Velocity-changing apparatus for web

Abstract

A velocity-changing apparatus of the present invention includes: a drum 3 for transporting the continuous web W 1 at a transport velocity which is generally equal to a circumferential velocity V(θ) of the drum 3 while changing the circumferential velocity V(θ) periodically at least once per one rotation of the drum 3 ; a movable member 2 disposed upstream of the drum 3 for feeding the continuous web W 1 to the drum 3,; and a cutter 4 for cutting, on the drum 3, the continuous web W 1 being transported at the transport velocity which is generally equal to the circumferential velocity V(θ) of the drum 3. The movable member 2 moves according to the change of the circumferential velocity V(θ) of the drum 3 so that a feed velocity at which the continuous web W 1 is fed to the drum 3 is generally equal to the transport velocity of the continuous web W 1 being transported by the drum 3.

1 . A velocity-changing apparatus for changing a velocity of a continuous web comprising: 
 a drum for transporting the continuous web at a transport velocity which is generally equal to a circumferential velocity of the drum while changing the circumferential velocity periodically at least once per one rotation of the drum;    a movable member disposed upstream of the drum for feeding the continuous web to the drum, the movable member moving according to the change of the circumferential velocity of the drum so that a feed velocity at which the continuous web is fed to the drum is generally equal to the transport velocity of the continuous web being transported by the drum; and    a cutter for cutting, on the drum, the continuous web being transported at the transport velocity which is generally equal to the circumferential velocity of the drum.    
   
   
       2 . A velocity-changing apparatus according to  claim 1 , further comprising a processing device for processing the continuous web on the drum.  
   
   
       3 . A velocity-changing apparatus according to  claim 2 , wherein 
 the processing device is a welder for welding the continuous web.    
   
   
       4 . A velocity-changing apparatus according to  claim 3 , wherein 
 the processing device processes the continuous web when the transport velocity at which the drum transports the continuous web is lower than an average circumferential velocity of the drum.    
   
   
       5 . A velocity changing apparatus according to  claim 4 , wherein 
 the cutter cut the continuous web when the transport velocity at which the drum transports the continuous web is lower than the average circumferential velocity of the drum.    
   
   
       6 . A velocity changing apparatus according to  claim 5 , further comprising a receiving device for receiving a cut-off web cut off by the cutter and then transporting the cut-off web, wherein 
 a velocity at which the received cut-off web is transported by the receiving device when the receiving device receives the cut-off web is larger than the transport velocity of the continuous web when the continuous web is cut,    whereby a tip end of the continuous web get spaced apart from a rear end of the cut-off web.