Patent Publication Number: US-10315083-B1

Title: Golf club grip

Description:
FIELD OF THE INVENTION 
     The invention relates to golf clubs, more particularly to golf club grips. 
     BACKGROUND 
     Golf is a popular sport played with a club that generally has a head, a shaft, and a grip. Some golfers like accessories such as various sensors and other technologies that enhance their performance and/or enjoyment of the game. Thus, some golf clubs are provided with accessories which are housed within the grip of the club. 
     When an accessory is incorporated within a grip of a club, the manner in which the accessory is incorporated can make a difference in the feel to the golfer and/or the performance of the golfer. For example, the impact of the club with the ball could result in movement of the accessory within the grip, which can affect the golfer&#39;s performance and/or feel of the golf club. Additionally, depending on the type of accessory that is provided to the grip, such as a sensor for tracking an aspect of performance, the movement of the accessory within the grip could negatively affect the ability of the accessory to properly acquire/analyze data. 
     One recurring problem is that placing an accessory within a grip sometimes causes an undesirable deformation of the grip, such as a bulge around the grip, that distracts the golfer and causes the golfer to think that the grip feels awkward and uncomfortable. 
     SUMMARY 
     The present invention provides for a golf club grip having a housing portion specifically for housing an accessory, wherein the grip is specifically configured to enhance performance and enjoyment of the game of golf. Grips of the invention help to provide a smoother gripping surface and to prevent relative motion between the accessory and the club when the accessory is coupled to the club. 
     Preferred embodiments provide a grip for a golf club in which an internal bore for receiving a golf club shaft is flared, or increases in diameter, as the internal bore approaches a butt end of the grip. When such a grip is placed on a golf club with an accessory inserted into a recess within the grip, the flared area of removed material—relative to a prior art grip—avoids the awkward bulge that otherwise results from inclusion of the accessory. 
     In order to reduce the bulging and deformation that may occur in the butt end of the grip when an accessory is housed within a grip, the circumference of at least a portion of the internal bore is designed to decrease in a direction from the first end to the second end. In this way the circumference of the internal bore is larger toward the butt end of the grip, which helps to provide a consistent taper on the outer dimension of the grip, reduce grip to shaft interference, and remove bulging that may occur. 
     In certain embodiments, only a portion of the internal bore has a decreasing circumference. In other embodiments, the internal bore gradually tapers all the way from the first end to the second end. 
     In addition to the decreasing circumference of the internal bore, as noted above, the outer dimension is usually tapered. In certain embodiments, the outer dimension gradually tapers from the housing portion down to the shaft opening. Depending on the taper of the outer dimension and the circumference of the internal bore, the distance between the outer dimension and the inner dimension at any two cross sections taken along a plane perpendicular to a longitudinal axis of the grip can vary. For example, in one embodiment, the distance between the outer dimension and the inner dimension at any two cross sections taken along a plane perpendicular to a longitudinal axis of the grip at any point where the circumference of the internal bore decreases is substantially equal. In yet another embodiment, the distance between the outer dimension and the inner dimension taken at a first cross section along a first plane perpendicular to a longitudinal axis of the grip at the first end is smaller than the distance between the outer dimension and the inner dimension taken at a second cross section along a second plane perpendicular to the longitudinal axis at a point along the decreasing circumference of the internal bore that is distal to the first end. 
     The housing portion can be formed as a continuation of the sleeve member or can be a separate piece that is coupled to the sleeve member. In a preferred embodiment, the housing portion is formed as a continuation of the sleeve member. In certain aspects the housing portion defines a recess with an open end at the proximal end of the grip for receiving the accessory. A flange separating the housing portion from the internal bore can also be provided. In some embodiments a hole extends through the flange, the hole capable of receiving a portion of the accessory therethrough. For example, the accessory can comprise a main body and a stem, with at least a portion of the stem extending through the hole. 
     In addition to, or as an alternative to, providing a tapered internal bore with a decreasing circumference, in certain embodiments, the grip includes a region or panel of harder material positioned along the inner dimension toward the first end. This additional material will have a durometer that is higher than a durometer the rest of the grip. In certain embodiments, the grip also includes an end cap at the proximal end of the grip, wherein the end cap has a durometer substantially equal to the durometer of the additional material. 
     The panel length can be described with respect to the length of the internal bore as measured from the first end to the second end. In one embodiment, the panel has a length that is less than 50% of the length of the internal bore. In certain embodiments, the panel has a length that is less than 30% of the length of the internal bore. 
