The present application concerns golf club heads, and more particularly, golf club heads for wood-type clubs.
In addition to the incorporations discussed further herein, other patents and patent applications concerning golf clubs, such as U.S. Pat. Nos. 7,753,806; 7,887,434; 8,118,689; 8,663,029; 8,888,607; 8,900,069; 9,186,560; 9,211,447; 9,220,953; 9,220,956; 9,848,405; and 9,700,763 and U.S. patent application Ser. No. 15/859,071, are incorporated herein by reference in their entireties.
Much of the recent improvement activity in the field of golf has involved the use of new and increasingly more sophisticated materials in concert with advanced club-head engineering. For example, modern “wood-type” golf clubs (notably, “drivers,” “fairway woods,” and “utility or hybrid clubs”), with their sophisticated shafts and non-wooden club-heads, bear little resemblance to the “wood” drivers, low-loft long-irons, and higher numbered fairway woods used years ago. These modern wood-type clubs are generally called “metalwoods” since they tend to be made primarily of strong, lightweight metals, such as titanium.
An example metalwood golf club such as a driver or fairway wood typically includes a hollow shaft having a lower end to which the golf club head is attached. Most modern versions of these golf club heads are made, at least in part, of a lightweight but strong metal such as titanium alloy. In many cases, the golf club head comprises a body made primarily of such strong metals.
Some current approaches to reducing structural mass of a metalwood club-head are directed to making one or more portions of the golf club head of an alternative material. Whereas the bodies and face plates of most current metalwoods are made of titanium alloys, some golf club heads are made, at least in part, of components formed from either graphite/epoxy-composite (or other suitable composite material) and a metal alloy. Graphite composites have a much lower density compared to titanium alloys, which offers an opportunity to provide more discretionary mass in the club-head.
The ability to utilize such materials to increase the discretionary mass available for placement at various points in the club-head allows for optimization of a number of physical properties of the club-head which can greatly impact the performance obtained by the user. Forgiveness on a golf shot is generally maximized by configuring the golf club head such that the center of gravity (“CG”) of the golf club head is optimally located and the moment of inertia (“MOI”) of the golf club head is maximized. CG and MOI can also critically affect a golf club head's performance, such as launch angle and flight trajectory on impact with a golf ball, among other characteristics.
In addition to the use of various materials to optimize the strength-to-weight properties and acoustic properties of the golf club heads, advances have been made in the mass distribution properties provided by using thicker and thinner regions of materials, raising and lowering certain portions of the sole and crown, providing adjustable weight members and adjustable head-shaft connection assemblies, and many other golf club head engineering advances.
This application discloses, among other innovations, wood-type golf club heads that provide, among other attributes, improved forgiveness, ball speed, adjustability and playability, while maintaining durability.
The following describes wood-type golf club heads that include a body having a bottom portion, a top portion, a front portion, a rear portion, a heel portion, and a toe portion, a sole located on the bottom portion of the golf club head, a crown located at the top portion of the golf club head; and a striking surface positioned at the front portion of the body and configured to receive an impact, the striking surface having a striking surface area measured in square millimeters (mm2). In certain embodiments, the body has a volume of at least 390 cubic centimeters (cc). In particular embodiments, the body has a volume of at least 420 cubic centimeters (cc).
Certain of the golf club heads may have a head origin defined as a position on the face plane at a geometric center of the face, the head origin including an x-axis tangential to the face and generally parallel to the ground when the head is in an address position where a positive x-axis extends towards the heel portion, a y-axis extending perpendicular to the x-axis and generally parallel to the ground when the head is in the address position where a positive y-axis extends from the face and through the rearward portion of the body, and a z-axis extending perpendicular to the ground, to the x-axis and to the y-axis when the head is in the address position where a positive z-axis extends from the head origin and generally upward, wherein the golf club head has a center of gravity.
