Golf club head

Abstract

The invention relates to a golf club head. The casting cup may include a front portion of a golf club head, including a hosel, a face portion, and a front portion of a crown, a front portion of a sole, a front portion of a heel, and a front portion of a toe. The rear ring may be formed separately from the cast cup and coupled to the heel portion and the toe portion of the cast cup to form a metal club head body such that the club head body defines a hollow interior region, a crown opening, and a bottom opening. The casting cup and the back ring may be cast from a titanium alloy. Composite crown and bottom inserts may then be coupled to the crown and bottom openings. The face portion of the casting cup may have an ideally complex geometry. The rear surface of the face portion of the casting cup may be modified before the rear ring is attached.

Description

[0001] This application is a divisional application of the application filed on October 16, 2019, with application number 201910980883.X and invention title "Golf Club Head". Technical Field

[0002] This disclosure relates to golf club heads having cast components and related methods for manufacturing such golf club heads. Background Technology

[0003] With the increasing popularity and competitiveness of golf, significant effort and resources are being invested in improving golf clubs. Many recent improvements have involved combinations of new and increasingly sophisticated materials with advanced clubhead engineering. For example, modern "woods" (such as "drivers," "fairway woods," "rescues," and "multi-purpose or hybrid clubs") bear little resemblance to the "wooden" drivers, low-loft long-irons, and higher-numbered fairway woods used many years ago, due to their complex shafts and non-wooden clubheads. These modern woods are often referred to as "metal woods" or simply "woods."

[0004] The current ability to manufacture metal wood clubheads using strong, lightweight metals and other materials has allowed for hollow clubheads. The use of high-strength and high-fracture-toughness materials has also allowed for thinner clubhead walls, reducing overall weight compared to earlier clubheads and allowing for larger clubhead sizes without a swing speed penalty. Larger clubheads tend to have larger facet areas and can also be manufactured with higher clubhead inertia, making them more forgiving than smaller clubheads. Characteristics such as the size of the optimal impact point (also known as the "sweet spot") are determined by many variables, including the shape, profile, size, and thickness of the facet, as well as the location of the clubhead's center of gravity (CG).

[0005] Exemplary metal wood golf clubs typically include a shaft with a lower end to which the clubhead is attached. Most modern versions of these clubheads are at least partially made of a lightweight but strong metal such as titanium alloy. In some cases, the clubhead includes a body to which the faceplate (used interchangeably herein with the terms "face" or "face insert" or "striking plate" or "strike plate") is attached later, while in other cases, the body and faceplate are cast together as a single integral structure, so that the faceplate does not need to be attached later to the body. The faceplate defines the front surface, or striking face, that actually contacts the golf ball.

[0006] The total mass of a metal wood clubhead is considered its mass budget. At least a portion of this budget must be dedicated to providing sufficient strength and structural support for the clubhead. This is called "structural" mass. Any remaining mass in the budget is called "discretionary" or "performance" mass, which can be distributed within the metal wood clubhead to address, for example, performance issues. Therefore, the ability to reduce the structural mass of a metal wood clubhead without compromising strength and structural support offers the potential to increase discretionary mass, thereby improving club performance.

[0007] One opportunity to reduce the overall mass of a golf club head is to reduce the thickness of the face to decrease its mass; however, this opportunity is limited given the face's absorption of the initial impact of the ball and the rather stringent requirements placed on its physical and mechanical properties. Considering the lightweight and high strength of titanium and titanium alloys, club manufacturers have used them for face manufacturing as well as for the overall club head construction. Typically, for club heads, casting processes have been used in their manufacture due to their relatively complex 3D structure. Many such faces are manufactured using investment casting, where a suitable molten metal is cast into a preheated ceramic investment mold formed by a lost-wax process. Investment casting has also been used to prepare faces either as an integral structure cast together with the rest of the club head body, or as a separately formed face that is then typically attached to the front of the club head body by welding. Despite its widespread use, investment casting of complex shaped parts from such reactive materials is characterized by relatively high cost and low production volumes. Low casting yields can be attributed to several factors, including surface defects or void-type defects at the surface connections and / or inadequate filling of certain mold cavity areas, particularly thin mold cavity areas, as well as associated internal voids, shrinkage, and similar defects.

[0008] To further mitigate the defects of investment casting facets, clubhead manufacturers often introduce curvature into the face of the club to help compensate for directional issues caused by shots hit at locations other than the center of gravity. Therefore, in addition to a flat facet, manufacturers may want to create a facet with both heel-to-toe convex curvature (called a "bulge") and crown-to-bottom convex curvature (called a "roll"). Furthermore, manufacturers can introduce variable facet thickness profiles across the facet. Changing the facet thickness can increase the size of the COR zone, commonly known as the sweet spot of the clubhead, allowing a larger area of ​​the facet to consistently deliver high ball speed and forgiveness when the clubhead is struck. Moreover, changing the facet thickness can facilitate reducing the weight of the facet area for redistribution to other areas of the clubhead.

[0009] To compensate for the limitations of investment casting in creating these more complex panel structures, manufacturers have turned to alternative methods for forming the panels, including laser-cutting the panel shape from rolled titanium sheets, followed by forging to impart any desired bulges and protrusions, and then machining steps on a lathe to introduce any desired face thickness profile. The disadvantages of these steps include the fact that three separate forming steps are required, and the machining process for forming variable thickness profiles on a lathe is not only wasteful but also restricts the profile to a circular shape area due to the lathe's circular motion.

[0010] Therefore, it is highly desirable to allow for a reduction in the thickness of the clubhead face with sufficient physical properties to create more usable discretionary weight within the clubhead. It is also desirable that the face, in addition to exhibiting any variable thickness profile of any shape—circular, elliptical, asymmetrical, or other—can also possess any desired bulge curvature and hump curvature. It is also desirable to employ a simplified process for manufacturing such a face, producing a face with the desired thickness and physical strength properties, while also producing a face with any desired bulge and hump, as well as a variable thickness profile, requiring minimal processing steps and minimizing any waste generated in the process. It is also desirable that the clubhead body and face can be cast simultaneously from the same material as a single integral unit, rather than two parts that must be attached later. It is also desirable that the cast face does not require chemical etching to remove or reduce the thickness of the alpha case, thus providing sufficient durability properties for the face. Summary of the Invention

[0011] This article discloses several golf club head bodies that can be cast from 9-1-1 titanium, where the face, crown, sole, skirt, and sheath are cast together as a single, integral part of the body. Due to the 9-1-1 titanium material, the face and other parts of the body absorb less oxygen from the mold and can have a reduced alpha shell thickness, resulting in greater ductility and durability. This eliminates the need to reduce the alpha shell thickness after casting using hydrofluoric acid or other hazardous chemical etchants. Casting methods may include preheating the casting mold to below normal temperatures and / or coating the inner surface of the mold to further reduce the amount of oxygen transferred from the mold to the 9-1-1 titanium during casting.

[0012] In some embodiments, the body of a wood golf club head includes a crown, sole, skirt, face, and sheath; the body defines a hollow internal region; the body is substantially entirely cast from 9-1-1 titanium; and the body is cast as a single integral casting, wherein the face is integrally formed with the crown, sole, skirt, and sheath. The body may contain trace amounts of fluorine atoms as alloying impurities present in the titanium alloy, but the fluorine content in the body may be very low because there is no hydrofluoric acid etching of the face after casting. In some embodiments, the face 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 may have an α-shell thickness of 0.150 mm or less, 0.100 mm or less, and / or 0.070 mm or less.

[0013] Some exemplary methods include preparing a mold for casting, and then using the mold to cast the golf club head body substantially entirely of 9-1-1 titanium, wherein the cast body includes a crown, sole, skirt, face, and sheath, wherein the cast body defines a hollow internal region; and wherein the body is cast as a single integral casting, wherein the face is integrally formed with the crown, sole, skirt, and sheath during casting. Some such methods do not include etching the face after casting. In some methods, preparing the mold includes preheating the mold such that when casting occurs, the mold is at a temperature of 800°C or lower, 700°C or lower, 600°C or lower, and / or 500°C or lower.

[0014] This document also discloses embodiments of golf club heads, including a metallic cast cup forming the fore portion of the club head, the cast cup comprising an insert, a face portion, a fore portion of the crown, and a fore portion of the sole. A metallic rear ring may be formed separately from the cast cup and attached to the heel and toe portions of the cast cup to form the club head body, such that the metallic club head body defines a hollow internal region, a crown opening, and a sole opening. A composite crown insert may then be attached to the crown opening. A sole insert made of composite material, metal, or other material may be attached to the sole opening. In some embodiments, there is no sole opening or sole insert. The cast cup and rear ring may be cast from a titanium alloy and may be welded together to form the club head body. In some embodiments, the ring and cup comprise different metallic materials, such as two different titanium alloys or a titanium alloy and steel. The cast cup may include a face portion with a complex geometry to provide desired performance properties. The face portion may have a twisted front surface and / or the rear surface of the face may have a geometry that provides an asymmetrical, variable thickness profile across the face. The rear surface of the face portion of the cast cup may be machined and / or otherwise modified before the rear ring is attached, thereby increasing the space available for accessing the entire rear surface of the face using tools.

[0015] A method for forming a wax cup from a wax cup frame and a separately formed wax surface using a wax welding process is also disclosed. This wax cup can then be used to produce a mold for casting a metal cup that forms the front part of a golf club head. The two-piece wax welding process offers manufacturing advantages, prototyping advantages, and testing advantages.

[0016] Cast panels with novel geometries, such as cast panels containing titanium alloys, were also disclosed.

[0017] This article also discloses a method for manufacturing a golf club head, the method comprising: casting a cup made of titanium alloy and including the entire face portion of the golf club head, a front portion only of the crown portion of the golf club head, a front portion only of the bottom portion of the golf club head, a front portion only of the toe portion of the golf club head, a front portion only of the heel portion of the golf club head, and a sheath, such that an α-shell is formed on the rear surface of the face portion; and machining the rear surface of the face portion to remove at least a portion of the α-shell from the rear surface of the face portion.

[0018] In some embodiments, the method further includes: forming a ring separately from the step of casting the cup; and attaching the ring to the cup such that the ring defines the outermost perimeter of the rear portion of the golf club head; wherein the step of machining the rear surface of the face portion occurs prior to the step of attaching the ring to the cup.

[0019] In some implementations, the ring is formed of a metallic material different from that of the cup, which is made of titanium alloy.

[0020] In some embodiments, the method further includes: attaching a crown insert made of composite material to the front portion of the crown of a golf club head defined by a ring and a cup; and attaching a bottom insert made of composite material to the front portion of the bottom of the golf club head defined by a ring and a cup.

[0021] In some embodiments, at least a portion of the α-shell is removed from the rear surface of the face portion without chemically etching the rear surface of the face portion.

[0022] In some embodiments, the step of casting the cup results in the formation of an α-shell on the front surface of the facial portion opposite to the rear surface; and the method further includes machining the front surface of the facial portion to remove at least a portion of the α-shell from the front surface of the facial portion.

[0023] This document also discloses a golf club head, comprising: a cup having a single integral body, the cup being made of titanium alloy, and including the entire face portion of the golf club head, a front portion only of the crown of the golf club head, a front portion only of the bottom of the golf club head, a front portion only of the toe of the golf club head, a front portion only of the heel of the golf club head, and a sheath, wherein the rear surface of the face portion of the golf club head defined by the cup is a machined surface; a ring attached to the cup and defining the outermost perimeter of the rear portion of the golf club head; and a crown insert made of composite material and attached to the ring and the front portion of the crown of the golf club head defined by the cup.

[0024] In some implementations, the ring is made of a different metallic material than the cup, which is a titanium alloy.

[0025] In some embodiments, the cup also includes a flange formed in the front portion of the crown of the golf club head defined by the cup; and a crown insert is received on the flange such that the flange is positioned inside the crown insert.

[0026] In some embodiments, the golf club head also includes a bottom insert made of composite material and attached to the front portion of the bottom of the golf club head, which is defined by a ring and a cup.

[0027] This article also discloses a wood-type golf club head, comprising: a metal casting cup including a front portion of the club head, the front portion including a sheath, a face portion, a front portion of the crown, and a front portion of the bottom; a metal rear ring separately formed from the casting cup and connected to the heel and toe portions of the casting cup to form a club head body, the club head body defining a hollow internal region, a crown opening, and a bottom opening; and a crown insert connected to the crown opening.

[0028] In some implementations, the cast cup and rear ring are made of titanium alloy.

[0029] In some embodiments, the cast cup comprises a titanium alloy containing 6.75% to 9.75% aluminum and 0.75% to 3.25% molybdenum by weight.

[0030] In some implementations, the casting cup also includes a slot in the front portion of the bottom.

[0031] In some implementations, the rear ring is welded to the cast cup.

[0032] In some implementations, the rear ring forms the skirt portion of the clubhead, defining the outermost perimeter surrounding the rear of the clubhead.

[0033] In some implementations, the clubhead also includes a bottom insert that attaches to the bottom opening.

[0034] In some implementations, the striking surface of the face portion is distorted such that the upper toe portion of the striking surface is more open than the lower toe portion of the striking surface, and the lower heel portion of the striking surface is more closed than the upper heel portion of the striking surface.

[0035] In some implementations, the clubhead also includes an adjustable head-shaft connection assembly that is attached to a sheath.

[0036] In some implementations, the facial portion includes an asymmetrical, variable facial thickness profile.

[0037] In some implementations, the rear surface of the facial portion includes an asymmetrical surface pattern about the center point of the facial portion.

[0038] In some implementations, the surface pattern includes a variable thickness profile that is offset toward the toe side or heel side of the face portion.

[0039] This document also discloses a method comprising: casting a cup of metal material, the cast cup comprising a front portion of a golf club head, the front portion comprising a full face portion, a front portion of a crown, a front portion of a bottom, a heel portion, a toe portion, and an insert; attaching a metal rear ring to the heel and toe portions of the cast cup to form a metal club head body, the rear ring forming a rear skirt of the club head body, the club head body defining a hollow internal region, a crown opening, and a bottom opening; attaching a composite material crown insert to the crown opening; and attaching a composite material bottom insert to the bottom opening.

[0040] In some implementations, the cup and rear ring are cast from titanium alloy.

[0041] In some implementations, the method further includes casting the rear ring of metallic material before attaching it to the casting cup.

[0042] In some embodiments, attaching the rear ring to the casting cup includes welding the front end of the rear ring to the toe and heel portions of the casting cup.

[0043] In some embodiments, the method further includes machining the rear surface of the face portion of the casting cup before attaching the rear ring to the casting cup.

[0044] In some embodiments, the method further includes removing part or all of the α-shell from the face portion after the cup is cast and before the rear ring is attached to the cast cup.

[0045] This article also discloses a method for forming a wax cup, comprising: forming a wax cup frame including a front crown portion, a front bottom portion, a toe portion, a heel portion, a sheath portion, and a face opening; forming a wax surface; inserting the wax surface into the face opening of the wax cup frame; and welding the wax surface around a joint wax to the wax cup frame, wherein at the joint, the outer periphery of the wax surface is adjacent to the inner periphery of the face opening, thereby forming a wax cup suitable for manufacturing a mold for casting a metal cup for a golf club head.