     Generally, the additional material has a first side facing the outer dimension and a second side facing the internal bore. In certain embodiments, the second side is flush with the inner dimension of the sleeve member. In these embodiments, the thickness of the panel can be described with respect to the distance between the inner dimension and the outer dimension. For example, in certain aspects, the panel has a thickness greater than 10% of a distance between the inner dimension and the outer dimension. In other aspects, the panel has a thickness greater than 25% of the distance between the inner dimension and the outer dimension. 
     Furthermore, in addition or alternative to providing an internal bore with a decreasing circumference and/or adding a panel of higher durometer material to the sleeve member, in certain embodiments, the accessory to be housed within the recess of the housing portion is configured to include a main body having circular cross sections, a top end positioned at the proximal end of the grip, a bottom end, and side walls that taper from the top end to the bottom end. The accessory will have a largest radius toward the top end that is greater than an internal radius of the recess, such that an interference fit between the accessory and an internal surface of the recess is created. The interference fit will help to reduce movement of the accessory within the grip and can also help to create a consistent taper on the outer dimension, both of which help to improve the feel of the club and performance by reducing discomfort and distraction, as well as reducing movement within the club during impact. 
     In certain embodiments, the largest radius of the accessory is about 2% greater than the internal radius of the recess. In other embodiments, the largest radius of the accessory is about 5% greater than the internal radius of the recess. In still other embodiments, the largest radius of the accessory is about 10% greater than the internal radius of the recess. 
     In certain aspects, the accessory also includes a stem extending from the bottom end of the main body. In certain embodiments, at least a portion of the stem extends through the hole in the flange when the accessory is housed within the recess of the housing portion. The stem can include one or more protrusions extending outward perpendicularly from a longitudinal axis of the grip. The protrusions are to be spaced apart from the main body of the accessory by at least a distance equal to or greater than the thickness of the flange. In this way, when the accessory, such as an electronic device with, e.g., one or more of a sensor, battery, chip, etc., is inserted into the recess with the stem extending through the hole, the main body of the accessory is on one side of the flange and the protrusions are on the other side such that the protrusions help to prevent the accessory from falling out of the hole. 
     In yet another embodiment, the grip includes a retaining member housed within the housing portion and in seated communication with the accessory such that the retaining member is positioned between the accessory and the open end. The retaining member will have a protrusion that extends into an indentation, or slot, within the internal surface of the recess, thus locking the retaining member in place within the housing while also securing the accessory within the grip. In certain aspects, the retaining member comprises a material, such as rubber, that deforms when subjected to pressure. In some embodiments, the retaining member comprises an annular shape. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a grip with conic internal bore. 
         FIG. 2  is a close-up, cross-sectional view through a portion of the grip. 
         FIG. 3  is a cross-sectional view along the grip. 
         FIG. 4  is a cross-sectional across a butt-end of the grip. 
         FIG. 5  is a cross-sectional across the grip. 
         FIG. 6  is a cross-sectional view along a constant taper grip. 
         FIG. 7  shows a cross section view across a butt portion of the constant taper grip. 
         FIG. 8  shows a cross section view across a mid-portion of the constant taper grip. 
         FIG. 9  shows a grip with a region of harder material 
         FIG. 10  shows a grip with a region of harder material as a discrete panel. 
         FIG. 11  shows an accessory for use with a grip of the disclosure. 
         FIG. 12  shows the accessory positioned in the grip. 
         FIG. 13  shows an accessory with a locking stem. 
         FIG. 14  shows insertion of the locking-stem accessory into the grip. 
         FIG. 15  shows a cut-away view of a grip with a retaining member. 
         FIG. 16  shows a golf club with a grip 
         FIG. 17  diagrams a method of making a grip. 
     
    
    
     DETAILED DESCRIPTION 
     The invention generally provides a golf club grip configured to house an accessory. The grip is specifically configured to enhance performance and enjoyment of the game of golf, such as by providing a smoother gripping surface and preventing relative motion between the accessory and the club when the accessory is coupled to the club. 
       FIG. 1  shows a grip  101  for a golf club having a sleeve member  109  with a gripping surface, a shaft opening  107 , and a housing portion  105  at the butt end  115  of the grip configured to house an accessory. Flange  113  generally separates an internal bore for receiving a shaft from housing portion  105 . Flange  113  may define hole  103 , which can be configured to receive part of an accessory (not pictured in  FIG. 1 ). Flange  113  around the bottom of the housing portion of the grip can act as a stopper so that the shaft does not extend into the housing portion and does not make contact with the main body of the accessory when installed in the grip. The housing portion  105  can be formed as a continuation of the sleeve member  109  or can be a separate piece that is coupled to the sleeve member  109 . In a preferred embodiment, the housing portion  105  is formed as a continuation of the sleeve member  109 . 
