64 . In the disengaged condition illustrated in  FIG. 4 , the knob  62  can be rotated thereby permitting the desired adjustment (ie., tightening or loosening) of the coiled condition of the spiral spring  44 . Thereafter, the knob  62  can be raised to re-engage the drive wheel  50  with the guide track  32 . Thus, the pusher assembly  40  can be set to deliver a desired pushing force within a wide range of forces and the same pusher assembly  40  and spring  44  can be used to properly feed a row of relatively heavy articles and be reset to properly feed a row of relatively lightweight articles.  
         [0026]     In use, the pusher assembly  40  can be pulled toward end  26  of the base unit  12  so that the dispenser  10  can be loaded with a row of articles  14 . If desired, the force exerted on the articles  14  by the pusher assembly  40  can be adjusted as discussed above. If the pushing force is determined to be too weak for a particular row of articles, the tension of the spring  44  can be increased by tightening the windings  54 . Alternatively, if the pushing force is determined to be too strong for a particular row of articles, the tension of the spring  44  can be reduced by loosening the windings  54 .  
         [0027]     The base unit and other parts of the dispenser  10  can be made substantially of plastic or other non-metallic materials. The spring  44  carried by the pusher assembly  40  can be made of steel or the like since the entire spring  44  is located behind the row of articles  14  and since no part of the metal spring  44  extends in front of any articles  14 . Thus, the pusher assembly  40  and dispenser  10  according to the present invention eliminates any possible interference with the proper functioning of RF electronic devices used for determining inventories or the like.  
         [0028]     Further, the pusher and dispenser according to the present invention provides a universal device for use in forward, side, top and/or up feeding various products regardless of the amount of pushing force required. The pushing force can be readily adjusted as needed, and can be accurately set to ensure proper feeding of a stacked row or column of articles to a dispensing end of the merchandise dispenser.  
         [0029]     While a preferred pusher assembly, merchandise dispenser and method have been described in detail, various modifications, alterations, and changes may be made without departing from the spirit and scope of the present invention as defined in the appended claims.