Abstract:
A system and method is presented for a putter grip having a lower section that is free to both rotate and axially slide along the putter shaft. In the preferred embodiment, this lower grip section slides and rotates over a core upon which is mounted an upper grip section that does not move relative to the putter shaft. The lower grip section is restrained in its axial movement to a portion of the putter shaft through the use of movement stops.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to the field of golf clubs. More specifically, the present invention relates to a putter grip that allows both rotational and axial movement of the grip along the shaft of the putter.  
       BACKGROUND OF THE INVENTION  
       [0002]     The ideal putter grip is one that most effectively assists the golfer in achieving the two basic elements of putting: establishing the initial course or direction of the ball, and establishing the initial speed of the ball. These two factors alone determine the path that the golf ball will travel. Of course, there are a number of variables that a golfer must analyze in order to correctly select the direction and speed for the putt, including the breaks and contours of the putting green, the grain or standing grass direction of the green, and the speed or rolling resistance of the surface.  
         [0003]     Even if a golfer has successfully evaluated the appropriate direction and speed for a putt, a golfer still needs a great deal of skill to translate this evaluation into the proper putting stroke. Golfers spend many hours practicing their putting stroke to be able to control the ball&#39;s direction and speed consistently. Most golf instructors believe that three elements are crucial when a golfer is working on their putting stroke: the hand grip, the body position, and the putting stroke. Most teaching authorities believe the golfer should hold the putter in the palms of the hands with a light grip pressure. The general consensus for body position has the feet spread apart, but within the shoulder width, the knees slightly bent, and the back straight but tilted so as to position the eyes over the ball. The golfer ideally has shoulders and toes square to the intended putt line, with arms relaxed and hanging naturally with a slight bend at elbows. The ball should be in at the midpoint between the feet. As for the putting stroke, the golfer&#39;s arms and hands should move as one unit with the putter in a pendulum motion to release the putter head along the intended target line.  
         [0004]     The goal of achieving a proper grip, stance, and stroke is not unique to putting, as the proper performance of all other golf strokes requires mastery of these same three elements. Unfortunately, while it is relatively straightforward to teach a golfer the proper grip of a club and the proper body position, it requires a great deal of effort and practice to obtain a proper stroke. For much of the last century, inventors have worked on improving the golf club to make it easier for golfers to achieve a better golfing stroke. One common approach has been to improve golf clubs by using a rotating grip, as is seen in Suesman (U.S. Pat. No. 1,305,952); De Bus (U.S. Pat. No. 1,544,226); Moore (U.S. Pat. No. 2,225,839); Hrivnak (U.S. Pat. No. 3,804,413); Smolinski (U.S. Pat. No. 3,834,714); Martin (U.S. Pat. No. 5,413,339); and Madelle (U.S. Published Patent No. US2001/0041626. All of these references describe golf clubs having a grip that moves rotationally with respect to the golf club shaft during the hitting stroke.  
         [0005]     Unfortunately, a simple rotational club handle does not successfully meet the specific needs for an improved grip on a golf club used for putting. The need still exists for a grip on a putter that more properly assists a golfer in obtaining a preferred putting stroke.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention overcomes the limitations in the prior art by providing a putter grip with an upper grip section that is fixed to the putter shaft, and a lower grip section that is free to both rotate and axially slide along the putter shaft. In one embodiment, this lower grip section actually slides and rotates over a core that is also used by the upper grip section. Slide stops on this core then restrain the axial motion of the lower section to a limited portion of the putter shaft.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a plan view of an improved putter grip of the present invention, with arrows showing the range of motion available to the lower grip section.  
         [0008]      FIG. 2  is a cross-sectional view of the putter grip shown in  FIG. 1 .  
         [0009]      FIG. 3  is a plan view of a second embodiment of the present invention putter grip, with the upper grip section separated from the lower grip section, such as when used on an elongated putter shaft.  
         [0010]      FIGS. 4   a  through  4   f  show the putter grip of the present invention in use during the putting stroke. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0000]     Configuration  
         [0011]      FIGS. 1 and 2  shows the upper portion of a golf club shaft  8 , upon which is included a grip assembly  10  of the present invention. The grip assembly  10  includes an upper hand grip  20  and a lower hand grip  30 . The upper hand grip  20  is secured to the shaft  8  to prevent both rotational movement around the shaft  8  and translational movement along the length of the shaft  8 . In contrast, the lower hand grip  30  is attached to the shaft  8  in such a manner as to allow both rotational movement (represented by arrows  40 ) and axial or translational movement (represented by arrows  42 ) with respect to the shaft  8 .  
         [0012]     In the embodiment shown in  FIGS. 1 and 2 , this is accomplished in part via the use of a cylindrical core element  50 . This hand grip core  50  is placed over the upper portion of shaft  8  and fixed thereto through conventional means known in the prior art, such as glue, epoxy, or double-sided adhesive tape. The upper grip  20  is located on the upper portion  52  of core  50  and is fixed thereto, such as by attaching the upper grip  20  to the core  50  or by forming the upper grip  20  out of a portion of the core  50 . In one embodiment of the present invention, the core  50  is formed with a plurality of openings  54  along its upper portion  52 . These openings allow the epoxy or tape that is used to secure the core  50  to the shaft  8  to also contact the upper hand grip  20  and secure that grip  20  in place. Regardless of the technique used, movement of the upper grip  20  with respect to the shaft  8  is prohibited.  
