Method for controlling and/or monitoring a web-processing machine

Abstract

A method for controlling and/or monitoring a web-processing machine ( 1 ) is introduced, wherein at least one web ( 5 ) of the web-processing machine ( 1 ) is unwound from the roll ( 12 ) of an unwinding device and is supplied to the machine ( 1 ), wherein the point in time (T) at which the web end on the roll is reached is determined and control signals are emitted depending on this point in time (T). The novelty and inventive step of the invention is that the angular speed (ω) of the roll ( 12 ) and the speed (v) of the web ( 5 ) are recorded and that the point in time (T) is determined taking both these variables (v, ω) into consideration. A device ( 1 ) for implementing the method is also described and forms the subject of the patent request.

1 : Method for controlling and/or monitoring a web-processing machine ( 1 ), 
 wherein at least one web ( 5 ) of the web-processing machine ( 1 ) is unwound from the roll ( 12 ) of an unwinding device and is supplied to the machine ( 1 ), wherein the point in time (T) at which the web end on the roll ( 12 ) is reached, is determined and wherein control signals are emitted depending on this point in time (T),    said method being characterized in that    the angular speed (ω) of the roll ( 12 ) is recorded,    that the speed (v) of the web ( 5 ) is recorded,    and that the point in time (T) is determined taking both these values (v, ω) into consideration.    
   
   
       2 : Method according to  claim 1 , 
 characterized in that    when determining the point in time (T), the minimum diameter of the roll ( 12 ) and/or the diameter of the winding sleeve ( 14 ) are taken into consideration.    
   
   
       3 : Method according to  claim 1   characterized in that    the material thickness of the web ( 5 ) is calculated from the development of the circumference of the roll ( 12 ) per rotation.    
   
   
       4 : Method according to the preceding claim 
 characterized in that    the development of the circumference of the roll ( 12 ) is averaged over several rotations.    
   
   
       5 : Method according to  claim 3   characterized in that    the material thickness is taken into account when determining the point in time (T).    
   
   
       6 : Method according to  claim 1   characterized in that    the web speed (v) is measured using a rotary encoder, which records the rotations of a roller ( 3 ,  4 ), which is mechanically connected to the web ( 5 ).    
   
   
       7 : Method according to the preceding claim, 
 characterized in that    the web speed is measured using a roller ( 3 ,  4 ), which rolls off with the web ( 5 ).    
   
   
       8 : Web-processing machine ( 1 ) 
 having an unwinding device ( 11 ), in which ( 1 ) at least one web ( 5 ) can be unwound from a roll ( 11 ) and can be supplied to the processing part of the machine ( 1 ),    and also having a control device using which the point in time (T), at which the web end on the roll ( 12 ) is reached, can be determined, characterized by 
 a means ( 20 ,  21 ) for recording the angular speed (ω) of the roll ( 11 ),  
 a means for recording the speed (v) of the web ( 5 ), a control device using which both these values (v, ω) can be taken into consideration when determining the point in time (T).  
   
   
   
       9 : Method according to  claim 2 , 
 characterized in that    the material thickness of the web ( 5 ) is calculated from the development of the circumference of the roll ( 12 ) per rotation.    
   
   
       10 : Method according to  claim 4 , 
 characterized in that    the material thickness is taken into account when determining the point in time (T).    
   
   
       11 : Method according to  claim 2 , 
 characterized in that    the web speed (v) is measured using a rotary encoder, which records the rotations of a roller ( 3 ,  4 ), which is mechanically connected to the web ( 5 ).    
   
   
       12 : Method according to  claim 3 , 
 characterized in that    the web speed (v) is measured using a rotary encoder, which records the rotations of a roller ( 3 ,  4 ), which is mechanically connected to the web ( 5 ).    
   
   
       13 : Method according to  claim 4 , 
 characterized in that    the web speed (v) is measured using a rotary encoder, which records the rotations of a roller ( 3 ,  4 ), which is mechanically connected to the web ( 5 ).    
   
   
       14 : Method according to  claim 5 , 
 characterized in that    the web speed (v) is measured using a rotary encoder, which records the rotations of a roller ( 3 ,  4 ), which is mechanically connected to the web ( 5 ).