Bat with foam core insert

Abstract

A composite ball bat comprising a handle, a tapered portion extending from an attachment end of the handle, and a barrel portion extending from the tapered portion to an end-cap end is provided. The barrel portion includes an inner surface and an outer surface. A foam core insert is preferably located within the barrel portion so that it is friction fit within the inner surface of the bat. The specific strength of the foam core insert may be 40 kNm/kg or more, and the specific modulus of the foam core insert may be at least 1,000 kNm/kg. The foam core insert is preferably less than 0.5 g/cc and preferably has a compressive strength greater than 16,500 kPa.

What is claimed is: 
     
         1 . A ball bat comprising:
 a handle having a knob end and an attachment end;   a tapered portion extending from the attachment end of the handle;   a barrel portion extending from the tapered portion to an end-cap end, wherein said barrel portion includes:
 an inner surface; 
 an outer surface; and 
 a foam core insert secured within the inner surface of the barrel portion, wherein the foam core insert has a specific strength of 40 kNm/kg or more. 
   
     
     
         2 . The ball bat of  claim 1 , wherein the foam core insert has a specific modulus of at least 1,000 kNm/kg. 
     
     
         3 . The ball bat of  claim 1 , wherein the density of the foam core insert is less than 0.5 g/cc. 
     
     
         4 . The ball bat of  claim 1 , wherein the foam core insert is made of at least one of a polyurethane foam and a polymethacrylimide foam. 
     
     
         5 . The ball bat of  claim 1 , wherein the foam core insert is secured in the barrel portion by an adhesive. 
     
     
         6 . A ball bat comprising:
 a handle having a knob end and an attachment end;   a tapered portion extending from the attachment end of the handle;   a barrel portion extending from the tapered portion to an end-cap end, wherein said barrel portion includes:
 an inner surface; 
 an outer surface; and 
 a foam core insert secured within the inner surface of the barrel portion, wherein the foam core insert has a specific modulus of at least 1,000 kNm/kg. 
   
     
     
         7 . The ball bat of  claim 6 , wherein the foam core insert has a specific strength of 40 kNm/kg or more. 
     
     
         8 . The ball bat of  claim 6 , wherein the density of the foam core insert is less than 0.5 g/cc. 
     
     
         9 . The ball bat of  claim 6 , wherein the foam core insert is made of at least one of a polyurethane foam and a polymethacrylimide foam. 
     
     
         10 . The ball bat of  claim 7 , wherein the foam core insert is secured in the barrel portion by an adhesive. 
     
     
         11 . A ball bat comprising:
 a handle having a knob end and an attachment end;   a tapered portion extending from the attachment end of the handle;   a barrel portion extending from the tapered portion to an end-cap end, wherein said barrel portion includes:
 an inner surface; 
 an outer surface; and 
 a foam core insert secured within the inner surface of the barrel portion, wherein the density of the foam core insert is less than 0.5 g/cc. 
   
     
     
         12 . The ball bat of  claim 11 , wherein the foam core insert has a specific strength of 40 kNm/kg or more. 
     
     
         13 . The ball bat of  claim 11 , wherein the foam core insert has a specific modulus of at least 1,000 kNm/kg. 
     
     
         14 . The ball bat of  claim 11 , wherein the foam core insert is made of at least one of a polyurethane foam and a polymethacrylimide foam. 
     
     
         15 . The ball bat of  claim 14 , wherein the foam core insert is secured in the barrel portion by an adhesive.