Iron-type golf club head with rear opening and insert

Abstract

Described herein are embodiments of iron-type golf club heads that include a rear opening and an insert. The insert partially or completely fills the interior cavity of the club head. The insert dampens vibrations generated in the club head at impact and provides a desirable sound and feel. The insert is formed of a low-density material, thereby providing significant damping while also creating discretionary mass.

Description

[Technical Field]

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 376,746, filed September 22, 2022, the contents of which are incorporated herein by reference in their entirety. [Background technology]

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to hollow body iron-type golf club heads, and more particularly to hollow body golf club heads having one or more rear openings and an insert. Summary of the Invention [Problem to be solved by the invention]

[0003] The design of golf club heads involves balancing performance with the sound and feel of the club head at impact, also known as "vibration response." Most iron-type club heads fail to achieve an effective combination of performance and vibration response, instead prioritizing one over the other. For example, many "blade-style" or "muscle-back" irons have excellent vibration response due to their solid body construction. However, blade-style irons and muscle-back irons lack discretionary mass available to optimize performance, resulting in poor forgiveness. In contrast, "hollow-body" or "cavity-back" irons optimize performance due to their significant discretionary mass. However, hollow-body or cavity-back irons have less than desirable vibration response due to their thin walls that vibrate significantly at impact. There is a need in the art for iron-type golf club heads that provide an improved balance between performance and vibration response. [Brief explanation of the drawings]

[0004] To facilitate further description of the embodiments, the following drawings are provided: [Figure 1]1 shows a front perspective view of a golf club head with a rear opening and an insert. [Figure 2] 2 shows a perspective view of the golf club head of FIG. 1 as seen from the rear. [Figure 3] 2 shows a front view of the golf club head of FIG. 1. [Figure 4] 2 shows the golf club head of FIG. 1 as viewed from the toe side. [Figure 5] 2 shows a rear view of the golf club head of FIG. 1 with the insert removed. [Figure 6] 2 shows a cross-sectional view of the golf club head of FIG. 1 from the toe side with the insert removed. [Figure 7] 2 shows a cross-sectional view of the golf club head of FIG. 1 as seen from the toe side. [Figure 8] 2 shows a rear view of the golf club head of FIG. 1. [Figure 9] 1 shows a cross-sectional view of a toe side of a golf club head with a rear opening, an insert, and a badge. [Figure 10] FIG. 1 shows a rear perspective view of a golf club head with a heel-side rear opening and an insert. [Figure 11] 1 shows a perspective view from the rear of a golf club head having a heel-side rear opening, a toe-side rear opening, and an insert. [Figure 12] 1 shows a rear perspective view of a golf club head having a heel-side rear opening, a toe-side rear opening, a central opening, and an insert. [Figure 13] 1 shows a rear perspective view of a golf club head with a lower rear opening and an insert. [Figure 14] 1 shows a rear perspective view of a golf club head with an upper rear opening, a lower rear opening, and an insert. [Figure 15] 15 is a cross-sectional view of the golf club head of FIG. 14 as viewed from the toe side. [Figure 16]1 shows a cross-sectional view from the toe side of a golf club head having an upper rear opening, a lower rear opening, an upper badge, a lower badge, and an insert. [Figure 17] 1 shows a rear perspective view of a golf club head with an upper rear opening, a badge, and a localized insert. [Figure 18] 18 is a cross-sectional view of the golf club head of FIG. 17 as viewed from the toe side. [Figure 19] 18 shows a cross-sectional exploded view of the golf club head of FIG. 17 from the toe side, detailing the badge and insert. [Figure 20] 1 shows a cross-sectional view from the toe side of a golf club head with a rear opening, a badge, and an insert with a lattice structure. [Figure 21] 1 shows a cross-sectional view from the toe side of a golf club head having an upper rear opening, a lower rear opening, an upper badge, a lower badge, and an insert having a lattice structure. DETAILED DESCRIPTION OF THE INVENTION

[0005] When terms such as "first," "second," "third," and "fourth" are used in the specification and claims, they are used to distinguish between similar elements and not necessarily to describe a particular sequence or chronological order. It is understood that such terms are interchangeable under appropriate circumstances, such as when the embodiments described herein are capable of operating in sequences other than those illustrated or otherwise described herein. Furthermore, "comprising," "having," and variations thereof, do not necessarily mean that a process, method, system, article, device, or apparatus comprising a list of elements is limited to those elements, but may include other elements not expressly listed or inherent in such process, method, system, article, device, or apparatus.

[0006] When terms such as "left," "right," "front," "rear," "top," "bottom," "upper," "lower," and the like are used in this specification and claims, they are used for descriptive purposes and not necessarily to describe permanent relative positions. It should be understood that such terms are interchangeable under appropriate circumstances where, for example, the inventive embodiments described herein are operable in orientations other than those illustrated or otherwise described herein.

[0007] The terms "connect," "connected," "connect," "connecting," and the like should be interpreted broadly and refer to connecting one or more elements or signals electrically, mechanically, and / or otherwise.

[0008] Illustrated are several embodiments of a golf club, which is generally understood to include a club head configured to receive a shaft, and further includes a grip secured to the shaft.

[0009] 1-7 illustrate various schematic views of an iron-type golf club head. The features described below are illustrated with respect to club head 100. For ease of explanation, the features illustrated with respect to club head 100 are applicable to various embodiments of club heads according to the present invention. Any one or more of the features described in the various embodiments below may be used in combination. Furthermore, while different embodiments are numbered differently (i.e., numbered 1xx, 2xx, 3xx, etc.), similar elements are numbered similarly between embodiments (i.e., club head 100 includes a top rail 110 and a sole 112, and club head 200 includes a top rail 210 and a sole 212).

[0010] The club head 100 may include a body 101 having a top rail 110, a sole 112 opposite the top rail 110, a heel 104, a toe 106 opposite the heel 104, a front end 108, and a rear end 111 opposite the front end 108. The body 110 may further include a rear wall 116 extending at least partially along the rear end 111 between the top rail 110 and the sole 112. The body 101 at least partially encloses an internal cavity 107. The body 110 further includes a hosel 105 configured to receive a shaft.

[0011] In some embodiments, the body material may be stainless steel, such as 17-4 stainless steel. In other embodiments, the body material may be steel or stainless steel alloy, such as 15-5 stainless steel, 431 stainless steel, 4140 steel, 4340 steel, or any other suitable material. The body material may have a modulus of 7.0 g / cm 3 ~10.0g / cm 3 In some embodiments, the body material may have a density of 7.0 g / cm 3 ~7.5g / cm 3 , 7.5~8.0g / cm 3 , 8.0~8.5g / cm 3 , 8.5~9.0g / cm 3 , 9.0~9.5g / cm 3 , or 9.5 to 10.0 g / cm 3 The density may be

[0012] As used herein, the term "striking face" refers to the front of the club head that is configured to strike a golf ball. The term "striking face" may be used interchangeably with the term "face."

[0013] As used herein, the term "striking face perimeter" may refer to the edge of the striking face. The striking face perimeter may be located along the outer edge of the striking face where the striking face ceases to be planar. Referring to FIG. 1 , the striking face perimeter includes an upper edge 118 that defines the highest point on the striking face 102. The striking face perimeter further includes a leading edge 103 that defines the lowest point on the striking face 102. The striking face perimeter is the outermost edge of the striking face 102.

[0014] As used herein, the "leading edge" of a club head is the portion of the striking face that is closest to the sole. For example, as shown in FIG. 1, leading edge 103 is the transition from striking face 102 to sole 112 of club head 100.

[0015] As used herein, the "geometric center" of the striking face refers to the geometric center point of the striking face perimeter as shown in Figures 1-7. The geometric center 120 of the striking face 102 may be located according to the definition of a golf governing body, such as the United States Golf Association (USGA).

[0016] As used herein, "ground contact" refers to a reference plane relative to the surface on which a golf ball rests. The ground contact 1010 may be the horizontal plane that contacts the sole at the address position, which is defined in more detail below. The ground contact 1010 is shown in FIG. 3.

[0017] As used herein, the term "loft plane" may refer to a reference plane that is tangent to the geometric center of the striking face. A loft plane 1015 is shown in FIG.

[0018] As used herein, the term "loft angle" may refer to the angle measured between the loft plane and the XY plane (defined below).

[0019] As used herein, the term “lie angle” may refer to the angle between the hosel axis 1020 extending through the hosel 105 and the ground plane 1010 .

[0020] The club head 100 may define an "address position" (also referred to as "address"), where the club head 100 is oriented to define a desired loft and lie angle. For example, at the address position, the loft plane 1015 and the XY plane define the desired loft angle therebetween. Similarly, at the address position, the hosel axis 1020 and the ground plane 1010 define the desired lie angle therebetween.

[0021] As shown in FIGS. 3 and 4 , the club head 100 may define a primary coordinate system centered about the geometric center 120 of the striking face 102. The primary coordinate system may include an X-axis 1040, a Y-axis 1050, and a Z-axis 1060. The X-axis 1040 may extend in a heel-to-toe direction parallel to the contact surface 1010. The X-axis 1040 may be positive toward the heel 104 and negative toward the toe 106. The Y-axis 1050 may extend in a top rail-sole direction and may be perpendicular to both the contact surface 1010 and the X-axis 1040. The Y-axis 1050 may be positive toward the top rail 110 and negative toward the sole 112. The Z-axis 1060 may extend in a front-to-back direction parallel to the contact surface 1010 and may be perpendicular to both the X-axis 1040 and the Y-axis 1050. The Z-axis 1060 may be positive toward the striking face 102 and negative toward the rear end 111 .

[0022] The primary coordinate system described herein defines an XY plane as a vertical plane extending along the X-axis 1040 and the Y-axis 1050. The primary coordinate system defines an XZ plane as a horizontal plane extending along the X-axis 1040 and the Z-axis 1060. The primary coordinate system further defines a YZ plane as a vertical plane extending along the Y-axis 1050 and the Z-axis 1060. The XY, XZ, and YZ planes are all orthogonal to one another and intersect at the origin of the primary coordinate system, which is located at the geometric center 120 of the striking face 102. In these or other embodiments, the club head 100 is viewed from the front when the striking face 102 is viewed perpendicular to the XY plane. Furthermore, in these or other embodiments, the club head 100 is viewed from the side or in a side cross-sectional view when the heel 104 or toe 106 is viewed perpendicular to the YZ plane.

[0023] As used herein, the "center of gravity" or "CG" of a club head may refer to the point within the club head where mass is concentrated. CG 160 is shown in FIGS. 3 and 4.

[0024] The terms or phrases "center of gravity location" or "CG location" may refer to the location of the center of gravity (CG) of a club head relative to a primary coordinate system, where the CG location is identified by a location along the X-axis 1040, a location along the Y-axis 1050, and a location along the Z-axis 1060. The term "CGx" may refer to the CG location along the X-axis 1040, measured from the geometric center 120. The term "CG height" may refer to the CG location along the Y-axis 1050, measured from the geometric center 120. The term "CGy" is synonymous with CG height. The term "CG depth" may refer to the CG location along the Z-axis 1060, measured from the geometric center 120. The term "CGz" is synonymous with CG depth. The term "CG contact height" may refer to the vertical displacement (displacement parallel to the Y-axis 1050) of the CG 160 relative to the contact surface 1010. The term "CG leading edge depth" may refer to the horizontal displacement (displacement parallel to the Z-axis 1060) from the forward-most point of the leading edge 103. The CG leading edge depth may be expressed as the negative value of the distance aft from the leading edge 103.

[0025] The golf club head further includes a secondary coordinate system centered at the center of gravity 160. As shown in FIGS. 3 and 4 , the secondary coordinate system has an X′ axis 1070, a Y′ axis 1080, and a Z′ axis 1090. The X′ axis 1070 extends in the heel-to-toe direction. The X′ axis 1070 is positive toward the heel 104 and negative toward the toe 106. The Y′ axis 1080 extends in the sole-to-top rail direction and is perpendicular to both the Z′ axis 1090 and the X′ axis 1070. The Y′ axis 1080 is positive toward the top rail 110 and negative toward the sole 112. The Z′ axis 1090 extends in the front-to-back direction, is parallel to the contact surface 1010, and is perpendicular to both the X′ axis 1070 and the Y′ axis 1080. The Z′ axis 1090 is positive toward the striking face 102 and negative toward the rear end 111.

[0026] The term or phrase "moment of inertia" (hereinafter "MOI") may refer to a value derived using the center of gravity (CG) location. The terms "MOIxx" or "Ixx" may refer to the MOI measured about the X' axis 1070. The terms "MOIyy" or "Iyy" may refer to the MOI measured about the Y' axis 1080. The terms "MOIzz" or "Izz" may refer to the MOI measured about the Z' axis 1090. The MOI values ​​MOIxx, MOIyy, and MOIzz determine the club head 100's forgiveness on off-center hits with a golf ball.

[0027] The term "iron," as used herein, in some embodiments, may refer to an iron-type golf club head having a loft angle of less than about 50 degrees, less than about 49 degrees, less than about 48 degrees, less than about 47 degrees, less than about 46 degrees, less than about 45 degrees, less than about 44 degrees, less than about 43 degrees, less than about 42 degrees, less than about 41 degrees, or less than about 40 degrees. Furthermore, in many embodiments, the loft angle of the club head is greater than about 16 degrees, greater than about 17 degrees, greater than about 18 degrees, greater than about 19 degrees, greater than about 20 degrees, greater than about 21 degrees, greater than about 22 degrees, greater than about 23 degrees, greater than about 24 degrees, or greater than about 25 degrees.