     Preferably, sleeve member  109  provides a golfer with a good grip on the club. 
     The sleeve member  109  can include textured portions, which can be ridges, valleys, knobs, divots, irregular protrusions or recesses, or any other suitable method of providing a gripping surface. Material of the grip can also be made tacky, for instance by choosing a soft rubber, polymer, or composite or by impregnating a primary material with a secondary compound. The sleeve member  109  also has an outer dimension (OD) and an inner dimension (ID). 
       FIG. 2  is a close-up, cross-sectional view through a portion of the grip  101 . The ID can gradually taper from the housing portion  105  down to the distal portion  111 , as shown in  FIG. 3 . The flared, or tapered, portion of the inner bore  120  creates a conic region  137  at which the inner bore is not cylindrical. Dashed lines in  FIG. 2  do not form part of the grip  101  and instead are drawn only to show what would be a smooth, cylindrical continuation of the inner bore  131  similar to what is found on standard prior art grips. 
     It is also to be understood that the OD and/or the ID can vary in any manner throughout the sleeve member such that the distance between the OD and the ID varies depending on which perpendicular plane the measurements are taken. For example, in one embodiment, the ID of the internal bore  120  toward the butt end  115  can flare, reducing the distance between the ID and the OD, as shown in  FIG. 4 . It is also contemplated that the distance between the OD and the ID can vary at any point along the same perpendicular plane, as shown in  FIG. 5 . 
       FIG. 3  is a cross-sectional view along the grip  101 . As shown, the conical portion  137  is adjacent the butt-end of the grip  101 . By having some material “removed” (relative to a prior art grip with cylindrical bore), the grip  101  performs better when an accessory is inserted into the recess  103  provided by the housing  105 . Cross-sectional views illustrate the conical portion  137  provided by the flared shape within the inner bore  120   
       FIG. 4  is a cross-sectional across through the grip  101  along line  4  in  FIG. 3 , near a butt-end of the grip  101 . 
       FIG. 5  is a cross-sectional across through the grip  101  along line  5 . It can be seen that the inner diameter increases along the conical portion  137  approaching a butt end of the grip  101 . It has been found that placing an accessory into a prior art grip causes certain problems; prior art grips bulge outwards slightly when an accessory is pushed into a recess in the prior art grip. The invention includes molding a grip  101  with a conical flared portion  137  along a butt end of an internal bore  120 , which flared internal bore relieves and avoids the slight bulge associated with insertion of the accessory into a prior art grip. 
     In yet another embodiment (not shown), both the OD and the circumference of the internal bore can flare to the same degree toward the butt end  115 , such that the distance between the ID and the OD remains essentially the same, similar to  FIG. 6 . 
     The internal bore  130  can be formed using any manufacturing methods known in the art. For example, a core bar having a desired shape can be provided, around which the grip is formed, such that the ID of the internal bore  120  is consistent with the outer dimensions of the core bar used to form the grip. In one embodiment, the core bar has a substantially cylindrical shape, such that the ID of the internal bore  120  remains constant from the housing portion  105  to the distal portion. In another embodiment, the core bar has a tapered shape, such that the ID of the internal bore  620  gradually tapers, as shown in  FIG. 6 . In yet another embodiment, the core bar has a flared shape towards the housing portion  105 , such that the ID of the internal bore  120  also flares, as shown in  FIG. 3 . 
     While a flared internal bore near the butt-end relieves the grip  101  from bulging when the accessory is inserted, other configurations may serve such as, for example, a flared conical bore along a length of the grip. 
       FIG. 6  is a cross-sectional view along a constant-internal taper grip  601 . The grip  601  has an internal bore  620  along the sleeve member  609 . The grip  601  also includes a housing  605  providing a recess to house an accessory. The internal bore  620  is substantially conic in that it tapers continually from a butt end  608  of the grip  601  to a distal end  607 . Cross-sectional views aid in illustrating the conic taper. 
       FIG. 7  shows a cross section view across grip  601  taken at line  7 . 
       FIG. 8  shows a cross section view across grip  601  taken at line  8 . In grip  601 , the consistent taper of both the OD and the ID helps to reduce any grip to shaft interference and/or removes bulging at the butt end of the grip that could arise with a prior art grip when an accessory is used. 
     While a flared internal bore relieves the grip  101  from bulging when the accessory is inserted, other features may be included or used additionally or alternatively to also prevent the bulge. 
