Abstract:
A cleanable shoe-type diverter belt having narrow translatable pushers forming article-diverting shoes covering little or none of the belt&#39;s conveying surface. Cam followers on the shoes below the pushers follow selectively actuated or fixed guides under the belt to translate the shoes along a transverse track across the width of the belt. Cam followers of different lengths are programmed to follow different paths by multi-level guides.

Description:
BACKGROUND 
       [0001]    The invention relates generally to power-driven conveyors and more particularly to shoe-type diverters. 
         [0002]    Article diverters, such as shoe sorters, are used to translate articles across the width of a conveyor as the conveyor transports the articles in a conveying direction. Typical shoe sorters include article-pushing elements referred to as shoes that are driven laterally across the conveyor to push articles off one or both sides of the conveyor to one or more outfeed locations. Slat conveyors and modular conveyor belts are used as the platform for the shoes, which ride in tracks extending across the widths of the slats or belt modules. The shoes are conventionally blocked-shaped with depending structural elements that keep the shoe in the track or extend below to engage carryway guides that control the positions of the shoes. Although shoe sorters and other diverters are widely used in package-handling applications, they are not so useful in food-handling and other applications where sanitation is important because they are not easy to clean. Thus, there is a need for cleanable shoe-type diverters. 
       SUMMARY 
       [0003]    This need is addressed by diverting conveyors and conveyor belts embodying features of the invention. One example of an article-diverting conveyor belt comprises a plurality of belt modules. Each module extends in length from a trailing end to a leading end in a conveying direction and in width from a left side to a right side. The belt modules are arranged end to end. At least some of the belt modules include an intermediate portion that extends in length from the leading end to the trailing end and in width from the left side to the right side. The intermediate portion has a top side and an opposite bottom side. An elongated slot is formed in the intermediate portion from the top side to the bottom side. The slot extends across a majority of the width of the intermediate portion. A monolithic pusher is movably retained in the intermediate portion to move along the elongated slot. The pusher has an article-engaging upper portion above the top side of the intermediate portion and a lower cam portion below the bottom side of the intermediate portion. 
         [0004]    Another version of an article-diverting conveyor belt comprises belt modules, each of which extends in length from a trailing end to a leading end in a conveying direction and in width from a left side to a right side. The belt modules are arranged end to end. At least some of the belt modules include an intermediate portion extending in length from the leading end to the trailing end and in width from the left side to the right side and with a top side and an opposite bottom side. An elongated slot formed in the intermediate portion from the top side to the bottom side extends across a majority of the width of the intermediate portion. A pusher extends through the elongated slot. The pusher includes a narrow article-engaging portion above the intermediate portion and a lower portion below the intermediate portion. The outer dimensions of the pusher just above the top side and just below the bottom side of the intermediate portion are slightly greater than the width of the slot to retain the pusher in the slot. 
         [0005]    Another version of an article-diverting conveyor belt comprises a top side and an opposite bottom side. Parallel tracks extend transversely across a majority of the width of the conveyor belt. Pushers are arranged to ride along the tracks. The pushers include upper article-engaging portions above the top side of the conveyor belt and cam followers below the bottom side for contact with guides below the conveyor belt. The cam followers of some of the pushers extend below the bottom side a first distance, and the cam followers of other of the pushers extend below the bottom side a greater second distance. 
         [0006]    In another aspect of the invention, an article-diverting conveyor comprises a conveyor belt having a plurality of pushers arranged to translate transversely across the width of the conveyor belt along spaced apart paths. The pushers include cam followers extending below the conveyor belt. A retractable guide disposed below the conveyor belt has a guide surface that is selectively movable between a first position in contact with the cam followers to translate the pushers across the conveyor belt and a second position not in contact with the cam followers to avoid translating the pushers. 
         [0007]    Another version of a diverting conveyor comprises a conveyor belt advancing in a direction of belt travel. The belt has pushers arranged to translate transversely across the width of the conveyor belt along paths regularly spaced apart a distance defining a pusher pitch. The pushers include cam followers that extending below the conveyor belt. A cam wheel disposed below the conveyor belt rotates on an axis perpendicular to the plane of the conveyor belt. The cam wheel includes lobes regularly spaced around its periphery to match the pusher pitch. Some of the lobes are cam paddles that receive a driving force from the cam followers to rotate the cam wheel. At least one of the lobes is a diverting cam having a leading edge that extends radially outward farther than the cam paddles to engage the cam follower of a pusher. The diverting cam translates the pusher while the cam follower of the next pusher forward is pushing on one of the cam paddles to rotate the cam wheel as the conveyor belt advances. 