[0028] In many embodiments, such as the "Game Improvement Iron" embodiments, the club head volume is approximately 65 cm 3 Less than 60cm 3 Less than 55cm 3 Less than or about 50cm 3 In some embodiments, the volume of the club head is less than about 50 cm 3 ~60cm 3 , approx. 51cm 3 ~53cm 3 , approx. 53cm 3 ~55cm 3 , approximately 55cm 3 ~57cm 3 , or approximately 57 cm 3 ~59cm 3 It may be.

[0029] In many embodiments, such as the "player's iron" embodiment, the club head volume is approximately 45 cm 3 Less than 40cm 3 Less than 35cm 3 Less than or about 30cm 3 In some embodiments, the club head volume is less than about 31 cm 3 ~38cm 3 (1.9 cubic inches to 2.3 cubic inches), approximately 31 cm 3 ~33cm 3 , about 33cm 3 ~35cm 3 , about 35cm 3 ~37cm 3 , or approximately 37 cm 3 ~39cm 3 It may be.

[0030] In some embodiments, the total mass of the iron may be between 180 grams and 260 grams, between 190 grams and 240 grams, between 200 grams and 230 grams, between 210 grams and 220 grams, or between 215 grams and 220 grams. In some embodiments, the total mass of the club head is 215 grams, 216 grams, 217 grams, 218 grams, 219 grams, or 220 grams.

[0031] As used herein, the term "hollow body iron" refers to an iron-type golf club head having an enclosed internal cavity. Hollow body irons are often used to enhance distance potential by supporting the face with a continuous back wall design, acting as a springboard or drum.

[0032] As used herein, the term "cavity back iron" refers to an iron-type golf club head having an open rear cavity. Cavity back irons typically have the majority of their mass on the periphery of the body, making them more forgiving and desirable for high-handicap golfers.

[0033] In some embodiments, the iron-type club head may include a rear opening that is covered by a badge such that the internal cavity is closed. In such embodiments, closing the rear opening converts the open rear cavity into a closed internal cavity. Thus, embodiments with a badge covering the rear opening may be considered both cavity back irons and hollow body irons.

[0034] As used herein, the words and phrases "blade-style iron" or "muscle-back iron" refer to iron-type golf club heads that have a solid body without any cavities, recesses, openings, or voids. Blade-style irons and muscle-back irons generally favor low-handicap golfers because they offer less forgiveness and more workability.

[0035] Ixx of iron type club head is 500g*cm 2 ~2000g*cm 2 In some embodiments, Ixx may be 500 g*cm 2 ~800g*cm 2 , 800g*cm 2 ~1100g*cm 2 , 1100g*cm 2 ~1400g*cm 2 , 1400g*cm 2 ~1700g*cm 2 , or 1700g*cm 2 ~2000g*cm 2 In some embodiments, Ixx may be 500 g*cm 2 Over 600g*cm 2 Over 700g*cm 2 Over 800g*cm 2 Over 900g*cm 2 Over 1000g*cm 2 Over 1100g*cm 2 Over 1200g*cm 2 Over 1300g*cm 2 Over 1400g*cm 2Over 1500g*cm 2 Over 1600g*cm 2 Over 1700g*cm 2 Over 1800g*cm 2 Over 1900g*cm 2 It may be beyond that.

[0036] The Iyy of an iron club head is 2000g*cm 2 ~4000g*cm 2 In some embodiments, Iyy may be 2000 g*cm 2 ~2250g*cm 2 , 2250g*cm 2 ~2500g*cm 2 , 2500g*cm 2 ~2750g*cm 2 , 2750g*cm 2 ~3000g*cm 2 , 3000g*cm 2 ~3250g*cm 2 , 3250g*cm 2 ~3500g*cm 2 , 3500g*cm 2 ~3750g*cm 2 , or 3750g*cm 2 ~4000g*cm 2 In some embodiments, Iyy may be 2000 g*cm 2 Over 2100g*cm 2 Over 2200g*cm 2 Over 2300g*cm 2 Over 2400g*cm 2 Over 2500g*cm 2 Over 2600g*cm 2 Over 2700g*cm 2 Over 2800g*cm 2 Over 2900g*cm 2 Over 3000g*cm 2 Over 3100g*cm 2 Over 3200g*cm 2 Over 3300g*cm 2 Over 3400g*cm 2 Over 3500g*cm2 Over 3600g*cm 2 Over 3700g*cm 2 Over 3800g*cm 2 Over 3900g*cm 2 It may be beyond that.

[0037] The Izz of an iron club head is 2000g*cm 2 ~4000g*cm 2 In some embodiments, Izz may be 2000 g*cm 2 ~2250g*cm 2 , 2250g*cm 2 ~2500g*cm 2 , 2500g*cm 2 ~2750g*cm 2 , 2750g*cm 2 ~3000g*cm 2 , 3000g*cm 2 ~3250g*cm 2 , 3250g*cm 2 ~3500g*cm 2 , 3500g*cm 2 ~3750g*cm 2 , or 3750g*cm 2 ~4000g*cm 2 In some embodiments, Iyy may be 2000 g*cm 2 Over 2100g*cm 2 Over 2200g*cm 2 Over 2300g*cm 2 Over 2400g*cm 2 Over 2500g*cm 2 Over 2600g*cm 2 Over 2700g*cm 2 Over 2800g*cm 2 Over 2900g*cm 2 Over 3000g*cm 2 Over 3100g*cm 2 Over 3200g*cm 2 Over 3300g*cm 2 Over 3400g*cm 2 Over 3500g*cm 2Over 3600g*cm 2 Over 3700g*cm 2 Over 3800g*cm 2 Over 3900g*cm 2 It may be beyond that.

[0038] The CGy position of an iron-type club head may be between -0.10 and -0.25 inches. In some embodiments, the CGy position may be between -0.10 and -0.15 inches, between -0.15 and -0.20 inches, or between -0.20 and -0.25 inches. In some embodiments, the CGy position may be less than -0.10 inches, less than -0.12 inches, less than -0.14 inches, less than -0.16 inches, less than -0.18 inches, less than -0.20 inches, less than -0.22 inches, less than -0.24 inches, or less than -0.25 inches.

[0039] The CGz position of an iron-type club head may be between -0.15 and -0.05 inches. In some embodiments, the CGz position may be between -0.15 and -0.13 inches, between -0.13 and -0.11 inches, between -0.11 and -0.09 inches, between -0.09 and -0.07 inches, or between -0.07 and -0.05 inches. In some embodiments, the CGz position may be greater than -0.15 inches, less than -0.13 inches, less than -0.11 inches, less than -0.09 inches, less than -0.07 inches, or less than -0.05 inches.

[0040] The CG ground height of the iron-type club head may be between 0.25 inches and 0.75 inches. In some embodiments, the CG ground height may be between 0.25 inches and 0.35 inches, between 0.35 inches and 0.45 inches, between 0.45 inches and 0.55 inches, between 0.55 inches and 0.65 inches, or between 0.65 inches and 0.75 inches. In some embodiments, the CG ground height may be less than 0.75 inches, less than 0.65 inches, less than 0.55 inches, less than 0.45 inches, less than 0.35 inches, or less than 0.25 inches.

[0041] The CG leading edge depth of an iron-type club head may be between -0.25 inches and -0.75 inches. In some embodiments, the CG ground height may be between -0.25 inches and -0.35 inches, between -0.35 inches and -0.45 inches, between -0.45 inches and -0.55 inches, between -0.55 inches and -0.65 inches, or between -0.65 inches and -0.75 inches. In some embodiments, the CG ground height may be greater than -0.75 inches, greater than -0.65 inches, greater than -0.55 inches, greater than -0.45 inches, greater than -0.35 inches, or greater than -0.25 inches.

[0042] Before embodiments of the present disclosure are described 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 elements set forth below or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or carried out in various ways. explanation

[0043] Described herein are various embodiments of iron-type golf club heads with inserts that optimize vibration damping and performance characteristics. The inserts described herein dampen vibrations while maintaining a large amount of discretionary mass. The inserts are received in the club head's internal cavity through one or more rear openings and partially or completely fill the internal cavity.

[0044] The insert provides a club head with an improved balance of performance and vibration damping. The insert contacts a large portion of the club head body and can dampen vibrations generated therein. The insert may be formed of a lightweight material having a density lower than that of the body. Thus, the insert provides significant vibration damping without adding significant mass to the club head. The insert effectively replaces a portion of the high-density body with a low-density material, thereby increasing discretionary mass compared to blade-style irons. In many embodiments, the insert can provide the club head with a multi-material solid structure that achieves vibration characteristics similar to those of a solid structure of a blade-style iron. In many embodiments, a club head with one or more rear openings and a lightweight insert can produce 25 grams or more of discretionary mass compared to a similar blade-style iron with a single-material solid body. Compared to hollow-body or cavity-back irons, the club heads described herein can dampen vibrations and provide a favorable sound and feel while maintaining or improving performance.

[0045] In some specific embodiments, at least one surface of the insert may be exposed to the rear exterior of the club head through one or more rear openings. In some embodiments, the insert has an exposed outer surface that forms 30% or more of the surface area of ​​the rear wall. Leaving the outer surface of the insert exposed through the rear openings preserves discretionary mass. The rear openings remove mass from the rear wall, and leaving the outer surface of the insert exposed prevents reintroduction of mass to cover the openings. In other embodiments, one or more rear openings may be covered and / or sealed with one or more badges. In such embodiments, one or more badges may cover the outer surface of the insert, and the insert may be hidden within an internal cavity. In some specific embodiments, no surface of the insert is exposed to the exterior of the club head. Covering and / or sealing one or more rear openings with badges can protect the insert from the exterior of the club head. In this manner, the insert may have a low density and / or low hardness, thereby increasing discretionary mass, without compromising the durability of the insert.

[0046] In some embodiments, the insert may include a lattice structure having a plurality of internal and / or external voids. Thus, the lattice structure insert has an effective density that is lower than the density of the material used to form the insert. Furthermore, the effective density of the lattice insert may be strategically varied to improve the mass properties of the club head. In some embodiments, the lattice insert may have a uniform effective density, or the uniform effective density may vary between different embodiments. In some embodiments, the lattice insert may have different effective densities, such as a higher effective density in some portions of the insert and a lower effective density in other portions of the insert. In such embodiments, the varying effective density of the lattice insert can be adjusted to achieve a desired mass distribution. I. Overview of each element A. Rear opening

[0047] 1-7 illustrate iron-type club heads having an insert and one or more rear openings in the body. Referring to FIGS. 5 and 6, the club heads may have one or more openings to an internal cavity. The club head has a rear wall, and the rear openings are formed through the rear wall. The rear openings fluidly connect the exterior of the club head to the internal cavity. The rear openings serve multiple purposes. The rear openings create discretionary mass by reducing the mass of the rear wall compared to hollow-body irons that have a continuous rear wall to close the internal cavity or blade-style irons that have a solid body structure. Additionally, the rear openings provide access to the internal cavity, allowing for the placement of an insert (described in further detail below) within the internal cavity.

[0048] As shown in Figures 5 and 6, the rear wall may be divided into an upper rear wall and a lower rear wall. The rear wall may have a flex joint extending generally horizontally on the rear wall from near the heel to near the toe. In many embodiments, the flex joint forms a boundary between the upper rear wall and the lower rear wall. The upper rear wall may be located between the top rail and the flex joint (or may be defined by the top rail and the flex joint). The lower rear wall may be located between the flex joint and the sole (or may be defined by the flex joint and the sole).

[0049] With continued reference to FIGS. 5 and 6 , the club head includes a single opening disposed in the upper rear wall. In some embodiments, many of which are described in further detail below, the club head may include one or more openings disposed in the upper rear wall, one or more openings disposed in the lower rear wall, or a combination thereof. In some embodiments, the club head may include one opening, two openings, three openings, four openings, five openings, or any suitable number of openings in the upper rear wall. In some embodiments, the club head may include one opening, two openings, three openings, four openings, five openings, or any suitable number of openings in the lower rear wall. In some embodiments, the club head may include any combination of any number of openings in the upper rear wall and any number of openings in the lower rear wall.

[0050] In some embodiments, the rear opening may occupy a majority of the rear wall. The size of the rear opening may be characterized by an opening exposed area. The opening exposed area may be calculated as the two-dimensional surface area of ​​the rear opening projected onto the loft plane. In some embodiments, the rear opening is between 0.50 and 3.50 in. 2 In embodiments with multiple rear openings, each rear opening may individually have an exposed opening area within the above ranges. Furthermore, in those embodiments with multiple rear openings, the rear openings may have an exposed opening area within the above ranges. 2 may have a total open exposed area of

[0051] The size of the rear opening can also be characterized by comparing the exposed opening area to the surface area of ​​the rear wall. For comparison, the surface area of ​​the rear wall is measured as if the rear wall were continuous and had no openings. The surface area of ​​the rear wall can be calculated by replacing the rear opening with an imaginary plane that defines the portion of the rear wall removed by the rear opening. In some embodiments, the rear opening has an exposed opening area that is between 15% and 85% of the rear wall surface area. In some embodiments, the rear opening has an exposed opening area that is between 15% and 25%, 25% and 35%, 35% and 45%, 45% and 55%, 55% and 65%, 65% and 75%, or 75% and 85% of the rear wall surface area. In some embodiments, the rear opening has an open exposed area of ​​greater than 15%, greater than 20%, greater than 25%, greater than 30%, greater than 35%, greater than 40%, greater than 45%, greater than 50%, greater than 55%, greater than 60%, greater than 65%, greater than 70%, greater than 75%, greater than 80%, or greater than 85% of the rear wall surface area. In embodiments with multiple rear openings, each rear opening individually may have an open exposed area within the above percentages. Further, in such embodiments with multiple rear openings, the rear openings may have a total open exposed area of ​​between 25% and 95% of the rear wall surface. In some embodiments, the total open exposed area may be between 25% and 35%, 35% and 45%, 45% and 55%, 55% and 65%, 65% and 75%, 75% and 85%, or 85% and 95% of the rear wall surface. In some embodiments, the total open exposed area may be greater than 25%, greater than 30%, greater than 35%, greater than 40%, greater than 45%, greater than 50%, greater than 55%, greater than 60%, greater than 65%, greater than 70%, greater than 75%, greater than 80%, greater than 85%, greater than 90%, or greater than 95% of the rear wall surface.

