Buffering structure for hollow and tubular sport items

Abstract

A hollow and tubular sport item includes a rectangular cross section which includes four corners and each corner includes a buffering structure. The buffering structure includes a recess which is enclosed by an inner wall and an outer wall of the corner. The recess can be empty or filled by Polyethylene (PE) or Polyurethane (PU).

1 . A hollow and tubular sport item comprising: 
 a rectangular cross section with four corners and each corner including a buffering structure, the buffering structure including a recess which is enclosed by an inner wall and an outer wall of the corner.    
   
   
       2 . The hollow tubular sport item as claimed in  claim 1 , wherein the inner wall of each corner is a curved wall which protrudes inward in an interior space of the sport item.  
   
   
       3 . The hollow tubular sport item as claimed in  claim 1 , wherein the inner wall of each corner is a straight wall which is inclined to two adjacent sides of the rectangular cross section.  
   
   
       4 . The hollow tubular sport item device as claimed in  claim 1 , wherein the recess in each corner is filled with Polyethylene (PE).  
   
   
       5 . The hollow tubular sport item device as claimed in  claim 1 , wherein the recess in each corner is filled with Polyurethane (PU).