Patent Publication Number: US-2021187371-A1

Title: Golf club with adjustable weighting system

Description:
RELATED APPLICATIONS 
     This claims benefit of U.S. patent application Ser. No. 16/723,307, filed Dec. 20, 2019, which claims the benefit of Provisional Application No. U.S. 62/784,190 filed Dec. 21, 2018, and Provisional Application No. U.S. 62/855,751 filed May 31, 2019, all of which are incorporated herein in their entirety. 
    
    
     TECHNICAL FIELD 
     This disclosure relates generally to a golf club head with an adjustable weight wherein the weight system provides peripheral weighting and trajectory manipulation of the golf ball flight upon impact. 
     BACKGROUND 
     In general, there are many important physical parameters (i.e., volume, mass, etc.) that effect the overall performance of the golf club head. One of the most important physical parameters is the center of gravity (CG) of the golf club head. The CG of the golf club head directly affects the performance characteristics (i.e., moment of inertia, launch, ball speed, etc.). A desirable CG position on a golf club head is low and rearward from the strike face, to optimally raise the launch angle and MOI of the golf ball. Additionally, the CG position can be moved nearer to the toe end or heel end of the golf club head to further affect the side spin of the golf ball. 
     Many current wood type golf club heads achieve a desired CG position through the use of slidable swing weights on the sole of the golf club head, or through the use of multiple swing weight ports, wherein one or more weights can be affixed within. However, slidable swing weights and multiple weight configurations require a large amount of internal structure to support the plurality of weights and/or the different positioning of the weight(s). Further, these bulky weight systems can negatively affect the CG positioning since discretionary mass of the club head is allotted to support the weight systems. There is a need in the art for a weighting system that can variably affect the CG of the golf club head, without the need for a slidable system or plurality of weight ports. 
     Moving the center of gravity of a golf club head toward the heel or toe of the golf club head contributes to shaping golf ball flight towards a fade or draw bias. Such shot shaping is desirable to help improve a golfer&#39;s shot. However, if an adjustable weight system requires a comparatively large movement of the adjustable weight across the volume of the golf club head, then the CG of the golf club head is moved forward toward the striking face of the golf club head, and usually moved higher above the sole in the volume of the golf club head. This movement of the CG towards the striking face and higher in the club head volume reduces the combined moment of inertia of the golf club head. The reduction of club head MOI is not desirable, as the forgiveness for off center hits is reduced. Thus, in conventional adjustable weight systems, the user must choose between shot shaping and forgiveness. Further, in conventional adjustable weight systems, the larger or more distributed weight port structures are permanently placed masses that often offset the effect of the movement of an adjustable weight member to other positions on a golf club head 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       This disclosure relates generally to sport equipment and relates more particularly to golf club heads and related methods. 
         FIG. 1  illustrates a front view of a golf club head. 
         FIG. 2  illustrates a side cross-section a golf club head. 
         FIG. 3  illustrates a rear sole view of a golf club head. 
         FIG. 4  illustrates a side cross-section of the weight assembly slot structure. 
         FIG. 5  illustrates a side cross-section of the weight assembly slot structure with variable weight assembly. 
         FIG. 6  illustrates a horizontal cross-section of the variable weight assembly. 
         FIG. 7  illustrates a weight member outer surface view. 
         FIG. 8  illustrates a weight member lower surface view. 
         FIG. 9  illustrates a weight member horizontal cross-section. 
         FIG. 10  illustrates a weight member vertical cross-section. 
         FIG. 11  illustrates a cut away view of a golf club rear portion interior surface. 
         FIG. 12  illustrates a side view of a weight assembly. 
         FIG. 13  illustrates a bottom view of a weight assembly. 
         FIG. 14  illustrates a horizontal cross-section of a weight assembly. 
         FIG. 15  illustrates a bottom view of a golf club head. 
         FIG. 16  illustrates a rear, bottom view of a golf club head. 
         FIG. 17  illustrates a bottom view of a golf club head indicating a slot structure extent. 
     
    
    
     Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings. 
     DESCRIPTION 
     Described herein is a golf club head having an adjustable weight assembly. The golf club head comprises a heavy, large mass weight member mechanically fixed within a slot on the sole of the golf club head. The slot is located at the farthest rear point of the golf club head and is confined to a comparably small arc at the rear portion of the golf club head. The positioning of the adjustable weight assembly, the large mass of the weight member, and the small arc of movement of the weight member combine to address an ongoing problem associated with adjustable weight systems for golf club heads. 
     In conventional adjustable weight systems, a large movement of the adjustable weight is needed to affect ball flight, because the mass of the weight moved is relatively small. However, the large movement of the weight mass also cause relatively large decreases in the total moment of inertia of the golf club head. Thus, in a conventional adjustable weight system the user is forced to accept a decrease in forgiveness for miss-hits in order to achieve shot shaping. 
     The weight assembly slot described herein comprises two to six threaded receivers positioned relatively close to one another. The weight member can be positioned in two to six positions within the slot, to influence a straight ball flight, a right to left ball flight, and a left to right ball flight. The combination of a single, smaller slot on the sole with a single, heavy weight member leads to improvements in CG movement and MOI preservation. This is achieved by confining the slot to a relatively small arc on the rear of the golf club head. The smaller arc provided a smaller displacement towards the heel or toe of the golf club head, but the heavier weight counter balances the smaller displacement of the weight member, allowing the user to shape golf ball flight by using a comparatively smaller weight member displacement. 
     In addition, the discretionary mass that is saved from only having a single, smaller weight slot can be allocated to favorable locations to further improve the CG and MOI of the golf club head. The weight member configuration allows improvements in heel and toe movement of the CG without grossly affecting the overall CG and total inertia of the golf club head. Furthermore, the weight member and slot combination improves the heel and toe movement of the CG, without physically reallocating the mass of the golf club head to completely different portions of the golf club head. Thus, the weight member configuration allows the user to change the shot shape of the golf club head, without effecting the overall inertia and launch of the golf club head. 
     The terms “first,” “second,” “third,” “fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that comprises a list of elements is not necessarily limited to those elements but may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus. 
     The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the apparatus, methods, and/or articles of manufacture described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. 
     Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. 
     I) Golf Club Head—Introduction 
     The golf club head  100 ,  300  comprises a hosel  130 , a strike face  108 , a crown  110 , a sole  116 , a heel region  120 , a toe region  124 , and a rear portion  128 . Together, the strike face  108 , the crown  110 , the sole  116 , the heel region  120 , the toe region  124 , and the rear portion  128  form a hollow interior of the club head  100 . The golf club head  100  further comprises a slot  240  in the rear portion  128  and the sole  116 . A weight assembly  380  can be positioned and affixed within the slot  240 . 
     Referring to  FIG. 1 , the strikeface  108  of the club head  100  defines a geometric center  140 ,  340 . In some embodiments, the geometric center  140 ,  340  can be located at the geometric centerpoint of a strikeface perimeter  142 , and at a midpoint of face height  144 . In the same or other examples, the geometric center  140 ,  340  also can be centered with respect to engineered impact zone  148 , which can be defined by a region of grooves  150  on the strikeface. As another approach, the geometric center  140 ,  340  of the strikeface  108  can be located in accordance with the definition of a golf governing body such as the United States Golf Association (USGA). For example, the geometric center  140 ,  340  of the strikeface  108  can be determined in accordance with Section 6.1 of the USGA&#39;s Procedure for Measuring the Flexibility of a Golf Clubhead (USGA-TPX3004, Rev. 1.0.0, May 1, 2008) (available at http://www.usga.org/equipment/testing/protocols/Procedure-For-Measuring-The-Flexibility-Of-A-Golf-Club-Head/) (the “Flexibility Procedure”). 
     A) Golf Club Head Coordinate System 
     Referring to  FIG. 1 , the club head  100  further defines a loft plane  1010  tangent to the geometric center  140 ,  340  of the strikeface  108 . The face height  144  can be measured parallel to loft plane  1010  between a top end of the strikeface perimeter  142  near the crown  110  and a bottom end of the strikeface perimeter  142  near the sole  116 . In these embodiments, the strikeface perimeter  142  can be located along the outer edge of the strikeface  108  where the curvature deviates from the bulge and/or roll of the strikeface  108 . 
     Referring to  FIGS. 1 and 2 , the geometric center  140 ,  340  of the strikeface  108  further defines a coordinate system having an origin located at the geometric center  140 ,  340  of the strikeface  108 , the coordinate system having an X axis  1050 , a Y axis  1060 , and a Z axis  1070 . The X axis  1050  extends through the geometric center  140 ,  340  of the strikeface  108  in a direction from the heel  120  to the toe  124  of the club head  100 . The Y axis  1060  extends through the geometric center  140 ,  340  of the strikeface  108  in a direction from the crown  110  to the sole  116  of the club head  100  and perpendicular to the X axis  1050 , and the Z axis  1070  extends through the geometric center  140  of the strikeface  108  in a direction from the front end  112 ,  312  to the back end  114  of the club head  100  and perpendicular to the X axis  1050  and the Y axis  1060 . 
     Referring to  FIGS. 1 and 2 , the coordinate system defines an XY plane extending through the X axis  1050  and the Y axis  1060 , an XZ plane extending through the X axis  1050  and the Z axis  1070 , and a YZ plane extending through the Y axis  1060  and the Z axis  1070 , wherein the XY plane, the XZ plane, and the YZ plane are all perpendicular to one another and intersect at the origin of the coordinate system located at the geometric center  140 ,  340  of the strikeface  108 . The XY plane extends parallel to the hosel axis  132  and is positioned at an angle corresponding to the loft angle of the club head  100  from the loft plane  1010 . Further the X axis  1050  is positioned at a 60 degree angle to the hosel axis  132  when viewed from a direction perpendicular to the XY plane. 