In certain instances the golf club head may comprise a center sole portion extending from a position proximate the golf club head center of gravity to the rear portion of the body, the center sole portion comprising: a planar surface extending rearwardly and toewardly along the bottom portion of the sole in a generally Y-direction; a toeward sole surface that slopes upwardly from the planar surface when viewed in the address position; a first edge extending in a generally Y-direction on a toe side of the planar surface and defining a transition between the planar surface and the toeward sole surface; a heelward sole surface that slopes upwardly from the planar surface when viewed in the address position; and a second edge extending in a generally Y-direction on a heel side of the planar surface and defining a transition between the planar surface and the heelward sole surface. In particular instances, a surface area to volume ratio calculated by converting the striking surface area into square centimeters (cm2) and dividing by the volume of the golf club head body is no less than 0.06 and no greater than 0.086.
In some instances, the golf club head may comprise a center sole portion extending from a position proximate the golf club head center of gravity to the rear portion of the body, the center sole portion comprising: a planar surface extending rearwardly and toewardly along the bottom portion of the sole in a generally Y-direction; a toeward sole surface that slopes upwardly from the planar surface when viewed in the address position; a first edge extending in a generally Y-direction on a toe side of the planar surface and defining a transition between the planar surface and the toeward sole surface; a heelward sole surface that slopes upwardly from the planar surface when viewed in the address position; and a second edge extending in a generally Y-direction on a heel side of the planar surface and defining a transition between the planar surface and the heelward sole surface; a weight channel formed in the sole and defining a path along the sole; and a weight assembly positioned in the weight channel, the weight assembly configured to be adjusted along the path to any of a range of selectable positions in the weight channel to adjust mass properties of the golf club head. In particular instances, a surface area to volume ratio calculated by converting the striking surface area into square centimeters (cm2) and dividing by the volume of the golf club head body is no less than 0.06 and no greater than 0.086.
In still other instances, the golf club head may comprise a center sole portion extending from a position proximate the golf club head center of gravity to the rear portion of the body, the center sole portion comprising: a planar surface extending rearwardly and toewardly along the bottom portion of the sole in a generally Y-direction; a toeward sole surface that slopes upwardly from the planar surface when viewed in the address position; a first edge extending in a generally Y-direction on a toe side of the planar surface and defining a transition between the planar surface and the toeward sole surface; a heelward sole surface that slopes upwardly from the planar surface when viewed in the address position; and a second edge extending in a generally Y-direction on a heel side of the planar surface and defining a transition between the planar surface and the heelward sole surface. In particular instances, a surface area to volume ratio calculated by converting the striking surface area into square centimeters (cm2) and dividing by the volume of the golf club head body is no less than 0.075 and no greater than 0.084. In certain instances the golf club head has: a volume below 30 mm above ground plane that is at least 45 percent of the body volume, a rear volume that is at least 33 percent of the body volume, a toe volume that is at least 60 percent of the body volume, and a Zup that is no more than 26 mm.
The foregoing and other objects, features, and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
The following disclosure describes embodiments of golf club heads for wood-type clubs (e.g., drivers) that incorporate higher loft angles, lower centers of gravity, or both higher loft angles and lower centers of gravity relative to conventional wood-type clubs. The disclosed embodiments should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and subcombinations with one another. Furthermore, any features or aspects of the disclosed embodiments can be used in various combinations and subcombinations with one another. As used herein, the phrase “and/or” means “and,” “or” and both “and” and “or.” As used herein, the singular forms “a,” “an” and “the” refer to one or more than one, unless the context clearly dictates otherwise. As used herein, the terms “including” and “having” (and their grammatical variants) mean “comprising.” The disclosed embodiments are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved.
Several of the golf club heads incorporate features that provide the golf club heads and/or golf clubs with increased moments of inertia and low centers of gravity, centers of gravity located in preferable locations, improved golf club head and face geometries, increased sole and lower face flexibility, higher coefficients or restitution (“COR”) and characteristic times (“CT”), and/or decreased backspin rates relative to driver and other golf club heads that have come before.
The present disclosure makes reference to the accompanying drawings which form a part hereof. 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. Directions and references may be used to facilitate discussion of the drawings but are not intended to be limiting. For example, certain terms may be used such as “up,” “down,” “upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” and the like. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships, particularly with respect to the illustrated embodiments. Such terms are not, however, intended to imply absolute relationships, positions, and/or orientations, unless otherwise indicated. For example, with respect to an object, an “upper” surface can become a “lower” surface simply by turning the object over. Nevertheless, it is still the same object. Accordingly, the following detailed description shall not be construed in a limiting sense and the scope of property rights sought shall be defined by the appended claims and their equivalents.
