Golf Club Head with Flexible Sole

This is a continuation of U.S. patent application Ser. No. 18/454,003, filed on Aug. 22, 2023, and issued as U.S. patent Ser. No. 12/343,603 which is a continuation of Ser. No. 17/088,440, filed on Nov. 3, 2020, and issued as U.S. Pat. No. 11,731,011 on Aug. 22, 2023, which is a continuation of U.S. patent application Ser. No. 16/455,599, filed on Jun. 27, 2019, and issued as U.S. Pat. No. 10,821,336 on Nov. 3, 2020, which claims the benefit of U.S. Provisional Patent Appl. No. 62/861,247, filed on Jun. 13, 2019, U.S. Provisional Patent Appl. No. 62/856,637, filed on Jun. 3, 2019, and U.S. Provisional Patent Appl. No. 62/690,858, filed on Jun. 27, 2018, the contents of which are incorporated fully herein by reference.

This disclosure relates generally to golf clubs and relates more particularly to golf club heads with flexible soles.

Metalwood golf club heads typically include a high strength metal faceplate attached to a hollow metal club body. When a metalwood club head impacts a golf ball, the travel distance of the ball is largely a function of the kinetic energy imparted from the club head to the ball. During impact, some of the energy is lost as a result of the collision. One measure of energy transfer from the club head to the golf ball is the Coefficient of Restitution (“COR”). Most of the energy is lost as a result of high stresses and deformations of the golf ball, as opposed to the relatively small deformations of the club head. To reduce the amount of energy lost during impact, and thus increase the energy transfer efficiency, the stresses and rate of deformation experienced by the golf ball during impact must be reduced.

One way to accomplish this is to allow more deformation of the club head during impact. For example, this can be achieved by increasing the flexure of the faceplate. Typical means of increasing faceplate flexure include uniform faceplate thinning, varying a thickness of the faceplate, providing ribbed stiffeners on the faceplate, utilizing lighter materials such as titanium, and providing forged, stamped, or machined metal faceplates as opposed to cast faceplates.

Another way to increase deformation of the club head during impact is to increase the deformation of the club head body. This can be achieved by altering the geometry of the club head body to have a radius of curvature between the front and back regions. Some prior art club heads have accomplished this by providing sole regions having increased camber outward between the front and the back of the club head. The increased camber outward distributes stresses across a broader area in the sole region, allowing the thickness of the sole region to be reduced to promote larger deformations. However, these prior art sole regions “bow out” toward the ground and away from a centerline of the club head. This results in a strikeface that resides higher off the ground at an address position, making it more difficult to achieve desirable contact at impact. There is a need in the art for a golf club head with significant camber in the sole that does not bow outward towards the ground at an address position, or other structures that provide optimal deformation of the golf club.

For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the golf clubs and their methods of manufacture. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the golf clubs and their methods of manufacture. The same reference numerals in different figures denote the same elements.

Described herein is a metalwood golf club head including a body having a reverse camber sole. Specifically, the sole of the club head includes an indented region, and the indented region includes a region of reversed concavity as compared to a concavity of remaining regions of the sole. The reverse camber sole follows a more tightly curved profile between a front end of the club head and a back end of the club head, as compared to prior art metalwood club heads. This promotes greater deflection in the sole of the body as the club head impacts a golf ball. The relatively greater deflection of the club body can yield higher internal energy of the club head as compared to prior art metalwood golf clubs. The higher the internal energy of the club head translates to farther traveling golf shots. Additionally, the relatively greater deflection of the sole during impact can lead to a reduction in ball spin rate experienced by the golf ball upon impact with the club head.

In some embodiments, the club head described herein can also include one or more internal beams attached to the sole at a first end and at a second end and extending through an internal cavity of the golf club head between the first and second ends. The first end of each beam is attached to the sole at a location proximate the front end of the golf club head, and the second end of each beam is attached to the sole at or near the indented region. The internal beams further promote bending in the sole during impact with the golf ball, while reinforcing the sole to prevent failure.

