Golf club shaft

Abstract

A golf club shaft ( 10 ) composed of a metal tube and having a weight not less than 50 g and less than 85 g. A rib ( 21 ) is formed on an inner peripheral surface of the golf club shaft ( 10 ) and/or a peripheral surface thereof. A rigidity value (EI value) of the golf club shaft ( 10 ) at a position spaced at 90 mm from a head-side front end ( 12 ) thereof is set to not less than 1.0 kg·mm 2 nor more than 2.5 kg·mm 2 . An outer diameter (D 1 ) of the golf club shaft ( 10 ) at a position spaced at 30 mm from the head-side front end ( 12 ) thereof is set to not less than 9.5 mm nor more than 15.0 mm.

1 . A golf club shaft composed of a metal tube and having a weight not less than 50 g and less than 85 g, wherein a rib is formed on an inner peripheral surface of said golf club shaft and/or a peripheral surface thereof; 
 a rigidity value of said golf club shaft at a position spaced at 90 mm from a head-side front end thereof is set to not less than 1.0 kg·mm 2  nor more than 2.5 kg·mm 2 ; and    an outer diameter of said golf club shaft at a position spaced at 30 mm from said head-side front end thereof is set to not less than 9.5 mm nor more than 15.0 mm.    
   
   
       2 . The golf club shaft according to  claim 1 , wherein said rib is projected from an inner peripheral surface of said golf club shaft in such a way that at least one portion of said rib is formed in a region ranging from said head-side front end of said shaft to a position spaced at 200 mm from said head-side front end; or said rib is formed in at least one portion of said region.  
   
   
       3 . The golf club shaft according to  claim 1 , wherein said rib is formed evenly over a full length of a circumference of said golf club shaft; and 
 said rib is configured as a meshed rib by intersecting with each other a spiral rib inclined in a plus direction with respect to an axis of said shaft and a spiral rib inclined in a minus direction with respect to said axis of said shaft; as a honeycomb rib formed by continuously arranging polygonally framed ribs; as a latticed rib formed by intersecting ribs extended in parallel with said axial direction of said shaft with ribs extended orthogonally to said axial direction thereof; as a rib formed by continuously arranging triangularly framed ribs, one side of each of which is composed of a rib orthogonal to said axial direction of said shaft, and as a rib formed by continuously arranging rhombically framed ribs each having a diagonal rib extended in said axial direction of said shaft and another diagonal rib extended orthogonally to said axial direction thereof.    
   
   
       4 . The golf club shaft according to  claim 2 , wherein said rib is formed evenly over a full length of a circumference of said golf club shaft; and 
 said rib is configured as a meshed rib by intersecting with each other a spiral rib inclined in a plus direction with respect to an axis of said shaft and a spiral rib inclined in a minus direction with respect to said axis of said shaft; as a honeycomb rib formed by continuously arranging polygonally framed ribs; as a latticed rib formed by intersecting ribs extended in parallel with said axial direction of said shaft with ribs extended orthogonally to said axial direction thereof; as a rib formed by continuously arranging triangularly framed ribs, one side of each of which is composed of a rib orthogonal to said axial direction of said shaft, and as a rib formed by continuously arranging rhombically framed ribs each having a diagonal rib extended in said axial direction of said shaft and another diagonal rib extended orthogonally to said axial direction thereof.    
   
   
       5 . A golf club shaft composed of a metal tube and having a weight of not less than 50 g and less than 85 g, 
 wherein a rib is formed on an inner peripheral surface of said golf club shaft and/or a peripheral surface thereof; and    at least one portion of said rib is formed in a region ranging from a grip-side rear end of said shaft to a position spaced at an interval corresponding to not less than 30% nor more than 40% of a full length of said shaft or in a portion of said region including a position spaced at an interval corresponding to 35% of said full length of said shaft from said grip-side rear end; and    a rigidity value of said region is set to not less than 3.5 kg·mm 2  nor more than 8.0 kg·mm 2 .    
   
   
       6 . The golf club shaft according to  claim 1 , wherein a projected height of said rib is set to 0.1 mm to 11.0 mm; and a width thereof is set to 0.1 mm to 11.0 mm.  
   
   
       7 . The golf club shaft according to  claim 2 , wherein a projected height of said rib is set to 0.1 mm to 11.0 mm; and a width thereof is set to 0.1 mm to 11.0 mm.  
   
   
       8 . The golf club shaft according to  claim 3 , wherein a projected height of said rib is set to 0.1 mm to 11.0 mm; and a width thereof is set to 0.1 mm to 11.0 mm.  
   
   
       9 . The golf club shaft according to  claim 4 , wherein a projected height of said rib is set to 0.1 mm to 11.0 mm; and a width thereof is set to 0.1 mm to 11.0 mm.  
   
   
       10 . The golf club shaft according to  claim 5 , wherein a projected height of said rib is set to 0.1 mm to 11.0 mm; and a width thereof is set to 0.1 mm to 11.0 mm.  
   
   
       11 . The golf club shaft according to  claim 1 , wherein a metal belt-like member having said rib formed by press molding on an inner peripheral surface thereof and/or a peripheral surface thereof is wound tubularly, and mating portions of said belt-like member are welded to each other to form said metal tube.  
   
   
       12 . The golf club shaft according to  claim 2 , wherein a metal belt-like member having said rib formed by press molding on an inner peripheral surface thereof and/or a peripheral surface thereof is wound tubularly, and mating portions of said belt-like member are welded to each other to form said metal tube.  
   
   
       13 . The golf club shaft according to  claim 3 , wherein a metal belt-like member having said rib formed by press molding on an inner peripheral surface thereof and/or a peripheral surface thereof is wound tubularly, and mating portions of said belt-like member are welded to each other to form said metal tube.  
   
   
       14 . The golf club shaft according to  claim 4 , wherein a metal belt-like member having said rib formed by press molding on an inner peripheral surface thereof and/or a peripheral surface thereof is wound tubularly, and mating portions of said belt-like member are welded to each other to form said metal tube.  
   
   
       15 . The golf club shaft according to  claim 5 , wherein a metal belt-like member having said rib formed by press molding on an inner peripheral surface thereof and/or a peripheral surface thereof is wound tubularly, and mating portions of said belt-like member are welded to each other to form said metal tube.  
   
   
       16 . The golf club shaft according to  claim 6 , wherein a metal belt-like member having said rib formed by press molding on an inner peripheral surface thereof and/or a peripheral surface thereof is wound tubularly, and mating portions of said belt-like member are welded to each other to form said metal tube.