[0046] In some embodiments, the method further includes: forming a mold around the wax cup; and casting a titanium alloy cup in the mold, the cast cup including a front portion of a golf club head, the front portion including a full face portion, a front portion of the crown, a front portion of the base, a heel portion, a toe portion, and a sheath.

[0047] In some embodiments, the face has a thickness of no more than 6 mm within a 5 mm radius of the geometric center of the face portion, and an α shell thickness of no more than 0.30 mm exists on the inner surface of the face portion.

[0048] The foregoing contents and other objectives, features and advantages of the disclosed technology will become more apparent from the following detailed description with reference to the accompanying drawings. Attached Figure Description

[0049] Figure 1 This is a side view of a golf club head.

[0050] Figure 2 yes Figure 1 A front view of a golf club head.

[0051] Figure 3 yes Figure 1 A bottom perspective view of a golf club head.

[0052] Figure 4 This shows the original coordinate system of the golf club head. Figure 1 A front view of a golf club head.

[0053] Figure 5 It shows the centroid coordinate system. Figure 1 A side view of a golf club head.

[0054] Figure 6 yes Figure 1 A top-down view of a golf club head.

[0055] Figure 7 This is a rear view of an exemplary panel with variable thickness.

[0056] Figure 8 It is along Figure 7 The line 8-8 cut Figure 7 A cross-sectional view of the panel.

[0057] Figure 9 It is along Figure 7 The line 9-9 was cut off Figure 7 A cross-sectional view of the panel.

[0058] Figure 10 This is a front view of the golf club head of the present invention, which shows the bulge and rise measurement system.

[0059] Figure 11 This is an illustration of a golf club head that strikes the golf ball from the heelward side.

[0060] Figure 12 This is a top view of an exemplary initial pattern of a wood club head, showing the main gate, assistant gate, and flow channel.

[0061] Figure 13 It is a schematic depiction of a casting cluster that includes multiple mold cavities.

[0062] Figure 14 It is a schematic depiction of another casting module that includes multiple mold cavities.

[0063] Figure 15 This is a flowchart illustrating the process used to cast golf club heads.

[0064] Figure 16 It is a table of casting data for titanium alloys obtained from six different casting machines.

[0065] Figure 17 yes Figure 16 The continuation of the table.

[0066] Figure 18 This is a graph showing the consumption of pouring material (molten metal) for titanium alloys relative to mass, with mass indicating the size of the casting furnace for various casting machines.

[0067] Figure 19 This is a flowchart of an implementation scheme for configuring a casting module.

[0068] Figure 20 This is yet another exemplary bottom perspective view of a golf club head disclosed in this article.

[0069] Figure 21 yes Figure 20 A bottom perspective view of the disassembled golf club head.

[0070] Figure 21A yes Figure 20 A side perspective view of the disassembled golf club head.

[0071] Figure 22 yes Figure 20 A top view of the main body of a golf club head.

[0072] Figure 23 It is along Figure 22 The cross-sectional view of the main body is taken by line 23-23 in the figure.

[0073] Figure 24 yes Figure 20 A bottom view of a golf club head.

[0074] Figure 25 It is along Figure 24 The cross-sectional view taken from line 25-25 in the figure.

[0075] Figure 26 yes Figure 20 A side view of the heel of a golf club head.

[0076] Figure 26A yes Figure 20 A side view of the toe section of a golf club head.

[0077] Figure 27 yes Figure 22 A top-view cross-section of the lower part of the main body.

[0078] Figure 28 yes Figure 22 A cross-sectional side view of the toe portion of the main body.

[0079] Figure 29 yes Figure 22 A bottom view of the front part of the bottom of the main body.

[0080] Figure 30 It is roughly along Figure 29 A magnified, detailed cross-sectional view of the side-to-side weighttrack, taken from line 30-30.

[0081] Figure 31 It is roughly along Figure 29 Another enlarged detailed cross-sectional view of the side-to-side counterweight track, taken from line 31-31.

[0082] Figure 32 It includes the front-to-rear counterweight track. Figure 22 A bottom view of part of the bottom of the main body.

[0083] Figure 33 It is roughly along Figure 32 A magnified detailed cross-sectional view of the front to rear counterweight track, taken from line 33-33.

[0084] Figure 34 It is roughly along Figure 32 Another enlarged detailed cross-sectional view of the front to rear counterweight track, taken from line 34-34.

[0085] Figure 35A The crown portion was removed. Figure 20 A top view of a golf club head, showing the bottom portion positioned within the body.

[0086] Figure 35B yes Figure 20 A top view of the bottom part of a golf club head.

[0087] Figure 35C It is the crown portion in the appropriate position. Figure 20A top view of a golf club head.

[0088] Figure 35D Both the crown and the base were removed. Figure 20 A top view of a golf club head.

[0089] Figure 36A yes Figure 20 A front view of the bottom portion of a golf club head.

[0090] Figure 36B yes Figure 20 A bottom view of the bottom part of a golf club head.

[0091] Figure 36C yes Figure 20 A side view of the crown portion of a golf club head.

[0092] Figure 36D yes Figure 20 A top view of the crown portion of a golf club head.

[0093] Figure 37 This is a perspective view of another exemplary golf club head.

[0094] Figure 38 It has a clubhead-shaft connection assembly. Figure 37 Different perspective views of the clubhead.

[0095] Figure 39 Show Figure 37 How the main body of a golf club head is formed by two parts attached together.

[0096] Figure 40 Showing the assembly state Figure 39 The main body.

[0097] Figure 41 Show how the crown insert and bottom insert work together Figure 40 The main body is assembled together.

[0098] Figure 42 Showing the front of the cup-shaped part of the main body.

[0099] Figure 43 Showing the back of the cup surface portion of the main body.

[0100] Figure 44 This is the front view of the main body.

[0101] Figure 45 This is a side view of the base of the main body.

[0102] Figure 46 It is a top-down plan view of the main body.

[0103] Figure 47 It is a bottom view of the main body.

[0104] Figure 48 This is a cross-sectional view of the clubhead-shaft connection assembly.

[0105] Figure 49 The illustration shows a two-piece wax body, which has a wax surface formed separately from the rest of the wax body.

[0106] Figure 50 The wax surface is shown as the wax is welded to the rest of the wax body.

[0107] Figure 51 The different thickness contours on the back of the face are shown.

[0108] Figure 52 This shows another different thickness profile on the back side of the face.

[0109] Figure 53 yes Figure 52 A perspective view of the face.

[0110] Figure 54 This shows another different thickness profile that is offset towards the heel side.

[0111] Figure 55 The front side of an exemplary cast panel is shown.

[0112] Figure 56 Show Figure 55 The back side of the cast panel. Detailed Implementation

[0113] The following describes an implementation scheme for the clubhead of a metal wood golf club, which includes drivers, fairway woods, hybrids, multi-purpose clubs, hybrid clubs, and similar clubs.

[0114] The inventive features disclosed herein include all novel and non-obvious features disclosed individually, as well as combinations with any other features. As used herein, the phrase “and / or” means “and,” “or,” and both “and” and “or.” As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” refer to one or more. As used herein, the term “includes” means “comprises.”

[0115] The following description also refers to the accompanying drawings, which form part of this document. The drawings illustrate specific embodiments, but other embodiments may be formed and structural changes may be made without departing from the intended scope of this disclosure. Orientations and references (e.g., upper, lower, top, bottom, left, right, rear, front, heel, toe, etc.) may be used to facilitate the discussion of the drawings, but are not intended to be limiting. For example, certain terms such as “upper,” “lower,” “upper part,” “lower part,” “horizontal,” “vertical,” “left,” “right,” etc., may be used. These terms are used where applicable to provide some clarity of description, especially relative to the illustrated embodiments, when dealing with relative relationships. However, such terms are not intended to imply absolute relationships, positions, and / or orientations. For example, with respect to an object, an “upper” surface can simply be transformed into a “lower” surface by flipping the object. However, it remains the same object. Therefore, the following detailed description should not be interpreted in a limiting sense, and the scope of the sought property should be defined by the appended claims and their equivalents.

[0116] Unless otherwise specifically stated, conditional terms such as “can,” “may,” “may,” or “can,” or other terms understood in the context in which they are used, are generally intended to express that certain embodiments include certain features, elements, and / or steps while other embodiments do not. Therefore, such conditional terms are generally not intended to imply that features, elements, and / or steps are required in any way for one or more particular embodiments, or that one or more particular embodiments necessarily include logic for determining whether or not such features, elements, and / or steps are included in any particular embodiment or whether or not they are performed in any particular embodiment.

[0117] It should be emphasized that the embodiments described herein are merely possible examples of implementation methods, and are only illustrated for the purpose of clearly understanding the principles of this disclosure. Any process description or block in the flowcharts should be understood as representing a module, segment, or code portion containing one or more executable instructions for implementing a specific logical function or step in the process, and includes alternative implementations in which the function may not be included or performed at all, may not be performed in the order shown or discussed, including substantially simultaneously or in reverse order, depending on the function involved, as will be reasonably understood by those skilled in the art. Many variations and modifications can be made to the embodiments described above without substantially departing from the spirit and principles of this disclosure. Furthermore, the scope of this disclosure is intended to cover any and all combinations and sub-combinations of all elements, features, and aspects discussed above. All such modifications and variations are intended to be included within the scope of this disclosure, and all possible claims for a combination of aspects or elements or steps are intended to be supported by this disclosure.

[0118] For reference, within this disclosure, the term "driver golf club head" refers to any metal wood golf club head intended primarily for use with a tee. Driver golf club heads typically have a face loft of 15 degrees or less, and more commonly 12 degrees or less. The term "fairway wood golf club head" refers to any wood golf club head intended for striking the ball off the ground, but which can also be used to strike the ball off the tee. Fairway wood golf club heads typically have a face loft of 15 degrees or greater, and more commonly 16 degrees or greater. Fairway wood golf club heads typically have a length from the leading edge to the trailing edge of 73-97 mm. Various definitions distinguish fairway wood golf club heads from hybrid golf club heads, which tend to resemble fairway wood golf club heads but have a shorter length from the leading edge to the trailing edge. Typically, the length of a hybrid golf club head from its leading edge to its trailing edge is 38-73mm. Hybrid golf club heads can also be distinguished from fairway wood golf club heads by weight, lie angle, volume, and / or shaft length. Currently disclosed driver golf club heads can be 15 degrees or less in various embodiments, or 10.5 degrees or less in various embodiments. In various embodiments, currently disclosed fairway wood golf club heads can be 13-26 degrees.

[0119] like Figure 1-6 As illustrated in the diagram, a golf club head, such as a golf club head 2, can include a hollow body 10. The body 10 can include a crown 12, a base 14, a skirt 16, and a face 18 (also referred to as the face or face portion) that define a striking surface 22 and an internal cavity. The face 18 can be formed separately from the body and attached to an opening at the front of the body, or it can be integrally formed as a single part of the body 10. The body 10 can include a sheath 20 that defines a sheath hole 24 adapted to receive the golf club shaft (see [reference]). Figure 6 The main body 10 also includes a heel portion 26, a toe portion 28, a front portion 30, and a rear portion 32.

[0120] Figure 4-6 The diagram illustrates the ideal impact position / origin 23, 60, original x-axis 70, original y-axis 75, and original z-axis 65, clubhead center of gravity 50, CG x-axis 90, CG y-axis 95, and CG z-axis 85. When the clubhead is in the normal address position, these axes are horizontal or vertical, as shown. The original axes pass through the origin 60, and the CG axis passes through CG50.

[0121] The body may also include openings in the crown and / or sole, which are overlapped or covered by inserts made of lightweight materials such as composites. For example, the crown of the body may include a composite crown insert that covers a large area of ​​the crown and has a lower density than the metal used to make the body, thus saving weight in the crown. Similarly, the sole may include one or more openings in the body covered by a sole insert. The sole insert may be made of composite materials, metal, or other materials. In embodiments where the body includes openings in the crown or sole, such openings provide access to the internal cavity of the clubhead during manufacturing, especially where the face is formed as a single piece of the body during casting (and there are no face openings in the body that provide access during manufacturing). Figure 20-3 The clubhead disclosed herein provides examples of openings in the crown and sole that are overlapped or covered by inserts formed of a lighter material, such as composite materials. Further information regarding the openings in the body and the associated inserts can be found in U.S. Patent Publication 2018 / 0185719, published July 5, 2018, and U.S. Provisional Application No. 62 / 515,401, filed June 5, 2017, both of which are incorporated herein by reference in their entirety.

[0122] In some embodiments, the clubhead may include adjustable weights, such as one or more weights movable along weight tracks formed in the bottom and / or perimeter of the clubhead. Other exemplary weights can be adjusted by rotating weights within a threaded weight port. Various ribs, struts, mass pads, and other structures may be included within the body to provide reinforcement, adjust mass distribution and MOI properties, adjust acoustic properties, and / or for other reasons.

[0123] Wood club heads, such as clubhead 2, typically have cubic centimeters (cm). 3 The volume measured is equal to the volumetric displacement of the clubhead, assuming any holes are sealed by a generally flat surface. (See the USGA's "Procedure for Measuring the Club Head Size of WoodClubs," version 1.0, November 21, 2003). In the case of a driver, the golf clubhead can have a volume of approximately 250 cm. 3 and approximately 600 cm 3Between, such as at approximately 300 cm 3 and about 500cm 3 The volume is between approximately 145 g and approximately 260 g. In the case of fairway woods, the golf club head can have a volume between approximately 120 cm. 3 and about 300 cm 3 The volume can be between approximately 115g and approximately 260g. In the case of multi-purpose or hybrid clubs, the golf club head can have a volume between approximately 80cm. 3 and approximately 140 cm 3 The volume is between approximately 105 g and approximately 280 g, and the total mass can be between approximately 105 g and approximately 280 g.

[0124] The sole 14 is defined as the lower portion of the clubhead 2, extending upward from the lowest point of the clubhead when the clubhead is ideally positioned, i.e., at a suitable address position relative to the golf ball on a horizontal surface. In some embodiments, the sole 14 extends approximately 50% to 60% of the distance from the lowest point of the clubhead towards the crown 12; in some cases, this distance may be approximately 15 mm for drivers and between approximately 10 mm and 12 mm for fairway woods.

[0125] Materials that can be used to construct the body 10, including panel 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 paint, polymer materials, ceramic materials, etc., may also be included in the body. In some embodiments, the body of the panel may be made of a metallic material such as 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 α / near-α titanium alloys, α-β titanium alloys and β / near-β 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 and 7000 series alloys such as 7075); or Ti Grade9 (Ti-3Al-2.5V) having a chemical composition of ≤3.5-2.5% Al, ≤3.0-2.0% V, ≤0.02% N, ≤0.013% H, and ≤0.12% Fe.

[0126] Aspects of investment casting Injection molding is used to form a sacrificial "initial" prototype (e.g., made from casting "wax") for the desired casting. A suitable injection mold can be made from aluminum or other suitable metals or metal alloys, or other materials, for example, using a casting master through computer-controlled machining processes. CNC (Computer Numerical Control) machining can be used to create the complexity of the mold cavity within the mold. The cavity dimensions are established to compensate for the linear and volumetric shrinkage of the casting wax encountered during the casting of the initial prototype, and also to compensate for any similar shrinkage anticipated during the actual metal casting, which is performed later using an investment casting "shell" formed from the initial prototype.