Additionally, this disclosure may use terms such as “raised,” “lowered,” “recessed,” “dropped,” etc., which are relative terms depending on perspective. For example, a ground contact surface on the sole of a golf club head could be considered “raised” relative to an indented portion of the sole of the golf club head when the head is upside down with the sole facing upward. On the other hand, the same ground contact surface could also be considered a “dropped sole” part of the sole, since it is located closer to the ground relative to the indented portion when the golf club head is in a normal address position (as further described herein) with the sole facing the ground.
Accordingly, the following detailed description shall not to be construed in a limiting sense.
Golf club head “forgiveness” generally describes the ability of a golf club head to deliver a desirable golf ball trajectory despite a miss-hit (e.g., a ball struck at a location on the face plate other than an ideal impact location, e.g., an impact location where coefficient of restitution is maximized). Large mass moments of inertia contribute to the overall forgiveness of a golf club head. In addition, a low center-of-gravity improves forgiveness for golf club heads used to strike a ball from the turf by giving a higher launch angle and a lower spin trajectory (which improves the distance of a fairway wood golf shot). Providing a rearward center-of-gravity reduces the likelihood of a slice or fade for many golfers. Accordingly, forgiveness of fairway wood golf club heads, can be improved using the techniques described above to achieve high moments of inertia and low center-of-gravity compared to conventional fairway wood golf club heads.
For example, a golf club head with a crown thickness less than about 0.65 mm throughout at least about 70% of the crown can provide significant discretionary mass. A 0.60 mm thick crown formed from steel can provide as much as about 8 grams of discretionary mass compared to a 0.80 mm thick crown. Alternatively, a 0.80 mm thick crown formed from a composite material having a density of about 1.5 g/cc can provide as much as about 26 grams of discretionary mass compared to a 0.80 mm thick crown formed from steel. The large discretionary mass can be distributed to improve the mass moments of inertia and desirably locate the golf club head center-of-gravity. Generally, discretionary mass should be located sole-ward rather than crown-ward to maintain a low center-of-gravity, forward rather than rearward to maintain a forwardly positioned center of gravity, and rearward rather than forward to maintain a rearwardly positioned center-of-gravity. In addition, discretionary mass should be located far from the center-of-gravity and near the perimeter of the golf club head to maintain high mass moments of inertia.
Another parameter that contributes to the forgiveness and successful playability and desirable performance of a golf club is the coefficient of restitution (COR) of the golf club head. Upon impact with a golf ball, the golf club head's face plate deflects and rebounds, thereby imparting energy to the struck golf ball. The golf club head's coefficient of restitution is the ratio of the velocity of separation to the velocity of approach. A thin face plate generally will deflect more than a thick face plate. Thus, a properly constructed club with a thin, flexible face plate can impart a higher initial velocity to a golf ball, which is generally desirable, than a club with a thick, rigid face plate. In order to maximize the moment of inertia (MOI) about the center of gravity (CG) and achieve a high COR, it typically is desirable to incorporate thin walls and a thin face plate into the design of the golf club head. Thin walls afford the designers additional leeway in distributing golf club head mass to achieve desired mass distribution, and a thinner face plate may provide for a relatively higher COR.
Thus, thin walls are important to a club's performance. However, overly thin walls can adversely affect the golf club head's durability. Problems also arise from stresses distributed across the golf club head upon impact with the golf ball, particularly at junctions of golf club head components, such as the junction of the face plate with other golf club head components (e.g., the sole, skirt, and crown). One prior solution has been to provide a reinforced periphery about the face plate, such as by welding, in order to withstand the repeated impacts. Another approach to combat stresses at impact is to use one or more ribs extending substantially from the crown to the sole vertically, and in some instances extending from the toe to the heel horizontally, across an inner surface of the face plate. These approaches tend to adversely affect club performance characteristics, e.g., diminishing the size of the sweet spot, and/or inhibiting design flexibility in both mass distribution and the face structure of the golf club head. Thus, these golf club heads fail to provide optimal MOI, CG, and/or COR parameters, and as a result, fail to provide much forgiveness for off-center hits for all but the most expert golfers.