         [0008]    Yet another version of a diverting conveyor comprises a conveyor belt having a plurality of pushers arranged to translate transversely across the width of the conveyor belt along spaced apart paths. Some of the pushers include cam followers that extend below the conveyor belt a first distance; other of the pushers include cam followers that extend below the conveyor belt a greater second distance. A guide disposed below the conveyor belt has first guide surfaces at a first level for engaging the cam followers of the first and second plurality of pushers to translate their pushers and second guides at a second level below the first level and below the cam followers of the first plurality of pushers and not below the cam followers of the second plurality of pushers to translate the second plurality of pushers and not the first plurality of pushers. 
         [0009]    Another version of a diverter comprises conveyor modules that extend in length from a trailing end to a leading end in a conveying direction and in width from a left side to a right side. The modules are arranged end to end. At least some of the modules include a deck that extends in length from the leading end to the trailing end and in width from the left side to the right side. The deck has a top side and an opposite bottom side. An elongated slot is formed in the deck from the top side to the bottom side. The slot extends across the majority of the module&#39;s width. A bar extends along the width of the module below the top side of the deck. A pusher has opposite first and second ends and a through hole disposed between the ends. The pusher extends through the elongated slot with a first portion including its first end above the deck and a second portion including its second end below the deck. The bar extends through the through hole in the pusher to retain the pusher on the bar as the pusher translates across the width of the conveyor module along the elongated slot. A guide coupled to the pushers translates the pushers along the slots. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    These features of the invention, as well as other aspects and advantages, are described in more detail in the following description, appended claims, and accompanying drawings, in which: 
           [0011]      FIG. 1  is an isometric view of a portion of a diverter belt embodying features of the invention; 
           [0012]      FIG. 2  is a front elevation view of the belt portion of  FIG. 1 ; 
           [0013]      FIG. 3  is a plan schematic of a sorter using a belt as in  FIG. 1 ; 
           [0014]      FIG. 4  is an enlarged cross section of the conveyor belt of  FIG. 2  viewed along line  4 - 4 ; 
           [0015]      FIGS. 5A and 5B  are axonometric views of a module usable in a diverter belt as in  FIG. 1  with a slotted, retractable pusher in extended and retracted positions; 
           [0016]      FIG. 6  is an axonometric view of a module usable in a diverter belt as in  FIG. 1  with a pusher having a parallelepiped-shaped article-contacting portion above the deck; 
           [0017]      FIGS. 7A-7D  are front views of another version of a belt module embodying features of the invention; 
           [0018]      FIGS. 8A and 8B  are side and front elevation views of a pusher used in a conveyor belt module as in  FIGS. 7A-7D , and  FIGS. 8C and 8D  are side and front elevation views of a pusher as in  FIGS. 8A and 8B  with wings; 
           [0019]      FIG. 9  is an isometric view of a portion of a conveyor belt constructed of modules as in  FIGS. 7A-7D ; 
           [0020]      FIG. 10  is a side elevation view of the conveyor belt of  FIG. 9 ; 
           [0021]      FIG. 11  is a side elevation view of a conveyor belt as in  FIG. 9 , but having cam followers of different heights on the pushers; 
           [0022]      FIG. 12  is an axonometric view of one version of a guide mechanism usable with a conveyor belt as in  FIG. 11 ; 
           [0023]      FIG. 13  is an isometric view of a terraced guide mechanism usable with a conveyor belt as in  FIG. 11 ; 
           [0024]      FIG. 14  is an isometric view of a portion of a carryway with fixed guide mechanisms and a retractable guide mechanism for guiding the pushers of a conveyor belt as in  FIG. 10 ; 
