Golf club head having a lightweight shaft receiving structure

Abstract

Described herein is a golf club head with a lightweight shaft receiving structure. The lightweight shaft receiving structure comprises one or more lightweight components located in low stress areas of the club head. The lightweight components form portions of the shaft receiving structure that would otherwise be formed by a denser body material. The lightweight shaft receiving structure creates discretionary mass that can be redistributed to improve the mass properties of the club head.

Description

[Technical field]

[0001] (Cross-reference priority) This application claims the benefit of U.S. Provisional Application No. 63 / 267,183, filed January 26, 2022, the contents of which are incorporated by reference in their entirety herein.

[0002] The present disclosure relates generally to golf clubs, and more particularly, to golf club heads having lightweight, adjustable shaft receiving structures. [Background technology]

[0003] In the sport of golf, to maximize performance, golf club heads must be customizable to a particular player. One example of customizability in golf club head design is providing golf club heads with loft and / or lie angles tailored to the player. Loft and lie angle adjustability is often achieved through the use of adjustable shaft receiving mechanisms. However, such mechanisms require additional components with significant mass (compared to non-adjustable shaft receiving mechanisms). The inclusion of adjustable components can be redistributed to strategic areas of the club head to optimize the club head's mass characteristics (i.e., center of gravity location and moment of inertia) to improve the club head's performance and reduce the amount of discretionary mass.

[0004] The prior art club head illustrated in FIGS. 1 and 2 includes an adjustable shaft receiving structure 150. The adjustable shaft receiving structure 150 includes a shaft sleeve 166 and a hosel 152. The hosel 152 is configured to receive the shaft sleeve 166, which provides a significant amount of mass to the club head 100. A typical prior art shaft receiving structure 150 includes a hosel 152 and a shaft sleeve 166 insertable into the hosel 152. The shaft sleeve 166 is configured to connect a golf club shaft (not shown) to the club head 100 and provide adjustability for the loft angle and / or lie angle of the club head 100 at address. The hosel 152 can include a hosel bore 156 configured to receive the shaft sleeve 166. The hosel bore 156 defines a hosel bore axis 168 concentric with the hosel bore 156. The hosel 152 can define a hosel bore opening 158 at an upper end of a hosel wall 154. The shaft sleeve 166 and the hosel 152 may have corresponding receiving geometries that allow the shaft sleeve 166 to be removably and adjustably connected within the hosel bore 156. In many cases, the loft angle and / or lie angle of the club head may be adjusted by adjusting the position of the shaft sleeve 166 within the hosel bore 156. The shaft sleeve 166 may be secured to the hosel 152 by a fastener 176. The fastener 176 may extend through a lower opening 174 formed in the shaft receiving structure 150 and connect to a lower end of the shaft sleeve 166. The fastener 176 may removably connect the shaft sleeve 166 to the hosel 152.

[0005] Many prior art shaft receiving structures 150 include several internal components formed by the club head body 101. As shown in FIG. 1, many prior art shaft receiving structures 150 include a hosel tube 160 that extends from a hosel bore opening 158 to a hosel base 162. The hosel tube 160 holds a shaft sleeve 166 in place and seals the hosel bore 156 from the internal cavity 107. In the prior art, the entire hosel 152, the hosel tube 160, and the hosel base 162 are all typically formed integrally with the club head body 101, thus adding significant mass to the shaft receiving structure 150. The shaft sleeve 166 may be secured to the hosel 152 by a fastener 176. The fastener 176 may extend through a lower opening 174 formed in the shaft receiving structure 150 and connect to the lower end of the shaft sleeve 166.

[0006] As shown in Figures 1 and 2, the hosel tube 160 does not contact and support the shaft sleeve 166 when the shaft sleeve 166 is inserted into the hosel bore 156. Instead, the shaft sleeve 166 is primarily supported by the hosel wall 154 at the hosel bore opening 158 and supported by tension with the threaded fastener 176. The head of the threaded fastener 176 is then in contact with the hosel base 162 adjacent the lower opening 174. Stresses imparted to the golf club head 100 through the shaft during use are transferred through the shaft sleeve 166 at the contact point between the hosel bore opening 158 and the hosel base 162. Because the hosel tube 160 is not in contact with the shaft sleeve 166, the hosel tube 160 receives only a small amount of the stress load of a golf swing.

[0007] In the prior art shaft receiving structure 150, the various components described above (i.e., hosel wall 154, hosel tube 160, hosel base 162, shaft sleeve 166, fastener 176, etc.) are formed of steel or other relatively dense metallic materials. Thus, providing a golf club head with an adjustable shaft receiving structure has traditionally reduced the amount of discretionary mass available for improving the mass properties of the club head. There is a need in the art for a shaft receiving structure that allows for loft and lie adjustability, creates discretionary mass that can be redistributed throughout the club head for improved performance, and preserves the structural integrity of the club head. [Brief description of the drawings]

[0008] To facilitate further explanation of the embodiments, the following drawings are provided:

[0009] [Figure 1] 1 is a front cross-sectional view showing a shaft receiving structure of a prior art golf club head.

[0010] [Diagram 2] FIG. 2 is an exploded detailed view of the prior art shaft bearing structure of FIG. 1.

[0011] [Diagram 3] 1 is a front perspective view of a wood-type golf club head according to the present invention;

[0012] [Figure 4] FIG. 4 is a front view of the wood-type golf club head of FIG. 3.

[0013] [Diagram 5] 4 is a heel-side cross-sectional view of the wood-type golf club head of FIG. 3.

[0014] [Figure 6] FIG. 4 is a sole view of the wood-type golf club head of FIG. 3.

[0015] [Figure 7] FIG. 1 is a front cross-sectional view of a lightweight shaft receiving structure including a tube insert and a lower end cap.

[0016] [Figure 8] FIG. 8 is an exploded cross-sectional view of the lightweight shaft support structure of FIG. 7.

[0017] [Figure 9] FIG. 8 is a cross-sectional detail of the lower end cap of FIG.

[0018] [Figure 10] FIG. 11 is a front cross-sectional view showing another embodiment of a lightweight shaft receiving structure including a tube insert and a lightweight collar.

[0019] [Figure 11] FIG. 11 is an exploded cross-sectional view of the lightweight shaft support structure of FIG.

[0020] [Figure 12] FIG. 11 is a detailed exploded view of the lightweight shaft receiving structure of FIG. 10, highlighting the connection between the lightweight collar and the hosel.

[0021] [Figure 13] FIG. 11 is a front cross-sectional view showing another embodiment of a lightweight shaft receiving structure having a hosel insert.

[0022] [Figure 14] FIG. 14 is an exploded cross-sectional view of the lightweight shaft support structure of FIG. 13.

[0023] [Figure 15] FIG. 13 is a front cross-sectional view showing another embodiment of a lightweight shaft receiving structure without a tube insert.

[0024] [Figure 16] 13 is a heel side cross-sectional view of another embodiment of a lightweight shaft receiving structure having an external hosel insert; FIG.

[0025] [Figure 17A] 3 illustrates the internal stresses that occur during impact of a prior art club head with a hosel tube.

[0026] [Figure 17B] Illustrates the internal stresses that occur during impact in a club head similar to that of FIG. 17A, but without the hosel tube.

[0027] [Figure 18A] FIG. 2 is an internal view of a shaft receiving structure of a wood-type golf club head. [Figure 18B] FIG. 2 is an internal view of a shaft receiving structure of a wood-type golf club head.

[0028] Described herein are various embodiments of golf club heads with lightweight, adjustable shaft receiving structures. The lightweight shaft receiving structures have reduced mass creating discretionary mass that can be applied to the club head to improve mass properties such as CG location and moment of inertia. The shaft receiving structures include various components, some of which can be constructed of lightweight materials to reduce the overall mass of the shaft receiving structures. The reduction in mass of the shaft receiving structures creates discretionary mass that can be redistributed to strategic locations to create high performance club heads with improved mass properties.

[0029] In particular, the lightweight shaft receiving structure provides lightweight (i.e., low density) components in areas of the club head that do not experience significant stress loads during the golf swing or upon impact between the club head and the golf ball. In many embodiments, portions of the shaft receiving structure spaced away from the contact points between the hosel and the shaft sleeve and / or the contact points between the hosel base and the fastener typically experience negligible stresses upon impact. Thus, the shaft receiving structure does not rely on any structural components provided in said low stress areas for the structural integrity of the club head. In many embodiments, lightweight components such as lightweight hosel tube inserts, hosel inserts, or end caps can be provided in said areas for purposes other than bearing loads. In some embodiments, certain components typically provided in prior art shaft receiving structures, such as hosel tubes, can be completely eliminated without sacrificing the structural integrity of the club head.

[0030] The lightweight shaft receiving structure provides lightweight components to reduce the overall mass of the shaft receiving structure and create discretionary mass. The lightweight shaft receiving structure can create up to 12 grams more discretionary mass as compared to a similar prior art shaft receiving structure lacking lightweight components. In many embodiments, the lightweight shaft receiving structure has a density of 3 g / cm 3The lightweight shaft receiving structure has a lightweight hosel tube insert that is less than 1.5 mm thick. This seals the hosel bore from the internal cavity without providing significant mass. In other embodiments, the lightweight shaft receiving structure is configured "tubeless" with the hosel tube completely removed, minimizing the mass of the shaft receiving structure. In many embodiments, the discretionary mass created by the lightweight shaft receiving structure provides a club head with improved mass characteristics. In many embodiments, the discretionary mass can be used to lower the CG height and / or modify the CG depth to provide a club head with higher launch, less spin, and / or higher ball speed. In some embodiments, the discretionary mass can be used to provide an increased moment of inertia over a similar club head with a prior art shaft receiving structure.

[0031] (definition) For simplicity and clarity of illustration, the drawings show general structural aspects, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the present invention. Additionally, elements in the drawings are not necessarily drawn to scale. For example, the dimensions of some elements in the figures may be exaggerated relative to other elements to help understand embodiments of the present invention. The same reference numerals in different figures refer to the same elements.

[0032] The terms "lightweight" or "low density" as used herein with respect to components of the shaft-receiving structure refer to components that are constructed of a material that has a lower density than the metallic material that constitutes at least a portion of the club head body.

[0033] The terms "replacing" or "replacing" with respect to lightweight components of a shaft-receiving structure as described herein refer to the ability of the subject lightweight component to form part of a shaft-receiving structure that, in prior art embodiments, would otherwise be formed of a higher density metal club head body material. This disclosure uses the prior art as a reference to illustrate features of the shaft-receiving structure that can be substituted or replaced by the lightweight components described herein.

[0034] The terms "first," "second," "third," "fourth," and the like, in the specification and claims, if any, are used to distinguish between similar elements and are not necessarily used to describe a particular sequence or chronological order. It is to be understood that terms used in this manner may be interchanged under appropriate circumstances, such that the embodiments described herein are capable of operating in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "include" and "have," and variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus having a list of elements is not necessarily limited to those elements and may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus.

[0035] In this specification and claims, terms such as "left," "right," "front," "rear," "upper," "lower," "above," "below," and the like, if any, are used for purposes of description and not necessarily to describe permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances, such that the embodiments of the invention described herein are operable, for example, in orientations other than those illustrated or otherwise described herein.

[0036] The terms "connect," "connected," "connect," "connecting," and the like should be understood broadly and refer to connecting two or more elements or signals in an electrical, mechanical, and / or other manner.

[0037] The term "striking face" refers to the front of the club head that is configured to strike a golf ball. The term striking face can be used interchangeably with "face."

[0038] The term "striking face perimeter" as used herein may refer to the edge of the striking face. The striking face perimeter may be located along the outer edge of the striking face where the curvature deviates from the bulge and / or roll of the striking face.

[0039] The term "geometric center" or "geometric center" of a striking face as described herein may refer to the geometric center of the striking face's perimeter and the midpoint of the face height of the striking face. In the same or other examples, the geometric center may also be centered with respect to an engineered impact zone, which may be defined by an area of ​​grooves on the striking face. As another approach, the geometric center of the striking face may be located according to a definition of a golf governing body, such as the United States Golf Association (USGA).

[0040] The term "ground plane" as used herein may refer to a reference plane associated with the surface on which the golf ball rests. The ground plane may be the horizontal plane that is in contact with the sole at the address position.

[0041] As used herein, the term "loft plane" may refer to a reference plane that is tangent to the geometric center point of the striking face.

[0042] The term "loft angle" as used herein may refer to the angle measured between the loft plane and a plane perpendicular to the ground plane.

[0043] As used herein, the term "face height" may refer to the distance between the top of the striking face perimeter and the bottom of the striking face perimeter measured parallel to the loft plane.

[0044] The term "lie angle" as used herein may refer to the angle between a hosel axis extending through the hosel and the ground plane. The lie angle is measured from a front view.

[0045] The "depth" of the golf club head as described herein may be defined as the dimension from the front to the rear of the golf club head.

[0046] The "height" of a golf club head as described herein may be defined as the dimension from the crown to the sole of the golf club head. In many embodiments, the height of the club head may be measured according to a golf governing body, such as the United States Golf Association (USGA).

[0047] The "length" of a golf club head as described herein may be defined as the dimension of the golf club head from heel to toe. In many embodiments, the length of the club head may be measured according to a golf governing body, such as the United States Golf Association (USGA).

[0048] The "geometric center height" of a fairway-type golf club head as described herein is the height measured perpendicularly from the ground plane to the geometric center point of the golf club head.

[0049] The "leading edge" of the club head described herein may be identified as the sole-most portion of the periphery of the striking face.