     Grips according to the present disclosure can have a constant or variable hardness. In grips made from rubber and/or plastic, this hardness is often measured and expressed in durometers, which is typically defined as a material&#39;s resistance to indentation. In one embodiment, the grip can have a substantially constant hardness, accounting for any manufacturing variance, etc. In another embodiment, the grip can have varying hardness. For example, in one embodiment, the durometer at the butt end  115  of the grip, such as throughout the housing portion  105  and/or on an end cap, is higher than the durometer throughout most of the sleeve portion  109 , especially towards the distal end  111 . 
       FIG. 9  shows a grip  901  that includes a sleeve member  909  with a gripping surface, a shaft opening  907 , and a housing portion  905  at the butt end  915  of the grip configured to house an accessory. Flange  913  generally separates an internal bore for receiving a shaft from housing portion  905 . The sleeve member  909  includes a first material  911 . An outer surface of the sleeve member has a gripping surface. The housing  905  defines a recess configured to house an accessory at a proximal end of the sleeve member  909 . 
     The grip  901  includes a region  933  of harder material  937  proximal to an inner surface of the sleeve member  909  and located closer to the recess  925  then to the shaft opening  907 . The harder material  937  has a durometer that is higher than a durometer of the first material  911 . 
     Flange  913  may define hole  903 , which can be configured to receive part of an accessory. Flange  913  around the bottom of the housing portion of the grip can act as a stopper so that the shaft does not extend into the housing portion and does not make contact with the main body of the accessory when installed in the grip. The housing portion  905  can be formed as a continuation of the sleeve member  909  or can be a separate piece that is coupled to the sleeve member  909 . In a preferred embodiment, the housing portion  905  is formed as a continuation of the sleeve member  909 . In certain embodiments, the region  933  of harder material  937  has a length extending less than 50% of a length of the internal bore as measured from the first end to the second end. 
     The first material  911  and the harder material  937  may be different materials (e.g., different molding compounds) that are molded together such that the two materials essentially transition seamlessly from the first material  911  to the harder material  937 , e.g., at the dotted lines shown defining the region  933 . The first material  911  and the harder material  937  can be substantially the same material albeit with slightly different chemistries or curing time and temperature parameters. For example, both the first material  911  and the harder material  937  can be a rubber, latex, or silicon but the harder material  937  may be doped or impregnated with a compound that confers a harder durometer to the harder material  937  than a durometer of the first material  911 . 
     In some embodiments, the region of harder material comprises a panel of a second material, distinct from the first material, disposed within the sleeve member. 
       FIG. 10  shows a grip  1001  that includes a sleeve member  1009  with a gripping surface and a housing portion  1005  at the butt end  1015  of the grip configured to house an accessory. Flange  1013  generally separates an internal bore for receiving a shaft from housing portion  1005 . The sleeve member  1009  includes a first material  1011 . An outer surface of the sleeve member has a gripping surface. The housing  1005  defines a recess  1025  configured to house an accessory at a proximal end of the sleeve member  1009 . 
     The grip  1001  includes a region of harder material  1037  provided as a discrete panel  1033 . The panel  1033  of harder material  1037  is preferably proximal to an inner surface of the sleeve member  1009  and located closer to the recess  1025  then to the shaft opening. The harder material  1037  has a durometer that is higher than a durometer of the first material  1011 . 
     Additional panels of higher durometer material may be added along the grip. 
     In the preferred embodiment, the panel  1033  of higher durometer material is disposed along the ID of the sleeve member  1009  toward the butt end  1015  of the grip  1001  abutting the flange  1013 . In this embodiment, the butt end  1015  also has a higher durometer than the rest of the sleeve member  1009 . By adding the panel  1033  of higher durometer material to the sleeve member  1009  toward the butt end  1015  of the grip, the stability of the club is improved when the club is gripped and swung. Additionally, the durometer of a material can also have an effect on an outer shape of the grip  1001 . 
     The dimensions of the panel  1033  can vary in both length and thickness as desired to impart optimal performance, feel, and aesthetics. In some embodiments, the panel  1033  has a length extending less than the length of the internal bore as measured from the first end to the second end. For example, the length of the panel can extend less than 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, or 10% the length of the internal bore. 
     The panel  1033  of additional material will have a first side that faces the outer dimension and a second side that faces the internal bore  120 . The second side is preferably flush with the inner dimension of the sleeve member. Accordingly, the thickness can be described with respect to the distance between the ID and the OD. For example, the panel can have a thickness of greater than 10%, 20%, 25% 30%, 40% 50%, 60%, 70%, 75%, 80% or more of the distance between the inner dimension and the outer dimension. 
