Ball bats with reinforcing inserts

Abstract

A ball bat includes a cylindrical barrel portion surrounding a tubular insert. The tubular insert comprises a thermoplastic material. The length, diameter, wall thickness, position and weight of the insert may be controlled in order to improve performance of the ball bat.

What is claimed is: 
     
         1 . A ball bat comprising:
 a cylindrical barrel portion having an inner surface; and   a tubular insert inside the cylindrical barrel portion having a cylindrical outer surface,   wherein the tubular insert comprises a thermoplastic material having a tensile strength above 5,000 psi.   
     
     
         2 . The ball bat according to  claim 1 , wherein the cylindrical outer surface of the tubular insert is in contact with the inner surface of the cylindrical barrel portion. 
     
     
         3 . The ball bat according to  claim 2 , wherein the tubular insert is adhesively bonded to the cylindrical barrel portion. 
     
     
         4 . The ball bat according to  claim 2 , wherein the cylindrical outer surface of the tubular insert is friction fit or press fit against the inner surface of the cylindrical barrel portion. 
     
     
         5 . The ball bat according to  claim 1 , wherein the cylindrical outer surface of the tubular insert is spaced from the inner surface of the cylindrical barrel portion to form a gap therebetween. 
     
     
         6 . The ball bat according to  claim 5 , wherein the gap is from 0.001 to 0.1 inch. 
     
     
         7 . The ball bat according to  claim 1 , wherein the tubular insert weighs from 1 to 10 ounces. 
     
     
         8 . The ball bat according to  claim 1 , wherein the thermoplastic material has a compressive strength above 10,000 psi. 
     
     
         9 . The ball bat according to  claim 1 , wherein the thermoplastic material comprises one or more thermoplastic materials chosen from polyvinylidene fluoride, polytetrafluoroethylene, ethylene-chlorotrifluoroethylene, fluorinated ethylene propylene, polybutylene terephthalate, polychlorotrifluoroethylene, perfluoroalkoxy, polyphenylene sulfide, polyetheretherketone, acetal, polyethylene terephthalate, ultra high molecular weight polyethylene, high density polyethylene, low density polyethylene, polypropylene, polymethylpentene, polysulfone, polyetherimide, polyethersulfone, polyarylsulfone, polyarylethersulfone, polycarbonate, polyphenylene oxide, polyphenylene ether, thermoplastic polyurethane, acrylic, polystyrene, acrylonitrile butadiene styrene, polyvinyl chloride, polyethylene terephthalate glycol, cellulose acetate butyrate, polyamide, polyhydroxyalkanoate, polyhydroxybutyrate, polyethylene adipate, polybutylene succinate, polyalkylene terephthalates, polytrimethylene terephthalate, polypropylene terephthalate, polyethylene naphthalate and combinations thereof. 
     
     
         10 . The ball bat according to  claim 1 , wherein the thermoplastic material comprises polybutylene terephthalate. 
     
     
         11 . The ball bat according to  claim 1 , wherein the thermoplastic material comprises a polyamide. 
     
     
         12 . The ball bat according to  claim 1 , wherein the thermoplastic material comprises nylon. 
     
     
         13 . The ball bat according to  claim 1 , wherein the thermoplastic material further comprises one or more additional thermoplastic materials, and the weight ratio of the thermoplastic material to the one or more additional thermoplastic materials is from 1:1 to 50:1. 
     
     
         14 . The ball bat according to  claim 1 , wherein the thermoplastic material is non-reinforced. 
     
     
         15 . The ball bat according to  claim 1 , wherein the thermoplastic material is reinforced with a reinforcing material comprising glass fibers, glass beads, carbon fibers, or combinations thereof. 
     
     
         16 . The ball bat according to  claim 1 , wherein the thermoplastic material is reinforced with a discontinuous reinforcing material that is present in an amount of from 5 to 60 weight percent, based on a total weight of the tubular insert. 
     
     
         17 . The ball bat according to  claim 1 , wherein the tubular insert has a wall thickness of greater than 0.04 inch. 
     
     
         18 . The ball bat according to  claim 1 , wherein the tubular insert has a wall thickness of from 0.05 to 0.5 inch. 
     
     
         19 . The ball bat according to  claim 1 , wherein the tubular insert has a substantially constant wall thickness along an axial length of the tubular insert. 
     
     
         20 . The ball bat according to  claim 1 , wherein the tubular insert has a substantially uniform inner diameter along an axial length of the tubular insert. 
     
     
         21 . The ball bat according to  claim 1 , wherein the tubular insert has a substantially uniform outer diameter along an axial length of the tubular insert. 
     
     
         22 . The ball bat according to  claim 1 , wherein the tubular insert has a length of from 1 to 99 percent of the total length of the cylindrical barrel portion. 
     
     
         23 . The ball bat according to  claim 1 , wherein the tubular insert has a length of from 30 to 80 percent of the total length of the cylindrical barrel portion. 
     
     
         24 . The ball bat according to  claim 1 , wherein the tubular insert comprises multiple layers of the thermoplastic material, and each layer has a wall thickness of from 0.001 to 0.1 inch. 
     
     
         25 . The ball bat according to  claim 1 , wherein the cylindrical barrel portion comprises a composite material comprising a carbon fiber reinforced resin. 
     
     
         26 . The ball bat according to  claim 25 , wherein the carbon fiber reinforced resin comprises an epoxy resin. 
     
     
         27 . The ball bat according to  claim 1 , further comprising a thermoplastic material protective layer over at least a portion of the outer surface of the cylindrical barrel portion. 
     
     
         28 . The ball bat according to  claim 1 , further comprising a tapered neck portion interconnecting the cylindrical barrel portion to a handle portion, wherein the tapered neck portion decreases in diameter in a direction toward the handle portion, and wherein the tubular insert does not extend into the tapered neck portion or the handle portion. 
     
     
         29 . The ball bat according to  claim 1 , wherein the ball bat comprises a baseball bat or a softball bat.