[0050] The "XYZ" coordinate system of the golf club head described herein is based on the geometric center of the striking face. The dimensions of the golf club head as described herein may be measured based on the coordinate system as defined below. The coordinate system is described with reference to FIGS. 4 and 5. The geometric center 120 of the striking face 102 defines a coordinate system having an origin located at the geometric center 120 of the striking face 102. The coordinate system defines an X-axis 1040, a Y-axis 1050, and a Z-axis 1060. The X-axis 1040 passes through the geometric center 120 of the striking face 102 in a direction from the heel 104 to the toe 106 of the club head 100. The Y-axis 1050 passes through the geometric center 120 of the striking face 102 in a direction from the crown 110 to the sole 112 of the golf club head 100. The Y-axis 1050 is perpendicular to the X-axis 1040. The Z-axis 1060 extends through the geometric center 120 of the striking face 102 in a direction from the front end 108 toward the back end 111 of the golf club head 100. The Z-axis 1060 is perpendicular to both the X-axis 1040 and the Y-axis 1050.

[0051] The term or phrase "center of gravity location" or "CG location" may refer to the location of the club head center of gravity (CG) 199 relative to an XYZ coordinate system, with the CG location being characterized by location along the X-axis 1040, the Y-axis 1050, and the Z-axis 1060. The term "CGx" may refer to the CG location along the X-axis 1040, measured from the origin 120. The term "CG height" may refer to the CG location along the Y-axis 1050, measured from the origin 120. The term "CGy" may be synonymous with CG height. The term "CG depth" may refer to the CG location along the Z-axis 1060, measured from the origin 120. The term "CGz" may be synonymous with CG depth.

[0052] The XYZ coordinate system of the golf club head described herein defines an XY plane extending through the X-axis 1040 and the Y-axis 1050. The coordinate system defines an XZ plane extending through the X-axis 1040 and the Z-axis 1060. The coordinate system further defines a YZ plane extending through the Y-axis 1050 and the Z-axis 1060. The XY, XZ, and YZ planes are all perpendicular to one another and intersect at a coordinate system origin located at the geometric center 120 of the striking face 102. In these or other embodiments, the golf club head 100 can be viewed from a front view when the striking face 102 is viewed perpendicular to the XY plane. Additionally, in these or other embodiments, the golf club head 100 can be viewed from a side view, or a cross-sectional side view, when the heel 104 is viewed perpendicular to the YZ plane.

[0053] As shown in Figures 4 and 5, the golf club head 100 further comprises a coordinate system centered on the center of gravity 199. The coordinate system comprises an X'-axis 1070, a Y'-axis 1080, and a Z'-axis 1090. The X'-axis 1070 extends in a heel-to-toe direction. The X'-axis 1070 is positive toward the heel 104 and negative toward the toe 106. The Y'-axis 1080 extends in a sole-to-crown direction and is perpendicular to both the Z'-axis 1090 and the X'-axis 1070. The Y'-axis 1080 is positive toward the crown 110 and negative toward the sole 112. The Z'-axis 1090 extends in a front-to-rear direction, is parallel to the ground plane, and is perpendicular to both the X'-axis 1070 and the Y'-axis 1080. The Z'-axis 1090 is positive toward the striking face 102 and negative toward the rear 111.

[0054] The term or phrase "Moment of Inertia" (hereinafter "MOI") as defined herein may refer to values ​​measured on the CG 199. The term "Ixx" may refer to the MOI measured in a heel-to-toe direction about the X'-axis 1070. The term "Iyy" may refer to the MOI measured in a sole-to-crown direction about the Y'-axis 1080. The term "Izz" may refer to the MOI measured in a front-to-back direction about the Z'-axis 1090. The MOI values ​​Ixx, Iyy, Izz determine how forgiving the club head 100 is for off-center impacts with a golf ball.

[0055] A "driver-type golf club head," also referred to as a driver, as described herein can be defined by certain dimensional ranges. In particular, a driver as described with respect to the invention disclosed herein includes a loft angle and a volume within the ranges defined below. The ranges defined below limit a driver-type golf club head to a driver-type club head. In other words, a driver-type golf club head cannot be a fairway-type, hybrid-type, iron-type, or putter-type golf club head.

[0056] The "loft angle" of a driver as defined herein can be less than about 16 degrees, less than about 15 degrees, less than about 14 degrees, less than about 13 degrees, less than about 12 degrees, less than about 11 degrees, or less than about 10 degrees.

[0057] The "volume" of a driver as defined herein is approximately 300 cm 3 Larger, about 350cm 3 Larger, about 400cm 3 Larger, about 425cm 3 Larger, about 450cm 3 Larger, about 475cm 3 Larger than about 500cm 3 , approx. 525cm 3 Larger, about 550cm 3 Larger, about 575cm 3Larger, about 600cm 3 Larger, about 625cm 3 Larger, about 650cm 3 Larger, about 675cm 3 Larger or about 700cm 3 It can get bigger.

[0058] A "fairway-type golf club head" as defined herein is a club head having a particular loft, volume, and dimensions that can be defined by particular dimensional ranges. In particular, the fairway-type club heads described with respect to the invention disclosed herein include loft angles and volumes within the ranges defined below. The ranges defined below limit a fairway-type golf club head to a fairway-type club head. In other words, a fairway-type golf club head cannot be a driver-type, hybrid-type, iron-type, or putter-type golf club head.

[0059] The "loft angle" of a fairway-type club head as defined herein can be less than about 35 degrees, less than about 34 degrees, less than about 33 degrees, less than about 32 degrees, less than about 31 degrees, or less than about 30 degrees. In some embodiments, the loft angle of a fairway-type golf club head can be greater than about 12 degrees, greater than about 13 degrees, greater than about 14 degrees, greater than about 15 degrees, greater than about 16 degrees, greater than about 17 degrees, greater than about 18 degrees, greater than about 19 degrees, or greater than about 20 degrees. For example, in some embodiments, the loft angle of a fairway-type golf club head can be between 14 degrees and 35 degrees, between 15 degrees and 35 degrees, between 20 degrees and 35 degrees, or between 12 degrees and 30 degrees.

[0060] The "volume" of a fairway club as defined in this book is approximately 170 cm 3 Less than 180cm 3 Less than 190cm 3 Less than or about 200cm 3 However, the volume of a fairway club is 160 cm 3In some embodiments, the volume of a fairway-type club head is about 150 cm 3 From 200cm 3 Between, about 160cm 3 From 170cm 3 Between, about 160cm 3 From 180cm 3 Between or about 170cm 3 From 190cm 3 The volume of a fairway club can be between 200cm 3 In one exemplary embodiment, the volume of a fairway type club is 169 cm 3 It is.

[0061] A "hybrid-type golf club head" as defined herein is a club head having a particular loft, volume, and dimensions that can be defined by particular dimensional ranges. In particular, a fairway-type club head as described with respect to the invention disclosed herein has a loft angle and volume within the ranges defined below. The ranges defined below limit a hybrid-type golf club head to a hybrid-type club head. In other words, a hybrid-type golf club head cannot be a driver-type, fairway-type, iron-type, or putter-type golf club head.

[0062] The "loft angle" of a hybrid-type club head, as defined herein, can be less than about 40 degrees, less than about 39 degrees, less than about 38 degrees, less than about 37 degrees, less than about 36 degrees, less than about 35 degrees, less than about 34 degrees, less than about 33 degrees, less than about 32 degrees, less than about 31 degrees, or less than about 30 degrees. Additionally, in many embodiments, the loft angle of a hybrid-type club head can be greater than about 16 degrees, greater than about 17 degrees, greater than about 18 degrees, greater than about 19 degrees, greater than about 20 degrees, greater than about 21 degrees, greater than about 22 degrees, greater than about 23 degrees, greater than about 24 degrees, or greater than about 25 degrees.

[0063] The "volume" of a hybrid-type club head as defined herein can be less than about 200 cc, less than about 175 cc, less than about 150 cc, less than about 125 cc, less than about 100 cc, or less than about 75 cc. In some embodiments, the volume of a hybrid-type club head can be about 100 cc to 150 cc, about 75 cc to 150 cc, about 100 cc to 125 cc, or about 75 cc to 125 cc.

[0064] (explanation) I. General golf club head structure Described herein are various embodiments of a lightweight shaft receiving structure that can be applied to a wood-type golf club head to create discretionary mass and improve the mass properties of the club head. The lightweight shaft receiving structure can be applied to a wood-type golf club head. Referring to the drawings, a club head 100 is used to illustrate the general characteristics of any club head to which any of the lightweight shaft receiving structures described below can be applied. FIGS. 3-6 show a wood-type golf club head 100 in various views in schematic form. Specifically, FIG. 3 shows a front perspective view of the wood-type club head 100. The club head 100 can include a striking face 102 and a body 101 secured together to define a substantially closed / hollow interior cavity 107 (shown in FIG. 5). The club head 100 includes a crown 110, a sole 112 opposite the crown 110, a heel 104, a toe 106 opposite the heel 104, a front portion 108, and a rear portion 111 opposite the front portion 108. The body 101 may further include a skirt 114 located adjacent between the crown 110 and the sole 112. The skirt 114 extends from near the heel 104 to near the toe 106 of the club head 100.

[0065] As described in this disclosure, the club head 100 is a wood-type club head, such as a driver, a fairway wood, or a hybrid. Although various illustrations of a fairway wood-type club head are depicted, it should be noted that any of the lightweight shaft receiving structures described herein may be applied to any wood-type club head, including a driver-type or hybrid-type club head. The striking face 102 and the body 101 may define an interior cavity 107 of the club head 100. The body 101 may extend across the periphery of the crown 110, the sole 112, the heel 104, the toe 106, the rear 111, and the front 108. In these embodiments, the body 101 defines an opening in the front 108 of the club head 100, and the striking face 102 is disposed within the opening to form the club head 100. In other embodiments, the striking face 102 may extend across the periphery of the front 108 and may include a return portion 122 extending rearwardly from the striking face 102. The return portion 122 can extend across at least one of the crown 110, the sole 112, the heel 104, and the toe 106. In embodiments having a return portion 122, the return portion 122 of the striking face 102 is secured to the body 101 to form the club head 100. In these embodiments, the club head 100 can resemble a cup-face or face-wrap design, as shown in FIG.

[0066] As described above and shown in Figures 1 and 2, the club head 100 includes a shaft receiving structure 150. The shaft receiving structure 150 includes a hosel 152. The hosel 152 can receive a shaft sleeve 166 and a golf shaft (not shown). The shaft sleeve 166 can be connected to an end of the golf shaft (not shown). The shaft sleeve 166 can be connected to the hosel 152 in multiple configurations, thereby allowing the golf shaft to be secured to the hosel 152 at multiple angles.

[0067] 5 and 6, the club head 100 can include a weight port 125 configured to receive a removable weight 126. In many embodiments, the weight port 125 can be located proximate the rear 111, in the sole 112, and / or in the skirt 114. The club head 100 can further include a mass pad 163 or weight pad (hereinafter "mass pad"). In many embodiments, the mass pad 163 can be located on the sole 112 and in the interior cavity 107. In other embodiments, the mass pad 163 can be located on the sole 112 and skirt 114, as well as in the interior cavity 107. In still other embodiments, the club head 100 can include one or more weight ports 125 and one or more mass pads 163. The removable weights 126 and mass pads 163 can adjust moment of inertia (MOI) characteristics and center of gravity (CG) location. In many embodiments, the discretionary mass created by the lightweight shaft receiving structures described herein can be redistributed by adding mass to the removable weights 126 or mass pads 163 to improve the mass properties of the club head.

[0068] In many embodiments, a substantial portion of the club head body 101 may be formed from a metallic material. The lightweight shaft receiving structures described herein may be applied to club heads 100 having a body 101 that is entirely metallic or made from multiple materials. In certain embodiments, the lightweight shaft receiving structures described herein may be applied to club heads 100 in which at least a portion of the body 101 is formed from a lightweight, non-metallic material. However, in the following description of various shaft receiving structures, the term "body material" is used in reference to a metallic material that forms a portion of the body.

[0069] Body materials may include, but are not limited to, steel, steel alloys, stainless steel alloys, nickel, nickel alloys, cobalt, cobalt alloys, titanium alloys, amorphous metal alloys, or other similar materials. For example, the body material may include, but is not limited to, Ti-8Al-1Mo-1V alloy, 17-4 stainless steel, C300, C350, Ni-Co-Cr-steel alloy, 565 steel, AISI type 304 or AISI type 630 stainless steel, 17-4 stainless steel, titanium alloys such as, but not limited to, Ti-6-4, Ti-3-8-6-4-4, Ti-10-2-3, Ti15-3-3, Ti15-5-3, Ti185, Ti6-6-2, Ti-7s, Ti-9s, Ti-92, T9s+ or Ti-8-1-1 titanium alloys, amorphous metal alloys or other similar metals. The body material has a density greater than the lightweight material used to provide the lightweight components of the shaft receiving structure. Generally, the density of the body material is about 4 g / cm. 3 from about 10g / cm 3 In many of the embodiments of the lightweight shaft receiving structure described below, the shaft receiving structure may be formed from a combination of the body material and the lightweight material.

[0070] (II. Lightweight shaft support structure) In many prior art club heads, the adjustable shaft receiving structure includes various components integrally formed from the body material. The material of the shaft receiving structure is typically the same material as at least a majority of the club head body, typically a material suitable for casting, such as steel or a titanium alloy. In many prior art multi-material club heads, the shaft receiving structure is integrally formed with the metal components of the body and has the same metal material as the body. Metal body material is required in many parts of the body (sole, crown return, rear, etc.) for durability and mass distribution. However, certain parts of the shaft receiving structure (i.e., hosel tube) do not bear a significant portion of the impact loads and therefore do not need to be formed entirely from the body material. As discussed in more detail below, the shaft receiving structure does not have the same strength requirements as the sole, crown return, or other parts of the club head formed by the body. As an example, stresses exerted on the golf club head through the shaft during use are transferred through the shaft sleeve at the junction of the hosel bore opening and the hosel base. Because the hosel tube is not in contact with the shaft sleeve, it bears only a small amount of the stress load of the golf swing. Thus, portions of the shaft receiving structure, such as the hosel tube, can be provided from lightweight materials without compromising the structural integrity of the golf club head.

