Coreless winding apparatus

Abstract

Disclosed is an apparatus for forming coreless paper rolls. The invention is an inflatable mandrel that can take on an increased diameter while a paper web is being wound around its outer surface. The mandrel can then be deflated to decrease the diameter sufficiently to allow for the removal of the paper roll.

1 . A mandrel for use within a winding apparatus having opposing mandrel guides, the mandrel permitting the production of coreless rolls and comprising: 
 an elongated rigid shaft having a length of 53.5″ or greater, an outer cylindrical surface, first and second ends and an intermediate extent therebetween, the shaft including a hollow interior with first and second threaded extents, recesses formed within the outer cylindrical surface, first and second air ports formed through the outer cylindrical surface proximate the first and second threaded extents;    a length of flexible tubing formed from polyvinylchloride, the tubing having a length that is equal to the length of the rigid shaft, the tubing fitted over top of the outer cylindrical surface of the rigid shaft, lengths of thread wound around the flexible tubing over the recesses to thereby form a seal between the flexible tubing and the rigid shaft;    a threaded end cap threadably secured within the first threaded extent of the rigid shaft, the threaded end cap including an integral air valve for selectively delivering pressurized air into the hollow interior of the rigid shaft;    a threaded plug with a peripheral seal threadably secured within the second threaded extent of the rigid shaft such that the peripheral seal forms a fluid tight barrier within the second end of the rigid shaft;    a source of compressed air for delivery to the hollow interior of the rigid shaft via the air valve, and through the air ports, the delivery of compressed air causing annual spaces to be created between the recesses of the shaft and between the shaft and the tubing, the creation of the annular spaces in turn causing an increase in the outer diameter of the mandrel, the air valve functioning to retain the compressed air within the mandrel while the mandrel is mounted to the mandrel guides of the winding apparatus, the air valve further functioning to allow an operator to selectively release the compressed air from the mandrel after the mandrel is removed from the mandrel guides at the conclusion of winding operations.    
     
     
         2 . An expansible mandrel comprising: 
 a shaft with first and second ends and a hollow interior and at least one air port formed along its length;    a length of tubing secured over the shaft, the tubing being sealed to the first and second ends of the shaft;    an air valve coupled to one end of the shaft;    a source of compressed air for selective delivery into the hollow interior of the shaft and through the air port, whereby the tubing is inflated and the diameter of the mandrel is increased.    
     
     
         3 . The mandrel as described in  claim 2  wherein the air valve is incorporated into an end cap that is threadably secured within an end of the shaft.  
     
     
         4 . The mandrel as described in  claim 2  wherein the tubing is sealed to the shaft via wound thread and adhesive.  
     
     
         5 . The mandrel as described in  claim 2  wherein the length of the mandrel is greater than 53.5″.  
     
     
         6 . The mandrel is described in  claim 2  wherein the outer diameter of the mandrel in its expanded state is less than 0.875″.  
     
     
         7 . The mandrel as described in  claim 2  wherein the tubing is a flexible polyvinylchloride tubing.  
     
     
         8 . A method of making coreless rolls, the method employing a mandrel adapted to be removably secured between the opposing mandrel guides of a winding apparatus, the mandrel having an inner rigid shaft with an air valve and an air port and having an outer flexible tubing that is secured over top of the shaft, the method comprising the following steps: 
 supplying air under pressure into the shaft via the air valve, the pressurized air being expelled from the shaft via the air port and causing the outer flexible tubing to expand to an increased diameter, whereby the mandrel is in an inflated state;    removing the supply of air under pressure, whereby the air valve is closed and the mandrel is maintained in an inflated state;    securing the mandrel in the inflated state between the opposing mandrel guides of the winding apparatus;    winding a sheet of material over the mandrel while it is in the inflated state;    removing the mandrel from the opposing mandrel guides after a sufficient amount of material has been wound upon the mandrel;    manually engaging the air valve to permit pressurized air to escape from the mandrel, whereby the flexible tubing contracts and the mandrel takes on a deflated state;    sliding the wound material off of the mandrel while the mandrel is in the deflated state.    
     
     
         9 . The method as described in  claim 8  wherein a number of separate register receipt rolls are formed upon the mandrel.  
     
     
         10 . The method as described in  claim 8  wherein the user employs a tool to manually engage the air valve.