     In these or other embodiments, the club head  100  can be viewed from a front view ( FIG. 1 ) when the strikeface  108  is viewed from a direction perpendicular to the XY plane. Further, in these or other embodiments, the club head  100  can be viewed from a side view or side cross-sectional view ( FIG. 2 ) when the heel  120  is viewed from a direction perpendicular to the YZ plane. 
     The club head  100 ,  300  defines a depth  160 ,  360 , a length  162 ,  362 , and a height  164 ,  364 . Referring to  FIG. 3 , the depth  160 ,  360  of the club head can be measured as the furthest extent of the club head  100 ,  300  from the front end  112 ,  312 , to the back end  114 , in a direction parallel to the Z axis  1070 . 
     The length  162  of the club head  100  can be measured as the furthest extent of the club head  100  from the heel  120  to the toe  124 , in a direction parallel to the X axis  1050 , when viewed from the front view ( FIG. 1 ). In many embodiments, the length  162  of the club head  100  can be measured according to a golf governing body such as the United States Golf Association (USGA). For example, the length  162  of the club head  100  can be determined in accordance with the USGA&#39;s Procedure for Measuring the Club Head Size of Wood Clubs (USGA-TPX3003, Rev. 1.0.0, Nov. 21, 2003) (available at https://www.usga.org/content/dam/usga/pdf/Equipment/TPX3003-procedure-for-measuring-the-club-head-size-of-wood-clubs.pdf) (the “Procedure for Measuring the Club Head Size of Wood Clubs”). 
     The height  164  of the club head  100  can be measured as the furthest extent of the club head  100  from the crown  110  to the sole  116 , in a direction parallel to the Y axis  1060 , when viewed from the front view ( FIG. 1 ). In many embodiments, the height  164  of the club head  100  can be measured according to a golf governing body such as the United States Golf Association (USGA). For example, the height  164  of the club head  100  can be determined in accordance with the USGA&#39;s Procedure for Measuring the Club Head Size of Wood Clubs (USGA-TPX3003, Rev. 1.0.0, Nov. 21, 2003) (available at https://www.usga.org/content/dam/usga/pdf/Equipment/TPX3003-procedure-for-measuring-the-club-head-size-of-wood-clubs.pdf) (the “Procedure for Measuring the Club Head Size of Wood Clubs”). 
     Referring to  FIGS. 1 and 2 , the club head  100  further comprises a head center of gravity (CG)  180  and a head depth plane  1040  extending through the geometric center  140 ,  340  of the strikeface  108 , perpendicular to the loft plane  1010 , in a direction from the heel  120  to the toe  124  of the club head  100 . In many embodiments, the head CG  180  is located at a head CG depth  182  from the XY plane, measured in a direction perpendicular to the XY plane. In some embodiments, the head CG  180  can be located at a head CG depth  182  from the loft plane  1010 , measured in a direction perpendicular to the loft plane. The head CG  180  is further located at a head CG height  184  from the head depth plane  1040 , measured in a direction perpendicular to the head depth plane  1040 . Further, the head CG height  184  is measured as the offset distance from the head depth plane  1040  in a direction perpendicular to the head depth plane  1040  toward the crown  110  or toward the sole  116 . In many embodiments, the head CG height  184  is positive when the head CG is located above the head depth plane  1040  (i.e. between the head depth plane  1040  and the crown  110 ), and the head CG height  184  is negative with the head CG is located below the head depth plane  1040  (i.e. between the head depth plane  1040  and the sole  116 ). In some embodiments, the absolute value of the head CG height  184  can describe a head CG  180  positioned above or below the head depth plane  1040  (i.e. between the head depth plane  1040  and the crown  110  or between the head depth plane  1040  and the sole  116 ). In many embodiments, the head CG  180  is strategically positioned toward the sole  116  and back end  114  of the club head  100  based on various club head parameters, such as volume and loft angle, as described below. Further, in many embodiments, the head CG  180  is strategically positioned toward the sole  116  and back end  114  of the club head  100  in combination with reduced aerodynamic drag. 
     The club head  100  can further comprises a moment of inertia I xx  (i.e. crown-to-sole moment of inertia) about an axis parallel to the X axis through the club head CG  180 , a moment of inertia I yy  (i.e. heel-to-toe moment of inertia) about an axis parallel to the Y axis through the club head CG  180 , and a moment of inertia I zz  about an axis parallel to the Z axis through the club head CG  180 . The sum of I xx , I yy , and I zz  is the total or combined moment of inertia of the golf club head  100 . In many embodiments, the crown-to-sole moment of inertia I xx  and the heel-to-toe moment of inertia I yy  are increased or maximized based on various club head parameters, such as volume and loft angle, as described in further detail below. Further, in many embodiments, the crown-to-sole moment of inertia I xx  and the heel-to-toe moment of inertia I yy , are increased or maximized in combination with reduced aerodynamic drag. 
     Described herein are various embodiments of a golf club head  100  having a movable weight assembly  380 . In many embodiments, the golf club head  100  can be wood type golf club head (i.e. driver, fairway wood, hybrid). 
     B) Driver 
     In some embodiments, the golf club head  100  can comprise a driver. In these embodiments, the loft angle of the club head can be less than approximately 16 degrees, less than approximately 15 degrees, less than approximately 14 degrees, less than approximately 13 degrees, less than approximately 12 degrees, less than approximately 11 degrees, or less than approximately 10 degrees. Further, in these embodiments, the volume of the club head can be greater than approximately 400 cc, greater than approximately 425 cc, greater than approximately 450 cc, greater than approximately 475 cc, greater than approximately 500 cc, greater than approximately 525 cc, greater than approximately 550 cc, greater than approximately 575 cc, greater than approximately 600 cc, greater than approximately 625 cc, greater than approximately 650 cc, greater than approximately 675 cc, or greater than approximately 700 cc. In some embodiments, the volume of the club head can be approximately 400 cc-600 cc, 425 cc-500 cc, approximately 500 cc-600 cc, approximately 500 cc-650 cc, approximately 550 cc-700 cc, approximately 600 cc-650 cc, approximately 600 cc-700 cc, or approximately 600 cc-800 cc. 
     C) Fairway Wood 