[0127] Typically, a set of initial samples are assembled together and attached to a central wax sprue to form a casting "module". Each initial sample in the module forms a corresponding mold cavity in the casting shell that is later formed around the module. The central wax sprue defines the location and configuration of the runner channels and gates used to deliver the molten metal introduced into the sprue along a predetermined path to the mold cavity in the casting shell. The runner channels may include one or more filters (e.g., made of ceramic) to enhance the smooth laminar flow of the molten metal into and within the casting shell, and to prevent any scum that may be trapped in the mold from entering the shell cavity.

[0128] The investment casting shell is constructed by immersing a casting mold in a liquid ceramic slurry, followed by immersion in a bed of refractory particles. This immersion sequence is repeated as needed to establish a sufficient wall thickness of ceramic material around the casting mold, thereby forming the investment casting shell. An exemplary immersion sequence includes six immersions of the casting mold in the liquid ceramic slurry and five immersions in the bed of refractory particles, producing an investment casting shell comprising alternating layers of ceramic slurry and refractory material. The first two layers of refractory material desirably contain fine (300 mesh) zirconia particles, and the third to fifth layers of refractory material may contain coarser (200 to 35 mesh) alumina particles. Each layer is dried at a controlled temperature (25 ± 5 °C) and relative humidity (50 ± 5%) before the next layer is applied.

[0129] The investment casting mold shell is placed inside, and the pressure is rapidly increased to 7-10 kg / cm². 2 The shell is placed in a sealed, high-pressure steam autoclave. Under these conditions, the wax in the shell is melted using injected steam. The shell is then baked in an oven where the temperature is gradually increased to 1000-1300°C to remove residual wax and increase the shell's strength. The shell is now ready for investment casting.

[0130] After the clubhead is designed and initial prototypes are made, manufacturing is transferred to a metal casting machine. To create the investment casting shell, the metal casting machine first configures a module containing multiple initial prototypes for each individual clubhead. Configuring the module also involves configuring the metal delivery system (with gates and runners for later delivery of molten metal). After these tasks are completed, the casting machine begins manufacturing the casting shell using tools.

[0131] A key aspect of configuring the mold is determining the placement of the gates. Mold cavities for individual golf club heads typically have a main gate through which molten metal flows into the mold cavity. Additional auxiliary (“auxiliary”) gates can be connected to the main gate via flow channels. During investment casting using this type of shell, molten metal flows through the respective main gate, through the flow channels, and through the auxiliary gates into each mold cavity. This flow pattern requires that the mold used to form the initial wax model of the golf club head also define the main gate and any auxiliary gates. After molding the initial wax model of the golf club head, the model is removed from the mold, and the location of the flow channels is defined by “gluing” the wax model between the gates (using the same wax). Reference Figure 12 , Figure 12 An initial prototype 150 of a metal wood golf club head is depicted. The main gate 152 and three auxiliary gates 154 are shown. A flow channel 156 interconnects the auxiliary gates 154 and the main gate 152.

[0132] The initial prototypes of the corresponding clubheads are then assembled into a module, which involves attaching individual master gates to a "ligament." The ligament comprises the module's runner and runner system. A "receptor," typically made of graphite or the like, is placed at the center of the module, where it will later be used to receive molten metal and guide it into the runner. The receptor desirably has a "funnel" configuration to facilitate the entry-flow of the molten metal. Additional supports (made of, for example, graphite) can be added to reinforce the module structure.

[0133] Typically, the entire wax mold is large enough (especially if the furnace chamber to be used to form the shell is large) to allow the wax pieces to be first “glued” to the individual branches of the mold, followed by individual ceramic coating of each branch before they are assembled together into the mold. Then, after the branches are assembled together, the mold is transferred to the shell casting chamber.

[0134] The two exemplary modules are respectively in Figure 13 and Figure 14 As shown in [the image]. Figure 13The depicted module 160 includes a graphite receiving section 162, graphite cross-spokes 164, a flow channel 166, and a mold cavity 168. Each mold cavity 168 is for a corresponding clubhead. Molten metal from the crucible 170 is poured into the module 160 using a pouring cup 172, which guides the molten metal into the receiving section 162, into the branch 166, and then into the mold cavity 168. Figure 14 The module 180 depicted includes a receiving portion 182 connected to a shell runner 184. The mold cavities in this configuration have two types: a "straight feed" cavity 186 and a "side feed" cavity 188. Molten metal from a crucible 170 is poured into the module 180 using a pouring cup 172, which guides the molten metal into the receiving portion 182, into the shell runner 184, and then into the mold cavities 186 and 188.

[0135] The reinforced wax mold is then coated with multiple layers of slurry and ceramic powder, with drying occurring between the layers. After all layers are formed, the resulting investment casting shell is steam-pressed to melt the wax inside (the ceramic and graphite portions do not melt). After the wax is removed from the shell, it is sintered (fired), which substantially increases its mechanical strength. If the shell will be used in a relatively small metal casting furnace (e.g., capable of accommodating a single-branch mold), it can now be used for investment casting. If the shell will be used in a relatively large metal casting furnace, it can be assembled with other shell branches to form a large, multi-branch mold.

[0136] Modern investment casting of metal alloys typically involves simultaneously rotating the casting mold shell centrifugally to harness and exploit the ω-axis of the shell undergoing this motion. 2 The force generated by the acceleration r, where ω is the angular velocity of the shell and r is the radius of the angular motion. This rotation is carried out under sub-atmospheric pressure using a turntable located inside the casting chamber. The force is generated by the ω of the shell. 2The force generated by the acceleration (r) drives the molten metal to flow into the mold cavity without leaving any voids. The investment casting shell (including its constituent modules and runners) is typically assembled outside the casting chamber and heated to a preset temperature before being placed as a single unit on a turntable within the chamber. After the shell is mounted onto the turntable, the casting chamber is sealed and evacuated to a preset subatmospheric pressure (“vacuum”) level. As the chamber is evacuated, the molten alloy prepared 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 rotates at the desired angular velocity. Thus, the molten metal is poured into the receiving portion of the casting shell and flows throughout the shell to fill the mold cavity within it.

[0137] As molten metal flows into the mold cavity and contacts its surface, the high-temperature environment (from both the molten metal and the preheated mold) promotes the diffusion of elements such as oxygen within the mold material. Although titanium casting is always carried out under sub-atmospheric pressure (vacuum) and oxygen is not readily available in the surrounding environment, it can still be found in the mold (because the mold is composed of multiple layers of "oxides"). Introducing oxygen into the molten titanium causes the formation of an oxygen-rich layer, the α-shell, on the surface of the titanium object to be cast. Typically, the thickness of the α-shell is approximately 1–4% of the object's thickness.

[0138] Because the alpha shell is rich in oxygen, it is brittle (oxygen is one of the most effective elements for increasing the strength of titanium alloys, but while increasing strength, ductility is greatly reduced), and it may easily crack under load. To reduce the tendency to form an alpha shell, the oxygen diffusion rate needs to be reduced, and to reduce the diffusion rate, the temperature needs to be lowered. However, lowering the temperature of molten titanium is not feasible. Therefore, lowering the temperature of the preheated shell is one way to reduce the oxygen diffusion rate, thereby reducing the formation of the alpha shell.

[0139] Typically, the casting shell is heated (called preheating) before being transferred to the casting furnace to facilitate the flow of molten titanium. The higher the preheating temperature of the shell, the easier the titanium flows. This is essential for thin-walled titanium casting, and preheating temperatures can reach as high as 1100-1200°C. On the other hand, such high temperatures tend to produce a thick α-shell layer (towards the higher end of the 1-4% wall thickness range). Therefore, if α-shell formation is a concern, the preheating temperature of the casting shell can be reduced. Typically, for non-flow critical titanium casting (where α-shell formation is undesirable), the preheating temperature of the casting shell is below 1000°C, or preferably below 900°C.

[0140] Module casting method For reference Figure 15As seen, the method for manufacturing a golf club head involves preparing a module as disclosed elsewhere in this disclosure, as shown with reference to step 361. In various embodiments, the module preparation step may include a preheating step as disclosed elsewhere herein. One aspect of the present disclosure is that the module preheating can be lower than that required by conventional investment casting techniques. For example, using conventional investment casting techniques, preheating can be approximately 1000°C–1400°C; using the centrifugal casting currently disclosed, the preheating temperature can be below 1000°C in some embodiments; below 800°C in some embodiments; or about 500°C or lower in some embodiments. In some embodiments, preheating is not required, and casting can occur at room temperature using a mold shell. When the module is prepared, it can be accelerated angularly according to step 362. The metal can be heated to a molten state simultaneously with module preparation and / or module acceleration, or this can be an intermediate step. However, the metal can be heated to a molten state according to step 363. The molten metal is introduced into the module according to step 364. As indicated by the dashed line leading from step 362 to step 364, the module may undergo angular acceleration before, after, or simultaneously with the introduction of molten metal into the module. The molten metal is allowed to cool according to step 365. The module casting is removed from the module shell in step 366, and post-processing occurs according to step 367 and subsequent steps.

[0141] 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 module to a certain angular velocity, for example, approximately 360 revolutions per minute. In various embodiments, the angular velocity can range from 250 to 450 revolutions per minute. In various embodiments, angular velocities as low as 150 rpm and as high as 600 rpm may be suitable.

[0142] The lower casting temperature allows for cooling of the molten metal within the mold module, resulting in reduced waiting time compared to conventional investment casting processes. This leads to improved throughput and better cycle times. In various gravity-dependent conventional investment casting methods, casting a maximum of only 6-8 parts is possible. Using centrifugal casting, 18-25 or more parts can be cast in a single cycle, increasing the production capacity per casting cycle. Furthermore, the output per gram of pour is increased. In conventional investment casting methods, a given mass of metal is used to cast a given number of golf club heads. Using the currently disclosed rotary casting technology, the same mass of metal can be used to produce more golf club heads. Improvements and advancements in the technology disclosed herein can further reduce this metal mass / head ratio. Depending on the specific methodology, reduced cycle times are also possible. Furthermore, the method described herein results in reduced tooling and capital expenditures required for the same production needs. Therefore, the method described herein reduces costs and improves product quality.

[0143] Furthermore, casting according to the method described herein results in material savings and enables higher production volumes because, given the increased acceleration and the resulting forces applied to the casting, the material can flow more easily to a greater number of clubheads. Finally, alloys typically manufactured using other methods can be more easily cast into similar geometries.

[0144] Gating configuration and module configuration Configuring the gating system and modules involves consideration of a number of factors. These include (but are not limited to): (a) the size limitations of the casting chamber of the metal casting furnace; (b) the processing requirements, particularly during the slurry impregnation step of forming the investment casting shell; (c) achieving the optimal flow pattern of the molten metal in the investment casting shell; (d) setting the modules of the investment casting shell to have at least the minimum strength required to withstand rotational motion during metal casting; (e) achieving a balance between minimizing resistance to the flow of molten metal into the mold cavity (by setting the runners to have a sufficiently large cross-section) and minimizing metal waste (e.g., by setting the runners to have a small cross-section); and (f) achieving mechanical balance of the modules around the central axis of the casting shell. Item (e) can be important because any metal remaining in the runners after casting does not form a product but may be “contaminated” (a portion of which is typically recycled). These configuration factors are combined with metal casting parameters such as the temperature and time of shell preheating, the vacuum level in the metal casting chamber, and the angular velocity of the turntable to produce the actual casting results. As clubhead walls are manufactured to be thinner and thinner, careful selection and balancing of these parameters are essential to producing appropriate investment casting results.

[0145] Details in investment casting, such as those performed on metal casting machines, tend to be proprietary. However, experiments on various titanium casting machines have revealed some consistency and general trends in the past. For example, specific golf club heads (with a diameter of 460 cm) exhibit specific characteristics. 3 The volume, crown thickness of 0.6 mm, and bottom thickness of 0.8 mm are manufactured at each of six titanium casting machines (with corresponding metal casting furnaces ranging from 10 kg to 80 kg capacity), producing the following: Figure 16 and Figure 17 The data in the middle. Figure 16 and 17 The parameters listed include the following: “R 最大值 " is the maximum radius of the module" “R 最小值 " is the minimum radius of the module" "Wet perimeter" is the total perimeter of the flow channel. "R (flow radius)" is the cross-sectional area of ​​the flow channel / wetted perimeter. A "sharp turn" is a turn of 90 degrees or more in a flow channel system. "Consumable consumption rate" is the ratio of consumption to the amount of material poured. "speed 最大值 "is the velocity at the maximum radius" "speed 最小值 "is the velocity at the minimum radius" "acceleration" 最大值 "is the acceleration at the maximum radius" "acceleration" 最小值 "is the acceleration at the minimum radius" "force 最大值 "This is the force at the maximum radius (note that this is an approximation of the force applied to the molten metal at the gate. Due to the specific design of each module, the actual force is almost always lower than the calculated value, with more complex modules exhibiting a greater force reduction.)" "force 最小值 "This is the force at the minimum radius (note that this is an approximation of the force applied to the molten metal at the gate. Due to the specific design of each module, the actual force is almost always lower than the calculated value, with more complex modules exhibiting a greater force reduction.)" "pressure 最大值 "This is the pressure (= force) of the molten metal in the flow channel at its maximum radius." 最大值 / Cross-sectional area of ​​the flow channel) "pressure 最小值 "This is the pressure (= force) of the molten metal in the flow channel at the minimum radius." 最小值 / Cross-sectional area of ​​the flow channel) "kinetic energy 最大值"It is the kinetic energy of the molten metal at its maximum radius." "Density" refers to the density of molten metal (titanium alloy) at its melting point of 1650°C. "Viscosity" refers to the viscosity of molten titanium at 1650°C. "Re number 最大值 "is the Reynolds number of the pipe flow rate at the maximum radius" "Re number 最小值 "and Re number" 最大值 It is consistently defined, but at the minimum radius.

[0146] Minimum force requirement Figure 16 and Figure 17 The following data table indicates that, for each module, at least a minimum force (and thus at least a minimum pressure) should be applied to the molten metal entering the casting mold shell to achieve good casting yield. The force applied to the molten metal is generated in part by the actual mass of the molten metal entering the mold cavity in the module and by the centrifugal force generated by the rotating turntable of the casting furnace. A reduced minimum force is desirable because a smaller force generally allows for a reduction in the amount of molten metal required per clubhead for casting. However, other factors tend to indicate an increase in this force, including: thinner wall sections in the article being cast, more complex modules (and therefore more complex flow patterns of the molten metal), lower mold shell preheating temperatures (resulting in greater heat loss from the molten metal as it flows into the investment casting mold shell), and substandard mold shell quality such as rough mold cavity walls. Figure 16 and Figure 17 The data indicates that the minimum force required to cast a titanium alloy clubhead is approximately 160 N, and at least a portion of the wall of the titanium alloy clubhead must be 0.6 mm thick. Casting machine 1 achieves this minimum force.

[0147] From the minimum force requirement, a lower threshold threshold for the amount of molten metal required to be poured into the shell can be derived. Excluding unavoidable pouring losses, the optimal metal content (as achieved by casting machine 1) for a club head, each with a mass of approximately 200 g (including the gate and some runners), is 386 g (0.386 kg). This is equivalent to a material utilization rate of 200 / 386 = 52%. The accelerations (maximum values) applied to the investment casting shell by casting machines 2-6 are all higher than those applied by casting machine 1, but each of casting machines 2-6 requires more molten metal to produce a corresponding casting output equivalent to that achieved by casting machine 1.

