Positive displacement sorter

Abstract

A positive displacement sorter apparatus includes a plurality of interconnected slats defining an endless web. An upper run of the web defines a conveying surface. Pusher shoes move along at least some of the slats to laterally displace an article on the conveying surface. The pusher shoes have slat engagement portions engaging the slats at shoe-engaging portions of the slats. Each of the pusher shoes has a body generally surrounding at least one of the slats. The body is substantially made of a first polymeric material. The slat engaging portions are substantially made of a second polymeric material that is different from the first polymeric material.

1 . A positive displacement sorter apparatus, comprising: 
 a plurality of interconnected slats defining an endless web, an upper run of said web defining a conveying surface;    pusher shoes moving along at least some of said plurality of slats to laterally displace an article on said conveying surface, said pusher shoes having slat engagement portions engaging the slats at shoe engaging portions of the slats;    each of said pusher shoes having a body generally surrounding at least one of said slats, said body substantially made of a first polymeric material, wherein said slat engaging portions substantially made of a second polymeric material that is different from said first polymeric material.    
   
   
       2 . The positive displacement sorter apparatus of  claim 1  wherein said first polymeric material has greater structural strength than said first polymeric material.  
   
   
       3 . The positive displacement sorter apparatus of  claim 1  wherein said shoe and slat engaging portions define a lateral stabilizer for resisting rotation of the associated one of said shoes about a vertical axis.  
   
   
       4 . The positive displacement sorter apparatus of  claim 3  wherein said lateral stabilizer comprises at least one of said slat engaging portions of said shoes protruding into at least one of said shoe engaging portions of said slats.  
   
   
       5 . The positive displacement sorter apparatus of  claim 4  wherein said slat engaging portions comprise inward projections from said body and wear strips that are supported by said projections, said strips made of said second polymeric material.  
   
   
       6 . The positive displacement sorter apparatus of  claim 4  wherein said slat engaging portions comprise inward projections from said body, said inward projections made of said second polymeric material.  
   
   
       7 . The positive displacement sorter apparatus of  claim 1  wherein said slat engaging portions comprise inward projections from said body and wear strips that are supported by said projections, said strips made of said second polymeric material.  
   
   
       8 . The positive displacement sorter apparatus of  claim 1  wherein said slat engaging portions comprise inward projections from said body, said inward projections made of said second polymeric material.  
   
   
       9 . The positive displacement sorter apparatus of  claim 1  wherein said first material is a generally lower cost material than said second material.  
   
   
       10 . The positive displacement sorter apparatus of  claim 1  wherein each of said pusher shoes further includes a diverting portion, said diverting portion adapted to contacting an article to be diverted.  
   
   
       11 . The positive displacement sorter apparatus of  claim 10  wherein said diverting portion defines at least one sloped surface, said at least one sloped surface being at an angle from the vehicle.  
   
   
       12 . A positive displacement sorter apparatus, comprising: 
 a plurality of interconnected slats defining an endless web, an upper run of said web defining a conveying surface;    pusher shoes moving along at least some of said plurality of slats to laterally displace an article on said conveying surface, said pusher shoes having slat engagement portions engaging the slats at shoe engaging portions of the slats;    each of said pusher shoes having a body generally surrounding at least one of said slats, said body substantially made of a first polymeric material, wherein said slat engaging portions substantially made of a second polymeric material that is different from said first polymeric material, said second polymeric material being self-lubricating.    
   
   
       13 . The positive displacement sorter apparatus of  claim 12  wherein said first polymeric material has greater structural strength than said first polymeric material.  
   
   
       14 . The positive displacement sorter apparatus of  claim 12  wherein said shoe and slat engaging portions define a lateral stabilizer for resisting rotation of the associated one of said shoes about a vertical axis.  
   
   
       15 . The positive displacement sorter apparatus of  claim 14  wherein said lateral stabilizer comprises at least one of said slat engaging portions of said shoes protruding into at least one of said shoe engaging portions of said slats.  
   
