Golf Club Head

Abstract

To provide golf club heads having cast components, and related methods for manufacturing such golf club heads.SOLUTION: A cast cup can include a forward portion of a golf club head, including a hosel, a face portion, a crown forward portion, a sole forward portion, a heel forward portion and a toe forward portion. A rear ring can be formed separately from the cast cup and coupled to heel and toe portions of the cast cup to form a metallic club head body, such that the club head body defines a hollow interior region, a crown opening and a sole opening. The cast cup and rear ring can be cast from titanium alloys. Composite crown and sole inserts can then be coupled to the crown opening and sole opening. The face portion of the cast cup can desirably have a complex geometry. The rear surface of the face portion of the cast cup can be modified before the rear ring is attached.SELECTED DRAWING: None

Description

Technical Field

[0001] Cross - Reference to Related Applications This application is a continuation - in - part of U.S. Patent Application No. 16 / 059,801, filed on Aug. 9, 2018, and claims the benefit of U.S. Provisional Patent Application No. 62 / 543,778, filed on Aug. 10, 2017, both of which are hereby incorporated by reference in their entirety.

[0002] The present disclosure relates to golf club heads having cast components and related methods for manufacturing such golf club heads.

Background Art

[0003] Due to the ever - increasing popularity and competitiveness of golf, a significant amount of effort and resources are currently being expended to improve golf clubs. Most recent improvement activities relate to combinations of the use of newly refined materials in concert with state - of - the - art club head engineering. For example, the latest “wood - type” golf clubs (e.g., “driver”, “fairway wood”, “rescue”, and “utility or hybrid club”) with refined shafts and non - wooden club heads bear little resemblance to the “wood” drivers, low - loft long irons, and higher - numbered fairway woods that were used even a few years ago. These latest wood - type clubs are generally referred to as “metal woods” or simply “woods”.

[0004] Current capabilities for making metalwood club heads from strong and lightweight metals and other materials allow the club head to be made hollow. Also, by using high-strength and high fracture toughness materials, it is possible to thin the walls of the club head, resulting in a reduced total weight and allowing for an increase in club head size compared to previous club heads without the penalty in swing speed due to increased weight. Larger club heads tend to have a larger face plate area and can be made with a high club head inertia, whereby the club head has a higher "tolerance" than smaller club heads. Characteristics such as the size of the optimal impact position (also known as the "sweet spot") are determined by many variables including the shape, profile, size, and thickness of the face plate, as well as the position of the center of gravity (CG) of the club head.

[0005] Exemplary metalwood golf clubs typically include a shaft having a lower end to which the club head is attached. Most modern versions of these club heads are made of lightweight but strong metals such as titanium alloys, at least in part. The club head may include a body to which a face plate (used interchangeably herein with the terms "face", "face insert", "striking plate" or "strike plate") is later attached, or the body and face place may be cast together as a single structure so that there is no need to later attach the face plate to the body. The face plate defines the front face or striking face that actually contacts the golf ball.

[0006] If the total mass of a metalwood club head is regarded as the mass budget of the club head, at least a part of the mass budget must be dedicated to providing sufficient strength and structural support to the club head. This is called "structural" mass. The remaining mass within the budget is called "discretionary" or "performance" mass and can be distributed, for example, within the metalwood club head to address performance issues. Therefore, the ability to reduce the structural mass of a metalwood club head without compromising strength and structural support offers the possibility of increasing the discretionary mass and thereby improving club performance.

[0007] One opportunity to reduce the total mass of the club head is to reduce the mass of the face plate by reducing its thickness. However, considering that the face has very strict requirements for its physical and mechanical properties to absorb the initial impact of the ball, the opportunity to do this is somewhat limited. Club manufacturers are using titanium and titanium alloys in the manufacture of the face plate and the club head as a whole, taking into account light weight and high strength. Usually, for club heads with relatively complex three-dimensional structures considered, a casting process is used in their manufacture. Many such face plates are made by an investment casting method in which a suitable molten metal is poured into a preheated ceramic investment mold formed by the lost wax process. Investment casting is also used to prepare the face plate as an integral structure cast together with the rest of the club head body, or as a separately formed face plate usually attached to the front of the club head body by welding. Although widely used, the investment casting of such complex-shaped parts of reactive materials is characterized by relatively high costs and low yields. The low casting yield is due to several factors including surface or surface-related void-type defects, and / or insufficient filling of specific mold cavity areas, especially thin mold cavity areas, and related internal voids, shrinkage, etc.

[0008] To further compensate for investment casting defects in the faceplate, clubhead manufacturers often introduce curvature to the face of the club to help correct directional problems caused by shots away from the center of gravity. Thus, manufacturers may desire to form a face having both a convex curvature from heel to toe (referred to as a "bulge") and a convex curvature from crown to sole (referred to as a "roll") rather than a flat faceplate. Additionally, manufacturers can introduce a variable face thickness profile across the faceplate. Varying the thickness of the faceplate can increase the size of the clubhead COR region, commonly referred to as the sweet spot of the golf clubhead, which allows for a larger area of the faceplate to consistently provide high golf ball speeds and shot tolerance when hitting a golf ball with a golf clubhead. Also, varying the thickness of the faceplate can advantageously reduce the weight of the face area for repositioning to another area of the clubhead.

[0009] To compensate for investment casting defects in these more complex faceplate structures, manufacturers are looking at an alternative method of forming the faceplate that includes laser cutting the shape of the faceplate from a rolled titanium sheet, then forging to impart any desired bulge and roll, and then performing machining steps on a lathe to introduce any desired face thickness profile. The drawbacks of these steps include the need for three separate forming steps, the lathe machining process for forming the variable thickness profile being not only wasteful but also including the fact that the profile is limited to a circular area as a result of the circular motion of the lathe.

[0010] Thus, it would be highly desirable to have a face plate for a club head that has physical properties sufficient to allow for a reduction in thickness and provide more available discretionary weight in the club head. Also, it would be desirable if the face plate could exhibit any desired bulge and roll curvature in addition to any variable thickness profile having a circular, oval, asymmetric, or other shape of any shape. Also, it would be desirable to be able to use a simplified process for manufacturing such a face plate, whereby a face plate having the required thickness and physical strength properties is obtained, which process also requires a minimum number of processing steps and minimizes any waste generated in the process, while obtaining a face plate having any desired bulge and roll as well as a variable thickness profile. Also, it would be desirable if the club head body and face could be cast simultaneously from the same material as a single integral body rather than two parts that would have to be attached together later. Also, it would be desirable if the cast face plate did not require chemical etching to remove or reduce the thickness of the alpha case in order to provide sufficient durability to the face plate.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] Some golf club head bodies disclosed herein can be cast from 9-1-1 titanium, and the face plate is cast as an integral part of the body along with the crown, sole, skirt, and hosel. The 9-1-1 titanium material allows for less oxygen uptake from the mold in the face plate and other parts of the body, reducing the thickness of the alpha case, resulting in increased ductility and durability. This eliminates the need to reduce the thickness of the alpha case after casting using hydrofluoric acid or other dangerous chemical etching agents.

MEANS FOR SOLVING THE PROBLEMS

[0012] The casting method can include preheating the mold to a temperature lower than room temperature and / or coating the inner surface of the mold in order to further reduce the amount of oxygen that moves from the mold to 9-1-1 titanium during casting.

[0013] In some embodiments, a wood-type golf club head body includes a crown, sole, skirt, face plate, and hosel, the body defines a hollow interior region, the body is substantially entirely cast from 9-1-1 titanium, the body is cast as a single integral casting, and the face plate is formed integrally with the crown, sole, skirt, and hosel. The body may contain trace amounts of fluorine atoms as alloying impurities found in titanium alloys, but the fluorine content present in the body can be very low because the face is not etched with hydrofluoric acid after casting. In some embodiments, the face plate may be substantially free of fluorine atoms such as less than 1000 ppm, less than 500 ppm, less than 200 ppm, and / or less than 100 ppm. In some embodiments, the body can have an alpha case thickness of 0.150 mm or less, 0.100 mm or less, and / or 0.070 mm or less.

[0014] Some exemplary methods include preparing a mold for casting and then casting a golf club head body substantially entirely made of 9-1-1 titanium using the mold, the casting includes a crown, sole, skirt, face plate, and hosel, the casting defines a hollow interior region, the body is cast as a single integral casting, and the face plate is formed integrally with the crown, sole, skirt, and hosel during casting. Some of these methods do not include etching the face plate after casting. In some methods, preparing the mold includes preheating the mold so that the mold is at a temperature of 800 °C or less, 700 °C or less, 600 °C or less, and / or 500 °C or less when casting is performed.

[0015] Also disclosed are embodiments of a golf club head including a cast cup made of metal that forms a front portion of the club head, including a hosel, a face portion, a front portion of the crown, and a front portion of the sole. A metal rear ring is formed separately from the cast cup and coupled to the heel and toe portions of the cast cup to form a club head body such that the metal club head body defines a hollow interior region, a crown opening, and a sole opening. Next, a composite crown insert can be coupled to the crown opening. A sole insert made of a composite material, metal, or other material can be coupled to the sole opening. In some embodiments, there is no sole opening or sole insert. The cast cup and the rear ring can be cast from a titanium alloy and both can be welded to form the club head body. In some embodiments, the ring and the cup are made of different metal materials such as two different titanium alloys or a titanium alloy and steel. The cast cup can include a face portion having a complex shape to provide desired performance characteristics. The face portion can have a twisted front face and / or the rear face of the face can have a shape that provides an asymmetric variable thickness profile across the face. The rear face of the face portion of the cast cup can be machined and / or otherwise modified prior to attaching the rear ring to increase the space for accessing the entire rear face of the face with a tool.

[0016] Also disclosed is a method of forming a wax cup from a wax cup frame and a separately formed wax face using a wax welding method. Next, such a wax cup can be used to create a mold for casting a metal cup that forms a front portion of a golf club head. The two-part wax welding method can provide advantages in manufacturing, prototyping, and testing.

[0017] Also disclosed is a cast face plate including a titanium alloy having a novel shape.

[0018] The foregoing and other objects, features, and advantages of the disclosed technology will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0019]

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DETAILED DESCRIPTION OF THE INVENTION

[0020] Embodiments of a golf club head for a metal wood type golf club, including drivers, fairway woods, rescue clubs, utility clubs, hybrid clubs, etc., will be described below.

[0021] The features of the invention disclosed in this specification include all novel and non-obvious features disclosed herein, alone and in combination with any other feature. As used herein, the phrase "and / or" means "and", "or", and both "and" and "or". As used herein, the singular forms "a", "an", and "the" refer to one or more unless the context clearly indicates otherwise. As used herein, the term "includes" means "comprises".

[0022] Reference is also made to the accompanying drawings which form a part of this specification. The drawings illustrate specific embodiments, but other embodiments can be formed and structural changes can be made without departing from the intended scope of the disclosure. Directions and references (e.g., up, down, upper, lower, left, right, rear, front, heel direction, toe direction, etc.) may be used to facilitate consideration of the drawings, but are not intended to be limiting. For example, specific terms such as "up", "down", "upper", "lower", "horizontal", "vertical", "left", "right", etc. can be used. These terms are used, when applicable, to make the description somewhat clearer when dealing with relative relationships, particularly with respect to the illustrated embodiments. However, such terms do not mean absolute relationships, positions, and / or orientations. For example, with respect to an object, the "upper" surface can be made the "lower" surface by simply rotating the object. Nevertheless, the object remains the same object. Accordingly, the following detailed description is not to be construed in a limiting sense, and the scope of the required property rights is defined by the appended claims and their equivalents.

[0023] In particular, conditional language such as "can", "has been able to", "has been able to", "might", etc., generally conveys that a particular embodiment includes a particular feature, element, and / or step, unless otherwise specified or understood in another sense within the context in which it is used, while other embodiments do not. Thus, such conditional language generally does not intend to convey that a feature, element, and / or step is required in any way for one or more particular embodiments, or that one or more particular embodiments necessarily include logic for determining whether these features, elements, and / or steps are included in, or should be performed in, any particular embodiment, regardless of the presence or absence of user input or prompt.

[0024] It should be emphasized that the embodiments described herein are merely examples of possible implementations and are only for the purpose of clearly understanding the principles of the present disclosure. Any process description or block in the flowchart should be understood to represent a module, segment, or portion of code that includes one or more executable instructions for implementing a particular logical function or step in the process, and alternative implementations that deviate from the order shown or discussed, including substantially simultaneous or reverse orders, may be included depending on the relevant functions, as reasonably understood by those skilled in the art of the present disclosure, where no function is included or performed at all. Many variations and modifications can be made to the above-described (one or more) embodiments without substantially departing from the spirit and principles of the present disclosure. Furthermore, the scope of the present disclosure is intended to cover all combinations and sub-combinations of all elements, features, and aspects described above. All such modifications and variations are intended to be included within the scope of the present disclosure, and all possible claims for individual aspects or combinations of elements or steps are to be supported by the present disclosure.

[0025] For reference, within the present disclosure, references to a "driver type golf club head" mean any metalwood type golf club head that is intended to be used primarily with a tee. Generally, a driver type golf club head has a loft of 15 degrees or less, more typically 12 degrees or less. References to a "fairway wood type golf club head" mean any wood type golf club head that is intended to be used to hit a ball from the ground while also being useable to hit a ball from a tee. Generally, a fairway wood type golf club head has a loft of 15 degrees or more, more typically 16 degrees or more. Generally, a fairway wood type golf club head has a length from leading edge to trailing edge of 73 to 97 mm. Various definitions distinguish between a fairway wood type golf club head and a hybrid type golf club head, with the hybrid type golf club head tending to resemble a fairway wood type golf club head but having a shorter length from leading edge to trailing edge. Generally, a hybrid type golf club head has a length from leading edge to trailing edge of 38 to 73 mm. A hybrid type golf club head can also be distinguished from a fairway wood type golf club head by weight, lie angle, volume, and / or shaft length. The driver type golf club head of the present disclosure may be 15 degrees or less in various embodiments, or 10.5 degrees or less in various embodiments. In various embodiments, the fairway wood type golf club head of the present disclosure can be 13 to 26 degrees.

[0026] As shown in FIGS. 1-6, a golf club head of the wood type (e.g., driver or fairway wood), such as golf club head 2, can include a hollow body 10. The body 10 can define an internal cavity while including a crown 12, a sole 14, a skirt 16, and a face plate 18 (also referred to as a face or face portion) that defines a striking face 22. The face plate 18 can be formed separately from the body and attached to an opening in the front portion of the body, or can be integrally formed as an integral part of the body 10. The body 10 can include a hosel 20 that defines a hosel bore 24 adapted to receive a golf club shaft (see FIG. 6). The body 10 further includes a heel portion 26, a toe portion 28, a front portion 30, and a rear portion 32.

[0027] FIGS. 4-6 show an ideal impact position 23 / origin 60, an origin x-axis 70, an origin y-axis 75, and an origin z-axis 65, the center of gravity 50 of the club head, a CGx-axis 90, a CGy-axis 95, and a CGz-axis 85. As shown, these axes are horizontal or vertical and the club head is in a normal address position. The origin axes pass through origin 60 and the CG axes pass through CG 50.

