Golf club head with weighted pneumatic insert

Abstract

Golf club heads have weighted pneumatic inserts to improve mass properties and resulting performance characteristics. The weighted pneumatic insert comprises a membrane enclosing a hollow chamber that is filled with pressurized gas. The weighted pneumatic insert further comprises a weight receptacle that secures a weight to the membrane to influence the mass properties of the golf club head, such as the CG location. The weighted pneumatic insert damps undesirable vibrations and allows for CG personalization post-manufacturing.

Description

CROSS REFERENCE PRIORITIES

[0001] This claims the benefit of U.S. Provisional Application No. 63 / 777,569, filed Mar. 25, 2025; U.S. Provisional Application No. 63 / 826,863, filed Jun. 19, 2025; and U.S. Provisional Application No. 63 / 842,645, filed Jul. 11, 2025, the contents of which are fully incorporated herein by reference.TECHNICAL FIELD

[0002] This disclosure relates generally to golf equipment and, more particularly, relates to iron-type golf club heads having pneumatic inserts with weight systems.BACKGROUND

[0003] Mass properties of a golf club head drive performance by shaping the shot trajectory and providing forgiveness. Specifically, the center of gravity (CG) position and moment of inertia (MOI) directly affects launch angle and spin imparted to a golf ball. Slight changes in CG position and MOI can significantly impact a golf shot, such as by increasing or decreasing spin and / or lowering or raising launch angle. Mass pads are often integrated into the club head to change CG position and MOI. Integral mass pads, however, do not allow mass properties to be customized post-fabrication. Additionally, golf club manufacturers may use filler inserts and interchangeable weights to shift CG and change MOI, but these require heavy housing structures to ensure the durability of the inserts / weights are sufficient, thereby decreasing discretionary mass options.

[0004] Damping vibrational response after impact can improve the sound and feel of a golf club head. Inserts and filler materials generally improve vibrational response, but can negatively affect ball flight performance by creating undesirable weight distributions. Specifically, prior art inserts and filler materials are often solid materials, such as solid polymeric inserts, solid foam inserts, metallic inserts, or badges, that reduce discretionary mass. Robust retaining features and / or components, such as casings or mechanical fasteners are needed to secure the insert within the club head, further reducing discretionary mass.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] To facilitate further description of the embodiments, the following drawings are provided in which:

[0006] FIG. 1 is a front perspective view of a golf club head according to the present invention.

[0007] FIG. 2 is a front elevation view of the golf club head of FIG. 1.

[0008] FIG. 3 is a toe-side elevation view of the golf club head of FIG. 1.

[0009] FIG. 4 is a toe-side elevation view, in cross-section, of the golf club head of FIG. 1, with a pneumatic insert removed.

[0010] FIG. 5 is a front elevation view, in cross-section, of a hollow-body golf club head with a covered rear opening and a weighted pneumatic insert, according to the present invention.

[0011] FIG. 6 is a toe-side elevation view, in cross-section, of the golf club head of FIG. 5.

[0012] FIG. 7 is a front perspective view of the weighted pneumatic insert provided with the golf club head of FIG. 5.

[0013] FIG. 8 is a front perspective view of the weighted pneumatic insert of FIG. 7, with multiple pin weights removed.

[0014] FIG. 9 is a perspective view of one of the pin weights used in the weighted pneumatic insert of FIG. 7.

[0015] FIG. 10 is a front elevation view, in cross-section, of a golf club head comprising an alternative weighted pneumatic insert with pin weights.

[0016] FIG. 11 is a front, perspective view of the alternative weighted pneumatic insert of FIG. 10.

[0017] FIG. 12 is a front perspective view of a weighted pneumatic insert comprising a clamp weight, usable with any of the golf club heads disclosed herein.

[0018] FIG. 13 is a front perspective view of the weighted pneumatic insert of FIG. 12, with the clamp weight removed.

[0019] FIG. 14 is a side elevation view of the weighted pneumatic insert of FIG. 12.

[0020] FIG. 15 is a front perspective view of a weighted pneumatic insert comprising multiple clamp weights, usable with any of the golf club heads disclosed herein.

[0021] FIG. 16 is a front perspective view of a weighted pneumatic insert comprising a slidable weight, usable with any of the golf club heads disclosed herein.

[0022] FIG. 17 is a front perspective view of the weighted pneumatic insert of FIG. 16, with the slidable weight removed.

[0023] FIG. 18 is a perspective view of the slidable weight, usable with the weighted pneumatic insert of FIG. 17.

[0024] FIG. 19 is a front perspective view of the weighted pneumatic insert of FIG. 17, provided with an elongate bar weight.

[0025] FIG. 20 is a perspective view of the elongate bar weight of FIG. 19 removed from the weighted pneumatic insert.

[0026] FIG. 21 is a front elevation view, in cross-section, of a golf club head comprising a weighted pneumatic insert, according to the present invention.

[0027] FIG. 22 is a front perspective view of the weighted pneumatic insert comprising an elongate bar weight, used with the golf club head of FIG. 21.

[0028] FIG. 23 is a toe-side elevation view, in cross-section, of the weighted pneumatic insert of FIG. 22.

[0029] FIG. 24 is a front perspective view of a weighted pneumatic insert comprising a keyhole weight, usable with any of the golf club heads disclosed herein.

[0030] FIG. 25 is a front perspective view of the weighted pneumatic insert of FIG. 24, with the keyhole weight removed.

[0031] FIG. 26 is a rear perspective view of the weighted pneumatic insert of FIG. 24.

[0032] FIG. 27 is a rear perspective view of the weighted pneumatic insert of FIG. 24, with the keyhole weight removed.

[0033] FIG. 28 is a front perspective view of the keyhole weight of the weighted pneumatic insert of FIG. 24.

[0034] FIG. 29 is a front perspective view of another embodiment of a weighted pneumatic insert, according to the present invention.

[0035] FIG. 30 is a front perspective view of a one-sided keyhole weight usable with the weighted pneumatic insert of FIG. 29.

[0036] For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. The same reference numerals in different figures denote the same elements.DEFINITIONS

[0037] The terms “first,”“second,”“third,”“fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that comprises a list of elements is not necessarily limited to those elements but may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus.

[0038] The terms “left,”“right,”“front,”“back,”“top,”“bottom,”“over,”“under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.

[0039] The terms “couple,”“coupled,”“couples,”“coupling,” and the like should be broadly understood and refer to connecting two or more elements or signals, electrically, mechanically and / or otherwise, directly or indirectly.

[0040] FIGS. 1-3 schematically illustrate various embodiments of an iron-type golf club head 100 in various views. The club head 100 comprises a club head body 101 and a hosel 105. The club head body 101 can comprise a front 108 defining a strike face 102, a top rail 110, a sole 112 opposite the top rail 110, a heel 104, and a toe 106 opposite the heel 104. The club head 100 further comprises a rear 111 defining a rear wall 116 opposite the front 108. The top rail 110, sole 112, heel 104 and toe 106 extend rearward from the strike face perimeter toward the rear 111. The rear wall 116 extends upward from the sole 112 at the rear 111.

[0041] In some embodiments, the body material can be a stainless steel, such as 17-4 stainless steel. In other embodiments, the body material can be a titanium, titanium alloy, aluminum, bronze, 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 can comprise a density between 4.0 g / cm3 and 10.0 g / cm3. In some embodiments, the body material can comprise a density between 4.0 g / cm3 and 4.5 g / cm3, between 4.5 g / cm3 and 5.0 g / cm3, between 5.0 g / cm3 and 5.5 g / cm3, between 5.5 and 6.0 g / cm3, between 6.0 and 6.5 g / cm3, between 6.5 and 7.0 g / cm3, 7.0 g / cm3 and 7.5 g / cm3, between 7.5 and 8.0 g / cm3, between 8.0 and 8.5 g / cm3, between 8.5 and 9.0 g / cm3, between 9.0 and 9.5 g / cm3, or between 9.5 and 10.0 g / cm3.

[0042] In some embodiments, the strike face is formed as an integral part of the body, such as by unitary casting. In other embodiments, the club head can comprise a separately formed and attached faceplate that forms part or all of the strike face. The faceplate can be coupled to the body via welding or any other suitable means. The faceplate can be formed from a similar or different material than the body material. In some embodiments, the faceplate material can be a higher strength material (in terms of Young's Modulus) than the body material, such as C300. In other embodiments, the faceplate material can be a high-strength steel or steel alloy, such as C250, C350, AerMet® 100, AerMet® 310, AerMet® 340, HSR300, K300 or any other high-strength material suitable of being formed into a faceplate. In some embodiments, the faceplate material comprises a Young's Modulus of 180 Gpa to 205 Gpa.

[0043] Referring now to FIG. 4, the iron-type golf club head 100 further comprises a cavity 125 at least partially enclosed by the club head body 101 and defined by a body interior surface 103. Interior surfaces of the strike face 102, the top rail 110, the sole 112, the rear wall 116, the heel 104, and / or the toe 106 can at least partially define one or more cavity walls forming the boundary of the interior cavity 125. For example, the club head 100 includes a strike face interior surface 115, a top rail interior surface 119, a sole interior surface 121, a rear wall interior surface 123, a heel interior surface 122, and / or a toe interior surface 124 which cooperate to form the body interior surface 103 that defines the cavity 125. In the illustrated embodiment of FIG. 4, the rear wall 116 extends all the way from the sole 112 to the top rail 110, thereby enclosing the hollow interior cavity 125 in combination with the remainder of the body 101. Such embodiments can be referred to as a “fully enclosed hollow-body” club head.