[0071] When the club head is used to strike a golf ball, the portions of the golf club head in and around the shaft-receiving structure are subjected to less stress and therefore do not require the same material properties as the portions of the golf club head that are subjected to greater stress during impact with a golf ball. As a result, materials with lower material strength and lower density (lighter weight) can be substituted for the portions of the shaft-receiving structure that are subjected to the lower stresses.

[0072] The lightweight, adjustable shaft receiving structure creates discretionary mass by replacing portions of the shaft receiving structure that are typically formed from the body material with lightweight components (or, in some cases, eliminating said components entirely). In many embodiments, portions of the hosel body, hosel transition, hosel tube, and / or hosel base can be constructed from lightweight materials. Such components can be constructed from lightweight materials (i.e., materials that are lighter than the material of the body) to reduce the mass of the shaft receiving structure.

[0073] The lightweight shaft receiving structure may have one or more parts or components constructed of a lightweight material having a density lower than the density of the body material. In many embodiments, the one or more parts or components of the lightweight shaft receiving structure may be formed of a polymeric material, a composite material, or a lightweight metallic material having a density lower than the density of the metal forming the body. In many embodiments, the one or more parts or components of the lightweight shaft receiving structure may be formed of a material including, but not limited to, a polymeric resin or a fiber-reinforced polymeric resin. The polymeric resin may include a thermoset resin, a thermoplastic resin, a filled thermoplastic, a fiber-reinforced composite, a thermoplastic polyurethane (TPU), or a thermoplastic elastomer (TPE). For example, the resin may include polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyimide, polyamide such as PA6 or PA66, polyamideimide, polyphenylene sulfide (PPS), polycarbonate, polyvinyl chloride (PVC), silicone or silicone plastic, nylon, nylon 6, nylon 66, ABS, polystyrene, acrylic, engineering polyurethane, and / or other similar materials. In some embodiments, one or more portions or components of the lightweight shaft receiving structure may be formed from a lightweight metallic material, including, but not limited to, aluminum or an aluminum alloy, magnesium or a magnesium alloy, and / or any other suitable lightweight alloy. Any of the components described in the following embodiments as being formed from a "lightweight" material may include any one or combination of the above materials.

[0074] One or more portions or components of the lightweight shaft receiving structure may have a density significantly lower than the density of the body material. In many embodiments, the density of the lightweight material forming one or more lightweight components of the shaft receiving structure is about 3 g / cm 3 In many embodiments, the density of the lightweight material forming one or more of the lightweight components can be less than 2.75 g / cm3 Less than 2.50g / cm 3 Less than 2.25g / cm 3 , 2.00g / cm 3 Below 1.75g / cm 3 Below 1.50g / cm 3 Below 1.25g / cm 3 Below 1.00g / cm 3 Below 0.75g / cm 3 Less than or equal to 0.50g / cm 3 By forming a part of the shaft receiving structure, which would otherwise be formed from the body material, from a lightweight material, the mass of the entire shaft receiving structure can be reduced.

[0075] Thus, the benefits of the lightweight shaft receiving structure are only realized when the various embodiments of the shaft receiving structure described herein are applied to a golf club head having an at least partially metallic body. For example, the lightweight shaft receiving structure is applicable and beneficial in a fully metallic club head or in a multi-component club head that typically includes metallic components forming the shaft receiving structure. For example, the lightweight shaft receiving structure would not be particularly beneficial if applied to a fully composite golf club head because the shaft receiving structure does not have a high density body material to replace the lightweight material. It should be noted that although the shaft receiving structures described herein are illustrated in a multi-material club head body, any of the foregoing shaft receiving structures may alternatively be applied to a single material or fully metallic club head body.

[0076] The lightweight shaft receiving structure may be formed of a combination of body material and lightweight material. In this manner, the body material may still form certain portions of the shaft receiving structure, but the remainder of the shaft receiving structure may be formed of separate components having the lightweight material. The inclusion of the lightweight material may create discretionary mass compared to a shaft receiving structure formed solely of body material.

[0077] The advantage of the lightweight shaft receiving structure is the creation of discretionary mass that can be redistributed throughout the golf club head. The lightweight shaft receiving structure can create discretionary mass between 3 grams and 12 grams. In some embodiments, the lightweight shaft receiving structure can create discretionary mass between 3 grams and 6 grams, between 4 grams and 7 grams, between 5 grams and 8 grams, between 6 grams and 9 grams, between 7 grams and 10 grams, between 8 grams and 11 grams, or between 9 grams and 12 grams. In some embodiments, the lightweight shaft receiving structure can create discretionary mass greater than 3 grams, greater than 4 grams, greater than 5 grams, greater than 6 grams, greater than 7 grams, greater than 8 grams, greater than 8 grams, greater than 10 grams, greater than 11 grams, or greater than 12 grams.

[0078] Discretionary mass can be redistributed to advantageous locations in the golf club head to improve performance. Discretionary mass can be redistributed to modify the mass characteristics of the club head, such as to provide a desired CG location and / or increase the MOI.

[0079] In many embodiments, the discretionary mass resulting from the inclusion of a lightweight shaft receiving structure can be redistributed to provide a lower CG location (i.e., lower CGy). In many embodiments, discretionary mass can be added to a mass pad on the sole to lower the CG location. Thus, the club head can have a substantially heavy mass pad on the sole. In many embodiments, the mass pad can have a mass between 15 grams and 40 grams. In some embodiments, the mass pad can have a mass between 15 grams and 20 grams, between 20 grams and 25 grams, between 25 grams and 30 grams, between 30 grams and 35 grams, or between 35 grams and 40 grams. In some embodiments, the mass pad can have a mass greater than 15 grams, greater than 20 grams, greater than 25 grams, greater than 30 grams, greater than 35 grams, or greater than 40 grams.

[0080] In many embodiments, the discretionary mass resulting from the inclusion of a lightweight shaft receiving structure can lead to an increased MOI of the club head over a similar club head having a prior art shaft receiving structure. By including the lightweight shaft receiving structure disclosed herein, a club head having a high MOI is provided. In many embodiments, the discretionary mass can be added to a removable weight near the rear of the club head. By redistributing the mass saved by the lightweight shaft receiving structure to the removable weight, the MOI of the club head can be increased. Thus, the club head can include a substantially heavy removable weight near the rear. In many embodiments, the removable weight can include a mass between 1.0 grams and 35 grams. In some embodiments, the removable weight can have a mass in the range of 1.0 grams and 20 grams, or 20 grams and 35 grams. In some embodiments, the removable weight can have a mass in the range of 1.0 grams to 15 grams, 5 grams to 20 grams, 10 grams to 25 grams, 15 grams to 30 grams, or 20 grams to 35 grams. For example, the mass of the removable weight can be 1.0 grams, 1.5 grams, 2.0 grams, 3.0 grams, 4.0 grams, 5.0 grams, 6.0 grams, 7.0 grams, 8.0 grams, 9.0 grams, 10 grams, 11 grams, 12 grams, 13 grams, 14 grams, 15 grams, 16 grams, 17 grams, 18 grams, 19 grams, 20 grams, 21 grams, 22 grams, 23 grams, 24 grams, 25 grams, 26 grams, 27 grams, 28 grams, 29 grams, 30 grams, 31 grams, 32 grams, 33 grams, 34 grams, or 35 grams.

[0081] In many embodiments, the driver-type club head with the lightweight shaft receiving structure has a weight of 3000 g*cm 2 From 4800g*cm 2In some embodiments, the driver-type club head with the lightweight shaft receiving structure has an Ixx moment of inertia of between 3000 g*cm 2 and 3200g*cm 2 Between 3200g*cm 2 and 3400g*cm 2 Between 3400g*cm 2 and 3600g*cm 2 Between 3600g*cm 2 and 3800g*cm 2 Between 3800g*cm 2 and 4000g*cm 2 Between 4000g*cm 2 and 4200g*cm 2 Between 4200g*cm 2 and 4400g*cm 2 Between 4400g*cm 2 and 4600g*cm 2 Between 4600g*cm 2 and 4800g*cm 2 The moment of inertia Ixx can be between

[0082] In some embodiments, the driver-type club head with the lightweight shaft receiving structure has a weight of 4500 g*cm 2 and 6000g*cm 2 In some embodiments, the driver-type club head with the lightweight shaft receiving structure has an Iyy moment of inertia between 4500 g*cm 2 and 5000g*cm 2 Between 4600g*cm 2 and 5100g*cm 2 Between 4700g*cm 2 and 5200g*cm 2 Between 4800g*cm 2 and 5300g*cm 2 Between 4900g*cm 2 and 5400g*cm 2 Between 5000g*cm 2 and 5500g*cm 2 Between 5100g*cm 2 and 5600g*cm2 Between 5200g*cm 2 and 5700g*cm 2 Between 5300g*cm 2 and 5800g*cm 2 Between 5400g*cm 2 and 5900g*cm 2 Between 5500g*cm 2 and 6000g*cm 2 The moment of inertia between the yyy and the yyy axis can be set to Iyy.

[0083] In some embodiments, the driver-type club head with the lightweight shaft receiving structure has a weight of 2400 g*cm 2 and 3000g*cm 2 In some embodiments, the driver-type club head having the lightweight shaft receiving structure has an Izz moment of inertia of between 2400 g*cm 2 and 2500g*cm 2 Between 2500g*cm 2 and 2600g*cm 2 Between 2600g*cm 2 and 2700g*cm 2 Between 2700g*cm 2 and 2800g*cm 2 Between 2800g*cm 2 and 2900g*cm 2 Between 2900g*cm 2 and 3000g*cm 2 It can have a moment of inertia Izz between.

[0084] In many embodiments, a fairway wood type club head with a lightweight shaft receiving structure has a weight of 1400 g*cm 2 and 2200g*cm 2 In some embodiments, a fairway wood type club head having a lightweight shaft receiving structure can have an Ixx moment of inertia between 1400 g*cm 2 and 1500g*cm 2 Between 1500g*cm 2 and 1600g*cm 2Between 1600g*cm 2 and 1700g*cm 2 Between 1700g*cm 2 and 1800g*cm 2 Between 1800g*cm 2 and 1900g*cm 2 Between 1900g*cm 2 and 2000g*cm 2 Between 2000g*cm 2 and 2100g*cm 2 Between 2100g*cm 2 and 2200g*cm 2 The moment of inertia Ixx can be between

[0085] In some embodiments, a fairway wood type club head having a lightweight shaft receiving structure has a weight of 2800 g*cm 2 and 4000g*cm 2 In some embodiments, a fairway wood type club head having a lightweight shaft receiving structure may have a moment of inertia between 2900 g*cm 2 and 4000g*cm 2 Between 3000g*cm 2 and 3200g*cm 2 Between 3100g*cm 2 and 3300g*cm 2 Between 3200g*cm 2 and 3400g*cm 2 Between 3300g*cm 2 and 3500g*cm 2 Between 3400g*cm 2 and 3600g*cm 2 Between 3500g*cm 2 and 3700g*cm 2 Between 3600g*cm 2 and 3800g*cm 2 Between 3700g*cm 2 and 3900g*cm 2 Between 3800g*cm 2 and 4000g*cm 2 The moment of inertia between the yyy and the yyy axis can be set to Iyy.

[0086] In some embodiments, a fairway wood type club head having a lightweight shaft receiving structure has a weight of 1600 g*cm 2 and 2400g*cm 2 In some embodiments, a fairway wood type club head having a lightweight shaft receiving structure may have an Izz moment of inertia between 1600 g*cm 2 and 1700g*cm 2 Between 1700g*cm 2 and 1800g*cm 2 Between 1800g*cm 2 and 1900g*cm 2 Between 1900g*cm 2 and 2000g*cm 2 Between 2000g*cm 2 and 2100g*cm 2 Between 2100g*cm 2 and 2200g*cm 2 Between 2200g*cm 2 and 2300g*cm 2 Between 2300g*cm 2 and 2400g*cm 2 It is possible to provide a moment of inertia Izz between the two.

[0087] In many embodiments, the hybrid club head with the lightweight shaft receiving structure has a weight of 750 g*cm 2 and 1000g*cm 2 In some embodiments, the hybrid club head with the lightweight shaft receiving structure can have an Ixx moment of inertia between 750 g*cm 2 and 800g*cm 2 Between 800g*cm 2 and 850g*cm 2 Between 850g*cm 2 and 900g*cm 2 Between 900g*cm 2 and 950g*cm 2 Between 950g*cm 2 and 1000g*cm 2The moment of inertia Ixx can be between

[0088] In some embodiments, the hybrid club head with the lightweight shaft receiving structure has a weight of 2500 g*cm 2 and 3200g*cm 2 In some embodiments, the hybrid type club head with the lightweight shaft receiving structure can have an Iyy moment of inertia between 2500 g*cm 2 and 2600g*cm 2 Between 2600g*cm 2 and 2700g*cm 2 Between 2700g*cm 2 and 2800g*cm 2 Between 2800g*cm 2 and 2900g*cm 2 Between 2900g*cm 2 and 3000g*cm 2 Between 3000g*cm 2 and 3100g*cm 2 Between 3100g*cm 2 and 3200g*cm 2 The moment of inertia between the yyy and the yyy axis can be set to Iyy.

[0089] In some embodiments, the hybrid club head with the lightweight shaft receiving structure has a weight of 2200 g*cm 2 and 3000g*cm 2 In some embodiments, the hybrid club head with the lightweight shaft receiving structure has an Izz moment of inertia between 2200 g*cm 2 and 2300g*cm 2 Between 2300g*cm 2 and 2400g*cm 2 Between 2400g*cm 2 and 2500g*cm 2 Between 2500g*cm 2 and 2600g*cm 2 Between 2600g*cm 2 and 2700g*cm 2 Between 2700g*cm 2and 2800g*cm 2 Between 2800g*cm 2 and 2900g*cm 2 Between 2900g*cm 2 and 3000g*cm 2 It is possible to provide a moment of inertia Izz between the two.

[0090] Additionally, the discretionary mass created by the inclusion of a lightweight shaft receiving structure allows for mass to be relocated to provide a more desirable CG location. In many embodiments, the discretionary mass can be relocated to lower the CG height and / or deepen the CG depth. Lowering the CG height can improve the performance characteristics of the club head by increasing launch angle, decreasing ball spin rate, and / or improving ball speed.