The terms “first,” “second,” “third,” “fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of golf clubs and methods of manufacture described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “contain,” “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “side,” “under,” “over,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of golf clubs and methods of manufacture described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. The term “coupled,” as used herein, is defined as directly or indirectly connected in a physical, mechanical, or other manner.

Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways.

illustrate an embodiment of a golf club headhaving a flexible sole. The soleis designed to camber inwards (away from a ground plane) and thereby increase the flexibility of the golf club headupon impact with a golf ball. The increase in provides greater internal energy generated by the golf club head. This increase in internal energy increase the ball speed of a golf ball struck by golf club head. Increased ball speed directly translates late to farther traveling golf shots. The inward camber sole provides a 5-10 yards greater distance over a golf club head without the inward camber sole. The golf club headcan further comprise one or more stiffening beamsto moderate and control the flexibility of the golf club head.

illustrate a golf club headhaving a bodyand a strikeface. The bodyof the club headincludes a front end, a back endopposite the front end, a crown, the soleopposite the crown, a heel, and a toeopposite the heel. The soleof the golf club headcomprises a ground plane, wherein the ground planeis tangent to the solewhen the golf club headis at an address position to strike a golf ball.

The club headis a hollow body club head. The golf club headcomprises a bodyand a strikeface. The bodyand strikefacedefine an internal cavity() of the golf club head. In the illustrated embodiment, the bodyalso defines the crown, the sole, the heel, the toe, the back end, a perimeter portion() of the front endof the club head. These features can also define a hollow body. The perimeter portionof the bodyfurther defines an openingat the front endof the club head, and the strikefaceis coupled to the perimeter portionto fill the opening, thereby forming the club head. In other embodiments (not shown), the strikefacecan extend over the entire front endof the club head and can include a return portion extending over at least one of the crown, the sole, the heel, and the toe. In these embodiments, the return portion of the strikefaceis coupled to the bodyto form the club head.

As shown in, the club headfurther comprises a hosel structureand a hosel axisextending centrally along a bore of the hosel structure. The hosel structurecan be coupled to an end of a golf shaft (not shown). The golf shaft can be secured to the hosel structureat a plurality of angles relative to the hosel axis. There can be other examples, however, where the shaft can be non-adjustably secured to the hosel structure.

The club headdefines a depth, a length, and a height. Referring to, the depthof the club headcan be measured as the furthest extent of the club headfrom the front end, to the back end, in a direction parallel to the Z axis.

The lengthof the club headcan be measured as the furthest extent of the club headfrom the heelto the toe, in a direction parallel to the X axis, when viewed from the front view (). In many embodiments, the lengthof the club headcan be measured according to a golf governing body such as the United States Golf Association (USGA). For example, the lengthof the club headcan be determined in accordance with the USGA's Procedure for Measuring the Club Head Size of Wood Clubs (USGA-TPX3003, Rev. 2.1, Apr. 9, 2019).

The heightof the club headcan be measured as the furthest extent of the club headfrom the crownto the sole, in a direction parallel to the Y axis, when viewed from the front view (). In many embodiments, the heightof the club headcan be measured according to a golf governing body such as the United States Golf Association (USGA). For example, the heightof the club headcan be determined in accordance with the USGA's Procedure for Measuring the Club Head Size of Wood Clubs.

In many embodiments, a volume (V) of the club headis greater than approximately 150 cc, greater than approximately 160 cc, greater than approximately 170 cc, greater than approximately 170 cc, greater than approximately 180 cc, greater than approximately 190 cc, or greater than approximately 195 cc. In some embodiments, the volume (V) of the club head can be approximately 150 cc-198 cc, 160 cc-198 cc, 170 cc-198 cc, approximately 180 cc-198 cc, or approximately 190 cc-199 cc.