Thus, the golf club heads of this disclosure are designed to allow for introduction of a face which can be adjusted in thickness as needed or desired to interact with the other disclosed aspects, such as a channel or slot positioned behind the face, as well as increased areas of mass and/or removable weights. The golf club heads of this disclosure may utilize, for example, the variable thickness face features described in U.S. Pat. Nos. 8,353,786, 6,997,820, 6,800,038, and 6,824,475, which are incorporated herein by reference in their entirety. Additionally, the mass of the face, as well as other of the above-described properties can be adjusted by using different face materials, structures, and features, such as those described in U.S. Patent No. RE42,544; U.S. Pat. Nos. 8,096,897; 7,985,146; 7,874,936; 7,874,937; 8,628,434; and 7,267,620; and U.S. Patent Pub. Nos. 2008/0149267 and 2009/0163289, which are herein incorporated by reference in their entirety. Additionally, the structure of the front channel, club head face, and surrounding features of any of the embodiments herein can be varied to further impact COR and related aspects of the golf club head performance, as further described in U.S. Pat. No. 9,662,545 and U.S. Patent Pub. No. 2016/0023062, which are incorporated by reference herein in their entirety.
Club heads and many of their physical characteristics disclosed herein will be described using “normal address position” as the club head reference position, unless otherwise indicated. As used herein, “normal address position” means the club head position wherein a centerface target line vector normal to the club face (or “ball striking surface” or “striking surface”) 118 substantially lies in a first vertical plane 125 (a vertical plane is perpendicular to the ground plane 117), a centerline axis 121 of the club shaft (or “club shaft axis”), substantially lies in a second substantially vertical plane 131 (“shaft plane”), and the first vertical plane and the second substantially vertical plane substantially perpendicularly intersect. The centerface target line vector is defined as a horizontal vector that points forward (along the y-axis) from the center 123. For purposes of this disclosure, the center 123 is also be referred to as the “geometric center” of the ball striking surface 118. See also U.S.G.A. “Procedure for Measuring the Flexibility of a Golf Clubhead,” Revision 2.0 for the methodology to measure the geometric center of the striking face. At normal address position, the club shaft axis 121 defines a lie angle relative to the ground plane such that the scorelines on the face of the club are horizontal. If the club does not have scorelines, then the normal address position lie angle is typically 60-degrees.
A driving-wood-type golf club head, such as the golf club head 100 shown in
A wood-type golf club head, such as golf club head 100 and the other wood-type club heads disclosed herein have a volume, typically measured in cubic-centimeters (cc) equal to the volumetric displacement of the club head, assuming any apertures are sealed by a substantially planar surface. (See United States Golf Association “Procedure for Measuring the Club Head Size of Wood Clubs,” Revision 1.0, Nov. 21, 2003). In other words, for a golf club head with one or more weight ports or other indentations or cavities within the head, it is assumed that these are either not present or are “covered” by regular, imaginary surfaces, such that the club head volume is not affected by the presence or absence of such ports, indentations or cavities.
In some embodiments, as in the case of a driver (as in the illustrated embodiments), any of the disclosed golf club heads can have a volume between about 300 cm3 and about 600 cm3, between about 350 cm3 and about 600 cm3, and/or between about 350 cm3 and about 500 cm3, and can have a total mass between about 145 g and about 260 g, such as between about 195 g and about 205 g. In the case of a fairway wood (which may be analogous to the illustrated embodiments), the golf club head may have a volume between about 100 cm3 and about 300 cm3, such as between about 150 cm3 and about 250 cm3, or between about 130 cm3 and about 190 cm3, or between about 125 cm3 and about 240 cm3, and a total mass between about 125 g and about 260 g, or between about 200 g and about 250 g. In the case of a utility or hybrid club (which may also be analogous to the illustrated embodiments), the golf club head may have a volume between about 60 cm3 and about 150 cm3, or between about 85 cm3 and about 120 cm3, and a total mass between about 125 g and about 280 g, or between about 200 g and about 250 g.