[0091] In many embodiments, a driver-type club head with a lightweight shaft-receiving structure can have a CG height between 0 inches and -0.300 inches. In some embodiments, a driver-type club head with a lightweight shaft-receiving structure can have a CG height between 0 inches and -0.050 inches, between -0.050 inches and -0.100 inches, between -0.100 inches and -0.150 inches, between -0.150 inches and -0.200 inches, between -0.200 inches and -0.250 inches, or between -0.250 inches and -0.300 inches.

[0092] In many embodiments, a driver-type club head with a lightweight shaft-receiving structure can have a CG depth between 1.25 inches and 2.00 inches. In some embodiments, a driver-type club head with a lightweight shaft-receiving structure can have a CG depth between 1.25 inches and 1.75 inches, between 1.30 inches and 1.80 inches, between 1.35 inches and 1.85 inches, between 1.40 inches and 1.90 inches, between 1.45 inches and 1.95 inches, or between 1.50 inches and 2.00 inches.

[0093] In many embodiments, a fairway wood type club head with a lightweight shaft receiving structure can have a CG height of between -0.140 inches and -0.200 inches. In some embodiments, a fairway wood type club head with a lightweight shaft receiving structure can have a CG height of between -0.140 inches and -0.145 inches, between -0.145 inches and -0.150 inches, between -0.150 inches and -0.155 inches, between -0.155 inches and -0.160 inches, between -0.160 inches and -0.165 inches, between -0.165 inches and -0.170 inches, between -0.170 inches and -0.175 inches, between -0.175 inches and -0.180 inches, between -0.180 inches and -0.185 inches, between -0.185 inches and -0.190 inches, between -0.190 inches and -0.195 inches, or between -0.195 inches and -0.200 inches.

[0094] In many embodiments, a fairway wood type club head with a lightweight shaft receiving structure can have a CG depth between 1.00 inches and 1.50 inches. In some embodiments, a fairway wood type club head with a lightweight shaft receiving structure can have a CG depth between 1.00 inches and 1.05 inches, between 1.05 inches and 1.10 inches, between 1.10 inches and 1.15 inches, between 1.15 inches and 1.20 inches, between 1.20 inches and 1.25 inches, between 1.25 inches and 1.30 inches, between 1.30 inches and 1.35 inches, between 1.35 inches and 1.40 inches, between 1.40 inches and 1.45 inches, or between 1.45 inches and 1.50 inches.

[0095] In many embodiments, a hybrid-type club head with a lightweight shaft receiving structure can have a CG height between -0.220 inches and -0.320 inches. In some embodiments, a hybrid-type club head with a lightweight shaft receiving structure can have a CG height between -0.220 inches and -0.230 inches, between -0.230 inches and -0.240 inches, between -0.240 inches and -0.250 inches, between -0.250 inches and -0.260 inches, between -0.260 inches and -0.270 inches, between -0.270 inches and -0.280 inches, between -0.280 inches and -0.290 inches, between -0.290 inches and -0.300 inches, between -0.300 inches and -0.310 inches, or between -0.310 inches and -0.320 inches.

[0096] In many embodiments, a hybrid-type club head with a lightweight shaft-receiving structure can have a CG depth between 0.900 inches and 1.25 inches. In some embodiments, a hybrid-type club head with a lightweight shaft-receiving structure can have a CG depth between 0.900 inches and 1.00 inches, between 0.925 inches and 1.025 inches, between 0.950 inches and 1.050 inches, between 0.975 inches and 1.075 inches, between 1.00 inches and 1.100 inches, between 1.025 inches and 1.125 inches, between 1.050 inches and 1.150 inches, between 1.075 inches and 1.175 inches, between 1.100 inches and 1.200 inches, between 1.125 inches and 1.225 inches, or between 1.150 inches and 1.250 inches.

[0097] A lightweight shaft receiving structure can reduce the mass of portions of the prior art shaft receiving structure that do not provide structural support. With reference to Figures 17A and 17B, certain portions of the prior art shaft receiving structure experience negligible stress loads during impact. With reference to Figure 17A, the highest stresses during impact occur on the striking face near the center of the striking face. Areas of gradually lower stresses during impact are shown around the highest stress areas, as shown by the change in cross-hatching pattern. The rearmost portion of the golf club head and the shaft receiving structure within the golf club head share a lighter cross-hatching pattern, which indicates the area of ​​lowest stress during impact. As shown in Figure 17B, even with the hosel tube 160 removed, the shaft receiving structure within the golf club head still experiences the lowest stress during impact.

[0098] Also, some embodiments of the shaft receiving structure have portions that are not required to hold the golf shaft in the hosel bore. Referring to Figures 18A and 18B, when the shaft sleeve 166 is connected to the golf club head 100, the shaft sleeve 166 is held in tension by the downward force applied by the threaded fastener 176 being tightened. The force on the upper portion of the shaft sleeve 166 can be analyzed by simplifying the contact between the upper portion of the shaft sleeve 166 and the upper portion of the hosel wall 154 (proximate the hosel bore opening 158) as occurring at the upper contact surface 186. The force on the lower portion of the shaft sleeve 166 can be analyzed by simplifying the contact of the lower portion of the shaft sleeve 166 as occurring at the lower contact surface 187. Figure 18B shows that the force acting on the upper portion of the shaft sleeve 166 is offset or balanced at the top end of the hosel wall 154 (proximate the hosel bore opening 158), which does not involve the hosel tube 160. 18B further illustrates that the forces acting on the lower portion of the shaft sleeve 166 are offset or balanced at the hosel base 162, again without the involvement of the hosel tube 160. This indicates that the hosel tube 160 does not provide the support necessary to hold the shaft within the hosel of the golf club head 100.

[0099] Various embodiments of the shaft receiving structure with lightweight components are described in further detail below. Various embodiments are differentiated with respect to the portions of the prior art shaft receiving structure that are replaced or completely removed by the lightweight components. Various embodiments are further differentiated by the overall amount of discretionary mass that is created compared to the prior art shaft receiving structure. In many embodiments, some or all of the mass of the hosel, hosel wall, hosel tube, and / or hosel base can be replaced with lightweight materials or components. Different embodiments include different combinations of shaft receiving structure portions that are replaced by lightweight components. Different embodiments balance the desire to create the maximum amount of discretionary mass with the need to provide loft and lie angle adjustability, the need to seal internal cavities, and the need for a simple manufacturing and / or assembly process. Further advantages of the lightweight shaft receiving structure can include the elimination of expensive body material that is replaced with the lightweight components. In this manner, by providing a lightweight shaft receiving structure, the manufacturing costs of the club head can be reduced.

[0100] (III. Lightweight Shaft Support Structure with Lower End Cap) 7-9 illustrate a first embodiment of a wood-type golf club head including a lightweight, adjustable shaft receiving structure 250 that replaces the hosel tube, hosel base, and a portion of the hosel wall 254 with lightweight components. Such lightweight components can be formed from a material that is less dense than the material of the body 201, such as the lightweight materials described above. The lightweight shaft receiving structure 250 can have a mass that is reduced by 3-12 grams compared to a similar shaft receiving structure formed entirely from the body material. Reducing the mass of the shaft receiving structure 250 by forming the components from the lightweight material rather than the body material allows discretionary mass to be redistributed to other areas of the club head 200 to improve mass properties and performance.

[0101] Referring to FIG. 7, the shaft receiving structure 250 includes a lightweight tube insert 230 that replaces the entire hosel tube and a portion of the hosel wall 254. In many embodiments, the tube insert 230 is a fully cylindrical tube located within the internal cavity 207. The tube insert 230 is formed as a separate component from the hosel 252 and inserted into the internal cavity 207 during manufacturing. The tube insert 230 can extend from near the hosel bore opening 258 to the hosel base 262. The tube insert 230 reduces mass by replacing the mass of the hosel tube and at least a portion of the mass of the hosel wall 254 with a less dense material. As shown in FIG. 7, the tube insert 230 can replace a portion of the hosel wall 254 so that the hosel wall 254 can be thinned. As the tube insert 230 is located within the internal cavity 207, it replaces a majority of the inner surface of the hosel wall 254. As shown in FIG. 7 , the hosel wall 254 forms an upper hosel wall 280 adjacent the hosel bore opening 258. In many embodiments, the tube insert 230 does not form any portion of the upper hosel wall 280 or the hosel bore opening 258. In this manner, the upper hosel wall 280 can be formed entirely by the hosel 252, which is part of the club head body 201. Any receiving shape required for adjustability of the shaft receiving structure 250 can be formed by the upper hosel wall 280. For example, in some embodiments, the upper hosel wall 280 can form one or more lobes configured to receive one or more surface features of the shaft sleeve 266 and provide adjustability for the loft angle and / or lie angle of the club head. The tube insert 230 can extend from just below the upper hosel wall 280 to the hosel base 262.

[0102] The tube insert 230 has an upper end 231 proximate the hosel wall upper portion 280 and a lower end 232 proximate the hosel base 262. In many embodiments, the tube insert 230 can have a tube insert length measured parallel to the hosel bore axis 268 from the upper end 231 to the lower end 232. In many embodiments, the length of the tube insert can be between 1.00 inches and 1.50 inches. In some embodiments, the length of the tube insert can be between 1.00 inches and 1.10 inches, between 1.10 inches and 1.20 inches, between 1.20 inches and 1.30 inches, between 1.30 inches and 1.40 inches, or between 1.40 inches and 1.50 inches.

[0103] In many embodiments, the length of the tube insert 230 can be further characterized with respect to the distance between the hosel bore opening 258 and the hosel base 262 (hereinafter referred to as the "hosel length"). The hosel length can be measured parallel to the hosel bore axis 268. In many embodiments, the tube insert length can be between 70% and 90% of the hosel length. In some embodiments, the tube insert length can be between 70% and 75%, between 75% and 80%, between 80% and 85%, or between 85% and 90% of the hosel length. The tube insert length is important in relation to the hosel length. If the tube insert length is too short, discretionary mass is not maximized. However, if the tube insert length is too long, the tube insert top end 231 may be too close to the hosel bore opening 258, and the tube insert 230 may be subjected to too high stresses upon impact.

[0104] To avoid compromising the structural integrity of the club head 100, the tube insert 230 can be spaced from high stress areas located near the hosel bore opening 258. The tube insert upper end 231 can be offset from the top edge of the hosel bore opening 258 by a tube insert offset distance 234. The tube insert offset distance 234 can be measured parallel to the hosel bore axis 268. In many embodiments, the tube insert offset distance 234 can be within a range of 0.150 inches to 0.350 inches. In some embodiments, the tube insert offset distance 234 can be between 0.150 and 0.200 inches, between 0.200 and 0.250 inches, between 0.250 and 0.300 inches, or between 0.300 and 0.350 inches. In some embodiments, the tube insert offset distance 234 can be 0.150 inches, 0.160 inches, 0.170 inches, 0.180 inches, 0.190 inches, 0.200 inches, 0.210 inches, 0.220 inches, 0.230 inches, 0.240 inches, 0.250 inches, 0.260 inches, 0.270 inches, 0.280 inches, 0.290 inches, 0.300 inches, 0.310 inches, 0.320 inches, 0.330 inches, 0.340 inches, or 0.350 inches.

[0105] As discussed above with reference to Figures 17A and 17B, the stresses from the impact of a ball on the striking face 202 of the golf club head 200 are highest in the impact area near the striking face geometric center 220. As the distance from the impact point increases, the stress experienced by the club head material decreases. Figures 17A and 17B illustrate that as the stresses propagate through the material, they propagate primarily through the exterior surface of the golf club head 200, decreasing at the interior cavity 207 of the golf club head 200 and toward the rear 211 of the golf club head 200. The tube insert top end 231 is located away from the stress propagation. Similarly, the attachment point of the shaft sleeve 266 to the threaded fastener 276 of the hosel base 262 is also located away from the stress propagation. Thus, the contact point between the shaft sleeve 266 and the golf club head 200 is in an area of ​​lower stress. The tube insert 230 is located within the interior cavity 207 and is spaced from the exterior surface of the club head 200 to protect it from high stresses during impact.

[0106] In the embodiment shown in FIGS. 7-9, the hosel wall 254 is thinned relative to the upper hosel wall 280. As such, a lip 278 is formed at the junction of the upper hosel wall 180 and the remainder of the hosel wall 254. The lip 278 can be formed at a lower end of the upper hosel wall 280. The lip 278 is formed by an abrupt change in thickness between the upper hosel wall 280 and the thinned hosel wall 254. In many embodiments, the upper hosel wall 280 has a thickness (measured from the outer surface of the upper hosel wall 280 to the inner surface of the upper hosel wall 280) that is greater than the thickness of the remainder of the hosel wall 254 (measured from the outer surface of the upper hosel wall 254 to the inner surface of the upper hosel wall 254). The upper end 231 of the tube insert 230 can be configured to abut the lip 278 formed by the upper hosel wall 280 and the hosel wall 254. Thus, the tube insert 230 extends downwardly from the lip 278 into the internal cavity 207 and all the way to the hosel base 262 .

[0107] While the hosel bore opening 258 is defined by the hosel 252 itself, the majority of the hosel bore 256 is defined by the inner surface of the tube insert 230. In many embodiments, the hosel wall upper portion 280 forms the hosel bore opening 258 and the upper portion of the hosel bore 256 (i.e., the portion of the hosel bore 256 proximate the hosel bore opening 258), and the tube insert 230 forms the remaining portion of the hosel bore 256. The tube insert 230 completely separates the hosel bore 256 from the remainder of the internal cavity 207. The tube insert 230 is sealed at both the upper and lower ends 231, 232 by the lip 278 and the hosel base 262, respectively. The tube insert 230 completely seals the hosel bore 256 from the internal cavity 207 such that, even when the shaft sleeve 266 is removed, debris and other particulates cannot enter the internal cavity 207 through the hosel bore opening 258. The seal created by the tube insert 230 also prevents water from entering the internal cavity 207 through the hosel bore opening 258. This can be especially important to keep the interior surface of the club head 200 from rusting.

