Vertical mail piece stacker

Abstract

A mail piece stacker system includes a back wall and a side wall. A platform is mounted adjacent to the back wall and side wall and is moveable in a vertical direction. The platform is adapted to support a stack of mail pieces, such as mail pieces, and has means connected to the platform to position the platform in a first vertical position when no mail pieces are on the platform and to position the platform in a different vertical position lower than the first vertical position when mail pieces are on the platform. The platform may be positioned at an acute angle with respect to the back wall and the side wall to help in registering mail pieces being stacked on the platform. The stacker may employ the method of moving mail pieces seriatim onto a platform. The platform is moveable in a vertical direction and is moved in a downward direction as mail pieces are stacked on the platform. The movement is such that the vertical level of the stacker platform is adjusted as mail pieces are stacked on the platform so that the top surface of the topmost mail piece is substantially adjacent the vertical position of the platform when no mail pieces are on the platform.

1 . A stacker system, comprising: 
 a back wall and a side wall;    a platform adapted to support a stack of mail pieces, said platform mounted adjacent said back wall, and said side wall, said platform moveable in a vertical direction; and,    a means connected to said platform to position said platform in a first vertical position when no mail pieces are on said platform and to position said platform in a different vertical position lower than the first vertical position when mail pieces are on said platform.    
   
   
       2 . A stacker system as defined in  claim 1 , wherein said platform is positioned with respect to said back wall to form an acute angle such that mail pieces on said platform tend to move toward said back wall.  
   
   
       3 . A stacker system as defined in  claim 2 , wherein said platform is positioned with respect to said side wall to form an acute angle such that mail pieces on said platform tend to move toward said sidewall.  
   
   
       4 . A stacker system as defined in  claim 1 , wherein said platform is positioned with respect to said back wall to form an acute angle and said platform is positioned with respect to said sidewall to form an acute angle such that mail pieces on said platform tend to move toward said back wall and tend to move toward said side wall.  
   
   
       5 . A stacker system as defined in  claim 4 , including guide members for guiding mail pieces onto the platform.  
   
   
       6 . A stacker system as defined in  claim 5 , wherein said first vertical position of said platform is at a height to receive mail pieces moved past the guide members and onto said platform.  
   
   
       7 . A stacker system as defined in  claim 1 , wherein said means is a spring selected such that vertical downward movement of said platform under the weight of a mail piece is a distance substantially equal to the thickness of said mail piece so that the topmost mail piece of a stack of mail pieces on said platform is substantially adjacent to said first vertical position.  
   
   
       8 . A stacker system as defined in  claim 7 , wherein said platform is positioned with respect to said back wall to form an acute angle such that mail pieces on said platform tend to move toward said back wall.  
   
   
       9 . A stacker system as defined in  claim 7 , wherein said platform is positioned with respect to said side wall to form an acute angle such that mail pieces on said platform tend to move toward said sidewall.  
   
   
       10 . A stacker system as defined in  claim 7 , wherein said platform is positioned with respect to said back wall to form an acute angle and said platform is positioned with said sidewall to form an acute angle such that mail pieces on said platform tend to move toward said back wall and tend to move toward said side wall.  
   
   
       11 . A stacker system as defined in  claim 1 , wherein said platform is mounted to a moveable belt.  
   
   
       12 . A stacker system as defined in  claim 11 , wherein said platform includes a first platform segment and a second platform segment.  
   
   
       13 . A stacking system as defined in  claim 12 , wherein said means is a motor connected to said moveable belt.  
   
   
       14 . A stacker system as defined in  claim 1 , further comprising a lock mechanism for locking said platform from vertical movement.  
   
   
       15 . A stacker system as defined in  claim 14 , further comprising a pivot connected to enable said platform to be moved for unloading a stack of mail pieces on said platform into a mailing tray.  
   
   
       16 . A stacker system as defined in  claim 7 , wherein said spring is tunable to accommodate different size mail pieces.  
   
   
       17 . A method for stacking mail pieces, comprising the steps of: 
 moving mail pieces seriatim onto a vertically moveable platform; and,    adjusting the vertical level of said platform such that said topmost mail piece surface remains substantially adjacent the vertical position of said platform without mail pieces on said platform.    
   
   
       18 . A method for stacking media items as defined in  claim 17 , wherein said vertically moveable platform is adjacent a back wall and moving said mail pieces includes the step of moving a lead edge of each of said mail pieces to strike said back wall and thereafter move downward toward said platform.  
   
   
       19 . A method for stacking mail pieces as defined in  claim 18 , wherein said vertically moveable platform is adjacent a side wall and moving said mail pieces includes the step of moving said mail pieces toward said side wall.