Abstract:
A golf training aid utilizes a sliding ball assembly enabling sensory feedback for training golfers to make correct golf swings.

Description:
PRIORITY CLAIM 
     This utility patent application is a continuation of U.S. patent application Ser. No. 11/866,138 filed Oct. 2, 2007 now U.S. Pat. No. 7,682,267 which is a continuation of U.S. patent application Ser. No. 11/394,328 filed Mar. 28, 2006, now U.S. Pat. No. 7,297,078, which claims priority from Prov. Pat. Appl. No. 60/667,712 filed Apr. 1, 2005. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the mechanical arts. In particular, the invention relates to a training aid used by golf players to learn and/or improve golf playing techniques including swinging a golf club. 
     2. Discussion of the Related Art 
     Golfers have long trained with the implements of their sport to learn the game. The wooden clubs of the early 1900&#39;s have been improved by stronger and lighter parts made of metals and more recently composites. But, improvements in golf clubs have not led to similar improvements in aids and methods for training new golfers. Rather, developing effective aids and methods for training golfers has not been focused on by the industry. 
     SUMMARY OF THE INVENTION 
     The present invention discloses a training aid for players of the game of golf. In particular, the training aid is useful for teaching golfers proper swing mechanics. Taking a form similar to a golf club, the training aid has a relatively long shaft and is used, among other things, to train golfers how to make a proper golf swing. 
     The training aid employs a ball assembly that slides along a portion of the shaft during a swing. In various embodiments the travel of the ball assembly is limited to motion along the shaft and between first and second collars fixed to the shaft. The first collar is located near the club&#39;s hand grip and the second collar is located near the club&#39;s head. 
     The training aid provides visible and audible swing quality signals to the player. The use of a regulation or replica golf ball provides the player with a visual indication of correct swing timing. In addition, a distinct snap-like sound occurs when the ball assembly impacts the free-end collar. The sound triggers the memory at impact and allows the user to see the correct timing of the swing. This combined proprioceptive input enhances the player&#39;s awareness of hand-eye coordination and timing while conditioning and training the specific muscles used for swinging. 
     It is a further advantage of the training aid that a damper is incorporated in the ball assembly to reduce the mechanical shock when the ball assembly collides with the free-end collar. Coulomb damping resulting from friction between the ball and a damper tube inserted in the ball dissipates the energy of the collision resolving the shock and shock related swing distortion and wear problems associated with the repetitive collisions of contacting parts. 
     In an embodiment, a training aid for golfers comprises an elongated shaft having a free end and a handle end near an end opposing the free end. A damper tube is slidably engaged with the shaft and a replica golf ball is dampingly engaged with the damper tube. The ball and the damper tube are operative to move relative to each other when the free end of the shaft is swung toward the ground near a golfer&#39;s feet and the damper tube collides with a collar fixed to the shaft. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention are described herein with reference to the accompanying figures. The figures form part of the specification and together with it are intended to provide illustrative examples of the invention sufficient to enable a person of ordinary skill in the relevant art to make and use the invention. 
         FIG. 1A  shows a perspective view of a golf training aid in accordance with the present invention. 
         FIG. 1B  shows parts of a ball assembly of the golf training aid of  FIG. 1A . 
         FIG. 2A  shows a first cross-sectional view of an assembled ball assembly of the golf training aid of  FIG. 1A . 
         FIG. 2B  shows a second cross-sectional view of an assembled ball assembly of the golf training aid of  FIG. 1A . 
         FIG. 3A  shows a first perspective view of a shaft and club head portion of the golf training aid of  FIG. 1A . 
         FIG. 3B  shows a second perspective view of a shaft and club head portion of the golf training aid of  FIG. 1A . 
         FIG. 4  shows a perspective view of a shaft of the golf training aid of  FIG. 1 . 
         FIGS. 5A-C  show a stop collar of the golf training aid of  FIG. 1 . 
         FIG. 6  shows a club head and stub shaft of the golf training aid of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1A  shows a training club  100 A in accordance with an embodiment of the present invention. The training club includes a shaft  102 , a first collar  104 , a second collar  106 , and a replica golf ball assembly  108 . 
     The shaft  102  of the training club  100 A has a handle end  110  opposite a free-end  112 . A handle section of the shaft  114  adjacent to the handle end provides space for the golfer to hold the club with two hands. While the golfer may hold the bare shaft, some embodiments provide a grip  116  attached to the handle section for, inter alia, improving the golfer&#39;s control of the club. As used herein, attachments, fixtures and the like include direct and indirect connections. In an embodiment, the shaft is a metallic tube such as a ferrous or nonferrous tube. In some embodiments, the shaft is made from composite materials such as a carbon composite construction. And, in some embodiments the weight of the training club and its weight distribution are similar to that of a regulation or standard golf club. 