Further, in many embodiments, the volume of the club headis greater than approximately 400 cc, greater than approximately 425 cc, greater than approximately 450 cc, greater than approximately 475 cc, greater than approximately 500 cc, greater than approximately 525 cc, greater than approximately 550 cc, greater than approximately 575 cc, greater than approximately 600 cc, greater than approximately 625 cc, greater than approximately 650 cc, greater than approximately 675 cc, or greater than approximately 700 cc. In some embodiments, the volume of the club headcan be approximately 400cc-600cc, 425cc-500cc, approximately 500cc-600cc, approximately 500cc-650cc, approximately 550cc-700cc, approximately 600cc-650cc, approximately 600cc-700cc, or approximately 600cc-800cc.

With continued reference to, the strikefaceof the club headdefines a centerpoint or geometric center. In some embodiments, the geometric centercan be located at the geometric centerpoint of a strikeface perimeter, and at a midpoint of a face height. In the same or other examples, the geometric centeralso can be centered with respect to an engineered impact zone, which can be defined by a region of grooveson the strikeface. As another approach, the geometric centerof the strikefacecan be in accordance with the definition of a golf governing body such as the United States Golf Association (USGA). For example, the geometric centerof the strikefacecan be determined in accordance with Section 2.1 of the USGA's Procedure for Measuring the Flexibility of a Golf Clubhead (USGA-TPX3004, Rev. 2.0, Apr. 9, 2019).

With reference to, the club headfurther defines a loft planetangent to the geometric centerof the strikeface. The face heightcan be measured parallel to loft planebetween a top end of the strikeface perimeternear the crownand a bottom end of the strikeface perimeternear the sole.

The geometric centerof the strikefacefurther defines a coordinate system of golf club headhas an origin located at the geometric centerof the strikeface. The coordinate system further comprises an X axis, a Y axis, and a Z axis. The X axisextends through the geometric centerof the strikefacein a direction from the heelto the toeof the club head. The Y axisextends through the geometric centerof the strikefacein a direction from the crownto the soleof the club headand is perpendicular to the X axis. The Z axisextends through the geometric centerof the strikefacein a direction from the front endto the back endof the club headand is perpendicular to the X axisas well as the Y axis.

The coordinate system defines an XY planeextending through the X axisand the Y axis; an XZ planeextending through the X axisand the Z axis; and a YZ planeextending through the Y axisand the Z axis. The XY plane, the XZ plane, and the YZ planeare all perpendicular to one another and intersect at the origin of the coordinate system located at the geometric centerof the strikeface. The XY planeextends parallel to the hosel axisand is positioned at an angle corresponding to a loft angleof the club headfrom the loft plane. Further, the X axisis positioned at an approximately 60 degree angle to the hosel axiswhen viewed from a direction perpendicular to the XY plane(i.e., as viewed in). In other embodiments, the X axiscan be positioned at a 45-70 degree angle to the hosel axiswhen viewed from a direction perpendicular to the XY plane.

In these or other embodiments, the club headcan be viewed from a front view (e.g., as in) when the strikefaceis viewed from a direction perpendicular to the XY plane. Further, in these or other embodiments, the club headcan be viewed from a side view or side cross-sectional view (e.g., as in) when the heelis viewed from a direction perpendicular to the YZ plane.

As shown in, the club headfurther comprises a head center of gravity (CG)and a head depth planeextending through the geometric centerof the strikeface, perpendicular to the loft plane, in a direction from the heelto the toeof the club head. In many embodiments, the head CGis located at a head CG depth from the XY plane, measured in a direction perpendicular to the XY plane. In some embodiments, the head CGcan be located at a head CG depthfrom the loft plane, measured in a direction perpendicular to the loft plane. The head CGis further located at a head CG heightfrom the head depth plane, measured in a direction perpendicular to the head depth plane. Further, the head CG heightis measured as the offset distance from the head depth planein a direction perpendicular to the head depth planetoward the crownor toward the sole. In many embodiments, the head CG heightis positive when the head CGis located above the head depth plane(i.e., between the head depth planeand the crown), and the head CG heightis negative when the head CGis located below the head depth plane(i.e., between the head depth planeand the sole). In some embodiments, the absolute value of the head CG heightcan describe a head CGpositioned above or below the head depth plane(i.e., between the head depth planeand the crownor between the head depth planeand the sole). In many embodiments, the head CGis strategically positioned toward the soleand back endof the club head.