[0148] Some losses (splattering, cooling metal adhering to the crucible sidewalls and overflowing the supply of liquid titanium alloy, recovery cleaning losses, etc.) are unavoidable. These losses impose an upper limit on the efficiency achievable with a smaller casting furnace, i.e., such as... Figure 18 As shown in the figure, the percentage of energy consumption increases rapidly as the furnace size decreases.

[0149] On the other hand, smaller foundry furnaces advantageously have simpler operating and maintenance requirements. Other advantages of smaller furnaces are: (a) they tend to process smaller and simpler mold cavities; (b) smaller mold cavities tend to have separate corresponding runners for each mold cavity, which provides a better interface-gating ratio for the molten metal entering the mold cavity; (c) the furnace is easier and faster to preheat before casting; (d) the furnace offers potentially higher achievable shell preheating temperatures; and (e) smaller mold cavities tend to have shorter runners, which have lower Reynolds numbers and thus a reduced likelihood of destructive turbulence. While larger foundry furnaces do not tend to have these advantages, smaller foundry furnaces tend to have more unavoidable losses of molten metal per mold cavity compared to larger furnaces.

[0150] Given the above, a cost-effective casting system (furnace, module, output, net material cost) appears to encompass a medium-sized system, provided that appropriate module and gate design considerations are incorporated into the configuration of the investment casting shell used in such a furnace. This can be seen by comparing casting machines 1, 4, and 5. With these three casting machines, the total material consumption (without considering manufacturing costs) is very close (664-667 g / cavity). With casting machine 1, the material consumption (considering manufacturing costs) is 386 g, while the material consumption of casting machines 4 and 5 is 510 g. Therefore, while casting machines 4 and 5 can still be improved, it appears that casting machine 1 has reached its limit in this regard.

[0151] Flow field considerations The minimum threshold force required to apply to the molten metal entering the investment casting shell can be achieved by altering the mass of the molten metal entering the shell or by increasing its velocity, typically by decreasing one and increasing the other. There are practical limitations to the extent to which the mass of the "poured material" (molten metal) can be reduced. As the mass of the poured material is reduced, a correspondingly greater 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 turbulence in the molten metal entering the shell. Turbulence is undesirable because it disrupts the flow pattern of the molten metal. A disrupted flow pattern may require even greater force to "push" the metal through the main gate into the mold cavity.

[0152] The Reynolds number can be easily modified by changing the shape and / or size of the flow channel. For example, changing the R (flow radius) will directly affect the Reynolds number. A smaller R (flow radius) will result in a smaller minimum force (the two are almost mutually exclusive). Therefore, it is advantageous to first reduce the Reynolds number to maintain a stable flow field for the molten metal, and then meet the minimum force requirement by adjusting the amount of pouring material.

[0153] Other factors Another factor is the preheating of the investment casting shell before introducing the molten metal. Casting machine 1 achieves 94% throughput with the lowest Reynolds number and the lowest amount of material poured (and thus the lowest force), partly due to its highest shell preheating temperature. Another factor is the complexity of the module. Evaluating complex modules is very difficult, and the high Reynolds number often exhibited by such modules is not the only variable to be controlled to reduce destructive turbulence of the molten metal within them. For example, the number of "sharp turns" (90 degrees or more) in the module's flow channels and mold cavity is also a factor. Regarding... Figure 16 and Figure 17 The investment casting mold shell used by casting machine 1 has one sharp turn (and another less sharp turn), while the mold shell used by casting machine 6 has three sharp turns. It is possible that casting machine 6 needs to rotate its mold shell at a higher angular velocity to overcome the flow resistance caused by these sharp turns. However, this does not eliminate the disruptive flow pattern caused by the sharp turns. Therefore, an investment casting mold shell that includes a simpler mold (with fewer sharp turns to allow a more "natural" flow path for the molten metal) is needed.

[0154] Another factor is the matching of runners and gates. Compared to generally lower figures from other casting machines, casting machine 1 has the closest interfacial gate ratio to 100% (indicating an optimal gate). The “worst” is casting machine 3, whose investment casting shell has a Reynolds number almost as low as that of casting machine 1, yet it achieves only 78% throughput due to a poor interfacial gate ratio (approximately 23%). The low interfacial gate ratio exhibited by the shell of casting machine 3 increases the difficulty of determining whether the low throughput of casting machine 3 is due to insufficient pouring material filling the gate or the presence of “two-phase flow-liquid and vacancy.” In either case, the total cross-sectional area of ​​the runner and gate can be kept as close to equal as possible (and constant) to achieve a constant flow rate of liquid metal throughout the shell at any point during pouring. This principle is particularly applicable to the interface between the runner and the main gate for thin-walled titanium alloy castings, where the interfacial gate ratio should be no less than one (1.0).

[0155] Another factor is the cross-sectional shape of the runner. Comparing casting machines 4 and 5, and casting machines 2 and 5, triangular cross-section runners appear to produce a lower Reynolds number compared to circular or rectangular runners. Although using triangular cross-section runners may cause issues with the interfacial gate ratio (when metal flows from such a runner to a straight or circular cross-section gate), the significant reduction in Reynolds number achieved using triangular cross-section runners is worth pursuing, as indicated by the difference in pouring material used in casting machines 2 and 5 (39 kg vs. 32 kg).

[0156] Figure 19 The diagram shows a flowchart for configuring the module for investment casting shells. In the first step 301, overall considerations for the desired module are made, such as size, handling, and balancing. Next, the complexity of the module is reduced by minimizing sharp turns and any unnecessary (and of course, any frequent) changes in the runner cross-section (step 302). The interfacial gate ratio is kept as close to one as possible (step 303). Moreover, the Reynolds number is minimized as feasiblely as possible (step 304). The angular velocity (RPM) of the turntable is fine-tuned, and the shell preheating temperature is increased to produce the highest possible product yield (step 305). Iterations of steps 304 and 305 (306) are typically required to achieve a satisfactory yield. In step 308, after achieving a satisfactory yield (307), the mass of the pouring material (molten metal) is gradually reduced to decrease the force required to drive the molten metal to flow throughout the module without reducing product yield, while maintaining other casting parameters.

[0157] More information regarding investment casting methods and apparatus for casting thin-walled clubheads using titanium alloys and other materials can be found in U.S. Patent No. 7,513,296, published April 7, 2009, and U.S. Publication No. 2016 / 0175666, published June 23, 2016, both of which are incorporated herein by reference in their entirety. While these incorporated references disclose methods and systems for casting clubhead bodies excluding the faceplate (which is later attached to the body), the same or similar methods and systems can be used to cast the clubhead bodies disclosed herein with the same or similar benefits and advantages, wherein the faceplate in an integrally cast component of the body is not formed separately and is not later attached to the body.

[0158] Further information regarding coatings on molds used for casting titanium alloys, and methods for producing molds for casting titanium alloys with a calcium oxide face coating, can be found in U.S. Patent No. 5,766,329, published June 16, 1998, which is incorporated herein by reference in its entirety.

[0159] Including the clubhead with a cast titanium alloy body / face. Compared to titanium golf club faces formed using sheet machining or forging processes, cast faces offer advantages such as lower cost and greater design freedom. However, golf club faces cast from conventional titanium alloys such as 6-4 Ti require chemical etching to remove the alpha shell on one or both sides, ensuring the face's durability. This etching necessitates the use of hydrofluoric acid (HF), a difficult-to-handle, extremely harmful, environmentally polluting, and expensive chemical etchant.

[0160] Faces cast from titanium alloys (collectively referred to herein as “9-1-1 Ti”) 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) and optionally other small amounts of alloying elements and impurities can have a less pronounced α-shell, which makes hydrofluoric acid etching unnecessary or at least less necessary compared to faces made from conventional 6-4 Ti and other titanium alloys.

[0161] Furthermore, 9-1-1 Ti can possess minimum mechanical properties of 820 MPa yield strength, 958 MPa tensile strength, and 10.2% elongation. These minimum properties are likely significantly superior to those of typical cast titanium alloys such as 6-4 Ti, which can possess minimum mechanical properties of 812 MPa yield strength, 936 MPa tensile strength, and ~6% elongation.

[0162] Compared to a golf club head where the face is formed separately and later attached (e.g., welded or bolted) to the front opening in the club head body, a golf club head cast as a single integral part of the body (e.g., simultaneously cast as a single casting object) can offer superior structural properties. However, the advantages of having an integrally cast Ti face are diminished due to the need to remove the α-shell on the surface of the cast Ti face.

[0163] The drawbacks of having to remove the α-shell, which are present in the clubhead disclosed herein and comprise an integrally cast 9-1-1 Ti face and body unit, can be eliminated or at least significantly mitigated. For the cast 9-1-1 Ti face, using a conventional mold preheating temperature of 1000°C or greater, the thickness of the α-shell can be about 0.15 mm or less, or about 0.20 mm or less, or about 0.30 mm or less, such as between 0.10 mm and 0.30 mm in some embodiments. For the cast 6-4 Ti face, the thickness of the α-shell can be greater than 0.15 mm, or greater than 0.20 mm, or greater than 0.30 mm, such as from about 0.25 mm to about 0.30 mm in some embodiments.

[0164] In some cases, a reduced thickness (e.g., 0.15 mm or less) of the α-shell in a 9-1-1 Ti panel may not be thin enough to provide sufficient durability for the panel and avoid the need to etch away some of the α-shell with harsh chemical etchants such as HF acid. In such cases, the preheating temperature of the mold can be reduced (e.g., to below 800°C, below 700°C, below 600°C, and / or below or equal to 500°C) before pouring the molten titanium alloy into the mold. This can further reduce the amount of oxygen transferred from the mold to the cast titanium alloy, resulting in a thinner α-shell (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 for the cast body / face unit, which is particularly important for the panel.

[0165] The thinner alpha shell in the 9-1-1 Ti face contributes to enhanced durability, making the face durable enough that a portion of the alpha shell does not need to be removed from the face via chemical etching. Therefore, when casting the body and face integrally using 9-1-1 Ti, especially when using molds with lower preheating temperatures, hydrofluoric acid etching can be eliminated from the manufacturing process. This simplifies the manufacturing process, reduces costs, lowers safety risks and operational hazards, and eliminates the possibility of environmental pollution due to HF acid. Furthermore, because HF acid is not introduced into the metal, the body / face, or even the entire clubhead, can contain very few or substantially no fluorine atoms, defined as less than 1000 ppm, less than 500 ppm, less than 200 ppm, and / or less than 100 ppm, where the presence of fluorine atoms is due to impurities in the metallic material used to cast the body.

[0166] Variable facial thickness and facial bulge / protrusion characteristics In some embodiments, a face profile of variable thickness can be achieved on the face, as described, for example, 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 entire contents of which are incorporated herein by reference. Changing the face thickness can increase the size of the COR zone of a golf club head, commonly referred to as the sweet spot, which allows a larger area of ​​the face to consistently deliver high golf ball speed and forgiveness when the golf club head is struck. Furthermore, changing the face thickness can facilitate reducing the weight of the face area for redistribution to other areas of the club head. For example, as... Figure 9 As shown, panel 18 has a thickness defined between outer surface 22 and inner surface 40 of the inner cavity facing the golf club head. t Panel 18 may include a central portion 42 positioned adjacent to an ideal impact location 23 on the outer surface 22. The central portion 42 may have a thickness similar to, or slightly greater than, the thickness at the perimeter of the panel. Panel 18 may also include a diverging portion 44 extending radially outward from the central portion 42, which may be elliptical. The inner surface 40 may be symmetrical about one or more axes and / or asymmetrical about one or more axes. The thickness of the diverging portion 44... t The thickness increases radially outward from the center portion 42. Panel 18 includes a converging portion 46 extending from the diverging portion 44 via the transition portion 48. The thickness of the converging portion 46... tThe distance from the transition portion 48 radially outward generally decreases. In some cases, the transition portion 48 is the apex between the diverging portion 44 and the converging portion 46. In other embodiments, the transition portion 48 extends radially outward from the diverging portion 44 and has a generally constant thickness. t (See) Figure 7-9 ).

[0167] In some embodiments, the cross-sectional profile of panel 18 along any axis extending from the panel perpendicular to the ideal impact location 23 is generally similar to Figure 7-9 In other embodiments, the cross-sectional profile may vary, for example, it may be asymmetrical. For instance, in some embodiments, the cross-sectional profile of panel 18 along the z-axis of the rod head origin may include a central portion, a transition portion, a diverging portion, and a converging portion as described above (see [link to documentation]). Figure 7-9 However, the cross-sectional profile of panel 18 along the x-axis of the clubhead origin may include a second diverging portion extending radially from the converging portion 46 and connected to the converging portion via a transition portion. In an alternative embodiment, the cross-sectional profile of panel 18 along the z-axis of the clubhead origin may include a second diverging portion extending radially from the converging portion and connected to the converging portion, as described above with respect to variations along the x-axis of the clubhead origin.

[0168] In some embodiments of golf club heads with a face featuring a protrusion, the maximum face thickness is greater than about 4.8 mm, and the minimum face thickness is less than about 2.3 mm. In some embodiments, the maximum face thickness is between about 5 mm and about 5.4 mm, and the minimum face thickness is between about 1.8 mm and about 2.2 mm. In even more specific embodiments, the maximum face thickness is about 5.2 mm, and the minimum face thickness is about 2 mm. The face thickness should have a thickness variation of at least 25% over the face (thickest portion compared to thinnest portion) to save weight and achieve higher ball speed on off-center hits.

[0169] In some embodiments of golf club heads having a face with a protrusion and a thin sole or thin skirt construction, the maximum face thickness is greater than about 3.0 mm, and the minimum face thickness is less than about 3.0 mm. In some embodiments, the maximum face thickness is between about 3.0 mm and about 4.0 mm, between about 4.0 mm and about 5.0 mm, between about 5.0 mm and about 6.0 mm, or greater than about 6.0 mm, and the minimum face thickness is between about 2.5 mm and about 3.0 mm, between about 2.0 mm and about 2.5 mm, between about 1.5 mm and about 2.0 mm, or less than about 1.5 mm.

[0170] Figure 10 and Figure 11 A golf club head 4 with a shaft 3 is shown. The club head 4 includes a center face 5a, a heel 5b, a toe 5c, a crown 5d, and a sole 5e. The club head 4 also includes a face 6, which includes a curvature from the heel 5b to the toe 5c, commonly referred to as a bulge 8. The face 6 also includes a curvature from the crown 5d to the sole 5e, commonly referred to as a ridge 9. In at least one embodiment, the combination of curvatures can provide a face 6 having a generally toroidal shape or a cross-section similar to a toroidal surface. The face 6 also includes an X-axis X extending horizontally through the center face 5a from the heel 5b to the toe 5c; a Z-axis Z extending vertically through the center face 5a from the crown 5d to the sole 5e; and a line extending horizontally through the center face and into... Figure 10 The Y-axis, X-axis, Y-axis, and Z-axis in the page are mutually orthogonal.

[0171] like Figure 11 As shown, the clubhead 4 further has a center of gravity (CG) 5f inside the clubhead. The clubhead 4 has CG X-axis, CG Y-axis, and CG Z-axis that are orthogonal to each other and pass through CG 5f to define the CG coordinate system. The CG X-axis and CG Y-axis lie in a horizontal plane parallel to the flat ground surface. The CG Z-axis lies in a vertical plane orthogonal to the flat ground surface. In one embodiment, the CG Y-axis may coincide with the Y-axis, but in most embodiments, the axes do not coincide.

