Abstract:
A conveyor guide wall constructed of a series of parallel columns of freely rotatable rollers. The rollers are mounted on rods retained within top and bottom rails. The rollers rotate on the rods to provide a guide that engages conveyed articles in low-friction rolling contact. Voids in the rollers increase the rollers&#39; flexibility and help absorb impacts with conveyed articles.

Description:
BACKGROUND 
       [0001]    The invention relates generally to power-driven conveyors and more particularly to guides positioned alongside or within a stream of conveyed articles. 
         [0002]    Guide walls are often used alongside, across, or within a stream of conveyed articles to guide the articles along a conveyor. Usually the walls have static surfaces along which the articles slide as they are being conveyed. Bead or roller rails, or guides, are used to replace the sliding friction of static guides with lower rolling friction. These low-friction guides are made of hard beads or rollers arranged in stacks on rods. The beads or rollers are free to rotate on the rods when contacted by an advancing article. Often the bead or roller guides are used as stops across a conveyor to divert articles to a side or as side rails along which articles can be registered. Because the beads or rollers are made of a hard material, articles can bounce off the rigid bead or roller on contact. The impact can damage the article or alter its alignment or orientation, which can degrade the transfer to another conveyor downstream. 
       SUMMARY 
       [0003]    One version of a conveyor guide wall embodying features of the invention comprises a plurality of columns of one or more rollers mounted between the top and bottom rails. Each of the roller columns is arranged to rotate on parallel axes of rotation. Each of the rollers includes a first side, a second side, and an outer periphery encircling the axis of rotation and extending axially from the first side to the second side. Voids extend through each roller from the first side to the second side between the outer periphery and the axis of rotation to absorb impacts against the outer periphery of the roller. 
         [0004]    In another aspect of the invention, a conveyor system embodying features of the invention comprises a conveyor conveying articles in a conveying direction along a conveying plane and a guide wall arranged perpendicular to the conveying plane to contact the articles. The guide wall includes rollers that are rotatable on axes of rotation transverse to the conveying plane and that have outer peripheries to contact the articles. Each of the rollers has a plurality of voids extending through the roller between the axis of rotation and the outer periphery to absorb impacts against the outer periphery of the roller by the articles as they are conveyed in the conveying direction. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is an isometric view of a section of a conveyor guide wall embodying features of the invention alongside a portion of a conveyor; 
           [0006]      FIGS. 2A and 2B  are isometric and side views of a roller in a guide wall as in  FIG. 1 ; 
           [0007]      FIG. 3  is an isometric view of a flanged sleeve bushing used in the roller of  FIGS. 2A and 2B ; and 
           [0008]      FIGS. 4A and 4B  are isometric and side views of a column of rollers as in the guide wall of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    A conveyor system embodying features of the invention is shown in  FIG. 1 . A conveyor  10 , which may be a conveyor belt as shown, a roller conveyor, or another kind of conveyor, advances articles  12  in a conveying direction  14 . In particular the conveyor, whether a belt or a roller conveyor, could include article-supporting rollers arranged to rotate in a direction oblique to the conveying direction  14  to push articles toward a side of the conveyor. A guide wall  16  along a side of the conveyor  10  prevents the conveyed articles  12  from falling off the side of the conveyor and also registers the articles along the side. 
         [0010]    The guide wall  16  comprises columns  18 ,  19  of stacked rollers  20  mounted between parallel top and bottom rails  22 ,  23 . In this example the rollers  20  in adjacent columns  18 ,  19  are vertically offset so that they can be interleaved in a high-density pattern. But the rollers could be vertically aligned in a lower-density pattern. Each column  18 ,  19  of rollers  20  rotates on an axis of rotation  24  that is transverse—in this example, perpendicular—to the conveying plane  26  of the conveyor  10 . To increase or decrease the pressure on the conveyor as the articles are conveyed along the guide wall  16 , the axes of rotation  24  can be angled forward or rearward in the conveying direction  14 —slightly off perpendicular to the conveying plane  26  of the conveyor  10 . For small articles a guide wall with only a single roller in each column may suffice. The rollers  20  rotate freely on their parallel axes of rotation  24  and contact the conveyed articles  12  in low-friction, rolling contact. 
         [0011]    One version of the rollers  20  is shown in more detail in  FIGS. 2A and 2B . The roller  20  has an outer periphery  28  extending axially across the width of the roller between a first side  30  and an opposite second side  31 . A central bore  32  through the roller  20  defines its axis of rotation  24 . A bushing  34  is received in the central bore  32  by a press-fit, overmolding, or other means of attachment. The bushing  34  shown in  FIG. 3  is a flanged sleeve bushing with a flange  36  at one end of a sleeve  38 . The bushing  34  is made of a rigid plastic material, such as nylon, PEEK, or a hardened PTFE, or of a metal material such as aluminum, steel, or stainless steel, for durable, wear-resistant, low-friction rotational contact with an axle rod. The roller  20  is made of a less hard, more pliable material that is quieter and more energy-absorbing. Voids  40  extend through the roller  20  between the periphery  28  and the bore  32  from the first side  30  to the axially opposite second side  31 . In this version the voids  40  extend parallel to the axis of rotation  24  and form channels that open onto the first and second sides  30 ,  31  of the roller  20 . The voids  40  are shown regularly spaced circumferentially around the roller  20 . And the voids  40  have a teardrop-shaped cross section that has a narrow end  42  nearer the bore  32  of the roller  20  tapering out to a wide end  43  nearer the periphery  28 . Each of the voids  40  has an axis of symmetry  44  that does not intersect the axis of rotation  24 . In this version the voids  40  extend across the width of the roller  20  parallel to the axis of rotation  24 . The voids  40  allow the roller  20  to elastically deform slightly and absorb impacts with conveyed articles. By absorbing the impacts, the rollers  20  damp the motion of the articles as they strike and prevent bouncing and reorientation. 
         [0012]    The roller columns  18  are shown in more detail in  FIGS. 4A and 4B . The rollers  20  are stacked on a rod  46  that extends through the bushings  34  in the roller bores. The sleeves  38  of the bushings  34  sit on the larger-diameter flanges  36  of adjacent bushings in the column  18 . The sleeves  38  are longer than the width of the rollers  20  and serve with the flanges  36  as spacers to provide a gap  48  between adjacent rollers  20  large enough to accommodate the interleaved rollers of an adjacent column  18 ,  19  as in  FIG. 1 . If the rollers of adjacent columns are not interleaved, bushings with shorter sleeves can be used. The ends  50 ,  51  of the rod  46  are retained in the top and bottom rails  22 ,  23  shown in  FIG. 1 . 
         [0013]    Although the invention has been described in reference to an exemplary version, other versions are possible. For example, instead of having bushings, the rollers could be molded or machined as a single piece of material with an integral central hub that extends outward from one or both sides to space stacked rollers. As another example, the guide wall can be positioned within a stream of articles, rather than alongside as in  FIG. 1 , to help corral, guide, or separate the flow of articles. Or it could be used as a stop across a conveyor to divert intercepted articles to one side. So, as these few examples suggest, the scope of the claims is not meant to be limited to the details of the exemplary versions used to describe the invention.