The head CGdefines an origin of a coordinate system having an X′ axis, a Y′ axis, and a Z′ axis. The Y′ axisextends through the head CGfrom the crownto the sole, parallel to the hosel axiswhen viewed from the side view, and at a 30 degree angle from the hosel axiswhen viewed from the front view (i.e., as viewed in). The X′ axisextends through the head CGfrom the heelto the toeand perpendicular to the Y′ axiswhen viewed from a front view and parallel to the XY plane. The Z′ axisextends through the head CGfrom the front endto the back endand perpendicular to the X′ axisand the Y′ axis. In many embodiments, the X′ axisextends through the head CGfrom the heelto the toe, and parallel to the X axis. The Y′ axisextends through the head CGfrom the crownto the soleparallel to the Y axis. The Z′ axisextends through the head CGfrom the front endto the back endand parallel to the Z axis.

While the above examples may be described in connection with a wood-type golf club, the apparatus, methods, and articles of manufacture described herein may be applicable to a variety of types of golf clubs including drivers, fairway woods, hybrids, crossovers, or any hollow body type golf clubs.

The club headfurther comprises a loft angle (not shown) measured as the angle between the loft planeand the ground plane. In many embodiments, the loft angle ranges between approximately 7 degrees and 40 degrees. In some embodiments, the loft angle of the club headis less than approximately 16 degrees, less than approximately 15 degrees, less than approximately 14 degrees, less than approximately 13 degrees, less than approximately 12 degrees, less than approximately 11 degrees, or less than approximately 10 degrees.

In many embodiments, the loft angle of the club headis less than approximately 35 degrees, less than approximately 34 degrees, less than approximately 33 degrees, less than approximately 32 degrees, less than approximately 31 degrees, or less than approximately 30 degrees. Further, in many embodiments, the loft angle of the club headis greater than approximately 12 degrees, greater than approximately 13 degrees, greater than approximately 14 degrees, greater than approximately 15 degrees, greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, or greater than approximately 20 degrees. For example, in some embodiments, the loft angle of the club headcan be between 12 degrees and 35 degrees, between 15 degrees and 35 degrees, between 20 degrees and 35 degrees, or between 12 degrees and 30 degrees.

In many embodiments, the loft angle of the club headis less than approximately 40 degrees, less than approximately 39 degrees, less than approximately 38 degrees, less than approximately 37 degrees, less than approximately 36 degrees, less than approximately 35 degrees, less than approximately 34 degrees, less than approximately 33 degrees, less than approximately 32 degrees, less than approximately 31 degrees, or less than approximately 30 degrees. Further, in many embodiments, the loft angle of the club headis greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, greater than approximately 20 degrees, greater than approximately 21 degrees, greater than approximately 22 degrees, greater than approximately 23 degrees, greater than approximately 24 degrees, or greater than approximately 25 degrees.

The strikefaceof the club headis formed from a first material. In many embodiments, the first material can be a metal alloy, such as a titanium alloy (e.g., Ti 7-4, Ti 6-4, T-9S, Ti SSAT2041, Ti SP700, Ti 15-0-3, Ti 15-5-3, Ti 3-8-6-4-4, Ti 10-2-3, Ti 15-3-3-3, Ti-6-6-2, Ti-185, HST-180, etc., or any combination thereof), a steel alloy (e.g., C300 steel, C350 steel, 455 steel, 431 steel, 475 steel, 565 steel, 17-4 stainless steel, maraging steel, Ni—Co—Cr steel alloy, etc.), an aluminum alloy, or any other metal or metal alloy. In other embodiments, the first material can be another material, such as a composite, plastic, thermoplastic composite, or any other suitable material or combination of materials.