[0172] Figure 11 This is an enlarged depiction of the clubhead 4 striking the golf ball B on the heel 5b of the clubhead. This gives the golf ball B a clockwise rotation, which causes the ball to curve to the right during flight. As discussed above, striking the golf ball B on the heel 5b of the clubhead 4 will cause the golf ball to leave the clubhead 4 at an angle θ relative to the CG Y-axis of the clubhead 4. It will be understood that angle θ merely depicts the general angle at which the ball will leave the clubhead and is not intended to depict or imply the actual angle relative to the centerline or the point from which that angle will be measured. Angle θ further illustrates that the ball struck on the heel of the club will initially travel to the left of the centerline in its flight path.

[0173] The method used in this disclosure to obtain the values ​​is an optical comparator method. (Return to Reference) Figure 10The clubface 6 includes a series of score lines 11 that generally traverse the width of the clubface along the X-axis of the clubhead 4. In the optical comparator method, the clubhead 4 is mounted face down and approximately horizontally on a V-block mounted on an optical comparator. The clubhead 4 is oriented such that the score lines 11 are approximately parallel to the X-axis of the optical comparator. More precise orientation steps can also be used. Measurements are then taken at the geometric center point 5a on the clubface. Further measurements are then taken on either side of the geometric center point 5a and along the X-axis of the clubhead, 20 mm away from the geometric center point 5a, and on both sides of the center point and along the X-axis of the clubhead, 30 mm away from the geometric center point 5a. An arc is fitted through these five measurement points, for example, by using a radius function on the machine. This arc corresponds to the circumference of a circle with a given radius. This measurement of the radius refers to the measurement of the bulge radius.

[0174] To measure the bulge, the clubhead 4 is rotated 90 degrees so that the Z-axis of the clubhead is approximately parallel to the X-axis of the machine. Measurements are taken at the geometric center point 5a of the clubface. Further measurements are then taken 15 mm away from the geometric center point 5a and along the Z-axis of the clubface 6 on both sides of the center point, and 20 mm away from the geometric center point and along the Z-axis of the clubface on both sides of the center point. An arc is fitted through these five measurement points. This arc corresponds to the circumference of a circle with a given radius. This measurement of the radius refers to the measurement of the bulge radius.

[0175] The curvature is defined as 1 / R, where R is the radius of the circle corresponding to the bulge or rise in the measured arc. As an example, it has a curvature of 0.020 cm. −1 The bulge of curvature corresponds to the bulge measured by the bulge measuring arc, which is part of a circle with a radius of 50 cm. It has a curvature of 0.050 cm. −1 The bulge of the curvature corresponds to the bulge measured by the bulge measuring arc, which is part of a circle with a radius of 20 cm.

[0176] In some implementations, the faceplate of the disclosed clubhead may have the following properties: i) The curvature of the bulge is approximately 0.033 cm. −1 Approximately 0.066 cm −1 Between, and the bulge curvature is greater than 0 cm −1 And less than approximately 0.027 cm −1 ;and ii) The reciprocal of the bulge curvature is at least 7.62 cm greater than the reciprocal of the elevation curvature; and / or iii) The ratio Ro of the bulge curvature to the ridge curvature is greater than about 0.28 and less than about 0.75.

[0177] The use of vacuum die casting to produce the clubheads described in this article results in improved quality and reduced scrap. Furthermore, scrap due to high porosity is virtually eliminated, as is scrap after any secondary machining. Excellent surface quality is achieved while increasing product density and strength, thus enabling larger, thinner, and more complex castings. From a machining perspective, lower casting pressure is required, and tool and die life are extended. Waste of metal or alloy due to flash is also reduced or eliminated.

[0178] By utilizing a vacuum casting process, it has been surprisingly discovered that the titanium body and face of the disclosed clubhead exhibit a much smaller grain size than typically observed for similar titanium objects produced by investment casting, with a grain size of approximately 100 μm (micrometers) compared to the approximately 750 μm grain size of investment-cast titanium faces. More specifically, the titanium body / face disclosed herein can have a grain size of less than approximately 400 μm, preferably less than approximately 300 μm, more preferably less than approximately 200 μm, and even more preferably less than approximately 150 μm, and most preferably less than approximately 120 μm.

[0179] The titanium body / panel disclosed herein can also exhibit a much lower porosity than that typically observed for similar individually formed titanium panels produced by investment casting. More specifically, the titanium panels disclosed herein can have a porosity of less than 1%, preferably less than 0.5%, more preferably less than 0.1%.

[0180] The titanium body / panel disclosed herein can also exhibit yield strengths that are significantly higher than those typically observed for similar titanium panels made by investment casting, as measured by ASTM E8.

[0181] The titanium panels disclosed herein can also exhibit fracture toughness similar to that typically observed for similar titanium panels made by investment casting, and this fracture toughness is higher than that of similar panels made from wroughtmill-annealed products.

[0182] The titanium panels disclosed herein can also exhibit ductility as measured by percentage elongation reported in tensile tests, which is defined as the maximum elongation of the gauge length divided by the original gauge length, ranging from about 10% to about 15%.

[0183] The titanium panels disclosed herein may also exhibit a Young's modulus of 100 GPa + / - 10%, preferably 100 GPa + / - 5%, and more preferably 100 GPa + / - 2%, as measured by ASTM E-111.

[0184] The titanium panels disclosed herein may also exhibit ultimate tensile strengths of 970 MPa + / - 10%, preferably 970 MPa + / - 5%, and more preferably 970 MPa + / - 2%, as measured by ASTM E8.

[0185] The combination of the various properties described above allows for the manufacture of metal wood and titanium club heads with titanium panels that can be 10% thinner than similar panels manufactured by conventional investment casting, while maintaining, if not better, good strength properties.

[0186] In addition to the strength properties of the golf club head of the present invention, in some embodiments, the shape and size of the golf club head can be configured to produce an aerodynamic shape as described in U.S. Patent Publication No. 2013 / 0123040 A1, filed December 18, 2012, by Willett et al., the entire contents of which are incorporated herein by reference. The aerodynamics of the golf club head are also discussed in detail in U.S. Patents 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.

[0187] Besides the strength properties of the aft body and the aerodynamic properties of the clubhead, another set of properties that must be controlled for the clubhead are its acoustic properties, or the sound emitted by the clubhead when it strikes a golf ball. At the point of impact, the clubhead / golf ball deforms, causing vibrational modes of the clubhead associated with the crown, sole, or striking face to be excited. Most golf clubs have complex geometries, consisting of surfaces with varying curvatures, thicknesses, and materials, and accurate calculation of clubhead modes can be difficult. Clubhead modes can be calculated using computer-aided simulation tools. For the clubhead of this invention, the acoustic signal generated by the ball / club impact can be evaluated as described in co-pending U.S. Application No. 13 / 842,011, filed March 15, 2013, the entire contents of which are incorporated herein by reference.

[0188] In certain embodiments of the invention, the golf club head can be attached to the shaft via a removable head-shaft connection assembly, as described in detail in U.S. Patent No. 8,303,431, issued November 6, 2012, the entire contents of which are incorporated herein by reference. Furthermore, in some embodiments, the golf club head may also incorporate features that provide the golf club head and / or golf club with the ability not only to alternatively attach the shaft to the head, but also to adjust the loft and / or sole angle of the club by employing a removable head-shaft connection assembly. Such adjustable club sole / face connection assemblies are described in U.S. Patent No. 8,025,587, published September 27, 2011; U.S. Patent No. 8,235,831, published August 7, 2012; U.S. Patent No. 8,337,319, published December 25, 2012; and co-pending U.S. Publication No. 2011 / 0312437A1, filed June 22, 2011; U.S. Publication No. 2012 / 0258818A1, filed June 20, 2012; U.S. Publication No. 2012 / 0122601A1, filed December 29, 2011; and U.S. Publication No. 2012 / 0071264, filed March 22, 2011. More detailed description is provided in U.S. Application No. A1 and in co-pending U.S. Application No. 13 / 686,677, filed November 27, 2012, the entire contents of which are incorporated herein by reference.

[0189] In some embodiments, the golf club head may feature an adjustable mechanism disposed on the sole portion to separate the relationship between the face angle and the sheath / shaft loft, allowing for individual adjustment of both the square loft and face angle. For example, some embodiments of the golf club head may 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 the adjustable bottom portion are provided in U.S. Patent No. 8,337,319, filed December 25, 2012; U.S. Patent Publication No. US2011 / 0152000 A1, filed December 23, 2009; U.S. Patent Publication No. US2011 / 0312437, filed June 22, 2011; U.S. Patent Publication No. US2012 / 0122601 A1, filed December 29, 2011; and co-pending U.S. Application No. 13 / 686,677, filed November 27, 2012, the entire contents of which are incorporated herein by reference.

[0190] In some implementations, the movable weight can be adjusted by the manufacturer and / or user to adjust the position of the club's center of gravity to provide desired performance characteristics usable in a golf clubhead. This feature is described in the following U.S. Patents: 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, and 7,71... The contents of the patents described in more detail in patents 7,805, 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 are incorporated herein by reference in their entirety.

[0191] According to some embodiments of the golf club head described herein, the golf club head may also include a slidably repositionable weight positioned in the sole and / or skirt portion of the club head. Among other advantages, the slidably repositionable weight facilitates the end-user's ability to adjust the club head's CG (Gateway Center) to be positioned over a range of locations involving the repositionable weight. Further details regarding the features of the slidably repositionable weight are provided in more detail in U.S. Patent Nos. 7,775,905 and 8,444,505, filed May 20, 2013, and U.S. Patent Application No. 13 / 898,313, and U.S. Patent Application No. 14 / 047,880, filed October 7, 2013, the entire contents of each of these documents, together with the corresponding U.S. Patent Application No. 13 / 898,313, filed July 31, 2013. Paragraphs

[430] through

[470] and Figures 93-101 of U.S. Patent No. 13 / 956,046, published in U.S. Patent No. 2014 / 0080622, are hereby incorporated by reference; as are the contents of co-pending U.S. Patent Application No. 62 / 020,972, filed July 3, 2014, and co-pending U.S. Patent Application No. 62 / 065 / 552, filed October 17, 2014, respectively, which are hereby incorporated by reference.

[0192] 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, for example, a gap located on the sole portion and near the face of the club body. Such a coefficient of restitution feature is described more fully in the following: U.S. Patent Application No. 12 / 791,025, filed June 1, 2010; U.S. Patent Application No. 13 / 338,197, filed December 27, 2011; U.S. Patent Application No. 13 / 839,727 (U.S. Publication No. 2014 / 0274457A1), filed March 15, 2013; and U.S. Patent Application No. 14 / 457,883, filed August 12, 2014; and U.S. Patent Application No. 14 / 573,701, filed December 17, 2014, the entire contents of which are incorporated herein by reference.

[0193] Other exemplary clubheads Figure 20-36D Another exemplary golf club head 200, a type of wood, is illustrated, which may include any combination of the features disclosed herein. For example, the club head body 202 and face 270 may be cast from titanium alloy as a single structure, as discussed herein. The club head 200 includes a raised sole construction (see the benefits discussed in US 2018 / 0185719) and also includes two weight rails 214, 216 with slidably adjustable weight assemblies 210, 212. The club head 200 also includes both a crown insert 206 and a sole insert 208 (see [reference needed]). Figure 21 and Figure 22 (See the exploded view in the document), the insert can be constructed from various lightweight materials with multiple layers of fiber reinforcements arranged in a desired orientation pattern (see further details in US2018 / 0185719).

[0194] The clubhead 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 bottom insert 208 mounted inside the body on the top of the lower portion of the body, a front weight assembly 210 slidably mounted in the front weight rail 214, and a rear weight assembly 212 slidably mounted in the rear weight rail 216. The clubhead 200 includes a front sit pad or ground contact surface 226 between the front rail 214 and the face 270, and a rear sit pad or ground contact surface 224 on the heel side of the rear portion of the body to the rear rail 216, wherein the remainder of the bottom portion is raised above the ground when in the normal address position.

[0195] The clubhead 200 has a raised bottom defined by the combination of the body 202 and the bottom insert 208. For example, as in Figure 22 and Figure 27 As shown, the lower portion of the main body 202 includes a toe-side opening 240, a heel-side opening 242, and a rear rail opening 244, all of which are covered by the bottom insert 208. The rear counterweight rail 216 is positioned below the bottom insert 208.

[0196] The clubhead 200 also includes a toe-side cantilevered ledge 232 that extends around the perimeter of a toe region adjacent to the face, approximately from the rear weight rail 216 or rear seat 224, wherein the ledge 232 connects to a toe portion 230 of the body extending from the front seat 226 toward the toe. One or more optional ribs 236 can connect the toe portion 230 to a raised bottom at the front end of a toe-side opening 240 in the adjacent body. Three such triangular ribs... Figure 20 and Figure 26A The image in the middle shows...

[0197] The clubhead 200 also includes a heel-side cantilever flange 234 that extends rearward from near the sheath area to the seat 224 or to the rear end of the rear weight rail 216. In some embodiments, the two cantilever flanges 232 and 234 may meet and / or form a continuous flange extending around the rear of the clubhead. The seat 224 may optionally include a recessed rear portion 222 (e.g., Figure 26 (as shown in the image).

[0198] The lower portion of the body 202 forming a part of the bottom may include various features, thickness variations, ribs, etc., to provide enhanced rigidity when needed and weight savings when rigidity is less required. The body may include, for example, a thicker region 238 near the intersection of the two counterweight tracks 214, 216. The body may also include a thin flange or seat 260 surrounding openings 240, 242, wherein the flange 260 is configured to receive and mate with the bottom insert 208. The lower surface of the body may also include various internal ribs to enhance rigidity and acoustics, such as… Figure 27 and Figure 28 Ribs 262, 263, 265 and 267 are shown in the figure.

[0199] The upper portion of the body may also include various features, thickness variations, ribs, etc., to provide enhanced rigidity where needed and weight savings when rigidity is less critical. For example, the body includes a thinner seat region 250 surrounding the upper opening to receive the crown insert 206. Figure 21AAs shown, the seats 250 and 260 for the crown insert and the bottom insert can be close to each other around the outer perimeter of the body, and even share a common edge.

[0200] Figure 35A -D shows a top view of the club head 200 in various states, with the crown insert and bottom insert in place and / or removed. Figure 36A -D shows the crown insert and bottom insert in more detail. (See also...) Figure 36A and Figure 36B As shown, the sole insert 208 may have an irregular shape with a concave upper surface and a convex lower surface. The sole insert 208 may also include a notch 209 at the rear-heel end to accommodate a fit around the seat pad area 224, where enhanced rigidity is required due to ground contact forces. In various embodiments, the sole insert may 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 about 50% to 80% of the surface area of ​​the sole. The sole insert contributes to a clubhead structure that is sufficiently robust and rigid to withstand large dynamic loads applied to it, while remaining relatively lightweight to release discretionary mass that can be strategically distributed elsewhere within the clubhead.

[0201] The bottom insert 208 has a geometry and size selectively chosen to cover at least the bottom of the body with openings 240, 242, 244, and can be secured to the frame by adhesive or other fastening techniques. In some embodiments, the flange 260 may be provided with an indentation to receive a matching protrusion or matching ridge on the underside of the bottom insert to further secure and align the bottom insert to the frame.