[0044] In other embodiments, the rear wall 116 can extend only partially between the sole 112 and the top rail 110 and forms a rear opening that fluidly communicates between the cavity 125 and an exterior of the club head. In some embodiments, the rear opening is uncovered, thereby creating an open cavity exposed to the club head exterior. Such embodiments can be referred to as a “cavity-back” club head. In other embodiments, the rear opening can be covered by a badge, cover, and / or other member, whereby the rear wall and said covering member combine to enclose a hollow interior cavity. In such embodiments, the club head can be referred to as a “capped hollow-body” club head.

[0045] In some embodiments, the badge (or cover) can be formed of a lightweight metal material, including, but not limited to, aluminum or an aluminum alloy. In other embodiments, the badge can comprise a lightweight polymer, a plastic material, or a composite material. In some embodiments, the badge is constructed from multiple materials. In some embodiments, the badge comprises a density less than the density of the club head body. The badge material density may range from 0.8 to 3.0 g / cm3.

[0046] Any of the weighted pneumatic insert embodiments described herein can be applied to any of the open cavity and / or hollow interior cavity embodiments described herein. The term “cavity” as used herein, unless otherwise specified, can refer to a hollow interior cavity, enclosed either entirely or partially by the club head body, or an open cavity that fluidly communicates with the exterior of the club head. The term “cavity-back” can refer to a club head comprising an open cavity with an uncovered rear opening. The term “fully enclosed hollow-body” can refer to a club head comprising a hollow interior cavity that is fully or substantially enclosed by the club head body.

[0047] The term “strike face perimeter,” as used herein, can refer to an edge of the strike face. The strike face perimeter can be located along an outer edge of the strike face where the curvature deviates from a bulge and / or roll of the strike face.

[0048] The term “geometric centerpoint,” or “geometric center” of the strike face, as used herein, can refer to a geometric centerpoint of the strike face perimeter, and at a midpoint of the face height of the strike face. In the same or other examples, the geometric centerpoint also can be centered with respect to an engineered impact zone, which can be defined by a region of grooves on the strike face. As another approach, the geometric centerpoint of the strike face can be located in accordance with the definition of a golf governing body such as the United States Golf Association (USGA).

[0049] Physical characteristics of the club head 100 can be described relative to reference points defined by the club head 100 or surrounding environment. For example, as illustrated in FIGS. 2 and 3, the club head 100 can define a primary coordinate system centered about the strike face geometric center 120. The primary coordinate system can comprise an X-axis 1040, a Y-axis 1050, and a Z-axis 1060. The X-axis 1040 can extend in a heel-to-toe direction, and is parallel to the ground plane 1010. The X-axis 1040 can be positive towards the heel 104 and negative towards the toe 106. The Y-axis 1050 can extend in a top rail-to-sole direction and is orthogonal to both the ground plane 1010 and the X-axis 1040. The Y-axis 1050 can be positive towards the top rail 110 and negative towards the sole 112. The Z-axis 1060 can extend in front-to-rear direction and is parallel to the ground plane 1010 and orthogonal to both the X-axis 1040 and the Y-axis 1050. The Z-axis 1060 can be positive towards the strike face 102 and negative towards the rear end 111.

[0050] The primary coordinate system, as described herein, defines an XY plane extending through the X-axis 1040 and the Y-axis 1050. The coordinate system defines an XZ plane extending through the X-axis 1040 and the Z-axis 1060. The coordinate system further defines a YZ plane extending through the Y-axis 1050 and the Z-axis 1060. The XY plane, the XZ plane, and the YZ plane are all perpendicular to one another and intersect at the coordinate system origin located at the strike face geometric center 120. In these or other embodiments, the golf club head 100 can be viewed from a front view when the strike face 102 is viewed from a direction perpendicular to the XY plane. Further, in these or other embodiments, the golf club head can be viewed from a side view or side cross-sectional view when the heel 104 is viewed from a direction perpendicular to the YZ plane.

[0051] Further, referring to FIG. 2, the iron-type golf club head 100 can comprise a scoring area occupied by a plurality of score lines 117. The scoring area comprises a scoring area heel-side boundary plane 1020 tangent to the heel-most extent of the plurality of score lines 117 and a scoring area toe-side boundary plane 1025 tangent to the toe-most extent of the plurality of score lines 117. The scoring area heel-side boundary plane 1020 and the scoring area toe-side boundary plane 1025 each extend parallel to the YZ plane. The scoring area is bounded by the scoring area heel-side boundary plane 1020, the scoring area toe-side boundary plane 1025, and the strike face perimeter.

[0052] The term “ground plane,” as used herein, can refer to a reference plane associated with the surface on which a golf ball is placed. The ground plane can be a horizontal plane tangent to the sole at an address position.

[0053] The term “loft plane,” as used herein, can refer to a reference plane that is tangent to the geometric centerpoint of the strike face.

[0054] The term “loft angle,” as used herein, can refer to an angle measured between the loft plane and the XY plane (defined below).

[0055] The term “face height,” as used herein, can refer to a distance measured parallel to loft plane between a top end of the strikeface perimeter and a bottom end of the strikeface perimeter.

[0056] The term “lie angle,” as used herein, can refer to an angle between a hosel axis, extending through the hosel, and the ground plane. The lie angle is measured from a front view.

[0057] The “depth” of the golf club head, as described herein, can be defined as a front-to-rear dimension of the golf club head.

[0058] The “height” of the golf club head, as described herein, can be defined as a top rail-to sole dimension of the golf club head. In many embodiments, the height of the club head can be measured according to a golf governing body such as the United States Golf Association (USGA).

[0059] The “length” of the golf club head, as described herein, can be defined as a heel-to-toe dimension of the golf club head. In many embodiments, the length of the club head can be measured according to a golf governing body such as the United States Golf Association (USGA).

[0060] The “face height” of the golf club head, as described herein, can be defined as a height measured parallel to loft plane between a top end of the strike face perimeter near the top rail and a bottom end of the strike face perimeter near the sole.

[0061] The “geometric center height” of the fairway-type golf club head, as described herein, is a height measured perpendicular from the ground plane to the geometric centerpoint of the golf club head.

[0062] The “leading edge” of the club head, as described herein, can be identified as the most sole-ward portion of the strike face perimeter.

[0063] A “thickness”, as described herein is the length of a line segment connecting two points on opposing surfaces oriented perpendicular to one of the points.

[0064] The “center of gravity” or “CG”160 of the club head, as described herein, can refer to the point at which the mass is centered within the club head. The term or phrase “center of gravity position” or “CG location” can refer to the location of the club head center of gravity (CG) with respect to the XYZ coordinate system, wherein the CG position is characterized by locations along the X-axis 1040, the Y-axis 1050, and the Z-axis 1060. The term “CGx” can refer to the CG location along the X-axis 1040, measured from the strike face geometric center 120. The term “CG height” can refer to the CG location along the Y-axis 1050, measured from the strike face geometric center 120. The term “CGY” can be synonymous with the CG height. The term “CG depth” can refer to the CG location along the Z-axis 1060, measured from the strike face geometric center 120. The term “CGz” can be synonymous with the CG depth.

[0065] The golf club head 100 further comprises a coordinate system centered about the center of gravity 160. The coordinate system comprises an X′-axis 1070, a Y′-axis 1080, and a Z′-axis 1090. The X′-axis 1070 extends in a heel-to-toe direction. The X′-axis is positive towards the heel 104 and negative towards the toe 106. The Y′-axis 1080 extends in a sole-to-top rail direction and is orthogonal to both the ground plane 1010 and the X′-axis 1040. The Y′-axis 1080 is positive towards the top rail 110 and negative towards the sole 112. The Z′-axis 1090 extends in a front-to-rear direction, parallel to the ground plane 1010 and orthogonal to both the X′-axis 1070 and the Y′-axis 1080. The Z′-axis 1090 is positive towards the strike face 102 and negative towards the rear end 111.

[0066] The term or phrase “moment of inertia” (hereafter “MOI”) can refer to a value derived using the center of gravity (CG) location. The MOI can be calculated assuming the club head includes the body and the hosel structure. The term “MOIxx” or “Ixx” can refer to the MOI measured about the X′-axis. The term “MOIyy” or “Iyy” can refer to the MOI measured about the Y′-axis. The term “MOIzz” or “Izz” can refer to the MOI measured about the Z′-axis. The MOI values MOIxx, MOIyy, and MOIzz determine how forgiving the club head is for off-center impacts with a golf ball.

[0067] The term “iron,” as used herein, can, in some embodiments, refer to an iron-type golf club head having a loft angle that is less than approximately 50 degrees, less than approximately 49 degrees, less than approximately 48 degrees, less than approximately 47 degrees, less than approximately 46 degrees, less than approximately 45 degrees, less than approximately 44 degrees, less than approximately 43 degrees, less than approximately 42 degrees, less than approximately 41 degrees, or less than approximately 40 degrees. Further, in many embodiments, the loft angle of the club head is greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, greater than approximately 20 degrees, greater than approximately 21 degrees, greater than approximately 22 degrees, greater than approximately 23 degrees, greater than approximately 24 degrees, or greater than approximately 25 degrees.

[0068] In many embodiments, such as for “game improvement irons”, the volume of the club head is less than approximately 65 cm3, less than approximately 60 cm3, less than approximately 55 cm3, or less than approximately 50 cm3. In some embodiments, the volume of the club head can be approximately 50 cm3 to 60 cm3, approximately 51 cm3-53 cm3, approximately 53 cm3-55 cm3, approximately 55 cm3-57 cm3, or approximately 57 cm3-59 cm3.