         [0013]     In the preferred embodiment, the lower hand grip  30  is implemented as a gripping surface  32  surrounding a sleeve or hub  34 . This hub  34  is preferably implemented as a second cylinder having an internal diameter slightly larger than the outer diameter of the hand grip core  50 . When this hub  34  is then placed over the lower portion  56  of the hand grip core  50 , the comparative sizing allows the hub  34  and the rest of the lower hand grip  30  to move both axially along the core  50  and rotationally around the core  50 . The relative diameters of the hub  34  and the core  50  should be such as to allow both rotation and axial movement of the hub  34  along the core  50  while also maintaining a generally coaxial alignment of the hub  34  and core  50 . To lower the friction between the interior of hub  34  and the exterior of core  50 , it is possible to use a variety of techniques known in the prior art, such as conventional lubrication, ball bearings integrated into the hub  34  or core  50 , or linings/coatings using low friction surfaces such as graphite or TEFLON.® It is also within the scope of this invention to use no special lubrication means, and simply rely on the relative smooth surfaces on the interior of hub  34  and the exterior of core  50  to reduce friction.  
         [0014]     The axial movement of the lower hand grip  30  is restricted by an upper slide stop  60  and a lower slide stop  62 . These stops  60 ,  62  are attached to core  50  at such positions so as to allow the lower hand grip  30  to slide axially (arrows  42 ) with respect to the core  50  and hence with respect to the golf club shaft  8 . The stops  60 ,  62  are preferably made using a resilient ring that can be stretched to move along the core  50  to their preferred location. In an alternative embodiment, the upper slide stop  60  either abuts the upper grip  20  or is formed integral to the upper grip  20 . The invention would also function appropriately if the stops  60 ,  62  were not movable, but were rather fixed to certain locations on the core  50  or shaft  8 .  
         [0015]     The distance between the stops  60 ,  62  must exceed the length  36  of the lower hand grip  30  enough so as to allow significant axial movement. Preferably, the lower hand grip  30  is allowed between five to ten inches of axial movement, although significant beneficial impact on the putting stroke of the average user can be obtained with greater or lesser movement ranges, including an axial movement of only a single inch.  
         [0016]     In some putter configurations, such as with long and extra long shaft putters, it would be possible to separate the upper grip portion  20  from the lower grip portion  30  along the golf club shaft  8 , such as shown in  FIG. 3 . These putters would still benefit from the unique lower grip portion  30  of the present invention that allows both rotational movement  40  and axial movement  42  of the grip  30  around the shaft  8 .  
         [0017]     As shown in  FIG. 4   a  to  4   f,  the lower hand grip  30  is free to rotate and move axially relative to the core  50  during the putting stroke.  FIG. 4   a  shows a golfer  100  addressing a ball  110  at the beginning of the putting stroke. The golfer  100  is using a putter  120  having a lower grip portion  130  that allows movement rotationally and axially with respect to the rest of the putter during the putting stroke. In  FIG. 4   b,  the golfer  100  begins his backstroke. The lower grip portion allows the golfer&#39;s lower hand to extend smoothly down the putter shaft on the back swing. This is shown in  FIG. 4   c.  In  FIG. 4   d,  the golfer has begun his forward swing and is now impacting the ball. During the forward swing, the lower grip portion beings to travel smoothly up the club shaft to the point of ball strike and beyond. The follow through of the putting stroke is shown in  FIGS. 4   e  and  4   f.  The slide travel for a given putt is determined geometrically by the golfer&#39;s arm length and arm separation or shoulder width. Throughout the putting stroke shown in  FIGS. 4   a - 4   f,  the lower grip portion  130  is free to rotate about the shaft of the putter  120 .  
         [0018]     The movement of the golfer&#39;s lower hand along and around the shaft of putter  120  during the putting stroke allows the putter head to track the target with minimum body motion or shoulder roll. This also reduces the tendency for the lower hand to misdirect the club face from the intended target line. In this way, the present invention promotes a smooth pendulum swing path and proper tempo resulting in better ball roll for all putts, short or long. The lower hand becomes very passive in terms of directing the ball heading and therefore cannot misdirect the club face orientation from the desired ball heading as set by the swing path of the upper hand.  
         [0019]     The present invention also provides a “feel and touch” feedback through the hands that continuously reinforces the proper putter swing characteristics. The free motion of the lower grip  130  provides a smoother and more natural pendulum motion in the putting stroke. This lower grip slide motion also creates the sensation that the stroke has enhanced power simply because it is so efficient. The expectation is that with less swing motion for a given putt one should have a greater success rate or accuracy.  
         [0020]     This aspect of the present invention also promotes proper tempo and shoulder roll and release. The rear shoulder (right shoulder for a right-handed player) needs to release the putter down the line through impact and beyond ball strike. Failure to release the shoulder usually results in putts not reaching the hole. Particularly with short putts, golfers tend to baby the putt or steer the ball to the hole. The free motion of the lower grip  130  also provides feedback when a ball strike is not accomplished with proper tempo or above ball center. When this occurs, a disturbance is felt through the lower grip  130  in the form of a small shake or vibration.  
         [0021]     The invention is not to be taken as limited to all of the details thereof as modifications and variations thereof may be made without departing from the spirit or scope of the invention. For instance, the above description describes a cylindrical inner core  50  around which the upper grip  20  is attached and the lower grip  30  is allowed to move axially and rotationally. It would be well within the scope of the present invention to separate the core  50  from the upper hand grip  30 , so that the upper hand grip  30  is attached directly to the shaft  8 . In addition, it would be within the scope of the present invention to utilize a specially constructed shaft  8  that provided an essentially cylindrical portion to take the place of core  50 . The upper and lower slide stops  60 , 62  would then be mounted directly on the shaft  8 . Consequently, the invention should be limited only by the following claims.