FIELD OF THE INVENTION 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 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.
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'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'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.
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.
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 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 DRAWINGSFIG. 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.
FIG. 2 is a cross-sectional view of the putter grip shown inFIG. 1.
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.
FIGS. 4athrough4fshow the putter grip of the present invention in use during the putting stroke.
DETAILED DESCRIPTION OF THE INVENTION Configuration
FIGS. 1 and 2 shows the upper portion of agolf club shaft8, upon which is included agrip assembly10 of the present invention. Thegrip assembly10 includes anupper hand grip20 and alower hand grip30. Theupper hand grip20 is secured to theshaft8 to prevent both rotational movement around theshaft8 and translational movement along the length of theshaft8. In contrast, thelower hand grip30 is attached to theshaft8 in such a manner as to allow both rotational movement (represented by arrows40) and axial or translational movement (represented by arrows42) with respect to theshaft8.
In the embodiment shown inFIGS. 1 and 2, this is accomplished in part via the use of acylindrical core element50. Thishand grip core50 is placed over the upper portion ofshaft8 and fixed thereto through conventional means known in the prior art, such as glue, epoxy, or double-sided adhesive tape. Theupper grip20 is located on theupper portion52 ofcore50 and is fixed thereto, such as by attaching theupper grip20 to thecore50 or by forming theupper grip20 out of a portion of thecore50. In one embodiment of the present invention, thecore50 is formed with a plurality ofopenings54 along itsupper portion52. These openings allow the epoxy or tape that is used to secure thecore50 to theshaft8 to also contact theupper hand grip20 and secure thatgrip20 in place. Regardless of the technique used, movement of theupper grip20 with respect to theshaft8 is prohibited.
In the preferred embodiment, thelower hand grip30 is implemented as a grippingsurface32 surrounding a sleeve orhub34. Thishub34 is preferably implemented as a second cylinder having an internal diameter slightly larger than the outer diameter of thehand grip core50. When thishub34 is then placed over thelower portion56 of thehand grip core50, the comparative sizing allows thehub34 and the rest of thelower hand grip30 to move both axially along thecore50 and rotationally around thecore50. The relative diameters of thehub34 and thecore50 should be such as to allow both rotation and axial movement of thehub34 along thecore50 while also maintaining a generally coaxial alignment of thehub34 andcore50. To lower the friction between the interior ofhub34 and the exterior ofcore50, it is possible to use a variety of techniques known in the prior art, such as conventional lubrication, ball bearings integrated into thehub34 orcore50, 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 ofhub34 and the exterior ofcore50 to reduce friction.
The axial movement of thelower hand grip30 is restricted by an upper slide stop60 and alower slide stop62. Thesestops60,62 are attached tocore50 at such positions so as to allow thelower hand grip30 to slide axially (arrows42) with respect to thecore50 and hence with respect to thegolf club shaft8. Thestops60,62 are preferably made using a resilient ring that can be stretched to move along thecore50 to their preferred location. In an alternative embodiment, the upper slide stop60 either abuts theupper grip20 or is formed integral to theupper grip20. The invention would also function appropriately if thestops60,62 were not movable, but were rather fixed to certain locations on thecore50 orshaft8.
The distance between thestops60,62 must exceed thelength36 of thelower hand grip30 enough so as to allow significant axial movement. Preferably, thelower hand grip30 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.
In some putter configurations, such as with long and extra long shaft putters, it would be possible to separate theupper grip portion20 from thelower grip portion30 along thegolf club shaft8, such as shown inFIG. 3. These putters would still benefit from the uniquelower grip portion30 of the present invention that allows bothrotational movement40 andaxial movement42 of thegrip30 around theshaft8.
As shown inFIG. 4ato4f,thelower hand grip30 is free to rotate and move axially relative to the core50 during the putting stroke.FIG. 4ashows a golfer100 addressing aball110 at the beginning of the putting stroke. The golfer100 is using aputter120 having alower grip portion130 that allows movement rotationally and axially with respect to the rest of the putter during the putting stroke. InFIG. 4b,the golfer100 begins his backstroke. The lower grip portion allows the golfer's lower hand to extend smoothly down the putter shaft on the back swing. This is shown inFIG. 4c.InFIG. 4d,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 inFIGS. 4eand4f.The slide travel for a given putt is determined geometrically by the golfer's arm length and arm separation or shoulder width. Throughout the putting stroke shown inFIGS. 4a-4f,thelower grip portion130 is free to rotate about the shaft of theputter120.
The movement of the golfer's lower hand along and around the shaft ofputter120 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.
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 thelower grip130 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.
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 thelower grip130 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 thelower grip130 in the form of a small shake or vibration.
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 cylindricalinner core50 around which theupper grip20 is attached and thelower grip30 is allowed to move axially and rotationally. It would be well within the scope of the present invention to separate the core50 from theupper hand grip30, so that theupper hand grip30 is attached directly to theshaft8. In addition, it would be within the scope of the present invention to utilize a specially constructedshaft8 that provided an essentially cylindrical portion to take the place ofcore50. The upper and lower slide stops60,62 would then be mounted directly on theshaft8. Consequently, the invention should be limited only by the following claims.