[0069] In many embodiments, such as for “player's irons”, the volume of the club head is less than approximately 45 cm3, less than approximately 40 cm3, less than approximately 35 cm3, or less than approximately 30 cm3. In some embodiments, the volume of the club head can be approximately 31 cm3-38 cm3 (1.9 cubic inches to 2.3 cubic inches), approximately 31 cm3-33 cm3, approximately 33 cm3-35 cm3, approximately 35 cm3-37 cm3, or approximately 37 cm3-39 cm3.

[0070] In some embodiments, the iron can comprise a total mass ranging between 180 grams and 260 grams, 190 grams and 240 grams, 200 grams and 230 grams, 210 grams and 220 grams, or 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.DESCRIPTION

[0071] Iron-type golf club heads having weighted pneumatic inserts are described herein. The weighted pneumatic insert can enhance the mass properties of numerous types of iron-type golf club heads, including, but not limited to, cavity-back, capped hollow-body, and fully enclosed hollow-body golf club heads. More specifically, the weighted pneumatic insert allows CG and MOI to be adjusted, even after the body has been fabricated. This CG / MOI adjustment tailors weighting characteristics depending on handicap, swing plane, and swing speed. The weighted pneumatic insert resides within the cavity of the golf club head and harbors one or more weights. The weighted pneumatic insert further comprises a membrane enclosing one or more hollow chambers. The membrane is constructed of a flexible, moldable, and / or formable material. The one or more hollow chambers are filled with pressurized gas. The gas can be an inert gas, nitrogen-based gas, or simply pressurized air. In effect, the membrane acts as a lightweight carrier that secures weights in various desirable locations within the cavity. As a result, the inserts partially or completely surround the weights with pressurized gas, thereby insulating the weights from contacting the body and / or reducing vibrations and noise after impact with a ball. Further details regarding the membrane, hollow chambers, and integration of pneumatic inserts into club heads are set forth on pages 5-12, paragraphs

[0121] -

[0173] , of U.S. Patent Publication 2024 / 0335709, the disclosure of which is incorporated herein by reference.

[0072] Generally referring to FIGS. 5-9, the membrane has a membrane front wall 286, membrane rear wall 288, and membrane side wall 287 that cooperate to enclose the hollow chamber 244. The membrane front wall 286 defines a membrane front exterior surface 246, which, in some embodiments, contacts a strike face interior surface 215. The membrane front exterior surface 246 is opposite a membrane front interior surface 236 facing the hollow chamber 244. Similarly, the membrane rear wall 288 defines a membrane rear exterior surface 248, which may contact the rear wall interior surface 223 of the golf club head. The membrane rear wall 288 further defines a membrane rear interior surface 238, facing the hollow chamber 244. The membrane side wall 287 continuously extends between the membrane front wall 286 and membrane rear wall 288 to form a membrane perimeter exterior surface 247 and a membrane perimeter interior surface 237. In some embodiments, a membrane top exterior surface 261, membrane bottom exterior surface 262, membrane heel exterior surface 263, and membrane toe exterior surface 264 smoothly transition between one another to form the membrane perimeter exterior surface 247.

[0073] The one or more weights can be frictionally and / or adhesively secured to the membrane. The one or more weights can be enclosed by the membrane and occupy a portion of the hollow chamber. In some embodiments, the weighted pneumatic insert comprises one or more receptacles, which are configured to retain one or more weights. In some embodiments, the one or more receptacles include receptacle walls extending from the membrane front exterior surface 246 to the membrane rear exterior surface 248, thereby defining apertures fluidly communicating between the membrane front exterior surface and membrane rear exterior surface. In some embodiments, the one or more receptacles form structural discontinuities on or within the membrane front wall, membrane rear wall, or membrane side wall. The structural discontinuities may be depressions, protrusions, folds, ridges, channels, or grooves within the walls of the membrane. In some embodiments, a web defines a receptacle. The web is formed by merging portions of the membrane front wall, membrane rear wall, and membrane side walls together. Accordingly, the one or more weights can be complementarily shaped to fit within the apertures, engage the structural discontinuities, or be placed along the webs defined by the one or more receptacles. In some embodiments, exterior surfaces of the weights are coterminous with the membrane walls, such that the one or more weights define a portion of a perimeter and / or membrane exterior surfaces. The one or more weights may also be recessed from the membrane walls and / or entirely encapsulated within the perimeter of weighted pneumatic insert.

[0074] The weights may be secured to the pneumatic insert at different locations to change the mass properties of the assembled club head. The weights for the pneumatic insert are designed to alter CG in any one or more of the top rail / sole, heel / toe, and front / rear directions. Moreover, the directional changes in mass distribution cause increases / decreases in IXY, IXZ, and / or IYZ, such that MOI can be tailored across any plane.

[0075] In some embodiments, the weighted pneumatic insert lowers club head CG, which can increase launch angle, leading to higher and more consistent shots for improving golfers. Alternatively, in some embodiments, the weighted pneumatic insert includes one or more weights that shift the CG towards the toe or heel of the golf club head, thereby biasing ball trajectories away from predominant miss directions of certain golfers. Accordingly, the weighted pneumatic insert allows adjustment of mass properties, post-fabrication of the club head, to achieve desired performance characteristics.

[0076] In some embodiments, an iron-type golf club head may include multiple weighted pneumatic inserts. The multiple weighted pneumatic inserts may accommodate placement of several weights into favorable locations in cavities. In some embodiments, the weighted pneumatic insert may conform to one or more internal surfaces of the golf club head to substantially fill the cavity. In some embodiments, the weighted pneumatic insert can be localized to a strategic, isolated position within the cavity.

[0077] The one or more weights can be formed from a metal or metal alloy, including steel, tungsten, nickel, or copper. In other embodiments, the one or more weights can comprise a resin mixed with one or more powdered metals. In such embodiments, the resin can be a thermoplastic elastomer, a thermoplastic polyurethane or another suitable resin. In some embodiments, the resin can be viscoelastic. In such embodiments, in addition to concentrating mass and improving club head mass properties, the weights can improve impact vibrations through both mass and viscoelastic damping.

[0078] In embodiments wherein the weight comprises a resin mixed with powdered metal, the powdered metal can comprise steel, stainless steel, tungsten, or another suitable metal. In some embodiments, the weight can comprise one powdered metal. In other embodiments, the weight can comprise a blend of multiple powdered metals. The weight can further comprise a percentage of powdered metal by volume. In some embodiments, the weight can comprise 0% to 50% powdered metal by volume. In some embodiments, the weight can comprise 0% to 10%, 10% to 20%, 20% to 30%, 30% to 40%, or 40% to 50% powdered metal by volume. For example, the weight can comprise 0%, 1%, 10%, 20%, 30%, 40%, or 50% powdered metal by volume.

[0079] In some embodiments, the one or more weights can each comprise a mass between 0.1 and 50 grams. In other embodiments, the one or more weights comprise a mass between 0.1 gram and 10 grams. In some embodiments, one or more weights can each comprise a mass greater than 0.1 grams, greater than 5 grams, greater than 10 grams, greater than 15 grams, greater than 20 grams, greater than 25 grams, greater than 30 grams, greater than 35 grams, greater than 40 grams, greater than 45 grams, or greater than 50 grams. In some embodiments, the mass is between 0 grams to 10 grams, 10 grams to 20 grams, 20 grams to 30 grams, 30 grams to 40 grams, or 40 grams to 50 grams.

[0080] The one or more weights can have a higher specific gravity than the membrane or a higher specific gravity than the club head body. In some embodiments, the weight can comprise a specific gravity between 0.5 and 20.0. In some embodiments, the weight can comprise a specific gravity greater than 0.5, greater than 1.0, greater than 2.0, greater than 3.0, greater than 4.0, greater than 5.0, greater than 6.0, greater than 7.0, greater than 8.0, greater than 9.0, greater than 10.0, greater than 11.0, greater than 12.0, greater than 13.0, greater than 14.0, greater than 15.0, greater than 16.0, greater than 17.0, greater than 18.0, greater than 19.0, or greater than 20.0.I. Embodiments of Weighted Pneumatic InsertsA. Pin Weight Pneumatic Insert

[0081] The golf club head 200 comprising a cavity 225 has one or more pin weight members 299 housed within the pneumatic insert 240, best shown in FIGS. 5-9. In some embodiments, the golf club head 200 may comprise a badge 250. The membrane 242 forms one or more discrete apertures 290 that extend through the pneumatic insert 240, from the membrane front exterior surface 246 to the membrane rear exterior surface 248. Each aperture 290 acts as a receptacle configured to receive a pin weight 299. Referring to FIG. 9, the pin weight 299 can comprise an hourglass shape comprising a pair of bulbs 292 and a neck 295 therebetween. The pin weight 299 can be installed with the pneumatic insert 240 in an uninflated or semi-inflated state. One or more pin weights 299 can be inserted into the one or more apertures 290. Subsequently, the pneumatic insert 240 can be inflated so the membrane 242 fills the space between the neck 295 and the bulbs 292. As such, the membrane 242 can secure the one or more pin weights 299 to the pneumatic insert 240 without the use of any additional adhesives or fasteners. However, in other embodiments, an additional adhesive or fastener can be used to further secure the pin weight 299 to the pneumatic insert 240.