As used herein, “crown” means an upper portion of the club head above a peripheral outline 134 of the club head as viewed from a top-down direction and rearward of the topmost portion of the ball striking surface 118. As used herein, “sole” means a lower portion of the club head 100 extending upwards from a lowest point of the club head when the club head is at the normal address position. In some implementations, the sole 114 extends approximately 50% to 60% of the distance from the lowest point of the club head to the crown 112. In other implementations, the sole 114 extends upwardly from the lowest point of the golf club head 110 a shorter distance. Further, the sole 114 can define a substantially flat portion extending substantially horizontally relative to the ground plane 117 when in normal address position or can have an arced or convex shape as shown in
The body 110, or any parts thereof, can be made from a metal alloy (e.g., an alloy of titanium, an alloy of steel, an alloy of aluminum, and/or an alloy of magnesium), a composite material (e.g., a graphite or carbon fiber composite) a ceramic material, or any combination thereof. The crown 112, sole 114, skirt 116, and ball striking club face 118 can be integrally formed using techniques such as molding, cold forming, casting, and/or forging. Alternatively, any one or more of the crown 112, sole 114, skirt 116, or ball striking club face 118 can be attached to the other components by known means (e.g., adhesive bonding, welding, and the like).
In some embodiments, the striking face 118 is made of a composite material, while in other embodiments, the striking face 118 is made from a metal alloy (e.g., an alloy of titanium, steel, aluminum, and/or magnesium), ceramic material, or a combination of composite, metal alloy, and/or ceramic materials.
When at normal address position, the club head 100 is disposed at a lie angle 119 relative to the club shaft axis (as shown in
Referring to
The head origin coordinate system defined with respect to the head origin 160 includes three axes: a z-axis 162 extending through the head origin 160 in a generally vertical direction relative to the ground plane 117 when the club head 100 is at the normal address position; an x-axis 165 extending through the head origin 160 in a toe-to-heel direction generally parallel to the striking surface 118 (e.g., generally tangential to the striking surface 118 at the center 123) and generally perpendicular to the z-axis 162; and a y-axis 168 extending through the head origin 160 in a front-to-back direction and generally perpendicular to the x-axis 165 and to the z-axis 162. The x-axis 165 and the y-axis 168 both extend in generally horizontal directions relative to the ground plane 117 when the club head 100 is at the normal address position. The x-axis 165 extends in a positive direction from the origin 160 towards the heel 126 of the club head 100. The y-axis 168 extends in a positive direction from the head origin 160 towards the rear portion 132 of the club head 100. The z-axis 162 extends in a positive direction from the origin 160 towards the crown 112.
Generally, the center of gravity (CG) of a golf club head is the average location of the weight of the golf club head or the point at which the entire weight of the golf club head may be considered as concentrated so that if supported at this point the head would remain in equilibrium in any position.
Referring to
Similarly, as illustrated in
CG
eff
=CG
y×Δz
With this formula, the smaller the CGeff, the more effective the club head is at relocating mass low and forward. This measurement adequately describes the location of the CG within the golf club head without projecting the CG onto the face. As such, it allows for the comparison of golf club heads that may have different lofts, different face heights, and different locations of the CF.
The CG can also be used to define a coordinate system with the CG as the origin of the coordinate system. For example, and as illustrated in
As best shown in
Further as used herein, Delta 1 is a measure of how far rearward in the golf club head body the CG is located. More specifically, Delta 1 is the distance between the CG and the hosel axis along the y axis (in the direction straight toward the back of the body of the golf club face from the geometric center of the striking face). It has been observed that smaller values of Delta 1 result in lower projected CGs on the golf club head face. Thus, for embodiments of the disclosed golf club heads in which the projected CG on the ball striking club face is lower than the geometric center, reducing Delta 1 can lower the projected CG and increase the distance between the geometric center and the projected CG. Note also that a lower projected CG can promote a higher launch and a reduction in backspin due to the z-axis gear effect. Thus, for particular embodiments of the disclosed golf club heads, in some cases the Delta 1 values are relatively low, thereby reducing the amount of backspin on the golf ball helping the golf ball obtain the desired high launch, low spin trajectory.