           [0025]      FIG. 15A  is an isometric view of another version of a retractable guide mechanism usable with a conveyor belt as in  FIG. 10 , and  FIGS. 15B and 15C  are side elevation views of the retractable guide mechanism in retracted and unretracted positions; 
           [0026]      FIGS. 16A-16D  are top plan views illustrating the sequential operation of a rotatable cam-actuated guide mechanism usable with a conveyor belt as in  FIG. 10 ; 
           [0027]      FIG. 17  is a top plan view of the conveyor belt of  FIG. 10  with the pushers controlled by the guide mechanism of  FIGS. 16A-16D ; 
           [0028]      FIG. 18  is an isometric view of a peg-diverter belt as in  FIG. 1  or  FIG. 10  used in an infeed balance application; 
           [0029]      FIG. 19  is an isometric view of a peg-diverter belt used in a switch application; 
           [0030]      FIG. 20  is an isometric view of a peg-diverter belt used in a simple alignment application; 
           [0031]      FIG. 21  is an isometric view of a peg-diverter belt used in a timed-infeed merge application; 
           [0032]      FIG. 22  is an isometric view of two peg-diverter belts used in a recirculating singulation application; 
           [0033]      FIG. 23  is an isometric view of three peg-diverter belts used in a size-sorting-with-rejection application; 
           [0034]      FIG. 24  is an isometric view of a peg-diverter belt used in a simple merge application; 
           [0035]      FIG. 25  is an isometric view of a peg-diverter belt used in a sorting application; 
           [0036]      FIG. 26  is an isometric view of a peg-diverter belt used in a two-lane sorting application; and 
           [0037]      FIG. 27  is an isometric view of a peg-diverter belt illustrating multiple consecutive peg pushers translated in parallel to maintain article orientation during diversion. 
       
    
    
     DETAILED DESCRIPTION 
       [0038]      FIGS. 1 and 2  show a portion of the conveyor belt usable as an article diverter embodying features of the invention. The conveyor belt  10  is constructed of a series of conveyor belt modules  12  arranged in rows  14 . Each conveyor module  12  extends in length from a trailing end  16  to a leading end  17  in a conveying direction  18 , i.e., a direction of belt travel. The modules  12  extend in width from a left side  20  to a right side  21 . The module has an intermediate portion, in the form of a central deck  22 , and hinge elements  24  spaced apart along the trailing and leading ends  16 ,  17  of the module  12 . The hinge elements  24  are interconnected, by hinge pins, for example, at hinge joints  26  between adjacent rows  14 . Instead of a modular hinged belt, a slat conveyor belt constructed of slat modules between flanking roller chains could be used. 
         [0039]    An elongated slot  28  extends through the deck  22  from a top conveying side  30  to an opposite bottom side  31  and across the majority of the width of the module midway between its two ends  16 ,  17 . A pusher  32 , in the form of a peg, is received in the slot  28 , as also shown in  FIG. 4 . The pusher extends from a bottom end  34  to an opposite top end  35 . A through hole  36  is disposed in the pusher between its two opposite ends  34 ,  35 . The pusher in this example is realized as a monolithic element homogeneously formed as a single piece by molding, for example. A transverse bar  38  extending across the width of the module below the deck  22  is connected to the underside of the module near the left and right sides  20 ,  21  by webs  40 , as shown in  FIG. 2 . The bar is received in the pusher&#39;s through hole  36 . The bar  38 , which is parallel to the slot  28 , retains the pusher  32  and allows it to translate along the slot. The bar may also serve as a drive bar engaged by drive and idle sprockets in a positively driven conveyor system. The upper portion  42  of the pusher  32  between the pusher&#39;s top end  35  and the top side  30  of the deck  22  is used like a shoe to push articles  44  transversely across the module  12  toward either side. 