[0052] As discussed above, rear openings create discretionary mass by removing mass from the rear wall compared to both hollow-body irons and blade-style irons. In particular, the provision of one or more rear openings helps improve the CG location of the club head. Because the rear openings remove mass from the rear wall, the CG moves forward. Similarly, in embodiments in which rear openings are provided in the upper rear wall (discussed in more detail below), the rear openings remove mass high in the club head, thereby moving the CG lower. A lower, forward CG location in an iron-type club head increases ball speed and launch angle at impact, resulting in better launch characteristics. Thus, the provision of one or more rear openings and / or one or more rear openings in the upper rear wall results in a CG ground height of less than 0.75 inches, less than 0.65 inches, less than 0.55 inches, less than 0.45 inches, less than 0.35 inches, or less than 0.25 inches, and / or a CG leading edge depth of greater than -0.75 inches, greater than -0.65 inches, greater than -0.55 inches, greater than -0.45 inches, greater than -0.35 inches, or greater than -0.25 inches. B. Insert

[0053] 2 and 7, the golf club head further includes a low-density insert configured to be received within the internal cavity. The insert improves the sound and feedback (or "feel") characteristics of the club head by damping vibrations generated at the inner surface of the club head body that defines the internal cavity. The insert may provide a large contact area with the inner surface of the club head body. In particular, the insert may provide a large contact area with the rear surface of the striking face to dampen vibrations generated at the striking face during impact. Furthermore, because the insert is made of a low-density material that replaces the high-density core body material compared to blade-style irons, discretionary mass is created.

[0054] The insert material may include an elastomer, a thermoplastic, a thermoplastic polyurethane (TPU), a thermoplastic elastomer (TPE), a polyurethane (PU), a thermoplastic composite (TPC), or any other suitable polymer. For example, in some embodiments, the insert material may be ethylene-vinyl acetate polyurethane (EVA PU). In other embodiments, the insert material may be low-density polyethylene (LDPE), polyethylene (PE), nitrile rubber (NBR), neoprene, polyimide, polypropylene (PP), polystyrene (PS), polyethylene, polyvinyl chloride (PVC), ethylene, vinyl acetate, polyolefin copolymer, styrene, styrene-butadiene, a polyurethane elastomer, a silicone elastomer, rubber, or vulcanized natural rubber latex, an epoxy, a resin, an adhesive, a polyurethane adhesive, a glue, a silicone, or any combination thereof. In some embodiments, the insert material may include a composite material, such as an elastomer containing a metal powder. In some embodiments, the insert material may be a material suitable for molding by additive manufacturing, such as 3D printing. In many embodiments, the insert may be a solid molded polymer, a polymer foam, a lightweight viscoelastic foam, a metal foam, a lattice, or a combination thereof.

[0055] The insert may be formed of a very light material that provides a high level of damping while retaining discretionary mass. The insert has a density that is less than the body density of the club head. In some embodiments, the insert density is less than 0.75 g / cm. 3 ~2g / cm 3 In some embodiments, the insert density may be 0.75 g / cm 3 ~0.85g / cm 3 , 0.85g / cm 3 ~1.0g / cm 3 , 1.0g / cm 3 ~1.1g / cm 3 , 1.1g / cm 3 ~1.2g / cm 3 , 1.2g / cm 3 ~1.3g / cm 3 , 1.3g / cm3 ~1.4g / cm 3 , 1.4g / cm 3 ~1.5g / cm 3 , 1.5g / cm 3 ~1.6g / cm 3 , 1.6g / cm 3 ~1.7g / cm 3 , 1.7g / cm 3 ~1.8g / cm 3 , 1.8g / cm 3 ~1.9g / cm 3 , or 1.9 g / cm 3 ~2.0g / cm 3 In some embodiments, the insert density may be 2.0 g / cm 3 Less than 1.8g / cm 3 Less than 1.6g / cm 3 Less than 1.4g / cm 3 Less than 1.2g / cm 3 Less than 1.0 g / cm 3 Less than 0.8g / cm 3 Less than or equal to 0.75 g / cm 3 The insert's lightweight density allows for the replacement of high-density body material with low-density insert material to create discretionary mass compared to blade-style irons. In some embodiments, the insert density is uniform. In other embodiments, the insert density may vary within the insert.

[0056] The density of the insert may be significantly less than the density of the body. The club head may have an insert density ratio, defined as the density of the insert divided by the density of the body. In many embodiments, the insert density ratio may be between 0.10 and 0.40. In many embodiments, the insert density ratio may be between 0.10 and 0.20, 0.15 and 0.25, 0.20 and 0.30, 0.25 and 0.35, or 0.30 and 0.40. In many embodiments, the insert density ratio may be less than 0.40, less than 0.35, less than 0.30, less than 0.25, less than 0.20, less than 0.15, or less than 0.10.

[0057] The insert density may be different for embodiments in which the insert is exposed to the exterior of the club head than for embodiments in which the insert is covered by a badge (discussed in more detail below). In some embodiments in which the insert is exposed, the insert density is 1.0 g / cm 3 ~2.0g / cm 3 In some embodiments where the insert is exposed, the insert density may be 1.0 g / cm 3 Exceeds 1.1g / cm 3 Over 1.2g / cm 3 Over 1.3g / cm 3 Over 1.4g / cm 3 Over 1.5g / cm 3 Over 1.6g / cm 3 Over 1.7g / cm 3 Over 1.8g / cm 3 Exceeding or 1.9 g / cm 3 If the insert is exposed, the insert material may have a higher density (i.e., 1.0 g / cm3) to protect the insert from environmental damage. 3 It may be required to have a density exceeding 1000 kJ / cm2.

[0058] In embodiments where the insert is covered with a badge, the insert density is 0.75 g / cm 3 ~1.5g / cm 3 In some embodiments where the insert is covered with a badge, the insert density may be 1.5 g / cm 3 Less than 1.4g / cm 3 Less than 1.3g / cm 3 Less than 1.2g / cm 3 Less than 1.1g / cm 3 Less than 1.0 g / cm 3 Less than 0.9g / cm 3 Less than 0.8g / cm 3 Less than or equal to 0.75 g / cm 3If the insert is covered with a badge, the badge provides protection against environmental damage. Therefore, the insert material should be as light as possible (i.e., density less than 1.5 g / cm) without concern for durability. 3 (less than 1000 kJ / min)

[0059] The insert provides a high level of damping without adding significant mass to the club head. In many embodiments, the insert mass may be between 0.5 grams and 30 grams. In some embodiments, the insert mass may be between 0.5 grams and 5 grams, between 5 grams and 10 grams, between 10 grams and 15 grams, between 15 grams and 20 grams, between 20 grams and 25 grams, or between 25 grams and 30 grams. In some embodiments, the insert mass may be less than 25 grams, less than 20 grams, or less than 15 grams. In some embodiments, the insert mass may be less than 10 grams, less than 9 grams, less than 8 grams, less than 7 grams, less than 6 grams, less than 5 grams, less than 4 grams, less than 3 grams, less than 2 grams, less than 1 gram, or less than 0.5 grams. As noted above, the insert is formed from a lightweight material. In various embodiments, the insert mass may vary depending on the size of the club head, the volume of the internal cavity, the insert density, and the volume of the insert.

[0060] In some embodiments, the insert is exposed to the exterior of the club head, as shown in FIGS. 2 and 7. In such embodiments, the insert has an insert outer surface that is exposed through the rear opening. A portion of the insert may extend through the rear opening and at least partially fill the rear opening. In such embodiments, the insert outer surface forms at least a portion of the rear face of the club head. In some embodiments, the insert outer surface may be flush with the surface of the surrounding rear wall. In other embodiments, the insert outer surface is recessed from the surface of the surrounding rear wall, such that the insert does not extend completely through the rear opening. The degree of exposure of the insert is characterized by the insert exposed area. The insert exposed area is the surface area of ​​the insert outer surface that is exposed and / or visible through the rear opening. In some embodiments, the club head has a depth of 0.50 to 4.00 in. 2 In some embodiments, the exposed insert area is between 0.50 and 1.00 in 2 , 1.00~1.50in 2 , 1.50~2.00in 2 , 2.00~2.50in 2 , 2.50~3.00in 2 , 3.00~3.50in 2 , or 3.50-4.00in 2 In some embodiments, the exposed area of ​​the insert may be 0.50 in 2 Over 0.70in 2 Over 0.90in 2 Over 1.10in 2 Over 1.30in 2 Over 1.50in 2 Over 1.70in 2 Over 1.90in 2 Over 2.10 inches 2 Over 2.30in 2 Over 2.50 inches 2 Over 2.70 inches 2 Over 2.90 inches 2 Over 3.10 inches 2 Over 3.30in 2 Over 3.50 inches2 Over 3.70 inches 2 Over 3.90 inches 2 It may be beyond that.

[0061] In some embodiments, the insert has a hardness of Shore A10 to Shore D80. In some embodiments, the insert hardness may be Shore A10 to Shore A30, Shore A30 to Shore A50, Shore A50 to Shore A70, Shore A70A to Shore A90, Shore D40 to Shore D50, Shore D50 to Shore D60, Shore D60 to Shore D70, or Shore D70 to Shore D80. In some embodiments, the insert has a uniform hardness. In other embodiments, the insert may have a varying hardness within the insert.

[0062] The insert hardness in embodiments where the insert is exposed to the exterior of the club head may be higher than the insert hardness in embodiments where the insert is covered with a badge. In embodiments where the insert is exposed to the exterior of the club head, the insert hardness may be between Shore A60 and Shore D80. In some embodiments where the insert is exposed, the insert hardness may be greater than Shore A60, greater than Shore A70, greater than Shore A80, greater than Shore A90, greater than Shore D40, greater than Shore D50, greater than Shore D60, greater than Shore D70, or greater than Shore D80. When the insert is exposed, the insert material may be required to have a higher hardness (i.e., greater than Shore A60) to protect the insert from environmental damage.

[0063] In embodiments where the insert is covered with a badging, the insert hardness may be between Shore A10 and Shore A60. In some embodiments where the insert is covered, the insert hardness may be less than Shore A60, less than Shore A50, less than Shore A40, less than Shore A30, less than Shore A20, or less than Shore A10. When the insert 140 is covered with a badging, the badging provides protection against environmental damage. Therefore, the insert material may be as soft as necessary (i.e., less than Shore A60) without concern for durability.

[0064] In some embodiments, the insert completely fills the internal cavity. In such embodiments, the insert is shaped to complement the shape of the internal cavity. The insert may completely fill the internal cavity such that the insert contacts the entire inner surface of the club head body that defines the internal cavity. In some embodiments in which the insert completely fills the internal cavity, the insert is substantially solid, with no voids formed within the insert. In embodiments in which the insert completely fills the internal cavity, the insert and the club head body together form a multi-material solid structure with no voids or spaces formed therebetween. The multi-material solid structure of this embodiment resembles the single-material solid structure of a blade-style iron, improving the balance between vibration damping and performance, but with more discretionary mass.

[0065] Compared to hollow-body irons, the presence of an insert can provide greater forgiveness when the insert completely fills the internal cavity. Typical hollow-body irons exhibit erratic curvature on off-center hits, resulting in a "flyer" golf shot where the ball lacks spin and travels much farther than intended. The insert completely fills the entire internal cavity, stabilizing the curvature of the club head. Stabilizing the curvature of the club head results in more predictable shot distances, especially on off-center hits.

[0066] In other embodiments, the insert may only partially fill the internal cavity. Providing an insert that partially fills the internal cavity may provide greater discretionary mass and a higher level of vibration damping compared to embodiments in which the insert completely fills the internal cavity. In embodiments in which the insert partially fills the internal cavity, voids and / or spaces remain within the internal cavity. In some embodiments, the club head may include a solid insert that resides only in a specific portion of the internal cavity. In such embodiments, one or more voids and / or spaces may exist between the insert and the body. In other embodiments, the club head may include an insert that resides throughout the internal cavity but includes a lattice structure that defines one or more voids and / or spaces within the insert itself. While the profile of the lattice insert may reside throughout the internal cavity, the lattice insert is considered to partially fill the cavity because the insert itself has voids. Insert embodiments with lattice structures are described in more detail below.