Similarly, Delta 2 is the distance between the CG and the hosel axis along the x axis (in the direction straight toward the back of the body of the golf club face from the geometric center of the striking face).
Adjusting the location of the discretionary mass in a golf club head as described herein can provide the desired Delta 1 value. For instance, Delta 1 can be manipulated by varying the mass in front of the CG (closer to the face) with respect to the mass behind the CG. That is, by increasing the mass behind the CG with respect to the mass in front of the CG, Delta 1 can be increased. In a similar manner, by increasing the mass in front of the CG with the respect to the mass behind the CG, Delta 1 can be decreased.
In terms of the MOI of the club-head (i.e., a resistance to twisting) it is typically measured about each of the three main axes of a club-head with the CG as the origin of the coordinate system. These three axes include a CG z-axis extending through the CG in a generally vertical direction relative to the ground when the golf club head is at normal address position; a CG x-axis extending through the CG origin in a toe-to-heel direction generally parallel to the striking surface (e.g., generally tangential to the striking surface at the club face center), and generally perpendicular to the CG z-axis; and a CG y-axis extending through the CG origin in a front-to-back direction and generally perpendicular to the CG x-axis and to the CG z-axis. The CG x-axis and the CG y-axis both extend in generally horizontal directions relative to the ground when the golf club head is at normal address position. The CG x-axis extends in a positive direction from the CG origin to the heel of the golf club head. The CG y-axis extends in a positive direction from the CG origin towards the rear portion of the golf club head. The CG z-axis extends in a positive direction from the CG origin towards the crown. Thus, the axes of the CG origin coordinate system are parallel to corresponding axes of the head origin coordinate system. In particular, the CG z-axis is parallel to the z-axis, the CG x-axis is parallel to the x-axis, and CG y-axis is parallel to the y-axis.
Specifically, a golf club head has a moment of inertia about the vertical CG z-axis (“Izz”), a moment of inertia about the heel/toe CG x-axis (“Ixx”), and a moment of inertia about the front/back CG y-axis (“Iyy”). Typically, however, the MOI about the CG z-axis (Izz) and the CG x-axis (Ixx) is most relevant to golf club head forgiveness.
A moment of inertia about the golf club head CG x-axis (Ixx) is calculated by the following Equation 1:
where y is the distance from a golf club head CG xz-plane to an infinitesimal mass dm and z is the distance from a golf club head CG xy-plane to the infinitesimal mass dm. The golf club head CG xz-plane is a plane defined by the golf club head CG x-axis and the golf club head CG z-axis. The CG xy-plane is a plane defined by the golf club head CGx-axis and the golf club head CG y-axis.
Similarly, a moment of inertia about the golf club head CG z-axis (Izz) is calculated by the following Equation 2:
where x is the distance from a golf club head CG yz-plane to an infinitesimal mass dm and y is the distance from the golf club head CG xz-plane to the infinitesimal mass dm. The golf club head CG yz-plane is a plane defined by the golf club head CG y-axis and the golf club head CG z-axis.
A further description of the coordinate systems for determining CG positions and MOI can be found in U.S. Pat. No. 9,358,430, the entire contents of which are incorporated by reference herein.
As described herein, desired golf club head mass moments of inertia, golf club head center-of-gravity locations, and other mass properties of a golf club head can be attained by distributing golf club head mass to particular locations. Discretionary mass generally refers to the mass of material that can be removed from various structures providing mass that can be distributed elsewhere for tuning one or more mass moments of inertia and/or locating the golf club head center-of-gravity.
Golf club head walls provide one source of discretionary mass. In other words, a reduction in wall thickness reduces the wall mass and provides mass that can be distributed elsewhere. Thin walls, particularly a thin crown, provide significant discretionary mass compared to conventional golf club heads. For example, a golf club head made from an alloy of steel can achieve about 4 grams of discretionary mass for each 0.1 mm reduction in average crown thickness. Similarly, a golf club head made from an alloy of titanium can achieve about 2.5 grams of discretionary mass for each 0.1 mm reduction in average crown thickness. Discretionary mass achieved using a thin crown, e.g., less than about 0.65 mm, can be used to tune one or more mass moments of inertia and/or center-of-gravity location.