         [0040]    A guide mechanism  46  underlies the belt  10  along an upper carryway  48 , as shown in  FIGS. 2 and 3 , and, along with the belt, forms a diverting conveyor  50 , such as a sorter. The guide mechanism  46  shown schematically in  FIG. 3  is a conventional system of mechanical guides  52 ,  53  in the carryway  48  having vertical surfaces that engage the bottom ends  34  of the pushers  32  to divert the pushers across the belt. The bottom ends, acting like keels or cam followers, follow the guides as the belt  12  advances in the conveying direction  18 . As shown in  FIG. 3 , the peg pushers  32  in each module translate as guided by the upstream guide  52 . In this example, the article  44 , such as a tray, is pushed toward and off the right side  21  of the belt by the pushers to an outfeed conveyor  54  disposed at a specific location along the conveyor. After passing the downstream end  56  of the upstream guide  53 , the pushers remain in their transverse position until they reach the downstream return guide  53 , which guides the pushers back to the left side  20  of the belt. Of course, many different diverters with multiple outfeed conveyors on both sides and associated guide arrangements can be used besides the one in  FIG. 3 , which is used as a simple example to describe the operation of a sorter. Furthermore, different guide mechanisms may be used. For example, the pusher can include a magnetic material such as magnetic or ferrous particles or a magnetic or magnetically attractive element ( 58 ,  FIG. 4 ), such as a magnet or a piece of iron. The guide mechanism would then include magnetic guides or an electromagnetic array to translate the pushers across the belt. 
         [0041]    Another version of the pusher is shown in the module  12  of  FIGS. 5A and 5B . The pusher  32 ′ has a vertically elongated, slot-like through hole  60  receiving the transverse bar  38 . The elongated through hole extends close to the top end  35  of the pusher  32 ′ and allows it to be retracted to a level below the top side  30  of the deck  22 . A horizontal cam surface  61  in the carryway is positioned high enough to force the bottom side  34  of the pusher  32 ′ upward toward the slot  28  to maintain the pusher in an extended position above the deck. When the horizontal cam surface is lowered or absent, the pusher  32 ′ falls into its retracted position below the top side of the deck. 
         [0042]    Yet another version of the pusher is shown in  FIG. 6 . The pusher  32 ″ has a parallelepiped-shaped article-contacting platform portion  62  that extends above the top side  30  of the deck  22  and a bottom cam-follower  64  like that for the pusher of  FIG. 1 . The maximum dimension of the article-contacting portion  62  in the conveying direction  18  is slightly less than the width of the slot  28  in the conveying direction so that the pusher  32 ″ does not overlap the top side  30  of the deck  22 . The height of the pusher  32 ″ could be even less than indicated in  FIG. 6  to form a platform  65  elevated slightly above the top side  30  to engage the bottoms of conveyed articles, lift them slightly, and carry them across the deck  22 . The pusher  32 ″ could include a vertical peg pushing portion  66  that forms an L shape with the horizontal article-contacting supporting platform portion  62 . 
         [0043]    Unlike conventional blocky shoes, the narrow pegs  32 ,  32 ′ of  FIGS. 1-5  and the narrow parallelepiped-shaped pushers  32 ″ of  FIG. 6  do not overlap and occlude any portion of the deck  22 —top or bottom. That makes the top side  30  of the belt accessible and easy to clean. 
         [0044]    Another version of a conveyor belt module with a peg pusher is shown in  FIGS. 7A-7D . The belt module  70  is similar to the module  12  of  FIG. 5A , but differs in that it has an elongated slot  72  that is longitudinally offset from its central drive bar  73 . In other words, the slot is closer to a first end  74  of the module than to its opposite second end  75 . A peg pusher  76  is slidably retained in the slot  72 . The pusher  76  has an upper portion  78  and a lower cam-follower portion  80  joined by an intermediate shank portion  82 , as shown in  FIGS. 8A and 8B . The pusher in this example is realized as a monolithic element homogeneously formed as a single piece by molding, for example. The upper portion is pawn-shaped and flares outward toward the bottom to form a skirt  84  that slides along the top conveying surface  86  of the belt module  70 . The narrow shank  82  resides in the slot  72 . The lower portion  80  has an upper shoulder  88  that slides along the bottom surface  87  of the module. The height of the shank  82  is slightly greater than the thickness of the module  70  at the slot. The height of the shoulder portion  88  is slightly greater than the height of the drive bar  73  so that the cam follower  80  is below the bottom of the drive bar. The outer dimensions of the pusher slightly above the top conveying side  86  and slightly below the bottom side  87  of the intermediate portion are slightly greater than the width of the slot—enough to retain the pusher in the slot. The narrow portion  90  of the deck  91  of the plastic module between the slot  72  and the first end  74  and shown hatched in  FIG. 7C  is flexed upward or downward to temporarily widen the slot to admit the pusher into place. Once the pusher is in place the narrow portion  90  is released, and the module  70  returns to its natural state retaining the pusher  76 . Alternatively, the slot  72  could have a wider access opening  89  at one end that is large enough in diameter to admit the pusher  76  into the slot. The placement of guides under the belt would confine the pusher to the narrow main portion of the slot. 
