JP2024504383A - Golf club head with increased shaft joint strength - Google Patents

Abstract

Embodiments of golf clubs are described herein that include a club head, a shaft, and a mechanism that improves the joint strength between the club head and the shaft. The club head includes a hosel that receives the tip of the shaft. The shaft tip defines a shaft mating area and an effective mating area. The mechanisms described herein are designed to increase the effective shaft interface area with the hosel and improve the strength of the interface between the club head and the shaft. In some embodiments, the feature comprises a microgroove located within the shaft interface region. The microgrooves increase the effective bond area and provide multidirectional resistance to forces applied to the shaft. In some embodiments, the mechanism includes a ferrule that includes a weight mechanism that replaces a tip weight. In some embodiments, the mechanism includes a hot melt weight positioned within the shaft. [Selection diagram] Figure 13

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is filed in U.S. Provisional Application No. 63/217,683, filed on July 7, 2021, and in U.S. Provisional Application No. 63/140,747, filed on January 22, 2021. , the contents of which are fully incorporated herein by reference.

TECHNICAL FIELD This disclosure relates generally to golf clubs and, more particularly, to golf club shafts having various mechanisms for improving joint strength.

A typical golf club includes a shaft and a club head connected to the bottom end of the shaft, thereby forming a head-shaft connection ("connection"). During swing, the connection is subjected to multidirectional swing forces, also known as normal forces and torsional forces. During the swing, the club head is pulled away from the shaft, thereby exerting a normal force, and the club head also rotates or twists relative to the shaft, thereby exerting torsional forces on the connection. In addition to swing forces, the connection experiences impact forces when colliding with the ball. To prevent damage to the club head, the head-shaft connection must be strong enough to withstand these applied forces.

A connection is defined where the shaft tip is received by the hosel. Epoxy material is used to secure the shaft to the club head. The epoxy material forms a joint, or microlink, between the shaft tip and the hosel. The strength of the connection depends on the effective mating surface, or amount of the outer shaft surface that is in direct contact with the inner hosel surface. As the effective bond area increases, the bond strength also increases. The connection must have sufficient effective joint area to prevent the club head from flying off and causing catastrophic damage.

The effective joint area is limited by shaft insertion depth and hosel depth. In some golf clubs, the effective joint area is further limited by other components located within the hosel, such as ferrules, adjustable hosel sleeves, or tip weights. These components are used to improve other properties of the golf club. For example, tip weights provide a means to balance the club head and shaft to achieve a desired swing weight. However, these components require space within the hosel, which reduces the allowable effective joint area between the shaft and the hosel. In some golf clubs, to compensate for these additional components, the hosel is made larger (longer) to provide sufficient effective joint area. However, forming a larger hosel requires moving mass from the desired location to the hosel, which negatively impacts mass characteristics and sacrifices overall club head performance.

In view of the foregoing, further developments in the reinforcement of suitable golf club mechanisms can improve the performance of golf clubs while maintaining sufficient structural integrity of the golf club. Therefore, there is a need in the art for a golf club that improves the bond strength between the head and shaft while achieving the desired swing weight without adversely affecting mass properties and MOI.

FIG. 1 is an exploded cross-sectional view of a golf club according to a first embodiment.

2 is a cross-sectional view of the golf club of FIG. 1. FIG.

FIG. 3 is a cross-sectional view of a golf club according to a second embodiment.

1 is a side view of a golf club shaft with microgrooves according to a first embodiment; FIG.

FIG. 3B is an enlarged view of the microgroove of FIG. 3A.

FIG. 3 is a side view of a golf club shaft with microgrooves according to a second embodiment.

FIG. 3 is a side view of a golf club shaft with microgrooves according to a third embodiment;

FIG. 4 is a side view of a golf club shaft with microgrooves according to a fourth embodiment.

FIG. 5 is a side view of a golf club shaft with microgrooves according to a fifth embodiment;

FIG. 7 is a side view of a golf club shaft with microgrooves according to a sixth embodiment.

FIG. 7 is a side view of a golf club shaft with microgrooves according to a seventh embodiment.

FIG. 7 is a side view of a golf club shaft with microgrooves according to an eighth embodiment.

FIG. 2 is a perspective view of a ferrule according to the first embodiment.

FIG. 3 is a perspective view of a ferrule according to a second embodiment.

FIG. 12B is a perspective view of the internal weight of FIG. 12A.

FIG. 7 is a cross-sectional view of a ferrule according to a third embodiment.

FIG. 13B is a perspective view of the weight ring of the ferrule of FIG. 13A;

FIG. 7 is a side view of a ferrule according to a fourth embodiment.

1 is an exploded view of a golf club head with hot melt tip weights. FIG.

FIG. 15B is a cross-sectional view of the golf club head of FIG. 15A.

Golf clubs are described herein that include various features that increase the effective joint area between the shaft and the club head without adversely affecting club head characteristics. In some embodiments, the existing hosel and tip weight geometry is maintained and the shaft includes features according to aspects of the invention, such as microgrooves. In other embodiments, these hosel and tip weight geometries are modified such that the hosel and tip weights include features such as weighted ferrules or are replaced by features such as hot melt tip weights. will be corrected.

In some embodiments, as described above, the mechanism for increasing the effective interface area between the shaft and the golf club head includes microgrooves. Microgrooves increase connection strength in several ways. First, the microgroove is recessed into the shaft and defines a plurality of sidewalls, which increases the effective bond area. The sidewalls and floor of the microgroove provide a greater surface area than a flat shaft surface. Since the epoxy has a larger surface area to form the joint between the hosel and the shaft, the additional joint area increases the joint strength. Second, the microgrooves form pathways or channels that promote uniform epoxy flow around the shaft tip, which reduces the pressure between the hosel and the rest of the golf club head. Prevents build-up and air pockets. Finally, the sidewalls of each microgroove can be oriented differently to provide higher resistance to normal and/or torsional forces. The microgrooves create pathways that distribute stress more evenly across the connection. In some embodiments, microgrooves can be discrete lines, discrete shapes, intersecting lines, or intersecting shapes. The microgrooves can extend circumferentially around the effective bonding area or can be formed in groups. A group comprises a plurality of microgrooves having various shapes. Microgrooves can be formed in various patterns that define groups. The sidewalls of the microgroove may be smooth or jagged. Microgrooves can be applied to the tip of the shaft, the rear end of the shaft, or the inner surface of the grip. The microgrooves may include other features such as ridges, notches, areas of roughness, or any other features that increase the roughness of the effective bond area.

In other embodiments, as described above, the mechanism for increasing the effective joint area between the shaft and the golf club head replaces traditional perimeter weight and swing weight elements, such as tip weights. Contains weight elements such as . Removing the tip weight allows the shaft to be inserted deeper into the hosel, thereby maximizing shaft insertion depth. These weight elements can also be used in combination with smaller chip weights. In some embodiments, the weight element is a ferrule with a weight. The weight can be visible from the outside of the ferrule or hidden within the ferrule. In an alternative embodiment, the ferrule is formed from a high density material. In another embodiment, the weight element is a hot melt weight positioned within the shaft body. These weight elements provide substantial mass to add weight to the club head, thereby allowing the tip weight to be removed or replaced with a smaller tip weight. The weight elements described herein maximize the effective joint area to strengthen the head-shaft connection.

As used herein, the terms "comprising," "comprising," "having," "having," "capable," "including" and their conjugations do not exclude the possibility of additional features or structures. Intended to be an open-ended transitional phrase, term, or word. The singular forms "a," "and," and "the" include plural references unless the context clearly dictates otherwise. This disclosure relates to other embodiments "comprising," "consisting of," and "consisting essentially of" embodiments or elements presented herein, whether or not explicitly described. Also planned.

As used herein in the following disclosure, the term "about" is used in reference to a quantity that is inclusive of the recited value and has the meaning dictated by the context (e.g., at least in connection with the measurement of a particular quantity). (including some degree of error). Also, the modifier "about" should be construed as disclosing a range defined by the absolute values of the two endpoints. For example, the phrase "about 2 to about 4" also discloses a range of "2 to 4." The term "about" may refer to plus or minus 10% of the stated value. For example, "about 10%" may refer to a range of 9% to 11%, and "about 1" may mean 0.9 to 1.1. Other meanings of "about" may be apparent from the context.

As used in the following disclosure, the terms "first," "second," "third," and "fourth" are used to distinguish between similar elements and not necessarily in a particular sequential or chronological order. It is not used to state order. The terms so used are interchangeable under appropriate circumstances, such as to enable the embodiments described herein to operate in orders other than those illustrated or described herein. I would like you to understand that. Additionally, the terms "comprising" and "having" and their conjugations are intended to cover non-exclusive inclusion, including any process, method, system, item, device, or apparatus that includes a recitation of the elements. is not necessarily limited to these elements and may include other elements not explicitly listed or inherent to such a process, method, system, item, device, or apparatus.

As used in the following disclosure, the terms "circumferential," "parallel," "non-parallel," "perpendicular," and "non-perpendicular" are used for descriptive purposes and not necessarily to describe permanent relative positions. Not that it will be done. The terminology so used refers to the manner in which embodiments of the devices, methods, and/or articles of manufacture described herein permit operation in, for example, orientations other than those illustrated or described herein. is understood to be interchangeable under appropriate circumstances.

As used herein, "joint strength" can be the strength of the epoxy material at the head-shaft or grip-shaft connection. Bond strength can be quantified by the energy required to break the bond between the bonding surface and the inner hosel or grip surface.

As used herein, "coordinate system" includes a loft plane that is tangent to the geometric center of the striking surface. When the club head is in the address position, the club head defines a ground plane that is tangential to the sole. This coordinate system is defined by an origin at the geometric center of the golf club head striking surface. The surface center of the striking surface defines the origin for a coordinate system having an x-axis, a y-axis, and a z-axis. The x-axis is a horizontal axis extending through the center of the surface in a direction parallel to the ground plane from near the heel to near the toe. The y-axis is a vertical axis that extends perpendicularly to the ground plane from near the sole to near the crown and passes through the center of the surface. The y-axis is perpendicular to the x-axis. The z-axis is a horizontal axis that extends parallel to the ground plane from near the front to near the rear, and passes through the center of the plane. The z-axis is perpendicular to the x- and y-axes. The x-axis extends in a positive direction toward the heel. The y-axis extends in a positive direction toward the crown. The z-axis extends in a positive direction toward the rear.

As used herein, a "center of gravity coordinate system" is defined at the center of gravity of a golf club head. The center of gravity is located within the coordinate system defined above. The center of gravity can also have a location on the x, y, and z axes. The center of gravity further defines the origin of a coordinate system having CGx, CGy, and CGz axes. The CGx axis extends through the CG from near the heel to near the toe. The CGy axis extends through the CG from near the crown to near the sole, and the CGy axis is perpendicular to the CGx axis. The CGz axis extends through the CG from near the front to near the rear, and is perpendicular to both the CGx and CGy axes.

As used herein, "effective bond area" may be the surface area of the shaft outer surface that is in direct contact with the hosel bore inner surface. The effective bond area may extend circumferentially around the shaft outer surface and may be located along the effective bond depth. The effective joint area may be located within the shaft joint area. FIG. 2A shows an example of the effective bond area 154.

As used herein, "effective bond depth" may be the depth of the shaft outer surface in direct contact with the hosel bore inner surface. FIG. 2A shows an example of an effective bond depth 156, which can be measured along longitudinal axis 110 from ferrule bottom edge 2012 to shaft bottom end 144. FIG. 2B shows another example of effective bond depth 156, which is measured along longitudinal axis 110 from ferrule bottom edge 2012 to tip weight 192.