[0202] Like the base, the crown also has an opening 246 that reduces the mass of the body 202 and, more significantly, the crown, which is the area of ​​the clubhead where the increase in mass has the greatest (undesirably) impact on the rise of the clubhead's CG. Along the perimeter of the opening 246, the frame includes a recessed flange 250 to seat and support the crown insert 206. (See Crown Insert 206) Figure 36C and Figure 36DThe crown insert has a geometry and dimensions compatible with the crown opening 246 and is secured to the body by adhesive or other fastening techniques to cover the opening 246. The flange 260 may have a notch along its length to receive a matching protrusion or matching ridge on the underside of the crown insert for further securing and aligning the crown insert to the body. The crown insert may also include a front protrusion 207 extending into the front crown portion 252 of the body.

[0203] In various embodiments, the flanges (e.g., flanges 250 and 260) of the body receiving the crown insert and the bottom insert can be made of the same metallic material as the body (e.g., titanium alloy), and thus can significantly increase the mass of the golf club head. In some embodiments, the width of the flange can be adjusted to achieve the desired mass contribution in order to control the flange's mass contribution to the golf club head. In some embodiments, if the flange adds too much mass to the golf club head, it may diminish the benefits of weight reduction for the bottom insert and crown insert, which can be made of lighter materials (e.g., carbon fiber or graphite composites and / or polymer materials). In some embodiments, the width of the flange can range from about 3 mm to about 8 mm, preferably from about 4 mm to about 7 mm, and more preferably from about 4.5 mm to about 5.5 mm. In some embodiments, the width of the flange can be at least four times the thickness of the respective insert. In some embodiments, the flange thickness 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 flange thickness 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. Although the flange can extend or run along the entire interface boundary between the respective insert and the body, in alternative embodiments, the flange can extend only partially along the interface boundary.

[0204] The perimeter of the crown opening 246 can closely follow the perimeter of the crown on the toe, heel, and back sides of the clubhead 200. Conversely, the face side of the crown opening 246 can be further spaced from the face 270 region of the clubhead. In this way, the clubhead can have additional frame mass and reinforcement in the crown region 252 directly behind the face 270. This region, and other adjacent areas of the face along the toe, heel, and bottom, support the face and withstand the relatively high impact loads and stresses caused by the ball striking the face. As described elsewhere herein, the frame can be made of a wide range of materials, including high-strength titanium, titanium alloys, and / or other metals. The opening 246 may have a notch on the front side that corresponds to the crown insert protrusion 207 to help align and position the crown insert on the body.

[0205] The front and rear weight rails 214 and 216 are positioned in the bottom of the clubhead and respectively define rails for mounting two-piece sliding weight assemblies 210 and 212, which can be fastened to the weight rails using fastening devices such as screws. The weight assemblies can be different from those shown above. Figure 21A The configuration shown can be installed in other ways and can be a single-piece or multi-piece design. The weight rail allows the weight assembly to be loosened for sliding adjustment along the rail and then tightened in place to adjust the effective CG and MOI characteristics of the clubhead. For example, by shifting the CG of the clubhead forward or backward via the rear weight assembly 212, or by shifting the CG of the clubhead heel or toe via the front weight assembly 210, the performance characteristics of the clubhead can be modified to affect the flight of the golf ball, particularly its spin characteristics. In other embodiments, the front weight rail 214 can alternatively be a front channel without movable weights.

[0206] The bottom of the main body 202 is preferably integrally formed with the front counterweight track 214, which is generally parallel to the face of the clubhead and extends near the face of the clubhead and generally perpendicular to the rear counterweight track 216, which extends rearward from near the middle of the front track toward the rear of the clubhead.

[0207] In the illustrated embodiment, each weight rail includes only one weight assembly. In other embodiments, two or more weight assemblies may be installed in any one or both of the weight rails to provide selectable mass distribution capability for the clubhead.

[0208] By adjusting the CG towards the heel or toe via the front weight rail 214, the clubhead's performance characteristics can be modified to influence ball flight, particularly the ball's tendency to draw or fade to the left and / or counteract its tendency to slice or hook to the right or left. By adjusting the CG forward or backward via the rear weight rail 216, the clubhead's performance characteristics can be modified to influence ball flight, particularly the ball's upward movement or counteracting its tendency to fall due to spin during flight. The use of two weight components in the weight rails allows for alternating adjustment and interaction between the two weights. For example, relative to the front rail 214, two independently adjustable weight components can be positioned entirely on the toe side, entirely on the heel side, positioned such that one weight entirely on the toe side and the other entirely on the heel side are spaced apart by the maximum distance, positioned together in the middle of the weight rail, or positioned in other weight positioning modes. As shown in the diagram, with a single counterweight assembly in the track, the weight adjustment option is more limited, but the effective CG of the bar head can still be adjusted along the continuum, such as towards the heel or toe, or in a neutral position where the counterweight is located at the center of the front counterweight track.

[0209] like Figures 29-34 As shown, each of the counterweight tracks 214, 216 preferably has a recess, which may be generally rectangular in shape, to provide a recessed track for positioning and guiding the counterweight as it slides adjustably along the track. Each track includes one or more perimeter guides or flanges to define an elongated channel, which preferably has a width dimension smaller than the width of the counterweight placed in the channel. For example, as Figure 29 and Figure 30 As shown, the front track 214 includes opposing perimeter guides 288 and 284, and as Figure 33 and Figure 34As shown, the rear track 216 includes opposing perimeter guides 290 and 292. In this way, the counterweight can slide within the counterweight track, while the guides prevent the counterweight from leaving the track. Simultaneously, the channel between the flanges allows the screws of the counterweight assembly to pass through the center of the outer counterweight element, through the channel, and then into threaded engagement with the inner counterweight element. The flanges serve to provide the track or guide on which the connected counterweight assembly slides freely, while effectively preventing the counterweight assembly from unintentionally slipping off the track (even if loose). In the front track 214, the inner counterweight member of assembly 210 is located in the inner recesses 280 and 286 above guides 284 and 288, while the outer counterweight member is partially located in the recess 282 between the front guide 284 and the overhanging lip 228 of the front seat cushion 226. Figure 30 , Figure 31 In the rear track 216, the internal counterweight members of the assembly 212 are located in the internal recesses 296 and 298 above the guide rails 290 and 292, while the external counterweight members may be located in the recess 294 between the heel side guide rail 290 and the overhanging lip 225 of the rear seat cushion 224.

[0210] The weight assembly can be adjusted by loosening the screws and moving the weight along the rail to the desired position, and then the screws can be tightened to secure the weight in place. The weight assembly can also be swapped or replaced with other weight assemblies of different masses to provide additional mass adjustment options. Adding a second or third weight to the weight rail provides numerous additional weight position and distribution options for further fine-tuning of the clubhead's effective CG position in heel-toe and fore-and-aft directions and their combinations. This also provides a wide range of adjustments to the clubhead's MOI properties.

[0211] Any one or both of weight assemblies 210 and 212 may comprise a three-piece assembly comprising an inner weight member, an outer weight member, and fasteners connecting the two weight members together. The assembly can be clamped to the front, rear, or side flanges of the weight track by tightening the fasteners, such that the inner member contacts the inside of the flange and the outer weight member contacts the outside of the flange, providing sufficient clamping force to hold the assembly relative to the body throughout a round of golf. The weight members and assemblies may be shaped and / or configured to be inserted into the weight track by inserting the inner weight member across the flange into an internal channel at an available portion of the weight track, as opposed to inserting the inner weight at an enlarged opening at one end of the weight track (in which case the weight assembly is not configured to be fixed in place). This allows for the elimination of such a wide, non-functional opening at the end of the track and allows for a shorter track or a longer functional flange width (along which the weight assembly can be fixed). To allow the internal counterweight to be inserted into the track (e.g., across the flange) in the middle of the track, the internal counterweight can be inserted at an angle not perpendicular to the flange, such as an angled insertion. The counterweight can be inserted at an angle and gradually rotated into the internal channel to allow insertion across the clamping flange. In some embodiments, the internal counterweight can have a circular, elliptical, oblong, arcuate, curved, or otherwise specifically shaped structure to better allow the counterweight to be inserted into the channel across the flange at a usable portion of the track.

[0212] In the golf club head disclosed herein, the ability to adjust the relative position and mass of a slidably adjustable and / or threadedly adjustable weight, combined with the weight savings achieved by the use of titanium alloy materials and the combination of lightweight crown inserts and / or sole inserts, and further combined with the discretionary mass provided by the raised sole configuration, allows for a wide range of variations in many properties 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 properties, the club head's aesthetic appearance and subjective feel properties, and / or other properties.

[0213] In some embodiments, the front and rear counterweight tracks have certain track widths. The track width can be measured, for example, as the horizontal distance between a first track wall and a second track wall, which are substantially parallel to each other on opposite sides of the inner portion of the track that receives the inner counterweight member of the counterweight assembly. (Reference) Figures 29-31 The width of the front track 214 can be the horizontal distance between the opposing walls of the internal recesses 280 and 286. (See reference) Figures 32-34The 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 and rear tracks, the track width can be between approximately 5 mm and approximately 20 mm, such as between approximately 10 mm and approximately 18 mm, or such as between approximately 12 mm and approximately 16 mm. According to some embodiments, the track depth (i.e., the vertical distance between the uppermost inner wall of the track and the imaginary plane containing the bottom region of the outermost outer edge adjacent to the track) can be between approximately 6 mm and approximately 20 mm, such as between approximately 8 mm and approximately 18 mm, or such as between approximately 10 mm and approximately 16 mm. For the front track 214, the track depth can be the vertical distance from the inner surface of the overhanging lip 228 to the upper surface of the inner recess 280. Figure 30 For 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 internal recess 296. Figure 34 ).

[0214] Furthermore, both the front and rear rails have a certain rail length. The rail length can be measured as the horizontal distance between the relative longitudinal endwalls of the rails. For both the front and rear rails, their rail lengths can be between approximately 30 mm and approximately 120 mm, such as between approximately 50 mm and approximately 100 mm, or such as between approximately 60 mm and approximately 90 mm. Alternatively, the length of the front rail can be expressed as a percentage of the hitting face length. For example, the front rail can be between approximately 30% and approximately 100% of the hitting face length, such as between approximately 50% and approximately 90% of the hitting face length, or such as between approximately 60% and approximately 80% of the hitting face length.

[0215] The track depth, track width, and track length properties described above can also be similarly applied to the front channel 36 of the clubhead 10.

[0216] exist Figure 30 and Figure 34 As can be seen, the lip 228 of the front seat cushion and the lip 225 of the rear seat cushion extend above or over the corresponding counterweight rails, limiting the rail openings and helping to keep the counterweights within the rails.

[0217] refer to Figure 34When the clubhead is in the address position relative to the ground, the bottom area on the heel side of the rear rail 216, on the seat 224, is significantly lower vertically than the bottom area on the toe side (the bottom of the flange 292). This can be considered a clubhead with a "dropped sole" or "raised sole" construction, where a portion of the sole (e.g., on the heel side) is positioned lower than 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 seat 224) is raised relative to another portion of the sole (e.g., the seat itself). The same applies to the front rail 214, where, in the normal address position, the front seat 226 and its lip 228 are significantly lower than the rear side of the front rail (e.g., the bottom of the flange 292). Figure 30 (as shown in the image).

[0218] In one embodiment, the vertical distance between the level of the ground contact surface of the seat cushion and the adjacent surface of the raised bottom portion can be in the range of about 2-12 mm, preferably about 3-9 mm, more preferably about 4-7 mm, and most preferably about 4.5-6.5 mm. In one example, the vertical distance is about 5.5 mm.

[0219] Figures 37-48 Another exemplary golf club head 400 is illustrated, having a face portion integrally cast as a single unit with the front portion of the club head body to form a cup-shaped unit (referred to herein as cup 402). This cup-shaped unit includes the face portion, insert, and front portions of the crown, sole, toe, and heel. However, the rear portion of the body (referred 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 herein to as the body of club head 400. Crown insert 406 and sole insert 408 can then 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 comprises a metallic material, a composite material, and / or other materials.

[0220] Figure 37 and Figure 38An assembled clubhead 400 is shown, including a cup 402, a ring 404, a crown insert 406, and a sole insert 408. A head-shaft connection assembly 410 can be coupled to a sheath 412. The cup 402 and ring 404 can be made of metallic materials such as titanium alloys or steel, while the inserts 406 and 408 can be made of less dense materials, such as carbon fiber reinforced composites. Any other materials disclosed herein can also be used in the clubhead 400. The cup and ring can be made of the same material (e.g., the same titanium alloy), or the ring can be made of a different material than the cup (e.g., a steel ring and a titanium alloy cup, or two different titanium alloys).

[0221] Figure 39 and Figure 40 The illustration shows how a ring 404 is attached to a cup 402 at toe and heel joints 420, forming an annular body with an upper crown opening and a lower bottom opening. The ring 404 may include a forward-extending toe and heel joint end 424 that mates with a rearward-extending toe and heel joint end 422 of the cup 402 to form a joint 420. In the illustrated example, the ring has a male protrusion that matches a female notch in the cup. However, these joints can be reversed so that the male protrusion is on the cup and the female notch is in the ring. In other embodiments, any other suitable engagement geometry may be used for the joint 420 to attach the ring to the cup. The joint 420 may be formed by any suitable means such as welding, brazing, adhesives, mechanical fasteners, etc.

[0222] In some embodiments, the joint 420 may be positioned at a sufficient distance from the striking face to avoid potential failure due to the severe impact experienced by the golf club when striking a golf ball. For example, in some embodiments, the joint 420 may be positioned behind the center face of the clubhead at a distance of at least 20 mm, at least 30 mm, at least 40 mm, at least 50 mm, at least 60 mm, and / or from 20 mm to 70 mm, as measured along the y-axis (front-back direction).

[0223] Figure 41The diagram illustrates how inserts 406 and 408 can be attached to the body to cover the crown opening and the bottom opening and surround the internal cavity of the clubhead. Crown insert 406 can be attached to a crown flange 426 of the body extending around the crown opening, while bottom insert 408 can be attached to a bottom flange 428 of the body extending around the bottom opening. Flanges 426 and 428 can be formed by a combination of a cup 402 and a ring 404, wherein the cup includes the front portion of the flange and the ring includes the rear portion of the flange. Flanges 426 and 428 can be offset inward from their surrounding outer surfaces, creating space for receiving inserts, wherein the outer surface of the inserts is even or flush with the surrounding outer surface of the cup / ring body. Ring 404 may also include a protrusion 430 extending downward and forward from the rear of the ring and forming part of the bottom flange 428 to help support the bottom insert 408 and provide increased rigidity.

[0224] In some embodiments, ring 404 may include a mass pad, such as having increased thickness in or elsewhere in the protrusion 430, to provide rear weighting to the golf club and move the center of mass rearward, increasing the MOI around the z-axis and x-axis. This rear weighting may also be achieved using additional weighting members attached to the rear ring, such as removable, interchangeable, and / or adjustable weighting members attached to the rear portion of the ring. For example, protrusion 430 or other portions of ring 404 may include openings, such as threaded openings, rails, or other weighting member receiving features. Figure 47 An example of two counterweight ports 431 and 433 that can receive such an adjustable counterweight component is shown. Two or more counterweight components can also be simultaneously attached to the rear ring. The mass pad or counterweight component can contain a relatively denser material, such as tungsten or steel.