[0108] As discussed above, the tube insert 230 is formed of a lightweight material having a density less than that of the body material. Replacing the tube portion and a portion of the hosel wall 254 with the lightweight tube insert 230 reduces the mass of the shaft receiving structure 250 compared to a similar structure formed entirely from the body material. Having the lightweight tube insert 230 provides a structure for retaining the shaft and shaft sleeve 266 within the hosel bore 256, sealing the hosel bore 256 from the internal cavity 207, and creates discretionary mass that can be redistributed to advantageous locations to improve the mass properties of the club head 200.

[0109] As described above, the lower end 232 of the tube insert 230 connects to the hosel base 262 and forms a seal. In the illustrated embodiment of FIGS. 7-9 , the hosel base 262 is formed by a lightweight, removable end cap 240. The end cap 240 may be formed as a separate component from both the club head body 201 and the tube insert 230. When fully assembled, the end cap 240 may cover the lower end 232 of the tube insert 230, close the lower opening 274, and enclose and hold the tube insert 230 in place within the interior cavity 207.

[0110] The end cap 240 may be constructed of a lightweight material (the aforementioned lightweight materials and associated densities defined above may apply to the end cap 240). In some embodiments, the material of the end cap 240 may be the same as the material of the tube insert 230. In other embodiments, the end cap 240 and the tube insert 230 may be formed of different lightweight materials.

[0111] In some embodiments, as illustrated in FIG. 9, the end cap 240 can have one or more alignment features configured to receive and center the tube insert 230 relative to the end cap 240 and secure the tube insert 230 in place. In some embodiments, as illustrated in FIG. 9, the end cap 240 can form one or more notches 242 configured to receive the bottom end 232 of the tube insert 230. In some embodiments, as illustrated in FIG. 9, the end cap 240 can further include a protrusion 243 extending upwardly from the end cap body 241 into the hosel bore 256. The protrusion 243 can be shaped to be flush with the inner surface of the tube insert 230, aligning the end cap 240 with the hosel bore 256 formed in the tube insert 230. The end cap 240 can further include an opening 248 extending through the end cap body 241 from a lower surface of the end cap body 241 to an upper surface in the direction of the hosel bore 256. The openings 248 are configured to receive fasteners 276 that connect the shaft sleeve 266. In some embodiments, the openings 248 may or may not be threaded to accommodate the threaded fasteners 276.

[0112] By forming the hosel base 262 with a removable end cap 240, the tube insert 230 can be inserted into the internal cavity 207 through the lower opening 274 rather than having to be inserted through the hosel bore opening 258 from the top. With reference to FIGS. 7 and 8, the tube insert 230 can be inserted through the lower opening 274 so that the upper end 231 of the tube insert 230 abuts the lip 278 of the hosel 252. The tube insert 230 can be held in the internal cavity 207 by either mechanical or adhesive means. In some embodiments, the tube insert 230 is held in place by surrounding structure. As FIG. 7 shows, the tube insert upper end 231 is restrained from above by the lip 278, inwardly by the shaft sleeve 266, and outwardly by the hosel wall 254 below the lip 278. The lower end of the tube insert is constrained downwardly by hosel base 262 , outwardly by end cap 240 , and inwardly by bottom lap joint 238 .

[0113] In many other embodiments, the tube insert 230 can be held in place by adhesive means. In such embodiments, the shaft receiving structure 250 can form multiple lap joints near the bottom end 232 and top end 231 of the tube insert 230. FIG. 7 illustrates a bottom lap joint 238 formed by the club head body 201 between the bottom end 232 of the tube insert 230 and the hosel base 262, and a top lap joint 236 formed between the top end 231 of the tube insert 230 and the interior of the hosel 252 near the lip 278. The top lap joint 236 can be formed by the interior surface of the hosel wall 254 adjacent the lip 278. The bottom lap joint 238 can extend upward from the hosel base 262 (formed by the end cap 240) and into the interior cavity 207. The bottom lap joint 238 can be configured such that an inner surface of the bottom lap joint 238 accommodates the tube insert 230 and provides a surface for the tube insert 230 to adhere to. The tube insert 230 and the club head body 201 can be epoxied or otherwise bonded at both the top lap joint 236 and the bottom lap joint 238 such that the tube insert 230 remains secured in place even when the fasteners 276 are loosened and the shaft sleeve 266 is removed.

[0114] Inserting the tube insert 230 through the lower opening 274 simplifies the manufacturing and assembly process. Because there is no need to insert the tube insert 230 through the hosel bore opening 258, the hosel wall upper portion 280 and the hosel bore opening 258 can be formed integrally with the remainder of the hosel 252. Without the ability to insert the tube insert 230 through the lower opening 274, the hosel wall upper portion 280 and the hosel bore opening 258 would need to be formed separately from and connected to the remainder of the hosel 252 to surround the upper end 231 of the tube insert 230. Thus, the shaft receiving structure 250 capable of receiving the tube insert 230 through the lower opening 274 allows the shape of the hosel 252, including the receiving shape configured to receive the shaft sleeve 266, to be cast integrally as one piece.

[0115] As discussed above, the inclusion of lightweight components to replace portions of the shaft receiving structure reduces the mass of the shaft receiving structure. In some embodiments, the lightweight shaft receiving structure produces discretionary mass of 3 grams to 12 grams. The discretionary mass produced by the lightweight shaft receiving structure can be distributed throughout the club head to improve mass properties and performance.

[0116] (IV. Lightweight Shaft Support Structure with Lightweight Collar) 10-12 show a second embodiment of a club head 300 including a hosel tube and a lightweight shaft receiving structure 350 in which a portion of the hosel wall 354 (specifically the upper portion of the hosel wall) is replaced with a lightweight material. The shaft receiving structure 350 has a tube insert 330 similar to that of the first embodiment 200 that is insertable from the top rather than the bottom opening 374. Rather than a one-piece hosel in which the entire hosel wall (including the upper portion of the hosel wall) is integrally formed as part of the club head body 301, the second embodiment of the shaft receiving structure 350 has a lightweight collar 386 formed separately from the remainder of the hosel 352 in place of the upper portion of the hosel wall. The collar 386 can be connected to the hosel wall 354 to create a two-piece hosel 352. The collar 386 can be connected to the upper portion of the hosel wall 354 such that the collar 386 forms the upper portion of the two-piece hosel 352.

[0117] The collar 386 is configured to interact with the shaft sleeve 366. The collar 386 forms the hosel bore opening 358. In many embodiments, the collar can form a receiving shape configured to receive the shaft sleeve 366. For example, in some embodiments, the hosel collar 386 can form one or more lobes configured to receive one or more surface features of the shaft sleeve 366 and provide adjustability for the loft angle and / or lie angle of the club head. Thus, the collar 386 is configured to receive and hold the shaft sleeve 366 in place. As shown in FIG. 10, the collar 386 forms a lip 378 that acts as a lap joint 336 to connect and / or secure the tube insert 330 within the internal cavity 307. The lip 378 can be located immediately below the collar 386. When inserted, the top end 331 of the tube insert 330 abuts the lip 378. The tube insert 330 may be inserted from the top of the club head 300 through a hosel wall opening 359 formed by an upper edge 355 of the hosel wall 354 and then covered by a collar 386 .

[0118] The hosel wall 354 and the collar 386 can be connected at a joint formed between an upper edge 355 of the hosel wall 354 and a lower edge 388 of the collar 386. In many embodiments, the hosel wall 354 and the collar 386 include a mating shape configured to facilitate connecting the collar 386 to the hosel wall 354 by mechanical interlocking and / or adhesive. In some embodiments, as shown by FIG. 12 , the hosel wall 354 defines a number of teeth 391 extending upwardly from the hosel wall upper edge 355. The collar 386 can include a number of recesses 390 formed in the collar lower edge 388 that correspond and fit with the shape of the number of teeth 391. The number of teeth 391 can be configured to fit within the number of recesses 390 to connect the collar 386 to the hosel wall 354. The collar 386 can be secured in place using epoxy or additional mechanical fasteners.

[0119] In some embodiments, the collar 386 has a lightweight material as defined above. In many embodiments, the collar 386 is formed of a lightweight metal material having a density less than that of the metal body 301. In many embodiments, the collar 386 is provided by a lightweight metal because the collar 386 is located at the upper end of the hosel 352, which is typically subject to higher stresses than other portions of the shaft receiving structure 350. For example, in some embodiments, the collar 386 can be formed of aluminum, an aluminum alloy, titanium, a titanium alloy, magnesium, or a magnesium alloy. In many embodiments, the collar 386 is formed of a metal material similar to that of the shaft sleeve 366. Having both the collar 386 and the shaft sleeve 366 be similar metals prevents wear between any receiving features of the respective components.

[0120] The shaft receiving structure 350 with collar 386 further includes a lightweight tube insert 330 that is the same or substantially the same as the tube insert 230 described above in connection with the club head 200. The upper end 331 of the tube insert 330 abuts the lip 378 formed by the collar 386 and extends downwardly toward the hosel base 362 and lower opening 374. As with the first embodiment, the tube insert 330 forms a majority of the hosel bore 356 and seals the hosel bore 356 from the remainder of the interior cavity 307.

[0121] In addition to replacing the mass of the hosel tube with the lightweight tube insert 330, the mass of the shaft receiving structure 350 is further reduced by replacing the body material of the upper hosel wall with a lightweight collar 386. The replacement of mass via the lightweight tube insert 330 and collar 386 creates discretionary mass that is redistributed throughout the club head 300. In some embodiments, the lightweight shaft receiving structure 350, including the tube insert 330 and collar 386, can create discretionary mass of 3 to 12 grams.

[0122] Similar to the tube insert 230 described above, the tube insert upper end 331 of the tube insert 330 can be offset from the top end of the hosel bore opening 358 by a tube insert offset distance 334. The tube insert offset distance 334 can be measured parallel to the hosel bore axis 368. In many embodiments, the tube insert offset distance 334 can be within a range of 0.150 inches to 0.350 inches. In some embodiments, the tube insert offset distance 334 can be between 0.150 and 0.200 inches, between 0.200 and 0.250 inches, between 0.250 and 0.300 inches, or between 0.300 and 0.350 inches. In some embodiments, the tube insert offset distance 334 can be 0.150 inches, 0.160 inches, 0.170 inches, 0.180 inches, 0.190 inches, 0.200 inches, 0.210 inches, 0.220 inches, 0.230 inches, 0.240 inches, 0.250 inches, 0.260 inches, 0.270 inches, 0.280 inches, 0.290 inches, 0.300 inches, 0.310 inches, 0.320 inches, 0.330 inches, 0.340 inches, or 0.350 inches.

[0123] As discussed above with reference to Figures 17A and 17B, the stresses from the impact of a ball on the striking face 302 of the golf club head 300 are highest in the impact area close to the striking face geometric center 320. As the distance from the impact point increases, the stress experienced by the club head material decreases. Figures 17A and 17B illustrate that as the stresses propagate through the material, they propagate primarily through the exterior surface of the golf club head 300, decreasing at the interior cavity 307 of the golf club head 300 and decreasing toward the rear 311 of the golf club head 300. The tube insert top end 331 is located away from the stress propagation. Similarly, the attachment point of the shaft sleeve 366 to the threaded fastener 376 of the hosel base 362 is also located away from the stress propagation. Thus, the contact point between the shaft sleeve 366 and the golf club head 300 is in an area of ​​lower stress. Tube insert 330 is located within interior cavity 307 and is spaced from the exterior surface of club head 300 to protect it from high stresses during impact.

[0124] In many embodiments, such as the embodiment shown in FIGS. 10-12, rather than forming a separate end cap, the hosel base 362 of the second embodiment can be integral with the club head body 301. The hosel base 362 can be cast as part of the body 301 proximate the lower opening 374. The hosel base 362 extends across the lower opening 374 and separates the exterior of the club head 300 from the interior cavity 307 proximate the sole 312. Similar to the end cap 240 of the first embodiment, the hosel base 362 forms a platform configured to receive the lower end 332 of the tube insert 330 and hold the tube insert 330 in place. In some embodiments, the hosel base 362 can include one or more alignment features configured to center the tube insert 330 relative to the hosel base 362. In some embodiments, as shown in FIG. 10, the hosel base 362 can include a protrusion 343 extending upwardly from the hosel base 362 into the hosel bore 356. The protrusion 343 can be flush with the inner surface of the tube insert 330 to align the tube insert 330 with the hosel base 362. As shown in FIG. 11, the hosel base 362 further includes an opening 348 extending into the hosel bore 356. The opening 348 is configured to receive a fastener 376 that secures the shaft sleeve 366 within the hosel bore 356. In some embodiments, the opening 348 can be threaded to accommodate the threaded fastener 376. The hosel base 362 seals the lower opening 374 to hold the tube insert 330 in place within the internal cavity 307. In another embodiment (not shown), the club head 300 including the shaft-receiving structure 350 having the collar 386 may be combined with an end cap similar to the end cap 240 of the club head 200 .

[0125] The tube insert 330 may be held within the internal cavity 307 by mechanical and / or adhesive means. In some embodiments, the tube insert 330 is held in place by surrounding structure. As shown in Figures 10 and 11, the tube insert upper end 331 is restrained from above by lip 378, inwardly by shaft sleeve 366, and outwardly by hosel wall 354 below lip 378. The tube insert lower end is restrained from below by hosel base 362 and inwardly by protrusion 343.

[0126] In many embodiments, the tube insert 330 can be held in place by adhesive means. In such embodiments, the shaft receiving structure 350 can form multiple lap joints near the bottom end 332 and the top end 331 of the tube insert 330. FIG. 10 illustrates a bottom lap joint 338 formed by the hosel base 362 and a top lap joint 336 formed in combination by at least a portion of the hosel wall 354 and at least a portion of the collar 386. The tube insert 330 and club head 300 can be epoxy bonded together at both the top and bottom lap joints such that the hosel insert remains fixed in place even when the fasteners are loosened and the shaft sleeve is removed.