As used herein, "epoxy" can be any adhesive or resin mixture used to join a shaft to a club head or grip. Epoxy is applied to the shaft joint area and is used as a means to secure the connection. The epoxy can form a bond between the shaft bonding region and the hosel or grip inner surface.

As used herein, "ferrule depth" can be the length of the ferrule lower portion or centering region that enters the hosel. FIG. 2A shows an example of ferrule depth 2030, which is measured along longitudinal axis 110 from ferrule ledge 2018 to ferrule bottom edge 2012.

As used herein, a "ferrule surface" can be the surface area of the lower portion of the ferrule that contacts the hosel junction area. FIG. 2A shows an example of a ferrule surface 2046 that extends circumferentially around the lower ferrule portion and is located at ferrule depth 2030.

As used herein, a "golf club" can be an iron-type golf club, a wood-type golf club, or a putter-type golf club. Iron-type golf clubs can be cavity, cavity back, hollow body, forged, cast, crossover golf club heads. A wood type golf club can be a driver, fairway, or hybrid type golf club head.

As used herein, a "head-shaft connection" can be a connection between the outer surface of the shaft tip and the inner surface of the hosel. Head-shaft connection may be used interchangeably with "connection."

As used herein, a "hosel interface area" can be the surface area of the inner hosel bore surface that interfaces with the shaft. FIG. 1 shows an example of a hosel bonding region 138 that extends circumferentially around the hosel bore inner surface and is located along the hosel depth 134.

As used herein, "hosel depth" may be the total depth of the hosel hole measured along the longitudinal axis. FIG. 1 shows an example of hosel depth 134, which is measured from hosel hole rim 126 to hosel hole base 128.

As used herein, an "iron-type golf club head" includes the top rail, sole, heel, toe, rear, and striking surface. Generally, iron-type golf club heads include one unitary body with a striking face and a hosel formed together. In other embodiments, the striking surfaces can be individually formed.

As used herein, a "longitudinal axis" may be an axis extending from the geometric center of the top end of the shaft to the geometric center of the bottom end of the shaft. The shaft may be a symmetrical cylindrical body bisected by a longitudinal axis.

A "moment of inertia" as used herein may be a moment of inertia Ixx and/or Iyy. The moment of inertia Ixx is defined about the CGx axis (ie, the crown-to-sole moment of inertia) and the moment of inertia Iyy is defined about the CGy axis (ie, the heel-toe moment of inertia). Moment of inertia represents the ability of a golf club head to withstand twisting.

As used herein, a "normal force" can be a tensile force applied normal or perpendicular to the cross-sectional area of the shaft. In other words, the normal force can be applied parallel to the longitudinal axis of the shaft. Normal force is sometimes used interchangeably with "push force" or "pull force." A normal force is applied to the shaft and may cause a uniform normal stress across the cross-sectional area of the object.

As used herein, a "shaft interface area" may be the surface area of the shaft that interfaces with the inner hosel bore surface. The shaft interface region can extend circumferentially around the shaft outer surface and can be located at the shaft insertion depth. FIG. 1 shows an example of a shaft bonding region 150 that includes an effective bonding region 154 and a ferrule outer surface 2046.

As used herein, "shaft insertion depth" may be the depth of a shaft inserted into a hosel hole. FIG. 1 shows an example of shaft insertion depth 152, which is measured along longitudinal axis 110 from shaft tip 144 to ferrule ledge 2018.

As used herein, a "tip weight" can be a cylindrical weight component that can be inserted into a hosel and held in place with an epoxy material. The tip weight can be formed from a high density material. FIG. 2B shows an example of a tip weight 190 located near the hosel base 128 and having a tip weight depth 192 measured along the longitudinal axis 110.

A "torsion force" as used herein can be a twisting force applied parallel or tangential to the cross-sectional area of the shaft. In other words, the torsional force may be applied perpendicular to the longitudinal axis of the shaft. Torsional force can be used interchangeably with torque or torsional force. Torsional forces may be applied to the shaft, causing a distribution of shear stress across the cross-sectional area of the shaft.

As used herein, a "transition step" can be a transition region located on the outer surface of the shaft near the bottom end. A transition step can be defined as a transition between the shaft mating surface and the remainder of the shaft located above the shaft mating area. In some embodiments, a transition step can be defined by a change in surface finish. For example, the portion of the shaft above the transition step may have a polished finish, and the portion of the shaft below the transition step may have a sand blast finish. In other embodiments, the transition step may be defined by a change in the outer diameter of the shaft. For example, a portion of the shaft above the transition step may have a larger diameter than a portion of the shaft below the transition step.

As used herein, a "wood-type golf club head" can include a striking surface and a body that are fixed together to define a substantially closed/hollow interior volume. The club head includes a crown, a sole opposite the crown, a heel, a toe opposite the heel, a front, and a rear opposite the front. The body may further include a skirt or trailing edge positioned between and adjacent the crown and sole, the skirt extending from near the heel to near the toe of the club head.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, this document, including definitions, will control. Preferred methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.

A golf club is described herein that includes a feature that increases the strength of the bond between a club head and a shaft. Bond strength is enhanced when the effective bond area is increased and when the epoxy is allowed to flow evenly around the shaft. This can be done either by maintaining the current hosel and ferrule geometry while also increasing the mating surface area, or by modifying the ferrule so that the current mechanism can be removed, thereby increasing shaft insertion depth and mating surface area. This can be achieved by increasing the

The golf club described herein includes a club head 100, a shaft 140, and a grip 160. Club head 100 includes a body 120 and a hosel 122, and hosel 122 includes a hosel hole 124. Hosel hole 124 is defined by an inner surface extending from hosel rim 126 to hosel base 128. The inner surface defines a hosel interface region 138 that interacts with shaft 140. Hosel bond area 138 is the inner surface of hole 122 used to bond hosel 122 to shaft 140. Shaft 140 includes a top end 142 received within grip 160, a bottom end 144 received within hosel hole 124, and an outer surface 146. Outer surface 146 defines a transition step 148 and a shaft interface region 150 near bottom end 144 . Shaft bond area 150 is the surface of shaft 140 that is used to bond shaft 140 to hosel 122. Shaft bottom end 144 is positioned within hosel hole 124 such that shaft mating region 150 contacts hosel mating region 138 . The interaction between shaft interface region 150 and hosel interface region 138 forms the connection between club head 120 and shaft 140. Additionally, the configuration of shaft interface region 150 and hosel interface region 138 determines the strength of the head-shaft connection.

The portion of shaft interface region 150 that is in direct contact with hosel interface region 138 is known as effective interface region 154 . In most embodiments, the effective bond area 154 is smaller than the shaft bond area 150 and is limited by the presence of other components within the hosel bore. As discussed above, it is desirable to maximize the effective bond area 154 to strengthen the head-shaft connection. One way to maximize the effective bond area 154 is to increase the effective bond depth 156 by removing additional components. Maximum effective bond depth 156 is equal to shaft insertion depth 152 and effective bond area 154 is equal to shaft bond area 150. In such embodiments, the entire shaft interface area 150 directly contacts the hosel interface area 138. In other embodiments where additional components are present, the effective bond area 154 is maximized while remaining within the existing footprint.

For example, some golf clubs further include a ferrule 2000 positioned around the shaft 140. Referring to FIG. 2A, ferrule 2000 includes a lower portion that is inserted into hosel hole 124 at ferrule depth 2030. The lower portion of ferrule 2000 includes an outer surface 2046 that contacts hosel bonding area 138, which prevents shaft bonding area 150 (at ferrule depth 2030) from contacting hosel bonding area 138. Effective bond depth 156 is thereby reduced by ferrule depth 2030. In other embodiments, the golf club further includes a tip weight 190 located in the hosel hole base 128. Tip weight 190 occupies space within hosel hole 124, thereby reducing allowable shaft insertion depth 152. Effective bond area 154 is reduced by chip weight depth 192. This disclosure describes several mechanisms designed to increase the effective joint area 154 to increase the joint strength between the club head 100 and the shaft 140. The golf clubs described herein can include any combination of these features.

A. Golf Club Shaft with Microgrooves As discussed below, shaft 140 can include a plurality of microgrooves. The microgrooves increase the effective bond area 154 without increasing the effective bond depth 156. Microgrooves can be used to improve bond strength while maintaining other desirable hosel features such as ferrule, tip weight, and hosel size.

Referring to FIGS. 3A-10, golf club shaft 140 can further include a plurality of microgrooves. In some embodiments, microgrooves are located within the shaft junction region 150. In other embodiments, the microgrooves are located only within the effective bonding area 154. The microgrooves strengthen the head-shaft connection by increasing the effective bond area and providing multidirectional resistance to forces. The microgroove is recessed into the shaft and defines a plurality of sidewalls, each sidewall defining a depth of the microgroove and a sidewall surface area. The sidewall surface area provides additional area for the effective bond area 154. Thus, the microgrooves increase the effective bond area 154 without increasing the effective bond depth 156. The microgroove is integrally formed with the shaft 140, which makes it a versatile mechanism that can be applied to any shaft 140 without changing the existing footprint of the shaft 140 and/or hosel mechanism. In some embodiments, the microgroove can have two sidewalls and a planar floor that define a U-shaped channel in cross-section. In other embodiments, the microgroove can have two angled sidewalls that connect to form a V-shaped channel.

In addition to increasing the effective bond area 154, the microgrooves allow the sidewalls to provide resistance to the various forces applied to the shaft 140 (and the head-shaft connection) during the swing and impact with a golf ball. Directed. During the downswing, the shaft 140 is subjected to a normal force applied parallel to the longitudinal axis 110 in a direction from the trailing end of the shaft 140 to the leading end such that the club head is pulled away from the shaft. Shaft 140 is further subjected to torsional forces applied perpendicular to longitudinal axis 110 upon impact with a golf ball such that the golf club head rotates about the shaft axis. The microgroove sidewalls provide resistance when directed in a direction non-parallel to the applied force. In other words, the microgroove sidewalls provide resistance to normal forces when oriented non-parallel to the longitudinal axis 110 and provide resistance to torsional forces when oriented non-perpendicular to the longitudinal axis 110.

The microgrooves each define a depth measured from the shaft outer surface 146 to the floor of each microgroove. Alternatively, microgroove depth can also be referred to as microgroove sidewall height. In some embodiments, the sidewalls are perpendicular to the shaft outer surface 146. In other embodiments, the sidewalls are angled relative to the shaft outer surface 146. Microgroove depth correlates to an increase in sidewall surface area and effective bond area 154. The same amount of force applied to a larger surface area has a smaller effect because the force is more widely distributed. Therefore, the microgroove depth is maximized to improve bonding properties. However, the microgroove depth depends on the thickness of the shaft 140. The microgroove depth is limited to prevent the microgrooves from penetrating too deeply. Too deep a penetration may compromise the strength of the shaft 140.

Additionally, the microgrooves provide epoxy pathways or channels that extend circumferentially around the shaft outer surface 146. These channels promote uniform epoxy flow around the shaft 140, which maximizes the surface covered by epoxy and further increases bond strength. Thus, the microgrooves allow for multidirectional forces while maximizing the effective bond area 154 and promoting uniform epoxy coverage. In some embodiments, the microgroove sidewalls are oriented non-parallel and non-perpendicular to the longitudinal axis 110, as defined above, thereby providing resistance to both normal and torsional forces. .

The microgrooves can be formed in any combination of discrete or intersecting shapes, each shape comprising at least three sidewalls. The microgrooves can be formed as groups of at least two microgrooves. However, each group can comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 or more microgrooves. Further, the microgrooves can be formed as 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 or more groups of microgrooves. Microgrooves can be formed as multiple discrete or intersecting lines. Alternatively, the microgrooves can also be formed as a plurality of randomly oriented elements. Microgrooves can be formed in any combination described herein. However, the microgrooves can preferably be configured to provide resistance to both normal forces and torsional forces. The positioning and sizing of the microgrooves is selected to reinforce the head-shaft connection without compromising the strength of the shaft. As discussed below, microgrooves can be formed in a variety of shapes and lines with varying sizes.