     The durometer of the sleeve member  109  distal to the housing portion, not including the panel  1033 , will typically be in the range of about 35 to about 60 on the Shore “A” scale. The durometer of the butt end  115 , such as the end cap, will fall within a higher range, such as between about 60 and about 100 on the Shore “A” scale. The additional panel  1033  will have a durometer that is higher than the sleeve portion. In some embodiments, the durometer of the additional material is substantially equal to the durometer of the butt end, accounting for any manufacturing variances, etc. In other embodiments, the durometer of the additional material is between the durometer of the sleeve member and the butt end. 
     The grip can be made of any material suitable for being held by a user. For example, the grip can be made with cord manufactured from cotton. Grips made from cord can be half or full corded. Grips can also be made of a rubber or plastic material. Some grips can be made from a blend of liquid rubber and granulated cork, optionally pressure molded, sanded, or painted. Grips can be made of plastics or polymer materials such as, for example, Ethylene Propylene Diene Monomer (EPDM). Grips can be made of leather such as cowhide, calfskin or kangaroo. They can be spiral wrapped. Corded grips can be corded with strands of thread, e.g., to create a non-slip “rain grip”. A grip or a component of a grip according to the invention can be injection molded, compression molded, or a combination thereof. Examples of suitable materials or methods of making a grip are described in Golf Club Grip, U.S. Pub. 2007/0072696. 
     The invention provides grips for use with any golf club including, for example, drivers, irons, hybrids, wedges, and putters. For example, where the invention provides a putter grip with a housing, the grip can be tubular, tapered, a paddle style (with a flat area for the thumbs), a pistol style (with a protruding area), or any other style known in the art. A grip of the invention can be substantially evenly round or have a reminder (i.e., a line or rib on the grip that reminds the golfer where the hand should be placed). 
     A grip can be made to have a graphic, emblem, or marked area. A mark, graphic, or emblem can include an area of a different thickness or texture (e.g., a bas-relief), a pigment, a sticker, a medallion, or other indicator. Generally, such an indicator may be a corporate logo or other visible element, a reminder (e.g., tactile), or both. In some embodiments, a grip of the invention is designed to complement a club with a repositionable shaft. Exemplary club systems are described in Interchangeable Shaft System, U.S. Pub. 2009/0197694; Interchangeable Shaft System, U.S. Pub. 2009/0264214; Interchangeable Shaft System, U.S. Pat. No. 7,699,717; Interchangeable Shaft System, U.S. Pub. 2011/0143854; Interchangeable Shaft and Club Head Connection System, U.S. Pat. No. 7,878,921; Interchangeable Shaft and Club Head Connection System, U.S. Pub. 2010/0261543; Interchangeable Shaft and Club head Connection System, U.S. Pub. 2009/0247316; Quick Release Connection System for Golf Clubs, U.S. Pub. 2008/0125239; Two-Part Hosel Connection System for Golf Clubs, U.S. Pub. 2008/0254909; and Interchangeable Shaft for a Golf Club, U.S. Pat. No. 7,476,160, the contents of each of which are herein incorporated by reference in their entirety. 
     Clubs that include a shaft repositionable relative to a club head sometimes provide that the club head may be repositioned at different relative rotations around the shaft axis. In some embodiments, a grip according to the invention includes a graphic, an indicator, or a shape, such that an appearance of the club and grip to a spectator is substantially similar regardless of the effective head-shaft position. For example, where a head can be fixed on a shaft in three different positions, each defined by an angular offset from the others of 120 degrees, a grip of the invention can exhibit three-fold rotational symmetry, whereby a visible element of the grip is repeated to appear in three places, each offset from the others by a 120 degree angular offset. This way, regardless of an effective setting of the golf club, the club and grip appear the same, for example, on a camera recording the game of golf being played. That is, if the grip has a corporate logo on it designed to face forward from the golfer when the club is at address, the grip can have three such logos, so that one is always facing forward from the golfer when the club is at address. With or without a logo or any other graphic or other visible element, a grip according to the invention can be made a solid color, or a multi-color theme according to a pattern or an irregular mix (e.g., tie-dyed, marbled, or speckled). 
     With reference back to the housing portion of the grip, the housing portion  105  can hold a variety of objects (including, but not limited to electronics, weights, training devices, accessories). Preferably the interior housing portion of the grip is dimensioned properly to allow for expansion when shafted and still provide a tight fit around an object. 
     Pliable generally refers to a material that is easily flexible and resists fatigue. Natural rubber, synthetic rubber and compound materials can be used alone or in conjunction with a number of cord and surface configurations to offer a certain tactile, softness or gripping characteristics. Preferably, a grip includes a rubber or elastic material which can be bent down, but also which exerts force on an accessory, for example, by virtue of the tacky surface or the elastic or frictional properties of the material. 