The bodyof the club headis formed from a second material. In many embodiments, the second material can be a metal alloy, such as a titanium alloy (e.g., Ti 7-4, Ti 6-4, T-9S, Ti SSAT2041, Ti SP700, Ti 15-0-3, Ti 15-5-3, Ti 3-8-6-4-4, Ti 10-2-3, Ti 15-3-3-3, Ti-6-6-2, Ti-185, etc., or any combination thereof), a steel alloy (e.g., C300 steel, C350 steel, 455 steel, 431 steel, 475 steel, 565 steel, 17-4 stainless steel, maraging steel, Ni—Co—Cr steel alloy, etc.), an aluminum alloy, or any other metal or metal alloy. In other embodiments, the second material can be another material, such as a composite, plastic, or any other suitable material or combination of materials. In the illustrated embodiment, the second material differs from the first material. In other embodiments, the first and second materials can be the same.

With reference to, the soleof golf club headfurther includes an indent or indented regionwhere the soleveers inward in a direction toward the internal cavity(). With respect to the XZ plane(), the indented regionincludes a reverse camber regionthat is convex relative to the XZ plane. Typical prior art metalwoods include sole profiles that are only concave with respect to a comparable XZ plane. Accordingly, typical prior art metalwoods include sole profiles having relatively large radii of curvature between the front end and the back end (i.e., radii of curvature of around 22-25 inches). In contrast, the indented regionof the golf club headallows the soleto follow a much more tightly curved profile between the front endand the back end. For example, in some embodiments of the club head, when viewed from a side cross-sectional view taken along the YZ plane(e.g., as viewed in), no portion of the soleintersected by the YZ planeincludes a radius of curvature greater than 10 inches between the front endand the back end.

Moreover, in the illustrated embodiment of the club head, no portion of the soleincludes a radius of curvature greater than 6 inches when viewed from the side cross-sectional view taken along the YZ plane. By implementing the indented regioninto the sole, and thereby achieving relatively smaller radii of curvature of the solebetween the front and back endsand, the club head bodyexperiences greater deformations in the soleduring impact with a golf ball. This results in an increase in the flexure of the golf club headand more efficient energy transfer from the club headto the ball during impact. The curvature of the solewill be described in greater detail below.

With reference to, the club headincludes a face-sole transition boundary() where the front endtransitions to the sole. The face-sole transition boundaryextends between the front endand the solefrom near the heelto near the toe. A face-sole transition profileis defined where the face-sole transition boundaryis intersected by the YZ plane. That is, the face-sole transition profileis the linear portion of the face-sole transition boundarythat is intersected by the YZ plane, visible when viewed from a side cross sectional view taken along the YZ plane(e.g., as viewed in).

The face-sole transition profilefollows a face-sole transition radius of curvature R1. The face-sole transition profileextends from a strikeface transition point, where a contour of the strikefacedeparts from a roll radius of the strikeface, to a sole transition point, at which point the curvature of the soledeparts from the face-sole transition radius of curvature R1. The sole transition pointis defined by an intersection of the strikefaceand the sole. In some embodiments, the face-sole transition radius of curvature R1 comprises a constant radius of curvature extending from the strikeface transition pointto the sole transition point.

In some embodiments, the face-sole transition radius of curvature R1 can range from approximately 0.10 to 0.50 inches. For example, the face-sole transition radius of curvature R1 can be less than approximately 0.5 inches, less than approximately 0.475 inches, less than approximately 0.45 inches, less than approximately 0.425 inches, or less than approximately 0.40 inches. For further example, the face-sole transition radius of curvature R1 can be approximately 0.10 inches, 0.15 inches, 0.20 inches, 0.25 inches, 0.30 inches, 0.35 inches, 0.40 inches, 0.45 inches, or 0.50 inches.

With continued reference to, the soledefines an exterior sole surface() extending from the front endto the back end, and from the heelto the toe. A sole curvature profileof the club headis defined as a linear extent of the sole surfaceintersected by the YZ planeand extending from the sole transition pointto the back end. The sole curvature profileincludes a first concave section, a convex section, and a second concave section. The first concave sectionextends from the sole transition pointto a first inflection pointand is concave relative to the XZ plane(convex relative to the ground plane). The first inflection pointis defined as a first point along the sole curvature profilewhere, when following the sole curvature profilefrom the front endtoward the back end, the sole curvature profilereverses concavity with respect to the XZ plane.

