Method and device for aligning sheets in a transport module

Abstract

A transport module for deskewing and accumulating sheets of insert materials before the sheets are inserted into an envelope for mailing. Retractable gates are used to stop the sheets as they are separately moved into the transport module by a plurality of endless belts. Idlers are used to apply normal forces on the belts at various locations to provide traction between the sheet and the belts for moving the sheet forward. If a sheet is skewed when it enters the transport module, one corner on the leading edge of the sheet encounters one of the side gates and the advancing sheet can align itself by an angular motion using the contact point as center of rotation. As such, the leading edge is registered against the retractable gates at both sides of the leading edge. The transport module can also be used as a conveyor without the accumulation function.

1 . A method to transport mailing materials along a moving direction by a moving mechanism in a transport module for use in a mailing machine, the mailing materials including sheets to be accumulated, wherein each of the sheets is moved into the transport module along the moving direction, and the transport module comprises a registration barrier substantially perpendicular to the moving direction so as to allow a leading edge of each of the sheets to register against the registration barrier, the leading edge of each sheet has a first side and an opposing second side, the sheets including a current sheet and a previous sheet, the current sheet having a frictional force against the previous sheet, the transport module at least operable in a first mode to accumulate the sheets, said method comprising the steps of: 
 providing a moving surface on the moving mechanism adjacent to the current sheet; and    distributing a plurality of normal forces at a plurality of locations for urging the moving surface of the moving mechanism against the current sheet so as to produce a traction between the moving surface and the current sheet, such that, when the transport module is operated in the first mode, the traction is able to overcome the frictional force so as to continue moving the second side of the leading edge of the current sheet until it contacts the registration barrier, if the first side of the leading edge of the current sheet contacts the registration barrier before the second side.    
     
     
         2 . The method of  claim 1 , further comprising the step of: 
 retracting the registration barrier after the sheets have been accumulated so as to allow the accumulated sheets to move further along the moving direction.    
     
     
         3 . The method of  claim 1 , wherein the registration barrier is retractable and the mailing materials include mail items, and wherein the transport module is operable in a second mode, said method comprising the step of: 
 retracting the registration barrier when the transport module is operated in the second mode so as to allow the mail items to move further along the moving direction separately and sequentially.    
     
     
         4 . The method of  claim 1 , wherein the transport module is operable between the first mode and a second mode and the registration barrier is operable is a first position and a second position, and wherein the mailing materials also include mail items, said method further comprising the steps of: 
 maintaining the registration barrier in the first position when the transport module is operated in the first mode, such that if the first side of the leading edge of the current sheet contacts the registration barrier before the second side, the traction is able to overcome the frictional force so as to continue moving the second side of the leading edge of the current sheet until it contacts the registration barrier; and    retracting the registration barrier to the second position 
 after the sheets have been accumulated so as to allow the accumulated sheets to move further along the moving direction, and  
 when the transport module is operated in the second mode so as to allow the mail items to move further along the moving direction separately and sequentially.  
   
     
     
         5 . The method of  claim 1 , wherein the moving surface comprises a plurality of moving belts and the transport module comprises a plurality of weighting objects distributed at the plurality of locations for providing the normal forces to urge the moving belts against the current sheet.  
     
     
         6 . A transport module for use in a mailing machine to move and a plurality of mailing materials in a moving direction toward a downstream direction, the transport module at least operable in a first mode, wherein the mailing materials comprise sheets to be accumulated, the sheets having a current sheet and a previous sheet, the current sheet having a frictional force against the previous sheet, said transport module comprising: 
 a moving mechanism for moving each of the sheets along the moving direction, each sheet having a leading edge, the leading edge having a first side and an opposing second side, the moving mechanism having a moving surface adjacent to the current sheet;    a registration barrier operable in a first position and in a second position, the barrier substantially perpendicular to the moving direction so as to allow the leading edge of each of the sheets to register against the registration barrier when the transport module is operated in the first mode and the barrier is operated in the first position, and    a plurality of weighting objects distributed at a plurality of locations for urging the moving surface of the moving mechanism against the current sheet so as to produce a traction between the moving surface and the current sheet, such that if the first side of the leading edge of the current sheet contacts the registration barrier before the second side, the traction is able to overcome the frictional force so as to continue moving the second side of the leading edge until it contacts the registration barrier.    
     
     
         7 . The transport module of  claim 6 , wherein the registration barrier is retractable to the second position so as to allow the sheets to move toward the downstream direction after the sheets have been accumulated.  
     
     
         8 . The transport module of  claim 6 , wherein the mailing materials include mail items, and the transport module is also operable in a second mode so that, when the transport module is operated in the second mode, the registration barrier is retractable to the second position so as to allow the mail items to be moved toward the downstream direction separately and sequentially.  
     
     
         9 . The transport module of  claim 8 , wherein the mailing items include one or more cards.  
     
     
         10 . The transport module of  claim 8 , wherein the mailing items include one or more folded sheets.  
     
     
         11 . The transport module of  claim 12 , wherein the mailing items include one or more booklets.  
     
     
         12 . The transport module of  claim 7 , wherein the mailing materials include mail items, and the transport module is operable between the first mode and a second mode such that, 
 when the transport module is operated in the first mode, 
 the registration barrier is operated in the first position so as to allow the leading edge of each of the sheets to register against the registration barrier, and if the first side of the leading edge of the current sheet contacts the registration barrier before the second side, the traction is able to overcome the frictional force so as to continue moving the second side of the leading edge until it contacts the registration barrier; and  
 the registration barrier is retracted to the second position after the sheets have accumulated so as to allow the accumulated sheets to move further toward the downstream direction; and  
   when the transport module is operated in the second mode, 
 the registration barrier is retracted to the second position so as to allow the mail items to move separately and sequentially along the moving direction toward the downstream direction.