[0028] The body can further include openings in the crown and / or sole that are covered or lined with inserts formed of a lighter material such as a composite material. For example, the crown of the body can include a composite crown insert that covers most of the area of the crown and has a lower density than the metal from which the body is made, thereby saving weight of the crown. Similarly, the sole can include one or more openings within the body that are covered by a sole insert. The sole insert can be made of a composite material, a metal material, or other materials. In embodiments where the body includes an opening in the crown or sole, such an opening can provide access to the internal cavity of the club head during manufacturing, particularly when the face plate is formed as an integral part of the body during casting (and there is no face opening in the body to provide access during manufacturing). The club heads disclosed herein in connection with FIGS. 20-36 provide examples of openings in the crown and sole that are covered or lined with inserts formed of a lighter weight material (e.g., a composite material). Detailed information regarding the openings in the body and related inserts can be found in U.S. Patent Publication No. 2018 / 0185719, published Jul. 5, 2018, and U.S. Patent Application No. 62 / 515,401, filed Jun. 5, 2017, both of which are hereby incorporated by reference in their entirety.

[0029] In some embodiments, the club head can include adjustable weights, such as one or more weights movable along a weight track formed in the sole and / or perimeter of the club head. Other exemplary weights can be adjusted by rotating the weight within a threaded weight port. Various ribs, struts, mass pads, and other structures can be included within the body for purposes of providing reinforcement, adjusting mass distribution and MOI characteristics, adjusting acoustic characteristics, and / or for other reasons.

[0030] Assuming that any opening is substantially planar and sealed, a wood type club head, such as club head 2, has a volume displacement equal to the volume of the club head in generally cubic centimeters (cm 3) has a volume measured by (see the United States Golf Association's "Procedure for Measuring the Club Head Size of Wood Clubs", Revision 1.0, November 21, 2003). In the case of a driver, the golf club head has a volume of about 300 cm 3 to about 500 cm 3 such as about 250 cm 3 to about 600 cm 3 and can have a total mass of about 145 g to about 260 g. In the case of a fairway wood, the golf club head can have a volume of about 120 cm 3 to about 300 cm 3 and can have a total mass of about 115 g to about 260 g. In the case of a utility club or hybrid club, the golf club head can have a volume of about 80 cm 3 to about 140 cm 3 and can have a total mass of about 105 g to about 280 g.

[0031] The sole 14 is defined as the lower part of the club head 2 that extends upward from the lowest point of the club head when the club head is ideally positioned, i.e., at an appropriate address position relative to the golf ball on the horizontal plane. In some implementations, the sole 14 extends from about 50% to 60% of the distance from the lowest point of the club head to the crown 12 and can be, in some cases, about 15 mm for a driver and about 10 mm to 12 mm for a fairway wood.

[0032] Materials that can be used to construct the body 10 including the face plate 18 may include composite materials (e.g., carbon fiber reinforced polymer materials), titanium or titanium alloys, steel or steel alloys, magnesium alloys, copper alloys, nickel alloys, and / or any other metal or metal alloy suitable for golf club head construction. Other materials such as paints, polymer materials, ceramic materials, etc. can also be included within the body. In some embodiments, the body including the face plate is made of titanium or titanium alloys (including but not limited to 9-1-1 titanium, 6-4 titanium, 3-2.5, 6-4, SP700, 15-3-3-3, 10-2-3, or other alpha / near-alpha, alpha-beta, beta / near-beta titanium alloys), or aluminum and aluminum alloys (including but not limited to 3000 series alloys, 5000 series alloys, 6000 series alloys such as 6061-T6, 7000 series alloys such as 7075), Ti grade 9 (Ti-3Al-2.5V) having a chemical composition of 3.5 to 2.5% or less of Al, 3.0 to 2.0% or less of V, 0.02% or less of N, 0.013% or less of H, 0.12 or less of Fe, etc., and can be made of metal materials.

[0033] Investment casting aspects Injection molding is used to form a sacrificial "initial" pattern of the desired casting (e.g., made of casting "wax"). Suitable injection dies can be made of aluminum, other suitable metals or metal alloys, or other materials, for example, by a computer-controlled machining process using a casting master. CNC (Computer Numerical Control) machining can be used to form the complexity of the mold cavities within the die. The cavity dimensions are established to correct for the linear and volumetric shrinkage of the casting wax that occurs during the casting of the initial pattern and to correct for similar shrinkage phenomena expected to occur during the actual metal casting that is later performed using the investment casting "shell" formed from the initial pattern.

[0034] Typically, a group of initial patterns are assembled together and attached to a central wax sprue to form a casting "cluster". Each initial pattern within the cluster forms its respective mold cavity within a casting shell that is later formed around the cluster. The central wax sprue defines the location and configuration of runner channels and gates for routing the molten metal introduced into the sprue to the mold cavities within the casting shell. The runner channels can include one or more filters (e.g., made of ceramic) to facilitate a smooth laminar flow of molten metal within and into the casting shell and to prevent the intrusion of dross into the shell cavities that can be trapped within the mold.

[0035] The casting shell is constructed by immersing the casting cluster in a liquid ceramic slurry and then in a bed of refractory particles. This immersion sequence can be repeated as necessary to build up a sufficient wall thickness of ceramic material around the casting cluster, thereby forming an investment casting shell. An exemplary immersion sequence includes six immersions of the casting cluster in the liquid ceramic slurry and five immersions in the bed of refractory particles, resulting in an investment casting shell that includes alternating layers of ceramic slurry and refractory material. The first two layers of refractory material desirably include fine (300 mesh) zirconium oxide particles, and the third through fifth layers of refractory material can include coarser (200 mesh to 35 mesh) aluminum oxide particles. Each layer is dried under controlled temperature (25 ± 5 °C) and relative humidity (50 ± 5%) before applying the next layer.

[0036] The investment casting shell is placed in a sealed steam autoclave where the pressure rapidly increases to 7 - 10 kg / cm 2 Under such conditions, the wax within the shell is melted using the injected steam. The shell is then fired in an oven that is heated to 1000 - 1300 °C to remove the residual wax and increase the strength of the shell. At this point, the shell is ready to be used in investment casting.

[0037] After designing the club head and creating the initial pattern, the manufacturing operation transfers to a metal casting machine. To create an investment casting shell, the metal casting machine first constructs a cluster that includes multiple initial patterns for individual club heads. The construction of the cluster also includes the construction of a metal supply system (gates and runners for later supplying molten metal). After completing these operations, the casting machine prepares to manufacture the casting shell.

[0038] An important aspect of constructing the cluster is determining where to place the gates. Each individual club head mold cavity typically has one main gate through which molten metal flows into the mold cavity. Additional auxiliary ("assistant") gates can be connected to the main gate by flow channels. During investment casting using such a shell, the molten metal flows into each mold cavity through its respective main gate, flow channel, and auxiliary gate. In such a flow, the mold for forming the initial pattern of the club head needs to define the main gate and any assistant gates as well. After forming the initial pattern of the wax for the club head, the initial pattern is removed from the mold, and the location of the flow channel is defined by "adhering" (using the same wax) wax pieces between the gates. Referring to FIG. 12, an initial pattern 150 for a metalwood club head is shown. A main gate 152 and three assistant gates 154 are shown. The flow channel 156 interconnects the assistant gate 154 and the main gate 152.

[0039] Next, a plurality of initial patterns of each club head are incorporated into clusters, which includes attaching individual main gates to "ligaments". The ligaments include the sprue and runners of the cluster. Usually, a "receptor" made of graphite or the like is placed at the center of the cluster, and the receptor is later used to receive the molten metal and direct the metal into the runners. The receptor preferably has a "funnel" configuration to assist the inflow of the molten metal. Additional braces (e.g., made of graphite) can be added to strengthen the cluster structure.

[0040] Normally, the entire wax cluster is large enough (especially when the furnace chamber used for shell formation is large), and after first "adhering" fragments of wax to the individual branches of the cluster, the individual branches can be separately ceramic coated before the branches are assembled together into the cluster. Next, after assembling the branches together, the cluster is transferred to the shell casting chamber.

[0041] Two exemplary clusters are shown in FIGS. 13 and 14 respectively. In FIG. 13, the depicted cluster 160 includes a graphite receptor 162, graphite cross spokes 164, runners 166, and mold cavities 168. Each mold cavity 168 is for a respective club head. The molten metal in the crucible 170 is poured into the cluster 160 using the pouring cup 172, and the pouring cup directs the molten metal to the receptor 162, the branches 166, and then the mold cavities 168. In FIG. 14, the depicted cluster 180 includes a receptor 182 coupled to a shell runner 184. In this configuration, there are two types of mold cavities: "straight feed" cavities 186 and "side feed" cavities 188. The molten metal in the crucible 170 is poured into the cluster 180 using the pouring cup 172, and the pouring cup directs the molten metal to the receptor 182, the shell runner 184, and then the mold cavities 186, 188.

[0042] Next, the strengthened wax clusters are coated with multiple layers of slurry and ceramic powder, with drying being carried out between the coatings. After all the layers are formed, the resulting investment casting shell is autoclaved to melt the internal wax (the ceramic and graphite parts do not melt). After removing the wax from the shell, the shell is sintered (fired), significantly improving its mechanical strength. If the shell is used in a relatively small metal casting furnace (for example, when it can hold only a single-branch cluster), the shell can be used for investment casting. If the shell is used in a relatively large metal casting furnace, the shell can be combined with other shell branches to form a large multi-branched cluster.

[0043] Modern investment casting of metal alloys is usually carried out while rotating the casting shell in a centrifugal manner, utilizing the force generated by the ω 2 r acceleration of the shell under such movement, where ω is the angular velocity of the shell and r is the radius of angular motion. This rotation is carried out using a turntable within the casting chamber under near-atmospheric pressure. The force generated by the ω 2 r acceleration of the shell promotes the flow of the molten metal into the mold cavity without leaving voids. The investment casting shell (including the constituent clusters and runners) is usually assembled outside the casting chamber and heated to a preset temperature before being placed as an integral unit on the turntable within the chamber. After attaching the shell to the turntable, the casting chamber is sealed and evacuated to a preset near-atmospheric pressure ("vacuum") level. When the chamber is evacuated, the molten alloy for casting is prepared and the turntable begins to rotate. When the molten metal is ready to be poured into the shell, the casting chamber is at the appropriate vacuum level, the casting shell is at the appropriate temperature, and the turntable is rotating at the desired angular velocity. Thus, the molten metal is poured into the receptacle of the casting shell, flows throughout the shell, and fills the mold cavity of the shell.

[0044] When the molten metal flows into the shell cavity and comes into contact with the cavity surface, the high-temperature environment (from both the molten metal and the preheated shell) promotes the diffusion of elements such as oxygen in the shell material. Titanium casting is always carried out under near-atmospheric pressure (vacuum), and although oxygen is not available in the ambient environment, oxygen can still be found within the shell (since the shell is composed of multiple layers of "oxide"). Introducing oxygen into the molten titanium forms an alpha case, an oxygen-rich layer, on the surface of the titanium object being cast. Usually, the thickness of the alpha case is about 1 to 4% of the thickness of the object.

[0045] Since the alpha case is "enriched" with oxygen, it is brittle (although oxygen is one of the most effective elements for increasing the strength of titanium alloys, increasing strength significantly reduces ductility), and it may easily crack under load. To reduce the tendency to form an alpha case, it is necessary to lower the oxygen diffusion rate, and to lower the diffusion rate, it is necessary to lower the temperature. However, it is impossible to lower the temperature of the molten titanium. Therefore, lowering the temperature of the preheated shell is one way to lower the oxygen diffusion rate and reduce the formation of the alpha case.

[0046] Normally, before moving to the casting furnace, the casting shell is heated (referred to as preheating) to assist the flow of the molten titanium. The higher the preheating temperature of the shell, the easier the flow of the titanium. This is essential for thin-wall titanium casting, and the preheating temperature can reach 1100 - 1200°C. On the other hand, such high temperatures tend to produce a thick alpha case layer (towards the upper limit of the 1 - 4% wall thickness range). Therefore, when the formation of the alpha case is a concern, the preheating temperature of the casting shell can be lowered. Typically, for non-flowing critical titanium castings where the formation of the alpha case is not desirable, the preheating temperature of the casting shell is less than 1000°C, preferably less than 900°C.

[0047] Cluster casting method As can be seen with reference to FIG. 15, the method of manufacturing a golf club head includes preparing a cluster as disclosed elsewhere in this disclosure, as shown with reference to step 361. In various embodiments, the step of preparing the cluster may include a preheating step as disclosed elsewhere in this specification. One aspect of this disclosure is that the preheating of the cluster may be lower than that required by conventional investment casting techniques. For example, in conventional investment casting techniques, the preheating is about 1000° C. to 1400° C., and in the centrifugal casting of this disclosure, the preheating temperature may be less than 1000° C. in some embodiments, less than 800° C. in some embodiments, or about 500° C. or less in some embodiments. In some embodiments, preheating is not required and casting can occur at room temperature with the shell. Once the cluster is prepared, it can be angularly accelerated according to step 362. The metal may be heated to a molten state simultaneously with the preparation of the cluster and / or the acceleration of the cluster, or it may be an intermediate step. However, according to step 363, the metal can be heated to a molten state. According to step 364, the molten metal is introduced into the cluster. As indicated by the dashed line from step 362 to step 364, the cluster can be angularly accelerated before, after, or simultaneously with the introduction of the molten metal into the cluster. According to step 365, the molten metal is cooled. The cluster casting is removed from the cluster shell at step 366, and post-treatment occurs after step 367.

[0048] In some embodiments, step 363 includes heating the metal to a molten state. In various embodiments, the heating temperature may be higher or lower depending on the application. In some embodiments, step 362 includes angularly accelerating the cluster to an angular velocity, for example, up to about 360 revolutions per minute. In various embodiments, the angular velocity can be in the range of 250 to 450 revolutions per minute. In various embodiments, a low angular velocity of about 150 rpm and a high angular velocity of about 600 rpm may be suitable.

[0049] Since the casting temperature is low, the step of cooling the molten metal within the mold cluster involves a reduction in waiting time compared to conventional investment casting methods. As a result, the yield is improved and the cycle time is enhanced. With various conventional investment casting methods that rely on gravity, it was only possible to cast a maximum of 6 - 8 parts. Using centrifugal casting, since more than 18 - 25 parts can be cast in one cycle, the production capacity of one casting cycle is increased. Furthermore, the yield per gram of injection also increases. With conventional investment casting methods, a certain mass of metal is used to cast a certain number of golf club heads. With the spin casting technology of the present disclosure, more golf club heads can be manufactured using the same mass of metal. The improvements and honing of the technology in the present disclosure can further reduce this mass of metal per head. Depending on the specific methodology, the cycle time may also be reduced. Additionally, the methods described herein lead to a reduction in the tool and capital costs required for the same production demand. Thus, the methods described herein reduce costs and improve production quality.

[0050] Furthermore, casting by the methods described herein leads to material savings and achieves a greater throughput because, as the acceleration increases and thereby force is applied to the casting, the material can more easily flow into more heads. Finally, alloys that are normally manufactured using other methods can be more easily cast into similar shapes.

[0051] Gating and cluster configuration To configure the gates and the (one or more) clusters, multiple factors need to be considered. These factors to be considered include, but are not necessarily limited to, (a) dimensional limitations of the casting chamber of the metal casting furnace, (b) handling requirements, particularly during the slurry dipping step for forming the investment casting shell, (c) achieving an optimal flow pattern of the molten metal within the investment casting shell, (d) providing at least a minimum strength to the (one or more) clusters of the investment casting shell to withstand the rotational movement during metal casting, (e) achieving a balance of minimizing waste of the metal (e.g., by providing a small cross-section to the runner) versus achieving a minimum resistance to the flow of the molten metal into the mold cavity (by providing a sufficiently large cross-section to the runner), and (f) achieving the mechanical balance of the clusters around the central axis of the casting shell. Item (e) can be important because after casting, the metal remaining in the runner may not form the product and instead may be "contaminated" (a portion of which is usually recycled). These structural elements are combined with metal casting parameters such as the preheat temperature and time of the shell, the vacuum level within the metal casting chamber, and the angular velocity of the turntable to produce the actual casting results. As the walls of the club head are made thinner and thinner, careful selection and balance of these parameters are essential to obtain sufficient investment casting results.