     In some embodiments, the golf club head can comprise a fairway wood. In these embodiments, the loft angle of the golf club head can be less than approximately 35 degrees, less than approximately 34 degrees, less than approximately 33 degrees, less than approximately 32 degrees, less than approximately 31 degrees, or less than approximately 30 degrees. Further, in these embodiments, the loft angle of the club head can be greater than approximately 12 degrees, greater than approximately 13 degrees, greater than approximately 14 degrees, greater than approximately 15 degrees, greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, or greater than approximately 20 degrees. For example, in some embodiments, the loft angle of the club head can be between 12 degrees and 35 degrees, between 15 degrees and 35 degrees, between 20 degrees and 35 degrees, or between 12 degrees and 30 degrees. 
     In embodiments where the golf club head comprises a fairway wood, the volume of the club head is less than approximately 400 cc, less than approximately 375 cc, less than approximately 350 cc, less than approximately 325 cc, less than approximately 300 cc, less than approximately 275 cc, less than approximately 250 cc, less than approximately 225 cc, or less than approximately 200 cc. In these embodiments, the volume of the club head can be approximately 160 cc-200 cc, approximately 160 cc-250 cc, approximately 160 cc-300 cc, approximately 160 cc-350 cc, approximately 160 cc-400 cc, approximately 300 cc-400 cc, approximately 325 cc-400 cc, approximately 350 cc-400 cc, approximately 250 cc-400 cc, approximately 250 cc-350 cc, or approximately 275 cc-375 cc. 
     D) Hybrid 
     In some embodiments, the golf club head can comprise a hybrid. In these embodiments, the loft angle of the club head can be less than approximately 40 degrees, less than approximately 39 degrees, less than approximately 38 degrees, less than approximately 37 degrees, less than approximately 36 degrees, less than approximately 35 degrees, less than approximately 34 degrees, less than approximately 33 degrees, less than approximately 32 degrees, less than approximately 31 degrees, or less than approximately 30 degrees. Further, in these embodiments, the loft angle of the club head can be greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, greater than approximately 20 degrees, greater than approximately 21 degrees, greater than approximately 22 degrees, greater than approximately 23 degrees, greater than approximately 24 degrees, or greater than approximately 25 degrees. 
     In embodiments where the golf club head comprises a hybrid, the volume of the club head is less than approximately 200 cc, less than approximately 175 cc, less than approximately 160 cc, less than approximately 125 cc, less than approximately 100 cc, or less than approximately 75 cc. In some embodiments, the volume of the club head can be approximately 100 cc-160 cc, approximately 75 cc-160 cc, approximately 100 cc-125 cc, or approximately 75 cc-125 cc. 
     In some embodiments, the golf club head  100  can comprise stainless steel, titanium, aluminum, a steel alloy (e.g. 455 steel, 475 steel, 431 steel, 17-4 stainless steel, maraging steel), a titanium alloy (e.g. Ti 7-4, Ti 6-4, T-9S), an aluminum alloy, or a composite material. In some embodiments, the strike face  108  of the golf club head  100  can comprise stainless steel, titanium, aluminum, a steel alloy (e.g. 455 steel, 475 steel, 431 steel, 17-4 stainless steel, maraging steel), a titanium alloy (e.g. Ti 7-4, Ti 6-4, T-9S), an aluminum alloy, or a composite material. In other embodiments, the golf club head  100  can comprise the same material as strike face  108 . In some embodiments, the golf club head  100  can comprise a different material than strike face  108 . 
     II) Weigh Assembly of Golf Club Head 
       FIGS. 1-7  illustrate an embodiment of a golf club head  100  having a variable weight assembly  380  (also referred to as a weight assembly). 
     Referring to  FIGS. 1, 2, and 4 , the golf club head  100  as described above further comprises a single slot  240  in the rear portion of the sole  116 , wherein the single slot  240  is the receiving geometry for the weight assembly  380 . The golf club head  100  does not comprise a plurality of slots. 
     Referring to  FIGS. 4, 5, 6, 7, and 16 , the slot  240  in the sole  116  of the golf club head  100  comprises an slot interior surface  242 , wherein the slot interior surface  242  is approximately perpendicular to the sole  116 . The slot interior surface  242  comprises a slot length  257 . The slot  240  comprises a slot bottom surface  244  that is perpendicular to the slot interior surface  242  and approximately parallel to the sole  116 . The slot  240  comprises a top surface  245  that is perpendicular to the slot interior surface  242  and approximately parallel to the sole  116 . The slot  240  bottom surface  244  does not extend as far towards the rear of the golf club head  100  as the slot top surface  245 . The slot  240  further comprises two sidewalls  246 . The two slot sidewalls  246  are at toeward and heelward ends of the slot interior surface  242 . The slot interior surface  242 , bottom surface  244 , top surface  245 , and two sidewalls  246  define a channel  248  open to the rear and bottom of the golf club head  100  such that when the slot  240  receives the weight assembly  380 , at least a portion of the outer  362  and lower surfaces  369  of the weight assembly  380  are both exposed. The outer  362  and lower surfaces  369  of the weight assembly  380  are not concealed or entirely surrounded by the slot bottom surface  244 . 
     The slot  240  may comprise two to six apertures. The slot  240  may comprise 2, 3, 4, 5, or 6 apertures. In most embodiments, the apertures are equally spaced, however in some embodiments, the apertures can be unevenly spaced across the interior surface  242  of the slot  240 . In the exemplary embodiment, the slot  240  comprises three apertures spaced along the interior surface of the slot  242  such that each aperture center is spaced between 0.5 inch and 0.6 inch from the adjacent aperture(s). 
     The weight assembly  380  can be positioned and affixed within the single slot  240 . The position of the weight assembly  380  within the single slot  240  determines the effect that the mass of the weight assembly  380  will have on the position of the total CG  180  of the golf club head  100 . A movement of the weight assembly  380  toward the toe  124  or heel  120  of the golf club head  100  will move the CG  180 , and will help shape the flight of a golf ball when it is struck with the golf club head  100 . 
     The single slot  240  can further comprise at least a central aperture  252 , a heel-side aperture  254 , and a toe-side aperture  256 . Each of the apertures comprise weight assembly  380  attachment points within the single slot  240 . Each of the toe-side, central, and heel-side apertures comprise a circular cross section and an aperture center. Each of the toe-side, central, and heel-side apertures are threaded to receive a threaded fastener  390 . 
     The golf club head  100  can further comprise a shroud  220 , wherein the shroud  220  is a portion of the sole  116  of the golf club head  100  that can extend to span over the slot  240 . The shroud  220  may comprise a portion or all of the bottom surface  244 . 