[0067] In some embodiments, the volume of the insert is 2 cm 3 ~25cm 3 In some embodiments, the volume of the insert may be 2 cm 3 ~5cm 3 , 5cm 3 ~10cm 3 , 10cm 3 ~15cm 3 , 15cm 3 ~20cm 3 , or 20cm 3 ~25cm 3 In some embodiments, the volume of the insert may be 2 cm 3 Over 3cm 3 Over 4cm 3 Over 5cm 3 Over 6cm 3 Over 7cm 3 Over 8cm3 Over 9cm 3 Over 10cm 3 Over 11cm 3 Over 12cm 3 Over 13cm 3 Over 14cm 3 Over 15cm 3 Over 16cm 3 Over 17cm 3 Over 18cm 3 Over 19cm 3 Over 20cm 3 Over 21cm 3 Over 22cm 3 Over 23cm 3 Over 24cm 3 Over 25cm 3 In embodiments in which the insert completely fills the internal cavity, the volume of the insert may be approximately the same as the volume of the internal cavity. In embodiments in which the insert partially fills the internal cavity, the volume of the insert may be less than the volume of the internal cavity.

[0068] In some embodiments where the insert only partially fills the internal cavity, the insert may fill 5% to 85% of the volume of the internal cavity. In some embodiments, the insert may fill 5% to 15%, 15% to 25%, 25% to 35%, 35% to 45%, 45% to 55%, 55% to 65%, 65% to 75%, or 75% to 85% of the volume of the internal cavity. In some embodiments, the insert may fill more than 5%, more than 10%, more than 15%, more than 20%, more than 25%, more than 30%, more than 35%, more than 40%, more than 45%, more than 50%, more than 55%, more than 60%, more than 65%, more than 69%, more than 70%, more than 75%, more than 80%, or more than 85% of the volume of the internal cavity. Although the club head has one or more rear openings, the volume of the internal cavity may be considered as enclosing the volume defined therein by covering the one or more rear openings with an imaginary surface.

[0069] As described above, providing an insert that completely or partially fills the internal cavity creates discretionary mass compared to a blade-style iron having a solid construction formed entirely from a high-density body material. In embodiments where the insert completely fills the internal cavity, the insert can create 5 to 25 grams of discretionary mass compared to a similarly shaped blade-style iron. In some embodiments where the insert completely fills the internal cavity, the insert can create more than 5 grams, more than 10 grams, more than 15 grams, more than 20 grams, or more than 25 grams of discretionary mass compared to a similarly shaped blade-style iron. Furthermore, in embodiments where the insert partially fills the internal cavity, the insert can create 15 to 40 grams of discretionary mass compared to a similarly shaped blade-style iron. In some embodiments where the insert partially fills the internal cavity, the insert can create more than 15 grams, more than 20 grams, more than 25 grams, more than 30 grams, more than 35 grams, or more than 40 grams of discretionary mass compared to a similarly shaped blade-style iron.

[0070] The discretionary mass created by replacing the solid structure of a blade-style iron with an internal cavity at least partially filled by an insert may be redistributed to the periphery of the club head to increase the MOI. In particular, by redistributing the discretionary mass created by providing an insert to fill the internal cavity to the periphery of the club head, Iyy can be increased by 5% to 15% compared to a similarly shaped blade-style club head. In some embodiments, the insert can increase Iyy by more than 5%, more than 6%, more than 7%, more than 8%, more than 9%, more than 10%, more than 11%, more than 12%, more than 13%, more than 14%, or more than 15% compared to a similarly shaped blade-style club head. As discussed above, the rear opening allows for a more forward and lower CG position. In this way, a club head with a rear opening and an insert can improve both CG position and MOI, resulting in better launch characteristics, forgiveness, and dispersion area.

[0071] In some embodiments, the insert may be injected into the internal cavity in a liquid state through at least one rear opening or another port. After being injected into the internal cavity, the liquid insert material solidifies to form the insert. In some embodiments, after the desired amount of insert material has been injected, the outer surface of the insert may be machined or otherwise finished to the desired shape and left exposed. In other embodiments, a badge (described in further detail below) may be placed in the rear opening and secured to the club head to cover the solidified insert.

[0072] In other embodiments where the insert is exposed through the rear opening, the insert may be co-molded with the body. A negative mold may be placed on the rear wall. After the negative mold is placed, the insert material may be injected into the internal cavity to fill the entire internal cavity. The negative mold prevents the insert material from flowing out of the rear opening. Additionally, the negative mold allows the insert material to form a surface flush with the surface of the rear wall. C. Badges

[0073] In some embodiments, the insert may not be exposed to the exterior of the club head and may be covered with a badge. The badge may be connected to the body of the club head to cover one or more rear openings. The badge may be connected to the body by epoxy adhesive, tape, mechanical means, or other suitable joining method. The badge may partially or completely close the internal cavity so that the insert is hidden within the internal cavity. In some embodiments, the badge completely conceals the insert within the internal cavity and makes the insert invisible from the exterior of the club head. The badge may protect the insert from environmental damage. In this regard, covering the insert with a badge allows the insert to be formed from a material with a low density and / or low hardness, thereby allowing for discretionary mass without compromising the insert's durability. In some embodiments, the club head may include multiple badges. In some embodiments with multiple rear openings, a separate badge may cover each of the rear openings. In other embodiments, a single badge may cover multiple rear openings.

[0074] In some embodiments, the badge may be formed of a lightweight metal material, including, but not limited to, aluminum or an aluminum alloy. In other embodiments, the badge may be constructed from a lightweight polymer, plastic material, or composite material. In some embodiments, the badge is constructed from multiple materials. In some embodiments, the badge has a density less than the density of the body of the club head. Although mass is reintroduced by the badge to cover one or more rear openings, discretionary mass is preserved by covering the rear openings with the lightweight badge because the mass of the badge is less than the mass of the reduced rear wall. II. Embodiments A. Rear opening in the upper rear wall

[0075] 1-16 illustrate various embodiments of club heads 100, 200, 300, 400, 500, 600, 700, and 800 that include one or more rear openings and an insert that completely fills the internal cavity. The provision of an insert that completely fills the internal cavity results in a club head with a multi-material solid construction. In a multi-material solid construction, the club head has no voids or open spaces within it. As discussed above, a solid body construction (such as that of a blade-style iron) reduces vibrations at impact compared to those experienced in hollow-body irons or cavity-back irons with thin bodies. Club heads with a fully filled internal cavity insert resemble the solid body construction of a blade-style iron, but provide greater discretionary mass by essentially replacing the core body material of the blade-style iron with a lightweight insert. The provision of an insert that completely fills the internal cavity maximizes vibration damping while still providing discretionary mass compared to irons with a solid construction.

[0076] 1-7 illustrate a club head 100 with a rear opening 130 and an insert 140 that completely fills the internal cavity 107. The club head 100 includes one rear opening 130 located in the upper rear wall 122. As shown in FIG. 5, the rear opening 130 extends across a majority of the upper rear wall 122. The rear opening 130 may extend from near the heel 104 to near the toe 106, and may extend from near the flex joint 125 to near the top rail 110.

[0077] As shown in Figure 5, the rear opening 130 may have a very large exposed area. In some embodiments, the rear opening 130 may be 1.300 to 1.900 inches. 2 For example, the rear opening 130 may have an exposed opening area of ​​1,300 to 1,400 inches. 2 , 1.400~1.500in 2 , 1.500~1.600in 2 , 1.600~1.700in 2 , 1.700~1.800in 2 , or 1,800 to 1,900 inches 2 In some embodiments, the rear opening 130 may have an exposed opening area of ​​1.30 in. 2 Over 1.35in 2 Over 1.40in 2 Over 1.45in 2 Over 1.50in 2 Over 1.55in 2 Over 1.60in 2 Over 1.65in 2 Over 1.70in 2 Over 1.75in 2 Over 1.80in 2 Over 1.85 inches 2 In some embodiments, the rear opening may have an exposed opening area of ​​about 1.593 in. 2 The exposed area is .

[0078] The rear opening 130 may occupy a majority of the upper rear wall 122. In many embodiments, the rear opening 130 may have an open exposed area that is 60% to 95% of the upper rear wall surface area. In some embodiments, the rear opening 130 may form 60% to 70%, 70% to 80%, or 80% to 95% of the upper rear wall. In some embodiments, the rear opening 130 forms approximately 81.2% of the upper rear wall area.

[0079] The rear opening 130 may have a large exposed area relative to the overall surface area of ​​the rear wall 116. In many embodiments, the rear opening 130 may have an open exposed area that is 20% to 50% of the overall surface area of ​​the rear wall 116. In some embodiments, the rear opening 130 may form an open exposed area that is 20% to 25%, 25% to 30%, 30% to 35%, 35% to 40%, 40% to 45%, or 45% to 50% of the overall surface area of ​​the rear wall 116. For example, in some embodiments, the rear opening 130 forms approximately 35% of the overall surface area of ​​the rear wall 116.

[0080] As shown in FIGS. 5-7 , the club head 100 does not include an opening in the lower rear wall 124. Because the rear opening 130 removes mass from the upper rear wall 122 but does not remove mass from the lower rear wall 124, the club head 100 has a low CG height. In some embodiments, the club head 100 may have a CG ground height of 0.25 inches to 0.35 inches, 0.35 inches to 0.45 inches, 0.45 inches to 0.55 inches, 0.55 inches to 0.65 inches, or 0.65 inches to 0.75 inches. In some embodiments, the club head may have a CG ground height of less than 0.75 inches, less than 0.65 inches, less than 0.55 inches, less than 0.45 inches, less than 0.35 inches, or less than 0.25 inches.

[0081] As described above, the club head 100 includes an insert 140 that completely fills the internal cavity 107. As shown in FIG. 7 , the insert 140 extends from the striking face 102 to the rear wall 116 and from the sole 112 to the top rail 110. The insert 140 has a shape that is complementary to the internal cavity 107, such that no gap is formed between the insert 140 and the club head body 101. Additionally, the upper portion of the insert 140 extends through and fills the rear opening 130. The insert 140 includes an insert outer surface 145 that is exposed through the rear opening 130 and forms a portion of the rear face of the club head. In some embodiments, the insert outer surface 145 is substantially flush with the upper rear wall 122, thereby providing a continuous appearance to the rear wall 116. In this manner, the insert 140 provides a multi-material solid club head structure that resembles the solid structure of a blade-style iron, but creates more discretionary mass.

[0082] In some embodiments, the insert 140 forms a substantial portion of the rear face 116 of the club head within the upper rear wall 122. In many embodiments, the insert 140 forms a substantial portion of the rear face 116 of the club head within the upper rear wall 122. 2 For example, the exposed area of ​​the insert is 1.300 to 1.400 in 2 , 1.400~1.500in 2 , 1.500~1.600in 2 , 1.600~1.700in 2 , 1.700~1.800in 2 , or 1,800 to 1,900 inches 2 In some embodiments, the insert 140 may have an area of ​​about 1.593 in 2 The exposed area is .

[0083] Additionally, the insert 140 may form a substantial portion of the entire rear surface of the club head. Thus, the insert 140 may have a large exposed insert area relative to the entire rear wall 116. In many embodiments, the insert 140 may have an exposed insert area that is 20% to 50% of the entire surface area of ​​the rear wall 116. In some embodiments, the rear opening 130 may form 20% to 25%, 25% to 30%, 30% to 35%, 35% to 40%, 40% to 45%, or 45% to 50% of the entire surface area of ​​the rear wall 116. For example, in some embodiments, the rear opening 130 forms approximately 35% of the entire surface area of ​​the rear wall 116.

[0084] The insert 140 may be formed of a relatively hard insert material to allow for a large insert exposed area without compromising the durability of the insert 140. In some embodiments, the insert 140 may have a hardness greater than Shore A 60, greater than Shore A 70, greater than Shore A 80, greater than Shore A 90, greater than Shore D 40, greater than Shore D 50, greater than Shore D 60, greater than Shore D 70, or greater than Shore D 80. Having a high hardness (greater than Shore A 60) protects the exposed insert outer surface 145 from damage during use. B. Rear opening and badge on the upper rear wall

[0085] 8 and 9 show a club head 200 with a rear opening 240 in the upper rear wall 222. The club head 200 may be very similar to the club head 100, except that the club head 200 includes a badge 250 that covers the rear opening 230 and hides the insert 240 within the interior cavity 207. Because the badge 250 protects the insert 240, it is possible to use a lower hardness (i.e., less than Shore A 60) and density (i.e., less than 1.5 g / cm 3 This allows the insert 240 to be formed from less (less than 100%) of material, thereby increasing discretionary mass.

[0086] The insert 240 does not extend through the rear opening 230, and the club head 200 includes a badge 250 disposed within the rear opening 230 to close and / or seal the rear opening 230. With reference to FIGS. 8 and 9 , a recessed ledge 234 surrounds the rear opening 230. The recessed ledge 234 extends from the upper rear wall 222 into the rear opening 230 and provides a surface for connecting the badge 250. With reference to FIG. 1 , the insert outer surface 245 is recessed from the upper rear wall 222 so that the badge outer surface 255 can be flush with the upper rear wall 222. The insert outer surface 245 can be flush with the recessed ledge, and the badge 250 can be in intimate contact with the insert outer surface 245.

[0087] Badge 250 protects insert 240 during use. Accordingly, insert 240 may be formed of a material with a lower hardness and / or density than the insert 240 exposed on the exterior of club head 200. In some embodiments, insert 240 may have a hardness of less than Shore A 60, less than Shore A 50, less than Shore A 40, less than Shore A 30, less than Shore A 20, or less than Shore A 10. C. Rear opening on the heel side of the upper rear wall

[0088] FIG. 10 illustrates a club head 300, which is similar to the club heads 100 and 200 described above in that it includes a heel-side rear opening 330 and an insert 340. The club head 300 differs from the club heads 100 and 200 in that the heel-side rear opening 330 is located substantially at the heel. Specifically, the heel-side rear opening 330 extends across most of the heel side of the upper rear wall 322 but does not extend to the toe side of the upper rear wall 322. The heel-side rear opening 340 removes mass from the heel end 304 of the club head 300, allowing for more mass to be placed at the toe end 306 of the club head 300. This mass placement shifts the center of gravity (CG) position toward the toe, resulting in a draw-biased shot shape. Additionally, the heel-side rear opening 340 reduces mass at the top of the club head 300 to create discretionary mass, improving MOI and maintaining a low CG position.