[0052] The details of investment casting performed with a metal casting machine tend to be unique. However, in past experiments with various titanium casting machines, some consistencies and some general trends have emerged. For example, a specific club head (volume 460 cm 3 , crown thickness 0.6 mm, and sole thickness 0.8 mm) was manufactured on each of six titanium casting machines (each with a metal casting furnace capacity of 10 kg to 80 kg), and the data tabulated in FIGS. 16 and 17 was created. The parameters listed in FIGS. 16 and 17 include the following.

[0053] "Maximum R" is the maximum radius of the cluster, "Minimum R" is the minimum radius of the cluster, "Wetted perimeter length" is the total perimeter length of the runner, "R (flow radius)" is the cross-sectional area of the runner / wetted perimeter length, "Sharp turn" is a turn of 90 degrees or more in the runner system, "Process loss rate" is the ratio of process loss to the injected material, "Maximum speed" is the speed at the maximum radius, "Minimum speed" is the speed at the minimum radius, "Maximum acceleration" is the acceleration at the maximum radius, "Minimum acceleration" is the acceleration at the minimum radius, "Maximum force" is the force at the maximum radius (note that this is an approximation of the magnitude of the force applied to the molten metal at the gate. Depending on each specific cluster design, the true force is almost always lower than the calculated value, and more complex clusters show a greater reduction in force.), "Minimum force" is the force at the minimum radius (note that this is an approximation of the magnitude of the force applied to the molten metal at the gate. Depending on each specific cluster design, the true force is almost always lower than the calculated value, and more complex clusters show a greater reduction in force.), "Maximum pressure" is the pressure of the molten metal in the runner at the maximum radius (= maximum force / runner cross-sectional area), "Minimum pressure" is the pressure of the molten metal in the runner at the minimum radius (= minimum force / runner cross-sectional area), "Maximum kinetic energy" is the kinetic energy of the molten metal at the maximum radius, "Density" is the density of the molten metal (titanium alloy) at the melting point of 1650 °C, "Viscosity" is the viscosity of molten titanium at 1650 °C, "Maximum Re number" is the Reynolds number of the pipe flow at the maximum radius, "Minimum Re number" is consistently defined as the maximum Re number, but is defined at the minimum radius.

[0054] Minimum force requirements Figures 16 and 17 provide a table of data showing that in order to achieve good casting yields, it is necessary to apply at least a minimum force (and thus at least a minimum pressure) to the molten metal entering the casting shell of each cluster. The force applied to the molten metal is partially generated by the mass of the actual molten metal entering the mold cavity within the cluster and the centrifugal force generated by the rotating turntable of the casting furnace. Since a smaller force can generally reduce the amount of molten metal required per club head for casting, it is desirable to reduce the minimum force. However, other factors tend to indicate an increase in this force, and these factors include thinner wall sections of the item being cast, more complex clusters (and thus more complex flow patterns of the molten metal), a decrease in the shell preheat temperature (resulting in a greater loss of thermal energy from the molten metal as it flows into the investment casting shell), and substandard shell quality such as a rough mold cavity wall. The data in Figures 16 and 17 show that the minimum force required to cast a titanium alloy club head with at least a portion of the wall having a thickness of 0.6 mm is approximately 160 Nt. The casting machine 1 achieved this minimum force.

[0055] From the minimum force requirement, a lower threshold for the amount of molten metal required for injection into the shell can be derived. Excluding inevitable pour losses, the best metal usage (as achieved with casting machine 1) was 386 g (0.386 kg) for club heads (including gates and some runners) each having a mass of approximately 200 g. This corresponds to a material utilization rate of 200 / 386 = 52 percent. The accelerations (maximum) applied to the investment casting shells by casting machines 2 - 6 were all greater than that applied by casting machine 1, but more molten metal was required for each of casting machines 2 - 6 to obtain a casting yield equivalent to that achieved by casting machine 1.

[0056] Some process losses (such as spattering, cooling metal adhering to the side walls of the crucible, and interruption of the supply of liquid titanium alloy, recovery of cleaning losses, etc.) are inevitable. Process losses impose an upper limit on the efficiency achievable with smaller casting furnaces, i.e., the proportion of process losses increases rapidly as the size of the furnace decreases, as shown in Figure 18.

[0057] On the other hand, smaller casting furnaces advantageously have simpler operation and maintenance requirements. Other advantages of small furnaces are as follows: (a) They tend to process small and simple clusters of mold cavities. (b) Small clusters tend to have separate runners for each mold cavity, which provides a better interfacial gate ratio for the flow of molten metal into the mold cavity. (c) The furnace can be preheated more easily and quickly before casting. (d) The furnace potentially provides a higher achievable shell preheating temperature. And (e) small clusters tend to have shorter runners, which results in a lower Reynolds number and thus a lower likelihood of destructive turbulence. Large casting furnaces tend not to have these advantages, while small casting furnaces tend to have more inevitable process losses of molten metal per mold cavity than large furnaces.

[0058] Considering the above, a cost-effective casting system (furnace, cluster, yield, net material cost) would seem to include medium-scale systems as long as appropriate cluster design and gate design considerations are incorporated into the configuration of the investment casting shells used in such furnaces. This can be seen from comparing casting machines 1, 4, and 5. The overall material usage (without considering process losses) by these three casting machines is very close (664 - 667 g / cavity). The material usage by casting machine 1 (considering process losses) is 386 g, while the material usage by casting machines 4 and 5 is 510 g. Therefore, although casting machines 4 and 5 can still be improved, casting machine 1 seems to have reached its limit in this regard.

[0059] Flow field considerations At least, the minimum threshold force applied to the molten metal entering the investment casting shell can typically be achieved by either changing the mass of the molten metal entering the shell or increasing the velocity, typically by decreasing one and increasing the other. There are practical limits to the extent to which the mass of the "pouring material" (molten metal) can be reduced. As the mass of the pouring material decreases, proportionally more acceleration is required to generate sufficient force to effectively move the molten metal into the investment casting shell. However, increasing the acceleration increases the likelihood of generating turbulent flow of the molten metal entering the shell. Turbulent flow is undesirable as it disrupts the flow pattern of the molten metal. If the flow pattern is disrupted, additional force may be required to "push" the metal through the main gate into the mold cavity.

[0060] The Reynolds number can be easily modified by changing the shape and / or dimensions of the (one or more) runners. For example, changing R (flow radius) directly affects the Reynolds number. The smaller R (flow radius) is, the smaller the minimum force is (the two are approximately correlated). Therefore, an advantageous consideration is to first reduce the Reynolds number to maintain a stable flow field of the molten metal and then adjust the amount of the pouring material to meet the minimum force requirement.

[0061] Other factors One contributing factor is preheating the investment casting shell before introducing the molten metal. Since the shell preheat temperature of casting machine 1 was the highest, casting machine 1 achieved a 94% yield with the lowest Reynolds number, the smallest amount of poured material (and thus the least force). Another factor is the complexity of the (one or more) clusters. Evaluating complex clusters is very difficult, and the high Reynolds numbers typically exhibited by such clusters are not the only variable that can be controlled to reduce the disruptive turbulence of the molten metal within such clusters. For example, the number of "sharp" turns (turns of 90 degrees or more) in the runner and mold cavity of the cluster is also a factor. With respect to FIGS. 16 and 17, the investment casting shell used by casting machine 1 has one sharp turn (and another less sharp turn), while the shell used by casting machine 6 has three sharp turns. Casting machine 6 may need to rotate the shell at a higher angular velocity just to overcome the flow resistance caused by these sharp turns. However, this does not reduce the turbulent flow pattern caused by the sharp turns. Therefore, an investment casting shell that includes simpler (one or more) clusters (with fewer sharp turns to allow a more "natural" flow path for the molten metal) is desirable.

[0062] Another factor is the runner-gate alignment. The interfacial gate ratio for casting machine 1 is closest to 100% (indicating optimal gating) compared to substantially inferior data from other casting machines. The "worst" is casting machine 3, whose investment casting shell had a Reynolds number roughly the same as that of casting machine 1, but casting machine 3 achieved only a 78% yield due to a low interfacial gate ratio (about 23%). The low interfacial gate ratio exhibited by the shell of casting machine 3 made it difficult to determine whether the cause of the low yield of casting machine 3 was insufficient injection material to fill the gate or the occurrence of "two-phase flow liquid and pores". In any case, the overall cross-sectional areas of the runner and the gate can be kept approximately equal (and constant) to each other as much as possible to achieve a constant flow rate of liquid metal throughout the shell at any point during injection. In thin-walled titanium alloy castings, this principle applies particularly to the interface between the runner and the main gate, and the interfacial gate ratio must be 1 (1.0) or more.

[0063] Yet another factor is the cross-sectional shape of the runner. Comparing casting machines 4 and 5, and casting machines 2 and 5, the triangular cross-section runner appeared to generate a lower Reynolds number than circular or rectangular runners. Using a triangular cross-section runner can cause interfacial gate ratio problems (because the metal flows from such a runner into a straight or circular cross-section gate), but the significant reduction in Reynolds number achieved using a triangular cross-section runner is worth investigating as the difference in injection materials used in casting machines 2 and 5 (showing 39 kg vs 32 kg).

[0064] A flowchart for constructing a cluster of investment casting shells is shown in FIG. 19. In the first step 301, overall considerations of the intended cluster are made, such as dimensions, handling, balance, etc. Next, the complexity of the cluster is reduced (step 302) by minimizing sharp turns and unnecessary (and indeed frequent) changes in the runner cross-section. The interface gate ratio is maintained as close to 1 as possible (step 303). Also, the Reynolds number is minimized as much as practicable (step 304). The angular velocity (RPM) of the turntable is finely adjusted and the preheat temperature of the shell is raised to obtain the highest possible product yield (step 305). Usually, the iteration (306) of steps 304 and 305 is necessary to achieve a satisfactory yield. In step 308, after a satisfactory yield has been achieved (307), the mass of the injected material (molten metal) is gradually decreased to reduce the force required to promote the flow of molten metal throughout the cluster without reducing the product yield and while maintaining other casting parameters.

[0065] Detailed information regarding investment casting methods and apparatus for casting thin-walled club heads using titanium alloys and other materials can be found in U.S. Patent No. 7,513,296, issued April 7, 2009, and U.S. Patent Application Publication No. 2016 / 0175666, published June 23, 2016, both of which are hereby incorporated by reference in their entirety. These incorporated references disclose methods and systems for casting a club head body that does not include a face plate (the face plate is later attached to the body), but the same or similar methods and systems having the same or similar benefits and advantages can be used to cast the club head body disclosed herein, which is a face of an integrally cast portion of the body where the face is not separately formed and is later attached to the body.

[0066] Detailed information regarding the coating of a mold for casting a titanium alloy and a method for manufacturing a mold having a face coat of calcium oxide for use in casting a titanium alloy can be found in U.S. Patent No. 5,766,329, issued June 16, 1998, which is hereby incorporated by reference in its entirety.

[0067] Club head including cast titanium alloy body / face Compared to the face of a titanium golf club formed for machining or forging of a sheet, a cast face has the advantages of low cost and complete freedom in design. However, the face of a golf club cast from a conventional titanium alloy such as 6-4 Ti needs to be chemically etched to remove the alpha case on one or both sides so that the face is durable. Such etching requires the application of hydrofluoric (HF) acid, a chemical etching solution that is difficult to handle, highly harmful to humans and other materials, an environmental pollutant, and expensive.

[0068] Faces cast from titanium alloys containing aluminum (e.g., 8.5 - 9.5% Al), vanadium (e.g., 0.9 - 1.3% V), and molybdenum (e.g., 0.8 - 1.1% Mo), optionally together with other trace alloying elements and impurities, are collectively referred to herein as "9-1-1 Ti" and can have a less significant alpha case, and compared to faces made from conventional 6-4 Ti and other titanium alloys, HF acid etching is not required or at least less necessary.

[0069] Furthermore, 9-1-1 Ti can have minimum mechanical properties of a yield strength of 820 MPa, a tensile strength of 958 MPa, and an elongation of 10.2%. These minimum properties can be significantly superior to those of typical cast titanium alloys such as 6-4 Ti, which can have minimum mechanical properties of a yield strength of 812 MPa, a tensile strength of 936 MPa, and an elongation of about 6%.

[0070] A cast golf club head that includes a face as an integral part of the body (e.g., cast simultaneously as a single cast object) can provide superior structural characteristics compared to a club head in which the face is formed separately and later attached (e.g., welded or bolted) to the front opening of the club head body. However, the advantage of having an integrally cast Ti face is mitigated by the need to remove the alpha case on the surface of the cast Ti face.

[0071] Can the club head disclosed herein, which includes an integrally cast 9-1-1 Ti face and body unit, eliminate or at least significantly reduce the drawback of having to remove the alpha case? In the case of a cast 9-1-1 Ti face, when using a conventional mold preheat temperature of 1000 °C or higher, the thickness of the alpha case can be, in some embodiments, about 0.15 mm or less, about 0.20 mm or less, or about 0.30 mm or less, for example 0.10 mm to 0.30 mm. However, in the case of a cast 6-4 Ti face, the thickness of the alpha case can be, in some examples, more than 0.15 mm, more than 0.20 mm, or more than 0.30 mm, for example about 0.25 mm to about 0.30 mm.

[0072] In some cases, the reduction in the thickness of the alpha case (e.g., 0.15 mm or less) of the 9-1-1 Ti face plate may not be thin enough to provide sufficient durability required for the face plate and avoid the need to etch away part of the alpha case with a harsh chemical etching solution such as HF acid. In such cases, before injecting the molten titanium alloy into the mold, the preheat temperature of the mold can be lowered (to less than 800 °C, less than 700 °C, less than 600 °C, and / or 500 °C or less). This can further reduce the amount of oxygen transferred from the mold to the cast titanium alloy, resulting in a thinner alpha case (e.g., less than 0.15 mm, less than 0.10 mm, and / or less than 0.07 mm). This provides better ductility and durability to the casting / face unit, which is particularly important for the face plate.

[0073] Since the alpha case in the cast 9-1-1 Ti face is thin, durability is improved, the face is sufficiently durable, and partial removal of the alpha case from the face by chemical etching becomes unnecessary. Thus, when using a mold with a particularly low preheating temperature, integrally casting the body and face using 9-1-1 Ti can remove hydrofluoric acid etching from the manufacturing process. This simplifies the manufacturing process, reduces costs, mitigates safety risks and operational hazards, and can eliminate the potential for environmental contamination by HF acid. Further, since HF acid is not introduced into the metal, the body / face, or even the entire club head, may contain little or substantially no fluorine atoms that can be defined as less than 1000 ppm, less than 500 ppm, less than 200 ppm, and / or less than 100 ppm, and the fluorine atoms present are due to impurities in the metal material used to cast the body.