[0082] The club head can comprise any suitable number of receptacles 297 and / or any suitable number of pin weights 299. In the embodiment illustrated in FIGS. 7 and 8, the pneumatic insert 240 includes three receptacles 297: a heel-side receptacle 297a, a toe-side receptacle 297b, and a center receptacle 297c therebetween. The heel-side receptacle 297a is configured to receive a heel-side pin weight 299a, the toe-side receptacle 299b is configured to receive a toe-side pin weight 299b, and the center receptacle 297c is configured to receive a center pin weight 299c. In the illustrated embodiment, the pin weights 299 are located near the membrane bottom exterior surface 262, thereby lowering the club head CG. In other embodiments, one or more receptacles 297 and one or more pin weights 299 can be located at any position within the pneumatic insert 240 to tailor the club head CG position, such as near the membrane top exterior surface 261, near the membrane bottom exterior surface 262, near the membrane heel exterior surface 264, near the membrane toe exterior surface 263, or near the center of the pneumatic insert 240.

[0083] The configuration of the receptacles 297 and pin weights 299 can achieve vary mass properties of the club head. In some embodiments, the respective pin weights 299 can comprise different densities and / or masses. In some embodiments, the pin weights 299 can be configured to concentrate mass towards the membrane heel exterior surface 264 and the membrane toe exterior surface 263, thereby increasing perimeter weighting and MOI. The heel-side pin weight 299a and the toe-side pin weight 299b can comprise a greater density and / or mass than the center pin weight 299c. In other embodiments, the center receptacle 297c can be empty such that club head comprises a heel-side pin weight 299a and a toe-side pin weight 299b, but no center pin weight 299c.

[0084] In other embodiments, the pin weights 299 can be configured concentrate mass towards the center of the pneumatic insert 240, thereby increasing ball speed and improving sound and feel at impact. The center pin weight 299c can comprise a greater density and / or mass than the heel-side pin weight 299a and the toe-side pin weight 299b. In other embodiments, the heel-side receptacle 297a and the toe-side receptacle 290b can be empty such that club head comprises a center pin weight 299c, but no heel-side pin weight 299a or toe-side pin weight 299b.

[0085] In other embodiments, the pin weights 299 can be configured to concentrate mass towards either the membrane toe exterior surface 263 (thereby imparting a fade bias at impact) or the membrane heel exterior surface 264 (thereby imparting a draw bias at impact). In some embodiments, to concentrate mass towards the membrane toe exterior surface 263, the toe-side pin weight 299b can comprise a greater density and / or mass than the heel-side pin weight 299a. Alternatively, in some embodiments, the heel side receptacle 297a can be empty such that there is a toe-side pin weight 299b, but no heel-side pin weight 299a. In other embodiments, to concentrate mass towards the membrane heel exterior surface 264, the heel-side pin weight 299a can comprise a greater density and / or mass than the toe-side pin weight 299b. Alternatively, in some embodiments, the toe side receptacle 297b can be empty such that there is a heel-side pin weight 299a, but no toe-side pin weight 299b. The location, number, density, and mass of the pin weight 299 can be customized or tailored to fit a particular player with a specific club head mass distribution. Furthermore, the myriad of possible pin weight 299 configurations allows fine MOI adjustment to selectively enhance forgiveness and spin characteristics.

[0086] A golf club head 300 having a pneumatic insert 340 with two pin weights 399 is shown in FIGS. 10 and 11. The membrane 342 forms two discrete receptacles 397 that extend through the pneumatic insert 340, from the membrane front exterior surface 346 to the membrane rear exterior surface 348. The two discrete receptacles 397 may include a heel-side receptacle 397a and a toe-side receptacle 397b, sized to accept pin weights 399, wherein a heel pin weight 399a is housed within the heel-side receptacle 397a and a toe pin weight 399b is housed within the toe-side receptacle 397b. As described above, the pin weights 399 can comprise an hourglass shape and may be installed with the pneumatic insert 340 in an inflated or semi-inflated state. Following installation, the pneumatic insert 340 can be inflated so that the membrane 342 applies pressure on the pin weights 399, such that they are secured within the two discrete receptacles 397, without the use of any additional adhesives or fasteners. However, in other embodiments, an additional adhesive or fastener can be used to further secure the pin weights 399 to the pneumatic insert 340.

[0087] The pin weights 399 can be used to achieve desired club head mass properties. Generally, the pin weights 399 are located near the membrane bottom exterior surface 362, which lowers the golf club head CG, but in other embodiments, the pin weights 399 may be located at any position within the pneumatic insert 340 to adjust club head CG position. In some instances, the pin weights 399 may be located near the membrane top exterior surface 361, near the membrane bottom exterior surface 362, near the membrane heel exterior surface 364, near the membrane toe exterior surface 363, or near the center of the pneumatic insert 340. Additionally, the two pin weights 399 may comprise different densities / masses that influence the club head CG location and performance. For instance, the heel pin weight 399a may have a higher mass than the toe pin weight 399b, which shifts the club head CG heelward and promotes a draw bias. Conversely, the toe pin weight 399b may have a higher mass than the heel pin weight 399a, which shifts the club head CG toeward and promotes a fade bias. The pin weights 399 further may adjust swing weight, which influences balance and perceived weight of the club.

[0088] The pneumatic insert 340 is shaped to fit within a lower portion of the cavity 325. The pneumatic insert 340 and the lower portion of the cavity 325 are substantially rectangular, as illustrated in FIG. 10. Additionally, the pneumatic insert 340 may comprise a wing 398, which protrudes from the main body of the pneumatic insert 340, in a heelward or toeward direction. The wing 398 may help locate the pneumatic insert 340 within the golf club head. Further, the wing 398 extends above either a heel-side mass pad 380a or a toe-side mass pad 380b. In some embodiments, the pneumatic insert 340 may comprise two wings 398 that extend above both the heel-side mass pad 380a and the toe-side mass pad 380b to provide additional damping and further locate the insert within the club head. Upon installation, the pneumatic insert 340 contacts the strike face interior surface 315 and the rear wall 316 to provide damping. In some embodiments, the golf club head may comprise a badge 350 and the membrane top exterior surface 361 may not contact a badge lower surface 352. In other embodiments, the membrane top exterior surface 361 may contact the badge lower surface 352. The pin weights 399 reside in the two discrete receptacles 397 such that they contact the strike face interior surface 315, but do not contact the rear wall 316. In some embodiments, the pin weights 399 may be recessed, such that they do not contact either the strike face interior surface 315 or the rear wall 316.B. Clamp Weight Pneumatic Insert

[0089] A weighted pneumatic insert 440 having a clamp weight 499 is illustrated in FIGS. 12-14. The clamp weight 499 attaches to the weighted pneumatic insert 440 by sandwiching against a portion of the membrane 442. For example, the membrane 442 may include a solid web 445 forming a localized area of the insert having a reduced thickness. An aperture 490 is formed in the web 445. The clamp weight 499 includes a front head 492, a rear head 494, and a bridge 495 therebetween. As illustrated in FIG. 14, the bridge 495 extends through the aperture 490, while the front head 492 and rear head 494 clamp against a web front surface and a web rear surface to secure the clamp weight 499 to the membrane 442. The web front surface is inset from the membrane front exterior surface 446, and the web rear surface is inset from the membrane rear exterior surface 448. In some embodiments, adhesive may be applied to the web front surface and / or web rear surface of web 445 further to secure the clamp weight 499 to the membrane.

[0090] The front head 492 and / or the rear head 494 can be coupled to the bridge 495 via mechanical or adhesive means. In some embodiments, the bridge 495 is integral with one of the heads (i.e., either the front head 492 or the rear head 494). During installation, the bridge 495 can be inserted through the aperture 490 and subsequently coupled to the other head, which may comprise receiving geometry complementary to the bridge 495. Once coupled, the front head 492 and the rear head 492 clamp against the web 445, thereby securing the clamp weight 499 to the membrane 442. In some embodiments, the entire clamp weight 499 can be an integral piece. In such an embodiment, the clamp weight 499 can be over molded with the membrane 442.

[0091] The web 445 can be a thin, pliable portion of the membrane 442 that acts as an appendage extending away from the chamber 444. The web 445 is ancillary to the chamber and thereby does not form any portion of the chamber. The web 445 can be located in any part of the pneumatic insert 440 to achieve a desired weight location. The web 445 may be formed by compressing together a portion of the membrane between the membrane front wall, membrane rear wall, and, in some embodiments, the membrane side wall. The web 445 may also be formed separately and attached to a desired portion of the membrane. As shown in FIG. 12, the clamp weight 499 is located in a bottom, toe-most corner of the pneumatic insert 440. The clamp weight 499 resides at the juncture of the membrane toe exterior surface 464 and the membrane bottom exterior surface 462. Further, as illustrated in FIG. 14, the front head 492 can be flush with the membrane front exterior surface 446 and the rear head 494 can be flush with the membrane rear exterior surface 448. This configuration concentrates mass near the sole and the toe, thereby lowering club head CG and imparting a fade bias at impact. Accordingly, an iron-type golf club head comprising the pneumatic insert 440 in this configuration may counteract hook misses and facilitate high launching shots.

[0092] The clamp weight 499 can be located at other positions on the insert to achieve desired mass properties. In some embodiments, the clamp weight 499 can located in a bottom, heel-most corner of the pneumatic insert 440, such that it resides at the juncture of the membrane heel exterior surface 463 and the membrane bottom exterior surface 462. In this configuration, the club head comprising the weighted pneumatic insert 440 may facilitate shots with high launch and draw bias. In other embodiments, the clamp weight 499 can be centered about the pneumatic insert 440, such that the clamp weight 499 is spaced in between the membrane toe exterior surface 464 and the membrane heel exterior surface 463. The center location of the clamp weight 499 can promote a neutral ball flight (i.e., with neither a draw bias nor a fade bias). The clamp weight 499 can be located near the membrane bottom exterior surface 462, the membrane top exterior surface 461, or anywhere therebetween to achieve any desired CG height. The clamp weight 499 can be placed in extreme positions within the cavity (i.e. near the heel or toe) to increase perimeter weighting and MOI.