[0089] As shown in FIG. 10, the rear opening 340 is 0.75 to 1.50 inches 2 For example, the exposed area may be 0.75 to 0.85 in 2 , 0.85~0.95in 2 , 0.95~1.05in 2 , 1.05~1.15in 2 , 1.15~1.25in 2 , or 1.25~1.50in 2 In some embodiments, the rear opening 340 may have an area of ​​approximately 0.81 in 2 The exposed area is .

[0090] 10, rear opening 330 may have an exposed area that is 30% to 80% of the surface area of ​​the upper rear wall. In some embodiments, rear opening 330 may form 30% to 45%, 45% to 65%, or 65% to 80% of the upper rear wall. In some embodiments, rear opening 330 forms approximately 43% of the area of ​​the upper rear wall.

[0091] As described above, club head 300 further includes insert 340 that completely fills internal cavity 307. Insert 340 has a shape that is complementary to the wall of the internal cavity, such that no voids are formed between insert 340 and club head body 301. Insert 340 has an insert outer surface 345 that is exposed through rear opening 340, and insert 340 forms a portion of the rear face of the club head. Specifically, insert 340 forms a portion of the rear face of the club head near heel 304, but does not form a portion of the rear face of the club head near toe 306. In this manner, insert 340 provides a multi-material solid club head structure that resembles the solid structure of a blade-style iron, but creates more discretionary mass. D. Heel and toe rear openings in the upper rear wall

[0092] FIG. 11 shows a club head 400, which is similar to the club heads 100, 200, and 300 described above in that it includes at least one rear opening and an insert. The club head 400 differs from the club heads 100, 200, and 300 in that it includes two rear openings. Specifically, the club head 400 includes a heel-side upper opening 430 and a toe-side upper opening 432. The heel-side upper opening 430 and the toe-side upper opening 432 are located on the upper rear wall 422 above the flex joint 425 and below the top rail 410. The heel-side upper opening 430 and the toe-side upper opening 432 are separated by a divider bar 449 that extends from the flex joint 425 toward the top rail 410. The divider bar 449 may be made of the same material as the rest of the body of the club head 400. The club head 400 with the heel-side upper opening 430 and the toe-side upper opening 432 allows for fine tuning of CG and mass properties to achieve desired performance and shot shape compared to other embodiments described herein.

[0093] As shown in FIG. 11, the heel-side upper opening 430 is 0.75 to 1.50 inches2 For example, the exposed area is 0.75 to 0.85 in 2 , 0.85~0.95in 2 , 0.95~1.05in 2 , 1.05~1.15in 2 , 1.15~1.25in 2 , or 1.25~1.50in 2 In some embodiments, the rear opening 340 may have an area of ​​approximately 0.81 in 2 The exposed area is .

[0094] As shown in FIG. 11, the toe-side upper opening 432 is 0.75 to 1.50 inches 2 For example, the exposed area is 0.75 to 0.85 in 2 , 0.85~0.95in 2 , 0.95~1.05in 2 , 1.05~1.15in 2 , 1.15~1.25in 2 , or 1.25~1.50in 2 In some embodiments, the rear opening 340 may have an area of ​​approximately 0.89 in 2 The exposed area is .

[0095] The heel-side upper opening 430 and the toe-side upper opening 432 are 1.300 to 1.900 inches in total. 2 For example, the total exposed area may be 1,300 to 1,400 in 2 , 1.400~1.500in 2 , 1.500~1.600in 2 , 1.600~1.700in 2 , 1.700~1.800in 2 , or 1,800 to 1,900 inches 2 In some embodiments, the total exposed area is about 1.45 in 2 is.

[0096] Heel-side upper opening 430 and toe-side upper opening 432 may have a combined exposed area that is 20% to 50% of the total surface area of ​​rear wall 416. In some embodiments, heel-side upper opening 430 and toe-side upper opening 432 form 20% to 25%, 25% to 30%, 30% to 35%, 35% to 40%, 40% to 45%, or 45% to 50% of the total surface area of ​​rear wall 416. For example, in some embodiments, heel-side upper opening 430 and toe-side upper opening 432 form approximately 35% of the total surface area of ​​rear wall 416.

[0097] The divider bar 449 has a width measured generally in the heel-toe direction. The width of the divider bar 449 can be between 0.05 inches and 0.20 inches. In some embodiments, the width of the divider bar 449 can be between 0.05 and 0.10 inches, between 0.10 and 0.15 inches, or between 0.15 and 0.20 inches. In some embodiments, the divider bar 449 has a width of approximately 0.11 inches.

[0098] Club head 400 further includes an insert 440 that completely fills internal cavity 407 and is exposed through heel-side upper opening 430 and toe-side upper opening 432. Insert 440 further includes a heel-side outer surface 445 and a toe-side outer surface 447, each of which forms a portion of the rear surface of the club head. In the illustrated embodiment, divider bar 449 is flush with insert's toe-side outer surface 447 but offset from insert's heel-side outer surface 445. In the illustrated embodiment, insert's heel-side outer surface 445 is recessed inward from divider bar 449. This surface arrangement around the divider bar results in a unique and aesthetically pleasing appearance while providing a multi-material solid club head structure that resembles the solid structure of a blade-style iron, but creates more discretionary mass. E. Heel-side rear opening, toe-side rear opening, and central rear opening in the upper rear wall

[0099] FIG. 12 shows a club head 500, which is similar to the club head 400 described above in that it includes multiple rear openings and an insert 540. The club head 500 differs from the club head 400 in that it includes three rear openings. Specifically, the club head 500 includes a heel-side upper opening 530, a toe-side upper opening 532, and a central opening 533. The heel-side upper opening 530, the toe-side upper opening 532, and the central opening 533 are each located in the upper rear wall 522 above the flex joint 525 and below the top rail 510. The heel-side upper opening 530 is located closer to the heel than the central opening 533 and is separated from the central opening 533 by a heel-side divider bar 546. Similarly, the toe-side upper opening 530 is located closer to the toe than the central opening 533 and is separated from the central opening 533 by a toe-side divider bar 549. Each of the divider bars 546, 549 extends from the flex joint 525 toward the top rail 510. The divider bars 546, 549 form part of the upper rear wall 522.

[0100] As shown in FIG. 12 , central opening 533 and toe-side opening 532 have larger exposed areas than heel-side opening 530. Central opening 533 has larger exposed areas than toe-side opening 532. In other embodiments, the relative exposed areas of openings 530, 532, and 533 may be different. For example, in some embodiments, central opening 533 may have the smallest exposed area or the second smallest exposed area compared to the other openings. In some embodiments, heel-side opening 530 may have the largest exposed area or the second largest exposed area compared to the other openings. In some embodiments, toe-side opening 532 may have the largest exposed area or the smallest exposed area compared to the other openings.

[0101] As shown in FIG. 12, the heel-side upper opening 530 is 0.5 to 1.25 inches 2 For example, the exposed area is 0.5 to 0.65 in 2 , 0.65~0.85in2 , 0.85~1.05in 2 , 1.05~1.15in 2 , or 1.15~1.25in 2 In some embodiments, the heel side upper opening 530 may have an area of ​​approximately 0.61 in 2 The exposed area is .

[0102] As shown in FIG. 12, the toe-side upper opening 532 is 0.5 to 1.25 inches 2 For example, the exposed area is 0.5 to 0.65 in 2 , 0.65~0.85in 2 , 0.85~1.05in 2 , 1.05~1.15in 2 , or 1.15~1.25in 2 In some embodiments, the toe side upper opening 532 may have an area of ​​about 0.88 in 2 The exposed area is .

[0103] As shown in FIG. 12, the central opening 533 is 0.5 to 1.25 inches 2 For example, the exposed area is 0.5 to 0.65 in 2 , 0.65~0.85in 2 , 0.85~1.05in 2 , 1.05~1.15in 2 , or 1.15~1.25in 2 In some embodiments, the central opening 533 may have an area of ​​about 0.95 in 2 The exposed area is .

[0104] The heel-side upper opening 530, the toe-side upper opening 532, and the central opening 533 are 1.300 to 1.900 inches in total. 2 For example, these openings may have a total exposed opening area of ​​1.300 to 1.400 in 2 , 1.400~1.500in 2 , 1.500~1.600in 2 , 1.600~1.700in 2 , 1.700~1.800in2 , or 1,800 to 1,900 inches 2 In some embodiments, these openings may have an area of ​​about 1.42 in 2 The exposed area is .

[0105] The heel-side divider bar 546 and the toe-side divider bar 549 have widths measured generally in the heel-toe direction. The widths of the divider bars 546, 549 can be between 0.05 inches and 0.20 inches. In some embodiments, the divider bars 546, 549 can have widths between 0.05 and 0.10 inches, between 0.10 and 0.15 inches, or between 0.15 and 0.20 inches. In some embodiments, the divider bars 546, 549 have a width of approximately 0.11 inches.

[0106] Club head 500 further includes an insert 540 that completely fills internal cavity 507 and is exposed through heel-side upper opening 530, toe-side upper opening 532, and central opening 533. Insert 540 further includes a plurality of outer surfaces, each of which forms a portion of the rear surface of the club head. Insert 540 defines a heel-side outer surface 545 that is exposed through heel-side upper opening 530, a toe-side outer surface 547 that is exposed through toe-side upper opening 532, and a central outer surface 548 that is exposed through central opening 533. Heel-side outer surface 545 forms a portion of the rear surface of the club head near heel 504 on upper rear wall 522. Toe-side outer surface 547 forms a portion of the rear surface of the club head near toe 506 on upper rear wall 522. Central outer surface 548 forms the portion of the club head's rear surface between heel outer surface 545 and toe outer surface 547 at upper rear wall 522. Each of insert's outer surfaces 545, 547, 548 may be flush with divider bars 546, 549 to form a continuous, smooth club head rear surface at upper rear wall 522. In this manner, insert 540 provides a multi-material solid club head structure that resembles the solid structure of a blade-style iron, but creates more discretionary mass. F. Rear opening in the lower rear wall

[0107] 13 illustrates a club head 600 that is similar to club heads 100, 200, 300, 400, and 500 in that it includes a rear opening and an insert. Club head 600 differs from club heads 100, 200, 300, 400, and 500 in that it includes a lower rear opening 630 instead of an upper rear opening. Lower rear opening 630 is located below flex seam 625 in the lower half of club head 600. Lower rear opening 630 allows for improved discretionary mass and mass properties to tune club head performance by eliminating high-density body material and replacing it with lower-density insert material.

[0108] The lower rear opening 630 is approximately 1.300 to 1.900 inches 2 For example, the lower rear opening 630 has an exposed opening area of ​​1.300 to 1.400 in 2 , 1.400~1.500in 2 , 1.500~1.600in 2 , 1.600~1.700in 2 , 1.700~1.800in 2 , or 1,800 to 1,900 inches 2 In some embodiments, the rear opening may have an exposed opening area of ​​about 1.620 in 2 The exposed area is .

[0109] Lower rear opening 630 has an open exposed area that is 20% to 50% of the total surface area of ​​rear wall 616. In some embodiments, lower rear opening 630 may form 20% to 25%, 25% to 30%, 30% to 35%, 35% to 40%, 40% to 45%, or 45% to 50% of the total surface area of ​​rear wall 616. For example, in some embodiments, lower rear opening 630 forms approximately 39% of the total surface area of ​​rear wall 616.

[0110] Club head 600 further includes an insert 640 that completely fills internal cavity 607 and is exposed through lower rear opening 630. Additionally, insert 640 includes an insert outer surface 645 that forms a portion of the rear surface of the club head. Specifically, insert 640 forms a portion of lower rear wall 624. The insert rear surface is flush with lower rear wall 624, forming a continuous, smooth outer surface. In this manner, insert 640 provides a multi-material solid club head structure that resembles the solid structure of a blade-style iron, but that creates more discretionary mass. G. Rear openings in the upper and lower rear walls

[0111] 14 and 15 show a club head 700, which is similar to the club heads 100-600 described above in that it includes a rear opening and an insert. The club head 700 differs from the club heads 100-600 in that it includes an upper rear opening 730 and a lower rear opening 732. A flex seam 725 separates the upper opening 730 and the lower opening 732, with the upper opening 730 located above the flex seam 725 and the lower opening 732 located below the flex seam 725.

[0112] The upper rear opening 730 is approximately 1.300 to 1.900 inches 2 For example, the upper rear opening 730 has an exposed opening area of ​​1,300 to 1,400 inches. 2 , 1.400~1.500in 2 , 1.500~1.600in 2 , 1.600~1.700in 2 , 1.700~1.800in 2 , or 1,800 to 1,900 inches 2 In some embodiments, the rear opening may have an exposed opening area of ​​about 1.593 in 2 The exposed area is .

[0113] The lower rear opening 732 is 1.300 to 1.400 inches 2 , 1.400~1.500in2 , 1.500~1.600in 2 , 1.600~1.700in 2 , 1.700~1.800in 2 , or 1,800 to 1,900 inches 2 In some embodiments, the lower rear opening 730 has an exposed opening area of ​​approximately 1.620 in 2 The exposed area is .