[0074] Variable face thickness and face bulge and roll characteristics In certain embodiments, for example, as described in U.S. Patent Application No. 12 / 006,060 and U.S. Patents Nos. 6,997,820, 6,800,038, 6,824,475, 7,731,603, and 8,801,541, the profile of a variable thickness face can be implemented in a face plate, the entire contents of each of which are hereby incorporated by reference. Varying the thickness of the face plate generally increases the size of the COR region of the club head, commonly referred to as the sweet spot of the golf club head, and when hitting a golf ball with the golf club head, a larger area of the face plate can consistently provide a high golf ball speed and shot tolerance. Also, varying the thickness of the face plate can be advantageous for reducing the weight of the face region for redistribution to another area of the club head. For example, as shown in FIG. 9, the face plate 18 has a thickness t defined between an outer surface 22 and an inner surface 40 facing the interior cavity of the golf club head. The face plate 18 can include a central portion 42 positioned adjacent to an ideal impact location 23 on the outer surface 22. The central portion 42 can have a thickness similar to, slightly greater than, or slightly less than the thickness around the perimeter of the face plate. The face plate 18 can also include a diverging portion 44 extending radially outward from the central portion 42, which may be elliptical. The inner surface 40 may be symmetric and / or asymmetric with respect to one or more axes. The thickness t of the diverging portion 44 increases in a radially outward direction from the central portion 42. The face plate 18 includes a converging portion 46 extending through a transition portion 48 from the diverging portion 44. The thickness t of the converging portion 46 substantially decreases at a radially outer position from the transition portion 48. In some cases, the transition portion 48 is the apex between the diverging portion 44 and the converging portion 46. In other implementations, the transition portion 48 extends radially outward from the diverging portion 44 and has a substantially constant thickness t (see FIGS. 7-9).

[0075] In some embodiments, the cross-sectional profile of the faceplate 18 along any axis extending perpendicular to the faceplate at the ideal impact location 23 is substantially the same as that shown in FIGS. 7-9. In other embodiments, the cross-sectional profile can vary, for example, be asymmetric. For example, in certain implementations, the cross-sectional profile of the faceplate 18 along the z-axis of the head origin can include a central portion, a transition portion, a divergent portion, and a convergent portion as described above (see FIGS. 7-9). However, the cross-sectional profile of the faceplate 18 along the x-axis of the head origin can include a second divergent portion that extends radially from the convergent portion 46 and is coupled to the convergent portion via a transition portion. In alternative embodiments, the cross-sectional profile of the faceplate 18 along the z-axis of the head origin can include a second divergent portion that extends radially from the convergent portion and is coupled to the convergent portion, as described above with respect to the variation along the x-axis of the head origin.

[0076] In some embodiments of a golf club head having a faceplate with protrusions, the maximum faceplate thickness is greater than about 4.8 mm and the minimum faceplate thickness is less than about 2.3 mm. In certain embodiments, the maximum faceplate thickness is from about 5 mm to about 5.4 mm and the minimum faceplate thickness is from about 1.8 mm to about 2.2 mm. In more particular embodiments, the maximum faceplate thickness is about 5.2 mm and the minimum faceplate thickness is about 2 mm. The face thickness must have a thickness variation of at least 25% (thickest portion compared to the thinnest portion) across the face in order to reduce weight and achieve higher ball speeds on off-center hits.

[0077] In some embodiments of a golf club head having a face plate with a protrusion and a thin sole structure or a thin skirt structure, the maximum face plate thickness is greater than about 3.0 mm and the minimum face plate thickness is less than about 3.0 mm. In certain embodiments, the maximum face plate thickness is from about 3.0 mm to about 4.0 mm, from about 4.0 mm to about 5.0 mm, from about 5.0 mm to about 6.0 mm, or greater than about 6.0 mm, and the minimum face plate thickness is from about 2.5 mm to about 3.0 mm, from about 2.0 mm to about 2.5 mm, from about 1.5 mm to about 2.0 mm, or less than about 1.5 mm.

[0078] Figures 10 and 11 show a golf club head 4 having a shaft 3. The club head 4 includes a central face 5a, a heel 5b, a toe 5c, a crown 5d, and a sole 5e. The club head 4 further includes a club face 6 that includes a curvature from the heel 5b to the toe 5c generally referred to as a bulge 8. The club face 6 also includes a curvature from the crown 5d to the sole 5e generally referred to as a roll 9. In at least one embodiment, the combination of curvatures can provide a shape that is substantially toroidal in shape or similar to the cross-section of a torus to the club face 6. The club face 6 further includes an X-axis X that extends horizontally through the central face 5a from the heel 5b to the toe 5c, a Z-axis Z that extends vertically through the central face 5a from the crown 5d to the sole 5e, and a Y-axis Y that passes through the central face and extends horizontally within the page of FIG. 10. The X-axis X, the Y-axis Y, and the Z-axis Z are mutually orthogonal to each other.

[0079] As shown in FIG. 11, the club head 4 further has a center of gravity (CG) 5f inside the club head. The club head 4 has a CG X-axis, a CG Y-axis, and a CG Z-axis, and these axes are mutually orthogonal to each other and pass through the CG 5f so as to define a CG coordinate system. The CG X-axis and the CG Y-axis are in a horizontal plane parallel to a flat ground. The CG Z-axis is in a vertical plane perpendicular to a flat ground. In one embodiment, the CG Y-axis may coincide with the Y-axis Y, but in most embodiments, these axes do not coincide.

[0080] Figure 11 is an exaggerated depiction of club head 4 hitting golf ball B at heel 5b of the club head. This imparts a clockwise spin to golf ball B, causing the golf ball to curve to the right during flight. As described above, when golf ball B is hit at heel 5b of club head 4, the golf ball leaves club head 4 at an angle Θ with respect to the CG Y-axis of club head 4. Angle Θ merely indicates the general angle at which the ball leaves the club head and is not intended to depict or imply the actual angle with respect to the center line or the point at which that angle is measured. Angle Θ further indicates that a ball hit at the heel of the club initially moves its flight path to the left of the center line.

[0081] The method used to obtain the values in the present disclosure is the optical comparator method. Referring back to FIG. 10, club face 6 includes a series of score lines 11 that traverse the width of the club face generally along the X-axis X of club head 4. In the optical comparator method, club head 4 is mounted downward and substantially horizontally on a V-block attached to the optical comparator. Club head 4 is oriented such that score lines 11 are substantially parallel to the X-axis of the optical comparator. More precise alignment steps may also be used. Next, measurements are taken at the geometric center point 5a on the club face. Next, additional measurements are taken 20 millimeters away from the geometric center point 5a of club face 6 along the X-axis X of the club head on both sides of the geometric center point 5a, and 30 millimeters away from the geometric center point of the club face along the X-axis X of the club head on both sides of the center point. For example, by using the radius function of the machine, an arc is fitted to these five measurement points. This arc corresponds to the circumference of a circle having a given radius. This measurement of the radius is what is meant by the bulge radius.

[0082] To measure roll, the club head 4 is rotated 90 degrees so that the Z-axis Z of the club head is substantially parallel to the X-axis of the machine. The measurement is taken at the geometric center point 5a of the club face. Next, additional measurements are taken 15 millimeters away from the geometric center point 5a and along the Z-axis Z of the club face 6 on both sides of the center point, and also 20 millimeters away from the geometric center point and along the Z-axis of the club face on both sides of the center point. An arc is fitted to these five measurement points. This arc corresponds to a circumference having a given radius. This measurement of the radius is what is meant by the roll radius.

[0083] Curvature is defined as 1 / R, where R is the radius of the circle corresponding to the bulge or roll measurement arc. As an example, a bulge having a curvature of 0.020 cm -1 corresponds to a bulge measured by a bulge measurement arc that is part of a circle having a radius of 50 cm. A roll having a curvature of 0.050 cm -1 corresponds to a roll measured by a roll measurement arc that is part of a circle having a radius of 20 cm.

[0084] In some embodiments, the face plate of the disclosed club head can have the following characteristics: i) The roll curvature is from about 0.033 cm -1 to about 0.066 cm -1 and the bulge curvature is 0 cm -1 exceeds, about 0.027 cm -1 is less than, ii) The reciprocal of the bulge curvature is at least 7.62 cm greater than the reciprocal of the roll curvature, and / or iii) The ratio Ro of the bulge curvature divided by the roll curvature is greater than about 0.28 and less than about 0.75.

[0085] The use of vacuum die casting for manufacturing the club head described in this specification improves quality and reduces scrap. Furthermore, defective products due to high porosity are substantially eliminated, similar to defective products after secondary processing. Excellent surface quality is obtained, while at the same time the density and strength of the product are improved, enabling larger, thinner, and more complex castings. From the perspective of processing, the required casting pressure is low, and the tool life and mold life are extended. Also, the waste of metal or alloy due to flash is reduced or eliminated.

[0086] By utilizing the vacuum die casting method, surprisingly, the titanium body and face plate of the disclosed club head exhibit a grain size much smaller than that commonly observed in similar titanium objects made by investment casting. It has been found that the grain size of the investment casting titanium face plate is about 750 μm (micrometers), while the grain size of the disclosed titanium body / face plate has a grain size of about 100 μm. More specifically, the titanium body / face plate disclosed herein can have a grain size of less than about 400 μm, preferably less than about 300 μm, more preferably less than about 200 μm, even more preferably less than about 150 μm, and most preferably less than about 120 μm.

[0087] The titanium body / face plate disclosed herein can also exhibit a porosity much lower than that commonly observed in similar separately formed titanium face plates made by investment casting. More specifically, the titanium face plate disclosed herein can have a porosity of less than 1%, preferably less than 0.5%, and more preferably less than 0.1%.

[0088] The titanium body / face plate disclosed herein can also exhibit a yield strength much higher than that commonly observed in similar titanium face plates made by investment casting, as measured by ASTM E8.

[0089] The titanium faceplate disclosed herein can also exhibit fracture toughness similar to that commonly observed in similar titanium faceplates made by investment casting and higher than that of similar faceplates made from forged and rolled annealed products.

[0090] The titanium faceplate disclosed herein can also exhibit ductility as measured by the elongation rate reported in a tensile test defined as the maximum elongation of the gauge length divided by the original gauge length of from about 10% to about 15%.

[0091] The titanium faceplate disclosed herein can also exhibit a Young's modulus of 100 GPa ± 10%, preferably ± 5%, more preferably ± 2% when measured by ASTM E-111.

[0092] The titanium faceplate disclosed herein can also exhibit a maximum tensile strength of 970 MPa ± 10%, preferably ± 5%, more preferably ± 2% when measured by ASTM E8.

[0093] By combining the various properties described above, it is possible to manufacture a metalwood titanium club head having a titanium faceplate that is 10% thinner than similar faceplates made by conventional investment casting while maintaining strength properties that are equally good or better.

[0094] In addition to the strength characteristics of the golf club head of the present invention, in certain embodiments, the shape and dimensions of the golf club head can be formed to generate an aerodynamic shape in accordance with U.S. Patent Application Publication No. 2013 / 0123040, filed Dec. 18, 2012, by Willett et al., the entire content of which is incorporated herein by reference. The aerodynamics of the golf club head are also detailed in U.S. Pat. Nos. 8,777,773; 8,088,021; 8,540,586; 8,858,359; 8,597,137; 8,771,101; 8,083,609; 8,550,936; 8,602,909; and 8,734,269, the teachings of which are incorporated herein by reference in their entirety.

[0095] In addition to the strength characteristics of the rear body and the aerodynamic characteristics of the club head, another set of characteristics of the club head that must be controlled are the acoustic characteristics or sounds emitted when the golf club head strikes a golf ball. In a club head / golf ball impact, the striking face of the club is deformed such that vibration modes of the club head associated with the club crown, sole, or striking face are excited. The shape of most golf club heads is complex, consisting of surfaces with various curvatures, thicknesses, and materials, and accurate calculation of club head modes can be difficult. Club head modes can be calculated using computer-aided simulation tools. In the club head of the present invention, the acoustic signal generated in a ball / club impact can be evaluated as described in co-pending U.S. Patent Application No. 13 / 842,011, filed Mar. 15, 2013, the entire content of which is incorporated herein by reference.

[0096] In certain embodiments of the present invention, the golf club head may be attached to the shaft via a removable head - shaft connection assembly as described in detail by U.S. Patent No. 8,303,431, issued November 6, 2012, the entire content of which is incorporated herein by reference. Further, in certain embodiments, the golf club head not only removably connects the shaft to the head, but also incorporates the ability to adjust the loft and / or lie angle of the club by utilizing a removable head - shaft connection assembly. Such adjustable lie / loft connection assemblies are described in detail by U.S. Patent No. 8,025,587, issued September 27, 2011, U.S. Patent No. 8,235,831, issued August 7, 2012, U.S. Patent No. 8,337,319, issued December 25, 2012, as well as U.S. Patent Application Publication No. 2011 / 0312437, filed June 22, 2011, U.S. Patent Application Publication No. 2012 / 0258818, filed June 20, 2012, U.S. Patent Application Publication No. 2012 / 0122601, filed December 29, 2011, U.S. Patent Application Publication No. 2012 / 0071264, filed March 22, 2011, and co - pending U.S. Patent Application No. 13 / 686,677, filed November 27, 2012, the entire content of these patents, publications and applications being incorporated herein by reference in their entirety.

[0097] In certain embodiments, the golf club head features an adjustable mechanism provided in the sole portion to "decouple" the relationship between the face angle and the hosel / shaft loft, allowing for separate adjustment of the square loft and face angle of the golf club. For example, some embodiments of the golf club head can include an adjustable sole portion that can be adjusted relative to the club head body to raise and lower the rear end of the club head relative to the ground. Further details regarding adjustable sole portions are described in U.S. Patent No. 8,337,319, issued December 25, 2012, U.S. Patent Application Publication No. 2011 / 0152000, filed December 23, 2009, U.S. Patent Application Publication No. 2011 / 0312437, filed June 22, 2011, U.S. Patent Application Publication No. 2012 / 0122601, filed December 29, 2011, and co-pending U.S. Patent Application No. 13 / 686,677, filed November 27, 2012, the entire contents of each of which are incorporated herein by reference.

[0098] In some embodiments, the manufacturer and / or user can adjust a movable weight to adjust the position of the center of gravity of the club and use the desired performance characteristics with the golf club head. This functionality is described in more detail by U.S. Patent Nos. 6,773,360, 7,166,040, 7,452,285, 7,628,707, 7,186,190, 7,591,738, 7,963,861, 7,621,823, 7,448,963, 7,568,985, 7,578,753, 7,717,804, 7,717,805, 7,530,904, 7,540,811, 7,407,447, 7,632,194, 7,846,041, 7,419,441, 7,713,142, 7,744,484, 7,223,180, and 7,410,425, the entire contents of each of which are incorporated herein by reference in their entirety.

[0099] According to some embodiments of the golf club head described herein, the golf club head can also include a slidably repositionable weight positioned on the sole portion and / or the skirt portion of the club head. Among other advantages, the slidably repositionable weight allows the end user of the golf club to adjust the position of the CG of the club head over a range of positions with respect to the position of the repositionable weight. Further details regarding the slidably repositionable weight feature are described in U.S. Patent Nos. 7,775,905, 8,444,505, filed on May 20, 2013, U.S. Patent Application No. 13 / 898,313, and U.S. Patent Application No. 14 / 047,880, filed on October 7, 2013, the entire contents of each of which are incorporated herein by reference. Similarly, the contents of paragraphs

[0430] to

[0470] and FIGS. 93 to 101 of U.S. Patent Application Publication No. 2014 / 0080622 corresponding to U.S. Patent Application No. 13 / 956,046, filed on July 31, 2013, as well as the contents of co-pending U.S. Patent Application No. 62 / 020,972, filed on July 3, 2014, and U.S. Patent Application No. 62 / 065 / 552, filed on October 17, 2014, are also described herein, the contents of each of which are incorporated herein by reference.

[0100] According to some embodiments of the golf club head described herein, the golf club head may also include a coefficient of restitution feature that defines a gap in the body of the club, for example, positioned adjacent to the face in the sole portion. Such coefficient of restitution features are fully described by U.S. Patent Application Nos. 12 / 791,025, filed on June 1, 2010, 13 / 338,197, filed on December 27, 2011, 13 / 839,727, filed on March 15, 2013 (U.S. Patent Application Publication No. 2014 / 0274457), 14 / 457,883, filed on August 12, 2014, and 14 / 573,701, filed on December 17, 2014, the entire contents of each of which are incorporated herein by reference in their entirety.

