Sheet separator in a loading system and method for separating sheets during loading

Abstract

According to some embodiments of the invention, a method for separating sheets is provided. The method comprises positioning onto a stack of sheets grippers having suction cups attached to vertical rods, then applying vacuum to the suction cups, and while maintaining the vacuum, raising the rods to lift one or more of sheets and then vertically moving the rods up and down according to a predefined motion scheme.

What is claimed is:  
     
         1 . A sheet separator comprising: 
 two or more vertical grippers each having a suction cup;    two or more movement units, each of said movement units to move vertically one or more of said grippers independently of at least one other of said grippers; and    a controller to activate independently said movement units.    
     
     
         2 . The separator of  claim 1 , wherein said movement units comprise pneumatic pistons.  
     
     
         3 . The separator of  claim 1 , wherein said movement units comprise electrical motors.  
     
     
         4 . The separator of  claim 1 , wherein said movement units comprise mechanical gears.  
     
     
         5 . A sheet separator comprising: 
 two or more grippers comprising longitudinally movable piston rods and suction cups attached to said piston rods; and    a controller to instruct an energy source to move one or more of said piston rods independently of at least one other of said piston rods.    
     
     
         6 . The separator of  claim 5 , wherein said energy source comprises an air pressure unit.  
     
     
         7 . A method comprising: 
 positioning onto a stack of sheets a plurality of suction cups each attached to one of a corresponding plurality of vertical rods;    applying vacuum to said suction cups; and    while maintaining said vacuum, raising said rods to lift one or more of said sheets and then vertically moving said rods up and down according to a predefined motion scheme.    
     
     
         8 . The method of  claim 7 , wherein vertically moving said rods up and down according to said predefined motion scheme comprises vertically moving said rods up and down according to a predefined frequency and amplitude.  
     
     
         9 . The method of  claim 7 , wherein vertically moving said rods comprises moving said rods substantially simultaneously in the same direction.  
     
     
         10 . The method of  claim 7 , wherein vertically moving said rods comprises moving at least one of the rods substantially simultaneously in an opposite direction to at least one other of said rods.  
     
     
         11 . A method comprising: 
 positioning onto a stack of sheets a first and a second suction cups of a sheet separator;    applying vacuum to said suction cups;    while maintaining said vacuum, applying a vertical force on said stack via said first suction cup; and    substantially simultaneously, vertically moving upward said second suction cup.