Low torque composite golf shaft

Abstract

A golf shaft is provided having a tip portion and a butt portion. The shaft includes a first torsionally resistant flag extending along the entire length of the shaft. The shaft also includes a second torsionally resistant flag which only extends over the tip portion of the shaft. In this way, the tip portion of the shaft includes two torsionally resistant flags for providing enhanced torsion resistance without negatively impacting the bending stiffness or weight of the overall shaft.

What is claimed is:  
     
         1 . A shaft comprising: 
 a plurality of layers of material, each layer of material including a plurality of fibers in a pre-selected orientation, the plurality of layers including: 
 a first layer of material including at least two sets of fibers arranged at an angle with respect to each other and extending along a first prescribed length of the shaft; and  
 a second layer of material including at least two sets of fibers arranged at an angle with respect to each other and extending along a second prescribed length of the shaft, the second prescribed length of the shaft being shorter than the first prescribed length and including a tip end of the shaft.  
   
     
     
         2 . The shaft of  claim 1  wherein each of said first and second layers of material further comprises: 
 a first set of parallel fibers aligned at about a +45 degree angle relative to the longitudinal axis of the shaft; and  
 a second set of parallel fibers aligned at about a −45 degree angle relative to the longitudinal axis of the shaft.  
 
     
     
         3 . The shaft of  claim 1  wherein the plurality of layers of material further includes: 
 a third layer of material including a plurality of parallel fibers aligned axially relative to a longitudinal axis of the shaft.  
 
     
     
         4 . The shaft of  claim 3  wherein the plurality of layers of material further includes: 
 a fourth layer of material including a plurality of parallel fibers aligned perpendicularly relative to the longitudinal axis of the shaft.  
 
     
     
         5 . The shaft of  claim 4  wherein each of said first and second layers of material further comprises: 
 a first set of parallel fibers aligned at about a +45 degree angle relative to the longitudinal axis of the shaft; and  
 a second set of parallel fibers aligned at about a −45 degree angle relative to the longitudinal axis of the shaft.  
 
     
     
         6 . A shaft comprising: 
 a plurality of layers of material, each layer including a plurality of fibers in a pre-selected orientation, the plurality of layers including: 
 at least one bend stiffening layer of material including a plurality of parallel fibers aligned along a longitudinal axis of the shaft;  
 at least one crush resistant layer of material including a plurality of parallel fibers aligned perpendicular to the longitudinal axis of the shaft; and  
 two torsion resistant layers of material, each torsion resistant layer including a first set of parallel fibers aligned at a first angle relative to the longitudinal axis of the shaft and a second set of parallel fibers aligned at a second angle relative to the longitudinal axis of the shaft and crossing the first set of parallel fibers.  
   
     
     
         7 . The shaft of  claim 6  wherein one of the at least two torsion resistant layers of material is located over a sub-portion of the shaft, the sub-portion including a tip section of the shaft.  
     
     
         8 . The shaft of  claim 6  wherein: 
 said first angle is about +45 degrees relative to the longitudinal axis of the shaft; and  
 said second angle is about −45 degrees relative to the longitudinal axis of the shaft.  
 
     
     
         9 . A shaft comprising: 
 a composite material including a plurality of fibers dispersed therein in pre-selected orientations, the plurality of fibers including: 
 a first layer of biased fibers extending along a first prescribed length of the shaft;  
 a second layer of biased fibers extending along a second prescribed length of the shaft, the second prescribed length of the shaft being shorter than the first prescribed length and including a tip section of the shaft.  
   
     
     
         10 . The shaft of  claim 9  wherein each of said first and second layers of biased fibers further comprises: 
 a first set of parallel fibers aligned at about a +45 degree angle relative to a longitudinal axis of the shaft; and  
 a second set of parallel fibers aligned at about a −45 degree angle relative to the longitudinal axis of the shaft.  
 
     
     
         11 . The shaft of  claim 9  wherein said plurality of fibers further includes: 
 a first set of parallel fibers aligned axially relative to a longitudinal axis of the shaft.  
 
     
     
         12 . The shaft of  claim 11  wherein the plurality of fibers further includes: 
 a second set of parallel fibers aligned perpendicularly relative to the longitudinal axis of the shaft.  
 