         [0045]    The pusher of  FIGS. 8A and 8B  is outfitted with wings  81  in  FIGS. 8C and 8D  to form a pusher  83  better suited to pushing non-rigid articles, such as bags. The wings extend from opposite sides of a central peg  85  parallel to the conveying direction when installed in a conveyor belt. Together the wings  81  form a vertical plate for pushing articles across the belt. 
         [0046]    A portion of the conveyor belt  92  constructed of rows  94  of the belt modules  70  is shown in  FIGS. 9 and 10 . The rows are joined by hinge rods  95  received in the aligned openings  96  of interleaved hinge elements  98  of adjacent rows. Instead of having pusher modules  70  in each row, the belt  92  could have pusher modules interspersed with pusherless and slotless standard modules. 
         [0047]    As shown in the side view of  FIG. 10 , all the lower cam-follower portions  80  of the pushers  76  extend below the belt the same distance to the same depth. In another version, a conveyor belt  92 ′, shown in  FIG. 11 , has lower cam-follower portions  80 ,  80 ′,  80 ″ on the pushers  76 ,  76 ′,  76 ″ that extend downward different distances to different depths. When used with a guide  100 ,  100 ′ as in  FIG. 12  or  FIG. 13 , the pushers  76 ,  76 ′,  76 ″ can be guided differently. The guide  100  of  FIG. 2  is mounted in the conveyor carryway under the conveyor belt. The guide  100  has a deep channel  102  that veers to the right. A shallow channel  103  branches off from the deep channel, but in line with its upstream portion. The pushers  76 ″ having the deepest cam followers  80 ″ encounter a guide surface in the form of a ledge  104  at the branch of the deep and shallow channels  102 ,  103 . The ledge guides the pushers  76 ″ across the belt. The pushers  76 ,  76 ′ having shallower cam followers  80 ,  80 ′ clear the ledge  104  and maintain their lateral positions on the belt. The side walls of the channels  102 ,  103  form guides for the pushers. 
         [0048]    Another version of a diverting guide  100 ′ underlying the conveyor belt in the carryway is shown in  FIG. 13 . This guide has three levels, or terraces  106 ,  106 ′,  106 ″, at three different depths. Ledges  108 ,  108 ′, and  108 ″ serve as guide surfaces for the pushers. The ledge  108  is between the top terrace  106  and the intermediate terrace  106 ′. The ledge  108 ′ is between the intermediate terrace  106 ′ and the bottom terrace  106 ″. The ledge  108 ′ forms the outer edge of the bottom terrace  106 ″. The pushers  76 ″ with the deepest cam followers  80 ″ are guided across the belt by the bottom ledge  108 ″. The intermediate and shallow cam followers  80 ′,  80  clear the bottom ledge. The pusher  76 ′ with the intermediate cam follower  80 ′ is guided by the intermediate ledge  108 ′, and the shallow cam follower  80  by the shallow ledge  108 . In this way, the terraced guide  100 ′ can translate the pushers  76 ,  76 ′,  76 ″ to different lateral positions across the width of the conveyor belt  92 ′. 