The convex sectionof the sole curvature profileextends from the first inflection pointto a second inflection pointand is convex relative to the XZ plane(concave relative to the ground plane). The second inflection pointis defined as a second point along the sole curvature profilewhere, when following the sole curvature profilefrom the front endtoward the back end, the sole curvature profilereverses concavity with respect to the XZ plane. The second concave sectionof the sole curvature profileextends from the second inflection pointto the back endand is concave relative to the XZ plane(convex relative to the ground plane).

With continued reference to, the club headfurther includes a first inflection point depthmeasured along a direction perpendicular to the loft planebetween the loft planeand the first inflection point. In many embodiments, the first inflection point depthof the club headis greater than 0.50 inches. In the illustrated embodiment, the first inflection point depthis approximately 1.50 inches. In other embodiments, the first inflection point depthof the club headis greater than 0.75 inches, greater than 1.00 inches, greater than 1.10 inches, greater than 1.20 inches, greater than 1.30 inches, greater than 1.40 inches, greater than 1.50 inches, greater than 1.60 inches, greater than 1.70 inches, greater than 1.80 inches, greater than 1.90 inches, greater than 2.00 inches, greater than 2.25 inches, or greater than 2.50 inches. For example, in some embodiments, the first inflection point depthof the club headcan be between 0.50-2.50 inches, between 1.00-2.00 inches, between 1.25-1.75 inches, between 1.35-1.65 inches, or between 1.45-1.55 inches. In some embodiments, the first inflection point depthof the club headcan be 0.50 inches, 0.75 inches, 1.0 inches, 1.25 inches, 1.50 inches, 1.75 inches, 2.00 inches, 2.25 inches, or 2.50 inches.

A first inflection point depth ratio of the club headis defined as a ratio of the first inflection point depthto the depthof the club head. In many embodiments, the first inflection point depth ratio is greater than 0.25. In other embodiments, the first inflection point depth ratio is greater than 0.30, greater than 0.31, greater than 0.32, greater than 0.33, greater than 0.34, greater than 0.35, greater than 0.36, greater than 0.37, greater than 0.38, greater than 0.39, greater than 0.40, or greater than 0.45. For example, in some embodiments, the first inflection point depth ratio of the club headcan be between 0.25-0.45, between 0.30-0.45, between 0.25-0.40, between 0.30-0.40, between 0.32-0.38, or between 0.34-0.36. In some embodiments, the first inflection point depth ratio of the club headcan be 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, or 0.45.

With continued reference to, the soleof the club headfurther defines a nadir. The nadiris located along a section of the sole curvature profilethat extends through the indented region(). Specifically, the nadiris defined as the point located on the sole curvature profilewithin the indented regionand closest to the XZ plane. In most embodiments, the nadiris located on the convex section. In other words, the nadirrepresents the lowest point of the indented regionas the indented regionextends toward the internal cavity.

The club headfurther includes a nadir height (not shown) wherein the nadir height is measured perpendicularly from the ground planeto the nadir. In many embodiments, the nadir height of the club headranges between 0.01 inches and 0.30 inches. In other embodiments, the nadir height of the club headcan range between 0.01-0.05 inches, 0.05-0.10 inches, 0.10-0.15 inches, 0.15-0.20 inches, 0.20-0.25 inches, or 0.25-0.30 inches. In other embodiments, the nadir height can be 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, 0.11 inch, 0.12 inch, 0.13 inch, 0.14 inch, 0.15 inch, 0.16 inch, 0.17 inch, 0.18 inch, 0.19 inch, 0.20 inch, 0.21 inch, 0.22 inch, 0.23 inch, 0.24 inch, 0.25 inch, 0.26 inch, 0.27 inch, 0.28 inch, 0.29 inch, or 0.30 inch.

