Golf club shaft having wave shaped reinforced part

Abstract

The present invention relates to a golf club shaft having improved torsion characteristics comprising a base shaft having an internal surface and an external surface, and at least one wave shaped reinforced part on at least one of said surfaces, said wave shaped reinforced part comprising a plurality of reinforcement pieces. The wave shaped reinforced part is located on at least one of the upper portion, midpoint or lower portion. The golf club shafts of the present invention can be made by applying a base section of a prepreg sheet or assembly having a plurality of finger like elements to a portion of a base shaft, wrapping the finger like elements around the base shaft to provide a wave shaped reinforced part having a plurality of reinforcement pieces, and curing the shaft having the wave shaped reinforced part thereon to produce a golf club shaft having a wave shaped reinforced part. Golf clubs made with the shafts of the present invention impart greater flying distance and/or directional accuracy to golf balls struck by the golf clubs. The wave shaped reinforced part provides a means of moving the kick point of the shaft to achieve a desired effect on flying distance and/or accuracy. The present invention provides a convenient means of adjusting the characteristics of a golf club shaft according to the skill level of the intended user.

What is claimed is:  
     
         1 . A golf club shaft comprising a base shaft having an internal surface and an external surface, and at least one wave shaped reinforced part on at least one of said surfaces, said wave shaped reinforced part comprising a plurality of reinforcement pieces.  
     
     
         2 . The golf club shaft of  claim 1  wherein said golf club shaft includes an upper portion, a midpoint m, and a lower portion, said wave shaped reinforced part located on at least one of said upper portion, said midpoint m, and said lower portion.  
     
     
         3 . The golf club shaft of  claim 2  wherein said wave shaped reinforced part is located on said upper portion.  
     
     
         4 . The golf club shaft of  claim 2  wherein said wave shaped reinforced part is located on said lower portion.  
     
     
         5 . The golf club shaft  claim 2  wherein said wave shaped reinforced part is located on said midpoint m.  
     
     
         6 . The golf club shaft of  claim 1  wherein said plurality of reinforcement pieces is at least three reinforcement pieces.  
     
     
         7 . The golf club shaft of  claim 6  wherein said wave shaped reinforced part is on said external surface of said base shaft.  
     
     
         8 . The golf club shaft of  claim 7  wherein said wave shaped reinforced part has a length of about 2 cm to about 20 cm.  
     
     
         9 . The golf club shaft of  claim 8  wherein said wave shaped reinforced part has a sinusoidal configuration.  
     
     
         10 . The golf club shaft of  claim 1  wherein said reinforcement pieces comprise a carbon fiber prepreg sheet and a glass fiber prepreg sheet.  
     
     
         11 . A golf club shaft having an external surface, comprising a base shaft having a tip end for receiving a club head and a grip end for receiving a grip, and a wave shaped reinforced part on said external surface of said base shaft, wherein said wave shaped reinforced part has a length of about 20 cm and includes at least 3 reinforcement pieces, said wave shaped reinforced part having a sinusoidal configuration, and wherein said reinforcement pieces comprise carbon fiber prepreg.  
     
     
         12 . The golf club shaft of  claim 11  wherein said waved shaped reinforced part has at least 5 reinforcement pieces.  
     
     
         13 . The golf club shaft of  claim 11  wherein said reinforced part is located on said upper portion.  
     
     
         14 . The golf club shaft of  claim 11  wherein said base shaft has a length of about 1143 mm and a kickpoint located at about 44 cm from said tip end of said base shaft.  
     
     
         15 . The golf club shaft of  claim 11  wherein said reinforcement pieces further comprise glass fiber prepreg.  
     
     
         16 . A method of making a golf club shaft having a base shaft and a wave shaped reinforced part thereon comprising, 
 applying a base section  2 B of a prepreg sheet having a plurality of finger like elements  2 A to a portion of a base shaft,    wrapping said finger like elements  2 A around said base shaft to provide a wave shaped reinforced part having a plurality of reinforcement pieces on said base shaft, and    curing said shaft having said wave shaped reinforced part thereon to produce a golf club shaft having a wave shaped reinforced part thereon.    
     
     
         17 . The method of  claim 16  wherein said wave shaped reinforced part comprises at least 3 reinforced pieces.  
     
     
         18 . The method of  claim 16  wherein said base shaft has an upper portion, a midpoint m, and a lower portion, and wherein said wave shaped reinforced part is located on at least one of said upper portion, said midpoint m, and said lower portion.  
     
     
         19 . The method of  claim 16  wherein said prepreg sheet comprises a carbon fiber prepreg sheet.  
     
     
         20 . The method of  claim 16  wherein said prepreg sheet comprises a glass fiber prepreg sheet joined to a carbon fiber prepreg sheet.  
     
     
         21 . A golf club comprising a golf club shaft comprising a base shaft having an internal surface and an external surface, and at least one wave shaped reinforced part on at least one of said surfaces, said wave shaped reinforced part comprising 
 a plurality of reinforcement pieces.    
     
     
         22 . The golf club of  claim 21  wherein said golf club shaft includes an upper portion, a midpoint m, and a lower portion, said wave shaped reinforced part located on at least one of said upper portion, said midpoint m, and said lower portion.  
     
     
         23 . The golf club of  claim 22  wherein said wave shaped reinforced part is located on said upper portion.  
     
     
         24 . The golf club of  claim 22  wherein said wave shaped reinforced part is located on said lower portion.  
     
     
         25 . The golf club  claim 22  wherein said wave shaped reinforced part is located on said midpoint m.  
     
     
         26 . The golf club of  claim 21  wherein said plurality of reinforcement pieces is at least three reinforcement pieces.  
     
     
         27 . The golf club of  claim 26  wherein said wave shaped reinforced part is on said external surface of said tubular shaft member.  
     
     
         28 . The golf club of  claim 22  wherein said wave shaped reinforced part has a length of about 2 cm to about 15 cm.  
     
     
         29 . The golf club of  claim 28  wherein said wave shaped reinforced part has a sinusoidal configuration.  
     
     
         30 . The golf club of  claim 21  wherein said reinforcement pieces comprise a carbon fiber prepreg sheet and a glass fiber prepreg sheet.