     Whatever features, colors, materials, or contours are included, a grip may generally be described by its dimensions and other intrinsic properties. The housing portion of the grip can be described according to aspects of the recess formed therein. In some embodiments, the housing portion includes a generally cylindrical recess surrounded by a generally tubular wall. The “depth” of the recess can be described by measuring a length of the recess (or the surrounding wall) in a direction generally parallel to a shaft axis (e.g., longitudinal axis of the grip), if the grip were installed on a club. The size of the recess may also be described by reference to an internal radius (e.g., of the surrounding wall), measured in a direction perpendicular to the longitudinal axis. The housing may further be described with reference to a measurement of an external radius of the surrounding wall. A thickness of the wall may be described by a difference of the internal and the external radius. 
     In some embodiments, a length or an internal radius of the recess is between about 6 and about 26 mm. The external radius may be between about 8 mm and about 30 mm. Generally, the length of the wall (i.e., the length of the recess) may be greater than about 9 mm. In preferred embodiments, a length of the recess is between about 8 mm and about 13 mm; an internal radius is between about 10.5 mm and about 14.5 mm; an external radius is between about 11.5 mm and about 19.5 mm; or any combination thereof. In certain embodiments, the length of the recess may be about 11.5 mm, the internal radius may be about 12.5 mm, the thickness of the wall may be about 2 mm, the maximum length of the grip may be about 27 cm, or any combination thereof. 
     Generally, the grip may have a mass between about 40 grams and about 55 grams, or between about 15 grams and about 70 grams. Preferably, the grip has a mass between about 44 grams and about 53 grams. In certain embodiments, the mass is between about 48 grams and about 52 grams. 
     In some embodiments, the grip may be scaled up, or scaled down (e.g., for a club for a younger person or very tall person, or for a mini or outsized model club or grip for display as a demonstration) and proportions of the grip may then generally be described by reference to ratios that do not have units. In some embodiments, a ratio of a length of the recess to a thickness of the wall is greater than four and may be between about 5 and about 7. In some embodiments, a ratio of a length of the recess to a thickness of the wall is between about 5.5 and about 6.5. Preferably, a ratio of the length of the recess to a thickness of the wall is at least about 2.5 or about 3. In some embodiments, a ratio of a length of the recess to an internal or external radius of the recess is between about 7 and about 2.5, and may preferably be between about 8 and about 1.5. Generally, a ratio of an external radius of the recess to an overall length of the grip may be between about 0.02 and about 0.12, and may be between about 0.03 and about 0.09. Preferably, a ratio of an external radius of the recess to an overall length of the grip may be between about 0.05 and about 0.06. Generally, a ratio of a length of the recess to an overall length of the grip may be between about 0.01 and about 0.09, and may preferably be between about 0.02 and 0.07. In some embodiments, a ratio of a length of the recess to an overall length of the grip may be between about 0.035 and 0.05. 
     A grip of the invention generally may have any mass depending on its scale and size. In some embodiments, a grip of the invention has a mass between about 10 grams to about 70 grams, preferably between about 30 grams and about 60 grams. In a preferred embodiment, a grip has a mass of between about 40 grams and about 55 grams, preferably between about 51 and about 53 grams. 
     In certain aspects, the invention provides a grip and an accessory  201 . 
       FIG. 11  shows accessory  201 , in accordance with one embodiment, having a main body  203  and a stem  205  partially inserted to a club shaft near an inside-out housing  105  at the end of sleeve member  109 . One or more of cutout  207  can be provided in stem  205  allowing stem  205  to be squeezed to have a smaller circumference at least at part of its length (e.g., during insertion), thereby allowing accessory  201  to be coupled to the golf club substantially by an expansive force—the force exhibited in an outward direction generally perpendicular to the shaft axis by the “legs” of stem  205 , due to its being squeezed into the golf club shaft. It is also understood that the accessory could also have no stem. 
       FIG. 12  shows the accessory  201  is fully positioned in the grip. Due to elastic properties, dimensions, and surface properties, motion of accessory  201  relative to the club is prevented. 
     Due, at least in part, to the contact of housing  105  on accessory  201 , the grip exerts forces on accessory  201  that resist motion. When housed, accessory  201  is prevented from moving relative to a golf club in any of a number of modes including twisting, rotation, revolution, swiveling, shearing, longitudinal, or any combination thereof. This phenomenon relates to the coupling of an interior surface of housing  105  to an exterior surface of the accessory  201 . By matingly coupling—that is, substantially matching and complementing each other in dimensions—surface contact creates much of the desired force. Accordingly, a grip of the invention provides the beneficial result that relative motion between the accessory and the club is prevented during play, which includes restricting such motion to less than fractions of a millimeter in any relevant direction. In some embodiments, when a club is played, a coupled accessory moves less than about a tenth or a quarter of a millimeter relative to the club and, due to elastic properties of the grip, returns to its relative original position. 