The microgroove depth is between 0.0010 inch and 0.0050 inch. In some embodiments, the microgroove depth is less than about 0.0010 inches, 0.0015 inches, 0.0020 inches, 0.0025, 0.0030 inches, 0.0035 inches, or 0.0040 inches. be. In some embodiments, the microgroove depth is between 0.0010" and 0.0025", between 0.0010" and 0.0050", between 0.0015" and 0.0030", and between 0.0025" and 0.0025". 0.0040 inches, or between 0.0035 inches and 0.0050 inches. In one exemplary embodiment, the microgroove depth is 0.0030 inches. Microgrooves can be applied to both graphite and steel shafts. In some graphite shafts, the microgrooves are recessed into the outer resin layer of shaft 140 but do not penetrate the inner composite layer.

In some embodiments, the microgroove depth is constant throughout the microgroove, while in other embodiments, the microgroove depth varies throughout the microgroove. In some embodiments, the microgroove depth varies such that the microgrooves are deeper near the bottom shaft end 144 and shallower toward the top shaft end 142. Conversely, in other embodiments, the microgroove depth varies such that the microgrooves are deeper near the shaft top end 142 and shallower toward the shaft bottom end 144. The microgroove depth can vary in any pattern, or the microgroove depth can vary randomly. Furthermore, the depth can also vary in any direction within each individual microgroove.

The microgroove depth can be adjusted to provide microgrooves with greater bearing capacity in particular portions of the shaft interface region 150. For example, the shaft 140 may experience a non-uniform stress distribution due to applied torsional forces, and thus deeper microgrooves may be positioned where the effective bond area 154 experiences greater stress. For example, shaft 140 may be stressed more at the top end of shaft interface region 150 than at the bottom end of shaft interface region 150 due to torsional forces, and thus shaft interface The apex of region 150 benefits from deep microgrooves. The microgroove depth is optimized to increase the effective bond area 154 without compromising the strength of the shaft 140. Microgroove lengths and widths are similarly selected to provide greater bearing capacity in portions of the effective bond area 154.

Each microgroove further defines a respective microgroove length measured along longitudinal axis 110 from the point of the microgroove closest to shaft bottom end 142 to the point closest to shaft top end 144 . Each microgroove further includes a respective microgroove width measured circumferentially around shaft 140 in a direction perpendicular to longitudinal axis 110. The individual microgroove length and width determine the increase in effective bond area 154.

In some embodiments, the individual microgroove lengths are constant across the microgrooves, while in other embodiments the individual microgroove lengths vary across the microgrooves. In some embodiments, the individual microgroove lengths are 0.05 inches, 0.10 inches, 0.25 inches, 0.50 inches, 0.75 inches, 1.00 inches, 1.25 inches, Less than 1.50 inches, 1.75 inches, 3.00 inches, 3.50 inches, or 5.00 inches. In some embodiments, the individual microgroove lengths are from 0.05 inches to 0.10 inches, from 0.075 inches to 0.125 inches, from 0.075 inches to 0.20 inches, from 0.25 inches to 0.50 inch, 0.50 inch to 1.00 inch, 0.75 inch to 1.50 inch, 1.10 inch to 1.50 inch, 1.25 inch to 3.00 inch, or 2.00 inch ~5.00 inches. In one exemplary embodiment, the individual microgroove length is 0.75 inches. A microgroove may have the same length as an adjacent microgroove or a different length. Individual microgroove lengths can be adjusted to provide microgrooves with greater load bearing capacity in particular portions of the shaft interface region 150. For example, longer microgrooves can be positioned where shaft 140 experiences greater stress.

In some embodiments, the individual microgroove widths are constant across the microgrooves, while in other embodiments the individual microgroove widths vary across the microgrooves. In some embodiments, the individual microgroove width is less than 0.05 inch, 0.10 inch, 0.25 inch, 0.50 inch, 0.75 inch, or 1.00 inch. In some embodiments, the individual microgroove widths are from 0.05 inches to 0.50 inches, from 0.075 inches to 0.125 inches, from 0.075 inches to 0.20 inches, from 0.25 inches to 0. .50 inches, 0.30 inches to 0.75 inches, 0.50 inches to 1.00 inches, 0.75 inches to 1.50 inches, or 1.00 inches to 2.00 inches. In one exemplary embodiment, the individual microgroove width is 0.015 inches. Microgrooves may have the same width as adjacent microgrooves or different widths. The individual microgroove widths can be adjusted to provide microgrooves with greater load bearing capacity in particular portions of the shaft interface region 150. For example, wider microgrooves can be positioned where shaft 140 experiences greater stress.

The surface area of each microgroove sidewall is determined by the depth, length, and width of each microgroove. The microgroove sidewalls increase the effective bond area 154 and increase bond strength by providing additional surface area for the epoxy to bond. In some embodiments, the microgrooves have an effective bond area 154 of 0.01 in ² , 0.05 in ² , 0.10 in ² , 0.25 in ² , 0.50 in ² , 0.75 in ² , 1.00 in ² , 1.25 in ² , or 1.50 in ² . In some embodiments, the microgrooves increase the effective bond area 154 by more than 5%, 10%, 15%, 20%, 30%, 50%, 75%, or 90%. In other embodiments, the microgrooves reduce the effective bond area 154 by 5% to 10%, 5% to 15%, 10% to 25%, 25% to 50%, 50% to 75%, or 75% to Increase by an amount between 90%. The microgrooves form microchannels that increase the effective junction area 154. The increase in effective bond area 154 enhances bond strength at the head-shaft connection by providing more surface area for forming additional bonds.

The microgrooves further include a total depth measured from the microgroove closest to the shaft bottom end 144 to the microgroove closest to the shaft top end 142 along the longitudinal axis. The total microgroove depth is different from the individual microgroove depths. Total microgroove depth is the actual length of the shaft with microgrooves. In some embodiments, the microgrooves cover the entire shaft interface region 150, and the total microgroove depth is equal to the shaft insertion depth. In other embodiments, the microgrooves are located only within the effective bond area 154 and the total microgroove depth is equal to the effective bond depth 156. In some embodiments, the total microgroove depth is greater than 0.90 inches, 1.00 inches, 1.10 inches, 1.20 inches, 1.30 inches, or 1.35 inches. In some embodiments, the total microgroove depth is between 0.50 inches and 1.00 inches, between 0.50 inches and 1.50 inches, between 0.60 inches and 0.90 inches, and between 0.70 inches and 1 .10 inches, 0.80 inches to 1.10 inches, 1.20 inches to 1.75 inches, 1.50 inches to 3.00 inches, or 2.50 inches to 5.00 inches. In one exemplary embodiment, the total microgroove depth is 1.10 inches.

The total microgroove depth determines the portion of shaft bonding region 150 that is covered by the microgrooves. In some embodiments, the microgrooves cover 10% to 20%, 25% to 50%, 25% to 75%, 30% to 80%, 50% to 70%, 50% to 90% of the shaft interface area 150. %, between 60% and 100%, or between 75% and 100%. The microgrooves are formed in a continuous pattern without large gaps between adjacent microgrooves. In some embodiments, the microgrooves are uniformly distributed, while in other embodiments, the microgrooves are concentrated over several portions of the shaft interface region 150. The microgroove sizing is selected to increase the effective bond area 154 without compromising the strength of the shaft 140. The microgroove sizing and shaping discussed above can be applied to the various embodiments of microgrooves described herein.

The golf clubs described herein can include any combination of the microgroove patterns described below. In some embodiments, the microgrooves are formed as lines, and in other embodiments, the microgrooves are formed into specific shapes. As discussed above, in some embodiments, each microgroove is recessed into shaft 140 and defined by a plurality of sidewalls (or "sidewalls") and a planar floor. In other embodiments, the microgroove is defined by two sidewalls recessed into the shaft 140 and forming a V-shaped or U-shaped channel. The orientation of the sidewalls is expressed relative to the longitudinal axis 110. The sidewalls can be oriented horizontally (perpendicular to longitudinal axis 110), vertically (parallel to longitudinal axis 110), or obliquely to longitudinal axis 110 (angled to longitudinal axis 110). The orientation of the microgrooves is selected to provide multidirectional resistance to forces applied to the golf club shaft. Each sidewall may be a smooth continuous surface, or the sidewalls may be jagged. Additionally, the microgrooves may be intersecting or discrete lines.

I. Microgrooves Formed as Lines In some embodiments, microgrooves can be formed as multiple lines, as shown in FIGS. 3A-8. Microgrooves 1100, 1200, 1300, 1400, 1500 are described using like reference numbers. For example, microgrooves 1100, 1200, 1300, 1400, 1500 include side walls 1110, 1210, 1310, 1410, 1510 and floors 1120, 1220, 1320, 1420, 1520.

In some embodiments (see FIGS. 3A and 3B), the microgrooves 1100 extend circumferentially around the shaft 140 in a direction oblique to the longitudinal axis 110 such that the orientation is neither perpendicular nor parallel. be able to. In other words, the microgroove 1100 extends helically around the shaft. Microgroove 1100 has a first group 1130 and a second group 1140. The first group 1130 of microgrooves 1100 extends helically around the shaft in a clockwise direction up and down. A second group 1140 of microgrooves 1100 extends helically around the shaft in a counterclockwise direction up and down. The first and second groups 1130, 1140 of microgrooves 1100 intersect to form a diamond-shaped protrusion between the microgrooves 1100.

Microgroove 1100 forms an angle with longitudinal axis 110. The angle is measured from the longitudinal axis to the sidewall 1110 of the microgroove 1100. The angle can be within a range of greater than 0 degrees and less than 90 degrees in a direction measured clockwise or counterclockwise from longitudinal axis 110. For example, as shown in FIGS. 3A and 3B, one set of microgrooves 1100 forms a 45 degree angle measured in a clockwise direction, and a second set of microgrooves 1100 forms a 45 degree angle measured in a counterclockwise direction. and form a 45 degree angle. In other embodiments, the microgrooves are 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, measured in a clockwise or counterclockwise direction with respect to the longitudinal axis 110. , 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, or 85 degrees.

In other embodiments, as shown in FIG. 4, the microgrooves 1200 can extend circumferentially around the shaft 140 in a direction perpendicular to the longitudinal axis 110 such that they do not intersect. Sidewalls 1210 are parallel to each other and perpendicular to longitudinal axis 110. Sidewalls 1210 provide resistance to normal forces.

In another embodiment, the microgrooves 1300 can extend in a direction parallel to the longitudinal axis 110, as shown in FIG. Microgrooves 1300 are positioned circumferentially around shaft 140 and do not intersect. Sidewalls 1310 are parallel to each other and parallel to longitudinal axis 110. Sidewalls 1310 provide resistance to torsional forces.

In another embodiment, the microgrooves can include a first plurality of microgrooves 1200 and a second plurality of microgrooves 1300, as shown in FIG. The sidewalls 1210 of the first plurality of microgrooves 1200 are parallel to each other and perpendicular to the longitudinal axis 110, and the sidewalls 1310 of the second plurality of microgrooves 1300 are parallel to each other and perpendicular to the longitudinal axis 110. parallel to 110. The first plurality of microgrooves 1200 can be located higher than the second plurality of microgrooves 1300 or closer to the shaft top end 142. As shown in FIG. 6, the first plurality of microgrooves 1200 can also be located below the second plurality of microgrooves 1300. Microgrooves 1200, 1300 provide resistance to normal and torsional forces.