   
       16 . The positive displacement sorter apparatus of  claim 15  wherein said slat engaging portions comprise inward projections from said body and said wear strips that are supported by said projections, said strips made of said second polymeric material.  
   
   
       17 . The positive displacement sorter apparatus of  claim 15  wherein said slat engaging portions comprise inward projections from said body, said inward projections made of said second polymeric material.  
   
   
       18 . The positive displacement sorter apparatus of claims  12  wherein said slat engaging portions comprise inward projections from said body and wear strips that are supported by said projections, said strips made of said second polymeric material.  
   
   
       19 . The positive displacement sorter apparatus of  claim 12  wherein said slat engaging portions comprise inward projections from said body, said inward projections made of said second polymeric material.  
   
   
       20 . The positive displacement sorter apparatus of  claim 12  wherein said first material is a generally lower cost material than said second material.  
   
   
       21 . The positive displacement sorter apparatus of  claim 12  wherein each of said pusher shoes further includes a diverting portion, said diverting portion adapted to contacting articles to be diverted.  
   
   
       22 . The positive displacement sorter apparatus of  claim 21  wherein said diverting portion defines at least one sloped surface, said at least one sloped surface being at an angle from the vehicle.  
   
   
       23 . A positive displacement sorter apparatus, comprising: 
 a plurality of interconnected slats defining an endless web, an upper run of said web defining a conveying surface;    pusher shoes moving along at least some of said plurality of slats to laterally displace an article on said conveying surface, said pusher shoes having slat engagement portions engaging the slats at shoe engaging portions of the slats;    each of said pusher shoes having a body generally surrounding at least one of said slats, said body substantially made of a first polymeric material, projections extend inwardly from said body and strips supported by said projections, said strips substantially made of a second polymeric material that is different from said first polymeric material, said strips defining said slat engagement portions, said second polymeric material being self-lubricating.    
   
   
       24 . The positive displacement sorter apparatus of  claim 23  wherein said first polymeric material has greater structural strength than said first polymeric material.  
   
   
       25 . The positive displacement sorter apparatus of  claim 23  wherein said shoe and slat engaging portions define a lateral stabilizer for resisting rotation of the associated one of said shoes about a vertical axis.  
   
   
       26 . The positive displacement sorter apparatus of  claim 25  wherein said lateral stabilizer comprises at least one of said slat engaging portions of said shoes protruding into at least one of said shoe engaging portions of said slats.  
   
   
       27 . The positive displacement sorter apparatus of  claim 23  wherein said first material is a generally lower cost material than said second material.  
   
   
       28 . The positive displacement sorter apparatus of  claim 23  wherein each of said pusher shoes further includes a diverting portion, said diverting portion adapted to contacting articles to be diverted.  
   
   
       29 . The positive displacement sorter apparatus of  claim 28  wherein said diverting portion defines at least one sloped surface, said at least one sloped surface being at an angle from the vehicle.  
   
   
       30 . A positive displacement sorter pusher shoe for moving along at least one slat of a positive displacement sorter to laterally displace an article positioned on said at least one slat, said pusher shoe comprising: 
 a generally cylindrical body substantially made of a first polymeric material, projections extending inwardly from said body and strips supported by said projections, said strips substantially made of a second polymeric material that is different from said first polymeric material, said second polymeric material being self-lubricating.    
   
   
       31 . The positive displacement sorter pusher shoe of  claim 30  wherein said first polymeric material has greater structural strength than said first polymeric material.  
   
   
       32 . The positive displacement sorter pusher shoe of  claim 30  wherein said first material is a generally lower cost material than said second material.  
   
   
       33 . The positive displacement sorter pusher shoe of  claim 30  further including a diverting portion, said diverting portion adapted to contacting articles to be diverted.  
   
   
       34 . The positive displacement sorter pusher shoe of  claim 33  wherein said diverting portion defines at least one sloped surface, said at least one sloped surface being at an angle from the vehicle.