Shaft Structure with Configurable Bending, Weight, Moment-of-Inertia and Torque Profile

Abstract

A shaft structure with a configurable bending, weight, torque and moment-of-inertia profile is provided for golf clubs, fishing rods, and the like. The shaft structure employs an innovative inner and outer shaft structure. The golfer, in practice, configures the profile of a golf shaft by choosing from a plurality of different inner shaft structures each having a unique bending, weight, moment-of-inertia and torque profile. The inner shaft is securely fastened within the outer shaft. The combination of the inner shaft with the outer shaft results in an advantageous bending, weight, torque and moment-of-inertia profile. The golfer can, at any time and very easily, change the profile of the golf shaft according to their physical, course and weather conditions for any given day.

1 . A configurable shaft structure, comprising an outer shaft structure and an interchangeable inner shaft structure; said interchangeable inner shaft structure being detachably connected to said outer shaft structure. 
   
   
       2 . The shaft structure as in  claim 1 , wherein said interchangeable inner shaft structure includes a characteristic of a stiffness. 
   
   
       3 . The shaft structure as in  claim 2 , wherein said stiffness of said interchangeable inner shaft structure varies along the longitudinal axis of said interchangeable inner shaft structure. 
   
   
       4 . The shaft structure as in  claim 1 , wherein said interchangeable inner shaft structure includes a characteristic of a weight. 
   
   
       5 . The shaft structure as in  claim 4 , wherein said weight of said interchangeable inner shaft structure varies along the longitudinal axis of said interchangeable inner shaft structure. 
   
   
       6 . The shaft structure as in  claim 1 , wherein said interchangeable inner shaft structure includes a characteristic of a torsional rigidity about the longitudinal axis. 
   
   
       7 . The shaft structure as in  claim 6 , wherein said torsional rigidity of said interchangeable inner shaft structure varies along the longitudinal axis of said interchangeable inner shaft structure. 
   
   
       8 . A configurable shaft structure as in  claim 1 , wherein said interchangeable inner shaft structure includes a male coupling device and said outer shaft section includes a female coupling device wherein said female coupling device receives said male coupling device in mechanical cooperation to mechanically convey rotational motion thereof. 
   
   
       9 . A configurable shaft structure as in  claim 8 , wherein said male coupling device and said female coupling device include a locking mechanism. 
   
   
       10 . A modifiable shaft structure, comprising an outer shaft structure and a plurality of interchangeable inner shaft structures; wherein at least one said interchangeable inner shaft structure being in mechanical cooperation with said outer shaft structure whereby the loading of said outer shaft structure transfers same said loading upon said interchangeable inner shaft structure such that the combination of resistance to said loading is generated from the reaction of said outer shaft structure and said interchangeable inner shaft structure to said loading; whereby the weight of said modifiable shaft structure is derived from the weight of said outer shaft structure and the weight of said interchangeable inner shaft structure in aggregate; whereby the distribution of weight of said modifiable shaft structure is derived from the distribution of weight of said outer shaft structure and the distribution of weight of said interchangeable inner shaft structure in aggregate; whereby the torsional rigidity about the longitudinal axis of said modifiable shaft structure is derived from the torsional rigidity of said outer shaft structure and torsional rigidity of said interchangeable inner shaft structure in aggregate; each said interchangeable inner shaft structure comprising a stiffness, weight, distribution of weight and torsional rigidity wherein the stiffness, weight, distribution of weight and torsional rigidity may vary.