Method for producing a rotationally symmetrical, in particular cylindrical screening device

Abstract

Method for producing a rotationally symmetrical screening device with a plurality of profile bars and screening basket for a pressurized screen. The method includes inserting profile bars parallel to each other into cut-outs open on an interior circumference edge of bar holders and forming the bar holders into rings, thereby narrowing the cut-outs and clamping the profile bars. The forming of rings includes transferring bending forces to at least two locations on sides of the bar holders not provided with the cut-outs. The method further includes connecting abuttable ends of the bar holders to one another.

1 . A method for producing a rotationally symmetrical screening device with a plurality of profile bars, comprising: 
 inserting profile bars parallel to each other into cut-outs open on an interior circumference edge of bar holders;    forming the bar holders into rings, thereby narrowing the cut-outs and clamping the profile bars, wherein the forming of rings includes transferring bending forces to at least two locations on sides of the bar holders not provided with the cut-outs; and    connecting abuttable ends of the bar holders to one another.    
     
     
         2 . The method in accordance with  claim 1 , wherein the rotationally symmetrical screening device is cylindrical.  
     
     
         3 . The method in accordance with  claim 1 , wherein the profile bars include base portions insertable into the cut-outs, and the cut-outs are shaped to essentially correspond in a complementary manner to the base portions of the profile bars.  
     
     
         4 . The method in accordance with  claim 1 , wherein the location for introducing the bending forces essentially extends over an axial extension of the screening device.  
     
     
         5 . The method in accordance with  claim 4 , wherein the location is fixed on the bar holder during forming.  
     
     
         6 . The method in accordance with  claim 1 , wherein the bending forces act both radially inward and in the circumferential direction.  
     
     
         7 . The method in accordance with  claim 1 , wherein during the forming, no forces influencing the forming are transferred to the interior circumference surface of the bar holder to be formed into a ring.  
     
     
         8 . The method in accordance with  claim 1 , wherein no mating shape is used during forming.  
     
     
         9 . The method in accordance with  claim 1 , further comprising applying the bending forces during the connecting of the abuttable ends of the bar holders.  
     
     
         10 . The method in accordance with  claim 9 , wherein complete rings are formed by the connecting of the abuttable ends of the bar holders.  
     
     
         11 . The method in accordance with  claim 1 , further comprising clamping the bar holders during the forming in the bending devices applying the bending forces.  
     
     
         12 . The method in accordance with  claim 1 , wherein the bending forces are introduced at a maximum of four locations.  
     
     
         13 . The method in accordance with  claim 12 , wherein four bending devices are used to introduce the bending forces at the maximum of four locations.  
     
     
         14 . The method in accordance with  claim 12 , wherein respectively two bending devices form a bending group which, in interaction, transfers a bending moment to the bar holders.  
     
     
         15 . The method in accordance with  claim 1 , wherein the bending forces are introduced at six locations.  
     
     
         16 . The method in accordance with  claim 15 , wherein four bending devices and two backing rolls are arranged to introduce the bending forces at the six locations.  
     
     
         17 . The method in accordance with  claim 15 , wherein respectively two bending devices and one backing roll form a bending group which, in interaction, transfers a bending moment to the bar holders.  
     
     
         18 . The method in accordance with  claim 1 , wherein the abuttable ends of the bar holders are connected to one another by welding.  
     
     
         19 . The method in accordance with  claim 1 , wherein the forming and the connecting of the abuttable ends of the bar holders are carried out with a same machine.  
     
     
         20 . The method in accordance with  claim 1 , wherein the bar holders are assembled from segments before the forming.  
     
     
         21 . The method in accordance with  claim 1 , wherein, the profile bars are inserted into a bar holder having an open cylinder shape in which the abuttable ends are spaced from each other.  
     
     
         22 . The method in accordance with  claim 21 , wherein the forming comprises forming a butt joint comprising the abuttable ends.  
     
     
         23 . The method in accordance with  claim 22 , further comprising welding the butt joint.  
     
     
         24 . A screen basket for a pressurized screen usable in the paper-producing industry, produced by the method of  claim 1.