[0114] The upper rear opening 730 and the lower rear opening 732 are 2.00 to 4.00 inches in total. 2 In some embodiments, the total exposed area is between 2.00 and 2.25 in 2 , 2.25~2.50in 2 , 2.50~2.75in 2 , 2.75~3.00in 2 , 3.00~3.25in 2 , 3.25~3.50in 2 , 3.50~3.75in 2 , or 3.75-4.00 inches 2 In some embodiments, the lower rear opening 730 may be approximately 3.12 in. 2 The exposed area is .

[0115] The upper and lower rear openings 730 and 732 together form 60% to 95% of the total rear wall surface area. In some embodiments, the upper and lower rear openings 730 and 732 may form 60% to 70%, 70% to 80%, or 80% to 95% of the total rear wall area. In some embodiments, the upper and lower rear openings 730 and 732 form approximately 81.2% of the total rear wall area.

[0116] Club head 700 further includes an insert 740 that completely fills internal cavity 707 and is exposed through lower rear opening 732 and upper rear opening 730. Insert 740 further includes upper insert outer surface 745 and lower insert outer surface 747, each of which forms a portion of club head rear wall 716. Upper insert outer surface 745 is flush with upper rear wall 722, and lower insert outer surface 747 is flush with lower rear wall 724, forming a continuous, smooth club head rear surface. In this manner, insert 740 provides a multi-material solid club head structure that resembles the solid structure of a blade-style iron, but creates more discretionary mass. H. Badged rear openings on the upper and lower rear walls

[0117] 16 shows club head 800, which is similar to club head 700 in that it includes upper and lower rear openings 830 and 832. Club head 800 differs from club head 700 in that it further includes upper and lower badges 850 and 852 that cover upper and lower rear openings 830 and 832, respectively. Because badges 850 and 852 protect insert 840, it is possible to form insert 840 from a lower hardness and / or density material, thereby increasing discretionary mass, without compromising the durability of insert 840.

[0118] The upper and lower rear openings 830, 832 include recessed ledges to which the upper and lower badges 850, 852 connect. The recessed ledges surround each of the openings 830, 832. The recessed ledges allow the badges 850, 852 to be flush with the upper and lower rear walls 822, 824, forming a continuous, smooth rear exterior surface. Additionally, the upper and lower badges 850, 852 may be flush with the insert 840. I. Upper rear opening and local insert

[0119] 17-21 illustrate various club heads 900, 1100, 1200 with one or more rear openings and an insert that partially fills the internal cavity. Rather than an embodiment with an insert that completely fills the internal cavity, providing an insert that only partially fills the internal cavity results in a club head structure with one or more spaces or voids. The spaces or voids may be formed between the insert and the body or within the insert itself. An insert that partially fills the internal cavity provides more discretionary mass while still providing a high level of vibration damping.

[0120] 17-19 illustrate a club head 900 with a localized insert 940 that partially fills the internal cavity 907. The localized insert 940 is configured to contact specific portions of the club head body 901 to target areas where vibrations are dominant. The localized insert 940 efficiently damps dominant vibrations without requiring significant mass to dampen the vibrations. Because the localized insert 940 specifically contacts the areas where vibrations are dominant, a large portion of the internal cavity 907 can be left empty without compromising sound or feel quality.

[0121] Many iron-type club heads, particularly hollow-body irons, often have dominant vibrations occurring near the top of the club head (i.e., near the top rail or near the top of the face and / or rear). FIGS. 17-19 show a club head 900 with an insert 940 configured to dampen vibrations occurring near the top rail 910 and / or near the top of the striking face 902. In some embodiments, the local insert 940 may be configured to contact the inner surface of the sole 912, the inner surface of the top rail 910, the inner surface of the striking face 902, the inner surface of the rear wall 916, or any combination thereof, to dampen vibrations occurring in other areas of the body 901.

[0122] 17, the club head 900 includes a rear opening 930 located in the upper rear wall 922. In some embodiments, the rear opening 930 may provide a substantial open exposed area. In some embodiments, the upper rear opening may be between 5 and 15 cm. 2 In some embodiments, the upper rear opening may have an exposed area of ​​5 cm 2 ~7cm 2 , 7cm 2 ~9cm 2 , 9cm 2 ~11cm 2 , 11cm 2 ~13cm 2 , or 13cm 2 ~15cm 2 In some embodiments, the exposed area of ​​the upper rear opening may be 5 cm 2 Over 6cm 2 Over 7cm 2 Over 8cm 2 Over 9cm 2 Over 10cm 2 Over 11cm 2 Over 12cm 2 Over 13cm 2 Over 14cm 2 The rear opening 930 may be greater than 0.75 inches. The inclusion of rear opening 930 may increase discretionary mass by 5 grams or more compared to a similar hollow body iron without a rear opening. Additionally, rear opening 930 reduces mass from upper rear wall 922, thereby lowering the CG height of club head 900. In many embodiments, club head 100 may have a CG ground height of less than 0.75 inches, less than 0.65 inches, less than 0.55 inches, less than 0.45 inches, less than 0.35 inches, or less than 0.25 inches.

[0123] With reference to FIG. 18 , the club head 900 includes a badge 950 covering the rear opening 930. The badge 950 may be similar to one or more of the badges described above. The badge 950 may be formed of a very lightweight material to maintain discretionary mass created by the rear opening 930. With reference to FIG. 19 , the upper rear wall 922 may define a recessed ledge 934 surrounding the periphery of the rear opening 930 and configured to receive the badge 950. The recessed ledge 934 may be recessed from the outer surface of the rear wall 916. The badge 950 may be connected to the recessed ledge 934 such that the badge 950 seals the rear opening 930.

[0124] Club head 900 further includes an insert 940 connected to badge 950 and partially filling internal cavity 907. As shown in FIGS. 18 and 19 , insert 940 may be sandwiched between striking face rear surface 915 and badge 950. In many embodiments, insert 940 includes an insert rear surface 944 connected to badge inner surface 953. In many embodiments, insert 940 extends from badge inner surface 953 through internal cavity 907 to striking face rear surface 915. In the illustrated embodiment, insert 940 may include an abutment surface 942 configured to contact striking face rear surface 915. Badge 950 and insert 940 may be positioned such that abutment surface 942 contacts striking face rear surface 915 at strategic locations to effectively dampen vibrations.

[0125] To achieve desired vibration characteristics and desired performance characteristics (i.e., ball speed, launch conditions, MOI, etc.) for the club head 900, the insert 940 may contact the striking face rear surface 915 in a manner that dampens vibrations without interfering with flexure of the striking face 902 (and therefore without reducing ball speed). The manner in which the insert 940 contacts the striking face 902 may be designed to dampen vibrations without providing excessive resistance to the striking face 902 as it flexes upon impact. The contact area between the insert 940 and the striking face 902, the contact location between the insert 940 and the striking face 902, and the amount of preload force the insert 940 applies to the striking face 902 each affect vibration dampening and the deflection of the striking face 902. For example, the greater the contact area between the insert 940 and the striking face 902, the greater the damping effect of the insert 940. However, the greater the contact area between the insert 940 and the striking face 902, the greater the resistance force on the striking face 902 upon impact, preventing deflection. In some embodiments, the insert 940 increases damping while reducing the contact area between the insert 940 and the striking face 902 and reducing the preload between the insert 940 and the striking face 902. Below, we describe alternative embodiments of insert 940 configurations that achieve a balance between vibration damping and deflection of the striking face.

[0126] In some embodiments, the abutment surface 942 of the insert 940 lightly contacts the striking face rear surface 915. In such embodiments, the insert can contact the striking face rear surface 915 without preloading the striking face 902. In such embodiments, the contact between the insert 940 and the striking face 902 allows the insert 940 to dampen unwanted vibrations without preventing the striking face 902 from deflecting. In another embodiment, the insert 940 can be compressed between the badge 950 and the striking face rear surface 915 such that the insert 940 preloads the striking face rear surface 915. In such embodiments, the insert 940 can also provide structural reinforcement to the striking face 902 in addition to vibration dampening. In such embodiments, the structural support provided by the insert 940 allows the striking face 902 to be thinner and more flexible, thereby indirectly increasing deflection under a large preload.

[0127] The contact between the insert 940 and the striking face rear surface 915 can be characterized by a contact surface area and a contact location. The insert 940 defines a contact area measured as the surface area of ​​the abutment surface 942 that contacts the striking face rear surface 915. Generally, the contact area may be reduced while still providing the desired vibration damping. In some embodiments, the insert 940 defines a contact area of ​​5 cm 2 ~7cm 2 , 7cm 2 ~9cm 2 , or 9 cm 2 ~12cm 2 In some embodiments, the contact area is 5 cm 2 Over 6cm 2 Over 7cm 2 Over 8cm 2 Over 9cm 2 Over 10cm 2 Over 11cm 2 Over 12cm 2 It may be beyond that.

[0128] The contact location (i.e., the location where the abutment surface 942 contacts the striking face rear surface 915) may be configured to provide efficient vibration damping. The contact location may correspond to the location of the dominant vibration experienced by the club head 900. By locating the abutment surface 942 at or near the location of the dominant vibration, the insert 940 can provide a large damping effect with a small contact area.

[0129] As mentioned above, many iron-type club heads have dominant vibrations occurring at the top rail and / or the upper portion of the striking face. In some embodiments, the contact surface 942 may contact the striking face 902 only above the geometric center 920. In many embodiments, the entire contact surface 942 may be located above the geometric center 920. Locating the contact surface 942 higher may target dominant vibrations near the top of the club head 900, providing significant damping without requiring a large contact area. In other embodiments, the contact surface 942 may contact other portions of the striking face 902, such as below the geometric center 920. Different club heads may have different dominant vibration locations, and the contact surface 942 may be positioned accordingly.

[0130] 18 , the contact location between the insert 940 and the striking face 900 may be very high above the striking face rear surface 915. In many embodiments, the entire contact surface area may be located above the geometric center 920 of the striking face 902. In other embodiments, 80% to 100% of the contact surface area may be located above the geometric center 920 of the striking face 902. In some embodiments, 80% to 85%, 85% to 90%, 90% to 95%, or 95% to 100% of the contact surface area may be located above the geometric center 920 of the striking face 902.

[0131] Positioning the insert 940 to correspond to the location of the dominant vibration reduces the mass of the insert 940 required to provide the desired damping effect. The closer the insert 940 is to the dominant vibration, the more efficient the damping effect, and therefore the less mass is required to provide the desired vibration response. The lower the mass of the insert 940, the more discretionary mass can be redistributed throughout the club head 900. In many embodiments, the insert 940 may be made of an extremely lightweight foam material, such as carbon foam. In many embodiments, the insert 940 has a mass between 0.5 grams and 10 grams. In many embodiments, the insert has a mass of less than 10 grams, less than 9 grams, less than 8 grams, less than 7 grams, less than 6 grams, less than 5 grams, less than 4 grams, less than 3 grams, less than 2 grams, less than 1 gram, or less than 0.5 grams. Providing a low-mass insert 940 is particularly important in embodiments targeting dominant vibrations that occur high in the club head 900. The low mass insert 940 allows for a lower CG position because the insert is located in the upper part of the internal cavity 907 compared to a high mass insert in the same location.

[0132] 18, the insert 940 only partially fills the internal cavity 907. In many embodiments, the insert 940 may fill 5-30% of the internal cavity volume. In many embodiments, the remaining portion of the internal cavity 907 not filled by the insert 940 may remain unfilled. In other embodiments, the remaining portion of the internal cavity 907 not filled by the insert 940 may be completely or partially filled with a filler material, such as an injectable polymeric material.

[0133] In some embodiments, the club head may include multiple rear openings, multiple badges covering the multiple rear openings, multiple inserts sandwiched between the badges and the rear surface of the striking face, or any combination thereof. In many embodiments, it may be advantageous to provide multiple inserts with abutment surfaces that contact the rear surface of the striking face at various locations. In such embodiments, the dominant vibrations occurring at specific locations may be more precisely controlled. J. Upper rear opening and grille insert

[0134] FIG. 20 illustrates a club head 1100 with a rear opening 1130 and an insert 1140 having a lattice structure. The lattice insert 1140 has a plurality of internal and / or external spaces or voids, which allows the lattice insert 1140 to reduce its mass compared to a solid insert without such spaces or voids. The lattice insert 1140 partially fills the internal cavity 1107, creating a non-solid, multi-material club head structure. The lattice insert 1140 provides a high level of damping while creating more discretionary mass compared to a solid insert.

[0135] The lattice insert 1140 may have an insert profile defined by the outermost periphery of the lattice insert 1140. While the lattice insert 1140 may have a profile that fills the entire internal cavity 1107, the lattice insert 1140 increases discretionary mass by providing an effective density that is lower than the insert material density. The lattice insert 1140 may fill a large portion of the internal cavity volume without contributing significant mass to the club head 1100. The lattice insert 1140 may be in contact with all of the interior surfaces that define the internal cavity 1107, effectively damping vibrations without contributing the same amount of mass to the club head 100 as a solid insert made of the same material would.

[0136] As described above, the lattice insert has an effective density that is lower than the insert material density. The effective density of the lattice insert 1140 is determined by comparing the insert material density to the percentage of the lattice insert profile that the insert material occupies. For example, if the insert material occupies only 50% of the lattice insert profile, the effective density of the lattice insert is 50% of the material density. In some embodiments, the effective density may be 5% to 80% of the material density. In some embodiments, the effective density may be 5% to 10%, 10% to 15%, 15% to 20%, 20% to 25%, 25% to 50%, 50% to 75%, or 60% to 80% of the material density.