     In most embodiments, the shape of the interior surface of the slot  242  is complimentary to the shape of the inner surface  364  of the weight member  370 . In the exemplary embodiment, the interior surface of the slot  242  is convex and is complementary to the concave interior surface  364  of the weight member  370 . 
     The slot length  257  of the slot interior surface  242  may vary between 1.6 inches and 2.0 inches. The slot length  257  may be 1.6 inches, 1.7 inches, 1.8 inches, 1.9 inches, or 2.0 inches. The slot length  257  of the slot interior surface  242  is no longer than 2.0 inches. 
     Further, in some embodiments, the slot  240  can comprise an asymmetric shape, wherein the cross-sectional shape of the slot  240  in a heel to toe direction is non-uniform. The shape of the slot  240  is imperative to the security of the weight assembly within the slot  240 , since the asymmetric cross-sectional shape of the slot channel  248  enables three positions to align the weight assembly  380  with one of the heel-side  254 , toe-side  256 , or central  252  apertures. Due to the asymmetric shape of the slot  240  the weight assembly  380  is unable to slide throughout the channel  248 . Rather, the weight assembly  380  must be removed and placed in one of the three distinct positions. 
     Furthermore, the slot  240  can comprise a height  247  measured from the bottom surface of the slot  244  to the sole  116 . Wherein the height  247  of the slot  240  is the height of the channel  248 . In most embodiments, the slot  240  can comprise a variable height  247 , wherein the height is inconsistent in the heel to toe direction. The non-uniform height of the slot  240  is imperative to the security of the weight assembly  380  within the slot  240 , since the variable height  247  of the channel  248  enables three positions to align the weight assembly  380  with one of the heel-side  254 , toe-side  256 , or central  252  apertures. Due to the non-uniform height  247  of the slot  240  the weight assembly  380  is unable to slide laterally throughout the channel  248 . Rather, the weight assembly  380  must be removed and placed in one of the three distinct positions. This prevents the golfer from being provided unlimited position choices that create confusion in determining shot shape of the golf ball and flight. 
     The variable height  247  of the slot  240  may vary in a range between 0.2 and 0.6 inch. The variable height  247  of the slot  240  may be 0.2 inch, 0.3 inch, 0.4 inch, 0.5 inch, or 0.6 inch. 
     In some embodiments, the golf club head  100  can comprise a shroud  220 , wherein a portion of the sole  116  of the golf club head can span over the slot  240 . The shroud  220  functions to increase the aerodynamics of the channel  248  and assist in properly inserting the weight member  370  within the slot  240 . The shroud  220  can have any desired geometry to cover a specific portion(s) of the slot or the entire slot  240 . In some embodiments, the shroud  220  can cover 5%-10% of the slot, 10%-15% of the slot, 15%-20% of the slot, 20%-25% of the slot, 25%-30% of the slot, 30%-35% of the slot, 35%-40% of the slot, 40%-45% of the slot, 45%-50% of the slot, 50%-55% of the slot, 55%-60% of the slot, 60%-65% of the slot, 65%-70% of the slot, 70%-75% of the slot, 75%-80% of the slot, 80%-85% of the slot, 85%-90% of the slot, 90%-95% of the slot, or 95%-100% of the slot. 
     A) Weight Assembly 
     Referring to  FIGS. 6, 7, and 12-14 , the variable weight assembly  380  (also referred to as the weight assembly) comprises a single weight member  370  and a single mechanical fastener  390  (or fastener). The weight member  370  is configured to be positioned within the slot  240  of the golf club head  100 . The weight member  370  comprises an outer surface  362 , an inner surface  364 , side walls  366  extending between the outer surface  362  and an interior surface  364 , an upper surface  368 , a lower surface  369 , and an aperture  375  extending through the weight member  370  from the outer surface  362  to the inner surface  364 . The aperture  375  further comprises an aperture thread  377  on an interior portion of the aperture  375 . The fastener  390  is retained within the weight member  370  when the weight assembly  370  is detached from the slot  240  by means of the aperture thread  377  within the weight member aperture  375 . The lower surface  369  of the weight member  370  further comprises an indent  371  configured to receive the slot bottom surface  244  formed by an extension of the sole  116 . Wherein the extension of the sole  116  comprises the shroud  220 . The shroud  220  provides additional stability to the weight assembly  380  when it is threadably affixed to the slot  240 . 
     In some embodiments, more than one weight member  370  may be available to be affixed to the golf club head. Two weight members  370  may have different masses. However, only one weight assembly  380  may be affixed to the golf club head at a time. Two or more weight members  370  or two or more weight assemblies  380  may not be affixed to the golf club head at a time. 
     The weight member  370  can be made of any material, such as metals, polymers (e.g. thermoplastic polyurethane, thermoplastic elastomer), composites, or any combination thereof. The weight member  370  can be a polymer injection molded with different quantities of a high-density material (e.g. metal powder) or materials of different densities, to achieve backweights of varying mass, while maintaining the same volume. Injection molded weight members with different densities allow for a wide range of weight members with an identical volume and geometric shape. 
     In many embodiments, the mass of the weight member ranges between 14 g and 48 g. In some embodiments, the mass of the weight member ranges from 14 g-16 g. 16 g-18 g, 18 gr-20 gr, 20.0 g-22.0 g, 22.0 g-24.0 g, 24.0 g-26.0 g, 26.0 g-28.0 g, 28.0 g-30.0 g, 30.0 g-32.0 g, 32.0 g-34.0 g, 34.0 g-36.0 g, or 36.0 g-38.0 g. The mass of the weight assembly can be 14 g, 15, 16, 17, 18, 19, 20 g, 21 g, 22 g, 23 g, 24 g, 25 g, 26 g, 27 g, 28 g, 29 g, 30 g, 31 g, 32 g, 33 g, 34 g, 35 g, 36 g, 37 g, 38 g, 39 g, 40 g, 41 g, 42 g, 43 g, 44 g, 45 g, 46 g, 47 g, or 48 g. In many embodiments, the mass of the weight assembly (weight member and fastener) ranges between 16 grams and 50 grams. In some embodiments, the mass of the backweight assembly ranges from 16 g-18 g, 18 g-20 g, 20 g-22 g, 22.0 g-24.0 g, 24.0 g-26.0 g, 26.0 g-28.0 g, 28.0 g-30.0 g, 30.0 g-32.0 g, 32.0 g-34.0 g, 34.0 g-36.0 g, 36.0 g-38.0 g, or 38.0 g-40.0 g, 40 g-42 g, 42 g-44 g, 44 g-46 g, 46 g-48 g, or 48 g-50 g. The mass of the weight assembly can be 16 g, 17 g, 18 g, 19 g, 20 g, 21 g, 22 g, 23 g, 24 g, 25 g, 26 g, 27 g, 28 g, 29 g, 30 g, 31 g, 32 g, 33 g, 34 g, 35 g, 36 g, 37 g, 38 g, 39 g, 40 g, 41 g, 42 g, 43 g, 44 g, 45 g, 46 g, 47 g, 48 g, 49 g, or 50 g. 
     The weight member  370  may not have a mass less than 14 grams. The weight assembly may not have a weight assembly  380  mass less than 16 grams. A lower mass for the weight member  370  or weight assembly  380  will provide insufficient mass to affect golf club head performance in a meaningful manner given the restriction of movement the slot  240  size and location imposes on movement of the weight assembly  380 . 
