Shaft for golf club

Abstract

There is provided a golf club shaft in which the shaft is properly flexed at the time of swing and an excessive deformation of the shaft is restricted at the time of impact, a high repelling force is generated, and thereby an initial speed of the ball and the carry of the ball are further improved and which is quite suitable for using a club head having a low center of gravity or a large sized club head. This golf club shaft is filled with the resilient material having a feature in which a rapid application of force against the entire inner part of the hollow shaft or its extremity end causes a high repelling force to be acted on to cause it to be hardly deformed and in turn a gradual application of force causes itself to be easily deformed.

What is claimed:  
     
         1 . A golf club shaft in which an entire inner region of a hollow shaft is filled with resilient material having a feature in which a rapid application of force causes a high repelling force to be acted on it to be hardly deformed and in turn a gradual application of force causes the shaft to be easily deformed, wherein a core rod is stored within the shaft along its axis, a lower end of said core rod is fixed to the extremity end of the shaft and the core rod is inserted into said resilient material.  
     
     
         2 . A golf club shaft according to  claim 1  in which the core rod and said resilient material is adhered and fixed.  
     
     
         3 . A golf club shaft according to  claim 2  in which an upper end of the resilient material is adhered to and fixed to the shaft.  
     
     
         4 . A golf club shaft according to  claim 1  in which the resilient material is adhered and fixed to the shaft.  
     
     
         5 . A golf club shaft according to  claim 2  in which the resilient material is adhered and fixed to the shaft.  
     
     
         6 . A golf club shaft according to  claim 1  in which an upper end of the resilient material is adhered to and fixed to the shaft.  
     
     
         7 . A golf club shaft in the form of a hollow shaft that is at least partially filled with a resilient material that has a feature in which a rapid application of a force at an inner extremity end of the hollow shaft causes a high repelling to be acted on it and causes it to be hardly deformed and in turn a gradual application of force at the inner extremity end of the hollow shaft causes the material to be easily deformed, wherein the range of the extremity end of the hollow shaft where the resilient material is filled is from 30 cm to 40 cm from a neck end or from near an end part.  
     
     
         8 . A golf club shaft according to  claim 7  in which a core rod is stored within the shaft along its axis, a lower end of said core rod is fixed to the extremity end of the shaft and the core rod is inserted into said resilient material.  
     
     
         9 . A golf club shaft according to  claim 7  in which the core rod and said resilient material is adhered and fixed.  
     
     
         10 . A golf club shaft according to  claim 8  in which the core rod and said resilient material is adhered and fixed.  
     
     
         11 . A golf club shaft according to  claim 7  in which the resilient material is adhered and fixed to the shaft.  
     
     
         12 . A golf club shaft according to  claim 8  in which the resilient material is adhered and fixed to the shaft.  
     
     
         13 . A golf club shaft according to  claim 10  in which the resilient material is adhered and fixed to the shaft.  
     
     
         14 . A golf club shaft according to  claim 7  in which an upper end of the resilient material is adhered to and fixed to the shaft.  
     
     
         15 . A golf club shaft according to  claim 8  in which an upper end of the resilient material is adhered to and fixed to the shaft.  
     
     
         16 . A golf club shaft according to  claim 10  in which an upper end of the resilient material is adhered to and fixed to the shaft.