The first plurality of microgrooves 1200 and the second plurality of microgrooves 1300 each include at least one microgroove. In some embodiments, the first and second pluralities of microgrooves 1200, 1300 each have 10-20 microgrooves, 20-50 microgrooves, 10-30 microgrooves, 30-70 microgrooves, etc. microgrooves, 50 to 100 microgrooves, 40 to 60 microgrooves, 50 to 150 microgrooves, or 30 to 50 microgrooves. In other embodiments, the microgrooves can further comprise a third plurality of microgrooves, a fourth plurality of microgrooves, or a fifth plurality of microgrooves.

In another embodiment, as shown in FIG. 7, the microgrooves 1400 can extend circumferentially around the shaft 140 in a direction perpendicular to the longitudinal axis 110 such that they do not intersect. Sidewall 1410 defines a jagged or non-straight sidewall section 1410. Each sidewall section 1410 is angled relative to adjacent sidewall sections 1410. Additionally, each sidewall section 1410 is oriented non-parallel and non-perpendicular to longitudinal axis 110. Angled sidewall sections 1410 provide resistance to normal and torsional forces.

In another embodiment, as shown in FIG. 8, the microgrooves 1500 can extend circumferentially around the shaft 140 in a diagonal direction relative to the longitudinal axis 110. In this embodiment, microgrooves 1500 are generally parallel to each adjacent microgroove 1500. Microgroove 1500 is similar to microgroove 1400 shown in FIG. 7, with sidewalls 1510 defining sidewall sections 1510. Sidewall sections 1510 are angled relative to adjacent sidewall sections 1510. Additionally, each sidewall section 1510 is oriented non-parallel and non-perpendicular to longitudinal axis 110. Angled sidewall sections 1510 provide resistance to normal and torsional forces.

II. Microgrooves formed in specific shapes In some embodiments, the microgrooves are formed as a plurality of lines, as shown in FIGS. 9 and 10. Microgrooves 1600, 1700 are described using similar reference numbers. For example, microgrooves 1600, 1700 include sidewalls 1610, 1710 and floors 1620, 1720. As discussed above, each microgroove is recessed into shaft 140 by a plurality of sidewalls (or "sidewalls") and a floor. The sidewall defines the shape of the microgroove.

Each microgroove defines a shape that may be the same or different from the remaining microgrooves. Microgrooves may be circles, lines, triangles, squares, rectangles, polygons, or any combination of any suitable shapes. The microgrooves can intersect or overlap, or they can be discrete shapes. Microgrooves can be formed in multiple rows or even in groups.

A group of microgrooves is defined by a dense collection of microgrooves. The groups of microgrooves can be equally spaced or can vary in spacing. Furthermore, the microgrooves within each group can be equally spaced or can vary in spacing. The spacing and density of the microgrooves within each group and across all groups can be selected such that the microgrooves can provide greater normal or torsional drag on some portions of the shaft 140.

Similar to groups of microgrooves, microgrooves can be organized into rows. The rows of microgrooves can be equally spaced or can vary in spacing. Furthermore, the microgrooves in each row can be equally spaced or can vary in spacing. The spacing and density of the microgrooves in each row and across all rows can be selected such that the microgrooves can provide greater vertical or torsional resistance to some portions of the shaft 140. Each microgroove may define a shape that may be the same or different from adjacent microgrooves in the same row. Furthermore, the microgrooves can have the same shape in each row, or can have different shapes across multiple rows.

In some embodiments, microgrooves 1600 can be formed as groups 1630, as shown in FIG. Group 1630 takes the shape of a hexagon. Each group 1630 includes six triangular microgrooves 1600.

In other embodiments, the microgrooves 1700 can be formed in several rows 1740 extending circumferentially around the shaft 140, as shown in FIG. Microgroove 1700 has a triangular shape. The microgrooves 1700 have different sizes across multiple rows 1740, with the top row of microgrooves 1700 being smaller than the bottom row of microgrooves 1700.

Additionally, microgrooves 1600 and 1700 may be circles, lines, triangles, squares, rectangles, polygons, or any combination of any suitable shapes. Sidewalls 1610 and 1710 can be oriented non-parallel or non-perpendicular to longitudinal axis 110. Each microgroove 1600 and 1700 thus forms at least one of a vertical resistance component or a torsional resistance component. Each group and row 1630 and 1740 can be oriented perpendicular to longitudinal axis 110 or non-perpendicular to longitudinal axis 110. Each group and row 1630 and 1740 can include at least one microgroove 1600 and 1700. For example, each group and row 1630 and 1740 can include 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 or more microgrooves 1600 and 1700. Additionally, one or more groups or rows 1630 and 1740 may be present. For example, there may be one, two, three, four, five, or more groups 1630 and rows 1740. Groups and rows 1630 and 1740 can be equally spaced or can vary in spacing. The spacing and density of microgrooves 1600 and 1700 can be selected to provide greater normal or torsional drag on some portions of shaft 140.

A golf club shaft 140 incorporating microgrooves as described herein provides advantages over shafts known in the art. Primarily, the microgrooves (1) allow the epoxy to flow evenly around the shaft tip, (2) increase the total effective bond area, and (3) provide resistance to normal and torsional forces. By providing a stronger joint between the club head and the shaft. When a conventional shaft is pressed into a hosel, the epoxy spreads unevenly around the shaft and concentrates near the bottom of the hosel. As a result, pressure can build up within the hosel and create trapped air pockets within the epoxy. These trapped air pockets can be seen by cutting open the hosel and looking at the cross section after the shaft has been joined. Confirm trapped air pockets by creating a test hosel made of a transparent material (not used in the actual club) such as plastic so that the interior of the hosel can be seen during shaft insertion. You can also do that. Trapped air pockets weaken the bond strength and provide stress failure propagation points. The microgrooves provide a path for the epoxy to flow evenly around the shaft, thereby reducing pressure build-up within the hosel and greatly reducing or even eliminating air pocket porosity. Additionally, microgrooves reduce epoxy wastage because less epoxy is needed to create a uniform distribution. The sidewalls of the microgroove provide additional surface area for the epoxy to form a microlink between the shaft tip and the hosel bore inner surface. Additionally, the sidewalls are oriented at least non-parallel or non-perpendicular to the longitudinal axis to resist forces applied parallel or perpendicular to the longitudinal axis. Increasing the bond strength allows club designers to add weight components, such as tip weights, to the hosel. The microgrooves compensate for the reduction in bond strength caused by the loss of shaft insertion depth. Additionally, the microgroove is a versatile mechanism that can be used with both right-handed and left-handed clubs.

B. Golf Clubs with Weighted Ferrules This specification further describes various embodiments of weighted ferrules that replace traditional tip weights by removing mass from the tip weight and redistributing that mass to the ferrule. By removing the mass due to the tip weights, the tip weights can be completely eliminated or significantly reduced in size. Removing the tip weight or reducing the tip weight size allows the shaft 140 to be inserted deeper into the hosel hole 124, thereby increasing the effective bond area 154 and improving bond strength. Tip weight 190 includes a tip weight depth 192 that reduces allowable shaft insertion depth 152 (and effective bond depth 156), as shown in FIG. 2B. Chip weight depth 192 may range from 0.1 inch to 0.5 inch. For example, tip weight depth 192 can be 0.1 inch, 0.2 inch, 0.25 inch, 0.3 inch, 0.35 inch, 0.40 inch, or 0.5 inch. In some embodiments, tip weight 190 is used to manipulate the center of gravity (CG) of club head 100 or adjust the swing weight of club head 100.

Accordingly, in the embodiments discussed below, tip weight 190 may be removed or replaced with a smaller tip weight 190, which increases shaft insertion depth 152. In some embodiments, the shaft insertion depth is increased by an amount between 0.10 inches and 0.50 inches. The increased shaft insertion depth 152 increases the effective joint area 154, thereby increasing joint strength at the head-shaft connection.

In some embodiments, referring to FIGS. 11-14, the golf club further includes a ferrule 2000 positioned around the shaft outer surface 146. In some embodiments, referring to FIGS. Shaft bottom end 142 extends through ferrule 2000 and into club head 120 . The ferrule 2000 centers the shaft 140 within the hosel 122 and covers the blunt hosel top rim to create a smooth transition from the hosel 122 to the shaft 140. Referring to FIG. 11, ferrule 2000 is a cylindrical body with a top edge 2010 proximal to grip 160 and a bottom edge 2012 proximal to club head 120. Referring to FIG. The ferrule further includes an inner surface 2014 that contacts the shaft 140 and an externally exposed outer surface 2016. Ferrule 2000 further includes a ferrule ledge 2018 that defines a transition between the upper and lower portions of the ferrule. The upper portion is a tapered region 2020 exposed above the hosel 122. The lower portion is a centering area 2040 located within hosel 122.

A centering region 2040 is defined between ferrule ledge 2018 and bottom edge 2012. Centering region 2040 is received within hosel 122 such that ferrule ledge 2018 is flush with the hole top rim. Centering region 2040 includes a plurality of windows 2042 and a plurality of ribs 2044. The multiple windows 2042 increase the path for excess epoxy to flow around the centering region 2040, increasing bond strength. The plurality of ribs 2044 act as a self-centering mechanism. Ribs 2044 are evenly spaced throughout centering region 2040 and apply an equal amount of pressure against hosel hole 124 to prevent shaft 140 from entering hosel 122 at an angle. Centering region 2040 is the lower portion of ferrule 2000 that is received within hosel 122 and tapered region 2020 is the upper portion that is exposed above hosel 122.

A tapered region 2020 is defined between ferrule ledge 2018 and top edge 2010. Tapered region 2020 tapers from a maximum outer diameter 2060 to a smaller diameter near top edge 2010. Tapered region 2020 creates a smooth transition from shaft diameter 140 to hosel diameter 122. In some embodiments, tapered region 2040 accommodates a weight element.

Ferrule 2000 is formed from a resin that can have a density of 0.9 g/cm ³ to 1.5 g/cm ³ . In some embodiments, the density is 0.9 g/cm ³ to 1.0 g/cm ³ , 1.0 g/cm ³ to 1.1 g/cm 3 , 1.1 g/cm ^{3 to} 1.2 g/cm ³ , 1.2 g/cm ³ to 1.3 g/cm ³ , 1.3 g/cm ³ to 1.4 g/cm ³ , or 1.4 g/cm ³ to 1.5 g/cm ³ . For example, in one embodiment, the resin can have a density of 1.19 g/cm ³ . In some embodiments, the resin comprises cellulose acetate propionate (CAP) resin. The ferrule material is lightweight and does not provide a means of adding weight to the golf club head 120. Accordingly, in some embodiments, ferrule 2000 further comprises a weight element. Various embodiments of weight elements are discussed below. In some embodiments, the weight element comprises a weight. In other embodiments, the weight element comprises a ferrule formed from a dense material.

Various embodiments of the weight elements described below are formed from metallic materials such as stainless steel, tungsten, tungsten-tenite propionate (TPU) mixtures, or stainless steel-tenite propionate (TPU) mixtures. The weight element material is denser than the ferrule material. The density of the weight element material is between 1 g/cm ³ and 18 g/cm ³ . In some embodiments, the weight element material has a density of 1 g/cm ³ to 2 g/cm ³ , 2 g/cm ³ to 3 g/cm ³ , 3 g/cm ³ to 4 g/cm ³ , 4 g/cm ³ to 5g/cm ³ , 5g/cm ³ ~6g/cm ³ , 6g/cm ³ ~7g/cm ³ , 7g/cm ³ ~8g/cm ³ , 8g/cm ³ ~9g/cm ³ , 9g/cm ³ ~ 10g/cm ³ , 10g/cm ³ ~11g/cm ³ , 11g/cm ³ ~12g/cm ³ , 12g/cm ³ ~13g/cm ³ , 13g/cm ³ ~14g/cm ³ , 14g/cm ³ ~ 15 g/cm ³ , 15 g/cm ³ to 16 g/cm ³ , 16 g/cm ³ to 17 g/cm ³ , or 17 g/cm ³ to 18 g/cm ³ .