       FIG. 13  shows an accessory  1301  for insertion into the club at the butt end  115  of the grip has tapered side walls  1304 . The accessory  1301  generally includes a main body  1303  and a stem  1305 . As shown, the side walls  1304  of the accessory taper from the top end of the main body  1303  toward the bottom end. The  1305  presents one or more protrusions  1309  extending outward. The stem is to be inserted into the hole  103 . The protrusions should extend outward from the stem  1305  in a direction perpendicular to the longitudinal axis and to a point that extends beyond the radius of the hole  103 . The protrusions  1309  are also spaced along the stem  1305 , starting at a predetermined distance d away from the point at which the stem  1305  extends downward from the main body  1303  of the accessory  1301 . The predetermined distance d should be equal to or greater than the thickness of the flange  113 . In this manner, once the accessory is inserted into the recess  130  with the stem  1305  extending through the hole  103 , the protrusions  1309  help to prevent the accessory  201  from becoming dislodged from the recess  130  by abutting the bottom surface of flange  113 . 
       FIG. 14  shows insertion of the accessory  1301  into the recess  130  of the grip, such that the largest radius of the accessory  1301  is positioned closest to the butt end  115  of the grip. 
     The taper of the side walls  1304  of the accessory  201 , in conjunction with straight walls forming the inside of the recess  130  within which the accessory  1301  is to be inserted, provides an interference fit. An interference fit is typically defined as a fit between two parts in which the external dimension of one part slightly exceeds the internal dimension of the part into which it fits. Here, the top end of the accessory  1301  with the largest radius is to have a radius that slightly exceeds the internal radius of the recess  130 . In this way, once the accessory  1301  has been inserted into the recess  130 , a secure, tight fit is provided. Additionally, because part of the accessory  1301  exceeds the internal radius of the recess  130 , the part of the accessory  201  exceeding the internal radius pushes out on the walls of the recess  130  once inserted, creating a taper or flare on the outer dimension of the grip. 
     The protrusions  1309  on an accessory  1301  can have any shape that is suitable for allowing the accessory  1301  to be inserted through the hole  103 , yet helps prevent the accessory  1301  from falling out of the recess  130  once inserted. In certain embodiments, the protrusions  1309  have a rounded shape at the outer edges to allow for easier insertion into the hole  103 , such as, for example, a ring shape, nub, or rod shape having rounded edges. The accessory can have any number of the same or different protrusions  1309 . For example, an accessory could have one, two, three, four, five, six, seven, eight, nine, ten, or more protrusions. The protrusions can have any width, breadth, or dimensions as would be recognized as suitable by one of skill in the art. The protrusions  1309  can be any material that is flexible/pliable, such as a rubber/elastomeric, plastic, composite, etc. material that allows for the deformation of the protrusions to facilitate insertion past the flange  113 . 
     In yet other embodiments (not shown), the protrusion(s)  1309  is retractable when a force is exerted on it from one direction, such that the protrusion retracts into the stem upon pressure from the flange when being inserted into the recess, but then extends outward and locks in place once inserted past the flange. 
     In some embodiments an outside wall of housing portion  105  will have a slight “reverse taper” to more tightly grip accessory  1301 , thereby preventing or inhibiting relative motion. Reverse taper generally refers to a tapering in a direction opposite of tapering of sleeve member  109 . The outside wall can taper in by an amount between about 2° and about 8°, preferably about 5°. 
       FIG. 15  shows a cut-away view of a grip  1601  with a retaining member  1605 . Here, an accessory  1602  is held in place within the recess of the grip by a retaining member  1605 . The retaining member  1605  is configured to sit on top of the accessory  1602  once the accessory  1602  is inserted into the recess  1630  within the grip and is in sitting contact with the flange  1613 . The retaining member  1605  can be made out of any material and may be malleable and/or flexible, such as for example, a rubber material. In certain circumstances, it can be difficult to insert the accessory into the recess  1630  and into a position in which the accessory will be held in place. By introducing a malleable and/or flexible retaining member to hold the accessory in place, the retaining member can be more easily deformed than the accessory when being pushed into position. 
