Turning Device for Turning Over Sheets in a Printing Machine

Abstract

The invention relates to a turning device ( 1 ) for transporting and turning over sheets ( 2 ) of printing material in a printing machine, preferably an electrophotographic printing machine, said device comprising at least two belts ( 7, 8 ), which, in particular, consist essentially of a plastic material, each of said belts being deflected as closed loops over respectively at least two deflecting elements ( 22, 23 ) and being crossed in order to turn over the respective sheet by approximately 180 degrees about its axis pointing in transport direction, in which process said sheet is held by clamping and frictional engagement between abutting segments ( 7′, 8 ′) of the tensioned belt, whereby at least one of the belts ( 7, 8 ), preferably each belt, is configured in a non-elastic manner, specifically reinforced, and that, in order to tension this belt, a tensioning device is provided.

1 . Turning device for transporting and turning over sheets of printing material in a printing machine, preferably an electrophotographic printing machine, said device comprising at least two belts, which, in particular, consist essentially of a plastic material, each of said belts being deflected as closed loops over respectively at least two deflecting elements and being crossed in order to turn over the respective sheet by approximately 180 degrees about its axis pointing in transport direction, in which process said sheet is held by clamping and frictional engagement between abutting segments of the tensioned belt, characterized in that
 at least one of the belts is configured in a non-elastic manner, specifically reinforced, and that, in order to tension this belt, a tensioning device is provided.   
   
   
       2 . Turning device as in  claim 1 , characterized in that the tensioning device comprises a deflecting element which deflects or bends the belt. 
   
   
       3 . Turning device as in  claim 2 , characterized in that the deflecting element is a roller. 
   
   
       4 . Turning device as in  claim 2  or  3 , characterized in that the deflecting element is subject to a spring bias in tensioning direction. 
   
   
       5 . Turning device as in  claim 2 ,  3  or  4 , characterized in that the belt is deflected essentially in S-form over two deflecting elements in the region of a tensioning device.