         [0049]      FIG. 14  shows two rows of a conveyor belt  110  advancing along a carryway in a direction of belt travel  112 . A guide mechanism  114  is held in place under the conveyor belt by a pair of frame members  116 ,  117 . The guide mechanism comprises a funnel-like upstream guide  118  with a curved guide wall  120  that guides all the cam followers and the pushers  76  to the left side of the belt. The top surfaces of islands  122 ,  123  provide support to the bottom surface of the belt  110 . A selectively retractable diverting guide  124  has a diverter wall  126  with a curved input hook  128  that guides the pushers  76  to the right side of the belt when the guide is in a raised diverting position, as shown in  FIG. 14 . The guide is pivotably attached to the right-side frame member  116  by a hinge  130  that allows the guide to pivot about its pivot axis  132  downward to a retracted position, in which the pushers are not diverted. An actuator (not shown in the drawings), such as an air or hydraulic cylinder, a motor and gears, a solenoid, or other actuating device, is used to pivot the guide  124  between the retracted (non-diverting) position and the unretracted (diverting) position. The actuator can be controlled by a controller that receives sensor signals indicating an article&#39;s passing a certain location along the carryway and times the actuation of the actuator accordingly. A return funnel  134 , identical to the input funnel in this example, guides the pusher  76  back to the left side of the conveyor belt.  FIGS. 15A and 15B  show the guide  124  in the retracted (non-diverting) position, allowing the pusher  76  to pass through without diverting. In  FIG. 15C , the guide  124  is shown in an unretracted (diverting) position. The hook portion  128  of the guide wall  126  intercepts the cam follower  80  of the pusher  76  and guides it across the belt to the right-hand side as indicated by arrow  130 . In this example, the guide is swiveled about a hinge by an actuator (not shown), such as a linear actuator or a motor-driven rotating hinge. But the guide can be selectively retracted in other conventional ways. For example, the entire guide could be translated up into an upper diverting position and down into a lower non-diverting position by a conventional linear actuator. 
         [0050]      FIGS. 16 and 17  show a cam-wheel guide mechanism for registering and metering conveyed articles. The cam wheel  132  in this example has five lobes: (a) four identical cam paddles  134  and (b) one diverting cam  136  equally spaced around the wheel&#39;s periphery. The circumferential spacing of the paddles and the diverting cam match the linear spacing, or pitch, of the slots  72  and the pushers  76 . The cam wheel  132  is passive and pivots about a central pivot pin  138  defining an axis perpendicular to the plane of the conveyor belt  92 . As the conveyor belt  92  advances in the direction of belt travel  112 , the cam followers below the belt on the pushers  76  contact the paddles  134  to rotate the wheel through one-fifth of a complete rotation (72°) without changing the position of the pushers on the track  72 , as shown in  FIG. 16A . When the leading edge  140  of the diverting cam  136  contacts a pusher  76 ′, it forces that pusher along the track, as shown in  FIGS. 16B and 16C . The next pusher then engages a rear edge  142  of the diverter cam to rotate the cam another 72°, as shown in  FIG. 16D . With the cam wheel  132  of  FIG. 16A-D  mounted in a housing  144  under a side edge of the conveyor belt  92 , as in  FIG. 17 , every fifth pusher  76 ′ is positioned away from the reset position of the other pushers  76 . The four consecutive pushers  76  at the reset position serve to register all the conveyed articles  146  at the same lateral position across the width of the belt. The offset fifth pushers  76 ′ meter the articles at equally spaced locations along the length of the belt. Cam wheels with different geometries can be used to achieve different effects. 
         [0051]      FIGS. 18-27  depict various conveyor configurations using a pusher-belt diverter as in  FIGS. 1-15  in different conveying applications. 
         [0052]      FIG. 18  shows an infeed-balance configuration. Two infeed conveyors  150 ,  151  feed articles  146  in two lanes onto a conveyor belt  145  having two pushers  147 ,  147 ′ (a right-side pusher  147  and a left-side pusher  147 ′) in each slot  72 . The pushers are arranged to have a left-side row of pushers and a right-side row of pushers as the belt  145  enters the infeed end of the carryway. The left-side pushers  147 ′ remain in the reset position as indicated by arrow  152 . The right-side pushers are guided to divert the articles on the right-side infeed conveyor  151  to the left, as indicated by arrow  153 , aligned with the articles from the left-side infeed conveyor  150 . A fixed, non-retractable guide can be used for the divert. A downstream guide, indicated by arrow  154 , selectively guides left-side pushers  147 ′ across the belt or leaves them in place to divert articles to the right or allow them to continue straight through along the left side. The right-side pushers  147  may optionally be guided by a fixed guide to align the diverted articles along the right side of the conveyor. In this way, the imbalances in the flow between the two infeed conveyors can be balanced upon exit from the pusher-belt diverter. In the example of  FIG. 18  and all the following examples, the arrows indicate the geometry of the guides and the diversion paths of the pushers. 