The various embodiments of weight elements described below define heights measured along longitudinal axis 110. The height is measured between the top perimeter of the weight element and the bottom perimeter of the weight element. In some embodiments, the height is between 0.3 inches and 0.7 inches. In some embodiments, the height is between 0.3 inches and 0.45 inches, between 0.35 inches and 0.40 inches, between 0.40 inches and 0.60 inches, and between 0.45 inches and 0.60 inches. , 0.50 inch to 0.55 inch, 0.52 inch to 0.57 inch, 0.53 inch to 0.60 inch, or 0.54 inch to 0.60 inch. In some embodiments, the height is about 0.3 inches, 0.31 inches, 0.32 inches, 0.33 inches, 0.34 inches, 0.35 inches, 0.36 inches, 0.37 inches. inch, 0.38 inch, 0.39 inch, 0.40 inch, 0.41 inch, 0.42 inch, 0.43 inch, 0.44 inch, 0.45 inch, 0.46 inch, 0.47 inch, 0.48 inch, 0.49 inch, 0.5 inch, 0.51 inch, 0.52 inch, 0.53 inch, 0.54 inch, 0.55 inch, 0.56 inch, 0.57 inch, 0.58 inch, 0.59 inch, 0.6 inch, 0.61 inch, 0.62 inch, 0.63 inch, 0.64 inch, 0.65 inch, 0.66 inch, 0.67 inch, 0.68 inch, 0.69 inch, or 0.7 inch.

The various embodiments of weight elements described below further define a thickness measured between the inner and outer surfaces of the weight element. In some embodiments, the thickness remains constant across the weight element, while in other embodiments the thickness varies across the weight element. The thickness is between 0.01 inch and 0.09 inch. In some embodiments, the thickness is between 0.01 inch and 0.05 inch, between 0.01 inch and 0.07 inch, between 0.03 inch and 0.08 inch, and between 0.04 inch and 0.09 inch. , or between 0.05 inch and 0.09 inch. In some embodiments, the thickness is about 0.01 inch, 0.02 inch, 0.03 inch, 0.04 inch, 0.05 inch, 0.06 inch, 0.07 inch, 0.08 inch. inch, or 0.09 inch. In one exemplary embodiment, the thickness near the top perimeter is 0.031 inches and the thickness near the bottom perimeter is 0.062 inches. In another exemplary embodiment, the thickness near the top perimeter is 0.021 inches and the thickness near the bottom perimeter is 0.055 inches.

Ferrule 2000 with weight elements and resin material defines a mass between 1 gram and 12 grams. In some embodiments, the mass is between 1 gram and 5 grams, 2 grams and 7 grams, 3 grams and 6 grams, 5 grams and 10 grams, or 6 grams and 12 grams. In other embodiments, the mass is 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, 7 grams, 8 grams, 9 grams, 10 grams, 11 grams, or 12 grams. The mass of the ferrule 2000 is selected to provide a substantial weight element to the club head for manipulating the club head CG and/or achieving a desired swing weight.

The ferrule 2000 comprising weight elements and resin material further defines an average density in the range of 1 g/cm ³ to 6 g/cm ³ . The average density is the ratio of the total mass of ferrule 2000 to the total volume of ferrule 2000. For example, the average density may be 2.95 g/ ^cm3 . In other embodiments, the ferrule 2000 is 1 g/cm ³ , 1.5 g/cm ^{3 , 2 g/cm 3 ,} 2.5 g/cm ³ , 3 g/cm ³ , 3.5 g/cm ³ , 4 g/cm ³ , 4.5 g/cm ³ , 5 g/cm ³ , 5.5 g/cm ³ , or 6 g/cm ³ .

Ferrule 2000 comprising a weight element and resin material has a mass increase rate of 300% to 2500% compared to a ferrule comprising only resin material. In some embodiments, the mass increase rate is 300% to 400%, 400% to 500%, 500% to 600%, 600% to 700%, 700% to 800%, 800% to 900%, 900%. ～1000%, 1000%～1100%, 1100%～1200%, 1200%～1300%, 1300%～1400%, 1400%～1500%, 1500%～1600%, 1600%～1700%, 1700%～1800 %, 1800% to 1900%, 1900% to 2000%, 2000% to 2100%, 2100% to 2200%, 2200% to 2300%, 2300% to 2400%, or 2400% to 2500%.

The weight element can be an internal weight positioned between the ferrule inner surface and the shaft, a weight ring extending circumferentially around the ferrule outer surface, or a ferrule made of a high density material. The weight element replaces traditional tip weights by removing the mass due to the tip weight and redistributing that mass to the ferrule. By removing the mass due to the tip weights, the tip weights can be completely eliminated or significantly reduced in size. Removing the tip weight or reducing the tip weight size allows the shaft 140 to be inserted deeper into the hosel hole 124, thereby increasing the effective bond area 154 and improving bond strength.

I. Ferrule with Internal Weight In one embodiment (see FIG. 12A), ferrule 2000 includes internal weight 2100. Internal weight 2100 provides substantial mass to ferrule 2000 to manipulate the club head CG and forms a weight element that can replace a tip weight. Referring to FIG. 12A, internal weight 2100 is integrally formed with ferrule 2000 near tapered region 2020. Internal weight 2010 extends throughout tapered region 2020. However, in other embodiments, internal weight 2100 extends through only a portion of tapered region 2020.

Referring to FIG. 12B, the internal weight 2100 is cylindrical and includes a top periphery 2110 proximal to the ferrule top edge 2010 and a bottom periphery 2120 proximal to the ferrule bottom edge 2012. Internal weight 2100 further includes an inner surface 2130 that forms a portion of ferrule inner surface 2014 and an outer surface 2140 that contacts ferrule 2000. Internal weight 2100 defines a gap 2150 extending from top periphery 2110 to bottom periphery 2120. When ferrule 2000 is pushed over shaft 140, gap 2150 relieves stress across ferrule 2000.

Gap 2150 defines a gap width measured across the aperture. Gap width ranges from 0.01 inch to 0.5 inch. In some embodiments, the gap width is between 0.01 inch and 0.05 inch, between 0.02 inch and 0.04 inch, between 0.03 inch and 0.07 inch, and between 0.04 inch and 0.09 inch. , 0.05 inch to 0.10 inch, 0.10 inch to 0.25 inch, 0.15 inch to 0.45 inch, 0.20 inch to 0.40 inch, 0.25 inch to 0.50 inch , 0.30 inch to 0.5 inch, or 0.40 inch to 0.50 inch. Gap widths are approximately 0.01 inch, 0.02 inch, 0.03 inch, 0.04 inch, 0.05 inch, 0.06 inch, 0.07 inch, 0.08 inch, 0.09 inch, 0.10 inch, 0.15 inch, 0.20 inch, 0.25 inch, 0.30 inch, 0.35 inch, 0.40 inch, 0.45 inch, or 0.50 inch. In one exemplary embodiment, the gap width is 0.03 inches. The gap width is selected to provide stress relief to the ferrule 2000 without significantly reducing the mass of the internal weight 2100. The dimensions of the internal weight are further selected to provide substantial weight-adding functionality.

Internal weight 2100 defines a height between 0.5 inches and 0.6 inches. In some embodiments, the height is between 0.50 inches and 0.55 inches, between 0.52 inches and 0.57 inches, between 0.53 inches and 0.60 inches, or between 0.54 inches and 0.60 inches. Between inches. Height is approximately 0.5 inch, 0.51 inch, 0.52 inch, 0.53 inch, 0.54 inch, 0.55 inch, 0.56 inch, 0.57 inch, 0.58 inch, 0.59 inch, 0.6 inch, 0.61 inch, 0.62 inch, 0.63 inch, 0.64 inch, 0.65 inch, 0.66 inch, 0.67 inch, 0.68 inch, 0.69 inch or 0.7 inch. In one exemplary embodiment, the height is 0.653 inches. Internal weight 2100 is hidden within ferrule 2000 and is not exposed on ferrule outer surface 2016. In other embodiments, the weight elements are exposed on the outer surface 2016 of the ferrule.

II. Ferrule with Weighted Rings Referring to FIGS. 13A-14, in some embodiments, ferrule 2000 can include one or more weighted rings. The weighted ring provides substantial mass to the ferrule 2000, manipulates the club head CG, and forms a weight element that can replace the tip weight. A weighted ring is integrally formed with ferrule 2000 and extends circumferentially around tapered region 2020. The weighted ring may be one ring, two rings, three rings, four rings, five rings, or any other suitable number of rings. In some embodiments, the weighted rings have the same height, and in other embodiments, the weighted rings have different heights.

Referring to FIGS. 13A and 13B, ferrule 2000 further includes a single weighted ring 2200. Referring to FIGS. Weighted ring 2200 includes a top periphery 2210 proximal to ferrule top edge 2010 and a bottom periphery 2220 proximal to ferrule bottom edge 2012 . Weighted ring 2200 further includes an inner surface 2230 adjacent ferrule outer surface 2016 and an outer surface forming a portion of ferrule outer surface 2016.

Referring to FIG. 14, the ferrule 2000 further includes two weighted rings 2300. Each weighting ring 2300 includes a top periphery 2310 proximal to the ferrule top edge 2010 and a bottom periphery 2320 proximal to the ferrule bottom edge 2012. Each weighted ring 2300 further includes an inner surface 2330 adjacent the outer ferrule surface 2016 and an outer surface forming a portion of the outer ferrule surface 2016.

III. Ferrules Formed from High Density Materials In another embodiment, the weight mechanism comprises a high density ferrule similar to the ferrules disclosed in previous embodiments. The ferrule can be molded from a dense resin mixture so that the ferrule 2000 has a suitable mass to replace the tip weight. The resin mixture can include a combination of resin and filler material. In some embodiments, the resin can include cellulose acetate propionate (CAP) resin. The filler material can be selected from the group consisting of steel or tungsten. The resin mixture can have a specific gravity of 1-9. In some embodiments, the specific gravity is between 1-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8, 8-9, or 9-10. obtain.

The overall mass of a high density ferrule can be from 0.1 grams to 20 grams. For example, high density ferrules are 0.1 grams to 2 grams, 2 grams to 4 grams, 4 grams to 6 grams, 6 grams to 8 grams, 8 grams to 10 grams, 10 grams to 12 grams, and 12 grams to 14 grams. , 14 grams to 16 grams, 16 grams to 18 grams, 18 grams to 20 grams. The mass of the ferrule can be selected to provide a substantial weight element.

The weighted ferrule described herein is designed to replace the tip weight 190, thereby allowing the shaft 140 to be inserted deeper into the hosel bore 124. The increased shaft insertion depth 152 increases the effective joint area 154, thereby increasing joint strength at the head-shaft connection. Additionally, the ferrule 2000 with the weight elements described above improves mass properties such as MOI and CG. Ferrule 2000 is located above hosel 122 and closer to the periphery of club head 100 than tip weight 190. Thus, ferrule 2000 shifts mass closer to the periphery of club head 100, thereby improving the moment of inertia (MOI) of club head 100.

C. Golf Club Head with Hot Melt Weights Similar to the weighted ferrule embodiment described above, another embodiment is further described herein that provides an alternative means for adding weight to a shaft. In this embodiment, hot melt weights are injected into the tip of the shaft and the added mass increases the overall weight of the shaft. As mentioned above, adding weight to the shaft can increase the overall shaft insertion depth by removing or reducing the size of the tip weight.