     Referring to  FIGS. 9-11 , in the illustrated embodiment, the weight member  370  comprises a generally rectangular shape. In other embodiments, the weight member can comprise any shape. For example, the shape of the weight member can comprise a circle, an ellipse, a triangle, a rectangle, an octagon, or any other polygon or shape comprising at least two curved surfaces. 
     The weight member  370  comprises a length  374  measured along in a toe to heel direction when the weight member  370  is affixed within the slot  240 . The weight member  370  comprises a width  376  measured in a front to rear direction when the weight member  370  is affixed within the slot  240 . The weight member  370  comprises a maximum outer surface height  363  measured in a sole to crown direction along a weight outer surface  362  when the weight member  370  is affixed within the slot  240 . The weight member  370  comprises a maximum interior surface height  365  measured in a sole to crown direction along a weight interior surface  364  when the weight member  370  is affixed within the slot  240 . The weight member  370  comprises a weight member center of gravity or CG  500 . The weight member  370  is configured such that the weight member CG  500  is within the weight member aperture  375 . 
     The weight member length  374  is measured in a toe to heel direction along the interior surface  364  of the weight member  370 , The weight member length  374  may vary in range of 0.5 inch to 2.0 inch. The weight member length  374  may be 0.5 inch, 0.6 inch, 0.7 inch, 0.8 inch, 0.9 inch, 1.0 inch, 1.1 inches, 1.2 inches, 1.3 inches, 1.4 inches, 1.5 inches, 1.6 inches, 1.7 inches, 1.8 inches, 1.9 inches, or 2.0 inches. The weight member length  374  may not be greater than 2.0 inches. 
     The weight member width  376  may vary in a range of 0.4 inch to 2.0 inches. The weight member length  376  may be 0.4 inch, 0.5 inch, 0.6 inch, 0.7 inch, 0.8 inch, 0.9 inch, 1.0 inch, 1.1 inches, 1.2 inches, 1.3 inches, 1.4 inches, 1.5 inches, 1.6 inches, 1.7 inches, 1.8 inches, 1.9 inches, or 2.0 inches. 
     The weight member maximum outer surface height  363  may vary in a range of 0.2 inch to 0.6 inch. The maximum outer surface height  363  may be 0.2 inch, 0.3 inch, 0.4 inch, 0.5 inch, or 0.6 inch. 
     The weight member maximum interior surface height  365  may vary in a range of 0.1 inch to 0.5 inch. The interior surface height  365  may be 0.1 inch, 0.2 inch, 0.3 inch, 0.4 inch, or 0.5 inch. 
     When the weight assembly  380  is affixed to the golf club head  100 , the weight member  370  slopes downward from the interior surface  364  towards the outer surface  362  such that more of the mass of the weight member  370  is distributed towards the rear portion  128  and sole  116  of the golf club head  100 . This further contributes to the movement of the total CG  180  of the golf club head  100  rearwards and downwards. 
     The outer surface height  363  is greater than the inner surface height  365 , which produces the downward sloping shape of the weight member  370 . An lower surface slant or angle  373  is defined by the difference in the outer surface height  363  and the interior surface height  365 . The lower surface angle  373  may vary in a range of 1 degree to 30 degrees. The lower surface angle  373  may be 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, 10 degrees, 11 degrees, 12 degrees, 13 degrees, 14 degrees, 15 degrees, 16 degrees, 17 degrees, 18 degrees, 19 degrees, 20 degrees, 21 degrees, 22 degrees, 23 degrees, 24 degrees, 25 degrees, 26 degrees, 27 degrees, 28 degrees, 29 degrees, 30 degrees. 
     The weight member  370  further comprises a sloping reduction of its maximum height towards each end along the length  374  of the weight member. The two sloping shoulders of the weight member&#39;s reduced height further assists in the retention of the weight member  370  within the slot  240 . As the slot height  247  varies asymmetrically, the positions within the slot  240  wherein the weight member  370  may be affixed have a larger height. The sloping shoulders of the weight member  370  allow either end of the weight member  370  to fit within the slot  240  as the variable height  247  of the slot  240  decreases around the positions wherein the weight member  370  may be affixed. The sloping shoulders therefore contribute to the retention of the weight member  370  within the slot  240 , and are configured to fit within the variable height  247  of the slot  240 . 
     B) Adjustment of Weight Assembly 
     Referring to  FIGS. 12 and 13 , when the weight assembly  380  is affixed to the golf club head  100  by threadably attaching the weight member  370  with fastener  390  to one of the heel-side, central, or toe-side threaded apertures, the weight assembly  380  comprises a fastener axis  510 . The fastener axis  510  of the weight assembly  380  is an axis through a longitudinal center of the fastener  390  when the weight assembly  380  is affixed with fastener  390  to one of the heel-side, central, or toe-side threaded apertures. When the weight assembly  380  is affixed in the heel-side aperture  254 , the fastener axis defines a heel-side fastener axis  512 . When the weight assembly  380  is affixed in the central aperture  252 , the fastener axis defines a central fastener axis  514 . When the weight assembly  380  is affixed in the toe-side aperture  256 , the fastener axis defines a toe-side fastener axis  516 . 
     Because the interior surface of the slot  242  is convex, each of the toe-side fastener axis  516  and the heel-side fastener axis  512  extend in a line toward the golf club head front end  112  such that the extended axes come to a point of intersection. The point of intersection of the two axes comprises a depth from the loft plane  1010 . The fastener axis intersection point depth  540  may vary between 2.8 inches and 3.2 inches. The fastener axis intersection point depth  540  may be 2.8 inches, 2.9 inches, 3.0 inches, 3.1 inches, or 3.2 inches. 
     The toe-side fastener axis  516  and heel-side fastener axis  512  form two rays of an angle having a vertex at the fastener axis intersection point  540 . The size of the angle between the toe-side fastener axis  516  and heel-side fastener axis  512  comprises an angular separation between the two axes. Further, because toe-side and heel-side apertures are the apertures furthest apart within the slot, the two fasteners axes are at a maximum angular separation. 