[0127] As discussed above, by providing a separate collar 386 on the hosel 352 to replace the upper portion of the hosel wall, the collar 386 can be formed from a lighter material than the hosel 352, further reducing the mass of the shaft receiving structure 350. The inclusion of the lightweight tube insert 330 and lightweight collar 386 reduces the mass of the shaft receiving structure 350 compared to prior art shaft receiving structures formed from the body material. In some embodiments, the inclusion of the lightweight tube insert 330 and collar 386 in place of a denser material reduces the mass of the shaft receiving structure 350 by 3 to 12 grams. The reduced mass of the shaft receiving structure 350 provides discretionary mass that can be distributed throughout the club head 300 to improve mass properties and performance.

[0128] (V. Lightweight shaft support structure with hosel insert) 13 and 14 show a golf club head 400 with another embodiment of a lightweight shaft receiving structure 450. The lightweight shaft receiving structure 450 includes a hosel tube and a lightweight hosel insert 430 that forms the entirety of a hosel wall 454. The shaft receiving structure 450 has a hosel insert 430 of a lightweight material (as defined above). As shown in FIG. 13, the body 401 forms a hosel transition section 464 that connects the crown 410 to the hosel wall 454, but does not form the hosel wall 454 beyond the hosel transition section 464. Instead, the body 401 forms a hosel transition opening 465 at the upper end of the hosel transition section 464. The hosel insert 430 can be inserted into the hosel transition opening 465 and connected to the hosel transition section 464. The hosel insert 430 is located outside the internal cavity 407 and forms a wall portion 435 that is visible from the outside of the club head 400, and an internal tube portion 437 that extends into the internal cavity 407 and seals the hosel bore 456 from the remainder of the internal cavity 407. The wall portion 435 extends upwardly from the hosel transition portion 464. Thus, the inner surface of the wall portion 435 defines the upper portion of the hosel bore 456. The wall portion 435 forms the entirety of the hosel wall, including the hosel bore opening 458. Thus, the wall portion 435 is configured to receive the shaft sleeve 466 through the hosel bore opening 458. Additionally, the wall portion 435 can form any receiving shape configured to receive the shaft sleeve 466. Such a shape can be formed on the inner surface of the wall portion 435.

[0129] Hosel insert 430 further includes a tube portion 437 that extends downwardly from the bottom of wall portion 435 through hosel transition opening 465 toward hosel base 462. The inner surface of tube portion 437 forms the lower portion of hosel bore 456. Tube portion 437 seals hosel bore 456 and the exterior of club head 400 from internal cavity 407, preventing debris, particles, and water from entering internal cavity 407 through the openings in hosel bore 456.

[0130] The hosel insert 430 is a generally tubular hollow member that defines an outer diameter and an inner diameter defined by an outer surface and an inner surface, respectively. The outer diameter of the hosel insert 430 may vary along different portions of the hosel insert 430. As shown in FIG. 13, the outer diameter of the wall portion 435 is substantially larger than the outer diameter of the tube portion 437. The diameter of the hosel insert 430 changes abruptly at the hosel transition opening 465, clearly defining where the wall portion 435 ends and the tube portion 437 begins. The abrupt change in diameter forms a ledge 478 that separates the wall portion 435 and the tube portion 437. The ledge 478 abuts the upper edge of the hosel transition portion 464. The outer diameter of the wall portion 435 at the hosel transition opening 465 may match the diameter of the hosel transition opening 465 at the upper edge. In this manner, the hosel transition portion 464 and the wall portion 435 form a smooth continuous surface therebetween, resembling a unitary, integrally formed hosel. The outer diameter of tube portion 437, which is smaller in diameter than hosel transition portion 464, is sized to extend through hosel transition opening 465 into the internal cavity. The relatively large outer diameter of wall portion 435 and the relatively small outer diameter of tube portion 437 allow hosel insert 430 to replace as much mass as possible with lightweight material. Internally, hosel insert 430 replaces the mass of the hosel tube, and externally, hosel insert 430 replaces hosel wall 454 with lightweight material to create discretionary mass.

[0131] In some embodiments, the hosel transition portion 464 can further include a joint wall 461 within the internal cavity 407 and configured to center the tube portion 437 and provide a surface for the hosel insert 430 to interface with. The joint wall 461 can be a cylindrical wall integrally formed with the hosel transition portion 464. The joint wall 461 extends at least partially from the hosel transition opening 465 toward the hosel base 462. The joint wall 461 has an inner diameter that corresponds to an outer diameter of the tube portion 437. The tube portion 437 of the hosel insert 430 fits flush against the joint wall 461. The joint wall 461 thus functions as a lap joint that can secure and center the hosel insert 430 within the internal cavity 407.

[0132] The club head 400 of the third embodiment further forms a hosel base 462 that forms a floor for the hosel insert 430, and the lower end of the hosel tube portion 437 is configured to abut the hosel base 462. The lower end of the hosel insert 430 (i.e., the lower end of the hosel tube portion 437) can be supported on the hosel base 462. The hosel base 462 of the third embodiment can be substantially similar to the integrally molded hosel base 462 of the second embodiment. The hosel base 462 can be integrally cast with the club head body 401 and close a lower opening 474 to separate the exterior of the club head from the interior cavity 407 adjacent the sole. As shown in FIG. 14, the hosel base 462 can have an opening 448 to provide a passage for a fastener 476 to connect to the shaft sleeve 466 in the hosel bore 456. In some embodiments, the hosel base 462 can have one or more alignment features configured to center the hosel insert 430 relative to the hosel base 462. In some embodiments (not shown), a club head 400 having a shaft-receiving structure 450 with a hosel insert 430 can be combined with an end cap similar to end cap 240 of club head 200.

[0133] The hosel insert 430 can be retained in the shaft receiving structure 450 by mechanical and / or adhesive means. In many embodiments, the hosel insert 430 is held in place by a binding force generated by the fastener 476, the shaft sleeve 466, and the hosel base 462. As shown in FIG. 14, the fastener 476 extends through the lower opening 474 and connects to the lower end of the shaft sleeve 466. As the shaft sleeve 466 is inserted through the hosel bore opening 458 and the fastener 476 is inserted through the opening 448 of the hosel base 462, the fastener 476 and the shaft sleeve 466 hold the hosel insert 430 in compression and generate opposing forces. Specifically, the fastener 476 presses the shaft sleeve 466 downward against the hosel insert 430, which in turn pushes the hosel base 462 downward. The binding force created between the fastener 476 and the shaft sleeve 466 holds the hosel insert 430 in place within the internal cavity 407 .

[0134] In many other embodiments, the hosel insert 430 can be held in place by adhesive means. In such embodiments, the shaft receiving structure 450 can form a number of lap joints configured to connect the hosel insert 430 to the club head body 401 through the use of an adhesive or epoxy. FIG. 13 shows the lap joint 436 formed between the tube portion 437 and the mating wall 461. The hosel insert 430 and the club head 400 can be bonded with an epoxy or other adhesive at the lap joint 436 such that the hosel insert 430 remains secured in place even when the fasteners 476 are loosened and the shaft sleeve 466 is removed.

[0135] The inclusion of the lightweight hosel insert 430 reduces the mass of the shaft receiving structure 450 as compared to a similar structure formed solely from body material. In some embodiments, the inclusion of the lightweight hosel insert 430 instead of a denser material reduces the mass of the shaft receiving structure 450 by 3 to 12 grams. The reduced mass of the shaft receiving structure 450 ensures discretionary mass that can be distributed throughout the club head 400 to improve mass properties and performance.

[0136] The hosel insert 430 forms an outer portion of the hosel 452. Because the hosel insert 430 extends to the hosel bore opening 458, it may be subject to greater stresses during impact than the hosel tube inserts 230, 330 of previous embodiments, and therefore it may be advantageous to provide the hosel insert 430 from a material having greater strength than a composite material. In many embodiments, the hosel insert 430 may be constructed from a lightweight metallic material rather than a non-metallic material. In some embodiments, the hosel insert 430 may be formed from aluminum, an aluminum alloy, or any lightweight metallic material that has a lower density than the body material. By providing the hosel insert 430 from a lightweight metal, the mass of the shaft receiving structure 450 may be reduced (as the lightweight metal has a lower density than the body material) while still maintaining the structural integrity of the club head 400.

[0137] (VI. Tubeless lightweight shaft support structure) FIG. 15 illustrates another embodiment of a lightweight shaft receiving structure 550 without a tube insert (hereinafter referred to as a “tubeless” shaft receiving structure 550). In the embodiment illustrated in FIG. 15, the hosel tube of the prior art design is completely eliminated. As such, the shaft sleeve 566 is not hidden within a tube section or tube insert. As such, at least a portion of the shaft sleeve 566 is exposed to the internal cavity 507. In many embodiments, at least a portion of the shaft sleeve outer wall 567 is exposed to the internal cavity 507. The tubeless shaft receiving structure 550 is formed entirely from the body material and can have a mass reduced by 3 to 12 grams compared to a similar shaft receiving structure with a hosel tube. The tubeless shaft receiving structure 550 can further include one or more components that can form other portions of the club head 500 that would have been formed from the body material in the prior art, such as the hosel base 562. Reducing the mass of the shaft-receiving structure 550 by eliminating the hosel tube and forming other components from lightweight materials rather than body material allows discretionary mass to be redistributed to other areas of the club head 500 to improve mass properties and performance.

[0138] The tubeless shaft receiving structure 550 may be substantially similar to the shaft receiving structure 250 illustrated in (FIGS. 7-9), except that the tubeless shaft receiving structure 550 lacks a tube insert (such as the tube inserts 230, 330 of the previous embodiments). The tubeless shaft receiving structure 550 includes a hosel 552 and a shaft sleeve 566. The hosel 552 defines a hosel wall 554 and a hosel wall upper portion 580 defines a hosel bore opening 558 configured to receive the shaft sleeve 566.

[0139] The shaft receiving structure 550 further includes an end cap 540 that forms a hosel base 562. The end cap 540 may be formed as a separate piece from the club head body 101. The end cap 540 is provided to form the hosel base 562 from a lightweight material, rather than forming the hosel base from the body material, as is common in the prior art. In many embodiments, the end cap 540 may be substantially similar to the end cap 240. The end cap 540 may be configured to close the lower opening 574.

[0140] 15, the shaft receiving structure 550 further includes a base wall 561 extending from the lower opening 574 into the interior cavity 507. The bottom of the hosel base wall 561 may define a ledge 578, and the end cap 540 is configured to abut the ledge 578. The end cap 540 may be shaped to cover the entire lower opening 574 and separate the exterior of the club head 500 from the interior cavity 507.

[0141] Because there is no tube insert or hosel tube, the tubeless shaft receiving structure 550 does not have a continuous hosel bore. In other words, the tubeless shaft receiving structure 550 does not have a hosel bore that extends from the hosel bore opening 558 to the hosel base 562. As shown in FIG. 15 , the shaft receiving structure 550 includes an upper hosel bore 556a and a lower hosel bore 556b that is separate from the upper hosel bore 556a. The upper hosel bore 556a can be defined by an inner surface of the upper hosel wall 580. In many embodiments, the upper hosel bore 556a can extend from the hosel bore opening 558, which is defined by an upper edge of the upper hosel wall 580, to the bottom of the upper hosel wall 580. In other embodiments, a portion of the upper hosel bore 556a can be defined by the hosel wall 554. The upper hosel bore 556a can transition abruptly or gradually into the internal cavity 507. The upper hosel bore 556a transitions into the internal cavity 507 as the hosel wall 554 diverges from the shaft sleeve 566. The lower hosel bore 556b can be formed by the inner surface of the hosel base wall 561. The lower hosel bore 556b extends from the lower opening 574 to the top of the hosel base wall 561. Like the upper hosel bore 556a, the lower hosel bore 556b leads directly into the internal cavity 507.

[0142] There is no structure connecting the upper hosel bore 556a and the lower hosel bore 556b. The upper hosel bore 556a and the lower hosel bore 556b each communicate independently with the internal cavity 507. The upper hosel bore 556a and the lower hosel bore 556b do not communicate with each other. The shaft sleeve 566 extends through a gap 557 formed between the upper hosel bore 556a and the lower hosel bore 556b, thereby exposing the shaft sleeve 566 to the internal cavity 507.

[0143] The tubeless shaft receiving structure 550 can be held together by a fastener 576, a shaft sleeve 566, and an end cap 540. The shaft sleeve 566 is configured to be inserted into the upper hosel bore 556a through a hosel bore opening 558 and abut against the hosel wall upper portion 580. The fastener 576 is configured to be inserted into the lower hosel bore 556b through an opening 548 formed in the end cap 540 and abut against the outer surface of the end cap 540. When the fastener 576 is tightened, it presses against the outer surface of the end cap 540 and applies a binding force to the shaft sleeve 566. When the fastener 576 and the shaft sleeve 566 are securely connected, they create a binding force that holds the components of the shaft receiving structure 550 together. The fastener 576 creates an upward force that presses against the end cap 540, and the shaft sleeve 566 creates an opposing downward force against the inner surface of the hosel wall upper portion 580. In this manner, shaft sleeve 566 is retained within upper hosel bore 556a by the downward pulling force on shaft sleeve 566. The binding force created between fastener 576 and shaft sleeve 566 holds the components of shaft receiving structure 550 in place.

[0144] The tubeless shaft receiving structure 550 provides the maximum amount of discretionary mass to be redistributed to the club head 500. The tubeless shaft receiving structure 550 has minimal structure because the hosel tube is completely removed. Additionally, the tubeless shaft receiving structure 550 does not reintroduce any mass, even if negligible, by including a separate tube insert. The tubeless shaft receiving structure 550 can be advantageous for inclusion in a club head 500 where maximum discretionary mass is desired over the ability to seal the interior cavity 507.