       FIG. 1B  shows separated parts of the ball assembly  100 B. The ball assembly  108  includes a replica golf ball  202  and a damper tube  204  having flanges at opposed ends. In an embodiment, a first flange  216  is part of the damper tube and a second flange  214  is for attachment to an opposed end  215  of the damper tube (as shown). In various embodiments, the flanges may be a part of or separate from the damper tube and means of attachment include permanent and removable attachments such as adhesives, mating threads, set screws, roll pins and other suitable attachments known to persons of ordinary skill in the art. 
     The ball assembly  108  is slidably engaged with the shaft  102 . The first collar  104  is located between the handle section  114  and the free-end  112  of the club  100 . The second collar  106  is located between the first collar and the free-end. Together, the two collars limit the sliding motion of the ball assembly to a region of the shaft located between the two collars. 
     In an embodiment, the location of the collars  104 ,  106  may be adjusted, for example by use of a fastener such as a set screw  105 . As used herein, fastener means any suitable fastener known to persons of ordinary skill in the art such as screws, clamps, bolts, roll pins and spring operated catches. Adjustment of the collars provides a means to select the length and region of the shaft  102  traversable by the ball assembly  108 . In some embodiments the weights of the collars are varied to adjust club weight, club balance and/or club response. For example, in some embodiments the weight of the second collar is increased for strength training. 
       FIGS. 2A and 2B  show assembled golf ball assemblies  108   a,    108   b.  The ball assembly includes a replica golf ball  202 , for example a regulation golf ball or another suitable replica of a golf ball, and a damper tube  204  that is inserted in a through hole  206  in the ball. 
     In an embodiment, the hole  206  has a substantially constant cross-sectional area defining a geometric centerline that is about coextensive with an axis x-x passing through the center of the ball. In some embodiments, the replica golf ball is a regulation golf ball with a through hole. And, in some embodiments, the golf ball is made from one or more materials including a suitable jacket material such as a polymer, for example plastic, and a suitable core material such as a resilient polymer, for example rubber, plastic or the like. 
     The damper tube  204  has an inner surface  210  and means at opposed ends to limit the travel of the ball  202  that slides on the tube. In various embodiments, the damper tube has a first flanged end  216 , and a second flanged end  214 . 
     Referring also to  FIGS. 3A and 3B , the second flanged end  214  is for striking the second collar  106 . In some embodiments, the flange and collar materials and/or structures are chosen to audibly emphasize the collar/flange contact. In an embodiment, one or both of the flange and collar are resonant metal structures such as structures with thin peripheral rims or diaphragms. 
     In an embodiment, the first flanged end  216  is for striking the first collar  104  (as shown) and in another embodiment, the first flanged end  216  is for striking the second collar  106 . In some embodiments, the flange and collar materials and/or structures are chosen to audibly emphasize the collar/flange contact. In some embodiments one or both ends of the damper tube are butt ends and in some embodiments one or both ends of the damper tube are flanged ends. In an embodiment, the damper tube is preferably made from a polymeric material such as polyethylene. 
     The outer surface of the damper tube  218  is in sliding contact and/or dampingly engaged with the side walls of the through hole  212  since the fit between the outer surface of the damper tube and the side walls of the through hole is an interference fit (gap shown in  FIGS. 2A and 2B  is for clarity). The amount of interference, material, and material surface properties determine the force required to overcome the related frictional forces tending to prevent the ball  202  from sliding along the damper tube  204 . In an embodiment, the damper tube and the through-hole  206  have generally circular cross-sections. 
     In another embodiment, a suitable resilient material such as textiles including felts and piled materials or an elastomer such as a foam material is interposed between the outer surface of the damper tube  218  and the side walls of the through hole  206 . Preferably, the resilient material is attached to the side walls of the through hole such that the damper tube  204  slides with respect to an adjacent surface of the resilient material which rubs against it. In an embodiment the resilient material is an elastomer such as an open-cell foam. 
     In an embodiment, an electronic signaling device  122  is mounted within the shaft  102 , stub shaft  602  and/or within the second collar  106 . The signaling device emits an audible sound in response to the second flanged end of the damper tube  214  reaching the second collar  106 . In an embodiment, an electronic sensing and signaling device provides swing diagnostics information including swing dynamics based on data acquired from sensors during the swing. Exemplary sensors used for this purpose include one or more of accelerometers for sensing relative motion and radio wave type locators including global positioning systems (GPS) and similar systems for obtaining position based on trilateration. Diagnostics are reported to the player and/or other persons using one or more of lighted indications and audible sounds emanating from the training aid and remote printers or video displays. In some embodiments the swing diagnostics are reported by a speech generator  1003  in signal communication  1005  with the electronic signaling device. 