     Referring to  FIG. 15 , in the exemplary golf club head, the toe-side aperture  256  and heel-side aperture  254  are the apertures that are farthest from one another within the slot  240 . The maximum angular fastener axis separation  520  of the toe-side fastener axis  516  and the heel-side fastener axis  512  varies within a range of 40 degrees and 55 degrees. The maximum angular fastener axis separation  520  may be 40 degrees, 41 degrees, 42 degrees, 43 degrees, 44 degrees, 45 degrees, 46 degrees, 47 degrees, 48 degrees, 49 degrees, 50 degrees, 51 degrees, 52 degrees, 53 degrees, 54 degrees, or 55 degrees. In the exemplary golf club head, the maximum angular fastener axis separation  520  is approximately 45 degrees. The relatively small maximum angular fastener axis separation  520  of the toe-side fastener axis  516  and the heel-side fastener axis  512  further indicates the compactness of the slot and weight assembly variable weight system. 
     Alternately, the golf club head depth  160  is in a range of 3.0 inches to 6.0 inches. Referring to  FIG. 15 , a slot support structure depth  412  comprises the difference between the total depth  160  of the golf club head  100  and the distance from the loft plane  1010  to the forward most portion  411  of the slot support structure  410 . A line parallel to the Z-axis  1070  tangent to the most heel-ward portion of the slot structure  410  is the heel-ward boundary  416  of the slot structure  410 . A line parallel to the Z-axis  1070  tangent to the most toe-ward portion of the slot structure  410  is the toe-ward boundary  418  of the slot structure  410 . The distance between the heel-ward boundary  416  and the toe-ward boundary  418  is the slot structure length  414 . 
     The slot structure depth  412  may vary in a range from 0.9 inch to 1.2 inches. The slot structure length  414  may vary in a range from 2.2 inches to 2.8 inches. 
     The slot structure depth  412  may be 0.9 inch, 1.0 inch, 1.1 inches, or 1.2 inches. 
     The slot structure length  414  may be 2.2 inches, 2.3 inches, 2.4 inches, 2.5 inches, 2.6 inches, 2.7 inches, or 2.8 inches. 
     The slot structure depth  412  may not be greater than 1.2 inches. The slot structure length  414  may not be greater than 2.8 inches. 
     Due to the limited size of the slot structure  240 , the mass of the slot structure  240  is very small in comparison to the total mass of the golf club head  100 . The mass of the slot structure  240  may be less than 7.0% of the total mass of the golf club head  100 . 
     Referring to  FIG. 11 , the slot support structure  410  further comprises a rib or ribs  420 . The rib or ribs  420  are within the hollow, interior of the golf club head  100 , and not visible from the exterior of the golf club head  100 . The rib or ribs  420  protrude from and are integrally attached to the interior surface of the slot support structure  410  and the sole  116 . The rib or ribs  420  are not attached to or protruding from any of the slot aperture housings  450 . The rib or ribs  420  may also buttress the slot structure to prevent oscillation of the slot structure during a golf club head impact of with a golf ball, given the high mass of the weight assembly affixed within the slot  240 . It is understood that the golf club head  100  is not limited to one support rib and may comprise a plurality of ribs  420 . The illustrated embodiments depict a generally planar rib  420  that extends in a front to rear direction. The rib or ribs  420  may have a geometry defined by a plurality of end points and edges. 
     Referring to  FIGS. 13 and 14 , the weight member center of gravity or CG  500  is located on the fastener axis  510  of the weight assembly  380 . Thus, when the weight assembly  380  is affixed at the apertures that are farthest from one another within the slot  240  (the toe-side aperture  256  and heel-side aperture  254 ) the weight member center of gravity or CG  500  at each position is also separated by the maximum angular fastener axis separation  520 . 
     C) Effects of Weight Assembly Displacement 
     The weight assembly  380  is moveable to each of the slot apertures. Each of the slot apertures is separated from the adjacent aperture(s) by an aperture separation distance  610 . The aperture separation distance  610  may vary in a range from 0.5 inch to 0.6 inch. The aperture separation distance  610  may be 0.5 inch or 0.6 inch. In the exemplary embodiment, the aperture separation distance  610  is 0.6 inch. Moving the weight assembly from a central aperture position  252  to either the toe-side aperture  256  or heel-side aperture  254  moves the large mass of the weight assembly  380  such that the overall CG  180  of the golf club head  100  is displaced. 
     In one embodiment, the weight assembly  380  can be configured in the slot  240  of the golf club head  100  to set up in a neutral position to hit a straight golf shot. The fastener  390  affixes within the central aperture  252  of the slot  240 . The central positioning of the weight member  370  within the slot  240  leads to a generally straight ball flight, as the center of gravity or CG  180  of the entire golf club head  100  is extremely balanced. 
     In another embodiment, the weight assembly  380  can be configured in the slot  240  of the golf club head  100 , to set up a heel-ward position, to hit a fade type golf shot. The fastener  390  affixes within the heel-side aperture  254  of the slot  240 . The heel-ward positioning of the weight member  370  within the slot  240  leads to a generally left to right ball flight (for lefthanded golfers a right to left ball flight), as the entire golf club head CG  180  is off center towards the heel portion  120 ,  320  of the golf club head  100 . 
     In another embodiment, the weight assembly  380  can be configured in the slot  240  of the golf club head  100 , to set up a toe-ward position, to hit a draw type golf shot. The fastener  390  affixes within the toe-side aperture  256  of the slot  240 . The toe-ward positioning of the weight member  370  within the slot  240  leads to a generally right to left ball flight (for righthanded golfers a left to right ball flight), as the entire golf club head CG  180  is off center towards the toe portion  124 ,  324  of the golf club head  100 . 
     Table 1 below displays the positioning of the CG  180  of the golf club head, as the weight assembly  380  is reconfigured within the slot  240 . The golf club head CG  180  is displace in terms of movement parallel to the X-axis  1050 , the Y-axis  1060 , and the Z-axis  1070 . The CG  180  differential movement in inches parallel to the X-axis is the CGx  185 , the differential movement in inches parallel to the Y-axis is the CGy  186 , and the differential movement in inches relative to the Z-axis is the CGz  187 . The results below were compiled from a 35 gram tungsten weight, a 199 g golf club head weight, and with 0.6 inches of reconfiguration (or aperture separation distance  610 ) within the slot  240  relative to the central aperture  252  when the weight assembly  380  is moved to either the heel-side aperture  254  or the toe-side aperture  256 . 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 CG position with Weight Assembly Movement 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Weight Member Position 
                 CGx 
                 CGy 
                 CGz 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Heelward 
                 0.068 
                 0.829 
                 −2.003 
               
