Core for aluminum sheet

Abstract

A core for winding metal sheet thereon to provide the sheet metal free of lap marks upon unwinding, the core having a generally cylindrical configuration and having an outside surface, said outside surface having a wedge-shaped notch formed generally transverse to winding direction of the core, the notch having a stepped end and a tapered end disposed opposite the stepped end, the stepped end extending from the surface to a bottom, the stepped end having a tapered end extending from the bottom of stepped end to the outside surface of said core to provide a transition zone.

1 . A method of winding a metal sheet on a core to avoid formation of arbor deformities or lap marks, comprising the steps of: 
 (a) providing a source of metal sheet to be wound on a core;    (b) providing a core on which the metal sheet is to be wound, said core being generally cylindrical and having a circumference and an outside surface, said outside surface having: 
 a notch formed generally transverse to winding direction of said core, said notch having a stepped end and a tapered end disposed generally opposite said stepped end, said stepped end suited to having an end of said sheet abutted thereagainst, the tapered end extending from the bottom of said notch to said outside surface of said core to provide a transition zone;  
   (c) abutting an end of said sheet against the stepped end of said core; and    (d) winding said sheet on said core, said sheet being free of arbor deformities or lap marks after being wound on said core.    
   
   
       2 . The method in accordance with  claim 1  wherein said metal sheet is aluminum metal sheet having a thickness in the range of 0.08 to 0.2 inch.  
   
   
       3 . The method in accordance with  claim 1  wherein said core is comprised of heavy paper or a plastic material.  
   
   
       4 . The method in accordance with  claim 1  wherein said transition zone comprises 5 to 50% of the circumference of said core.  
   
   
       5 . The method in accordance with  claim 1  wherein said transition zone comprises 10 to 25% of the circumference of said core.  
   
   
       6 . The method in accordance with  claim 1  wherein said core has a crush strength of 15 to 25 psi.  
   
   
       7 . The method in accordance with  claim 1  wherein said stepped end has a depth in the range of 0.08 to 0.2 inch.  
   
   
       8 . The method in accordance with  claim 1  wherein said stepped end has a depth substantially equal to the thickness of sheet.  
   
   
       9 . A method of winding an aluminum metal sheet on a core to avoid formation of arbor deformities or lap marks, comprising the steps of: 
 (a) providing a source of metal sheet to be wound on a core;    (b) providing a core on which the metal sheet is to be wound, said core being generally cylindrical and having a circumference and an outside surface, said outside surface having: 
 a notch formed generally transverse to winding direction of said core, said notch having a stepped end and a tapered end disposed generally opposite said stepped end, said stepped end having a depth in the range of 0.08 to 0.2 inch to provide a bottom, said stepped end suited to having an end of said sheet abutted thereagainst, the tapered end extending from the bottom of said notch to said outside surface of said core to provide a transition zone having a length of 5 to 50% of said circumference, said core having crush strength of 15 to 25 psi;  
   (c) abutting an end of said sheet against the stepped end of said core; and    (d) winding said sheet on said core, said sheet being free of arbor deformities or lap marks after being wound on said core.    
   
   
       10 . A core for winding metal sheet thereon to provide the sheet metal free of lap marks upon unwinding, the core having a generally cylindrical configuration and having an outside surface, said outside surface having a wedge-shaped notch formed generally transverse to winding direction of the core, the notch having a stepped end and a tapered end disposed opposite the stepped end, the stepped end extending from the surface to a bottom, the stepped end having a tapered end extending from the bottom of stepped end to the outside surface of said core to provide a transition zone.  
   
   
       11 . The core in accordance with  claim 10  wherein said core is comprised of heavy paper.  
   
   
       12 . The core in accordance with  claim 10  wherein said transition zone comprises 5 to 50% of the circumference of said core.  
   
   
       13 . The core in accordance with  claim 10  wherein said transition zone comprises 10 to 25% of the circumference of said core.  
   
   
       14 . The core in accordance with  claim 10  wherein said core has a crush strength of 15 to 25 psi.  
   
   
       15 . The core in accordance with  claim 10  wherein said stepped end has a depth in the range of 0.08 to 0.2 inch.  
   
   
       16 . The core in accordance with  claim 10  wherein said transition zone is curved in the direction of winding.  
   
   
       17 . The core in accordance with  claim 10  wherein said stepped end has a depth substantially equal to the thickness of said sheet.