[0101] Additional exemplary club heads Figures 20 - 36D illustrate another exemplary wood - type golf club head 200 that can include any combination of the features disclosed herein. For example, the club head body 202 and the face 270 can be cast as an integral structure from a titanium alloy as described herein. The head 200 includes a raised sole structure (see the advantages described in U.S. Patent Application Publication No. 2018 / 0185719) and includes two weight tracks 214, 216 having slidably adjustable weight assemblies 210, 212. The head 200 further includes both a crown insert 206 and a sole insert 208 (see the exploded views of FIGS. 21 and 22), and these inserts can be constructed from various lightweight materials having multi - layer fiber reinforcements arranged in a desired orientation pattern (see further details in U.S. Patent Application Publication No. 2018 / 0185719). The head 200 includes a body 202, an adjustable head - shaft connection assembly 204, a crown insert 206 attached to the upper portion of the body, a sole insert 208 attached inside the body on the lower portion of the body, a front weight assembly 210 slidably attached to the front weight track 214, and a rear weight assembly 212 slidably attached to the rear weight track 216. The head 200 includes a front seating pad or ground contact surface 226 between the front track 214 and the face 270 and a rear seating pad or ground contact surface 224 on the rear of the body on the heel side of the rear track 216, and when in the normal address position, the remainder of the sole is higher than the ground.

[0102] The head 200 has a raised sole defined by the combination of the body 202 and the sole insert 208. For example, as shown in FIGS. 22 and 27, the lower portion of the body 202 includes a toe - side opening 240, a heel - side opening 242, and a rear track opening 244, all of which are covered by the sole insert 208. The rear weight track 216 is positioned under the sole insert 208.

[0103] The head 200 also includes a toe-side cantilevered ledge 232 that extends circumferentially from the rear weight track 216 or the rear seating pad 224 around the toe region adjacent to the face, and this ledge 232 joins a toe portion 230 of the body that extends in the toe direction from the front seating pad 226. One or more optional ribs 236 can join the toe portion 230 to a raised sole adjacent to the front end of the toe-side opening 240 of the body. Three such triangular ribs are shown in FIGS. 20 and 26A.

[0104] The head 200 also includes a heel-side cantilevered ledge 234 that extends rearward from near the hosel region to the rear end of the rear seating pad 224 or the rear weight track 216. In some embodiments, the two cantilevered ledges 232 and 234 can contact and / or form a continuous ledge that extends around the rear of the head. The rear seating pad 224 can optionally include a recessed rear portion 222 (as shown in FIG. 26).

[0105] The lower portion of the body 202 that forms part of the sole can include various features, thickness variations, ribs, etc. to provide enhanced rigidity if desired, or weight reduction if less rigidity is desired. The body can include, for example, a thicker region 238 near the intersection of the two weight tracks 214, 216. The body can also include a thin ledge or seat 260 around the openings 240, 242, and the ledge 260 is configured to receive and engage the sole insert 208. The lower surface of the body can also include various internal ribs such as the ribs 262, 263, 265, and 267 shown in FIGS. 27 and 28 to enhance rigidity and acoustic effects.

[0106] At the top of the body, various features, thickness variations, ribs, etc. can be included to provide enhanced rigidity if desired or weight reduction if less rigidity is desired. For example, the body includes a thin seat region 250 around the upper opening to receive the crown insert 206. As shown in FIG. 21A, the seats 250 and 260 for the crown and sole inserts may share a common edge or be adjacent to each other around the outer periphery of the body.

[0107] Figures 35A - 35D show top views of the head 200 in various states where the crown and sole inserts are in place and / or removed. Figures 36A - 36D show the crown and sole inserts in more detail. As shown in FIGS. 36A and 36B, the sole insert 208 can have an irregular shape with a concave upper surface and a convex lower surface. The sole insert 208 can also include a notch 209 at the rear heel end to accommodate fitting around the rear seating pad 224 region where enhanced rigidity due to ground forces is required. In various embodiments, the sole insert can cover at least about 50%, at least about 60%, at least about 70%, or at least about 80% of the surface area of the sole. In another embodiment, the sole insert covers from about 50% to 80% of the surface area of the sole. The sole insert has sufficient strength and rigidity to withstand the large dynamic loads imposed on the club head while remaining relatively lightweight to contribute to a club head structure that liberates discretionary mass that can be strategically allocated elsewhere within the club head.

[0108] The sole insert 208 has a shape and size selected to cover at least the openings 240, 242, 244 at the bottom of the body and can be fixed to the frame by adhesion or other secure fixing techniques. In some embodiments, the ledge 260 may include a recess for receiving a protrusion or bump that aligns with the underside of the sole insert to further secure and align the sole insert on the frame.

[0109] Similar to the sole, the crown also has an opening 246 that reduces the mass of the body 202 and, more significantly, reduces the mass of the crown, which is the area of the head where an increase in mass has the greatest (undesirable) effect of raising the CG of the head. Along the perimeter of the opening 246, the frame includes a recessed ledge 250 for seating and supporting the crown insert 206. The crown insert 206 (see FIGS. 36C and 36D) has a geometry and size that conforms to the crown opening 246 and is secured to the body by adhesion or other secure fastening techniques so as to cover the opening 246. The ledge 260 may have a depression along the length of the ledge for receiving a protrusion or bump that mates with the underside of the crown insert to further secure and align the crown insert on the body. The crown insert may also include a forward projection 207 that extends into the front crown portion 252 of the body.

[0110] In various embodiments, the ledges of the body that receive the crown insert and the sole insert (e.g., ledges 250 and 260) may be made of the same metallic material (e.g., titanium alloy) as the body and, thus, can add a significant amount of mass to the golf club head. In some embodiments, the width of the ledge can be adjusted to achieve a desired mass contribution in order to control the mass contribution of the ledge to the golf club head. In some embodiments, if the ledge adds excessive mass to the golf club head, it may negate the weight reduction benefits of the sole insert and the crown insert, which can be made from a lighter material (e.g., carbon fiber or graphite composite material and / or polymer material). In some embodiments, the width of the ledge can range from about 3 mm to about 8 mm, preferably from about 4 mm to about 7 mm, more preferably from about 4.5 mm to about 5.5 mm. In some embodiments, the width of the ledge can be at least four times the thickness of each insert. In some embodiments, the thickness of the ledge can range from about 0.4 mm to about 1 mm, preferably from about 0.5 mm to about 0.8 mm, and more preferably from about 0.6 mm to about 0.7 mm. In some embodiments, the thickness of the ledge can range from about 0.5 mm to about 1.75 mm, preferably from about 0.7 mm to about 1.2 mm, and more preferably from about 0.8 mm to about 1.1 mm. The ledge may extend or run along the entire interface boundary between each insert and the body, although in alternative embodiments, the ledge may extend only partially along the interface boundary.

[0111] The periphery of the crown opening 246 is close to and can closely follow the periphery of the crown on the toe side, rear side, and heel side of the head 200. In contrast, the face side of the crown opening 246 can be further spaced from the face 270 region of the head. In this way, the head can have additional frame mass and reinforcement in the crown region 252 immediately behind the face 270. This region, as well as other regions adjacent to the face along the toe, heel, and sole, support the face and are subject to the relatively high impact loads and stresses due to the impact of the ball on the face. As described elsewhere herein, the frame may be made of a wide range of materials including high-strength titanium, titanium alloys, and / or other metals. The opening 246 can have a notch on the front side that mates and aligns with the crown insert protrusion 207 to assist in positioning and seating the crown insert in the body.

[0112] The front weight track 214 and the rear weight track 216 are disposed on the sole of the club head and define tracks for attaching slidable weight assemblies 210, 212 of two parts that can be fastened to the weight tracks by fastening means such as screws. The weight assemblies can take forms other than the form shown in FIG. 21A, can be attached in other ways, and can take the form of a single-part design or a multi-part design. The weight tracks allow for loosening for slidable adjustment of the weight assemblies along the tracks and then tightening in place to adjust the effective CG and MOI characteristics of the club head. For example, the CG of the club head can be moved forward or backward via the rear weight assembly 212 or in the heel or toe direction via the front weight assembly 210 to modify the performance characteristics of the club head and affect the flight of the golf ball, particularly the spin characteristics of the golf ball. In other embodiments, the front weight track 214 can instead be a front channel without a movable weight.

[0113] The sole of the body 202 is preferably integrally formed with a front weight track 214 that extends substantially parallel to and near the face of the club head and extends rearward from near the center of the front track toward the rear of the head and is substantially perpendicular to a rear weight track 216.

[0114] In the illustrated embodiment, each weight track includes only one weight assembly. In other embodiments, two or more weight assemblies can be attached to one or both of the weight tracks to provide another mass distribution capability to the club head.

[0115] By adjusting the CG via the front weight track 214 in the heel or toe direction, the performance characteristics of the club head can be modified to affect the flight of the ball, particularly the tendency of the ball to draw or fade, and / or counteract the tendency of the ball to slice or hook. By adjusting the CG via the rear weight track 216 in the forward or rearward direction, the performance characteristics of the club head can be modified to affect the flight of the ball, particularly the tendency of the ball to move upward, or resist the drop during flight due to backspin. Using two weight assemblies with the weight tracks allows for alternative adjustments and interactions between the two weights. For example, with respect to the front track 214, two independent adjustable weight assemblies can be positioned completely on the toe side, completely on the heel side, spaced apart by the maximum distance, with one weight positioned completely on the toe side and the other completely on the heel side, both positioned at the center of the weight track, or positioned in other weight configurations. As shown, with a single weight assembly within the track, the weight adjustment options are more limited, but the effective CG of the head is still adjustable along a continuum, for example, along the heel or toe direction, or in a neutral position with a weight placed at the center of the front weight track.

[0116] As shown in FIGS. 29 - 34, each weight track 214, 216 preferably has a recess with a generally rectangular shape, providing a recess track to seat and guide the weight as it slides adjustably along the track. Each track preferably includes one or more peripheral rails or ledges to define an elongated channel having a width dimension smaller than the width of the weight disposed within the channel. For example, as shown in FIGS. 29 and 30, the front track 214 includes opposing peripheral rails 288 and 284, and as shown in FIGS. 33 and 34, the rear track 216 includes opposing peripheral rails 290 and 292. In this way, the weight slides within the weight track and the rails prevent the weight from coming off the track. At the same time, the channel between the ledges allows the screw of the weight assembly to pass through the center of the outer weight element, through the channel, and then thread into the inner weight element. The ledges provide a track or rail on which the joined weight assembly slides freely, while at the same time effectively preventing the weight assembly from inadvertently slipping off the track even if the weight assembly becomes loose. In the front track 214, the inner weight member of the assembly 210 is positioned on the rails 284 and 288 within the inner recesses 280 and 286, while the outer weight member is partially seated within the recess 282 between the front rail 284 and the overhanging lip 228 of the front seating pad 226 (FIGS. 30, 31). In the rear track 216, the inner weight member of the assembly 212 is positioned on the rails 290 and 292 within the inner recesses 296 and 298, while the outer weight member can be partially seated within the recess 294 between the heel - side rail 290 and the overhanging lip 225 of the rear seating pad 224.

[0117] The weight assembly can be adjusted by loosening the screws, moving the weights along the track to a desired position, and then tightening the screws to secure the assemblies in place. The weight assemblies can also be replaced with other weight assemblies having different masses to provide additional mass adjustment options. When a second or third weight is added to the weight track, many additional weight position and distribution options are available to further fine-tune the effective CG position of the head in the heel-to-toe direction and the front-to-back direction, and combinations thereof. This also provides a wide range of adjustment of the MOI characteristics of the club head.

[0118] Either or both of the weight assemblies 210, 212 can include a three-piece assembly including an inner weight member, an outer weight member, and a fastener for coupling the two weight members together. The assembly can be clamped to a ledge at the front, rear, or side of the weight track by tightening the fastener such that the inner member contacts the inside of the ledge and the outer weight member contacts the outside of the ledge, and has a clamping force sufficient to hold the assembly stationary relative to the body throughout a golf round. The weight member and assembly can be shaped and / or configured to be inserted into the weight track by inserting the inner weight over (one or more) ledges of the usable portion of the weight track, as opposed to inserting the inner weight at an enlarged opening at one end of the weight track where the weight assembly is not configured to be fixedly located in place. This can eliminate such a wide non-functional opening at the end of the track, allowing the track to be made shorter or having a longer functional ledge width to which the weight assembly can be secured. To enable insertion of the inner weight member over a ledge into the track at the center of the track (for example), the inner weight member can be inserted at an angle not perpendicular to the ledge, such as an angled insertion. The weight member is inserted at an angle and can rotate gradually within the inner channel to be inserted over the clamp ledge. In some embodiments, the inner weight member can have a rounded, oval, oblong, arcuate, curved, or other specially shaped configuration to better enable the weight member to be inserted over a ledge into the channel at the usable portion of the track.

[0119] In the golf club head of the present disclosure, combined with the weight savings achieved by the use of a titanium alloy material and the incorporation of lightweight crown inserts and / or sole inserts, the ability to adjust the relative positions and masses of slidably adjustable weights and / or screw-adjustable weights, in further combination with the discretionary mass provided by the raised sole configuration, allows for a wide range of variations in a number of characteristics of the club head, all of which affect the final club head performance, including the position of the club head's CG, the club head's MOI value, the club head's acoustic characteristics, the club head's aesthetic appearance and subjective feel characteristics, and / or other characteristics.

[0120] In certain embodiments, the front weight track and the rear weight track have a specific track width. The track width can be measured, for example, as the horizontal distance between a first track wall and a second track wall that are substantially parallel to each other on both sides of the inner portion of the track that receives the inner weight member of the weight assembly. Referring to FIGS. 29-31, the width of the front track 214 can be the horizontal distance between the opposing walls of the inner recesses 280 and 286. Referring to FIGS. 32-34, the width of the rear track 216 can be the horizontal distance between the opposing walls of the inner recesses 296 and 298. For both the front track and the rear track, the track width can be from about 5 mm to about 20 mm, such as from about 10 mm to about 18 mm, or for example from about 12 mm to about 16 mm. According to some embodiments, the depth of the track (i.e., the vertical distance between the uppermost inner wall of the track and a virtual plane including the area of the sole adjacent to the outermost edge of the track) can be from about 6 mm to about 20 mm, such as from about 8 mm to about 18 mm, or for example from about 10 mm to about 16 mm. In the case of the front track 214, the depth of the track can be the vertical distance from the inner surface of the overhanging lip 228 to the upper surface of the inner recess 280 (FIG. 30). In the case of the rear track 216, the depth of the track can be the vertical distance from the inner surface of the overhanging lip 225 to the upper surface of the inner recess 296 (FIG. 34).

[0121] Furthermore, both the front weight track and the rear weight track have a specific track length. The track length may be measured as the horizontal distance between the opposing longitudinal end walls of the track. For both the front track and the rear track, their track lengths can be from about 30 mm to about 120 mm, such as from about 50 mm to about 100 mm, or for example from about 60 mm to about 90 mm. Additionally or alternatively, the length of the front track may be expressed as a percentage of the length of the striking face. For example, the front track can be from about 30% to about 100% of the length of the striking face, such as from about 50% to about 90% of the length of the striking face, or for example from about 60% to about 80% mm.

[0122] The above-described characteristics of the track depth, width, and length can similarly be applied to the front channel 36 of the club head 10.