[0225] In some embodiments, the cup 402 may include a mass pad, such as mass pad 432 shown in the figures, in a bottom region at the bottom to lower and / or move the center of mass forward. In some embodiments, the cup 402 may include one or more additional weight members attached to a bottom portion of the cup (such as in or near the mass pad 432 and / or the rear of the slot 418), such as one or more removable, interchangeable, and / or adjustable weight members attached to the cup. For example, the mass pad 432 or other portions of the cup 402 may include one or more openings, such as threaded openings, rails, or other weight member receiving features. Two or more weight members may also be attached to the cup simultaneously. The weight members may contain a material that is relatively denser than the casting cup material, such as tungsten or steel. In some embodiments, the cup and ring may have matching weight ports that allow for swapping of weight members between a rear ring position and a lower cup position, providing adjustability options to change the mass properties of the clubhead. In some such instances, a set of interchangeable weights may be provided with the clubhead, such as 1-3 g weights and 8-15 g weights, which may be attached to a weight port in the rear ring or to a weight port in the bottom portion of the cup. This may allow for higher MOI (heavier weight in the rear) or lower spin (heavier weight in the low-forward location) or other combinations and mass properties.

[0226] Figure 44-47 The main body formed by the connected cup 402 and ring 404 is shown in more detail from several perspectives, without the inserts 406 and 408. Figure 44 This is a front view showing the integrated face 434. Figure 45 This is a side view of the base. Figure 46 It 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 and heel connectors 420 and the crown flange 426 that receive the crown insert 406. Figure 47 This is a bottom view showing the front bottom portion 438 and the flange 428 that receives the bottom insert 408. The front bottom portion 438 includes a bottom slot 418 that extends into the internal cavity of the clubhead. Figure 47The diagram also shows an exemplary rear weight port 431 located in the annular protrusion 430 and an exemplary bottom weight port located in the cup 402 at the rear of the slot 418 in the region of the mass pad 432. In other embodiments, such weight ports may be located in other parts of the cup or ring, such as in the very rear of the ring, and there may be more than two such weight ports. The weight ports may be threaded and may receive adjustable weight components, thereby allowing adjustability of the clubhead's center of mass and MOI properties.

[0227] Cup 402 Figure 42 and Figure 43 It is shown in more detail on the map. Figure 43 The rear surface of face 434 is shown in the figure. As described elsewhere herein, the rear portion of face 434 can be formed with a variety of complex shapes and thickness profiles and can be easily accessed from the rear portion before ring 404 is attached to cup 402 for machining, etching, material removal and / or other post-casting processing. Figure 43 A mass pad 432 on the bottom portion 438 of the cup is also shown. The mass pad 432 may include a thickened portion of the bottom with increased mass, which significantly affects the overall mass properties of the clubhead. The mass pad 432 may have a center notch with greater mass on the center toe and heel sides for enhanced mass and MOI properties. More information about the mass pad 432, alternative mass pad geometries and embodiments, and related properties can be found in U.S. Publication 2018 / 0126228, published May 10, 2018, which is incorporated herein by reference in its entirety.

[0228] Figure 48 The illustration shows a clubhead-shaft connection assembly 410 that allows the sheath 412 of the clubhead 400 to be attached to the shaft in more than one selectable orientation, allowing adjustment of the assembled golf club's loft, sole angle, and / or face angle in the normal address position. Assembly 410 may include various components, such as Figure 48 The sleeve 450, ferrule 452, sheath insert 454, fastener 456, and washer 458 are shown. Further information regarding adjustable clubhead-shaft connections can be found in U.S. Patent 9,033,821, published May 19, 2015, which is incorporated herein by reference in its entirety.

[0229] Figure 49 and Figure 50 The illustration shows a portion of the method for manufacturing a golf club head, and in particular a portion of the method for manufacturing a mold for casting the front cup 402 of the club head 400. Figure 49A wax cup 500 is shown, which 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 the wax face is then placed into a slightly larger face opening in the wax cup frame 502. Two wax pieces are then wax-welded around their annular joint 506 by adding hot liquid wax to the joint and allowing it to cool and fuse the face to the frame. The added hot wax fills the joint 506 and joins the wax cup frame 502 and the wax face 504 into a single integral wax cup 500. After the wax cools, excess wax can be removed from the front and rear of the welded joint 506. In some embodiments, the wax face 504 may include a prong 508 that extends radially outward and contacts the front surface 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 surface of the wax cup 500 across the joint 506 is flat and smooth. Wax protrusions 508 can be removed after the wax welding process.

[0230] Figure 50 Another example of a wax cup 510 is shown, which is formed by wax welding the wax cup frame and the wax surface together via an additional layer of wax around a joint 516, by optionally using wax protrusions 518 on the wax surface 514 to help set the depth of the wax surface in the opening of the wax cup frame 512. In this example, the wax cup 510 includes an additional protrusion 520 that creates an additional gate in the resulting mold to help facilitate the uniform flow of molten metal toward the face portion of the mold. Wax cups 500 and 510 may also include gate-generating portions in other locations, such as on the heel side near the sheath as illustrated, in the rear side of the face, and / or in other locations.

[0231] A wax cup is formed from two separate wax pieces (e.g., as in...) Figure 49 and Figure 50(In the middle) This allows for the creation of more complex geometries for wax cups and facilitates the formation of several different geometric implementations in a simplified, faster, and cost-effective manner. Starting with two separate wax pieces leads to the separation of the tooling and forming processes for the wax frame from those for the wax surface. Regarding the wax cup 500, the same wax cup frame 502 (and the same tooling) can be combined with any of several differently formed wax surfaces 504 to produce a corresponding number of different wax cups, meaning that only the tooling of the wax surface needs to be changed to produce different wax cups. For example, the manufacturer can produce two identical wax frames 502, and then combine one wax frame with a first wax surface, and can combine a second wax frame with a second wax surface having a different thickness profile than the first wax surface. The two different wax cups, as well as the resulting molds and the final product metal cup, can then be measured, compared, tested, etc. See various exemplary face thickness profiles. Figures 51-54 This relates to the discussion in this article. Therefore, using a two-part wax cup molding process can offer advantages in rapid prototyping and other manufacturing and development efficiencies.

[0232] Starting with two separate wax pieces also allows for the efficient production of large quantities of wax pieces, as each wax piece is smaller and can be produced in larger batches on the same tree.

[0233] Once the wax cup (e.g., 500 or 510) is produced, it can be used to form a mold for casting a metal cup (e.g., cup 402). The mold can contain ceramic material and / or any other suitable material for casting the metal cup. Once the mold is formed around the wax cup, the wax can be melted and expelled from the mold. Various subsequent steps can then be applied to prepare the mold for casting, including adding gates and / or surface treatments to the mold. Furthermore, several cup molds can be combined into a mold tree for simultaneously casting several metal cups. After the mold is prepared, molten metal can then be introduced into the mold to cast the metal cup. The mold can then be opened / removed to access the cast metal cup. The cast metal cup can be formed from any suitable metal or metal alloy, including titanium alloys (any suitable metallic material disclosed herein can be used for casting cups).

[0234] After a metal cup is cast, portions of the cast cup can be machined or modified to remove parts of the cast cup as needed. For example, the front surface of the face portion of the cup can be machined to add horizontal scribing and / or to create more precise textures, curvatures, and twists. As another example, the rear surface of the face portion of the cup can be machined to modify the thickness profile across the height and width of the face portion, thereby creating the desired variable thickness profile across the face portion. The front and / or rear surfaces of the face portion of the cast cup can also be machined or chemically etched (e.g., using hydrofluoric acid) to remove part or all of the α-shell formed during the casting process (e.g., for titanium alloys), such as making the face portion less brittle and increasing its durability.

[0235] In the anticipated scenario where the material is removed after casting from the face portion of the cup, the face portion of the cup can be cast with an additional thickness of material, so that the required amount of material and the required thickness profile are left after the material is removed following casting.

[0236] like Figure 39 and Figure 40 As shown and discussed above, the cup 402 and ring 404 can be formed separately (e.g., cast) and then combined at joint 420 (e.g., welded, brazed, adhesively bonded, mechanically fastened, etc.) to form a metal clubhead body that serves as a rigid frame for receiving other components to form the golf clubhead 400. One advantage of this method of producing the clubhead body from separate cup 402 and ring 404 is that the absence of a rear ring portion allows for better access to the rear surface of the face portion of the cup 402 for post-cast machining, chemical etching, and / or other post-cast modifications. For example, in the absence of ring 404, more space is available for cutting tools, milling machines, CNC machine tools, drill bits, or other tools to access the entire rear surface of the face portion of the cup 402. After such post-cast modifications to the cup 402, ring 404 can be attached to the cup, and the rest of the clubhead can be assembled.

[0237] Another advantage of casting the cup and ring separately is that it allows for efficient mass production of each of the ring and cup components, as each casting is smaller than the assembled body and can be produced in larger batches on the same tree. Furthermore, the same ring component can be used with a variety of differently shaped cup components, thus requiring only changes to the tooling used for the cup to accommodate variations in the clubhead body, or the use of different cup / face geometries to create several different variations of the clubhead.

[0238] Figure 51The illustration shows an exemplary rear surface of the face portion of a cast cup 600, similar to cup 402, as viewed from the rear portion where the sheath / heel is on the left and the toe is on the right. Figure 52 and Figure 53 Another exemplary facial portion 700 with a variable thickness profile is illustrated, and Figure 54 The illustration shows another exemplary face portion 800 with a variable thickness profile. Due to the casting process and optional post-cast modifications to the face portion, the face portion of the cast cup can have a variety of novel thickness profiles. By casting the face into the desired geometry, rather than forming the panel from a flat-rolled sheet of metal in conventional processes, the face can be produced with a wider range of geometries and can have different material properties, such as different grain orientations and chemical impurity contents, which can provide advantages for golf ball performance and manufacturing.

[0239] In conventional processes, the panel is formed from a flat metal sheet of uniform thickness. This sheet is typically rolled along an axis to reduce the thickness to a uniform thickness across the sheet. This rolling process can impart a grain orientation in the sheet that produces different material properties in the direction of the rolling axis compared to a direction perpendicular to the rolling direction. This change in material properties can be undesirable and can be avoided by alternatively using the disclosed casting method to produce the face portion.

[0240] Furthermore, because conventional panels begin with flat sheets of uniform thickness, the total sheet thickness must be at least as large as the maximum thickness of the desired final product panel. This means that much of the initial sheet material must be removed and wasted, increasing material costs. In contrast, in the disclosed casting method, the face portion is initially formed to more closely resemble the final shape and quality, and far less material must be removed and wasted. This saves time and cost.

[0241] Furthermore, in conventional processes, the initially flat metal sheet must be bent in a specific process to give the panel the desired bulge and curvature. This bending process is not required when using the disclosed casting method.

[0242] Figures 51-54The unique thickness profile illustrated in the middle can be produced using the disclosed casting method, and is previously impossible to achieve using conventional processes, in which a sheet of metal of uniform thickness is mounted on a lathe or similar machine and turned to produce a variable thickness profile across the rear of the panel. In this turning process, the resulting thickness profile must be symmetrical about a central turning axis, which limits the thickness profile to components of concentric toroidal shapes, each of which has a uniform thickness at any given radius from the center point. In contrast, the disclosed casting method does not impose such restrictions and can produce more complex facial geometries.

[0243] By using the casting method disclosed herein, large quantities of the disclosed clubheads can be manufactured more quickly and efficiently. For example, 50 or more Cup 402 can be cast simultaneously on a single casting tree, whereas using a lathe with conventional milling methods would take much longer and require more resources to create a new face thickness profile on the face one at a time.

[0244] exist Figure 51 In this design, the rear face surface of the cast cup 600 includes an asymmetrical variable thickness profile, illustrating only one example of the various variable thickness profiles that can be achieved using the disclosed casting method. The center 602 of the face may have a center thickness, and the face thickness gradually increases radially outward from the center across an inner blend zone 603 to a maximum thickness ring 604, which may be circular. The face thickness gradually decreases radially outward from the maximum thickness ring 604 across a variable blend zone 606 to a second ring 608, which may be non-circular, such as elliptical. The face thickness gradually decreases radially outward from the second ring 608 across an outer blend zone 609 to a heel and toe region 610 and / or a radial perimeter region 612 of constant thickness (e.g., the minimum thickness of the face portion), which defines the extent of the face portion where the face transitions into the remainder of the cast cup 600.

[0245] 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 its circumferential position about the center 602. Similarly, the variable transition region 606 can have a thickness profile that varies as a function of its circumferential position about the center 602, and provide a thickness transition from the maximum thickness ring 604 to the second ring 608 with variable and smaller thicknesses. For example, the variable transition region 606 to the second ring 608 can be divided into... Figure 51The eight sectors, labeled AH, include top sector A, top-toe sector B, toe sector C, bottom-toe sector D, bottom sector E, bottom-heel sector F, heel sector G, and top-heel sector H. These eight sectors can have different angular widths as shown, or they can each have the same angular width (e.g., one-eighth of 360 degrees). Each of the eight sectors can have its own thickness variation, each ranging from the common maximum thickness of adjacent rings 604 to different minimum thicknesses at the second ring 608. For example, the second ring can be thicker in sectors A and E, and thinner in sectors C and G, with intermediate thickness in sectors B, D, F, and H. In this example, sectors B, D, F, and H can vary in thickness both radially (thinning outwards) and circumferentially (thinning from sectors A and E toward sectors C and G).

[0246] An example of the cast cup 600 may have the following thicknesses: 3.1 mm at the center 602, 3.3 mm at the ring 604, the second ring 608 may vary from 2.8 mm in zone A to 2.2 mm in zone C to 2.4 mm in zone E to 2.0 mm in zone G, and 1.8 mm in the heel and toe zones 610.

[0247] Figure 52 and Figure 53 Another exemplary cast facial portion 700 is shown with a rear facial surface including an asymmetrical variable thickness profile. The center 702 of the face may have a center thickness, and the facial thickness gradually increases radially outward from the center across an inner transition region 703 to a maximum thickness ring 704, which may be circular. The facial thickness gradually decreases radially outward from the maximum thickness ring 704 across a variable transition region 705 to an outer region 706, which includes more than one wedge-shaped sector AH with different thicknesses. Figure 53 As best illustrated, sectors A, C, E, and G can be relatively thick, while sectors B, D, F, and H can be relatively thin. An outer transition region 708 surrounding the outer region 706 transitions downwards in thickness from the variable sectors to a perimeter ring 710 with a relatively small but constant thickness. The outer region 706 may also include transition regions between each of sectors A and H, which gradually transition in thickness from one sector to the adjacent sector.

[0248] An example of the face portion 700 may have the following thicknesses: 3.9 mm at the center 702, 4.05 mm at the ring 704, 3.6 mm at area A, 3.2 mm at area B, 3.25 mm at area C, 2.05 mm at area D, 3.35 mm at area E, 2.05 mm at area F, 3.00 mm at area G, 2.65 mm at area H, and 1.9 mm at the perimeter ring 710.

