Abstract:
A weighting device for removably attaching to a golf club. The device has a mass with a bore formed therethrough and an access slot in open communication with the bore. The slot provides an entrance opening in the mass that is transverse to the bore for attaching the device to a shaft of a golf club.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to golf training devices, and, more particularly, to a weight that is removably attachable to any location on a golf club shaft. 
   Removable golf club weight training devices are known in the art. A number of these devices are attachable to a shaft of a golf club using various types of mechanisms. Many of these devices are of the type which attach to the golf club shaft only at the lower end of the shaft, i.e., adjacent the head of the golf club. Those devices which can be attached to different areas on the golf club shaft are commonly complicated and require some type of tightening mechanism to fixedly attach the weight to the shaft so that it does not move when the golf club is swung. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawings in which: 
       FIG. 1  illustrates the weight training device of the present invention positioned on a golf club shaft; 
       FIG. 2  is a perspective view of the weight training device of the present invention; 
       FIG. 3  is a cross-sectional view taken along the lines  3 — 3  of  FIG. 2 ; 
       FIG. 4  is a cross-sectional view of the weight training device taken along the lines  4 — 4  of  FIG. 2 ; and 
       FIG. 5  is an elevation view showing the initial insertion of the club shaft into the access slot. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Turning now to  FIG. 1 , there is shown one embodiment of the inventive weight training device  10  positioned on a shaft  12  of the golf club  14 . The golf club  14  is conventional having a handle  16  and a golf club head  18 . The device  10  is typically football shaped, i.e., having a largest diameter in the center and then tapering to a smaller diameter at opposite ends. One of the features of the present invention is the ability to position the weight training device  10  at any location on the shaft  12  of the golf club. As illustrated in  FIG. 1 , the weight can be positioned midway on the shaft such as is indicated by the device  10 A in phantom lines or the device could be positioned near the grip  16  of the club as shown by the phantom line representation at  10 B. In order to understand how the device is constructed so as to be positionable at any of these selected locations on the shaft so that the device will not move when the shaft is swung, reference is now made to  FIG. 2  which is a perspective view of the device  10 . As will become apparent, the device  10  is generally football shaped as opposed to being oval, i.e., the device is uniform with respect to a center point so that either end may be placed in an up or down position. However, the particular shape of the device is not critical and the body may take the shape of a sphere, cube or rectangle. The device  10  has a longitudinal bore  20  extending from end to end of the device. The bore is preferably circular in cross-section and includes a plurality of circumscribing ribs  22  forming a sequence of discontinuous threads throughout the length of the bore. These circumferential or annular ribs  20  provide a plurality of surfaces which engage the surface of the golf club shaft  12  and inhibit sliding motion of the device  10  on the shaft  12 . The bore  20  is sized to fit snugly on the shaft  12  regardless of the position of the device  10  on the shaft. Since the shaft  12  generally tapers from the grip  16  to the club head  18 , the bore  20  is sized to fit snugly at the smallest diameter end of the shaft  12  adjacent the club head  18 . At the upper end of the shaft  12  adjacent the grip  16 , the device  10  fits more tightly about the club shaft whereby sliding motion of the device  10  is further inhibited. 
   Considering  FIGS. 2–5  concurrently, it can be seen that the device  10  has a slot-shaped opening or access slot  24  that extends into the device  10  and intersects the central bore  20 . The slot  24  is transverse to the direction of the bore  20  and allows the device  10  to be attached to the club shaft  12  by pushing the device on to the shaft through the slot  24  and then rotating the device of about 90 degrees so that the shaft is directed into the central bore  20 . The initial position of the shaft  12  in the slot  24  is shown in  FIG. 5  prior to rotation of device  10  into the position shown in  FIG. 1 . 
     FIG. 3  is a cross-sectional view taken along the lines  3 — 3  of  FIG. 2  and  FIG. 4  is a cross-sectional view transverse to  FIG. 3  through the central bore  20 .  FIG. 5  is an elevation view showing the initial insertion of the club shaft  12  into the access slot  24 . The annular rings  22  in bore  20  are shown in  FIG. 4 . 
   The weight training device  10  is similar in shape and in the manner of installation to the device shown in U.S. Pat. No. 3,680,870. However, the device of the &#39;870 patent is designed solely to be positioned on a golf club shaft adjacent the head of the club and has a large diameter bore at one end to enable the device to slide onto the hosel of the club head. The club head then acts as a retainer to prevent the device from disengaging from the club as the club is swung. The location of the weight device for training is limited to this one position and therefore only trains or loosens the large back muscles of the user. 
   In contrast, the present invention is constructed to fit at any location on a club shaft and to remain in that location while the club is swung. For example, the device  10  can be positioned as shown at  10 B in  FIG. 1  so that swinging of the club tends to cause a more pronounced wrist action to train the user in producing club head acceleration in the golf ball impact zone. By moving the weight device  10  to the position indicated at  10 A, swinging the club effects strengthening of the forearms to produce a more forceful swing. 
   The weight device  10  uses a bore  20  diameter that fits snugly about shaft  12  at its smallest diameter, i.e., adjacent head  18 , and therefore fits more tightly about shaft  12  at other locations. The annular ribs  22  provide a restraining function on shaft  12  while allowing the bore  20  to be sized to fit on shaft  12  without distorting the device  10  nor requiring excessive force to fit the device on shaft  12  where the shaft has its larger diameters. The device  10  is preferably a high-density polymer product such as polyurethane, having rubber-like characteristics. The weight of device  10  can be adjusted by molding metal weights, typically lead, into the device. However, applicant has found that younger golfers may use lighter weight devices of about 4 ounces and not require metal inserts. Different weights can be used for golfers of different strengths or skill levels but a weight of about 8 ounces has been found to be comfortable for most golfers. In such a typical embodiment, the device  10  is about 4 inches in length and about 2 inches in diameter at its widest point.