[0123] In FIGS. 30 and 34, it can be seen that the lips 228, 225 of the front and rear seating pads extend onto or overhang their respective weight tracks, restricting the track openings and helping to retain the weight(s) within the track.

[0124] Referring to FIG. 34, the sole region on the rear seating pad 224 on the heel side of the rear track 216 is significantly lower in vertical distance than the sole region on the toe side (the bottom 292 of the ledge) when the head is in the address position relative to the ground plane. This can be considered a head having a "sunken sole" structure or a "raised sole" structure where a portion of the sole is positioned lower (e.g., on the heel side) relative to another portion of the sole (e.g., on the toe side). In other words, a portion of the sole (e.g., most of the sole excluding the rear seating pad 224) is raised relative to another portion of the sole (e.g., the rear seating pad). The same is true for the front track 214 where the front seating pad 226 and its lip 228 are significantly lower than the rear side of the front track as shown in FIG. 30 in the normal address position.

[0125] In one embodiment, the vertical distance between the level of the ground contact surface of the seating pad and the adjacent surface of the raised sole portion may range from about 2 to 12 mm, preferably from about 3 to 9 mm, more preferably from about 4 to 7 mm, and most preferably from about 4.5 to 6.5 mm. In one example, the vertical distance is about 5.5 mm.

[0126] Figures 37-48 illustrate another exemplary golf club head 400 having a face portion that is integrally cast as a single unit with the front portion of the club head body and forms a cup-shaped unit (referred to herein as cup 402) that includes the face portion, hosel, and the front portions of the crown, sole, toe, and heel. However, the rear portion of the body (referred to herein as ring 404) is formed separately and later attached to cup 402 to form the club head body. The combination of cup 402 and ring 404 is referred to herein as the body of club head 400. Next, crown insert 406 and sole insert 408 can be attached to the body to form club head 400. In some embodiments, there is no sole opening or sole insert and the rear ring completely surrounds the sole. In some embodiments, the sole insert can be made of a metal material, composite material, and / or other materials.

[0127] Figures 37 and 38 illustrate assembled club head 400 including cup 402, ring 404, crown insert 406, and sole insert 408. Head-shaft connection assembly 410 can be coupled to hosel 412. Cup 402 and ring 404 can include a metal material such as a titanium alloy or steel, while inserts 406 and 408 can include a low density material such as a carbon fiber reinforced composite material. Any of the other materials disclosed herein can be used for club head 400. The cup and ring may be made of the same material (e.g., the same titanium alloy), or the ring may be made of a different material than the cup (e.g., a steel ring and a titanium alloy cup, or two different titanium alloys).

[0128] Figures 39 and 40 show how the ring 404 is coupled to the cup 402 at the toe and heel junction 420 to form an annular body having an upper crown opening and a lower sole opening. The ring 404 can include a toe and heel engagement end 422 that extends rearward of the cup 402 and a toe and heel engagement end 424 that extends forward and meshes with the toe and heel engagement end 422 to form the junction 420. In the illustrated example, the ring has male protrusions that mesh with female notches within the cup. However, these junctions can be reversed with male protrusions on the cup and female notches on the ring. In other embodiments, any other suitable engagement shape can be used within the junction 420 to couple the ring to the cup. The junction 420 can be formed by any suitable means such as welding, brazing, adhesives, mechanical fasteners, and the like.

[0129] In some embodiments, the junction 420 can be positioned a sufficient distance from the strike face to avoid potential failure due to the severe impact that a golf club receives when hitting a golf ball. For example, in some embodiments, the junction 420 can be spaced at least 20 mm, at least 30 mm, at least 40 mm, at least 50 mm, at least 60 mm, and / or 20 mm to 70 mm rearward of the center plane of the club head when measured along the y-axis (front-to-back direction).

[0130] Figure 41 shows how the inserts 406 and 408 can be joined to the body to cover the crown opening and the sole opening and surround the internal cavity of the club head. The crown insert 406 can be coupled to a crown ledge 426 of a body extending around the crown opening, and the sole insert 408 can be coupled to a sole ledge 428 of a body extending around the sole opening. Ledges 426 and 428 can be formed from a combination of both the cup 402 and the ring 404, where the cup includes the front portion of the ledge and the ring includes the rear portion of the ledge. Ledges 426 and 428 can be offset inwardly from the surrounding outer surface such that there is a space to receive the insert with the outer surface of the insert being flush or coplanar with the surrounding outer surface of the cup / ring body. The ring 404 can also include a protrusion 430 extending downwardly and forwardly from the rear portion of the ring and forming a part of the sole ledge 428 that helps support the sole insert 408 and increase rigidity.

[0131] In some embodiments, the ring 404 can include a mass pad of increased thickness, such as at the protrusion 430 or elsewhere, which applies a rearward load to the golf club, moves the center of mass rearward, and increases the MOI about the z - axis and x - axis. Such a rearward load can also be achieved by additional weight members coupled to the rear ring, such as removable, replaceable, and / or adjustable weight members coupled to the rear of the ring. For example, the protrusion 430 or other portions of the ring 404 can include openings, tracks, or other weight member receiving features, such as threaded openings. FIG. 47 shows an example of two weight ports 431 and 433 that can receive such adjustable weight members. Two or more weight members can also be coupled to the rear ring simultaneously. The mass pad or the (one or more) weight members can include a material of relatively high density, such as tungsten or steel.

[0132] In some embodiments, the cup 402 can include a weight pad, such as weight pad 432 shown in the figures, in the sole region to lower the center or mass and / or move the center of mass forward. In some embodiments, the cup 402 can include one or more additional weight members coupled to the sole of the cup, such as within or near the weight pad 432 and / or behind the slot 418, for example one or more removable, interchangeable, and / or adjustable weight members coupled to the cup. For example, the weight pad 432 or other portions of the cup 402 can include one or more openings, such as threaded openings, tracks, or other weight member receiving features. Two or more weight members can also be coupled to the cup simultaneously. The (one or more) weight members can include materials that are relatively denser than the cast cup material, such as tungsten or steel. In some embodiments, the cup and ring can have mating weight ports that allow for exchanging weight members between a rear ring position and a lower cup position, providing an adjustment function option to change the mass characteristics of the club head. In some such examples, a group of interchangeable weights, such as weights including 1 - 3g and 8 - 15g, can be provided in the club head, and these weights can be coupled to the weight ports of the rear ring or the sole of the cup, enabling a higher MOI (heavier weight at the rear) or lower spin (heavier weight at a lower forward position), or other combinations and mass characteristics.

[0133] Figures 44-47 show in more detail the body formed by the joined cups 402 and 404 without the inserts 406 and 408, from several perspectives. Figure 44 is a front view showing the integral face 434. Figure 45 is a heel side view. Figure 46 is a top view showing the front crown portion 436, the front toe portion 440, and the front heel portion 442, which are part of the cup 402, as well as the toe-heel junction 420 and the crown ledge 426 that receives the crown insert 406. Figure 47 is a bottom view showing the front sole portion 438 that includes the sole slot 418 extending into the internal cavity of the club head and the ledge 428 that receives the sole insert 408. Also shown in Figure 47 are an exemplary rear weight port 431 disposed within the ring protrusion 430 and an exemplary sole weight port disposed within the cup 402 behind the slot 418 in the region of the mass pad 432. In other embodiments, such weight ports can be disposed in other parts of the cup or ring, such as the very rear of the ring, and there can be more than three such weight ports. The weight ports are threadable and can receive adjustable weight members, enabling adjustment of the center of mass and MOI characteristics of the club head.

[0134] The cup 402 is shown in more detail in FIGS. 42 and 43. The rear face of the face 434 is shown in FIG. 43. As described elsewhere in this specification, the rear portion of the face 434 can be formed to have various complex shapes and thickness profiles and can be easily accessed from the rear for machining, etching, material removal, and / or other post-casting treatments before the ring 404 is attached to the cup 402. FIG. 43 also shows a weight pad 432 on the sole portion 438 of the cup. The weight pad 432 can include a thickened portion of the sole with increased mass, which significantly affects the overall mass characteristics of the club head. The weight pad 432 can have a central notch with greater mass on the center toe side and heel side to enhance the mass and MOI characteristics. Detailed information regarding the weight pad 432, alternative weight pad shapes and embodiments, and related characteristics can be found in U.S. Patent Application Publication No. 2018 / 0126228, published on May 10, 2018, which is hereby incorporated by reference in its entirety.

[0135] FIG. 48 shows a head-shaft connection assembly 410 that allows the hosel 412 of the head 400 to be coupled to the shaft in a plurality of selectable orientations, enabling adjustment of the loft angle, lie angle, and / or face angle of the assembled golf club in a normal address position. The assembly 410 can include various components such as the sleeve 450, ferrule 452,... hosel insert 454, fastener 456, and washer 458 shown in FIG. 48. Detailed information regarding adjustable head-shaft connection assemblies can be found in U.S. Patent No. 9,033,821, issued on May 19, 2015, which is hereby incorporated by reference in its entirety.

[0136] Figures 49 and 50 show a part of a method for manufacturing a golf club head, specifically, a part of a method for manufacturing a mold for casting a front cup 402 of a club head 400. FIG. 49 shows a wax cup 500 that is a combination of a wax cup frame 502 and a wax face 504. The wax cup frame 502 and the wax face 504 are formed separately, and then the wax face is placed within a slightly larger-sized face opening in the wax cup frame 502. Next, hot liquid wax is added to the joint, and it is cooled to fuse the face to the frame, whereby the two wax pieces can be wax welded around an annular joint 506. Additional hot wax fills the joint 506 and joins the wax cup frame 503 and the wax face 504 to a single integral wax cup 500. After the wax has cooled, excess wax can be removed from the front and rear of the welded joint 506. In some embodiments, the wax face 504 can include a prong 508 that extends radially outward and contacts the front face of the wax cup frame 502 to help set the depth of the wax face 504 relative to the wax cup frame, such that the resulting front face of the wax cup 500 is uniform and smooth across the joint 506. The wax prong 508 can be removed after the wax welding method.

[0137] FIG. 50 shows another example of a wax cup 510 formed by wax welding both a wax cup frame 512 and a wax face 514 together via wax added around a joint 516 and helping to set the depth of the wax face at an opening of the wax cup frame using optionally a wax plunger 518 of the wax face. In this example, the wax cup 510 includes additional protrusions 520 that create additional gates within the resulting mold to assist the molten metal to flow uniformly towards the face portion of the mold. The wax cups 500 and 510 can also include gate-making portions at other locations, such as near the heel side near the hozel, the back side of the face, and / or other locations as shown.

[0138] Forming a wax cup from two separate wax pieces (such as in FIGS. 49 and 50, for example) can facilitate the creation of more complex shapes for the wax cup, simplify the formation of several different shaped embodiments, and enable them to be formed in a more rapid and cost - effective manner. Starting from two separate wax pieces, the tool and forming process for the wax frame are decoupled from the tool and forming process for the wax face. With respect to wax cup 500, the same wax cup frame 502 (and the same tool) can be combined with any of several different shaped wax faces 504 to produce a corresponding number of different wax cups, which means that only the tool for the wax face needs to be changed to generate different wax cups. For example, a manufacturer can produce two identical wax frames 502 and then combine one wax frame with a first wax face and the second wax frame with a second wax face having a thickness profile different from the first wax face. These two different wax cups, along with the resulting molds and the metal cups of the final products, can be measured, compared, tested, etc. For various exemplary face thickness profiles and related descriptions herein, refer to FIGS. 51 - 54. Thus, using a two - part wax cup forming process can provide advantages in rapid prototyping as well as other manufacturing and development efficiencies.

[0139] Also, starting from two separate wax pieces increases the efficiency in forming a large number of wax pieces because each wax piece is smaller and can be manufactured in a greater number per batch on the same tree.

[0140] Once a wax cup (e.g., 500 or 510) is fabricated, a mold can be formed using this wax cup for casting a metal cup (e.g., cup 402). The mold can include a ceramic material and / or any suitable material for casting a metal cup. When the mold is formed around the wax cup, the wax can be melted and discharged from the mold. Thereafter, various subsequent steps can be applied, including adding gate treatment and / or surface treatment to the mold, to prepare the mold for casting. Further, several cup molds can be combined into one mold tree to cast several metal cups simultaneously. After the mold is prepared, molten metal can be introduced into the mold to cast the metal cup. Thereafter, the mold can be opened or removed to access the cast metal cup. The cast metal cup can be formed of any suitable metal or metal alloy including a titanium alloy (any suitable metal material disclosed herein can be used for the cast cup).

[0141] After casting the metal cup, a portion of the cast cup can be machined or modified to remove a portion of the cast cup as desired. As an example, the front face of the face portion of the cup can be machined to add a horizontal score line and / or create a more accurate texture, curvature, and twist. In another example, the back face of the face portion of the cup can be machined to modify the thickness profile across the height and width of the face portion and generate a desired variable thickness profile across the face portion. The front and / or back faces of the face portion of the cast cup can also be machined or chemically etched (e.g., using hydrofluoric acid) to remove some or all of the alpha case layer formed during the casting process (e.g., in the case of a titanium alloy) without making the face portion more brittle and enhancing the durability of the face portion.

[0142] Assuming that the material is removed after casting from the face portion of the cup, the face portion of the cup can be cast with an extra thickness of material such that a desired amount of material and a desired thickness profile remain after the post-casting material removal.

[0143] As shown in FIGS. 39 and 40 and as described above, the cup 402 and the ring 404 are formed separately (e.g., cast) and then combined together (e.g., welded, brazed, adhesively bonded, mechanically fastened, etc.) at the joint 420 to form a metal club head body that functions as a rigid frame for receiving other components to form the golf club head 400. One advantage of this method of fabricating the club head body from separate cups 402 and rings 404 is that the absence of a rear ring portion provides better access for post-casting machining, chemical etching, and / or other post-casting modifications to the rear face of the face portion of the cup 402. For example, when the ring 404 is absent, there is more space for cutting tools, milling machines, CNC machines, drill bits, or other tools to access the entire rear face of the face portion of the cup 402. After such post-casting modifications are performed on the cup 402, the ring 404 can be attached to the cup and the remainder of the club head can be assembled.

[0144] Another advantage of casting the cup and ring separately is that each casting piece is smaller than the combined body, allowing for greater efficiency when casting multiple numbers of each of the ring and cup pieces per batch on the same tree. Also, since the same ring piece can be used with a variety of differently shaped cup pieces, only the tools for the cup pieces need to be changed to accommodate changes to the club head body or to produce several different variations of club heads with different cup / face shapes.

[0145] FIG. 51 shows an exemplary rear view of a face portion of a cast cup 600 similar to cup 402, with the hosel / heal to the left and the toe to the right, as viewed from the rear. FIGS. 52 and 53 show another exemplary face portion 700 having a variable thickness profile, and FIG. 54 shows yet another exemplary face portion 800 having a variable thickness profile. As a result of the casting method and any post-casting modifications to the face portion, the face portion of the cast cup can have a wide variety of novel thickness profiles. Instead of forming a face plate from a flat rolled metal sheet in a conventional process, by casting the face into the desired shape, the face can be made in a more diverse shape and can have different material properties such as different grain orientations and chemical impurity contents, which can provide advantages for golf performance and manufacturing.

[0146] In a conventional process, the face plate is formed from a flat metal sheet having a uniform thickness. Such a metal sheet is typically rolled along one axis to reduce its thickness to a constant uniform thickness across the sheet. This rolling process can impart a grain orientation to the sheet that creates different material properties in the rolling axis direction compared to the direction perpendicular to the rolling direction. This variation in material properties can be undesirable and can be avoided by using the disclosed casting method for making the face portion.

