Apparatus and method of increasing web storage in a dancer

Abstract

An improved web accumulator with two arms where at least one arm is a swinging dancer arm and at least one arm is attached to a sliding carriage. Each arm has a set of rollers attached. A web is threaded alternately between the two sets of rollers. The arms are mechanically connected to move simultaneously towards or away from each other. The arms are initially position at their maximum separation to accumulate a maximum length of web. When web infeed is interrupted while web outfeed or draw persists, the arms are first rotated in towards each other to pay out the stored length of web. As the demand persists and the dancer arm is rotated beyond some predefined position, the sliding carriage begins to slide to a least storage position. As web infeed returns to normal operational speeds, the dancer arm and the sliding carriage are returned to their original position to again accumulate a maximum amount of web.

1 . A web accumulator for accumulating and paying out a portion of a continuous moving web passing through the accumulator comprising: 
 a first rotating dancer arm carrying a first plurality of rollers for engaging a moving web;    a second dancer arm carrying a second plurality of rollers for engaging said web;    at least one of said arms being slidably mounted to a body;    a drive mechanism associated with said slidably mounted arm, wherein said slidably mounted arm can be driven in a first substantially linear direction toward the other arm, and a second substantially linear direction away from the other arm;    whereby the length of travel of the web can be varied by radial movement of the first rotating dancer arm and linear movement of at least one of the dancer arms.    
   
   
       2 . A web accumulator according to  claim 1 , said first rotating dancer arm carried by a first carriage.  
   
   
       3 . A web accumulator according to  claim 2 , said second dancer arm carried by a second carriage.  
   
   
       4 . A web accumulator according to  claim 3 , said first and second carriages coupled to each other, wherein said both said first and second carriages are slidably mounted to a body.  
   
   
       5 . A web accumulator according to  claim 4 , said first and second carriages coupled by a toothed belt, wherein movement of said belt cause movement of said first and second carriages.  
   
   
       6 . In combination, a linear accumulator and a rotating arm dancer, wherein said rotating arm dancer and said linear accumulator operate in conjunction to first accumulate and second pay out a portion of a continuous moving web passing through the accumulator.  
   
   
       7 . A web accumulator for accumulating and paying out a portion of a continuous moving web passing through the accumulator comprising: 
 a first rotating dancer arm carrying a first plurality of rollers for engaging a moving web;    a second rotating dancer arm carrying a second plurality of rollers for engaging said web;    at least one of said arms being slidably mounted to a body;    a drive mechanism associated with said slidably mounted arm, wherein said slidably mounted arm can be driven in a first substantially linear direction toward the other arm, and a second substantially linear direction away from the other arm;    whereby the length of travel of the web can be varied by linear movement of at least one of the dancer arms and radial movement of the first rotating dancer arm.    
   
   
       8 . A web accumulator according to  claim 7  wherein the second arm is identical to the first arm.  
   
   
       9 . A web accumulator according to  claim 8 , said second arm rotated approximately 180 degrees from from said first arm when said arms are in a maximum storage position.  
   
   
       10 . A web accumulator according to  claim 7  wherein the second arm is a mirror image of the first arm and the arms are configured such that an angle of approximately 90 degrees is formed between the arms when the arms are in a maximum storage position.