     Various embodiments of the invention are used to train and/or improve a golfer&#39;s swing. The golfer handles the training club in a manner that is similar to the way a regulation or standard club would be handled. When a swing is made the ball assembly  108  moves from its rest against the first collar  104 , along the shaft  102 , and impacts the second collar  106  with an audible snap-like sound. 
     When the ball assembly  108  is at rest against the first collar  104 , the first flanged end of the damper tube  216  is about flush with an outer surface of the replica golf ball  222  and the second flanged end of the damper tube  214  has its maximum projection  220  from the outer surface of the replica golf ball as shown in  FIGS. 2A and 3A . When the ball assembly  108  nears the free-end of the training club  112 , the second flanged end of the damper tube  214  strikes the second collar  106 . The mechanical shock of this collision and the resulting wear of the colliding parts is reduced by Coulomb or frictional damping when the ball drags along the outer surface of the damper tube  218  and absorbs a portion of the energy/shock of the collision. Where electronic signaling devices  122  are mounted in the training club  100 A, the Coulomb damping of the ball assembly tends to preserve the life of these electrical and/or electronic devices by reducing the mechanical shocks experienced during training. 
     When the ball assembly  108  comes to rest against the second collar  106  the first flanged end of the damper tube  216  has its maximum projection  219  from the outer surface of the ball  222  and the second flanged end of the damper tube  214  is about flush with the outer surface of the ball as shown in  FIGS. 2B and 3B . 
     In another embodiment, preparation for another swing requires only that the golfer raise the training club  100 A during the backswing to restore the damper tube&#39;s maximum projection  220 . Here, the backswing causes the ball assembly  108  to slide back toward the club&#39;s handle end  114  causing the first flanged end of the damper tube  216  to strike the first collar  104 . This collision causes the ball  202  to slide relative to the damper tube  204  until the first flanged end of the damper tube  216  is about flush with the outer surface  222  of the ball  202 . 
     The ball  202  and the damper tube  204  are operative to move relative to each other when the free end of the club  112  is swung toward the ground near a golfer&#39;s feet and the damper tube collides with a collar fixed to the shaft  106 . 
     Here, the ball and the damper tube are operative to dissipate kinetic energy of the ball when relative motion between the ball and the damper tube causes coulomb damping to occur. 
     In various embodiments, the training club provides a golfer with one or more signals from which to judge the quality of his swing. First, the “feel” of the swing informs the golfer about the swing. Since the training club uses a replica golf ball  202  rather than a weight, neither the swing dynamics nor the related player sensations are distorted when the ball slides along the length of the shaft  102  during the swing. Second, the replica golf ball is easily observed by the golfer as the free-end of the training club  112  passes in front of the golfer. A correct swing is one in which the golfer observes the ball reaching the second collar of the club  106  just as the club head  199  reaches the ball. Third, the sound of the damper tube flange  214  striking the second collar  106  provides a timed, audible indication of when the club should be striking the ball. 
     In some embodiments, the club head  199  can be removed. For example,  FIG. 4  shows a golf training aid shaft portion  400  having upper and lower ends  408 ,  406 . Here, the shaft  102  has generally opposed holes  402 ,  404  to receive set screws  105  mated with the second stop collar  106 .  FIGS. 5A-C  show the generally opposed and threaded set screw holes  502 ,  504  of the second stop collar. When the stop collar is located over the holes in the shaft and the shaft holes are aligned with the stop collar holes, set screws penetrating the shaft holes provide a stop collar locking mechanism. 
       FIG. 6  shows an exemplary removable club head assembly  600  that can be used with the second stop collar  106  and shaft  102 . Here, the lower end of the shaft  406  has a bore dimensioned to receive a stub shaft of the club head assembly and the tightening of the set screws  105  passing through the opposed holes of the shaft  404 ,  406  locks the club head assembly to the shaft. A removable club head enables club head substitution with varying club heads including heavier or lighter heads and heads matching those used on a particular golf club such as a 9-iron. 
     In some embodiments, the stop collars  104 ,  106  and in particular, the second stop collar  106  provide a means of selectively weighting the golf training aid  100 A. For example, removal of the second stop collar set screws  105  from the shaft  102  enables removal and replacement of the stop collar where a removable club head  199  is used. If the head is not removable, the grip  116  and upper stop collar  105  can, for example using a design similar to that of the second stop collar, be removed to achieve the same result. Among other things, removable stop collars enable substitution of lighter or heavier collars as may be desired by the user. 
     While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.