Reel changer of a web-fed printing press

Abstract

A reel changer of a web-fed printing press includes a load-bearing axle and a carrying arm having at least two carrying-arm segments. A printing-material reel may be mounted or clamped between the carrying-arm segments of the carrying arm. The printing-material reel is displaceable relative to the load-bearing axle using the carrying-arm segments in a production mode. A control system and a safety system which operates independently of the control system both monitor the relative spacing between the carrying-arm segments and blocks the respective carrying-arm segments in the event of an impermissible spacing deviation in the production mode. The safety system includes a separate distance measuring device dedicated to each carrying-arm segment, which distance measuring devices interact with an evaluation device.

1 . A reel changer of a web-fed printing press, comprising: 
 a load-bearing axle including a carrying arm having at least two carrying-arm segments, said load bearing axle being movable for moving said carrying arm between a loading mode and a production mode, said carrying arm being arranged and dimensioned for receiving a printing-material reel in said loading mode, whereby the printing material reel is mountable or clampable between said carrying-arm segments in the loading mode, and said carrying arm being further arranged and dimensioned such that said carrying-arm segments are displaceable relative to said load-bearing axle in said production mode, whereby the printing-material reel is displaceable relative to said load-bearing axle by said carrying-arm segments;    a control system monitoring a relative spacing between said carrying-arm segments in said production mode and blocking movement of said carrying-arm segments in the event of an impermissible spacing deviation; and    a safety system operating independently of said control system, said safety system comprising distance measuring devices connected to an evaluation device for monitoring the relative spacing between said carrying-arm segments in the production mode and blocking movement of said carrying-arm segments in the event of an impermissible spacing deviation, each of said distance measuring devices corresponding to a respective one of said carrying-arm segments.    
     
     
         2 . The reel changer of  claim 1 , wherein each of said distance measuring devices of said safety system comprises one encoder and one counter, said encoders comprising position transmitters of said respective carrying-arm segments and incrementing said counters upwards or downwards in response to a direction of displacement of said carrying-arm segments, wherein said evaluation device infers an impermissible spacing deviation of said carrying-arm segments and blocking movement of said carrying-arm segments if the difference between the counters deviates from a setpoint value by a defined amount.  
     
     
         3 . The reel changer of  claim 2 , wherein said evaluation device includes a subtractor which subtracts the counter readings of said counters and monitors whether the difference between said counters deviates from the setpoint value by the defined amount.  
     
     
         4 . The reel changer of  claim 2 , wherein the setpoint value is determined from a spacing between said carrying-arm segments after a printing-material reel is mounted or clamped on said carrying arm in said loading mode.  
     
     
         5 . The reel changer of  claim 1 , wherein said control system comprises absolute value encoders as position transmitters of said carrying-arm segments.  
     
     
         6 . The reel changer of  claim 1 , wherein said safety system monitors the relative spacing between said carrying-arm segments of said carrying arm in said loading mode and said production mode, and blocks movement of said carrying-arm segments of said carrying arm in the event of an impermissible spacing deviation only in said production mode.  
     
     
         7 . The reel changer of  claim 1 , wherein said loading mode and said production mode are determined as a function of an angular position of the load-bearing axle.  
     
     
         8 . The reel changer of  claim 1 , further comprising a separate motor for driving each of said carrying-arm segments, wherein at least one of said control system and said safety system block said motors in the production mode in the event of an impermissible spacing deviation to block movement of said carrying-arm segments.