Stacker

Abstract

An apparatus for stacking a stream of moving sheet-like material such as, for example, mailpieces is described. The apparatus comprises a first moving belt positioned at a first level, the first belt adapted to receive the sheets lying in a first orientation and position the sheets downstream of the first belt; a second moving belt positioned at a level lower than the first belt and positioned whereby the sheets travel from an end position of the first belt down a step to the second belt; a first sensor positioned to sense break member in relation to the total thickness of the sheets on the first belt thereby causing an incremental movement of the first belt; a second sensor positioned in contiguous relation to the step and adapted to sense the sheet-like material as the sheets drop down the step to a second orientation thereby incrementally moving the sheet-like material according to the increased number of sheets on the second belt as they are stacked thereon in the second orientation; and a movable back stop member adapted to be locked onto the second belt, and further adapted to help support and stack the sheets in the second orientation, the stop member moving with the movement of the second belt.

What is claimed is:  
     
         1 . An apparatus for stacking a stream of moving sheet-like material comprising: 
 a first moving belt positioned at a first level, the first belt adapted to receive the sheet-like material lying in a first orientation and position the sheet-like material downstream of the first belt in an overlapped condition;    a second moving belt positioned at a level lower than the first belt and positioned whereby the sheet-like material travels from an end position of the first belt down a step to the second belt;    a first sensor positioned to sense break members in relation to the total thickness of the sheets on the first belt thereby causing an increased incremental movement of the first belt;    a second sensor positioned in contiguous relation to the step and adapted to sense the sheet-like material as sheets drop down the step to a second orientation thereby incrementally moving the sheet-like material according to the increasing number of sheets on the second belt as they are stacked thereon in the second orientation; and    a movable back stop member adapted to be secured to the second belt, and further adapted to help support and stack the sheets in the second orientation, the stop member moving with the movement of the second belt.    
     
     
         2 . A stacking apparatus according to  claim 1  wherein said first belt is driven by a DC motor.  
     
     
         3 . A stacking apparatus according to  claim 1  wherein said second belt is driven by a stepper motor.  
     
     
         4 . A stacking apparatus according to  claim 1  wherein said sheet-like material are mailpieces.  
     
     
         5 . A stacking apparatus according to  claim 4  wherein said mailpieces are envelopes.  
     
     
         6 . A stacking apparatus according to  claim 1  wherein said first orientation is substantially horizontal.  
     
     
         7 . A stacking apparatus according to  claim 1  wherein said second orientation is substantially vertical.  
     
     
         8 . A stacking apparatus according to  claim 1  wherein said sheets are dropped onto said second belt in a substantially vertical position.  
     
     
         9 . A stacking apparatus according to  claim 1  including means for repositioning said sheets from a first orientation to a second orientation, the repositioning means located contiguous to said step.  
     
     
         10 . A stacking apparatus according to  claim 1  further comprising a second sensor adapted to detect each time a sheet is positioned on said first belt and cause said first belt to advance each time a sheet arrives on said first belt.  
     
     
         11 . A stacking apparatus according to  claim 10  wherein said first belt advances a distance directly dependent on the length and thickness of said sheet.  
     
     
         12 . A stacking apparatus according to  claim 1  wherein stacked sheets positioned in said second orientation are strapped at said step between said first and said second belts and said back stop member.  
     
     
         13 . A stacking apparatus according to  claim 1  further comprising a plurality of third sensors positioned along said second belt, the third sensor adapted to control the movement of said second belt in relation to the position of said back stop member.  
     
     
         14 . A stacking apparatus according to  claim 4  wherein said stacking apparatus is one module of a modular mailing system.  
     
     
         15 . A stacking apparatus according to  claim 1  wherein the stacking apparatus is adapted to be used in conjunction with a mailing machine.  
     
     
         16 . A stacking apparatus according to  claim 15  wherein a main incremental movement signal for the first belt comes from the upstream feeder module in the mailing machine.  
     
     
         17 . A stacking apparatus according to  claim 1  wherein said sheet-like material is fed to said first moving belt from a position higher than said first belt.  
     