[0137] In some embodiments, the effective density of the grid insert 1140 is 0.0375 g / cm 3 ~1.5g / cm 3 In some embodiments, the effective density of the grid insert 1140 may be between 0.0375 and 0.250 g / cm 3 , 0.250~0.500g / cm 3 , 0.500~0.750g / cm 3 , 0.750~1.000g / cm 3 , 1.000~1.250g / cm 3 , or 1.250~1.500g / cm 3 In some embodiments, the effective density of the grid insert 1140 may be 1.500 g / cm 3 Less than 1.450g / cm 3 Less than 1.400g / cm 3 Less than 1.350g / cm 3 Less than 1.300g / cm 3 Less than 1.250g / cm 3 Less than 1.200g / cm 3 Less than 1.150g / cm 3 Less than 1.100g / cm 3 Less than 1.050g / cm 3 Less than 1.00 g / cm 3 Less than 0.950g / cm 3 Less than 0.900g / cm 3Less than 0.850g / cm 3 Less than 0.800g / cm 3 Less than 0.750 g / cm 3 Less than 0.700g / cm 3 Less than 0.650g / cm 3 Less than 0.600g / cm 3 Less than 0.550g / cm 3 Less than 0.500g / cm 3 Less than 0.450g / cm 3 Less than 0.400g / cm 3 Less than 0.350g / cm 3 Less than 0.300g / cm 3 Less than 0.250 g / cm 3 Less than 0.200g / cm 3 Less than 0.150g / cm 3 Less than 0.100g / cm 3 Less than 0.050g / cm 3 Less than 0.040g / cm 3 Less than or equal to 0.039 g / cm 3 is less than.

[0138] 20 , the club head 1100 includes a rear opening 1130 formed in the upper rear wall 1122. The rear opening 1130 is similar to the rear opening 130 of the club head 100, in that the rear opening 1130 extends across the entire rear wall 1116 in the heel-to-toe direction. In other embodiments, the rear opening 1130 may extend across only a portion of the upper rear wall 1122, similar to the heel-side upper opening 330 of the club head 300.

[0139] As shown in FIG. 20 , rear opening 1130 is covered with badge 1150, concealing grille insert 1140 within interior cavity 1107. Badge 1150 not only protects grille insert 1140 from environmental damage, but also prevents dust from entering interior cavity 1107 through voids in grille insert 1140. Additionally, badge 1150 allows grille insert 1140 to be formed from an insert material having a lower density and / or hardness than would be required if grille insert 1140 were exposed through rear opening 1130.

[0140] 20 , the club head 1100 does not include an opening in the lower rear wall 1124. Similar to the club head 100 described above, the rear opening 1130 removes mass from the upper rear wall 1122 while not removing mass from the lower rear wall 1124, resulting in a low CG height for the club head 1100. In some embodiments, the club head 100 may have a CG ground height of less than 0.75 inches, less than 0.65 inches, less than 0.55 inches, less than 0.45 inches, less than 0.35 inches, or less than 0.25 inches.

[0141] 21 , the club head 1200 may include multiple openings, such as an upper rear opening 1230 located in the upper rear wall 1222 and a lower rear opening 1232 located in the lower rear wall 1224. In such an embodiment, the upper rear opening 1230 is covered by an upper badge 1250, and the lower rear opening 1232 is covered by a second badge 1252. By providing multiple openings, more mass is removed from the rear wall 1216, increasing discretionary mass. III. Other Factors - Weight

[0142] In some embodiments, the body may further include one or more weights and / or one or more weight ports. Referring again to FIGS. 1 and 2, the club head 100 may include a toe weight 199 located below the toe 106. The club head body 101 may include a toe weight port that accommodates the toe weight 199. In some embodiments, the toe weight port may be isolated from the internal cavity 107. In other embodiments, the toe weight port may include an opening to the internal cavity so that a filler material can be injected. In some embodiments, the golf club head may further include a tip weight configured to fit within the hosel 105.

[0143] The inclusion of a toe weight 199 and / or tip weight increases the perimeter weight of the club head 100, thereby increasing one or more of the MOI values ​​of the club head 100. In many embodiments, the discretionary mass provided by the insert may be redistributed to the tip weight and / or toe weight. Because the tip weight and toe weight 199 are located at the heel and toe ends of the club head 100, respectively, increasing the mass of the tip weight and / or toe weight 199 significantly increases Iyy.

[0144] It should be noted that while the toe weight 199 and tip weight are described and illustrated with reference to club head 100, the toe weight 199 and / or tip weight may also be applied to any embodiment of a club head with a rear opening and an insert, including any of the club head embodiments described above and / or shown in the associated figures, such as club heads 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, and / or 1200. Additionally, while a toe weight and / or tip weight may be shown in one or more figures for one or more embodiments described above, any of the embodiments described herein may not include a toe weight, may not include a tip weight, or may not include both. example I. Example 1: Mass Reduction Between a Club Head with a Rear Opening and Insert and a Blade-Style Club Head

[0145] The first example demonstrates the discretionary mass created by providing a club head with a rear opening and an insert that completely fills the internal cavity. Compared to a blade-style iron, the insert replaces the high-density body material with a lower-density insert material. The amount of discretionary mass created can be calculated by multiplying the volume of the insert by the difference between the body material density and the insert material density. In one embodiment, the insert adds approximately 3 cm 3 In one embodiment, the density of the insert material is about 1.3 g / cm 3 and the density of the body material is approximately 7.78 g / cm 3 Thus, replacing body material with the insert provides approximately 20 grams of discretionary mass. Redistributing the 20 grams of discretionary mass to the perimeter of the club head can increase Iyy by 7% to 12%. The multi-material solid construction of the exemplary club head provides a lot of discretionary mass that can be used to significantly increase forgiveness. II. Example 2: Performance Comparison Between a Club Head with a Rear Opening and Insert and a Blade-Style Club Head

[0146] Performance characteristics were compared between a first exemplary club head according to the present invention and a first control group club head. The first exemplary club head was similar to club head 100, described in detail above. The first exemplary club head included a body having an internal cavity and an insert completely filling the internal cavity. The first exemplary club head further included a rear opening in the upper rear wall, the upper rear opening exposing the insert and measuring 1.593 in , occupying 35% of the total surface area of ​​the rear wall. 2 The insert had an exposed area of ​​1.25 mm. The insert was formed of a TPU material having a hardness of Shore A 80. Hereinafter, the first exemplary club head will be referred to as the "TPU insert club head."

[0147] The first control group club head was a blade-style iron-type club head. The first control group club head had a solid body without any inserts, openings, or voids. The first control group club head was formed from a single material. Hereinafter, the first control group club head will be referred to as the "blade-style control group club head."

[0148] The automated performance test used a golf swing machine to capture club head performance data under typical conditions. Average carry distance was recorded and compared for each club head. Additionally, the performance test compared the accuracy of each club head by measuring and recording the area of ​​dispersion of the finishing location of each shot for a sample set of each club head. A club head with less dispersion is more predictable in the finishing location of a given golf shot, so a smaller dispersion area indicates a more accurate club head. The results of the performance test are shown in Table 1 below. Table 1 JPEG2025532145000002.jpg22170

[0149] The TPU insert clubheads showed a significant decrease in dispersion area compared to the blade-style control clubheads. The dispersion area of ​​the TPU insert clubheads was 24.7% less than that of the blade-style control clubheads. The TPU insert clubheads reduced dispersion while producing similar carry distances as the first control clubheads (a negligible 0.06% decrease).

[0150] Performance testing results showed that the TPU insert clubheads performed better than the blade-style control clubheads. The TPU insert clubheads were significantly more accurate (and therefore more forgiving) than the blade-style control clubheads while maintaining similar carry distances. The increased accuracy of the TPU insert clubheads can be attributed to the increased discretionary mass created by replacing the high-density solid material within the body of the blade-style control clubheads with the lightweight insert in the TPU insert clubheads. III. Example 3: CG Comparison Between a Club Head with a Rear Opening and Insert and a Hollow Body Club Head

[0151] Mass properties were compared between the TPU insert club head, the second exemplary club head, and the second control group club head. The second exemplary club head was the same as the TPU insert club head described above in Example 2, except for the insert material. The second exemplary club head included an insert formed of a TPE material and having a Shore A30 hardness. Hereinafter, the second exemplary club head will be referred to as the "TPE insert club head."

[0152] The second control club head was a hollow-body iron-type club head. The second control club head (hereinafter the "hollow-body control club head") had a body with a continuous rear wall enclosing an internal cavity, with no openings or inserts. Instead, the hollow-body control club head had 6 grams of injectable filler material within the internal cavity, in accordance with prior art hollow-body iron vibration damping techniques.

[0153] The CG location for each club head was measured and compared. Table 2 below shows the CG ground height and CG leading edge depth for each club head. Table 2 JPEG2025532145000003.jpg43170

[0154] As shown in Table 2, each of the TPU insert club heads and the TPE insert club heads demonstrated improved CG location. Both example club heads had a lower and more forward CG location compared to the hollow-body control club heads. As discussed above, a lower and more forward CG location is desirable in iron-type club heads to promote improved launch characteristics. The improved CG location of the example club heads was attributed to the inclusion of an upper rear opening in the rear wall. By providing an upper rear opening in the rear wall, rather than a continuous rear wall, mass is removed from the upper rear of the club head, thereby creating discretionary mass that can be placed lower and more forward in the club head. IV. Example 4: Performance Comparison Between a Club Head with a Rear Opening and Insert and a Hollow Body Club Head

[0155] Performance characteristics were compared between TPU insert club heads, TPE insert club heads, and hollow-body control club heads. These clubs were described above in Examples 2 and 3. Player performance tests were conducted to obtain performance data for the club heads under normal conditions. Tests involved multiple golfers hitting a representative number of shots with each club head. The average carry distances for each club head were recorded and compared. Additionally, the performance tests compared the accuracy of each club head by measuring and recording the dispersion area of ​​the finishing position of each shot for a sample set of each club head. As noted above, a smaller dispersion area indicates a more accurate club head. The results of the first player performance test are shown in Table 3 below. Table 3 JPEG2025532145000004.jpg65170

[0156] Each of the exemplary club heads demonstrated a significant reduction in dispersion area and comparable carry distances (within 0.5 yards) compared to the hollow-body control club heads. The dispersion area for the TPU insert club heads was 39.1% smaller than the hollow-body control club heads, and the dispersion area for the TPE insert club heads was 8.9% smaller than the hollow-body control club heads. Player performance testing results indicated that the exemplary club heads performed better than the hollow-body control club heads. The exemplary club heads were significantly more accurate than the hollow-body control club heads while producing comparable carry distances. This increased accuracy may be attributed to the exemplary club heads' multi-material solid construction. The solid construction allows the club head to flex more consistently at impact, resulting in more predictable ball flight characteristics. V. Example 5: Sound and Feedback Comparison Between a Clubhead with a Rear Opening and Insert and a Hollow Body Clubhead

[0157] Sound and feel characteristics were compared between the TPU insert club heads, TPC insert club heads, and hollow-body control club heads. These clubs were described above in Examples 2 and 3. Referring back to the player performance testing, participants were surveyed regarding the sound and feel of each club head. Participants were asked to rate each club head's feel on a scale of 1 to 5 in the following categories: 1) overall impact feel, 2) sound, and 3) overall satisfaction with the club head. A score of 5 represented the highest level of satisfaction, and a score of 1 represented the lowest level of satisfaction. The ratings were averaged and compared to determine whether participants preferred the sound and feel of the exemplary club heads or the hollow-body control club heads. The survey results for the TPU insert club heads, TPE insert club heads, and hollow-body control club heads are shown in Table 4 below. Table 4 JPEG2025532145000005.jpg31170

[0158] Participants preferred the sound and feel characteristics of the TPU insert and TPE insert clubheads over the hollow-body control clubheads. The TPU insert and TPE insert clubheads each received higher scores than the hollow-body control clubheads in all categories. Notably, participants rated the impact feel (considering both sound and feel) of the exemplary clubheads significantly higher than that of the hollow-body control clubheads. On average, participants rated the impact feel of the TPU insert clubheads 27% higher than that of the hollow-body control clubheads. Similarly, participants rated the impact feel of the TPE insert clubheads 17% higher than that of the hollow-body control clubheads.

[0159] The improved sound and feel of the TPU-insert and TPE-insert clubheads compared to the hollow-body control clubheads can be attributed to the inserts. The TPU-insert and TPE-insert clubheads featured inserts that completely filled the internal cavity. The inserts provided a high level of vibration damping by contacting all surfaces forming the internal cavity, resulting in a more desirable sound and feel response at impact. In contrast, the hollow-body control clubheads featured an injectable filler material that was locally placed within the internal cavity rather than an insert. The absence of an insert in the hollow-body control clubheads resulted in a lower degree of vibration damping. VI. Example 6: Modal Frequency Analysis of a Hollow Body Iron with Rear Opening and Localized Insert

[0160] The vibration response of an exemplary club head (hereinafter "fourth exemplary club head") with a rear opening and localized insert according to this example was compared to the vibration response of a third control group club head. The fourth exemplary club head had a 1.565 in 2 The fourth exemplary club head further included an upper rear opening having an exposed area of ​​1.263 in., a badge covering the upper rear opening, and a local insert connected to the badge. The local insert only partially filled the internal cavity and contacted the upper portion of the rear surface of the striking face. The fourth exemplary club head further included a 1.263 in. gap between the local insert and the striking face. 2 0.05, with 93% of the contact surface area located above the geometric center of the striking face. The third control club head was similar to the exemplary club head. This control club head also had a rear opening and a badge covering the rear opening, but no insert. The internal cavity of the third control club head was left empty.