     Additionally, in order to secure the accessory  1602  in place within the recess  1630 , the retaining member  1605  is configured such that at least a portion of its outer dimension that comes in contact with the inner dimension of the recess  1630  extends radially into a slot  1610 , such as a groove or notch, within the inner wall of the recess  1630 . The retaining member  1605  can have any general shape suitable to remain engaged with the inner wall of the recess  1630  and hold the accessory in place, such as a cylindrical, disk, donut, or annular shape. In certain embodiments, the shape and dimensions of the retaining member  1605  can be such that the entire thickness of the member  1605  fits into the retaining slot  1610  (not shown). In other embodiments, the thickness of the retaining member  1605  is greater than the height of the slot  1610 . In this case, the retaining member will have at least one protrusion  1607  that radially extends into the retaining slot  1610 . 
     The retaining member  1605  may be a flexible ring having an annular protrusion  1607  that can be deformed when inserted into the recess and then engage with the retaining slot  1610  within the recess wall to hold the mechanism and accessory in place. Additionally, accessory  1602  can be configured to have a raised middle portion that abuts the inside surface of the retaining member  1605 , which can further help lock the accessory in place with the retaining member  1605 . It is also understood that the accessory  1602  does not have to have a raised middle portion and can have any shape, such as a flat shape, for its top surface. 
       FIG. 16  shows a golf club  1901  that includes a club head  1925  with a shaft  1903  connected to the head  1925  via a hosel  1915  that extends upwards from the club head  1925  when the golf club  1901  is at address. A grip  101 ,  601 ,  901 ,  1001 ,  1601  is mounted on a proximal end of the shaft  1903 , by insertion of the shaft  1903  into an inner bore of the grip  101 ,  601 ,  901 ,  1001 ,  1601 . An accessory  201  is disposed within a recess with the grip  101 ,  601 ,  901 ,  1001 ,  1601 . Embodiments of the invention provide the golf club  1901  or a kit comprising a grip  101 ,  601 ,  901 ,  1001 ,  1601  and the accessory  201 . In certain embodiments, the invention provides a housing portion (either part of the grip or as a separate piece) that stabilizes an accessory relative to a club during play or a kit including such a housing portion and such an accessory. One exemplary accessory that can be stabilized by the grip with a housing portion of the present invention includes an orientation and time-sensing alarm as described in Orientation/Time Sensing Alarm Device For Golf Club, U.S. Pat. No. 6,753,778, incorporated by reference herein in its entirety. In some embodiments, provision of a housing portion allows the grip to house an electronic device that was previously only known to be containable within a shaft of the club (see, e.g., Golf Club Rhythmic Swing Meter, U.S. Pat. No. 6,517,352, incorporated by reference herein in its entirety) entirely or substantially (e.g., &gt;than 60% of its volume) inside of the grip, and also substantially outside of the shaft of the club—providing for greater ease of interchangeability. 
     The accessory  201  can confer any number of desirable functions to golf clubs. In certain embodiments, accessory  201  includes one or more of a motion sensor, accelerometer, gyroscope, and light detector. A device can be included that detects or measures motion of the club in any one of, or any combination of, numerous modes including acceleration, translation motions, vibration, shock, tilt, and rotation. 
     The accessory  201  can offer a desired function such as swing improvement or training, situational on-off switching, or gesture recognition (e.g., two quick vertical shakes of a golf club signals an app on a golfer&#39;s smart phone to mark a position on a map for future reference). In some embodiments, the accessory  201  includes one or more of an accelerometer with low-g sensing ranges (e.g., roughly human generated), an accelerometer with high-g sensing ranges (e.g., roughly vehicle generated), a gyroscope, a multi-axis gyroscope unit, a multi-axis accelerometer unit, or a combination thereof. 
       FIG. 17  diagrams a method  1701  of making a grip  101 . The method  1701  includes obtaining  1705  a mold for a grip. Before making the grip, a core bar is provided 1713. Importantly to a preferred embodiment, the core bar is flared  1725  towards an end corresponding to a butt-end of the grip  101 . The flared portion of the core bar will provide that the grip  101  has an internal bore that is at least partially conic, rather than entirely cylindrical. Rubber is introduced  1729  into the mold. After molding and any curing, the formed grip  101  is released  1735  from the mold. 
     INCORPORATION BY REFERENCE 
     References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made throughout this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes. 
     EQUIVALENTS 
     Various modifications of the invention and many further embodiments thereof, in addition to those shown and described herein, will become apparent to those skilled in the art from the full contents of this document, including references to the scientific and patent literature cited herein. The subject matter herein contains important information, exemplification and guidance that can be adapted to the practice of this invention in its various embodiments and equivalents thereof.