     
         18 . A stacking apparatus according to  claim 1  wherein there is positioned a braking member in contiguous relation to the sheet material positioned on said first belt, the braking member adapted to stop the movement of the sheet material and thereby position the sheets in an overlapped arrangement on said first belt.  
     
     
         19 . A stacking apparatus according to  claim 18  wherein said braking member includes a switching device adapted to detect the thickness of said sheet.  
     
     
         20 . A stacking apparatus according to  claim 19  wherein when said thickness is greater than a certain amount, said switching device sends a signal to said first belt causing said belt to speed up and thereby help remove thick envelopes from the area of the brake.  
     
     
         21 . An apparatus for stacking a stream of moving mailpieces, the apparatus adapted to be used in conjunction with a mailing system as the mailpieces are ejected seriatim from the mailing system comprising: 
 a first moving belt positioned at a first level, the first belt adapted to receive mailpieces lying in a first orientation and position the mailpieces downstream of the first belt;    a second moving belt positioned at a level lower than the first belt and positioned whereby the mail travels from an end position of the first belt down at step to the second belt;    a first sensor positioned to sense break members in relation to the total thickness of the mailpieces on the first belt thereby causing an incremental movement of the first belt;    a second sensor positioned in contiguous relation to the step and adapted to sense the mailpieces as they drop down the step to a second orientation thereby incrementally moving the mailpieces according to the increasing number of mailpieces on the second belt as the mailpieces are stacked thereon in the second orientation; and    a movable back stop member adapted to be locked onto the second belt, and further adapted to help support and stack the mailpieces in the second orientation, the stop member moving with the moving of the second belt.    
     
     
         22 . A stacking apparatus according to  claim 21  wherein said mailpieces are envelopes.  
     
     
         23 . A stacking apparatus according to  claim 21  wherein said first orientation is substantially horizontal.  
     
     
         24 . A stacking apparatus according to  claim 21  wherein said second orientation is substantially vertical.  
     
     
         25 . A method for stacking a stream of mailpieces within a mailing machine comprising: 
 positioning in a first orientation a plurality of mailpieces in an overlapped condition on a first moving belt;    positioning on a second moving belt in a second orientation the plurality of mailpieces from the first moving belt, the second belt being positioned at a lower level than the first belt;    stacking the mailpieces in the second orientation on the second belt while supporting the stack of mailpieces on the second belt; and    controlling the movement of the second belt in relation to the thickness of the stack of mailpieces on the second belt.    
     
     
         26 . A method according to  claim 25  wherein said mailpieces are envelopes.  
     
     
         27 . A method according to  claim 25  wherein said first orientation is a substantially horizontal orientation.  
     
     
         28 . A method according to  claim 25  wherein said second orientation is a substantially vertical orientation.  
     
     
         29 . A method according to  claim 25  wherein the controlling of said movement of said second belt in relation to the thickness of said stack of mailpieces on said second belt is achieved by positioning a plurality of sensors along said second belt the sensors adapted to sense the thickness of said stack.  
     
     
         30 . A method according to  claim 29  wherein said sensors are optical sensors.  
     
     
         31 . A modular mailing system including a module for stacking a stream of moving mailpieces, the stacking module comprising: 
 a first moving belt positioned at a first level, the first belt adapted to receive moving mailpieces lying in a first orientation and position the mailpieces downstream in the mailing system in an overlapped condition, the belt moving in a response to a signal from a feeding module positioned upstream in the modular mailing system;    a second moving belt positioned at a level lower than the first belt and positioned whereby the mailpieces travel from an end position of the first belt down a step to the second belt;    a first sensor positioned to sense brake members in relation to the total thickness of the mailpieces on the first belt thereby causing an increased incremental movement of the first belt;    a second sensor positioned in contiguous relation to the step and adapted to sense the mailpieces as they drop down the step to a second orientation thereby incrementally moving the mailpieces according to the increasing number of mailpieces on the second belt as they are stacked thereon in the second orientation; and    a movable back stop member adapted to be secured to the second belt, and further adapted to help support and stack the mailpieces vertically, the stop member moving with the movement of the second belt.    
     
     
         32 . A modular mailing system according to  claim 31  wherein said first orientation is substantially horizontal.  
     
     
         33 . A modular mailing system according to  claim 31  wherein said second orientation is substantially vertical.