[0093] In some embodiments, the front head 492 and the rear head 494 can be different densities and / or masses to further tailor club head mass distribution. In some embodiments, the front head 492 can comprise a greater mass and / or a greater density than the rear head 494, thereby decreasing the club head CG depth. In other embodiments, the front head 492 can comprise a lesser mass and / or a lesser density than the rear head 494, thereby increasing the club head CG depth.

[0094] In alternative embodiment, illustrated in FIG. 15, a weighted pneumatic insert 540 includes two clamp weights. More specifically, the insert comprises a toe-side clamp weight 599a and a heel-side clamp weight 599b. The toe-side clamp weight 599a resides at the juncture of the membrane toe exterior surface 564 and the membrane bottom exterior surface 562, whereas the heel-side clamp weight 599b resides at the juncture of the membrane heel exterior surface 563 and the membrane bottom exterior surface 562. This configuration concentrates mass into the low corners of the pneumatic insert 540, thereby lowering club head CG and increasing MOI through perimeter weighting. Accordingly, the club head facilitates higher launching and spinning shots, due to the enhanced perimeter weighting and forgiveness.

[0095] In some embodiments, the toe-side clamp weight 599a and the heel-side clamp weight 599b can be different densities and / or masses to further tailor club head mass distribution. In some embodiments, the toe-side clamp weight 599a can comprise a greater mass and / or a greater density than the heel-side clamp weight 599b, thereby concentrating mass toeward and imparting a fade bias at impact. In other embodiments, the heel-side clamp weight 599b can comprise a greater mass and / or a greater density than the toe-side clamp weight 599a, thereby concentrating mass heelward and imparting a draw bias at impact.

[0096] The toe-side clamp weight 599a and the heel-side clamp weight 599b can be located in any position or combination of positions described above. The location, density, and mass of each of the toe-side clamp weight 599a and the heel-side clamp weight 599b can be customized or tailored to fit a particular player with a specific club head mass distribution.C. Slidable Weight Pneumatic Insert

[0097] A weighted pneumatic insert 600 having a slidable weight 699 positionable at different locations along the same pneumatic insert 640 illustrated in FIGS. 16-18. Referring specifically to FIG. 18, the slidable weight 699 comprises an I-beam shape having a front head 692, a rear head 634 and a bridge 695 disposed therebetween. The pneumatic insert 640 comprises a receptacle 697 further comprising a web 645 that is recessed relative to the membrane front exterior surface 646 and the membrane rear exterior surface 648 to form a weight channel 696. In the illustrated embodiment, the weight channel 696 extends in a heel-to-toe direction between the membrane heel exterior surface 664 and the membrane toe exterior surface 663. In other embodiments, the weight channel 696 can extend in any other suitable direction, such as diagonally or between the membrane top exterior surface 661 and the membrane bottom exterior surface 662. The weight channel 696 is configured to receive the slidable weight 699. The slidable weight 699 can sit within the weight channel 696 such that the front head 692 is flush with the membrane front exterior surface 646 and the rear head 648 is flush with the membrane rear exterior surface 648.

[0098] An aperture 690 extends through the web 645, substantially following the path of the weight channel 696, as illustrated in FIG. 17. The bridge 695 can be integral with one of the heads (i.e., either the front head 692 or the rear head 694). During installation, the bridge 695 can be inserted through the aperture 690 and subsequently coupled to the other, non-integral head. Once coupled, the front head 692 and the rear head 694 clamp against the web 645, thereby securing the slidable weight 699 to the membrane 642. In some embodiments, the slidable weight 699 can be permanently coupled together, such as through adhesive coupling. In other embodiments, the slidable weight 699 can be releasably coupled together. In such embodiments, the slidable weight 699 location can be adjusted after initial assembly onto the membrane 642.

[0099] In some embodiments, the slidable weight 699 can be positionable at any location along the weight channel 696. In other embodiments, locking features may be included to secure the slidable weight 699 in discrete locations. Specifically, the web 645 can define one or more web retainers that define distinct positions along the weight channel 696 for positioning the slidable weight 699. In such embodiments, the slidable weight 699 can comprise corresponding weight retainers configured to engage the web retainers. In some embodiments, the web retainers can comprise one or more nubs or protrusions that extend into the aperture 690 or outward towards the membrane front exterior surface 646 or the membrane rear exterior surface 648. The weight retainers can comprise one or more recesses corresponding to the geometry of the web retainers. The weight retainers can be located on the bridge 695, the front head 692, the rear head 694, or a combination thereof. In other embodiments, the web retainers can be one or more notches disposed toward the aperture 690 or recesses extending into the outward-facing surfaces of the web 645. The weight retainers can comprise one or more protrusions corresponding to the geometry of the web retainers.

[0100] The configuration of the slidable weight 699 can achieve various desired mass properties. The slidable weight 699 can be positioned towards the membrane toe exterior surface 663 to impart a fade bias at impact, towards the membrane heel exterior surface 664 to impart a draw bias at impact, or towards the center of the pneumatic insert 640 to promote a neutral ball flight. In some embodiments, the front head 692 and the rear head 694 can be different sizes, densities, and / or masses to further tailor club head mass properties. In some embodiments, the front head 692 can comprise a greater mass and / or a greater density than the rear head 694, thereby decreasing the club head CG depth. In other embodiments, the front head 692 can comprise a lesser mass and / or a lesser density than the rear head 694, thereby increasing the club head CG depth. The slidable weight configuration can be customized or tailored to fit a particular player with a specific club head mass distribution.D. Elongate Bar Weight Pneumatic Insert

[0101] A weighted pneumatic insert 740 having an elongate bar weight 799 substantially filling the entire weight channel 796, is illustrated in FIGS. 19 and 20. In the illustrated embodiment, the elongate bar weight 799 spans the entire weight channel 796 from a weight channel heel end 796a to a weight channel toe end 797b. In contrast to the slidable weight 799, described above, the elongate bar weight 799 is fixedly disposed within the weight channel 796 at a single position. The elongate bar weight channel 796 can be substantially similar to the slidable weight channel 696, and the elongate bar weight 799 can be similar to the slidable weight 699 in that the elongate bar weight 799 comprises an I-beam shape having a front head 792, a rear head 794 and a bridge 795 disposed therebetween. In other embodiments, the elongate bar weight 799 may comprise a structure having thicker front head 792, rear head 794, and bridge 795, wherein the pneumatic insert is devoid of a web 745.

[0102] The pneumatic insert 740 comprises a receptacle 797 further comprising a web 745 and an aperture 790. Additionally, the bridge 795 is integral with one of the heads (i.e., either the front head 792 or the rear head 794). During installation, the bridge 795 is inserted through the aperture 790 and subsequently coupled to the other, non-integral head. Once coupled, the front head 792 and the rear head 794 clamp against the web 745, thereby securing the elongate bar weight 799 to the membrane 742. In some embodiments, the elongate bar weight 799 is permanently affixed within the receptacle 797, such as through adhesive coupling, welding, or mechanical fastening. In other embodiments, the elongate bar weight 799 is integrally formed with the pneumatic insert 740, such as through co-molding or casting.

[0103] An alternative embodiment of a weighted pneumatic insert 800 having an elongate bar weight 899, is illustrated in FIGS. 21-23. The pneumatic insert 840 comprises a receptacle 897 disposed inwardly from the membrane side wall 860. The receptacle 897 comprises a receptacle wall 898 extending from the membrane front exterior surface 846 to the membrane rear exterior surface 848, thereby defining an aperture 890. The aperture 890 fluidly communicates between the membrane front exterior surface 846 and the membrane rear exterior surface 848. The receptacle 897 is sized to receive the elongate bar weight 899, wherein the elongate bar weight 899 may comprise a shape that is obround, rectangular, elliptical, non-linear, or any other suitable shape. Similar to previous embodiments, the elongate bar weight 899 comprises a front head 892 and rear head 894 connected by a bridge 895. In this alternative embodiment, the front head 892, rear head 894, and bridge 895 may be formed integrally and is sized to be secured within the receptacle 897. Specifically, elongate bar weight 899 may comprise a bridge 895 that is thinner than the front head 892 and the rear head 894, such that the elongate bar weight 899 can be firmly housed by the receptacle 897, locking it in place. The receptacle 897 comprises a front weight opening 830 and a rear weight opening 831. The front weight opening 830 comprises a shape that substantially matches the shape of the front head 892 and the rear weight opening 831 may comprise a similar shape with equivalent or smaller dimensions.

[0104] As shown in FIG. 23, the aperture 890 of the pneumatic insert 840 is configured to receive the elongate bar weight 899 so that a weight front surface 852 is disposed at or proximate the front weight opening 830 and the weight rear surface 853 is disposed at or proximate rear weight opening 831. In many embodiments, the weight front surface 852 is flush with the membrane front exterior surface 846 and the weight rear surface 853 is inset from the membrane rear exterior surface 848. As described in previous embodiments, the elongate bar weight 899 can be installed in the pneumatic insert 840 while it is in an inflated or semi-inflated state. Following installation, the pneumatic insert 840 can be inflated so that the membrane 842 applies pressure on the elongate bar weight 899, such that they are secured within the receptacle 897, without the use of any additional adhesives or fasteners. However, in other embodiments, an additional adhesive or fastener can be used to further secure the elongate bar weight 899 to the pneumatic insert 840.

