Abutment joint for paper reel cores

Abstract

An abutment joint for end-to-end joining of paper reel cores, the abutment joint comprising a first conical surface ( 4 ) formed on the outer surface of one core ( 2 ) and a second conical surface ( 3 ) formed on the inner surface of the other core ( 1 ), whereby said first conical surface and said second conical surface abut against each other in the joint, wherein at least one protrusion ( 6 ) is formed at least on one conical surface and at least one groove ( 5 ) is formed at least on the other conical surface to form an interlocking joint between the cores.

1 . An abutment joint for end-to-end joining of paper reel cores, the abutment joint comprising a first conical surface ( 4 ) formed on the outer surface of one core ( 2 ) and a second conical surface ( 3 ) formed on the inner surface of the other core ( 1 ), whereby said first conical surface and said second conical surface abut against each other in the joint, at least one protrusion ( 6 ) is formed at least on one conical surface, and at least one groove ( 5 ) is formed at least on the other conical surface to form an interlocking joint between the cores.  
   
   
       2 . The abutment joint according to  claim 1 , wherein the protrusion ( 6 ) is formed on the conical surface ( 4 ) formed on the outer surface of the core ( 2 ) and the groove ( 5 ) is formed on the conical surface ( 3 ) formed on the inner surface of the core ( 1 ).  
   
   
       3 . The abutment joint according to  claim 1 , wherein the protrusion ( 6 ) is formed to the end of the core.  
   
   
       4 . The abutment joint according to  claim 1 , wherein glue is applied on the conical surface ( 3 ,  4 ) of at least one of the cores.  
   
   
       5 . The abutment joint according to  claim 2 , wherein the protrusion ( 6 ) is formed to the end of the core.  
   
   
       6 . The abutment joint according to  claim 2 , wherein glue is applied on the conical surface ( 3 ,  4 ) of at least one of the cores.  
   
   
       7 . The abutment joint according to  claim 3 , wherein glue is applied on the conical surface ( 3 ,  4 ) of at least one of the cores.  
   
   
       8 . The abutment joint according to  claim 5 , wherein glue is applied on the conical surface ( 3 ,  4 ) of at least one of the cores.