Reel spool shaft for use with cores

Abstract

The invention employs a fluid cushion between a shaft and cylindrical core to reduce friction between the core and shaft. Reduced friction at the shaft/core interface lowers the forces required to separate rolls of web material from the shaft. Lower separation forces should mean less damage to the wound web material and less wear and tear on the shaft and extraction equipment.

1 . A shaft for supporting a web wound on a tubular core surrounding the shaft with frictional forces between said core and said shaft, said shaft comprising: 
 a connection for receiving pressurized fluid pressurized fluid; and    a fluid path communicating with said connection to inject said pressurized fluid between said spool and said core,    wherein said injected fluid reduces the frictional forces between said core and said spool.    
   
   
       2 . The shaft of  claim 1 , wherein said shaft is partially or wholly hollow and said fluid path comprises a fluid inlet directing said pressurized fluid into said hollow shaft and a plurality of outlets through said shaft allowing fluid flow out of said shaft between said shaft and said core.  
   
   
       3 . The shaft of  claim 1 , wherein said fluid is compressed air.  
   
   
       4 . The shaft of  claim 1 , wherein said fluid is a compressed gas and includes a liquid or solid lubricant dispersed by said compressed gas.  
   
   
       5 . The shaft of  claim 1 , wherein said fluid is a lubricant.  
   
   
       6 . The shaft of  claim 1 , wherein said shaft has an outside surface adjacent an inside surface of said core, said outside surface including friction reducing elements.  
   
   
       7 . The reel spool of  claim 6 , wherein said friction reducing elements include a friction reducing coating on said outside surface.  
   
   
       8 . A method for reducing friction between a shaft and a tubular core surrounding the shaft, said method comprising: 
 providing a fluid path to an annular interface between said shaft and said core;    injecting pressurized fluid into said interface.    
   
   
       9 . The method of  claim 8 , wherein said shaft is partially or wholly hollow and the step of providing a fluid path comprises: 
 injecting a fluid through an inlet communicating with an interior of said hollow shaft; and    directing said pressurized fluid between said shaft and said core through perforations in said shaft.    
   
   
       10 . The method of  claim 8 , wherein said step of injecting pressurized fluid comprises: 
 injecting compressed air into said interface.    
   
   
       11 . The method of  claim 8 , wherein said step of injecting pressurized fluid comprises: 
 injecting compressed gas carrying a lubricant into said interface.    
   
   
       12 . The method of  claim 8 , wherein said step of injecting pressurized fluid comprises: 
 injecting a liquid into said interface.    
   
   
       13 . The method of  claim 8 , wherein said shaft has an outside surface and said method comprises: 
 configuring said outside surface with friction reducing elements.    
   
   
       14 . The method of  claim 13 , wherein said step of configuring comprises: 
 coating said outside surface with a friction reducing coating.    
   
   
       15 . A shaft for receiving a core for installation in a web take-up system in a paper making machine, said shaft comprising: 
 a cavity defined within said shaft;    a plurality of fluid flow passages communicating between said cavity and an outside surface of said shaft; and    a connection for receiving pressurized fluid, said connection communicating with said cavity.    
   
   
       16 . The shaft of  claim 15 , wherein said shaft has an axis of rotation and said connection is aligned with said axis of rotation.  
   
   
       17 . The shaft of  claim 15 , wherein said shaft has an outside surface including friction reducing elements.  
   
   
       18 . The shaft of  claim 17 , wherein said friction reducing elements include a friction reducing coating on said outside surface.  
   
   
       19 . The shaft of  claim 15 , wherein said shaft has an axis of rotation and said connection is coaxial with said axis of rotation.  
   
   
       20 . A shaft for receiving a core for installation in a web take-up system in a paper making machine, said shaft comprising: 
 a generally cylindrical outside surface; and    a plurality of friction reducing elements arranged to reciprocate between a retracted position radially inward of said outside surface and an extended position radially projecting from said outside surface; and    means for moving said plurality of friction reducing elements between said retracted and extended positions,    wherein said friction reducing elements in the extended position reduce frictional forces between a received core and said outside surface.    
   
   
       21 . The shaft of  claim 20 , wherein said shaft comprises a connection for receiving pressurized fluid and said means for moving comprises said pressurized fluid.  
   
   
       22 . The shaft of  claim 20 , wherein said friction reducing elements include rollers arranged to protrude from said outside surface when said friction reducing elements are in the extended position.