Tubular baseball bats with variable stiffened barrels

Abstract

Tubular baseball bats comprised of an elongated handle portion and a striking or barrel portion wherein the barrel portion has variable stiffness along its length. One such bat has a circumferential low cost, low weight stiffener generally located in the sweetspot area designed to increase radial stiffness in a controlled manner which results in decreasing the bat performance to meet a changed bat performance standard and can be applied at low cost to both used field returned bats and bats being newly manufactured. Further, new tubular polymer composite bats can be designed with increased radial stiffness generally located in the sweetspot area or with radial stiffness graduated from highest, generally in the sweetspot area, to lowest at the barrel ends. All bats of the present invention result in calculated bat performance to meet applicable regulatory standards while also increasing the sweetspot size.

1 . A tubular baseball bat comprising a cylindrical handle portion for gripping, a cylindrical tubular barrel portion for striking, and a tapered mid-section connecting said handle portion and said barrel portion, wherein said barrel portion has variable stiffness along its length.  
   
   
       2 . A bat according to  claim 1 , wherein said variable stiffness is achieved by adding a polymer composite material stiffener to the said barrel portion.  
   
   
       3 . A bat according to  claim 2  wherein said polymer composite material comprises a resin matrix encapsulating reinforcement fibers wherein said resin is selected from the group of resin consisting of epoxy, vinyl ester, polyester, urethane, nylon, and mixtures thereof and wherein said reinforcement fibers are selected from the group consisting fiberglass, graphite, carbon, aramid, boron, nylon and mixtures thereof.  
   
   
       4 . A bat according to  claim 2  wherein said stiffener has a length less than 50% of the said barrel portion length and adds less than 2 oz. to said bat weight.  
   
   
       5 . A bat according to  claim 2  wherein said stiffener is located internally, and/or externally to said barrel portion, and/or between members of double-walled or multi-walled bats, or combinations thereof.  
   
   
       6 . A bat according to  claim 2  wherein said stiffener is bonded full length to at least one bat barrel member.  
   
   
       7 . A bat according to  claim 1 , where said stiffness is radial stiffness.  
   
   
       8 . A polymer composite tubular baseball bat comprising a cylindrical handle portion for gripping, a cylindrical tubular barrel portion for striking, and a tapered mid-section connecting said handle portion and said barrel portion, wherein said barrel portion is radially stiffer in the middle of the said barrel portion and circumferentially less stiff radially in the two end portions of the said barrel portion.  
   
   
       9 . A bat according to  claim 8  wherein said polymer composite material comprises a resin matrix encapsulating reinforcement fibers wherein said resin is selected from the group of resin consisting of epoxy, vinyl ester, polyester, urethane, nylon, and mixtures thereof and wherein said reinforcement fibers are selected from the group consisting fiberglass, graphite, carbon, aramid, boron, nylon and mixtures thereof.  
   
   
       10 . A polymer composite baseball bat comprising a cylindrical handle portion for gripping, a cylindrical tubular barrel portion for striking, and a tapered mid-section connecting said handle and barrel portion, wherein the radial stiffness of said barrel portion is highest in the said barrel portion's middle area, lowest at the ends of the said barrel portion, and generally uniformly changes from the middle portion to each end portion of said barrel portion.  
   
   
       11 . A bat according to  claim 10  wherein a polymer composite material comprises a resin matrix encapsulating reinforcement fibers wherein said resin is selected from the group of resin consisting of epoxy, vinyl ester, polyester, urethane, nylon, and mixtures thereof and wherein said reinforcement fibers are selected from the group consisting fiberglass, graphite, carbon, aramid, boron, nylon and mixtures thereof.  
   
   
       12 . A tubular baseball bat comprising a cylindrical handle portion for gripping, a cylindrical tubular barrel portion for striking, and a tapered mid-section connecting said handle and barrel portion, wherein said barrel portion's thickness varies over said barrel portion's length.  
   
   
       13 . A bat according to  claim 12  wherein said barrel portion's thickness is at least 5% thinner, at either or both end portions of said barrel portion, than the central portion of said barrel portion.