Abstract:
A golf club shaft adaptor includes a cylindrical hollow body having side walls with at least one aperture therein. The cylindrical hollow body is sized and dimensioned to be retained within the hosel of a golf club head and to retain within the golf club adaptor the distal end of a golf club shaft. The golf club adaptor is adapted with respect to its configuration and material so that it will not do damage to a golf club shaft or to a golf club head during use of the golf club.

Description:
FIELD OF THE INVENTION 
   This invention relates generally to golf clubs and, more specifically, to the retrofitting of shafts to different size golf club heads. 
   BACKGROUND OF THE INVENTION 
   A golf club wood typically comprises a head portion and a shaft portion. The shaft is affixed to the head by inserting the distal end of the shaft into a hole in the head. The hole in the head is commonly termed a “hosel.” 
   It is not uncommon for a golfer, especially a skilled golfer, to retrofit the golfer&#39;s woods or irons with golf club shafts having a thinner diameter than the existing golf club shafts. To accomplish this, a skilled craftsman removes the distal end of each golf club shaft from the hosel in each golf head. The craftsman then reinserts a new shaft having a thinner diameter into each of the hosels. Because each new shaft has a lesser outer diameter than the inner diameter of its hosel, the craftsman generally has to interpose an adaptor, metal sleeve, shim or metal spring between the distal end of the shaft and the hosel. The craftsman then attempts to secure the shaft and adaptor within the hosel with a liquid adhesive. 
   Typically, the craftsman finds it difficult to rigidly secure the distal end of the shaft and the adaptor into the hosel. This is because the craftsman finds it difficult to thoroughly disperse the liquid adhesive to all surfaces of the shaft, adaptor and hosel. This is also true with respect to metal sleeves and shims. Metal coil springs having spacing between the coils of the spring have been tried as a golf club shaft adaptors. However, the sharpness of the coils and the hardness of the coils tends to cause the coil to cut into the golf club shaft during use of the golf club. This, in turn, leads to the premature failure of the golf club. Also, a spring will often collapse during the insertion of the shaft into the hosel, and this too may lead to the premature failure of the golf club. 
   Accordingly, there is a need for a solution to this problem in the prior art. 
   SUMMARY OF THE INVENTION 
   The invention satisfies this need. The invention is a golf club adaptor comprising a cylindrical hollow body having side walls, a first end, a second end, an outer diameter and an inner diameter. The side walls have an internal surface, and external surface and at least one aperture. The golf club adaptor is sized and dimensioned to facilitate the attachment of the distal end of a golf club shaft into the hosel of a golf club head, wherein the outer diameter of the golf club shaft is less than the diameter of the hosel. 

   
     DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims and accompanying drawings where: 
       FIG. 1  is a perspective view of a golf club adaptor having features of the invention; 
       FIG. 2  is a perspective view of a golf club assembly having features of the invention; 
       FIG. 3  is an exploded perspective view of the golf club assembly illustrated in  FIG. 2 ; 
       FIG. 4  is a second perspective view of the golf club adaptor illustrated in  FIG. 1 ; and 
       FIG. 5  is a cross-sectional view of the golf club adaptor taken along line  5 — 5 . 
   