[0105] Each of the pneumatic inserts 740, 840 comprising elongate bar weights 799, 899 comprise a weight width 770, 870 defined by the linear distance between the heelward most point and the toeward most point of the elongate bar weight. Additionally, a weight height 772, 872 is defined as the linear distance between the soleward most point and the uppermost point of the elongate bar weight. In some embodiments, the weight width is larger than the weight height, so mass can be more evenly distributed across the pneumatic insert, which increases MOI and forgiveness. In other embodiments, the weight width may be approximately equal to the weight height, thereby concentrating more mass in the center of the pneumatic insert. Concentrating the more mass in the center of the pneumatic insert would lead to a golf club head with higher ball speed on center strikes. In alternative embodiments, the weight height may be larger than the weight width, which may result in a raised CG. Raising the CG leads to a lower launch angle and increased spin.

[0106] Because the elongate bar weight 799, 899 occupies the entire weight channel 796, 896, its position within the club head remains fixed after manufacture. The configuration of the elongate bar weight can be selected to achieve desired club head mass properties. In the illustrated embodiment, the elongate bar weight is located near the membrane bottom exterior surface to lower the club head CG position. For example, the elongate bar weight can be positioned towards the membrane toe exterior surface to impart a fade bias at impact, towards the membrane heel exterior surface to impart a draw bias at impact, or towards the center of the pneumatic insert to promote a neutral ball flight. In some embodiments, the front head and the rear head can be different sizes, densities, and / or masses to further tailor club head mass properties. In some embodiments, the front head can comprise a greater mass and / or a greater density than the rear head, thereby decreasing the club head CG depth. In other embodiments, the front head can comprise a lesser mass and / or a lesser density than the rear head, thereby increasing the club head CG depth. The elongate bar weight configuration can be customized during manufacture to fit a particular player with a specific club head mass distribution.

[0107] Performance characteristics and benefits can result from an elongate bar weight 799, 899 disposed within the pneumatic insert as a rectangular weight member. Namely, the benefits include improved golf club head sound and feel and more desirable golf club head mass properties. The rounded corners of the obround weight member can also improve weight member durability by alleviating stress concentrations that may otherwise build up in sharper corners. As such, golf club heads comprising pneumatic inserts housing obround weight members may be more resistant to wear than similar golf club heads with pneumatic inserts housing other weight members.E. Keyhole Pneumatic Inserts

[0108] In some embodiments, the pneumatic insert 940 can comprise a keyhole weight 999 disposed within a keyhole-shaped opening of a membrane 942, shown in FIGS. 24-28. Referring to FIG. 28, the keyhole weight 999 comprises a front head 992, a rear head 994, and a bridge 995 disposed therebetween. The rear head 994 may resemble a uniform circular plate projecting from the bridge 995. Meanwhile, the front head 992 has a combined shape, consisting of a stem 993, having a substantially rectangular shape, and a bulb 991, having a generally circular shape and positioned above the stem 993. The bulb 991 may be wider than the stem 993 measured in a heel to toe direction, thereby resembling a keyhole, as seen in FIG. 24. The bridge 995 may be a circular protrusion that connects the front head 992 and the rear head 994. In some embodiments, the front head 992, rear head 994, and bridge 995 are integrally formed.

[0109] Referring to FIGS. 24-28, the membrane 942 includes a web 945 defining a receptacle configured to receive the keyhole weight 999. The web 945 is recessed relative to both the membrane front exterior surface 946 and membrane rear exterior surface 948. The inset between the web 945 and the membrane front exterior surface 946 forms a front cavity 996 that receives the front head 992. In many embodiments, the front head 992 is flush with the membrane front exterior surface 946. The inset between the web 945 and the membrane rear exterior surface 948 forms a rear cavity 997 that receives the rear head 994. In some embodiments, the rear head 994 is flush with the membrane rear exterior surface 948. The web 945 further defines an aperture 990 that receives the bridge 995. In some embodiments, the aperture 990 extends through membrane bottom exterior surface 962, allowing the keyhole weight 999 to be inserted from below by sliding it upward into position within the web 945.

[0110] The keyhole weight 999 can be secured within the web 945 through various attachment mechanisms. In some embodiments, as illustrated in FIGS. 24 and 26, the front head 992 and rear head 994 clamp against the web 945, creating an interference fit that holds the keyhole weight 999 in place. In other embodiments, an adhesive, such as an epoxy, is used to permanently affix the keyhole weight 999 to the web 945. The selected attachment mechanism ensures that the keyhole weight 999 remains securely positioned within the club head to achieve the desired mass distribution and performance characteristics.

[0111] The configuration of the keyhole weight 999 can achieve various desired club head mass properties. In some embodiments, either the front head 992 or the rear head 994 may be larger than the other, depending on the desired mass distribution of the club head. For example, in the illustrated embodiment, the front head 992 is significantly larger than the rear head 994, thereby providing a more forward CG position. Further, the stem 993 that extends from the bulb 991 down towards the membrane bottom exterior surface 962 lowers the CG position. In some embodiments, the front head 992 contacts the strike face interior surface and damps dominant impact vibrations, leading to enhanced sound and feel properties of the golf club head. The damping properties can be more perceptible when the keyhole weight 999 is made from a resin mixed with one or more powdered metals. In some embodiments, the rear head 994 may be larger than the front head 992 for a more rearward CG position, leading to more backspin, or the front head 992 and the rear head 994 can be substantially the same size for a more balanced CG position. The keyhole weight 999 can be made from different materials to modify the total mass of the pneumatic insert 940. Golf club manufacturers can leverage this to ensure that more fabricated golf club heads fit within narrow mass tolerances. Moreover, the shapes and sizes of the front head 992 and rear head 994 can be customized to achieve various CG locations and MOI values that are favorable for specific players. Further, the central position and large size relative to the membrane 942 render the keyhole weight 999 especially suitable for increasing MOI and stabilizing the CG location proximate the geometric center of the strike face.

[0112] In some embodiments, the pneumatic insert 1040 can comprise a one-sided keyhole opening configured to receive a keyhole weight 1099, as best illustrated in FIGS. 29 and 30. The keyhole weight 1099 comprises a weight body 1091 and a boss 1098 that protrudes from the weight body 1091. The membrane 1042 includes a web 1045 that creates a cavity configured to receive the keyhole weight 1099. The web 1045 comprises an intermediate surface 1090a that is recessed relative to the membrane front exterior surface 1046, and a base surface 1090b that is recessed relative to the intermediate surface 1090a. The inset between the membrane front exterior surface 1046 and the intermediate surface 1090a creates a preliminary recess 1096, whereas the inset between the intermediate surface 1090a and the base surface 1090b creates a smaller, secondary recess 1097. The weight body 1091 is configured to engage the preliminary recess 1096. The boss 1098 extends from the weight body 1091 deeper into the pneumatic insert 1040 and engages the secondary recess 1097. The web 1045 and the keyhole weight 1099 can comprise complementary geometries that allow the keyhole weight 1099 to be flush with the membrane front exterior surface 1046.

[0113] The configuration of the web 1045 and the keyhole weight 1099 can achieve various desired club head mass properties. In some embodiments, the web 1045 can form the cavity into the membrane rear exterior surface 1048 rather than the membrane front exterior surface 1046, if a more rearward CG position is preferred over a more forward CG position.EXAMPLESExample 1: CG Locations of Clubs Heads Comprising Weighted Pneumatic Inserts with Pin Weights

[0114] CG locations were measured across two different exemplary golf club heads comprising pin weight pneumatic inserts (as seen in FIG. 7), with the pin weights in either the toe or heel position, and a control golf club comprising a non-weighted pneumatic insert. The CG locations were determined using modeling software. This analysis placed a single 1.209 gram pin weight in a toeward position for Exemplary Club 1, and a single 1.209 gram pin weight in a heelward position for Exemplary Club 2. In both exemplary clubs, the receptacles of the pneumatic inserts lacking a weight remained empty. The differences in CG location between the control and exemplary club heads along each coordinate axis (signified as ΔCGx, ΔCGY, and ΔCGz) are shown in Table 1 below.TABLE 1CG Shift of Weighted Pneumatic Insertwith Pin Weight Exemplary Club HeadsPin WeightClub HeadMass (g)ΔCGx (in)ΔCGY (in)ΔCGZ (in)Exemplary Club 11.209−0.001−0.003−0.002Exemplary Club 21.2090.002−0.003−0.001

[0115] The exemplary club heads showed a shift in CG towards either the respective heel to toe direction (CGx), while further moving CG towards the sole (exemplified by ΔCGY) and rear (exemplified by ΔCGz). Specifically, the change between the toeward setting (Exemplary Club 1) and the heelward setting (Exemplary Club 2) accounted for 0.003 inches of heel-toe CG adjustability. Further, the pin weights were able to lower the CG position by 0.003 inches and shift the CG rearward by approximately 0.002 inches. Minor changes in CG can have drastic implications on shot trajectory. For example, heel-toe shifts in CG bias shots in a horizontal manner, lowered CG results in high launching, lower spinning trajectories, and rearward CG shifts account for improved forgiveness and increased spin.

