Easily removable selvage device

Abstract

The problems associated with the prior art have been overcome by the present invention, which describes a device for spooling selvage as it is cut by a side-sealing machine. The device includes a two part core, which is held together by a friction fitting, such as a keyless bushing. The two parts of the core are shaped so that as the selvage is wound onto the core, it exerts both a radial and axial force on the core. This axial force provides the force needed to separate the two parts of the core when the bushing is removed. Various shaped core parts may be used, and various friction fittings are also envisioned.

What is claimed is: 
     
         1 . A side sealing machine for sealing a film, comprising:
 a cutting and heating element, having a leading edge adapted to encounter said film first, and to separate a portion of said film as selvage; and   a spool for holding said selvage after it has been cut by said cutting and heating element; said spool comprising:
 a rod on which a core is placed, said core adapted to rotate to allow said selvage to accumulate on said spool; 
 said core comprising at least one core portion, said core portion having an incline angle relative to a axis passing through said rod, said incline angle being sufficiently steep so as to translate a compression force caused by shrinking and cooling of said selvage into an axial force, said axial force sufficient to separate said core portion from an adjacent component located on said rod; and 
 a fastener to hold said core onto said rod. 
   
     
     
         2 . The side sealing machine of  claim 1 , wherein said core portion is frustoconical, having a narrower end and a wider end. 
     
     
         3 . The side sealing machine of  claim 2 , wherein said adjacent component comprises a vertical wall adjacent to said narrower end of said frustoconical core portion. 
     
     
         4 . The side sealing machine of  claim 2 , wherein said adjacent component comprises a second frustoconical core portion, having a narrower end and a wider end, arranged such that said narrower end of said frustoconical core portion is adjacent to said narrower end of said second frustoconical core portion. 
     
     
         5 . The side sealing machine of  claim 4 , wherein said second frustoconical core portion is identical to said core portion. 
     
     
         6 . The side sealing machine of  claim 4 , comprising two vertical walls, one adjacent to each wider end of a respective frustoconical core portion. 
     
     
         7 . The side sealing machine of  claim 1 , wherein said fastener utilizes radial force to secure itself to said rod. 
     
     
         8 . The side sealing machine of  claim 7 , wherein said fastener comprises a keyless bushing. 
     
     
         9 . The side sealing of  claim 8 , wherein said fastener comprises a hydraulic keyless bushing. 
     
     
         10 . The side sealing machine of  claim 1 , wherein said incline angle is greater than about 15°. 
     
     
         11 . A side sealing machine for sealing a film, comprising:
 a cutting and heating element, having a leading edge adapted to encounter said film first, and to separate a portion of said film as selvage; and   a spool for holding said selvage after it has been cut by said cutting and heating element; said spool comprising:
 a rod on which a core is placed, said core adapted to rotate to allow said selvage to accumulate on said spool; 
 said core comprising a first core portion, said core portion having an incline angle relative to a axis passing through said rod, said incline angle being sufficiently steep so as to translate a compression force caused by shrinking and cooling of said selvage into an axial force, said axial force sufficient to separate said first core portion from an adjacent second core portion located on said rod; and 
 a fastener to hold said core onto said rod. 
   
     
     
         12 . The side sealing machine of  claim 11 , wherein said first and second core portions are frustoconical, each having a narrower end and a wider end, wherein said narrower ends are adjacent to one another. 
     
     
         13 . The side sealing machine of  claim 12 , further comprising two vertical walls adjacent each wider end of said first and second core portions. 
     
     
         14 . The side sealing machine of  claim 11 , wherein said fastener uses radial force to secure itself to said rod. 
     
     
         15 . The side sealing machine of  claim 14 , wherein said fastener comprises a keyless bushing. 
     
     
         16 . The side sealing machine of  claim 11 , wherein said incline angle is greater than about 15°. 
     
     
         17 . A side sealing machine for sealing a film, comprising:
 a cutting and heating element, having a leading edge adapted to encounter said film first, and to separate a portion of said film as selvage; and   a spool for holding said selvage after it has been cut by said cutting and heating element; said spool comprising:
 a rod on which a core is placed, said core adapted to rotate to allow said selvage to accumulate on said spool; 
 said core comprising a first frustoconical core portion, said first core portion having a narrower end and a wider end, and a first incline angle relative to a axis passing through said rod, and an adjacent second frustoconical core portion having a narrower end and a wider end, and a second incline angle relative to a axis passing through said rod; wherein said narrower ends of said first and second core portions are adjacent to one another; said first and second incline angles being sufficiently steep so as to translate a compression force caused by shrinking and cooling of said selvage into an axial force, said axial force sufficient to separate said first core portion from said adjacent second frustoconical core portion; and 
 a fastener to hold said core portions onto said rod. 
   
     
     
         18 . The side sealing machine of  claim 17 , wherein said fastener uses radial force to secure itself to said rod. 
     
     
         19 . The side sealing machine of  claim 18 , wherein said fastener comprises a keyless bushing. 
     
     
         20 . The side sealing machine of  claim 17 , wherein said incline angle is greater than about 15°.