Ball bat

Abstract

A ball bat is revealed. The ball bat includes a bat body made from metal. The bat body consists of a circular wall extended along a central axis thereof, a hollow space formed in the circular wall, and a plurality of ribs disposed axially and projecting from an inner surface of the circular wall toward the central axis of the bat body. Thus the inner surface of the circular wall is uneven. The hollow space is filled with foam to form a foam layer. By the arrangement of the foam layer and the uneven surface of the inner surface tightly connected to the foam layer, both the structural strength and the shock absorption of the ball bat are improved.

1 . A bat body comprising:
 a circular wall extended along a central axis thereof,   a hollow space formed in the circular wall, the hollow space being fully filled with foam to form a foam layer; and   a plurality of ribs disposed axially and projecting from an inner surface of the circular wall toward the central axis of the bat body so that the inner surface of the circular wall is uneven, the foam layer conforming to the uneven inner surface of the circular wall.   
     
     
         2 . The device as claimed in  claim 1 , wherein the foam is made from a material selecting from the group consisting of polystyrene, polypropylene, polyvinyl chloride, phenoplastics, and polyurethane. 
     
     
         3 . The device as claimed in  claim 2 , wherein a cross section of each rib is rectangular. 
     
     
         4 . The device as claimed in  claim 2 , wherein a cross section of each rib is serrated; an overall cross section of the ribs is formed by a plurality of notches and projections; each projection is formed by two corresponding slopes of the same serration extended and intersected while each notch is defined by two adjacent slopes of the two adjacent serrations and is an acute angle. 
     
     
         5 . The device as claimed in  claim 2 , wherein a cross section of each rib is jagged; an overall cross section of the ribs and the circular wall is formed by a plurality of notches and projections; each projection is formed by two corresponding slopes of the same serration extended and intersected while each notch is defined by two corresponding slopes of the two adjacent serrations and the inner surface of the circular wall therebetween. 
     
     
         6 . The device as claimed in  claim 1 , wherein adjacent ones of the ribs are arranged with the same angular spacing therebetween around the central axis of the bat body. 
     
     
         7 . The device as claimed in  claim 6 , wherein a cross section of each rib is rectangular. 
     
     
         8 . The device as claimed in  claim 6 , wherein a cross section of each rib is serrated; an overall cross section of the ribs is formed by a plurality of notches and projections; each projection is formed by two corresponding slopes of the same serration extended and intersected while each notch is defined by two adjacent slopes of the two adjacent serrations and is an acute angle. 
     
     
         9 . The device as claimed in  claim 6 , wherein a cross section of each rib is jagged; an overall cross section of the ribs and the circular wall is formed by a plurality of notches and projections; each projection is formed by two corresponding slopes of the same serration extended and intersected while each notch is defined by two corresponding slopes of the two adjacent serrations and the inner surface of the circular wall therebetween. 
     
     
         10 . The device as claimed in  claim 1 , wherein a cross section of each rib is rectangular. 
     
     
         11 . The device as claimed in  claim 1 , wherein a cross section of each rib is serrated; an overall cross section of the ribs is formed by a plurality of notches and projections; each projection is formed by two corresponding slopes of the same serration extended and intersected while each notch is defined by two adjacent slopes of the two adjacent serrations and is an acute angle. 
     
     
         12 . The device as claimed in  claim 1 , wherein a cross section of each rib is jagged; an overall cross section of the ribs and the circular wall is formed by a plurality of notches and projections; each projection is formed by two corresponding slopes of the same serration extended and intersected while each notch is defined by two corresponding slopes of the two adjacent serrations and the inner surface of the circular wall therebetween.