               
                   
                 Center 
                 −0.027 
                 0.835 
                 −2.041 
               
               
                   
                 Toeward 
                 −0.122 
                 0.841 
                 −2.041 
               
               
                   
                   
               
            
           
         
       
     
     Referring to Table 1, above, the movement of CGx is approximately 0.04 inch towards the heel or 0.09 inch towards the toe from the starting center position when the weight member  370  is placed in either the heel-side aperture  254  or the toe-side aperture  256 . However, the movements of CGy and CGz are significantly smaller (less than 0.01 inch and 0.04 inch respectively). Further, the total moment of inertia or MOI decrease of the golf club head  100  is minimized. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 MOI change with Weight Assembly Movement 
               
            
           
           
               
               
               
            
               
                   
                   
                 % Change of 
               
               
                   
                   
                 Combined Club 
               
               
                   
                 Weight Member Position 
                 Head MOI 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 Heelward 
                 −3.4% 
               
               
                   
                 Center 
               
               
                   
                 Toeward 
                 1.7% 
               
               
                   
                   
               
            
           
         
       
     
     Referring to Table 2, above, the change of total MOI for the same golf club head  100  is a very small 3.4% decrease when the weight assembly  380  is shifted to the heel-side aperture  254 , and the total golf club head MOI actually increases by 1.7% when the weight assembly is shifted to the toe-side aperture  256 . Thus, as the CG  180  of the golf club head  100  is moved in a heelward or toeward direction, the forgiveness of the golf club head  100  is largely preserved. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 MOI change with Weight Assembly Movement -Prior Art 
               
            
           
           
               
               
               
            
               
                   
                   
                 % Change of 
               
               
                   
                   
                 Combined Club 
               
               
                   
                 Weight Member Position 
                 Head MOI 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 Heelward 
                 −11.0% 
               
               
                   
                 Center 
               
               
                   
                 Toeward 
                 −3.4% 
               
               
                   
                   
               
            
           
         
       
     
     Referring to Table 3, above, a comparison of a similar, prior art golf club head has an 11.0% decrease in total golf club head MOI when the weight assembly is moved to a most heelward position, and 3.4% decrease when the weight assembly is moved to a most toeward position. 
     Moving the CG  180  of the exemplary golf club head  100  toward the heel  120  or toe  124  of the golf club head  100  contributes to shaping golf ball flight towards a fade or draw bias. Such shot shaping is desirable to help improve a golfer&#39;s shot. However, if an adjustable weight system requires a comparatively large movement of the adjustable weight across the volume of the golf club head, then the CG of the golf club head is moved forwards towards the striking face of the golf club head, and usually moved higher above the sole in the volume of the golf club head. This movement of the CG towards the striking face and higher in the club head volume reduces the combined or total moment of inertia of the golf club head. The reduction of total club head MOI is not desirable, as the forgiveness for off center hits is reduced. Thus, in golf club head having a conventional adjustable weight system, as illustrated in Table 3, the user must choose between shot shaping and forgiveness. Further, in conventional adjustable weight systems, the larger or more distributed weight port structures are permanently placed masses that often offset the effect of the movement of an adjustable weight member to other positions on a golf club head. 
     The weight assembly slot  240  described herein comprises three threaded receivers positioned relatively close to one another. The weight member  370  can be positioned in three different positions within the slot  240 , to influence a straight ball flight, a right to left ball flight, and a left to right ball flight. The combination of a single, smaller slot  240  in the rear portion  128  with a single, heavy weight member  370  leads to improvements in CG movement and MOI preservation. This is achieved by confining the slot  240  to a relatively small arc on the rear  128  of the golf club head  100 . The smaller maximum angular fastener axis separation  520  provides a smaller displacement of the weight member  370  towards the heel  120  or toe  124  of the golf club head  100 , but the heavier weight member  370  counter balances the smaller maximum angular fastener axis separation  520  of the weight member  370 , allowing the user to shape golf ball flight by using a comparatively smaller weight member displacement while also preserving more of the total MOI and forgiveness of the golf club head  100 . 
     Replacement of one or more claimed elements constitutes reconstruction and not repair. Additionally, benefits, other advantages, and solutions to problems have been described with regard to specific embodiments. The benefits, advantages, solutions to problems, and any element or elements that may cause any benefit, advantage, or solution to occur or become more pronounced, however, are not to be construed as critical, required, or essential features or elements of any or all of the claims. 
     As the rules to golf may change from time to time (e.g., new regulations may be adopted or old rules may be eliminated or modified by golf standard organizations and/or governing bodies such as the United States Golf Association (USGA), the Royal and Ancient Golf Club of St. Andrews (R&amp;A), etc.), golf equipment related to the apparatus, methods, and articles of manufacture described herein may be conforming or non-conforming to the rules of golf at any particular time. Accordingly, golf equipment related to the apparatus, methods, and articles of manufacture described herein may be advertised, offered for sale, and/or sold as conforming or non-conforming golf equipment. The apparatus, methods, and articles of manufacture described herein are not limited in this regard. 
     The above examples may be described in connection with a wood-type golf club, the apparatus, methods, and articles of manufacture described herein. Alternatively, the apparatus, methods, and articles of manufacture described herein may be applicable other type of sports equipment such as a hockey stick, a tennis racket, a fishing pole, a ski pole, etc. 
     Moreover, embodiments and limitations disclosed herein are not dedicated to the public under the doctrine of dedication if the embodiments and/or limitations: (1) are not expressly claimed in the claims; and (2) are or are potentially equivalents of express elements and/or limitations in the claims under the doctrine of equivalents.