[0147] Furthermore, since a conventional face plate starts as a flat sheet of uniform thickness, the thickness of the entire sheet must be at least as thick as the maximum thickness of the face plate of the desired final product, which requires removing and wasting much of the starting sheet material and increasing the material cost. In contrast, with the disclosed casting method, the face portion is initially formed very close to the final shape and mass, and very little material is removed and wasted. This saves time and cost.

[0148] Furthermore, in the conventional process, the initial flat metal sheet has to be bent in a special process to impart the desired bulge and roll curvature to the faceplate. Such a bending process is not necessary when using the disclosed casting method.

[0149] The unique thickness profiles shown in FIGS. 51 - 54 are made possible using the disclosed casting method and were previously impossible to achieve using conventional processes where a metal sheet of uniform thickness is attached to a lathe or similar machine and rotated to produce a variable thickness profile across the back of the faceplate. In such a turning process, the applied thickness profile has to be symmetric about the central axis of rotation, which limits the thickness profile to a composition of concentric annuli each having a uniform thickness at any given radius from the central point. In contrast, no such limitation is imposed when using the disclosed casting method, and more complex face shapes can be produced.

[0150] By using the casting method disclosed herein, a number of the disclosed club heads can be manufactured faster and more efficiently. For example, over 50 cups 402 can be cast simultaneously on a single casting tree, whereas it would take much longer and require more resources to produce a new face thickness profile one at a time on a faceplate using a conventional milling process using a lathe.

[0151] In FIG. 51, the rear face surface of the casting cup 600 includes an asymmetric variable thickness profile, which shows only one example of the various variable thickness profiles made possible using the disclosed casting method. The center 602 of the face can have a center thickness, and the thickness of the face can gradually increase as it moves radially outward from the center across the inner blend region 603 to the maximum thickness ring 604, which can be circular. The thickness of the face can gradually decrease as it moves radially outward from the maximum thickness ring 604 across the variable blend region 606 to the second ring 608, which can be non-circular such as elliptical. The thickness of the face can gradually decrease as it moves radially outward from the second ring 608 across the outer blend region 609 to the heel and toe regions 610 of a constant thickness (e.g., the minimum thickness of the face portion), and / or to the radially peripheral region 612 that defines the extent of the face portion where the face transitions to the remainder of the casting cup 600.

[0152] The second ring 608 itself can have a variable thickness profile such that the thickness of the second ring 608 varies as a function of the circumferential position around the center 602. Similarly, the variable blend region 606 can have a thickness profile that varies as a function of the circumferential position around the center 602 and provides a transition in thickness from the maximum thickness ring 604 to the variable and thinner second ring 608. For example, the variable blend region 606 to the second ring 608 can be divided into eight sectors, including a top region A, a top toe region B, a toe region C, a bottom toe region D, a bottom region E, a bottom heel region F, a heel region G, and a top heel region H, labeled A - H in FIG. 51. These eight regions can have different angular widths as shown, or each can have the same angular width (e.g., one - eighth of 360 degrees). Each of the eight regions can have its own thickness variation from a common maximum thickness adjacent to the ring 604 to a different minimum thickness in the second ring 608. For example, the second ring can be thicker in regions A and E, thinner in regions C and G, and have intermediate thicknesses in regions B, D, F, and H. In this example, the thicknesses of regions B, D, F, and H can vary along both the radial direction (thinning as moving radially outward) and the circumferential direction (thinning as moving from regions A and E towards regions C and G).

[0153] An example of the casting cup 600 can have the following thicknesses, 3.1 mm at the center 602, 3.3 mm at the ring 604, and the second ring 608 can vary from 2.8 mm in region A to 2.2 mm in region C, to 2.4 mm in region E, to 2.0 mm in region G, and to 1.8 mm in the heel and toe region 610.

[0154] Figures 52 and 53 show the rear face surface of another exemplary casting face portion 700 that includes an asymmetric variable thickness profile. The center 702 of the face can have a center thickness, and the thickness of the face can gradually increase as it moves radially outward from the center across the inner blend region 703 to the maximum thickness ring 704, which can be circular. The thickness of the face can gradually decrease as it moves radially outward from the maximum thickness ring 704 across the variable blend region 705 to the outer region 706, which consists of a plurality of wedge-shaped sectors A - H having various thicknesses. As best shown in FIG. 53, sectors A, C, E, and G can be relatively thick, and sectors B, D, F, and H can be relatively thin. The outer blend region 708 surrounding the outer region 706 has a thickness transition to a peripheral ring 710 that has a relatively small but constant thickness from the variable sectors. The outer region 706 can also include blend regions between each of the sectors A - H where the thickness gradually transitions from one sector to the adjacent sector.

[0155] An example of the face portion 700 can have the following thicknesses: 3.9 mm at the center 702, 4.05 mm at the ring 704, 3.6 mm in region A, 3.2 mm in region B, 3.25 mm in region C, 2.05 mm in region D, 3.35 mm in region E, 2.05 mm in region F, 3.00 mm in region G, 2.65 mm in region H, and 1.9 mm at the peripheral ring 710.

[0156] FIG. 54 shows the back side of another exemplary cast face portion 800 that includes an asymmetric variable thickness profile having a target thickness offset toward the heel side (left side). The center 802 of the face has a center thickness, and from the toe / top / bottom, the thickness gradually increases to an inner ring 804 having a thickness greater than the center across the inner blend region 803. The thickness then moves radially outward and decreases across a second blend region 805 to a second ring 806 having a thickness thinner than that of the inner ring 804. The thickness then moves radially outward and decreases across a third blend region 807 to a third ring 808 having a thickness thinner than that of the second ring 806. The thickness then moves radially outward and decreases across a fourth blend region 810 to a fourth ring 811 having a thickness thinner than that of the third ring 808. The toe end region 812 merges with an outer peripheral portion 814 having a relatively thin thickness across an outer blend region 813.

[0157] On the heel side, the thickness is offset by a set amount (e.g., 0.15 mm) to be slightly thicker than the corresponding region on the toe side. The thickening region 820 (dashed line) provides a transition where all thicknesses gradually increase toward the thicker offset region 822 (dashed line) on the heel side. In the offset region 822, the ring 823 is thicker than the heel-side ring 806 by a set amount (e.g., 0.15 mm), and the ring 825 is thicker than the ring 808 by the same set amount. The blend regions 824 and 826 move radially outward and the thickness gradually decreases, being thicker than the corresponding blend regions 807 and 810 on the toe side, respectively. In the thickening region 820, the thickness of the inner ring 804 gradually increases toward the heel.

[0158] An example of the face portion 800 can have the following thicknesses: 3.8 mm at the center 802, 4.0 mm at the inner ring 804, thickening up to 4.15 mm across the thickening region 820, 3.5 mm at the second ring 806 and 3.65 mm at the ring 823, 2.4 mm at the third ring 808 and 2.55 mm at the ring 825, 2.0 mm at the fourth ring 811, and 1.8 mm at the peripheral ring 814.

[0159] The targeted offset thickness profile shown in FIG. 54 can help provide a desirable characteristic time (CT) profile across the face. Thickening the heel side, for example, can help avoid having a CT spike on the heel side of the face, which can help avoid having a CT profile that is non - compliant across the face. Such an offset thickness profile can be applied similarly to the toe side of the face, or to both the toe side and the heel side of the face, to avoid CT spikes on both the heel side and the toe side of the face. In other embodiments, the offset thickness profile can be applied towards the upper side and / or the lower side of the face.

[0160] Various other variable face thickness profiles can be manufactured using the disclosed methods including those disclosed in U.S. Patent Application No. 12 / 006,060, and U.S. Patents Nos. 6,997,820, 6,800,038, 6,824,475, 7,731,603, 8,801,541, 9,943,743, and 9,975,018, the entire contents of each of which are hereby incorporated by reference in their entirety. For example, U.S. Patent No. 9,975,018 discloses an example of a striking face that includes localized hardened regions such as an inverted cone or “donut” shaped thickness profile offset from the center of the face, whereby the launch conditions of a golf ball struck by the clubhead are altered, in whole or in part, to correct, overcome, or prevent the occurrence of rightward / leftward deviation. In particular, the localized hardened regions are positioned on the hitting face such that a golf ball struck under typical conditions does not impart leftward and / or rightward side spin to the golf ball.

[0161] All of the disclosed face thickness profiles can be enabled by the casting methods disclosed herein. Such configurations are not possible using conventional turning processes that remove material in a concentric pattern from the rear of an originally flat face plate.

[0162] In some embodiments of golf clubheads, the face plate can be cast individually and then welded to the front opening of the clubhead frame. When the face plate is welded to the front opening of the frame, typically, excess material is created around the weld, and this excess material must be removed after the welding process to smooth the transition between the face plate and the frame. This process can be avoided by casting the entire cup, including the face and the front frame, as a single casting unit as disclosed herein.

[0163] However, casting the faceplate separately can offer advantages over casting the entire cup as a single unit. For example, post-processing of the cast faceplate is much easier compared to post-processing of the face surface when the faceplate is part of the cup. FIGS. 55 and 56 show the front 902 and rear 904 of an exemplary cast faceplate 900. In particular, it is much easier to access all parts of the rear surface of the cast faceplate compared to the rear face surface of the cast cup. There is unlimited space to approach the cast faceplate with tools for the desired post-casting process because there are no interfering parts such as soles, crowns, toes, heels, hosels, etc. Also, the cast faceplate can be brought closer to the exact final shape of the faceplate, resulting in less material removal and less work required to correct the face after casting. For example, the faceplate can be cast with less than 0.5 mm, less than 0.4 mm, less than 0.3 mm, and / or less than 0.2 mm of excess material on each side of the face that is removed after casting. This is equivalent to less waste being removed compared to machining the faceplate from a flat sheet of rolled metal. The front of the cast face can be machined to remove some or all of the alpha case layer, achieve the correct bulge, roll and twist curvature, and / or add score lines. The rear of the cast face can be machined to remove some or all of the alpha case layer and achieve the correct variable thickness profile across the face. As described elsewhere in this specification, the casting process allows for a much more complex and asymmetric thickness profile as opposed to the 360-degree concentric symmetry required by conventional face sheet turning processes.

[0164] A cast golf club head that includes a face as an integral part of the body (e.g., cast simultaneously as a single cast object) can provide superior structural characteristics compared to a club head where the face is formed separately and later attached (e.g., welded or bolted) to the front opening of the club head body. However, the advantage of having an integrally cast Ti face is mitigated by the need to remove the alpha case on the surface of the cast Ti face.

[0165] The club heads disclosed herein that include an integrally cast titanium alloy face and body unit (e.g., a cast cup) can eliminate or at least significantly reduce the disadvantage of having to remove the alpha case. In a cast 9-1-1 Ti face, when using a mold preheat temperature of 1000 °C or higher, the alpha case thickness can be, in some embodiments, about 0.10 mm or less, 0.15 mm or less, about 0.20 mm or less, or about 0.30 mm or less, e.g., 0.10 mm to 0.30 mm. However, in a cast 6-4 Ti face, the alpha case thickness can be, in some examples, greater than 0.10 mm, greater than 0.15 mm, greater than 0.20 mm, or greater than 0.30 mm, e.g., about 0.25 mm to about 0.30 mm. In some embodiments, the alpha case thickness can be as low as about 0.1 mm and up to 0.15 mm while desirably providing a sufficiently durable product having a high CT time across the entire face. In some embodiments, the alpha case at the rear of the face at the geometric center of the face can have a thickness of less than 0.30 mm and / or less than 0.20 mm, which can be achieved without chemically etching the surface after formation.

[0166] Other titanium alloys that can be used to form either the impact face and / or the club head described herein can include titanium, aluminum, molybdenum, chromium, vanadium, and / or iron. For example, in a representative embodiment, the alloy can be an alpha-beta titanium alloy that includes 6.5 wt% to 10 wt% Al, 0.5 wt% to 3.25 wt% Mo, 1.0 wt% to 3.0 wt% Cr, 0.25 wt% to 1.75 wt% V, and / or 0.25 wt% to 1 wt% Fe, with the balance being Ti (in one example, sometimes referred to as the "1300" titanium alloy).

[0167] In another representative embodiment, the alloy can include 6.75 wt% to 9.75 wt% Al, 0.75 wt% to 3.25 wt% or 2.75 wt% Mo, 1.0 wt% to 3.0 wt% Cr, 0.25 wt% to 1.75 wt% V, and / or 0.25 wt% to 1 wt% Fe, with the balance being Ti.

[0168] In another representative embodiment, the alloy can include 7 wt% to 9 wt% Al, 1.75 wt% to 3.25 wt% Mo, 1.25 wt% to 2.75 wt% Cr, 0.5 wt% to 1.5 wt% V, and / or 0.25 wt% to 0.75 wt% Fe, with the balance being Ti.

[0169] In another representative embodiment, the alloy can include 7.5 wt% to 8.5 wt% Al, 2.0 wt% to 3.0 wt% Mo, 1.5 wt% to 2.5 wt% Cr, 0.75 wt% to 1.25 wt% V, and / or 0.375 wt% to 0.625 wt% Fe, with the balance being Ti.

[0170] In another representative embodiment, the alloy can include 8 wt% Al, 2.5 wt% Mo, 2 wt% Cr, 1 wt% V, and / or 0.5 wt% Fe, with the balance being Ti. Such a titanium alloy can have the formula Ti-8Al-2.5Mo-2Cr-1V-0.5Fe. As used herein, reference to "Ti-8Al-2.5Mo-2Cr-1V-0.5Fe" refers to a titanium alloy containing the elements mentioned in any of the above ratios. Certain embodiments can also include trace amounts of K, Mn, and / or Zr, and / or various impurities.

[0171] Ti-8Al-2.5Mo-2Cr-1V-0.5Fe can have minimum mechanical properties of a yield strength of 1150 MPa, a maximum tensile strength of 1180 MPa, and an elongation of 8%. These minimum properties can be 6-4 having the above-described minimum mechanical properties. It can be significantly superior to other cast titanium alloys including Ti and 9-1-1 Ti. In some embodiments, Ti-8Al-2.5Mo-2Cr-1V-0.5Fe has a tensile strength of about 1180 MPa to about 1460 MPa, a yield strength of about 1150 MPa to about 1415 MPa, an elongation of about 8% to about 12%, a modulus of elasticity of about 110 GPa, a density of about 4.45 g / cm 3 and a hardness of about 43 on the Rockwell C scale (43 HRC). In certain embodiments, the Ti-8Al-2.5Mo-2Cr-1V-0.5Fe alloy can have a tensile strength of about 1320 MPa, a yield strength of about 1284 MPa, and an elongation of about 10%.

[0172] In some embodiments, a cup having a striking face and / or a face portion can be cast from Ti-8Al-2.5Mo-2Cr-1V-0.5Fe. In some embodiments, the striking face and the club head body can be integrally formed or cast from Ti-8Al-2.5Mo-2Cr-1V-0.5Fe depending on the specific desired properties.

[0173] The mechanical parameters of the above Ti-8Al-2.5Mo-2Cr-1V-0.5Fe can provide surprisingly excellent performance compared to other existing titanium alloys. For example, due to the relatively high tensile strength of Ti-8Al-2.5Mo-2Cr-1V-0.5Fe, it can be shown that a cast striking face containing this alloy has less deflection per unit thickness when hitting a golf ball compared to other alloys. This is particularly beneficial for metalwood-type clubs configured to hit the ball at high speeds because the high tensile strength of Ti-8Al-2.5Mo-2Cr-1V-0.5Fe results in less deflection of the striking face, reducing the tendency of the striking face to flatten with repeated use. As a result, the striking face can maintain its original bulge, roll, and "twist" dimensions over long-term use, including by advanced and / or professional golfers who tend to hit the ball at particularly high club speeds.