[0116] Given the above results, the pin weight pneumatic insert effectively adjust CG post manufacturing. While the CG shifts along certain axes appear subtle, it should be appreciated that the CG movement can be increased. For instance, the pin weight pneumatic insert may be adapted to substantially fill a larger club head cavity, which provides more extreme weighting positions within the insert and cavity. Additionally, heavier materials may be used to fabricate the pin weight and / or the pin weight volume may be adjusted to increase CG adjustability post manufacturing.Example 2: Mass Properties of Clubs Heads Comprising Clamp Weight Pneumatic Inserts

[0117] A broader range of CG adjustment was explored by combining a clamp weight in a pneumatic insert. The CG location of the control golf club head (i.e., a non-weighted pneumatic insert) was compared against the CG location of an exemplary golf club head comprising a weighted pneumatic insert having a clamp weight (similar to that shown in FIG. 12). One clamp weight was disposed on the heel side of the membrane and had a mass of 7.538 grams. The differences in CG location between the control and exemplary club heads along each coordinate axis (signified as ΔCGX, ΔCGY, and ΔCGZ) are shown in Table 2 below.TABLE 2CG Differences Between the ExemplaryClub Head and Control Club HeadClampClub HeadWeight Mass (g)ΔCGx (in)ΔCGY (in)ΔCGZ (in)Exemplary7.5380.018−0.016−0.051

[0118] The weighted pneumatic insert with the clamp weight at the heel shifted the CG location along all three coordinate axes by a sufficient amount to impact ball trajectory. Most noticeably, the clamp weight shifted the CG rearward along the Z-axis (front towards the rear), by 0.051 inches. Rearward shifts in CG depth can increase spin, which is desirable for some golfers. Further, the clamp weight in the heel side resulted in a heelward shift in CGX compared to the control club head. Consequently, the exemplary club head can counteract dominant, “slice” spin, which often leads to uncontrollable misses for some golfers. The CG height also shifted downward by 0.016 inches between the exemplary and control club head, indicating that the exemplary club head can produce launch trajectories slightly higher than the control. While the CG shifts along certain axes appear subtle, the CG movement can be increased by positioning the clamp weight in different locations throughout the cavity or using heavier materials. Moreover, when the pneumatic insert substantially fills the cavity, the clamp weight may be placed in more discrete and / or extreme positions to further affect CG characteristics.Example 3: Mass Properties of Clubs Heads Comprising Weighted Pneumatic Inserts with Keyhole Weights

[0119] A centralized weight configuration was explored in the pneumatic insert, similar to FIGS. 24 and 26. The CG location of the control golf club head was compared against the CG location of an exemplary golf club head comprising a weighted pneumatic insert having a keyhole weight. The keyhole weight had a mass of 19.138 grams. The differences in CG location between the control and exemplary club heads along each coordinate axis (signified as ΔCGX, ΔCGY, and ΔCGZ) are shown in Table 3 below.TABLE 3CG Differences Between the ExemplaryClub Head and Control Club HeadKeyhole WeightΔCGxΔCGYΔCGZClub HeadMass (g)(in)(in)(in)Exemplary Club Head19.1380.008−0.024−0.009

[0120] The weighted pneumatic insert with the keyhole weight primarily affected CG height (CGY), which dropped by 0.024 inches (towards the sole) compared to the control club head. The central placement of the keyhole weight focused the CG shift along the Y-axis, while relatively stabilizing CG along the X-axis (heel to toe) and Z-axis (front to rear). As a result, the keyhole weight, in this configuration, would facilitate higher launching trajectories for the exemplary club head compared to the control. While the keyhole weight was 19.138 grams, the mass could be adjusted lower or higher for a variety of purposes. For one, keyhole weights may be composed of various materials having different densities to maintain head weighting across a set of clubs. Although the CGX and CGZ shifts appear minute, the keyhole weight may be placed other locations within the cavity to increase the effects on CGX and CGZ.Example 4: CG Shift of Club Head Comprising Weighted Pneumatic Inserts with Elongate Bar Weight

[0121] An exemplary golf club head comprising a weighted pneumatic insert having an elongate bar weight (as seen in FIG. 19) was compared to a control golf club comprising a non-weighted pneumatic insert for their CG locations. The CG location was determined using modeling software for the exemplary golf club head and the control golf club head. In this analysis, a 6.751 gram elongate bar weight was placed within the receptacle of the exemplary golf club head, while the control golf club head comprised a pneumatic insert having a similar shape and size to the elongate bar weight pneumatic insert, but without a receptacle. The differences in CG location between the control and exemplary club head along each coordinate axis (signified as ΔCGX, ΔCGY, and ΔCGZ) are shown in Table 4 below.TABLE 4CG Shift of Weighted Pneumatic Insert withElongate Bar Weight Exemplary Club HeadElongate BarΔCGxΔCGYΔCGZClub HeadWeight Mass (g)(in)(in)(in)Exemplary Club Head6.7510.003−0.015−0.006

[0122] The exemplary club head showed a shift in CG that was heelward, downward, and rearward. Specifically, CGx moved 0.003″ towards the heel, CGy shifted 0.015″ towards the sole, and CGz shifted 0.006″ rearward. Minor changes in CG can have drastic implications on shot trajectory. As expected, the low placement of the elongate bar weight impacted CGy the most. A lower CG placement results in high launching, lower spinning trajectories.

[0123] Given the above results, the weighted pneumatic insert having an elongate bar weight effectively adjusts CG post manufacturing. While the CG shifts along certain axes appear subtle, it should be appreciated that the CG movement can be increased. For instance, the weighted pneumatic insert with an elongate bar weight may be adapted to substantially fill a larger club head cavity, which provides more extreme weighting positions within the insert and cavity. The weighted pneumatic insert with an elongate bar weight may use heavier materials to fabricate the weight, thereby increasing CG adjustability post manufacturing. Further, the elongate bar weight can be asymmetrically cast to increase CGX (heel-toe) movement.Example 5: Vertical Launch and Spin Comparison Between Exemplary Club Head Comprising a Weighted Pneumatic Insert and a Control Club Head

[0124] In a performance test, fifteen experienced golfers each hit twenty shots with a control iron-type club head and an exemplary iron-type golf club head. Both golf club heads were capped hollow-body three irons, including pneumatic inserts. The exemplary club head was similar to the control club head, except that the exemplary club head had an elongate bar weight coupled to the pneumatic insert (as shown in FIGS. 21 and 22). Furthermore, the elongate bar weight was composed of a resin mixed with tungsten. The exemplary club head shifted the CGY towards the sole by 0.001 inch, relative to the control club head. Additionally, the weighted pneumatic insert increased the MOI of the entire golf club by 0.02%, relative to the control club head. Launch monitors recorded trajectory data (including vertical launch (deg), spin rate (rpm), and club head speed (mph)) for every shot struck by the golfers. The average recorded vertical launch, spin rate, and club head speed of the shots struck by the control and exemplary club heads is shown below, in Table 5.TABLE 5Trajectory Comparison Between Controland Exemplary Club HeadsSwing SpeedBall SpeedClub Head(mph)(mph)Launch (deg)Spin (rpm)Control100.5145.29.54,570Exemplary100.5145.49.84,630

[0125] The exemplary club head produced higher launching trajectories with slightly increased spin and ball speed (on average) compared to the control club head. The additional 0.2-mph ball speed increases carry distance by one to two yards, thereby helping players hit shots farther and potentially closer to their targets. Moreover, golfers maintained their swing speeds, at 100.5 mph on average, between the club heads, suggesting the club heads were similarly aerodynamic. Therefore, the slight performance differences between the control and exemplary club heads can be attributed to differences in mass properties, namely CG and MOI. The increase in launch angle of approximately 0.3 degree with the exemplary club head can be ascribed to a lower CG location relative to the control club head. Likewise, the increase in spin of 60 rpm corresponds to a slightly higher MOI for the exemplary club head over the control club head. These enhancements can lead to certain golfers (i.e., improving amateur golfers) hitting more greens in regulation and improving their consistency.

[0126] These results further exemplify that weighted pneumatic inserts are sufficient for closely tailoring CG and MOI to influence golf club head performance. While the weighted pneumatic insert in the exemplary club head lowered CG and increased MOI, other embodiments of weighted pneumatic inserts can be configured to shift CG and affect MOI in different respects. Thus, weighted pneumatic inserts can also influence trajectory in other ways, such as lowering launch angle and spin, which may be favorable for a different subset of golfers.CLAUSES

[0127] Clause 1. An iron-type golf club head, comprising: a body comprising; a front including a strike face and a strike face interior surface; a top rail including a top rail interior surface; a sole opposite the top rail and including a sole interior surface; a heel including a heel interior surface; a toe opposite the heel and including a toe interior surface; and a rear opposite the front and defining a rear wall extending at least partially between the sole and the top rail, wherein the rear wall includes a rear wall interior surface; wherein the strike face interior surface, the top rail interior surface, the sole interior surface, the heel interior surface, the toe interior surface, and the rear wall interior surface cooperate to form a body interior surface defining a cavity; a pneumatic insert disposed in the cavity, the pneumatic insert comprising: a membrane enclosing a hollow chamber filled with a pressurized gas at an insert pressure, comprising; a membrane front wall defining a membrane front exterior surface; a membrane rear wall spaced from the membrane front wall and defining a membrane rear exterior surface; and a membrane side wall extending between the membrane front wall and the membrane rear wall and defining a membrane perimeter exterior surface; and a first receptacle disposed inwardly of the membrane side wall including a first receptacle wall extending from the membrane front wall to the membrane rear wall, the first receptacle wall defining a first aperture fluidly communicating between the membrane front exterior surface and the membrane rear exterior surface; and a first weight disposed in the first receptacle.

[0128] Clause 2. The iron-type golf club head of clause 1, wherein the membrane further comprises: a second receptacle disposed inwardly of the membrane side wall including a second receptacle wall extending from the membrane front wall to the membrane rear wall independent of the first receptacle wall, the second receptacle wall defining a second aperture fluidly communicating between the membrane front exterior surface and the membrane rear exterior surface; and a second weight disposed in the second receptacle.