     
     
         13 . A method of making a shaft comprising: 
 wrapping a plurality of layers of material over a mandrel, each layer of material including a plurality of fibers dispersed in an uncured plastic in a preselected orientation;    processing the uncured plastic to form a unitized structure; and    removing the mandrel;    wherein the wrapping step includes: 
 wrapping a first layer of material along a first prescribed length of the mandrel, the first layer of material including at least two sets of fibers arranged at an angle with respect to each other; and  
 wrapping a second layer of material along a second prescribed length of the mandrel, the second layer of material including at least two sets of fibers arranged at an angle with respect to each other, the second prescribed length of the mandrel being shorter than the first prescribed length and including a tip section of the mandrel.  
   
     
     
         14 . The method of  claim 13  wherein each of said first and second layers of material further comprises: 
 a first set of parallel fibers aligned at about a +45 degree angle relative to the longitudinal axis of the mandrel; and  
 a second set of parallel fibers aligned at about a −45 degree angle relative to the longitudinal axis of the mandrel.  
 
     
     
         15 . The method of  claim 13  wherein the wrapping step further includes: 
 wrapping a third layer of material around the mandrel, the third layer of material including a plurality of parallel fibers aligned axially relative to a longitudinal axis of the mandrel.  
 
     
     
         16 . The shaft of  claim 15  wherein the wrapping step further includes: 
 wrapping a fourth layer of material around the mandrel, the fourth layer of material including a plurality of parallel fibers aligned perpendicularly relative to the longitudinal axis of the mandrel.  
 
     
     
         17 . The shaft of  claim 16  wherein said first and second layers of material further comprises: 
 a first set of parallel fibers aligned at about a +45 degree angle relative to the longitudinal axis of the mandrel; and  
 a second set of parallel fibers aligned at about a −45 degree angle relative to the longitudinal axis of the mandrel.  
 
     
     
         18 . A method of making a shaft comprising: 
 wrapping at least one bend stiffening flag of material around a mandrel, the at least one bend stiffening flag of material including a plurality of parallel fibers dispersed in an uncured plastic and aligned along a longitudinal axis of the mandrel;    wrapping at least one crush resistant flag of material around the mandrel, the at least one crush resistant flag of material including a plurality of parallel fibers dispersed in an uncured plastic and aligned perpendicular to the longitudinal axis of the mandrel;    wrapping two torsion resistant flags of material around the mandrel, each of the two torsion resistant flags including a first set of parallel fibers aligned at a first angle relative to the longitudinal axis of the mandrel and a second set of parallel fibers aligned at a second angle relative to the longitudinal axis of the mandrel and crossing the first set of parallel fibers;    processing the uncured plastic to form a unitized structure; and    removing the mandrel.    
     
     
         19 . The method of  claim 18  wherein said step of wrapping two torsion resistant flags of material around the mandrel further comprises wrapping one of said two torsion resistant flags around a sub-portion of the mandrel, the sub-portion including a tip section of the mandrel.  
     
     
         20 . The method of  claim 18  wherein: 
 said first angle is about +45 degrees relative to the longitudinal axis of the mandrel; and  
 said second angle is about −45 degrees relative to the longitudinal axis of the mandrel.  
 
     
     
         21 . A method of making a shaft comprising: 
 depositing a composite material over a mandrel, the composite material including a plurality of fibers dispersed in an uncured plastic in pre-selected orientations;    processing the uncured plastic to form a unitized structure; and    removing the mandrel;    wherein said depositing step includes: 
 depositing a first layer of biased fibers along a first prescribed length of the mandrel; and  
 depositing a second layer of biased fibers along a second prescribed length of the mandrel, the second prescribed length of the mandrel being shorter than the first prescribed length and including a tip section of the mandrel.  
   
     
     
         22 . The shaft of  claim 21  wherein each of said first and second layers of biased fibers further comprises: 
 a first set of parallel fibers aligned at about a +45 degree angle relative to a longitudinal axis of the mandrel; and  
 a second set of parallel fibers aligned at about a −45 degree angle relative to the longitudinal axis of the mandrel.  
 
     
     
         23 . The method of  claim 21  wherein said depositing step further includes: 
 depositing a first set of parallel fibers along the mandrel, the first set of parallel fibers being aligned axially relative to a longitudinal axis of the mandrel.  
 
     
     
         24 . The method of  claim 23  wherein said depositing step further includes: 
 depositing a second set of parallel fibers along the mandrel, the second set of parallel fibers being aligned perpendicularly relative to the longitudinal axis of the mandrel.