In one embodiment, club head 100 may include a ferrule 2000, similar to the embodiments described above. Shaft 140 can further include a hot melt weight 3000 and a cap 3050, as shown in FIGS. 15A and 15B. Hot melt weight 3000 may be formed inside shaft 140 along longitudinal axis 110. Hot melt weight 3000 can be positioned within hosel hole 124 near shaft bottom end 144 . A cap 3050 may be near the bottom end 144 to secure the hot melt weight 3000 within the shaft 140. In some embodiments, hot melt weight 3000 can extend from shaft bottom end 144 to ferrule bottom edge 2012. In other embodiments, the hot melt weight can extend from the bottom end 144 to the top edge of the ferrule. Hot melt weight 3000 can extend from bottom end 144 to any suitable length within shaft 140 to form the desired mass.

Hot melt weight 3000 can be made partially of a thermoplastic polymer. For example, hot melt weights can be made from butyl rubber (BR), hydrocarbon resins, polybutenes, process oils, or any combination thereof. In some embodiments, hot melt weight 3000 includes 30% BR, 50% hydrocarbon resin, 15% polybutene, and 5% process oil. Hot melts are solid at room temperature, but can become liquid when activated by a heating element. The hot melt weight 3000 is liquid when injected into the tip of the shaft and becomes solid when cooled. Hot melt weight 3000 is bonded to the inner surface of the shaft to prevent movement of hot melt weight 3000 within the shaft.

Hot melt weight 3000 can be partially formed from a metal filler material. The metal filler material can form part of the hot melt composition described above. The metal filler material can include any suitable dense material such as tungsten powder. The metal filler material increases the overall density of hot melt weight 3000 to achieve sufficient weight to be able to replace chip weight 190. The metal filler material can add any amount of weight with an accuracy of 0.1 grams.

The hot melt weight 3000 can range from 0.1 grams to 20 grams. For example, Hot Melt Weight 3000 is 0.1 g to 2 g, 2 g to 4 g, 4 g to 6 g, 6 g to 8 g, 8 g to 10 g, 10 g to 12 g, and 12 g to It can range from 14 grams, 14 grams to 16 grams, 16 grams to 18 grams, 18 grams to 20 grams.

The weight mechanism described herein provides several advantages over traditional perimeter weights. Removing the tip weight allows the shaft to penetrate further into the hosel, increasing surface area for bonding and reducing the amount of club head breakage in the field. Additionally, removing the tip weight also eliminates vibrations or rattles caused by loose tip weights. These weight mechanisms move mass closer to the periphery than traditional tip weights, increasing MOI and creating a more forgiving club. The filler material used to form the weights allows any amount of weight to be added with high precision.

Methods The golf club 100 described herein can be manufactured by a variety of methods. As discussed above, golf club 100 includes at least a club head, a shaft, and a grip. Different embodiments of each feature can be combined to form numerous variations of golf club 100. The shaft may include any one or more of the microgrooves 1000, 1100, 1200, 1300, 1400, or 1500 variations as described above. Manufacturing methods may vary for different variations of golf club 100. An exemplary method of manufacturing golf club 100 is described below.

A method of manufacturing a club head 100 having microgrooves 1000, 1100, 1200, 1300, 1400, 1500 includes (1) forming a shaft 140; (2) microgrooves 1000, 1100, 1200, 1300, 1400; . and inserting. In step 1, shaft 140 may be a graphite shaft or a steel shaft. The shaft is formed by warping a sheet of prepreg around a steel mandrel, coating the prepreg material with resin, curing the shaft 140, and removing the steel mandrel. In step 2, the shaft 140 can be rotated using a shaft spinner, which can apply any variant of the microgrooves 1000, 1100, 1200, 1300, 1400, 1500 to the shaft. do. The application of microgrooves 1000, 1100, 1200, 1300, 1400, 1500 may depend on the shaft material used. For example, a 3D printer is used to etch microgrooves 1000, 1100, 1200, 1300, 1400, 1500 in the outer resin layer. In step 3, the microgrooves 1000, 1100, 1200, 1300, 1400, 1500 formed near the tip of the shaft allow the epoxy to flow evenly around the tip of the shaft, which is reduces pressure build-up and air pockets.

A method of manufacturing a club head 100 with a ferrule 2000 includes the steps of (1) forming weight mechanisms 2100, 2200, 2300 from a first material; and (2) forming the ferrule 2000 using a second material. (3) inserting the shaft 140 into the ferrule 2000; (4) fixing the shaft 140 and the ferrule 2000 to the hosel 122; (5) the ferrule. (6) assembling toe weights. In step 1, the first material can include a metal consisting of stainless steel, tungsten, a tungsten-tenite propionate (TPU) mixture, or a stainless steel-tenite propionate (TPU) mixture. In step 2, ferrule 2000 may be injection molded around weight mechanism 2100, 2200, 2300. The second material can include resin. In some embodiments, the resin may consist of cellulose acetate propionate (CAP) resin. In step 3, in some embodiments, the shaft 140 can be inserted into the ferrule 2000 so that the gap 2150 relieves stress. In step 4, epoxy may be used to secure the shaft within hosel 122. A plurality of ribs 2024 located on ferrule 2000 help center shaft 140 within hosel 122 by applying circumferential pressure to hosel bore 124 . A plurality of windows 2042 located in ferrule 2000 allow excess epoxy to flow around ferrule 2000, increasing the bond strength between shaft 140 and hosel 122. In step 5, the ferrule 2000 can be blended with acetone to ensure that the ferrule 2000 is flush with the hole top rim 126. In step 6, screws can be used to secure the toe weights.

A method of manufacturing a club head 100 with a high density ferrule (not shown) includes the steps of: (1) forming a ferrule from a high density resin mixture; (2) inserting a shaft 140 into the ferrule; ) securing the shaft 140 and ferrule to the hosel 122; (4) blending the ferrule; and (5) assembling toe weights. In step 1, the ferrule can be injection molded. The resin mixture can include a combination of resin and filler material. In some embodiments, the resin can include cellulose acetate propionate (CAP) resin and the filler material can be steel or tungsten. In step 3, epoxy may be used to secure shaft 140 within hosel 122. A plurality of ribs 2044 located on ferrule 2000 help center shaft 140 within hosel 122 by applying circumferential pressure to hosel bore 124 . A plurality of windows 2042 located in ferrule 2000 allow excess epoxy to flow around ferrule 2000, increasing the bond strength between shaft 140 and hosel 122. In step 4, the ferrule 2000 may be blended with acetone to ensure that the ferrule 2000 is flush with the hosel hole rim 126. In step 4, screws can be used to secure the toe weights.

A method of manufacturing a club head 100 with a hot melt weight 3000 includes the steps of: (1) forming a hot melt weight using a first material; and (2) securing a cap 3050 to the bottom shaft end 144. (3) hardening the hot melt weight 3000; (4) forming the ferrule 2000 using a second material; and (5) inserting the shaft 140 into the ferrule 2000. , (6) fixing shaft 140 and ferrule 2000 to hosel 122, (7) blending ferrule 2000, and (8) assembling toe weights. In step 1, a hot melt weight 3000 may be formed near the bottom shaft end 144. The first material, or hot melt solution, can include a metal and a filler material. In some embodiments, the filler material can include tungsten powder. In step 2, the cap 3050 can include a centering cap or Christmas tree plug that can be press-fit onto the shaft bottom end 144. Cap 3050 can prevent hot melt solution from leaking from shaft 140. In step 3, the golf club may be positioned within the curing carousel such that the hot melt weight 3000 may be located near the bottom shaft end 144. In step 4, ferrule 2000 can be injection molded. In some embodiments, the second material can include a resin. In other embodiments, the second material can include a resin mixture that includes a combination of a resin and a filler material. In some embodiments, the resin can include cellulose acetate propionate (CAP) resin and the filler material can be steel or tungsten. At step 6, epoxy may be used to secure shaft 140 within hosel 122. A plurality of ribs 2044 located on ferrule 2000 help center shaft 140 within hosel 122 by applying circumferential pressure to hosel bore 124 . A plurality of windows 2042 located in ferrule 2000 allow excess epoxy to flow around ferrule 2000, increasing the bond strength between shaft 140 and hosel 122. At step 7, the ferrule 2000 may be blended with acetone to ensure that the ferrule 2000 is flush with the hosel hole rim 126. At step 8, screws may be used to secure the toe weights.

A. Example A: Microgroove Tensile Test A tensile test was conducted to demonstrate the effect of microgrooves on epoxy tensile strength. This tensile test used various shafts to measure the normal force required before the head-shaft connection failed. Each shaft was formed with or without microgrooves, and the insertion depth of the shaft was varied. For each sample shaft, the effective weld depth was the same as the shaft insertion depth. The purpose of this tensile test was to determine how much additional strength could be gained by adding microgrooves and increasing shaft insertion depth.

The first sample shaft was a control shaft with no microgrooves and a shaft insertion depth of 1.1 inches. A control shaft tip was prepared using the sanding method currently used to manufacture shafts. The second shaft was the first exemplary shaft with microgrooves similar to those shown in FIGS. 3A and 3B. The first exemplary shaft had a shaft insertion depth of 1.1 inches. The third shaft was also the second exemplary shaft with microgrooves similar to those shown in FIGS. 3A and 3B. The second exemplary shaft had a FSD of 1.3 inches and had microgrooves. The microgrooves of the first and second exemplary shafts were similar, but the shaft insertion depths were varied. The microgrooves included first and second pluralities of interconnected microgrooves applied throughout the shaft interface area.

Tensile testing was performed by holding the club stationary and pulling the shaft away from the club head. Three sample shafts were tested five times each, ending each test when the epoxy joint failed explosively (failure was indicated by a flying club head). Tensile testing measured the force at which the connection failed at a specific displacement. This force represents the strength of the head-shaft connection. This test measured the average strength of each of the five tensile tests and the minimum strength for each sample shaft. In each test, the same amount of epoxy was used on each sample shaft, keeping the microgroove depth and pattern constant for the exemplary shaft.

The results of this tensile test are shown in Table 1 above. This tensile test concluded that the shaft with microgrooves had higher epoxy tensile strength. The average epoxy tensile strength of the control shaft was 2756.77 lbf with a standard deviation of 151.14 lbf. The minimum epoxy tensile strength of the control shaft was 2589.37 lbf.

The average epoxy tensile strength of the first exemplary shaft was 3269.15 lbf with a standard deviation of 102.27 lbf. The average epoxy tensile strength of the first exemplary shaft was increased by 18.59% (512.38 lbf) over the control shaft. The first exemplary shaft had a minimum epoxy tensile strength of 3153.92 lbf, an increase of 21.80% over the control shaft. Although the control shaft and the first exemplary shaft had the same shaft insertion depth, the first exemplary shaft had a larger effective bond area due to the presence of the microgrooves. The first exemplary shaft exhibited additional strength of the shaft when adding microgrooves while keeping the shaft insertion depth constant.

The average epoxy tensile strength of the second exemplary shaft was 3470.13 lbf with a standard deviation of 174.21 lbf. The average epoxy tensile strength of the second exemplary shaft was increased by 25.88% (713.36 lbf) over the control test. The minimum epoxy tensile strength of the second exemplary shaft was 3292.90 lbf, an increase of 27.17%. The second exemplary shaft had a deeper shaft insertion depth than both the control shaft and the first exemplary shaft. By increasing the shaft insertion depth from 1.1 inches to 1.3 inches, the average epoxy tensile strength of the second exemplary shaft increased by 200.98 lbf compared to the first exemplary shaft. . A second exemplary shaft demonstrated additional strength of the shaft when increasing shaft insertion depth. Tensile tests concluded that introducing microgrooves into the shaft and increasing the shaft insertion depth significantly increases the bond strength between the club head and the shaft.

