Device For Superimposing Adjacent Sheets In A Conveying Line

Abstract

A device is associated to an automatic enveloping machine for superimposing sheets or packets of sheets. In the device a first belt conveyor group receives one sheet packet of sheets from a conveying line located upstream and conveys the sheet or packet of sheets along a first path, first raising and then going down, toward an outlet station. A second belt conveyor group receives a second sheet or packet of sheets from the conveying line and conveys the sheet of packet of sheets along a second path, first going down and then raising, having the same length as the first path, toward the outlet station. At the outlet station the sheet or packet of sheets coming from the first path is placed over the sheet or packet of sheets coming from the second path, to define a package.

1 . A device for superimposing adjacent sheets or packets of sheets in a conveying line, the line being part of an automatic machine for preparation and enveloping of packages formed by two superimposed sheets or by two superimposed packets of sheets, said device including:
 a first belt conveyor group for receiving a first sheet or packet of sheets from said conveying line and for conveying said first sheet or packet of sheets along a prefixed first path, first raising and then going down, and toward an outlet station, to define an upper sheet or an upper packet of sheets of said package being formed;   a second belt conveyor group for receiving a second sheet or packet of sheets from the same conveying line and for conveying said second sheet or packet of sheets along a prefixed second path, first going down and then raising, toward said outlet station, to define a lower sheet or lower packet of sheets of said package being formed, with said belt conveyor groups determining longitudinal alignment of front edges of said sheets or packets of sheets, at said outlet station   
   
   
       2 . A device, according to  claim 1 , wherein each of said first and second conveyor groups includes a pair of endless belts, respectively an upper endless belt and a lower endless belt, mounted on relevant pulleys having horizontal axis, the endless belts of each pair of endless belts being operated so as to counter-rotate with equal speed, with the upper endless belt of each group of endless belts facing a relevant lower endless belt to define a corresponding first operating run extending along said first path, and a second operating run extending along said second oath. 
   
   
       3 . A device, according to  claim 1 , wherein a downstream return pulley of said lower endless belt of said first belt conveyor group is set back with respect to a corresponding return pulley of said upper endless belt. 
   
   
       4 . A device, according to  claim 1 , wherein a downstream return pulley of said lower endless belt of said second belt conveyor group is offset to an advanced position with respect to a corresponding return pulley of the upper endless belt. 
   
   
       5 . A device, according to  claim 1 , wherein said first path includes consecutive portions of said first operating run having different inclination for increasing contact pressure between related opposite belt conveyors of said first belt conveyor group, consequently, gripping action performed on the sheet or packet of sheets. 
   
   
       6 . A device, according to  claim 1 , wherein said second path includes consecutive portions of said second operating run having different inclination for increasing contact pressure between related opposite belt conveyors of said second belt conveyor group, consequently, gripping action performed on the sheet or packet of sheets. 
   
   
       7 . A device, according to  claim 1 , wherein said first and second paths have equal length. 
   
   
       8 . A device, according to  claim 2 , wherein an upstream return pulley of the upper endless belt of the first belt conveyor group is aligned with a corresponding upstream return pulley of the upper endless belt of the second belt conveyor group, and an upstream return pulley of the lower endless belt of the first belt conveyor group is aligned with a corresponding upstream pulley of the lower endless belt of the second belt conveyor group, whereas said upstream return pulleys of the upper endless belts are set back with respect to corresponding return pulleys of the lower endless belts. 
   
   
       9 . A device, according to  claim 2 , wherein a downstream return pulley of said lower endless belt of said first belt conveyor group is set back with respect to a corresponding return pulley of said upper endless belt. 
   
   
       10 . A device, according to  claim 2 , wherein a downstream return pulley of said lower endless belt of said second belt conveyor group is offset to an advanced position with respect to a corresponding return pulley of the upper endless belt. 
   
   
       11 . A device, according to  claim 2 , wherein said first path includes consecutive portions of said first operating run having different inclination for increasing contact pressure between related opposite belt conveyors of said first belt conveyor group, consequently, gripping action performed on the sheet or packet of sheets. 
   
   
       12 . A device, according to  claim 2 , wherein said second path includes consecutive portions of said second operating run having different inclination for increasing contact pressure between related opposite belt conveyors of said second belt conveyor group, consequently, gripping action performed on the sheet or packet of sheets. 
   
   
       13 . A device, according to  claim 2 , wherein said first and second paths have equal length.