[0161] The third control group club head exhibited a dominant frequency of 4638 Hz at the top of the striking face, while the fourth exemplary club head exhibited a dominant frequency of 7718 Hz at the same location. The dramatic increase in dominant frequency between the third control group club head and the fourth exemplary club head is associated with an acoustically pleasing high-pitched sound at impact, rather than a low, dull sound at impact. This comparison demonstrates that the exemplary club head, with its localized insert in contact with the top of the striking face, provided a significantly better vibration response.

[0162] Substitution of one or more claimed elements constitutes a rearrangement, not a repair. Furthermore, benefits, other advantages, and solutions to problems have been described with respect to particular embodiments. However, these benefits, advantages, solutions to problems, and any one or more elements that may cause or make more pronounced the benefits, advantages, or solutions, should not be construed as a critical, necessary, or essential feature or element of any or all of the claims unless such benefit, advantage, solution, or element is recited in the claims.

[0163] Furthermore, the embodiments and limitations disclosed herein are not available to the public under the dedication doctrine if those embodiments and / or limitations (1) are not expressly recited in the claims, and (2) are equivalent or potentially equivalent to the explicit elements and / or limitations recited in the claims under the doctrine of equivalents. term

[0164] Item 1: A golf club head, comprising: a body including a striking face having a geometric center, a sole, a top rail, a rear wall, a heel, a toe, and a hosel, the body at least partially enclosing an internal cavity, the rear wall including a rear opening, the rear opening providing fluid communication between an exterior of the club head and the internal cavity; and an insert disposed within the internal cavity, the insert completely filling the internal cavity, the insert and the body together forming a multi-material solid structure with no voids or spaces therebetween, the insert having an insert outer surface exposed to an exterior of the club head through the rear opening, the insert outer surface forming at least a portion of a rear surface of the club head, the insert having an insert exposed area which is a surface area of ​​the insert outer surface exposed to the exterior of the club head, the insert exposed area being 1.3 in 2 ~1.9in 2 wherein the rear wall defines a rear wall surface area, and the insert exposed area is 20% to 50% of the rear wall surface area.

[0165] Item 2: Insert is 2.0g / cm 3 Item 1. The golf club head according to item 1, comprising an insert density of less than 1 / 2.

[0166] Item 3: Insert is 10cm 3 Item 1. The golf club head according to item 1, having a volume exceeding .

[0167] Item 4: The golf club head of item 2, wherein the body has a body density, and the club head has an insert density ratio defined as the insert density divided by the body density, and the insert density ratio is less than 0.25.

[0168] Item 5: The golf club head according to item 1, wherein the outer surface of the insert is flush with the rear wall.

[0169] Clause 6: The golf club head of clause 1, wherein the insert produces greater than 15 grams of discretionary mass compared to a similarly shaped club head having a single material solid construction.

[0170] Clause 7: A golf club head, comprising: a body including a striking face having a geometric center, a sole, a top rail, a rear wall, a heel, a toe, and a hosel, the body at least partially enclosing an internal cavity, the rear wall including a rear opening, the rear opening providing fluid communication between an exterior of the club head and the internal cavity; and an insert disposed within the internal cavity, the insert completely filling the internal cavity, the insert and the body together forming a multi-material solid structure with no voids or spaces therebetween, the insert having an insert outer surface exposed to an exterior of the club head through the rear opening, the insert outer surface forming at least a portion of a rear surface of the club head, the insert having an insert exposed area which is a surface area of ​​the insert outer surface exposed to the exterior of the club head, the insert exposed area being 1.3 in 2 ~1.9in 2 a rear wall defining a rear wall surface area, an insert exposed area being 20% ​​to 50% of the rear wall surface area, and the insert having a uniform hardness, the uniform hardness of the insert exceeding Shore A60.

[0171] Item 8: Insert is 2.0g / cm 3 Item 8. The golf club head according to item 7, comprising an insert density of less than 1000 .mu.m.

[0172] Item 9: The golf club head of item 8, wherein the body has a body density, and the club head has an insert density ratio defined as the insert density divided by the body density, and the insert density ratio is less than 0.25.

[0173] Item 10: Insert is 10cm 3 Item 8. The golf club head according to item 7, having a volume exceeding .

[0174] Item 11: The golf club head of item 7, wherein the insert produces greater than 15 grams of discretionary mass compared to a similarly shaped club head having a single material solid construction.

[0175] Item 12: A golf club head, comprising: a body including a striking face having a geometric center, a sole, a top rail, a rear wall, a heel end, a toe end, and a hosel, the body at least partially enclosing an internal cavity, the rear wall including an upper rear opening, the upper rear opening providing fluid communication between an exterior of the club head and the internal cavity, the rear wall including a bend seam extending generally horizontally from the heel end to the toe end, the rear wall including an upper rear wall portion extending from the bend seam to the top rail and a lower rear wall portion extending from the bend seam to the sole, the upper rear opening being located at the upper rear wall portion, the upper rear opening being 1.3 in. 2 ~1.9in 2 and an insert disposed within the internal cavity, wherein the insert completely fills the internal cavity, the insert and the body together forming a multi-material solid structure with no voids or spaces therebetween, and the insert has an upper insert outer surface exposed to an exterior of the club head through the upper rear opening, the upper insert outer surface forming at least a portion of the rear surface of the club head.

[0176] Item 13: Insert is 2.0 g / cm 3 Item 13. The golf club head according to item 12, comprising an insert density of less than 1000 .mu.m.

[0177] Item 14: Insert is 10cm 3 Item 13. The golf club head according to item 12, having a volume exceeding .

[0178] Item 15: The golf club head of item 13, wherein the body has a body density, and the club head has an insert density ratio defined as the insert density divided by the body density, and the insert density ratio is less than 0.25.

[0179] Item 16: Further includes a lower rear opening located at the bottom of the rear wall, the lower rear opening being 1.3 in 2 ~1.9in 2Item 13. The golf club head according to item 12, comprising a lower rear opening exposed area of

[0180] Item 17: Upper and lower rear openings are 2.0 in. 2 ~4.0in 2 Item 17. The golf club head according to item 16, having a total open exposed area of

[0181] Item 18: A golf club head according to Item 16, wherein the insert has a lower insert outer surface exposed to the outside of the club head through the lower rear opening, the lower insert outer surface forming at least a portion of the rear surface of the club head.

[0182] Clause 19: Insert is 10cm 3 Item 13. The golf club head according to item 12, having a volume exceeding .

[0183] Clause 20: The golf club head of clause 12, wherein the insert produces greater than 15 grams of discretionary mass compared to a similarly shaped club head having a single material solid construction.

[0184] Item 21: A golf club head comprising: a striking face having a geometric center and a striking face rear surface; a body having a sole, a top rail, a rear wall, a heel, a toe, and a hosel, the body at least partially enclosing an internal cavity, the rear wall having a rear opening, the rear opening providing fluid communication between an exterior of the club head and the internal cavity, the rear wall having a concave ledge surrounding the rear opening; a badge; and an insert partially filling the internal cavity, the badge having an outer periphery connected to the concave ledge such that the badge at least partially closes the rear opening; the badge having an inner badge surface disposed toward the internal cavity and an outer badge surface opposite the inner badge surface and disposed toward an exterior of the club head; the insert having an insert abutment surface abutting the striking face rear surface and an insert rear surface connected to the inner badge surface, the insert abutment surface being entirely located above the geometric center of the striking face.

Claims

1. A golf club head, a body having a striking face with a geometric center, a sole, a top rail, a rear wall, a heel, a toe, and a hosel; the body at least partially enclosing an interior cavity; the rear wall includes a rear opening; the rear opening provides fluid communication between an exterior of the club head and the interior cavity; an insert disposed within the internal cavity; the insert completely fills the internal cavity; the insert and the body together form a multi-material solid structure with no voids or spaces therebetween; the insert has an insert outer surface exposed to the outside of the club head through the rear opening; the insert outer surface forms at least a portion of the rear surface of the club head; the insert has an insert exposed area defined as the surface area of ​​the insert outer surface exposed to the exterior of the club head; The exposed area of ​​the insert is 1.3 in ２ ~1.9 inches ２ and the rear wall defines a rear wall surface area; the insert exposed area is 20% to 50% of the rear wall surface area; Golf club head.

2. The insert has a resistance of 2.0 g / cm ３ with an insert density of less than The golf club head according to claim 1 .

3. The insert is 10 cm ３ With a volume exceeding The golf club head according to claim 1 .

4. the body having a body density; the club head comprises an insert density ratio defined as the insert density divided by the body density; The insert density ratio is less than 0.

25. The golf club head according to claim 2 .

5. the insert outer surface is flush with the rear wall; The golf club head according to claim 1 .

6. the insert produces greater than 15 grams of discretionary mass compared to a similarly shaped club head having a single material solid construction; The golf club head according to claim 1 .

7. A golf club head, a body having a striking face with a geometric center, a sole, a top rail, a rear wall, a heel, a toe, and a hosel; the body at least partially enclosing an interior cavity; the rear wall includes a rear opening; the rear opening provides fluid communication between an exterior of the club head and the interior cavity; an insert disposed within the internal cavity; the insert completely fills the internal cavity; the insert and the body together form a multi-material solid structure with no voids or spaces therebetween; the insert has an insert outer surface exposed to the outside of the club head through the rear opening; the insert outer surface forms at least a portion of the rear surface of the club head; the insert has an insert exposed area defined as the surface area of ​​the insert outer surface exposed to the exterior of the club head; The exposed area of ​​the insert is 1.3 in ２ ~1.9 inches ２ and the rear wall defines a rear wall surface area; the insert exposed area is between 20% and 50% of the rear wall surface area; the insert has a uniform hardness; the uniform hardness of the insert is greater than Shore A 60; Golf club head.

8. The insert has a resistance of 2.0 g / cm ３ with an insert density of less than The golf club head according to claim 7.

9. the body having a body density; the club head comprises an insert density ratio defined as the insert density divided by the body density; The insert density ratio is less than 0.

25. The golf club head according to claim 8.

10. The insert is 10 cm ３ With a volume exceeding The golf club head according to claim 7.

11. the insert produces greater than 15 grams of discretionary mass compared to a similarly shaped club head having a single material solid construction; The golf club head according to claim 7.

12. A golf club head, a body having a striking face with a geometric center, a sole, a top rail, a rear wall, a heel end, a toe end, and a hosel; the body at least partially enclosing an interior cavity; the rear wall includes an upper rear opening; the upper rear opening provides fluid communication between an exterior of the club head and the interior cavity; the rear wall includes a bend joint extending substantially horizontally from the heel end to the toe end; the rear wall includes a rear wall upper portion extending from the flex joint to the top rail and a rear wall lower portion extending from the flex joint to the sole; the upper rear opening is located at an upper portion of the rear wall; The upper rear opening is 1.3 in. ２ ~1.9 inches ２ the body having an upper rear open exposed area of an insert disposed within the internal cavity; the insert completely fills the internal cavity; the insert and the body together form a multi-material solid structure with no voids or spaces therebetween; the insert has an upper insert outer surface exposed to an exterior of the club head through the upper rear opening; the upper insert outer surface forms at least a portion of the rear surface of the club head; Golf club head.

13. The insert has a resistance of 2.0 g / cm ３ with an insert density of less than The golf club head of claim 12.

14. The insert is 10 cm ３ With a volume exceeding The golf club head of claim 12.

15. the body having a body density; the club head comprises an insert density ratio defined as the insert density divided by the body density; The insert density ratio is less than 0.

25. The golf club head of claim 13.

16. a lower rear opening located at a lower portion of the rear wall; The lower rear opening is 1.3 in. ２ ~1.9 inches ２ a lower rear opening exposed area of The golf club head of claim 12.

17. The upper rear opening and the lower rear opening are 2.0 in. ２ ~4.0 inches ２ having a total open exposed area of The golf club head of claim 16.

18. the insert has a lower insert outer surface exposed to an exterior of the club head through the lower rear opening; the lower insert outer surface forms at least a portion of the rear surface of the club head; The golf club head of claim 16.

19. The insert is 10 cm ３ With a volume exceeding The golf club head of claim 12.

20. the insert produces greater than 15 grams of discretionary mass compared to a similarly shaped club head having a single material solid construction; The golf club head of claim 12.

21. A golf club head, a striking face having a geometric center and a striking face rear surface, a body having a sole, a top rail, a rear wall, a heel, a toe, and a hosel; the body at least partially enclosing an interior cavity; the rear wall includes a rear opening; the rear opening provides fluid communication between an exterior of the club head and the interior cavity; the body, the rear wall including a recessed ledge surrounding the rear opening; Badge and an insert partially filling the internal cavity; a periphery of the badge is connected to the recessed ledge such that the badge at least partially closes the rear opening; the badge has an inner badge surface disposed toward the internal cavity and an outer badge surface opposite the inner badge surface and disposed toward an exterior of the club head; the insert includes an insert abutment surface that abuts the striking face rear surface and an insert rear surface that is connected to the badge inner surface; the entire insert abutment surface is located above the geometric center of the striking face; Golf club head.

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