   DETAILED DESCRIPTION 
   The following discussion describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well. 
   The invention is a golf club shaft adaptor  10  as illustrated in  FIGS. 1 ,  4  and  5 . The shaft adaptor  10  can be used to conveniently attach the shaft  12  to a golf club  14  to a golf club head  16  having a hosel  18 , wherein the distal end  20  of the golf club shaft  12  has a diameter which is less than the diameter of the hosel  18 . The use of a shaft adaptor  10  to attach a golf club shaft  12  to a golf club head  16  is illustrated in  FIGS. 2 and 3 . 
   The shaft adaptor  10  comprises a cylindrical hollow body  22 . The body  22  has side walls  24 , a first end  26 , a second end  28 , an outer diameter and an inner diameter. The side walls  24  have an internal surface  30  and an external surface  32 . The side walls  24  also have at least one aperture  34  to allow the communication of liquid adhesive between the external surface  32  of the side walls  24  and the internal surface  30  of the side walls  24 . 
   The at least one aperture  34  can be irregular in shape or not. In the embodiment illustrated in the drawings, the side walls  24  have a plurality of rectangular shaped apertures  34 . The apertures  34  are defined by side wall elements comprising a plurality of spatially spaced annular members  36  connected to one another by a plurality of longitudinal members  38 . Each annular member  36  has a smooth interior surface and a smooth exterior surface. In the embodiment illustrated in the drawings, the annular members  36  are of a uniform thickness and each have an identical width. This is not necessary in the invention, however, so long as the annular members  36  are sufficiently smooth so as to not do damage to the hosel  18  of a golf club head  16  or to a golf club shaft  12  during the use of a golf club  14  employing the shaft adaptor  10 . In the invention, the average width of each annular member  34  is typically at least about 5 times greater than the maximum thickness of the annular members  34 . 
   The golf club adaptor  10  can further comprise a cylindrical hollow ferrule  40  disposed at the first end  26  of the shaft adaptor  10 . The ferrule  40  has side walls  42 , an inner diameter which is substantially the same as the inner diameter of the hollow body  22  and an outer diameter which is greater than the outer diameter of the hollow body  22 . The ferrule  40  is typically used to cover the outer annulus of the hosel  18  after the shaft adaptor  10  and the golf club shaft  12  have been inserted into the hosel  18 . 
   The entirety of the shaft adaptor  10  can be made as a single unit from a plastic material. One such plastic is ABS with low styrene, high flow characteristics and high impact characteristics so that the part can be handled without breaking. Other materials can also be used so long as the materials are sufficiently soft so as not to cut into the golf club head  16  or the golf club shaft  12  during use of a golf club  14  employing the shaft adaptor  10 . 
   In a typical embodiment, the shaft adaptor  10  is used to attach the distal end  20  of a golf club shaft  12  having an outer diameter of about 0.335 inches into a hosel  18  having a diameter of about 0.35 inches. Thus, a typical shaft adaptor  10  has an overall length of 1.105 inches, an external diameter of 0.354 inches and an internal diameter of 0.338 inches. The shaft adaptor  10  has a ferrule  40  with a maximum outside diameter of about 0.540 inches. The shaft adaptor  10  is comprised of a plurality of annular members  36  having a width of between about 0.075 inches and about 0.100 inches and a plurality of longitudinal members  38  having a width of about 0.05 inches. The plurality of annular members  36  and the plurality of longitudinal members  38  define a plurality of rectangular shaped apertures  34  having a width of about 0.121 inches and a length of about 0.207 inches. 
   In another typical embodiment of the invention, the adaptor  10  is 1.308 inches in length, 0.400 inches in outer diameter and 0.335 inches in internal diameter. In yet another typical embodiment of the invention, the adaptor  10  is 0.330 inches in length, 0.436 inches in outer diameter and 0.335 inches in internal diameter. 
   The invention has been found to provide an inexpensive but effective adaptor for the attachment of a golf club shaft to a golf club head wherein the distal end of the golf club shaft has a diameter narrower than the diameter of the hosel. The shaft adaptor of the invention avoids prior art problems regarding the ineffective attachment of the golf club shaft, adaptor and golf club head into a cohesive whole because the apertures within the side walls of the shaft adaptor allow for the efficient flow of liquid adhesive throughout the internal surfaces and external surfaces of the side walls of the shaft adaptor. Because of the smooth construction of the shaft adaptor and/or the use of soft materials, such as plastics, the shaft adaptor does not tend to damage either the golf club shaft or the golf club head during use of the golf club, even when the golf club shaft is made from graphite fibers. 
   Having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described hereinbelow by the claims.