[0145] (VII. Lightweight Shaft Receiving Structure with External Hosel Insert) FIG. 16 illustrates another embodiment of a lightweight shaft receiving structure 650 that replaces a portion of the hosel wall 654 and forms a portion of the hosel transition 664 with a hosel insert 630 constructed of a lightweight material (as defined above). In many embodiments, the hosel wall 654 and the hosel transition 664 can be formed together as one insert 630 configured to connect to the club head body 601 at the crown 610. In such an embodiment, the club head 600 can form a hosel transition opening 665 near the heel side of the crown 610. The hosel insert 630 can be configured to connect to the club head body 601 at the periphery of the hosel transition opening 665. In many embodiments, the hosel insert 630 can be attached to the club head body 601 at the hosel transition opening 665 by mechanical and / or adhesive means. In some embodiments, the hosel insert 630 can have a mating feature at the hosel transition 664 that is configured to connect to a corresponding mating feature formed at the periphery of the hosel transition opening 665. The hosel insert 630 can have any receiving shape configured to form the hosel bore opening 658 and connect the shaft sleeve 666 within the hosel bore 656. For example, in some embodiments, the hosel insert 630 can form one or more lobes configured to receive one or more surface features of the shaft sleeve 666 and provide adjustability for the loft angle and / or lie angle of the club head.

[0146] The hosel insert 630 has an inner surface with an inner diameter that defines at least an upper portion of the hosel bore 656. In many embodiments, the inner surface of the hosel 652 defines a portion of the hosel bore 656 that extends from the hosel bore opening 658 to the hosel transition opening 665. In many embodiments, as shown by FIG. 16, the lightweight hosel insert 630 is disposed only externally and does not extend through the hosel transition opening 665 or into any portion of the internal cavity 607. The interior portions of the shaft receiving structure 650 (i.e., the tube portion 660, the hosel base 662, etc.) can be cast integrally with the remainder of the club head body 601. Thus, the tube portion 660, which is separate from the lightweight hosel insert 630, forms the lower portion of the hosel bore 656 that extends from the hosel transition opening 665 to the hosel base 662. Because the tube portion 660 and hosel base are formed from high strength body material, the shaft-receiving structure 650 is able to accommodate any stresses that may occur adjacent the sole 612 .

[0147] In some embodiments, the lightweight hosel and hosel transition 664 can be formed as a separate insert and integrally formed with a portion of the club head body 601, rather than being attached to the crown via mechanical or adhesive means. This configuration is applicable to club heads having a multi-material construction with a lightweight non-metallic component forming a majority of the crown 610, such as a crown insert made from a composite material. The lightweight hosel insert 630 and hosel transition 664 can function as an extension of the crown 610, extending upwardly from the crown 610 at the heel end to form the hosel transition 664 and hosel wall 654. In such embodiments, the material of the hosel wall 654 and hosel transition 664 can be the same as the material of the composite crown 610, since the hosel wall 654 and hosel transition 664 are integrally formed with the composite crown 610. The integral hosel wall 654 and hosel transition 664 can be formed in combination with any of the variations of composite crowns described in detail above, such as the composite crown 610 that wraps around the skirt 614 to form part of the sole 612 at the heel 604 and / or toe 606.

[0148] Replacing the hosel wall 654 and hosel transition section 664 with a lightweight material reduces the mass of the shaft receiving structure 650 compared to a similar structure formed entirely of the body material, whether formed integrally with the composite crown 610 of the multi-material club head or as a separate insert connected at the hosel transition opening 665. In some embodiments, the inclusion of the hosel insert 630 reduces the mass of the shaft receiving structure 650 by 3 grams to 12 grams by replacing the hosel wall 654 and forming the hosel transition section 664 with a lightweight material. The reduction in mass of the shaft receiving structure 650 ensures mass properties and discretionary mass that can be distributed throughout the club head 600 to improve performance.

[0149] (example) (Example 1: Stress distribution in a golf club head with a lightweight shaft support structure) As discussed above, the prior art shaft receiving structures surprisingly have portions that do not contribute significantly to the structural integrity of the golf club head, such as the hosel tube 160. After analysis was performed showing such low stresses on the hosel tube 160, experiments were performed to determine whether the hosel tube could simply be removed or replaced with a lighter material to provide discretionary mass.

[0150] 17A and 17B illustrate peak stresses during impact of a golf club head with a golf ball. FIG. 17A illustrates the peak stresses of a prior art golf club head 100 having a hosel tube 160 with the same material as the club head body 101. The finite element analysis shown in FIG. 17A shows that the hosel tube 160 experiences negligible stresses during impact. Negligible stresses are defined as stresses that are less than 50% of the material failure load. This means that the hosel tube 160 does not experience significant structural loads. It was unexpected that the hosel tube 160 would have such low stresses during impact and not contribute significantly to the structural integrity of the club head 100.

[0151] To expand on the analysis illustrated in Figure 17A, an otherwise identical club head 100 was modeled with the hosel tube 160 removed. Figure 17B illustrates the peak stresses of the golf club head 100 without the hosel tube 160, exposing the shaft sleeve 166 to the interior cavity 107. Analysis of the golf club head without the hosel tube 160 showed that the modified shaft support structure still experienced very low levels of stress at impact.

[0152] At peak stresses during impact, the striking face 102 adjacent the leading edge 103, the crown return portion 122, and the sole 112 absorb the impact forces and are highly stressed. These areas require high strength body materials to avoid damage from impact. In contrast, the hosel tube 160 illustrated in FIG. 17A is subjected to very little impact force during ball impact. As discussed above, this allows the hosel tube to be removed entirely or replaced with a material that is less dense and has lower material strength. As shown in FIG. 17B, the hosel tube 160 can be removed and the exposed shaft sleeve 166 is subjected to very little stress from impact. This indicates that the hosel tube 160 is not necessary for the durability of the golf club head when impacting a golf ball.

[0153] The portion of the golf club head 100 adjacent the hosel 152 and within the internal cavity 107 of the club head 100 is subject to lower stresses during impact as compared to the striking face 102, crown return 122, and sole 112 adjacent the leading edge 103 of the golf club head 100. Other areas of lower stress are located further away from the striking face 102. The lower stress portions of the club head 100 adjacent the hosel 152 and within the internal cavity 107 of the golf club head can be replaced without compromising the durability of the club head during impact. As discussed above, the majority of the impact forces experienced by the shaft receiving structure 150 occur adjacent the upper and lower contact surfaces 186 and 187 (shown in FIGS. 18A and 18B). The further away from the upper and lower contact surfaces 186 and 187, the less stress the shaft receiving structure 150 is subject to and the less mass required to structurally support the club head 100. Mass can be reduced from portions of the shaft receiving structure 150 that are remote from the upper contact surface 186 and the lower contact surface 187. In many embodiments, mass can be reduced from portions of the shaft receiving structure that are characterized by a distance away from the hosel bore opening 158, which will be described below in connection with the tube insert offset distance.

[0154] The analysis shown in Figures 17A and 17B indicates that from a durability standpoint, the hosel tube 160 can be made of any lightweight material or can be eliminated entirely. To maximize discretionary mass, it may be desirable to provide a hosel tube made of the lightest material possible or to eliminate it entirely, depending on the desired functionality. For example, in some embodiments, it may be desirable to maintain a lightweight hosel tube in the form of a tube insert (tube insert 230, 330, etc.) for purposes other than load-bearing, such as sealing the interior cavity 107 from the hosel bore 156 or holding the shaft sleeve 166 in place. In other embodiments, functions other than load-bearing of the hosel tube 160 may not be desired, and the hosel tube 160 may be eliminated entirely. Such is the case for the shaft receiving structure 550 detailed above. Examples of such club heads are described below.

[0155] (Example 2: Mass characteristics of a club head with a lightweight shaft support structure) Mass properties were compared between a number of exemplary club heads including the lightweight shaft receiving structure and a control club head. The MOI values ​​of each club head were compared. Additionally, the amount of discretionary mass resulting from the inclusion of the lightweight shaft receiving structure in each of the exemplary club heads was compared relative to the control club head. Each club head was similarly constructed except for the difference in the shaft receiving structure.

[0156] The first exemplary club head was a fairway wood type club head with a lightweight shaft receiving structure similar to shaft receiving structure 250. The first exemplary club head had a lightweight tube insert forming a hosel tube and a lightweight lower end cap forming a hosel base. The tube insert was inserted into the interior cavity through a lower opening. The end cap covered the lower opening and enclosed the tube insert within the interior cavity.

[0157] The second exemplary club head was a fairway wood type club head with a lightweight shaft receiving structure similar to shaft receiving structure 550. The second exemplary club head had a tubeless design. There was no tube insert in the second exemplary embodiment. The club head had an upper hosel bore formed by the inner surface of the upper part of the hosel wall and a lower hosel bore formed by the inner surface of the hosel base wall. The upper and lower hosel bores were not connected and both opened into the interior cavity. Thus, when the shaft sleeve was inserted, the outer wall of the shaft sleeve was exposed to the interior cavity. The second exemplary club head had a lightweight end cap that formed the hosel base and covered the lower opening.

[0158] The control club head was a prior art fairway wood type club head having a prior art shaft receiving structure similar to shaft receiving structure 150. The control club head included a hosel, hosel tube, and hosel base, each of which was integrally formed with the club head body and formed from the body material. The control club head shaft receiving structure did not have any lightweight components.

[0159] Table 1 below lists the CG location for each of the example club heads and the control club head. The discretionary mass values ​​represent how much mass is saved by providing each example club head with a lightweight shaft receiving structure compared to the control club head. [Table 1]

[0160] As is evident from Table 1, the exemplary club head exhibits an increase in discretionary mass, where the discretionary mass was reallocated about the club head to improve mass properties. Specifically, in this example, the discretionary mass was reallocated to improve CG location, favoring a lower CG location to provide higher launch, less spin, and faster ball speed. The discretionary mass was reintroduced to the club head by adding mass to the mass pad on the sole. In other words, in the exemplary club head, a portion of the mass pad on the sole was thickened to create a lower CG location. Thus, while both the control club head and the exemplary club head had the same overall mass, the exemplary club head had a more favorable mass distribution for CG placement purposes.

[0161] Exemplary club head 1 exhibited a 4.5 gram increase in discretionary mass over the control club head, resulting in a reduction in CG height (CGy) of 0.031 inches and an increase in CG depth (CGz) of 0.011 inches. The lower CG depth of the first exemplary club head may provide better performance such as higher launch, less spin, and faster ball speeds. The increased CG depth may aid in increasing and / or retaining the MOI.

[0162] Exemplary club head 2 exhibited a 5.5 gram increase in discretionary mass over the control club head, resulting in a reduction in CG height (CGy) of 0.036 inches and an increase in CG depth (CGz) of 0.015 inches. The lower CG depth of the second exemplary club head may provide better performance, such as higher launch, less spin, and faster ball speeds. The increased CG depth may help increase and / or maintain the MOI.

[0163] This comparison illustrates the benefit of providing a lightweight shaft receiving structure, which resulted in 4.5 grams to 5.5 grams of discretionary mass compared to the control club head, and an improvement in the CG location of the club head, which impacts performance characteristics. As discussed above, the creation of discretionary mass and the improvement in CG location come without sacrificing the structural integrity of the club head, as the lightweight components of the lightweight shaft receiving structures described herein are not critical to withstanding stress loads.

[0164] (Example 3: Ball flight performance of a club head with a lightweight shaft support structure) The ball flight performance of the exemplary club heads was compared to a control club head. Ball speed, launch angle, and spin rate for each club head were measured in field tests and compared.

[0165] The exemplary club heads were fairway wood type club heads with lightweight shaft receiving structures similar to shaft receiving structure 250. The first exemplary club head had a lightweight tube insert forming a hosel tube and a lightweight lower end cap forming a hosel base. The tube insert was inserted into the interior cavity through a lower opening. The end cap covered the lower opening and enclosed the tube insert within the interior cavity.

[0166] The control club head was a prior art fairway wood type club head with a prior art shaft receiving structure similar to shaft receiving structure 150. The control club head had a hosel, hosel tube, and hosel base, each integrally formed with the club head body and formed from the body material. The control club head shaft receiving structure did not have any lightweight components.

[0167] Table 2 below shows the results of the comparative tests. [Table 2]

[0168] As evident from Table 2, the exemplary club head exhibited an increased launch angle, a slight decrease in ball speed, and a substantially similar spin rate as compared to the control club head. The increased launch angle is a result of the lower CG location achieved by the discretionary mass created by the inclusion of a lightweight shaft receiving structure (as evident in Example 2). Although the exemplary club head exhibited a slight decrease in raw ball speed, the increased launch angle gives the exemplary club head the ability to diloft, returning ball speed to the exemplary club head and decreasing spin rate. The ability to diloft the exemplary club head provided by the increased launch angle provides an overall higher performance by resulting in a club head having equal or greater ball speed and less spin as compared to the control club head.

[0169] (Example 4: Durability of a club head with a lightweight shaft support structure) The exemplary club head of Example 3 was further tested for durability. Three samples of the exemplary club head were subjected to air cannon testing, in which a golf ball was fired at the club head face at a speed of 115 mph to simulate the high-speed impacts that occur during a golf swing between the club head and the ball. The first sample endured 3164 impacts, the second sample endured 3197 impacts, and the third sample endured 2413 impacts. Thus, each of the three samples had a similar durability to the prior art golf club head. The durability of the three samples experiencing a representative number of impacts indicates that the structural integrity of the exemplary club head is sufficient for field use. The results of the durability testing indicate that the inclusion of the lightweight shaft receiving structure provides mass property and performance advantages (as outlined in Examples 1 and 2) without sacrificing the durability of the club head.