[0129] Clause 3. The iron-type golf club head of clause 1, wherein the first weight extends through the first aperture and comprises a front head, flush with the membrane front exterior surface, and a rear head, flush with the membrane rear exterior surface.

[0130] Clause 4. The iron-type golf club head of clause 1, wherein the first weight comprises a mass between 0.1 gram and 10 grams.

[0131] Clause 5. The iron-type golf club head of clause 1, wherein the first weight is composed of a resin mixed with powdered metal.

[0132] Clause 6. The iron-type golf club head of clause 1, wherein the first weight comprises a specific gravity greater than 4.0.

[0133] Clause 7. The iron-type golf club head of clause 1, wherein the membrane front exterior surface engages the strike face interior surface.

[0134] Clause 8. The iron-type golf club head of clause 1, wherein the membrane rear exterior surface engages the rear wall interior surface.

[0135] Clause 9. The iron-type golf club head of clause 1, wherein the membrane side wall comprises a membrane sole surface that engages the sole interior surface.

[0136] Clause 10. An iron-type golf club head, comprising: a body comprising; a front including a strike face and a strike face interior surface; a top rail including a top rail interior surface; a sole opposite the top rail and including a sole interior surface; a heel including a heel interior surface; a toe opposite the heel and including a toe interior surface; and a rear opposite the front and defining a rear wall extending at least partially between the sole and the top rail, wherein the rear wall includes a rear wall interior surface; and wherein the strike face interior surface, the top rail interior surface, the sole interior surface, the heel interior surface, the toe interior surface, and the rear wall interior surface cooperate to form a body interior surface defining a cavity; a pneumatic insert disposed in the cavity, the pneumatic insert comprising: a membrane enclosing a hollow chamber filled with a pressurized gas at an insert pressure, comprising; a membrane front wall defining a membrane front exterior surface; a membrane rear wall spaced from the membrane front wall and defining a membrane rear exterior surface; a membrane side wall extending between the membrane front wall and the membrane rear wall and defining a membrane perimeter exterior surface; a first web formed by a first web region of the membrane front wall directly coupled to a first web region of the membrane rear wall; and a first receptacle comprising a first aperture formed in the first web; and a first weight disposed in the first receptacle and engaging the first web.

[0137] Clause 11. The iron-type golf club head of clause 10, wherein the first web does not form any portion of the hollow chamber and is inset from the membrane front exterior surface and the membrane rear exterior surface.

[0138] Clause 12. The iron-type golf club head of clause 10, wherein the membrane further comprises: a second web formed by a second web region of the membrane front wall directly coupled to a second web region of the membrane rear wall; a second receptacle comprising a second aperture formed in the second web; and a second weight disposed in the second receptacle and engaging the second web.

[0139] Clause 13. The iron-type golf club head of clause 10, wherein the first weight extends through the first aperture and comprises a front head and a rear head.

[0140] Clause 14. The iron-type golf club head of clause 13, wherein the front head is recessed from the membrane front exterior surface.

[0141] Clause 15. The iron-type golf club head of clause 13, wherein the rear head is recessed from the membrane rear exterior surface.

[0142] Clause 16. The iron-type golf club head of clause 10, wherein the first weight comprises a mass between 0.1 gram and 10 grams.

[0143] Clause 17. The iron-type golf club head of clause 10, wherein the first weight comprises a specific gravity greater than 4.0.

[0144] Clause 18. The iron-type golf club head of clause 10, wherein the membrane front exterior surface engages the strike face interior surface.

[0145] Clause 19. The iron-type golf club head of clause 10, wherein the membrane rear exterior surface engages the rear wall interior surface.

[0146] Clause 20. The iron-type golf club head of clause 10, wherein the membrane side wall comprises a membrane sole surface that engages the sole interior surface.

[0147] Replacement of one or more claimed elements constitutes reconstruction and not repair. Additionally, benefits, other advantages, and solutions to problems have been described with regard to specific embodiments. The benefits, advantages, solutions to problems, and any element or elements that may cause any benefit, advantage, or solution to occur or become more pronounced, however, are not to be construed as critical, required, or essential features or elements of any or all of the claims, unless such benefits, advantages, solutions, or elements are stated in such claim.

[0148] Moreover, embodiments and limitations disclosed herein are not dedicated to the public under the doctrine of dedication if the embodiments and / or limitations: (1) are not expressly claimed in the claims; and (2) are or are potentially equivalents of express elements and / or limitations in the claims under the doctrine of equivalents.

Claims

1. An iron-type golf club head, comprising:a body comprising;a front including a strike face and a strike face interior surface;a top rail including a top rail interior surface;a sole opposite the top rail and including a sole interior surface;a heel including a heel interior surface;a toe opposite the heel and including a toe interior surface; anda rear opposite the front and defining a rear wall extending at least partially between the sole and the top rail, wherein the rear wall includes a rear wall interior surface;wherein the strike face interior surface, the top rail interior surface, the sole interior surface, the heel interior surface, the toe interior surface, and the rear wall interior surface cooperate to form a body interior surface defining a cavity;a pneumatic insert disposed in the cavity, the pneumatic insert comprising:a membrane enclosing a hollow chamber filled with a pressurized gas at an insert pressure, comprising;a membrane front wall defining a membrane front exterior surface;a membrane rear wall spaced from the membrane front wall and defining a membrane rear exterior surface; anda membrane side wall extending between the membrane front wall and the membrane rear wall and defining a membrane perimeter exterior surface; anda first receptacle disposed inwardly of the membrane side wall including a first receptacle wall extending from the membrane front wall to the membrane rear wall, the first receptacle wall defining a first aperture fluidly communicating between the membrane front exterior surface and the membrane rear exterior surface; anda first weight disposed in the first receptacle.

2. The iron-type golf club head of claim 1, wherein the membrane further comprises:a second receptacle disposed inwardly of the membrane side wall including a second receptacle wall extending from the membrane front wall to the membrane rear wall independent of the first receptacle wall, the second receptacle wall defining a second aperture fluidly communicating between the membrane front exterior surface and the membrane rear exterior surface; anda second weight disposed in the second receptacle.

3. The iron-type golf club head of claim 1, wherein the first weight extends through the first aperture and comprises a front head, flush with the membrane front exterior surface, and a rear head, flush with the membrane rear exterior surface.

4. The iron-type golf club head of claim 1, wherein the first weight comprises a mass between 0.1 gram and 10 grams.

5. The iron-type golf club head of claim 1, wherein the first weight is composed of a resin mixed with powdered metal.

6. The iron-type golf club head of claim 1, wherein the first weight comprises a specific gravity greater than 4.0.

7. The iron-type golf club head of claim 1, wherein the membrane front exterior surface engages the strike face interior surface.

8. The iron-type golf club head of claim 1, wherein the membrane rear exterior surface engages the rear wall interior surface.

9. The iron-type golf club head of claim 1, wherein the membrane side wall comprises a membrane sole surface that engages the sole interior surface.

10. An iron-type golf club head, comprising:a body comprising;a front including a strike face and a strike face interior surface;a top rail including a top rail interior surface;a sole opposite the top rail and including a sole interior surface;a heel including a heel interior surface;a toe opposite the heel and including a toe interior surface; anda rear opposite the front and defining a rear wall extending at least partially between the sole and the top rail, wherein the rear wall includes a rear wall interior surface; andwherein the strike face interior surface, the top rail interior surface, the sole interior surface, the heel interior surface, the toe interior surface, and the rear wall interior surface cooperate to form a body interior surface defining a cavity;a pneumatic insert disposed in the cavity, the pneumatic insert comprising:a membrane enclosing a hollow chamber filled with a pressurized gas at an insert pressure, comprising;a membrane front wall defining a membrane front exterior surface;a membrane rear wall spaced from the membrane front wall and defining a membrane rear exterior surface;a membrane side wall extending between the membrane front wall and the membrane rear wall and defining a membrane perimeter exterior surface;a first web formed by a first web region of the membrane front wall directly coupled to a first web region of the membrane rear wall; anda first receptacle comprising a first aperture formed in the first web; anda first weight disposed in the first receptacle and engaging the first web.

11. The iron-type golf club head of claim 10, wherein the first web does not form any portion of the hollow chamber and is inset from the membrane front exterior surface and the membrane rear exterior surface.

12. The iron-type golf club head of claim 10, wherein the membrane further comprises:a second web formed by a second web region of the membrane front wall directly coupled to a second web region of the membrane rear wall;a second receptacle comprising a second aperture formed in the second web; anda second weight disposed in the second receptacle and engaging the second web.

13. The iron-type golf club head of claim 10, wherein the first weight extends through the first aperture and comprises a front head and a rear head.

14. The iron-type golf club head of claim 13, wherein the front head is recessed from the membrane front exterior surface.

15. The iron-type golf club head of claim 13, wherein the rear head is recessed from the membrane rear exterior surface.

16. The iron-type golf club head of claim 10, wherein the first weight comprises a mass between 0.1 gram and 10 grams.

17. The iron-type golf club head of claim 10, wherein the first weight comprises a specific gravity greater than 4.0.

18. The iron-type golf club head of claim 10, wherein the membrane front exterior surface engages the strike face interior surface.

19. The iron-type golf club head of claim 10, wherein the membrane rear exterior surface engages the rear wall interior surface.

20. The iron-type golf club head of claim 10, wherein the membrane side wall comprises a membrane sole surface that engages the sole interior surface.

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