B. Example B: Microgroove tensile test (hosel/microgroove comparison)
A tensile test similar to that in Example A was conducted to demonstrate the effect of microgroove depth and to compare the bond strength between microgrooves located in the hosel and microgrooves located in the shaft. This tensile test determines the maximum force that the club head/shaft connection can withstand before it fails. The greater the force, the stronger the connection. This tensile test compared two exemplary club heads according to one embodiment to a control club head.

The control club head included a club head body, a hosel, and a shaft. The shaft had no microgrooves. The hosel had microgrooves on the inner surface of the hosel hole. The grooves ran perpendicular to the longitudinal axis 110. The grooves were parallel and evenly spaced so that they did not intersect. Additionally, the grooves had a depth of 0.003 inches. Groove depth did not sacrifice shaft durability.

The first exemplary club head had a shaft with horizontal microgrooves, as shown in FIG. The shaft had four microgrooves that were equally spaced and parallel so that they did not intersect. The microgrooves had a depth of 0.002 inches.

The second sample, like the first sample, had a shaft with horizontal microgrooves, as shown in Figure 4. The shaft had four microgrooves that were equally spaced and parallel so that they did not intersect. The microgrooves had a depth of 0.006 inches.

The results of this tensile test are shown in Table 3 above. This tensile test concluded that club heads with microgrooves in the shaft have higher bond strength than club heads with microgrooves in the hosel. Furthermore, this test concluded that deeper microgrooves have higher bond strength than shallower microgrooves.

The first exemplary club head had a joint strength of 2198.60 lbf, an increase of 163.62 lbf (8%) over the control club head. Therefore, a shaft with microgrooves has better bond strength than a hosel with microgrooves.

The second exemplary club head had a bond strength of 2308.91 lbf, an increase of 273.93 lbf (13.4%) over the control club head. Additionally, the second exemplary club head had an increase of 110.31 lbf over the first exemplary club head. Increasing the groove depth from 0.002 inch to 0.006 inch increased the bond strength.

C. Example C: Ferrule Extreme Temperature Testing Extreme temperature (ET) testing was conducted to evaluate the durability of several ferrules with different weight elements under extreme temperature control conditions. The purpose of this test is to determine how several weighted ferrule designs perform under stress over a wide range of temperatures. In other words, the ET test demonstrated the flexibility and fracture resistance of the weighted ferrule design.

Three different weighted ferrule designs were tested on assembled golf clubs. In each of the three ET tests, one of the ferrule designs was evaluated, and four to five sample golf clubs each having the same ferrule design were used. Each sample golf club was assembled using its respective weighted ferrule and allowed to cure for 24 hours before testing. Each sample was placed in a freezer at approximately 0°F for approximately 2 hours. The temperature of the sample was measured when removed from the freezer. This sample was then used to perform 30 "cold" hits near the low toe area of the club face. The temperature of each sample was then taken after 30 cold blows. The samples were then placed in an oven at about 200°F for about 2 hours. The temperature of the test sample was taken when removed from the oven. Again, this sample was then used to perform 30 "hot" hits near the low toe area of the club face. The temperature of each sample was then taken after 30 high temperature blows. It was determined whether each sample passed or failed the ET test. Rejected samples show signs of wear, such as cracks, breaks, chips, or kinks. In contrast, passing samples show no signs of wear.

Each sample was an iron-shaped golf club. The weighted ferrule material was kept constant throughout the three tests. Each sample included a ferrule formed from CAP resin, which is used to form conventional ferrules. Each sample further included an internal weight made of steel. Three tests evaluate ferrules with internal weights of different masses and dimensions. The dimensions of the internal weight, such as outer diameter and height, were adjusted throughout the test to balance the mass and volume of the internal weight material and the ferrule body material. The balance of materials affects the strength and flexibility of the ferrule. Another important dimension is the curvature of the internal weight edge. The internal weight includes an upper edge and a lower edge, each having a curvature. The curvature was adjusted throughout the test to reduce stress points across the ferrule.

First Test: In the first ET test, five test samples were used. The mass of the internal weight was 3.69 grams and the mass of the assembled ferrule was 4.54 grams. The edge curvature was 0.1 inch. The results of the first ET are shown in Table 1 below. Each sample passed the first 30 shots and failed the next 30 shots. The first test had a pass rate of 0%.

Second Test: The second ET test also used five test samples. The mass of the internal weight was 3.80 grams and the mass of the assembled ferrule was 4.60 grams. The internal weight height was 0.65 inches and the outside diameter was 0.490 inches. The internal weight used in the second test contained more rounded corners (greater curvature). Corners can become stress points, and removing them can prevent cracks. The curvature was changed from 0.1 inch to 0.4 inch. The results of the second ET are shown in Table 2 below. In the second test, only two of the samples failed and three of the five samples passed. The second test had a pass rate of 60%.

Third Test: Four samples were used in the third ET test. The mass of the internal weight was X grams and the mass of the assembled ferrule was X grams. Compared to the second test sample, the outer diameter of the internal weight was reduced from 0.490 inches to 0.436 inches, and the length was reduced from 0.65 inches to 0.63 inches. The outer diameter was reduced compared to the second test, but still larger than the outer diameter of the ferrule in the first test. The third test again used a ferrule with rounder corners than the sample used in the first test. The curvature was reduced from 0.4 inches to 0.3 inches. The results of the third ET are shown in Table 3 below. In the third ET test, all four samples passed. In the third test, the pass rate was 100%.

The results of three tests demonstrate the effect of internal weight dimensions on durability. These results indicate that reducing the height and diameter of the weight improves the durability of the ferrule. Furthermore, increasing the curvature of the rounded corners improves the durability of the ferrule. The weight and ferrule geometry used in Test 3 had a 100% pass rate. Therefore, the weighted ferrule design is durable and can be successfully implemented into products without damage.

D. Example D: Example Mass Properties of Weighted Ferrules Comparative testing was conducted between an exemplary club head with a weighted ferrule and a control club head with a ferrule and tip weight. This test was conducted to compare the center of gravity position and moment of inertia characteristics. The center of gravity and moment of inertia characteristics are defined within the coordinate system and center of gravity coordinate system described above. In this test, computer-aided design software was used to determine the location of the center of gravity and moment of inertia.

The exemplary club head included a club head, shaft, and weighted ferrule similar to the embodiment shown in FIGS. 12A and 12B. The weighted ferrule had a total weight of 7.35 grams. The exemplary club head did not have a tip weight and therefore inserted the shaft deeper into the hosel to improve joint strength.

The control club head had the same club head geometry as the exemplary club head. The control club head further included a ferrule having a mass of 1.35 grams. The control club head ferrule did not have a weighted element. The control club head also had a 6 gram tip weight such that the shaft insertion depth was less than that of the exemplary embodiment described above.

The exemplary club head had a CG position along the x-axis. CGx was 0.065 inch. The exemplary club head further included a CG position along the y-axis. CGy was 0.631 inch. The exemplary club head further included an MOI about the x-axis. Ixx was 139.7. The exemplary club head further included an MOI about the y-axis. Iyy was 545.6.

The control club head had a CG position along the x-axis. CGx was 0.048 inch. The control club head had a CG position along the y-axis. CGy was 0.598 inch. The control club head had an MOI around the x-axis. Ixx was 118.6. The control club head had an MOI around the y-axis. Iyy was 523.

The exemplary club head had a CGx position that was 0.017 inches farther along the x-axis (towards the heel) than the control club head. Additionally, the exemplary club head had a CGy position that was 0.033 inches further along the y-axis (upward) than the control club head. The exemplary club head had a 17.8% increase in Ixx compared to the control club head. The exemplary club head had a 4.3% increase in Iyy compared to the control club head.

Accordingly, the exemplary club head with the weighted ferrule exhibited an increased moment of inertia about both the x-axis and the y-axis when compared to a control club head with tip weights. The increased moment of inertia provides the exemplary club head with improved performance over a control club head. Additionally, the weighted ferrule further improves bond strength because the shaft is inserted deeper into the hosel than a comparable club head with tip weights.

Clause 1: A golf club comprising a club head, a shaft, and a grip, the club head comprising a body and a hosel, the hosel having a hosel hole having an interior surface defining a hosel joint area. wherein the shaft includes a shaft tip, a shaft rear end, and a shaft outer surface, the hosel hole receives the shaft tip forming a head-shaft connection, and the shaft has a shaft rear end. defining a longitudinal axis extending from a geometric center of the shaft to a geometric center of the shaft tip, the shaft outer surface defining a shaft bonding area and an effective bonding area near the shaft tip; , a portion of the shaft outer surface that is inserted into the hosel hole, the effective bonding area is a portion of the shaft outer surface that contacts the hosel bonding area, and the effective bonding area includes a plurality of microgrooves. The plurality of microgrooves are recessed into the shaft from the outer surface of the shaft through a plurality of sidewalls, the plurality of sidewalls increase the effective bonding area, and the plurality of microgrooves are arranged in a line. a first plurality of microgrooves extending in a first direction and a second plurality of microgrooves extending in a second direction; a plurality of interconnected microgrooves extending circumferentially around the shaft, the grip being coupled to a rear end of the shaft.

Clause 2: The golf club of Clause 1, wherein the first plurality of microgrooves and the second plurality of microgrooves are integrally formed with the shaft.

Clause 3: The first plurality of microgrooves and the second plurality of microgrooves define individual microgroove depths, and the individual microgroove depths are less than 0.0038 inch. 1. The golf club according to 1.

Clause 4: the first plurality of microgrooves and the second plurality of microgrooves define a total microgroove depth, the total microgroove depth being measured along the longitudinal axis; The golf according to clause 1, wherein the total microgroove depth is the depth of the tip of the shaft that includes microgrooves, and the total microgroove depth is between 1.00 inches and 3.00 inches. ·club.

Clause 5: The golf club of clause 1, wherein the first plurality of microgrooves and the second plurality of microgrooves cover 50% to 90% of the shaft joint area.

Clause 6: Each of the plurality of microgrooves includes a floor, the floor is perpendicular to the plurality of sidewalls of the individual microgroove, and the individual microgroove is U-shaped in cross-section. The golf club described in Article 1.

Clause 7: Each microgroove of the first plurality of microgrooves extends in the first direction and is parallel to an adjacent microgroove of the first plurality of microgrooves; The golf club of clause 1, wherein each microgroove of the microgrooves extends in the second direction and is parallel to an adjacent microgroove of the second plurality of microgrooves.

Clause 8: The golf club of Clause 7, wherein the first direction and the second direction are oblique to the longitudinal axis.

Clause 9: The golf club of Clause 8, wherein the first plurality of microgrooves and the second plurality of microgrooves provide resistance to normal forces and torsional forces.

Clause 10: The golf club of Clause 7, wherein the first direction is perpendicular to the longitudinal axis and the second direction is parallel to the longitudinal axis.

Clause 11: A golf club comprising a club head, a shaft, and a grip, the club head comprising a body and a hosel, the hosel comprising a hosel hole having an inner surface defining a hosel joint area; the shaft has a shaft tip, a shaft rear end, and a shaft outer surface, the hosel hole receives the shaft tip forming a head-shaft connection, and the shaft has a shaft rear end geometry. defining a longitudinal axis extending from the center to the geometric center of the shaft tip, the shaft outer surface defining a shaft bonding area and an effective bonding area proximate the shaft tip; a portion of the shaft outer surface that is inserted into a hosel hole, the effective bonding area is a portion of the shaft outer surface that contacts the hosel bonding area, and the effective bonding area includes a plurality of microgrooves; The plurality of microgrooves are recessed into the shaft from the outer surface of the shaft through a plurality of sidewalls, the plurality of sidewalls increase the effective bonding area, and the plurality of microgrooves are formed into a predetermined shape. a golf club, wherein the plurality of microgrooves are not interconnected and extend circumferentially around the shaft, and the grip is coupled to a rear end of the shaft.