[0170] (Provisions) (Clause 1) A golf club head comprising: a striking face; and a body, the striking face and the body being secured together to define an internal cavity, the body comprising: a crown; a sole opposite the crown; a heel; a toe opposite the heel; a skirt adjacent the crown and the sole; and a shaft receiving structure, the shaft receiving structure comprising: a hosel; and a shaft sleeve, the hosel being formed of a first material having a first density, the hosel comprising: a hosel wall defining at least a first portion of a hosel bore; a hosel wall upper portion defining a hosel bore opening; and a hosel base opposite the hosel bore opening, the hosel base being disposed on an inner surface of the sole adjacent the heel, the hosel defining a hosel bore axis concentric with the hosel bore, 11. A golf club head comprising: a shaft sleeve insertable into the hosel through the hosel bore opening and configured to connect a golf club shaft with the hosel; the hosel bore opening configured to receive the shaft sleeve; a lip formed at a bottom of the hosel wall upper portion; the shaft receiving structure further comprising a tube insert extending through the internal cavity from the lip to the hosel base, the tube insert being separated from the hosel bore opening by the hosel wall upper portion; the tube insert being formed of a second material having a second density less than the first density; the tube insert defining a remainder of the hosel bore; and the tube insert sealing the hosel bore from the internal cavity.

[0171] (Clause 2) The shaft receiving structure further includes a hosel length measured parallel to the hosel bore axis from the hosel bore opening to the hosel base, 2. The golf club head of claim 1, wherein the tube insert has a tube insert length measured from a top end to a bottom end of the tube insert, the tube insert length being 70-90% of the hosel length.

[0172] (Clause 3) The golf club head of Clause 2, wherein the tube insert length is between 1.00 inches and 1.50 inches.

[0173] (Clause 4) The golf club head described in Clause 1, wherein the lip is formed by a change in thickness between the upper portion of the hosel wall and the remaining portion of the hosel wall, the upper portion of the hosel wall having a greater thickness than the remaining portion of the hosel wall.

[0174] (Clause 5) The golf club head of clause 1, wherein the second material is selected from the group consisting of thermosetting resin, thermoplastic resin, filled thermoplastic material, fiber reinforced composite material, thermoplastic polyurethane (TPU) or thermoplastic elastomer (TPE), and aluminum alloy.

[0175] (Item 6) The second density is 3 g / cm 3 2. A golf club head as described in clause 1, wherein

[0176] (Clause 7) The golf club head described in Clause 1, wherein an upper end of the tube insert is retained by the lip, the shaft sleeve, and the hosel wall, and a lower end of the tube insert is retained by a bottom lap joint, the hosel base, and an end cap.

[0177] (Clause 8) The golf club head described in Clause 1, wherein the hosel wall defines a top lap joint adjacent the lip and the body defines a bottom lap joint extending from the hosel base to the internal cavity, and the tube insert is configured to be adhesively connected to the top lap joint and the bottom lap joint.

[0178] (Clause 9) A golf club head comprising: a striking face; and a body, the striking face and the body being fixed together to define an internal cavity, the body comprising: a crown; a sole opposite the crown; a heel; a toe opposite the heel; a skirt adjacent the crown and the sole; and a shaft receiving structure, the shaft receiving structure comprising: a hosel; and a shaft sleeve, the hosel being formed of a first material having a first density, the hosel comprising: a hosel wall defining at least a first portion of a hosel bore; a hosel bore opening located at an upper end of the hosel; and a hosel base opposite the hosel bore opening, the hosel base being formed on an inner surface of the sole adjacent the heel, the hosel defining a hosel bore axis concentric with the hosel bore, the shaft sleeve being insertable into the hosel through the hosel bore opening, 1. A golf club head configured to connect a golf club shaft with the hosel, the hosel bore opening configured to receive the shaft sleeve, the hosel further comprising a hosel wall upper portion proximate the hosel bore opening, the shaft receiving structure further comprising a tube insert extending through the internal cavity from the hosel wall upper portion to the hosel base, the tube insert being formed of a second material having a second density less than the first density, the tube insert defining a remainder of the hosel bore, the tube insert sealing the hosel bore from the internal cavity, the shaft receiving structure comprising a tube insert offset distance defined as the distance between the hosel bore opening and a top end of the tube insert, measured parallel to the hosel bore axis, the tube insert offset distance being greater than 0.20 inches.

[0179] (Clause 10) The golf club head of clause 9, wherein the shaft receiving structure has a mass that is at least 3 grams less than a mass of a similar shaft receiving structure formed solely of the first material.

[0180] (Clause 11) The golf club head of clause 9, wherein the second material is selected from the group consisting of thermosetting resin, thermoplastic resin, filled thermoplastic material, fiber reinforced composite material, thermoplastic polyurethane (TPU) or thermoplastic elastomer (TPE), and aluminum alloy.

[0181] (Clause 12) The second density is 3 g / cm 3 10. The golf club head of claim 9, wherein

[0182] (Clause 13) A golf club head comprising: a striking face; and a body, the striking face and the body being secured together to define an internal cavity, the body comprising: a crown; a sole opposite the crown; a heel; a toe opposite the heel; a skirt adjacent the crown and the sole; and a shaft receiving structure, the shaft receiving structure comprising: a hosel; and a shaft sleeve, the hosel being formed of a first material having a first density, the hosel comprising: a hosel wall defining at least a first portion of a hosel bore; and a hosel wall upper portion defining a hosel bore opening, the shaft sleeve being insertable into the hosel through the hosel bore opening and configured to connect a golf club shaft to the hosel. the hosel bore opening is configured to receive the shaft sleeve, a lower opening is located on the sole opposite the hosel bore opening, and an end cap is configured to connect to the sole and close the lower opening, the shaft receiving structure further comprising a tube insert extending through the internal cavity from the hosel wall upper portion to the end cap, the tube insert being formed of a second material having a second density less than the first density, the end cap being formed of a third material having a third density less than the first density, the tube insert defining a remainder of the hosel bore, and the tube insert sealing the hosel bore from the internal cavity.

[0183] (Clause 14) The golf club head of Clause 13, wherein the end cap further comprises one or more notches configured to receive a lower end of the tube insert.

[0184] (Clause 15) The golf club head described in Clause 13, wherein the end cap further comprises an end cap body and a protrusion extending upwardly from the end cap body, the protrusion extending at least partially within the hosel bore.

[0185] (Clause 16) The golf club head of Clause 13, wherein the end cap further comprises an opening extending through the end cap from the end cap lower surface to the end cap upper surface.

[0186] (Clause 17) The golf club head of Clause 13, wherein the tube insert is configured to be inserted into the internal cavity through the lower opening.

[0187] (Clause 18) The golf club head of clause 13, wherein the second material is selected from the group consisting of thermosetting resin, thermoplastic resin, filled thermoplastic material, fiber reinforced composite material, thermoplastic polyurethane (TPU) or thermoplastic elastomer (TPE), and aluminum alloy.

[0188] (Clause 19) The second density is 3 g / cm 3 14. The golf club head of claim 13, wherein

[0189] (Clause 20) The third density is 3 g / cm 3 14. The golf club head of claim 13, wherein

[0190] Replacement of one or more claimed elements constitutes a reconstruction, not a repair. Moreover, benefits, other advantages, and solutions to problems have been described with respect to certain embodiments. However, a benefit, advantage, solution to a problem, and an element that may give rise to or make more pronounced a benefit, advantage, or solution are not to be construed as a critical, essential, or essential feature or element of any or all of the claims unless such benefit, advantage, solution, or element is recited in a claim.

[0191] Moreover, the embodiments and limitations disclosed herein are not dedicated to the public under the doctrine of dedication if the embodiment and / or limitation (1) is not expressly recited in the claims, and (2) is an equivalent or potentially equivalent element and / or limitation recited in the claims under the doctrine of equivalents.

Claims

1. A golf club head, A striking face and A body; the striking face and the body are secured together to define an interior cavity; the body includes a crown, a sole opposite the crown, a heel, a toe opposite the heel, a skirt adjacent the crown and the sole, and a shaft receiving structure; The shaft receiving structure includes a hosel and a shaft sleeve. the hosel is formed of a first material having a first density; The hosel is a hosel wall defining at least a first portion of a hosel bore; an upper hosel wall defining a hosel bore opening; a hosel base opposite the hosel bore opening, the hosel base is provided on an inner surface of the sole in the vicinity of the heel, the hosel defines a hosel bore axis concentric with the hosel bore; the shaft sleeve is insertable into the hosel through the hosel bore opening and configured to connect a golf club shaft with the hosel; the hosel bore opening is configured to receive the shaft sleeve; a lip is formed at a bottom of the upper hosel wall; the shaft receiving structure further comprising a tube insert extending through the internal cavity from the lip to the hosel base; the tube insert is separated from the hosel bore opening by the hosel wall upper portion; the tube insert is formed of a second material having a second density less than the first density; the tube insert defines a remainder of the hosel bore; the tube insert seals the hosel bore from the internal cavity; Golf club head.

2. the shaft receiving structure further comprising a hosel length measured parallel to the hosel bore axis from the hosel bore opening to the hosel base; the tube insert having a tube insert length measured from a top end to a bottom end of the tube insert; 2. The golf club head of claim 1, wherein the tube insert length is 70-90% of the hosel length.

3. 3. The golf club head of claim 2, wherein the tube insert length is between 1.00 and 1.50 inches.

4. the lip is defined by a change in thickness between an upper portion of the hosel wall and the remaining portion of the hosel wall; The golf club head of claim 1 , wherein the hosel wall upper portion comprises a thickness greater than the remaining portion of the hosel wall.

5. 2. The golf club head of claim 1, wherein the second material is selected from the group consisting of thermosets, thermoplastics, filled thermoplastics, fiber reinforced composites, thermoplastic polyurethanes (TPUs) or thermoplastic elastomers (TPEs), and aluminum alloys.

6. The second density is 3 g / cm ３ The golf club head of claim 1 , wherein the axial length is less than 1 mm.

7. an upper end of the tube insert is retained by the lip, the shaft sleeve, and the hosel wall; The golf club head of claim 1 , wherein a lower end of the tube insert is retained by a bottom lap joint, the hosel base, and an end cap.

8. the hosel wall defines a top lap joint adjacent the lip; the body defines a bottom lap joint extending from the hosel base to the internal cavity; The golf club head of claim 1 , wherein the tube insert is configured to be adhesively connected to the top lap joint and the bottom lap joint.

9. A golf club head, A striking face and A body; the striking face and the body are secured together to define an interior cavity; the body includes a crown, a sole opposite the crown, a heel, a toe opposite the heel, a skirt adjacent the crown and the sole, and a shaft receiving structure; The shaft receiving structure includes a hosel and a shaft sleeve. the hosel is formed of a first material having a first density; The hosel is a hosel wall defining at least a first portion of a hosel bore; a hosel bore opening located at an upper end of the hosel; a hosel base opposite the hosel bore opening, the hosel base is formed on an inner surface of the sole in the vicinity of the heel, the hosel defines a hosel bore axis concentric with the hosel bore; the shaft sleeve is insertable into the hosel through the hosel bore opening and configured to connect a golf club shaft with the hosel; the hosel bore opening is configured to receive the shaft sleeve; the hosel further comprising an upper hosel wall portion adjacent the hosel bore opening; the shaft receiving structure further comprising a tube insert extending through the internal cavity from the hosel wall upper portion to the hosel base; the tube insert is formed of a second material having a second density less than the first density; the tube insert defines a remainder of the hosel bore; the tube insert seals the hosel bore from the interior cavity; the shaft receiving structure comprising a tube insert offset distance, measured parallel to the hosel bore axis, defined as the distance between the hosel bore opening and a top end of the tube insert; the tube insert offset distance is greater than 0.20 inches; Golf club head.

10. 10. The golf club head of claim 9, wherein the shaft receiving structure has a mass that is at least 3 grams less than a mass of a similar shaft receiving structure formed solely of the first material.

11. 10. The golf club head of claim 9, wherein the second material is selected from the group consisting of thermosets, thermoplastics, filled thermoplastics, fiber reinforced composites, thermoplastic polyurethanes (TPUs) or thermoplastic elastomers (TPEs), and aluminum alloys.

12. The second density is 3 g / cm ３ The golf club head of claim 9 , wherein the axial length is less than 1 mm.

13. A golf club head, A striking face and A body; the striking face and the body are secured together to define an interior cavity; the body includes a crown, a sole opposite the crown, a heel, a toe opposite the heel, a skirt adjacent the crown and the sole, and a shaft receiving structure; The shaft receiving structure includes a hosel and a shaft sleeve. the hosel is formed of a first material having a first density; The hosel is a hosel wall defining at least a first portion of a hosel bore; a hosel wall upper portion defining a hosel bore opening; the shaft sleeve is insertable into the hosel through the hosel bore opening and configured to connect a golf club shaft with the hosel; the hosel bore opening is configured to receive the shaft sleeve; a lower opening located on the sole opposite the hosel bore opening; an end cap configured to connect to the sole and close the lower opening; the shaft receiving structure further comprising a tube insert extending through the internal cavity from the upper portion of the hosel wall to the end cap; the tube insert is formed of a second material having a second density less than the first density; the end cap is formed of a third material having a third density less than the first density; the tube insert defines a remainder of the hosel bore; the tube insert seals the hosel bore from the internal cavity; Golf club head.

14. The golf club head of claim 13 , wherein the end cap further comprises one or more notches configured to receive a bottom end of the tube insert.

15. The end cap further comprises an end cap body and a projection extending upwardly from the end cap body, The golf club head of claim 13 , wherein the protrusion extends at least partially through the hosel bore.

16. The golf club head of claim 13 , wherein the end cap further comprises an opening extending through the end cap from a lower end cap surface to an upper end cap surface.

17. The golf club head of claim 13 , wherein the tube insert is configured to be inserted through the lower opening into the interior cavity.

18. 14. The golf club head of claim 13, wherein the second material is selected from the group consisting of thermosets, thermoplastics, filled thermoplastics, fiber reinforced composites, thermoplastic polyurethanes (TPUs) or thermoplastic elastomers (TPEs), and aluminum alloys.

19. The second density is 3 g / cm ３ The golf club head of claim 13 , wherein the axial length is less than 1 mm.

20. The third density is 3 g / cm ３ The golf club head of claim 13 , wherein the axial length is less than 1 mm.

Images