         [0053]      FIG. 19  shows a switch configuration in which articles supplied by a single infeed conveyor  156  are switched from a single lane into two output lanes on an outfeed conveyor  158 . The pusher-belt diverter selectively passes an article from the single file straight through (arrow  160 ) along the left side or diverts to the right side (arrow  161 ) of the pusher belt  145  to form the two lanes of articles. 
         [0054]    Simple alignment of a stream of articles is achieved with the conveyor configuration of  FIG. 20 . Articles  146  on an infeed conveyor  162  are pivoted by a bumper  164  as they enter the pusher belt  145 . A guide diverts the incoming articles, as indicated by arrow  166 , and aligns them on the belt in line with an outfeed conveyor  168 . A fixed, non-retractable guide can be used in this configuration. 
         [0055]    A three-to-one merge-conveyor configuration is shown in  FIG. 21 . Three parallel infeed conveyor belts  170  with registration flights  172  meter and deliver articles  146  to the pusher belt  145  one at a time from each infeed belt in round-robin fashion. A guide guides the pushers  147  from outside positions to inner positions to plow the articles into a single file aligned with an outfeed conveyor  174  as indicated by arrows  176 ,  177 . Fixed guides can be used to guide the pushers  147 . 
         [0056]      FIG. 22  depicts a singulator with recirculation to prevent articles from exiting side by side. An infeed conveyor  178  is shown delivering articles  146  two abreast to the pusher belt  145 . The pushers  147  are guided to plow the articles toward one side to form a single file aligned with an outfeed conveyor  180 , as indicated by arrow  182 . Side-by-sides  146 ′ are pushed off the side of the pusher belt  145  onto a recirculation pusher belt  145 ′ running in the opposite direction. The guide for the recirculation belt  145 ′ positions its pushers  147 ′ to direct the recirculated articles  146 ′ back onto the first pusher belt  145  to be singulated. Fixed guides can be used to position the pushers  147 . 
         [0057]    The conveyor configuration of  FIG. 23  can sort articles of different sizes and selectively reject articles. An infeed conveyor  184  delivers small  146  and large  146 ′ articles to a pusher-belt diverter  186  that sorts the articles by size. A size sensor  188  sends a signal to a guide under the belt to selectively divert large articles to a left-side pusher-belt diverter  190  and small articles to a right-side pusher-belt diverter  192  as indicated by arrow  194 . Like the size sensor, quality sensors  196 ,  197  send signals indicative of product quality to the associated guide mechanisms for each quality diverter  190 ,  192  to selectively divert rejected articles  146 X and  146 X′, as indicated by arrows  198 ,  199 . 
         [0058]    The simple merge conveyor of  FIG. 24  uses a pusher-belt diverter  200  with a fixed diverter guide, whose operation is indicated by arrow  202 , to merge two lanes of articles from two side-by-side infeed conveyors  204 ,  205  feeding articles one at a time to the pusher-belt diverter. The merged articles are delivered single file to a downstream outfeed conveyor  206 . 
         [0059]    In the sorter shown in  FIG. 25 , articles  146  on a pusher-belt diverter  208  are diverted by selectively actuated guides underlying the peg belt  145  at sequential locations indicated by arrows  210 ,  211 ,  212 . When a guide is actuated, it directs the pushers  147  to push the articles off the side of the pusher-belt diverter onto an associated one of the sorting conveyors  214 ,  215 ,  216 . If none of the guides is actuated for an article, the article continues to advance off the end of the pusher belt  145 , as indicated by the arrow  218 . The pusher-belt diverter can also be operated as a two-lane sorter as shown in  FIG. 26  to sort articles off either side of the diverter  220  to multiple sorting conveyors. 
         [0060]    The pusher-belt diverter  222  of  FIG. 27  diverts articles from one lane to another without changing the articles&#39; orientations. The guide has three parallel guide walls as indicated by the three paths in the arrow diagram  224 . The three paths are spaced apart from each other by the spacing, or pitch, of the pushers  147  and their slots  148 . With this configuration, three pushers are translated across the belt  145  simultaneously, which translates an article more or less centered on the three pushers from the left lane to the right lane without pivoting. If the guide is not actuated, the pushers remain in their reset position to maintain an article in the left lane.