[0174] Any of the embodiments disclosed herein can include a face portion having a twisted striking face such that the upper toe portion of the striking face is more open than the lower toe portion of the striking face and the lower heel portion of the striking face is more closed than the upper heel portion of the striking face. Detailed information regarding golf club heads having a twisted striking face can be found in U.S. Patent No. 9,814,944, U.S. Patent Provisional Application No. 62 / 687,143, filed June 19, 2018, and U.S. Patent Application No. 16 / 160,884, filed October 15, 2018, all of which are hereby incorporated by reference in their entirety. Any of these twisted face technologies disclosed in these incorporated references can be implemented in the club heads disclosed herein in any combination with the technologies disclosed herein.

[0175] The technology disclosed herein can be implemented for any type of golf club head, including, but not limited to, the disclosed examples of drivers, fairways, rescue clubs, hybrids, utility clubs, irons, wedges, and putters.

[0176] For the purposes of this description, specific aspects, advantages, and novel features of embodiments of the present disclosure are described herein. The disclosed methods, apparatuses, and systems should not be construed as limiting in any sense. Instead, the present disclosure is directed to all novel and non-obvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with each other. The methods, apparatuses, and systems are not limited to any specific aspect or feature or combination thereof, and the disclosed embodiments do not require the presence of any one or more specific advantages or the solving of any problems.

[0177] Although some operations of the disclosed embodiments are described in a particular sequential order for convenient presentation, it should be understood that this description method includes rearrangement unless a particular ordering is required by the specific language described herein. For example, operations described sequentially may in some cases be rearranged or performed simultaneously. Further, for simplicity of discussion, the accompanying figures may not show various ways in which the disclosed methods can be used in combination with other methods.

[0178] As used in this application and the claims, the singular forms "a", "an", and "the" include the plural unless the context clearly dictates otherwise. Also, the term "includes" means "comprises". Further, the terms "coupled" and "associated" generally mean electrical, electromagnetic, and / or physically (e.g., mechanically or chemically) coupled or connected and do not exclude the presence of intermediate elements between the coupled or associated items in the absence of a specific antonym.

[0179] In some instances, a value, procedure, or apparatus may be referred to as "lowest", "best", "minimum", etc. It should be understood that such descriptions are intended to indicate that a selection can be made from among a number of options, and that such a selection may not be better, smaller, or more preferred than other selections.

[0180] In this specification, specific terms such as "upper", "lower", "upper part", "lower part", "horizontal", "vertical", "left", "right", etc. can be used. These terms, when applicable, are used to make the description somewhat clearer when dealing with relative relationships. However, these terms do not mean absolute relationships, positions, and / or orientations. For example, with respect to an object, just by rotating the object, the "upper" surface can be made the "lower" surface. Nevertheless, the object remains the same object.

[0181] Considering the many possible embodiments to which the principles of the present disclosure can be applied, it should be recognized that the illustrated embodiments are merely preferred examples and should not be construed as limiting the scope of the present disclosure. It will be apparent that various modifications can be made thereto without departing from the broader spirit and scope of the described present disclosure. Accordingly, the present specification and drawings should be regarded in an illustrative rather than a limiting sense. Therefore, the scope of the present disclosure is at least as broad as the following claims. Accordingly, we claim all that falls within these claims.

Description of Reference Numerals

[0182] 2 Golf club head 3 Shaft 4 Golf club head 5a Center face, geometric center point 5b Heel 5c Toe 5d Crown 5e Sole 6 Club face 8 Bulge 9 rolls 10 body 11 score line 12 crown 14 sole 16 skirt 18 face plate 20 hosel 22 hitting surface, outer surface 23 impact position 24 hosel bore 26 heel part 28 toe part 30 front part 32 rear part 40 inner surface 42 central part 44 diverging part 46 converging part 48 transition part 50 center of gravity (CG) 60 origin 65 origin z-axis 70 origin x-axis 75 origin y-axis 85 CG z-axis 90 CG x-axis 95 CG y-axis 150 initial pattern 152 main gate 154 assistant gate 156 flow channel 160 cluster 162 graphite receptor 164 graphite cross spoke 166 runner 168 mold cavity 170 crucible 172 injection cup 180 cluster 184 shell runner 182 receptor 186, 188 mold cavity 200 golf club head 202 club head body 204 head-shaft connection assembly 206 Crown Insert 207 Front Projection 208 Sole Insert 209 Notch 210 Front Weight Assembly 212 Rear Weight Assembly 214 Front Weight Track 216 Rear Weight Track 224 Rear Seating Pad (Ground Contact Surface) 225 Overhang Lip 226 Front Seating Pad (Ground Contact Surface) 228 Overhang Lip 230 Toe Portion 232 Toe Side Cantilevered Ridge 234 Heel Side Cantilevered Ridge 236 Rib 238 Thick Region 240 Toe Side Opening 242 Heel Side Opening 244 Rear Track Opening 250 Ridge 252 Crown Region 260 Ridge 262, 263, 265, 267 Rib 270 Face 280, 286 Inner Concavity 282, 294 Concavity 284, 288 Peripheral Rail 290, 292 Peripheral Rail 296, 298 Inner Concavity 400 Club Head 402 Cup 404 Ring 406 Crown Insert 408 Sole Insert 410 Head - Shaft Connection Assembly 412 Hosel 418 Sole Slot 420 Junction 426 Crown Ridge 428 Sole Ridge 430 Protrusion 431 Rear Weight Port 432 Mass Pad 433 Weight Port 434 Integral Face 438 Sole Portion 450 Sleeve 452 Ferrule 454 Hosel Insert 456 Fastener 458 Washer 500 Wax Cup 502 Wax Cup Frame 504 Wax Face 506 Annular Joint 508 Wax Spring 510 Wax Cup 520 Additional Protrusion 600 Casting Cup 602 Center of Face 603 Inner Blend Area 604 Maximum Thickness Ring 606 Variable Blend Area 608 Second Ring 609 Outer Blend Area 610 Heel and Toe Area 612 Radial Peripheral Area 700 Casting Face Portion 702 Center of Face 703 Inner Blend Area 704 Maximum Thickness Ring 705 Variable Blend Area 706 Outer Area 708 Outer Blend Area 710 Peripheral Ring 800 Casting Face Portion 802 Center of Face 803 Inner Blend Area 804 Inner Ring 805 Second Blend Area 806 Second Ring 808 Third Ring 810 Fourth blend area 811 Fourth ring 812 Ear end area 813 Outer blend area 814 Outer peripheral part, peripheral ring 820 Thickening area 822 Offset area 823, 825 Ring 824, 826 Blend area 900 Cast face plate 902 Front part 904 Rear part B Golf ball X X-axis Y Y-axis Z Z-axis

Claims

1. 300cm 3 ~500cm 3 1. A driver-type golf club head having a volume, a first portion of the driver-type golf club head having a forward portion of the driver-type golf club head including a heel portion, a toe portion, a forward portion of a crown, and a forward portion of a sole, the first portion having a first material having a first material density; a rearward ring formed separately from the first portion and bonded to the first portion of the driver-type golf club head, the rearward ring connecting to the first portion such that a seam is formed between the rearward ring and the first portion to form a club head body defining a hollow interior region, a crown opening, and a sole opening, the rearward ring having a second material having a second material density; the first portion at least partially surrounds a forward portion of the crown opening and a forward portion of the sole opening, and the rear ring at least partially surrounds a rearward portion of the crown opening and a rearward portion of the sole opening; the forward portion of the crown opening is defined by a recessed ledge of a forward crown opening of the first portion, and the forward portion of the sole opening is defined by a recessed ledge of a forward sole opening of the first portion; a rearward ring, the rearward portion of the crown opening being defined by a recessed ledge of a rearward crown opening of the rearward ring and the rearward portion of the sole opening being defined by a recessed ledge of a rearward sole opening of the rearward ring; a crown insert surrounding the forward portion of the crown opening and the rearward portion of the crown opening and adhesively secured to a recessed ledge of the forward crown opening and a recessed ledge of the rearward crown opening, the crown insert being formed separately from the first portion and the rearward ring; A rear weight fixed to the rear ring; a sole insert surrounding the forward portion of the sole opening and the rearward portion of the sole opening and adhesively secured to a recessed ledge of the forward sole opening and a recessed ledge of the rearward sole opening, the sole insert being formed separately from the first portion, the rearward ring, and the crown insert; the first portion of the driver-type golf club head further comprises toe and heel male projections and the rear ring further comprises toe and heel female notches, the toe and heel male projections mating with corresponding ones of the toe and heel female notches to couple the first portion to the rear ring; or the first portion of the driver-type golf club head further comprising toe and heel female notches, and the rearward ring further comprising toe and heel male projections that mate with corresponding ones of the toe and heel female notches to couple the rearward ring to the first portion; A driver-type golf club head, wherein the rear ring forms a rear toe portion and a rear heel portion of the golf club head and defines a portion of the outermost circumference of the golf club head.

2. A lower portion of the recessed ledge of the forward sole opening extends rearwardly to a position rearward of an upper portion of the recessed ledge of the forward crown opening.

2. The driver-type golf club head according to claim 1.

3. At least a portion of the forward sole opening recessed ledge is located forward of at least a portion of the fastener port.

2. The driver-type golf club head according to claim 1.

4. At least a portion of the forward sole opening recessed ledge is located forward of at least a portion of the hosel.

2. The driver-type golf club head according to claim 1.

5. At least a portion of the recessed ledge of the front crown opening is located forward of at least a portion of the hosel.

2. The driver-type golf club head according to claim 1.

6. The first portion further includes a face portion, The face portion has a front surface and a back surface defining a variable face thickness profile between the front surface.

2. The driver-type golf club head according to claim 1.

7. The variable face thickness profile is offset toward a toe side of the face portion.

7. A driver-type golf club head according to claim 6.

8. The thickness of the center portion of the face portion is less than the maximum thickness of the face portion, and the face portion has a thickness variation of 25% across the face portion.

7. A driver-type golf club head according to claim 6.

9. The first material and the second material are different materials, and the density of the second material is less than the density of the first material.

2. The driver-type golf club head according to claim 1.

10. a front weight secured to the bottom of the first portion.

2. The driver-type golf club head according to claim 1.

11. the first portion of the driver-type golf club head further includes female notches at the toe and heel, and the rear ring further includes male protrusions at the toe and heel; The first portion is free of male protrusions on the forward portion of the crown.

2. The driver-type golf club head according to claim 1.

12. The sole opening has a single sole opening extending from a heel portion of the golf club head to a toe portion of the golf club head, and the sole insert has a single sole insert extending from the heel portion of the golf club head to the toe portion of the golf club head and surrounding the single sole opening.

2. The driver-type golf club head according to claim 1.

13. The front weight is fixed at a position in front of the rear weight and in the heel direction.

11. A driver-type golf club head according to claim 10.

14. 300cm 3 ~500cm 3 1. A driver-type golf club head having a volume, a first portion of the driver-type golf club head having a forward portion of the driver-type golf club head including a heel portion, a toe portion, a forward portion of a crown, and a forward portion of a sole, the first portion having a first material having a first material density; a rearward ring formed separately from the first portion and bonded to the first portion of the driver-type golf club head, the rearward ring connecting to the first portion such that a seam is formed between the rearward ring and the first portion to form a club head body defining a hollow interior region, the rearward ring having a second material having a second material density; a crown insert secured to and overlapping a first recessed ledge of the first portion of the driver-type golf club head to form a first overlap joint with the first portion of the driver-type golf club head and secured to and overlapping a second recessed ledge of the rear ring to form a second overlap joint with the rear ring, a portion of the crown insert not overlapping either the rear ring or the first portion of the driver-type golf club head; a sole insert secured to and overlapping a third recessed ledge of the first portion of the driver-type golf club head to form a third overlap joint with the first portion of the driver-type golf club head and secured to and overlapping a fourth recessed ledge of the rear ring to form a fourth overlap joint with the rear ring, a portion of the sole insert not overlapping either the rear ring or the first portion of the driver-type golf club head; a rear weight fixed to the rear ring; the first portion of the driver-type golf club head further comprises toe and heel male projections and the rear ring further comprises toe and heel female notches, the toe and heel male projections mating with corresponding ones of the toe and heel female notches to couple the first portion to the rear ring; or the first portion of the driver-type golf club head further comprising toe and heel female notches, and the rearward ring further comprising toe and heel male projections that mate with corresponding ones of the toe and heel female notches to couple the rearward ring to the first portion; A driver-type golf club head, wherein the rear ring forms a rear toe portion and a rear heel portion of the golf club head and defines a portion of the outermost circumference of the golf club head.

15. A lower portion of the first portion that forms the third overlap joint extends rearward to a position rearward of an upper portion of the first portion that forms the first overlap joint.

15. A driver-type golf club head according to claim 14.

16. At least a portion of the first portion forming the third overlap joint is located forward of at least a portion of the fastener port.

15. A driver-type golf club head according to claim 14.

17. At least a portion of the first portion that forms the third overlap joint is located forward of at least a portion of the hosel.

15. A driver-type golf club head according to claim 14.

18. At least a portion of the first portion that forms the first overlap joint is located forward of at least a portion of the hosel.

15. A driver-type golf club head according to claim 14.

19. The first portion further includes a face portion, The face portion has a front surface and a back surface defining a variable face thickness profile between the front surface.

15. A driver-type golf club head according to claim 14.

20. The variable face thickness profile is offset toward a toe side of the face portion.

20. A driver-type golf club head according to claim 19.

21. The thickness of the center portion of the face portion is less than the maximum thickness of the face portion, and the face portion has a thickness variation of 25% across the face portion.

20. A driver-type golf club head according to claim 19.

22. The first material and the second material are different materials, and the density of the second material is less than the density of the first material.

15. A driver-type golf club head according to claim 14.

23. a front weight secured to the bottom of the first portion.

15. A driver-type golf club head according to claim 14.

24. the first portion of the driver-type golf club head further includes female notches at the toe and heel, and the rear ring further includes male protrusions at the toe and heel; The first portion is free of male protrusions on the forward portion of the crown.

15. A driver-type golf club head according to claim 14.

25. a single sole opening extending from a heel portion of the golf club head to a toe portion of the golf club head, the sole insert having a single sole insert extending from the heel portion of the golf club head to the toe portion of the golf club head and surrounding the single sole opening; 15. A driver-type golf club head according to claim 14.

26. a front weight secured to a bottom of the first portion; The front weight is fixed at a position in front of the rear weight and in the heel direction.

15. A driver-type golf club head according to claim 14. At least a portion of the rear weight is secured to the rear ring rearward of the sole opening.

26. A driver-type golf club head according to claim 1 or 25.

28. The male protrusions on the toe and heel engage with corresponding female notches on the toe and heel at a first joint location and a second joint location.

15. A driver-type golf club head according to claim 1 or 14.

29. At least a portion of the first joint position and the second joint position are located rearward of a hosel axis of the golf club head.

29. A driver-type golf club head according to claim 28.

30. The first joining position is located closest to the toe of the toe portion of the golf club head.

30. A driver-type golf club head according to claim 29.

31. The first joint position and the second joint position are located 20 mm to 70 mm behind the center plane of the golf club head.

29. A driver-type golf club head according to claim 28.

32. At least a portion of at least one of the toe male protrusions and / or the heel male protrusions extends at least 30 mm rearward of a center plane of the golf club head.

32. A driver-type golf club head according to claim 31.

33. The first portion and the rear ring are not directly joined to other portions between the first joining position and the second joining position.

29. A driver-type golf club head according to claim 28.

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