Clause 12: The golf club according to Clause 11, wherein the plurality of microgrooves are integrally formed with the shaft.

Clause 13:
12. The golf club of clause 11, wherein the plurality of microgrooves define individual microgroove depths, and wherein the individual microgroove depths are less than 0.0038 inch.

Clause 14: the plurality of microgrooves define a total microgroove depth, the total microgroove depth is measured along the longitudinal axis, and the total microgroove depth is determined by 12. The golf club of clause 11, wherein the total microgroove depth is between 1.00 inches and 3.00 inches.

Clause 15: The golf club of Clause 11, wherein the plurality of microgrooves cover 50% to 90% of the shaft joining area.

Clause 16: Each of the plurality of microgrooves includes a floor, the floor is perpendicular to the plurality of sidewalls of the individual microgroove, and the individual microgroove is U-shaped in cross-section. The golf club described in Article 11.

Clause 17: The golf club of Clause 11, wherein each microgroove has a shape selected from the group consisting of a triangle, a line, a square, a rectangle, or a spiral.

Clause 18: The golf club of clause 17, wherein each of the microgrooves has the same shape.

Clause 19: The golf club of Clause 17, wherein each of the microgrooves comprises a different shape.

Clause 20: The golf club of Clause 11, wherein the plurality of microgrooves provide resistance to normal and torsional forces.

Clause 21: A golf club comprising a club head, a shaft, a grip, and a ferrule, the club head comprising a body and a hosel comprising a hosel rim, a hosel base, and a hosel inner surface, the hosel comprising a hosel rim, a hosel base, and a hosel inner surface. the inner surface defines a hosel hole extending from the hosel rim to the hosel base, the shaft has a top end received within the grip, a bottom end received within the hosel hole, and a diameter, and the ferrule defines a hosel hole extending from the hosel rim to the hosel base; , a bottom edge, a ledge, an outer surface, an inner surface, a centering region, and a tapered region, the ledge defining a boundary between the tapered region and the centering region, and the centering region connecting the ledge and the bottom edge. a lower portion of the ferrule defined between the ferrule, the centering region being received within the hosel bore, and a tapered region being an upper portion of the ferrule defined between the ledge and the top edge; a golf club comprising an internal weight, the internal weight comprising a cylindrical tube having a top periphery, a bottom periphery, an inner surface, an outer surface, and a gap.

Clause 22: The golf club of Clause 21, wherein the internal weight is integrally formed with the tapered region.

Clause 23: The golf club of Clause 21, wherein the inner surface of the internal weight forms part of the inner surface of the ferrule.

Clause 24: The golf club of Clause 21, wherein the gap defines an opening extending from the top periphery to the bottom periphery.

Clause 25: The golf club of Clause 24, wherein the gap comprises a gap width between 0.01 inch and 0.5 inch.

Clause 26: The golf club of Clause 21, wherein the internal weight has a height of between 0.5 inches and 0.7 inches.

Clause 27: The golf club of Clause 21, wherein the internal weight has a thickness of between 0.01 inch and 0.09 inch.

Clause 28: The golf club of claim 27, wherein the thickness of the internal weight increases from the top periphery to the bottom periphery.

Clause 29: The golf club of Clause 21, wherein the centering region comprises a plurality of windows to increase epoxy flow around the shaft to form a stronger bond between the shaft and hosel.

Clause 30: The centering region further comprises a plurality of ribs, the plurality of ribs are equally spaced throughout the centering region, and the plurality of ribs are in the hosel hole for centering the shaft within the hosel. 22. The golf club according to clause 21, wherein the golf club applies equal pressure to the golf club.

Clause 31: A golf club comprising a club head, a shaft, a grip, and a ferrule, the club head comprising a body and a hosel having a hosel rim, a hosel base, and a hosel inner surface, the hosel comprising a hosel rim, a hosel base, and a hosel inner surface. the inner surface defines a hosel hole extending from the hosel rim to the hosel base, the shaft has a top end received within the grip, a bottom end received within the hosel hole, and a diameter, and the ferrule defines a hosel hole extending from the hosel rim to the hosel base; , a bottom edge, a ledge, a centering region, and a tapered region, the ledge defining a boundary between the tapered region and the centering region, and a centering region defined between the ledge and the bottom edge. a lower portion of the ferrule with a centering region received within the hosel bore and a tapered region defined between the ledge and the top edge; or a golf club comprising a plurality of weighted rings, each of the one or more weighted rings comprising a cylindrical tube having a top periphery, a bottom periphery, an inner surface, and an outer surface.

Clause 32: The golf club of Clause 31, wherein the one or more weighted rings are integrally formed with the tapered region.

Clause 33: The golf club of Clause 31, wherein the outer surface of each of the one or more weighted rings forms part of the outer surface of the ferrule.

Clause 34: The golf club of Clause 31, wherein the one or more weighted rings can be one ring, two rings, three rings, four rings, or five rings.

Clause 35: The golf club of Clause 31, wherein the one or more weighted rings have a height of 0.1 inch to 0.5 inch.

Clause 36: The golf club of Clause 35, wherein each of the one or more weighted rings has the same height.

Clause 37: The golf club of Clause 35, wherein each of the one or more weighted rings has a different height.

Clause 38: The golf club of Clause 31, wherein the one or more weighted rings have a thickness of 0.01 inches to 0.08 inches.

Clause 39: Clause 31, wherein the one or more weighted rings are formed from a metallic material selected from the group consisting of stainless steel, tungsten, a tungsten-tenite propionate mixture, or a stainless steel-tenite propionate mixture. Golf clubs listed in .

Clause 40: The golf club of Clause 31, wherein the one or more weighted rings include a total mass of 1 gram to 10 grams.

Clause 41: A golf club comprising a club head, a shaft, and a grip, the club head comprising a body and a hosel having a hole, the shaft having a top end, a bottom end, a hot melt weight. , and a cap having a top end proximate the grip and a bottom end proximate the club head opposite the top end, the bottom end being received within the hosel and having a hot melt weight. , formed inside the shaft near the bottom end, and having a cap secured to the bottom end.

Replacing one or more claimed elements constitutes a reconstruction rather than a repair. Additionally, benefits, other advantages, and solutions to problems have been described with respect to particular embodiments. However, any benefit, advantage, solution to a problem, and any element that can give rise to or make the benefit, advantage, solution, or element more pronounced is included in the claim. It should not be construed as a critical, necessary, or essential feature or element of any or all claims unless explicitly described as such.

Further, the embodiments and limitations disclosed herein may not be applicable if the embodiments and/or limitations (1) are not expressly claimed in a claim and (2) are not explicitly claimed in a claim under the doctrine of equivalents. Equivalents or potential equivalents of express elements and/or limitations are not provided to the public under the doctrine of Dedication.

Claims (20)

A golf club comprising a club head, a shaft, and a grip, the golf club comprising:
the club head includes a body and a hosel;
the hosel includes a hosel bore having an inner surface defining a hosel mating area;
The shaft includes a shaft tip, a shaft rear end, and a shaft outer surface,
the hosel hole receives the shaft tip forming a head-shaft connection;
the shaft defines a longitudinal axis extending from a geometric center of the shaft rear end to a geometric center of the shaft distal end;
The shaft outer surface defines a shaft bonding area and an effective bonding area near the shaft tip, the shaft bonding area being the portion of the shaft outer surface that is inserted into the hosel hole, and the shaft bonding area defining the effective bonding area. a region of the shaft outer surface that contacts the hosel joint region;
the effective bonding region includes a plurality of microgrooves,
the plurality of microgrooves are recessed into the shaft from the outer surface of the shaft through a plurality of sidewalls, the plurality of sidewalls increasing the effective bonding area;
the plurality of microgrooves are formed as lines and define a first plurality of microgrooves extending in a first direction and a second plurality of microgrooves extending in a second direction;
the first plurality of microgrooves and the second plurality of microgrooves are interconnected and extend circumferentially around the shaft;
the grip is connected to the rear end of the shaft;
Golf club. The golf club of claim 1, wherein the first plurality of microgrooves and the second plurality of microgrooves are integrally formed with the shaft. the first plurality of microgrooves and the second plurality of microgrooves define individual microgroove depths;
the individual microgroove depth is less than 0.0038 inch;
A golf club according to claim 1. the first plurality of microgrooves and the second plurality of microgrooves define a total microgroove depth;
the total microgroove depth is measured along the longitudinal axis, the total microgroove depth is the depth of the shaft tip comprising microgrooves, and the total microgroove depth is 1. between 00 inches and 3.00 inches,
A golf club according to claim 1. The golf club of claim 1, wherein the first plurality of microgrooves and the second plurality of microgrooves cover 50% to 90% of the shaft joint area. 1 . Each of the plurality of microgrooves includes a floor, the floor is perpendicular to the plurality of sidewalls of the individual microgroove, and the individual microgroove is U-shaped in cross-section. Golf clubs listed in . each microgroove of the first plurality of microgrooves extends in the first direction and is parallel to an adjacent microgroove of the first plurality of microgrooves; 2. The golf club of claim 1, wherein each microgroove extends in the second direction and is parallel to adjacent microgrooves of the second plurality of microgrooves. 8. The golf club of claim 7, wherein the first direction and the second direction are oblique to the longitudinal axis. 9. The golf club of claim 8, wherein the first plurality of microgrooves and the second plurality of microgrooves provide resistance to normal and torsional forces. 8. The golf club of claim 7, wherein the first direction is perpendicular to the longitudinal axis and the second direction is parallel to the longitudinal axis. A golf club comprising a club head, a shaft, and a grip,
the club head includes a body and a hosel;
the hosel includes a hosel bore having an inner surface defining a hosel mating area;
The shaft includes a shaft tip, a shaft rear end, and a shaft outer surface,
the hosel hole receives the shaft tip forming a head-shaft connection;
the shaft defines a longitudinal axis extending from a geometric center of the shaft rear end to a geometric center of the shaft distal end;
The shaft outer surface defines a shaft bonding area and an effective bonding area near the shaft tip, the shaft bonding area being the portion of the shaft outer surface that is inserted into the hosel hole, and the shaft bonding area defining the effective bonding area. a region of the shaft outer surface that contacts the hosel joint region;
the effective bonding region includes a plurality of microgrooves,
the plurality of microgrooves are recessed into the shaft from the outer surface of the shaft through a plurality of sidewalls, the plurality of sidewalls increasing the effective bonding area;
the plurality of microgrooves are formed in a predetermined shape,
the plurality of microgrooves are not interconnected and extend circumferentially around the shaft;
the grip is connected to the rear end of the shaft;
Golf club. 12. The golf club of claim 11, wherein the plurality of microgrooves are integrally formed with the shaft. the plurality of microgrooves define individual microgroove depths;
the individual microgroove depth is less than 0.0038 inch;
A golf club according to claim 11. the plurality of microgrooves define a total microgroove depth;
the total microgroove depth is measured along the longitudinal axis, the total microgroove depth is the depth of the shaft tip comprising microgrooves, and the total microgroove depth is 1. between 00 inches and 3.00 inches,
A golf club according to claim 11. The golf club of claim 11, wherein the plurality of microgrooves cover 50% to 90% of the shaft joint area. 12. Each of the plurality of microgrooves includes a floor, the floor is perpendicular to the plurality of sidewalls of the individual microgroove, and the individual microgroove is U-shaped in cross-section. Golf clubs listed in . 12. The golf club of claim 11, wherein each microgroove comprises a shape selected from the group consisting of a triangle, a line, a square, a rectangle, or a spiral. 18. The golf club of claim 17, wherein each of the microgrooves comprises the same shape. 18. The golf club of claim 17, wherein each of the microgrooves comprises a different shape. 12. The golf club of claim 11, wherein the plurality of microgrooves provide resistance to normal and torsional forces.

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