[0249] Figure 54 Another exemplary cast face portion 800 is shown, the rear face including an asymmetrical variable thickness profile with a target thickness offset toward the heel side (left side). The center 802 of the face has a central thickness, and for the toe / top / bottom, the thickness gradually increases across an inner transition zone 803 to an inner ring 804, which has a larger thickness at its center. The thickness then decreases radially outward across a second transition zone 805 to a second ring 806, which has a thickness less than that of the inner ring 804. The thickness then decreases radially outward across a third transition zone 807 to a third ring 808, which has a thickness less than that of the second ring 806. The thickness then decreases radially outward across a fourth transition zone 810 to a fourth ring 811, which has a thickness less than that of the third ring 808. The toe region 812 transitions across an outer transition zone 813 to an outer perimeter 814 with a relatively smaller thickness.

[0250] For the heel side, the thickness offset is set by an amount (e.g., 0.15 mm) to be slightly thicker than their corresponding regions on the toe side. Thickening regions 820 (dashed lines) provide transitions where all thicknesses gradually increase towards the thicker offset regions 822 (dashed lines) on the heel side. In offset region 822, ring 823 is a set amount thicker than ring 806 on the heel side (e.g., 0.15 mm), and ring 825 is the same set amount thicker than ring 808. Transition regions 824 and 826 gradually decrease in thickness as they move radially outward and are each thicker than their corresponding transition regions 807 and 810 on the toe side. In thickening region 820, inner ring 804 gradually increases in thickness as it moves towards the heel.

[0251] An example of the face portion 800 may have the following thicknesses: 3.8 mm at the center 802, 4.0 mm at the inner ring 804 and thickened to 4.15 mm across the thickening region 820, 3.5 mm at the second ring 806, 3.65 mm at the ring 823, 2.4 mm at the third ring 808, 2.55 mm at the ring 825, 2.0 mm at the fourth ring 811, and 1.8 mm at the perimeter ring 814.

[0252] Figure 54 The targeted offset thickness profile shown can help provide a desirable feature time (CT) profile across the face. For example, thickening the heel side can help avoid CT spikes on the heel side of the face, which can help avoid an undesirable CT profile (non-conforming CT profile) across the face. This offset thickness profile can be similarly applied to the toe side of the face, or both the toe and heel sides, to avoid CT spikes on both the heel and toe sides of the face. In other embodiments, the offset thickness profile can be applied to the upper side of the face and / or towards the bottom side of the face.

[0253] Various other different facial thickness profiles can be produced 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 which are incorporated herein by reference. For example, U.S. Patent No. 9,975,018 discloses an example of a striking face including locally hardened regions, such as an inverted conical or “circular” thickness profile offset from the center of the face, which alter the launch conditions of a golf ball struck by a clubhead in a manner that fully or partially compensates for, overcomes, or prevents right / left deviation. Specifically, the locally hardened area is positioned on the striking surface so that a golf ball struck under normal conditions will not impart left and / or right sidespin.

[0254] All the disclosed facial thickness profiles can be produced using the casting method disclosed herein. This configuration would be impossible using conventional turning processes that remove material from the rear of an initially flat panel in a concentric circle pattern.

[0255] In some golf club head implementations, the faceplate can be cast separately and then welded to the front opening in the frame of the club head. When the faceplate is welded to the front opening of the frame, excess material is typically generated around the weld area, and this excess material must be removed after the welding process to smooth the transition between the faceplate and the frame. This process can be avoided by casting the entire cup, including the faceplate and the front frame, as a single casting unit as disclosed herein.

[0256] However, casting the panels individually can offer advantages over casting the entire cup as a single unit. For example, when the cast panels are part of the cup, post-processing the cast panels is much easier than post-processing the face surfaces. Figure 55 and Figure 56 The front portion 902 and rear portion 904 of an exemplary cast panel 900 are shown. In particular, all portions of the rear surface of the cast panel are more easily accessible than the rear face surface of a cast cup. Since there are no obstructions such as bottom, crown, toe, heel, or sheath, there is virtually unlimited space to access the cast panel using tools for any desired post-casting processes. Furthermore, the cast panel can be cast to more closely approximate the precise final shape of the panel, resulting in less material to be removed and less work required to modify the face after casting. For example, the panel 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 to be removed on each side of the face after casting. This equates to removing less waste material compared to machining a panel from a flat, rolled sheet of metal. The front surface of the cast face can be machined to remove some or all of the α-shell, achieving precise bulges, elevations, and tortuosity curvature and / or adding scribing. The rear of the cast face can be machined to remove part or all of the α-shell and / or achieve a precise variable thickness profile across the face. As described elsewhere in this paper, the casting process allows for more complex and asymmetrical thickness profiles, in contrast to the required 360-degree concentric circle symmetry of conventional face sheet turning processes.

[0257] Golf club heads cast as a single integral part of the face (e.g., simultaneously cast as a single casting object) offer superior structural properties compared to club heads where the face is formed separately and later attached (e.g., welded or bolted) to a front opening in the club head body. However, the advantage of having a single-piece cast Ti face is mitigated by the need to remove the α-shell on the surface of the cast Ti face.

[0258] The clubheads disclosed herein, comprising integrally cast titanium alloy face and body units (e.g., cast cups), eliminate or at least substantially reduce the disadvantage of having to remove the alpha shell. For cast 9-1-1 Ti faces, using a mold preheating temperature of 1000°C or greater, the thickness of the alpha shell can be about 0.10 mm or less, 0.15 mm or less, or about 0.20 mm or less, or about 0.30 mm or less, such as between 0.10 mm and 0.30 mm in some embodiments. For cast 6-4 Ti faces, the thickness of the alpha shell can be greater than 0.10 mm, greater than 0.15 mm, or greater than 0.20 mm, or greater than 0.30 mm, such as from about 0.25 mm to about 0.30 mm in some instances. In some embodiments, the alpha shell thickness can be as low as 0.1 mm and as high as 0.15 mm while providing a product with a desirablely high CT time across the face. In some implementations, the α-shell on 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, and this can be achieved without chemical etching of the surface after formation.

[0259] Other titanium alloys that can be used to form any of the striking surfaces and / or clubheads described herein may include titanium, aluminum, molybdenum, chromium, vanadium, and / or iron. For example, in a representative embodiment, the alloy may be an α-β titanium alloy containing 6.5% to 10% Al, 0.5% to 3.25% Mo, 1.0% to 3.0% Cr, 0.25% to 1.75% V, and / or 0.25% to 1% Fe by weight, with the balance comprising Ti (an example sometimes referred to as "1300" titanium alloy).

[0260] In another representative embodiment, the alloy may contain 6.75% to 9.75% Al by weight, 0.75% to 3.25% or 2.75% Mo by weight, 1.0% to 3.0% Cr by weight, 0.25% to 1.75% V by weight and / or 0.25% to 1% Fe by weight, with the balance being Ti.

[0261] In another representative embodiment, the alloy may contain 7% to 9% Al by weight, 1.75% to 3.25% Mo by weight, 1.25% to 2.75% Cr by weight, 0.5% to 1.5% V by weight and / or 0.25% to 0.75% Fe by weight, with the balance being Ti.

[0262] In another representative embodiment, the alloy may contain 7.5% to 8.5% Al, 2.0% to 3.0% Mo, 1.5% to 2.5% Cr, 0.75% to 1.25% V and / or 0.375% to 0.625% Fe by weight, with the balance being Ti.

[0263] In another representative embodiment, the alloy may contain 8% Al, 2.5% Mo, 2% Cr, 1% V, and / or 0.5% Fe by weight, with the balance being Ti. This titanium alloy may have the formula Ti-8Al-2.5Mo-2Cr-1V-0.5Fe. As used herein, "Ti-8Al-2.5Mo-2Cr-1V-0.5Fe" refers to a titanium alloy containing any of the elements mentioned above in any proportion. Some embodiments may also contain trace amounts of K, Mn, and / or Zr and / or various impurities.

[0264] Ti-8Al-2.5Mo-2Cr-1V-0.5Fe can possess minimum mechanical properties of 1150 MPa yield strength, 1180 MPa ultimate tensile strength, and 8% elongation. These minimum properties are significantly superior to other cast titanium alloys, including 6-4 Ti and 9-1-1 Ti, which can possess the aforementioned minimum mechanical properties. In some embodiments, Ti-8Al-2.5Mo-2Cr-1V-0.5Fe can have a tensile strength from about 1180 MPa to about 1460 MPa, a yield strength from about 1150 MPa to about 1415 MPa, an elongation from about 8% to about 12%, an elastic modulus of about 110 GPa, and an elastic modulus of about 4.45 g / cm³. 3 The density and hardness (43 HRC) based on Rockwell hardness grade C are shown. In a particular embodiment, 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%.

[0265] In some embodiments, the striking face and / or cup with the face portion can be cast from Ti-8Al-2.5Mo-2Cr-1V-0.5Fe. In some embodiments, the striking surface and the clubhead body can be integrally formed or cast together from Ti-8Al-2.5Mo-2Cr-1V-0.5Fe, depending on the specific properties required.

[0266] Compared to other existing titanium alloys, the mechanical parameters of Ti-8Al-2.5Mo-2Cr-1V-0.5Fe given above offer surprisingly superior performance. For example, due to the relatively high tensile strength of Ti-8Al-2.5Mo-2Cr-1V-0.5Fe, cast strike surfaces containing this alloy exhibit less deflection per unit thickness when hitting a golf ball compared to other alloys. This is particularly beneficial for metal wood clubs configured for high-speed impacts, as the higher tensile strength of Ti-8Al-2.5Mo-2Cr-1V-0.5Fe results in less deflection of the strike surface and reduces the tendency for the strike surface to flatten with repeated use. This allows the strike surface to retain its original bulge, hump, and "torsion" dimensions over extended periods of use, including by advanced and / or professional golfers who tend to hit the ball at exceptionally high club speeds.

[0267] Any of the embodiments disclosed herein may include a face portion having a distorted striking surface such that the upper toe portion of the striking surface is more open than the lower toe portion of the striking surface, and the lower heel portion of the striking surface is more closed than the upper heel portion of the striking surface. Further information regarding golf club heads with distorted striking surfaces can be found in U.S. Patent 9,814,944; U.S. Provisional Patent 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 incorporated herein by reference in their entirety. Any of these distorted face techniques disclosed in these incorporated references may be implemented in any combination with the techniques disclosed herein in the golf club heads disclosed herein.

[0268] The techniques disclosed herein can be implemented for any type of golf club head, not just the examples disclosed, including drivers, fairway woods, hybrids, multi-purpose clubs, irons, wedges, and putters.

[0269] For the purposes of this specification, certain aspects, advantages, and novel features of embodiments of this disclosure are described herein. The disclosed methods, apparatus, and systems should not be construed as limiting in any way. Rather, this disclosure relates to all novel and non-obvious features and aspects of the various disclosed embodiments, which are individual and present in different combinations and sub-combinations with each other. The methods, apparatus, and systems are not limited to any particular aspect or feature or combination thereof, nor are the disclosed embodiments required to have any one or more specific advantages or to solve any one or more specific problems.

[0270] Although the operations of some embodiments of the disclosed embodiments have been described in a specific, sequential order for ease of presentation, it should be understood that this descriptive approach includes rearrangement unless the specific language of the text requires a particular order. For example, the operations described sequentially may be rearranged or performed simultaneously in certain circumstances. Furthermore, for simplicity, the accompanying drawings may not show the various ways in which the disclosed methods can be combined with other methods.

[0271] As used in this application and in the claims, the singular forms “a,” “an,” and “the” include the plural forms unless the context clearly indicates otherwise. Furthermore, the term “include” means “comprise.” Additionally, the terms “connected” and “associated” generally mean an electrical connection or link, an electromagnetic connection or link, and / or a physical (e.g., mechanical or chemical) connection or link, and do not exclude the presence of intermediate elements between connected or associated articles in the absence of specific contrary language.

[0272] In some instances, a value, program, or device may be referred to as “lowest,” “best,” “smallest,” etc. It will be understood that such a description is intended to indicate that a choice can be made among many alternatives, and that this choice is not necessarily better than, less than, or otherwise preferred over other choices.

[0273] In descriptions, certain terms such as "upper," "lower," "upper part," "lower part," "horizontal," "vertical," "left," "right," and similar terms may be used. Where applicable, these terms are used to provide a clear description when dealing with relative relationships. However, these terms are not intended to imply absolute relationships, positions, and / or orientations. For example, regarding an object, the "upper" surface can simply become the "lower" surface by flipping the object. However, it is still the same object.

[0274] Given that the principles of this disclosure can be applied to many possible embodiments, it should be recognized that the illustrated embodiments are merely preferred examples and should not be considered as limiting the scope of this disclosure. It will be apparent that various modifications can be made thereto without departing from the broader spirit and scope of this disclosure as stated. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a limiting sense. Therefore, the scope of this disclosure is at least as broad as the appended claims. Consequently, we claim all rights within the scope of these claims.

Claims

1. A method for manufacturing a golf club head, the method comprising: A cast cup, made of titanium alloy, comprising the entire face portion of the golf club head, a front portion only of the crown portion of the golf club head, a front portion only of the bottom portion of the golf club head, a front portion only of the toe portion of the golf club head, a front portion only of the heel portion of the golf club head, and a sheath, such that an α-shell is formed on the rear surface of the face portion; as well as The rear surface of the facial portion is machined to remove at least a portion of the α-shell from the rear surface of the facial portion.

2. The method according to claim 1, further comprising: The ring is formed separately from the step of casting the cup; as well as The ring is attached to the cup such that the ring defines the outermost perimeter of the rear portion of the golf club head; The step of machining the rear surface of the facial portion occurs before the step of attaching the ring to the cup.

3. The method of claim 2, wherein the ring is formed of a metallic material different from the titanium alloy of the cup.

4. The method according to claim 2, further comprising: A crown insert made of composite material is attached to the front portion of the crown of the golf club head, which is defined by the ring and the cup; as well as A bottom insert made of composite material is attached to the front portion of the bottom of the golf club head, which is defined by the ring and the cup.

5. The method of claim 1, wherein at least a portion of the α-shell is removed from the rear surface of the face portion without chemically etching the rear surface of the face portion.

6. The method according to claim 1, wherein: The step of casting the cup results in the formation of an α-shell layer on the front surface of the face portion, opposite to the rear surface; and The method further includes machining the front surface of the facial portion to remove at least a portion of the α-shell from the front surface of the facial portion.

7. A golf club head, comprising: A cup having a single integral body made of titanium alloy and comprising the entire face portion of the golf club head, a front portion only of the crown of the golf club head, a front portion only of the bottom of the golf club head, a front portion only of the toe of the golf club head, a front portion only of the heel of the golf club head, and a sheath, wherein the rear surface of the face portion of the golf club head defined by the cup is a machined surface; A ring, attached to the cup and defining the outermost perimeter of the rear portion of the golf club head; and A crown insert, the crown insert being made of a composite material and attached to the front portion of the crown of the golf club head defined by the ring and the cup.

8. The golf club head of claim 7, wherein the ring is made of a metal material different from the titanium alloy of the cup.

9. The golf club head according to claim 7, wherein: The cup also includes a flange formed in the front portion of the crown of the golf club head defined by the cup; and The crown insert is received on the flange, such that the flange is positioned inside the crown insert.

10. The golf club head of claim 7, further comprising a bottom insert made of a composite material and attached to the front portion of the bottom of the golf club head defined by the ring and the cup.

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