Device for tensioning transport belts of different transport belt systems

Abstract

A device for tensioning first and second transport belts in a folder of a rotary printing press including mutually independent transport belt systems wherein the first and second transport belts are disposed, includes a tensioning unit for tensioning the first and second transport belts. The tensioning unit is disposed between the first transport belt and the second transport belt and serves for acting thereon with a force that tensions the first and second transport belts simultaneously.

We claim:  
     
         1 . In a folder of a rotary printing press having mutually independent transport belt systems with first and second transport belts, a device for tensioning the first and second transport belts, the device comprising: 
 a tensioning unit for tensioning the first and second transport belts, said tensioning unit being disposed between the first transport belt and the second transport belt for acting thereon with a force tensioning the first and second transport belts simultaneously.    
     
     
         2 . The tensioning device according to  claim 1 , wherein said tensioning unit includes a first roller-like tensioning element for acting upon the first transport belt, and a second roller-like tensioning element for acting upon the second transport belt, said second roller-like tensioning element being movable with respect to said first roller-like tensioning element and being braced by a spring-elastic force.  
     
     
         3 . The tensioning device according to  claim 1 , wherein said tensioning unit includes an actuating cylinder for receiving a pressure medium for producing the force tensioning the first and second transport belts.  
     
     
         4 . The tensioning device according to  claim 3 , wherein said actuating cylinder is a double-acting actuating cylinder with two pressure chambers to be acted upon separately from one another.  
     
     
         5 . The tensioning device according to  claim 1 , wherein said tensioning unit includes a spring element for acting between said first tensioning element and said second tensioning element for producing the force tensioning the first and second transport belts.  
     
     
         6 . The tensioning device according to  claim 5 , wherein said tensioning unit includes a system of spring elements connected in parallel, for producing a stepped pretensioning force.  
     
     
         7 . The tensioning device according to  claim 1 , wherein said tensioning unit is oriented at least approximately horizontally between the first and second transport belts.  
     
     
         8 . The tensioning device according to  claim 1 , wherein said tensioning unit is oriented at least approximately vertically between the first and second transport belts.  
     
     
         9 . The tensioning device according to  claim 1 , wherein said tensioning unit includes at least one guide element for preventing rotation of said tensioning unit.  
     
     
         10 . The tensioning device according to  claim 2 , wherein at least one of said first tensioning element and said second tensioning element of said tensioning unit are mounted on extensible holding elements formed with a cross-sectional shape for preventing rotation of said first and said second tensioning elements from a vertical position thereof.  
     
     
         11 . The tensioning device according to  claim 10 , wherein said extensible holding elements have a hexagonal cross section.  
     
     
         12 . The tensioning device according to  claim 10 , wherein said extensible holding elements are formed as multi-spline profiles.  
     
     
         13 . The tensioning device according to  claim 10 , wherein said extensible holding elements are formed with a longitudinal groove, for engagement therein of a projection provided on a body of said tensioning unit.  
     
     
         14 . The tensioning device according to  claim 10 , wherein said tensioning unit is one of a multiplicity of tensioning units mounted to be positioned in a plane for tensioning a multiplicity of first and second transport belts.  
     
     
         15 . The tensioning device according to  claim 14 , wherein said plane is a horizontal plane.  
     
     
         16 . The tensioning device according to  claim 14 , wherein said tensioning units are positioned parallel to one another on said holding element.  
     
     
         17 . The tensioning device according to  claim 16 , wherein said plane is a horizontal plane, and said tensioning units are to be positioned on said holding element with an angular offset in relation to one another in said horizontal plane.  
     
     
         18 . The tensioning device according to  claim 14 , wherein said tensioning units are mounted in said holding element in a displaceable holder, within a guide region, relative to said holding element.  
     
     
         19 . The tensioning device according to  claim 1 , wherein said tensioning unit is disposed on a holding element and is enclosed by components of said holding element.