The club headfurther includes a nadir depthmeasured along a direction perpendicular to the loft planebetween the loft planeand the nadir. In many embodiments, the nadir depthof the club headis greater than 1.5 inches. In other embodiments, the nadir depthof the club headis greater than 1.6 inches, greater than 1.7 inches, greater than 1.8 inches, greater than 1.9 inches, greater than 2.0 inches, greater than 2.1 inches, greater than 2.2 inches, greater than 2.3 inches, greater than 2.4 inches, or greater than 2.5 inches. For example, in some embodiments, the nadir depthof the club headcan be between 1.5-3.0 inches, between 1.5-2.5 inches, between 2.0-3.0 inches, between 2.0-2.5 inches, or between 2.5-3.0 inches.

A nadir depth ratio of the club headis defined as a ratio of the nadir depthto the depthof the club head. In many embodiments, the nadir depth ratio is greater than 0.35. In other embodiments, the nadir depth ratio is greater than 0.40, greater than 0.45, greater than 0.46, greater than 0.47, greater than 0.48, greater than 0.49, greater than 0.50, greater than 0.51, greater than 0.52, greater than 0.53, greater than 0.54, greater than 0.55, or greater than 0.60. For example, in some embodiments, the nadir depth ratio B of the club headcan be between 0.40-0.60, between 0.45-0.60, between 0.40-0.55, between 0.45-0.55, between 0.47-0.53, or between 0.49-0.51.

The sole curvature profileof the club headcan also be described in terms of the radii of curvature along each of various sections of the sole curvature profilebetween the front endand the back end. With reference to, the first concave sectionof the sole curvature profileis divided into a first curvature sectionhaving a first section radius of curvature R2, and a second curvature sectionhaving a second section radius of curvature R3. The first curvature sectionextends from the sole transition pointto a first concave section transition point, defined as a point along the sole curvature profilewhere the first section radius of curvature R2 transitions to the second section radius of curvature R3. The second curvature sectionextends from the first concave section transition pointto the first inflection point, which divides the second curvature sectionfrom the convex section. The convex sectionof the sole curvature profileincludes a convex section radius of curvature R4. Finally, the second concave sectionincludes a second concave section radius of curvature R5.

In some embodiments, the first section radius of curvature R2 can range from approximately 1.00 to 3.50 inches. In the illustrated embodiment, the first section radius of curvature R2 is approximately 1.75 inches. In other embodiments, the first section radius of curvature R2 can be less than 3.00 inches, less than 2.50 inches, less than 2.25 inches, less than 2.00 inches, or less than 1.75 inches. For example, the first section radius of curvature R2 may be approximately 1.00 inches, 1.25 inches, 1.5 inches, 1.75 inches, 2.00 inches, 2.25 inches, or 2.50 inches.

In some embodiments, the second section radius of curvature R3 can range from approximately 1.0 to 10.0 inches. In one embodiment, the second section radius of curvature R3 is approximately 6.0 inches. In other embodiments, the second section radius of curvature R3 can be less than 9.0 inches, less than 8.0 inches, less than 7.0 inches, less than 6.0 inches, less than 5.0 inches, less than 4.0 inches, less than 3.0 inches, or less than 2.0 inches. For example, the second section radius of curvature R3 may be approximately 3.0 inches, 4.0 inches, 5.0 inches, 6.0 inches, 7.0 inches, 8.0 inches, or 9.0 inches.

A nadir height ratio of the club headis defined as the ratio of the nadir height to the radius of curvature R3 of the first concave section. The nadir height is inversely related to the radius of curvature R3. As the radius of curvature R3 decreases in magnitude, the nadir height increases. As the radius of curvature R3 increases in magnitude, the nadir height decreases. In many embodiments, the nadir height ratio is less than or equal to 0.33. In other embodiments, the nadir height ratio is less than 0.30, less than 0.25, less than 0.20, less than 0.15, less than 0.10, or less than 0.05. In other embodiments, the nadir height ratio can range between 0.001-0.05, 0.05-0.10, 0.10-0.15, 0.15-0.20, 0.20-0.25, 0.25-0.30, or 0.30-0.33.