To achieve a thin wall on a golf club head body, such as a thin crown, a golf club head body can be formed from an alloy of steel or an alloy of titanium.
Some examples of titanium alloys that can be used to form any of the striking faces and/or club heads described herein can comprise titanium, aluminum, molybdenum, chromium, vanadium, and/or iron. For example, in one representative embodiment the alloy may be an alpha-beta titanium alloy comprising 6.5% to 10% Al by weight, 0.5% to 3.25% 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 comprising Ti (one example is sometimes referred to as “1300” titanium alloy).
In another representative embodiment, the alloy may comprise 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 comprising Ti.
In another representative embodiment, the alloy may comprise 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 comprising Ti.
In another representative embodiment, the alloy may comprise 7.5% to 8.5% Al by weight, 2.0% to 3.0% Mo by weight, 1.5% to 2.5% Cr by weight, 0.75% to 1.25% V by weight, and/or 0.375% to 0.625% Fe by weight, with the balance comprising Ti.
In another representative embodiment, the alloy may comprise 8% Al by weight, 2.5% Mo by weight, 2% Cr by weight, 1% V by weight, and/or 0.5% Fe by weight, with the balance comprising Ti. Such titanium alloys can have the formula Ti-8Al-2.5Mo-2Cr-1V-0.5Fe. As used herein, reference to “Ti-8Al-2.5Mo-2Cr-1V-0.5Fe” refers to a titanium alloy including the referenced elements in any of the proportions given above. Certain embodiments may also comprise trace quantities of K, Mn, and/or Zr, and/or various impurities.
Ti-8Al-2.5Mo-2Cr-1V-0.5Fe can have minimum mechanical properties of 1150 MPa yield strength, 1180 MPa ultimate tensile strength, and 8% elongation. These minimum properties can be significantly superior to other cast titanium alloys, including 6-4 Ti and 9-1-1 Ti, which can have the minimum mechanical properties noted above. In some embodiments, Ti-8Al-2.5Mo-2Cr-1V-0.5Fe can have a tensile strength of from about 1180 MPa to about 1460 MPa, a yield strength of from about 1150 MPa to about 1415 MPa, an elongation of from about 8% to about 12%, a modulus of elasticity of about 110 GPa, a density of about 4.45 g/cm3, and a hardness of about 43 on the Rockwell C scale (43 HRC). In particular embodiments, the Ti-8Al-2.5Mo-2Cr-1V-0.5Fe alloy can have a tensile strength of about 1320 MPa, a yield strength of about 1284 MPa, and an elongation of about 10%.
In some embodiments, striking faces and/or club head bodies can be cast from Ti-8Al-2.5Mo-2Cr-1V-0.5Fe. In some embodiments, striking surfaces and club head bodies can be integrally formed or cast together from Ti-8Al-2.5Mo-2Cr-1V-0.5Fe, depending upon the particular characteristics desired.
The mechanical parameters of Ti-8Al-2.5Mo-2Cr-1V-0.5Fe given above can provide surprisingly superior performance compared to other existing titanium alloys. For example, due to the relatively high tensile strength of Ti-8Al-2.5Mo-2Cr-1V-0.5Fe, cast striking faces comprising this alloy can exhibit less deflection per unit thickness compared to other alloys when striking a golf ball. This can be especially beneficial for metalwood-type clubs configured for striking a ball at high speed, as the higher tensile strength of Ti-8Al-2.5Mo-2Cr-1V-0.5Fe results in less deflection of the striking face, and reduces the tendency of the striking face to flatten with repeated use. This allows the striking face to retain its original bulge, roll, and “twist” dimensions over prolonged use, including by advanced and/or professional golfers who tend to strike the ball at particularly high club velocities.
For further details concerning titanium casting, please refer to U.S. Pat. No. 7,513,296, incorporated herein by reference.
Additionally, the thickness of a club hosel may be varied to provide for additional discretionary mass, as described in U.S. Pat. No. 9,731,176, the entire contents of which are hereby incorporated by reference.
Various approaches can be used for positioning discretionary mass within a golf club head. For example, golf club heads may have one or more integral mass pads cast into the head at predetermined locations that can be used to lower, to move forward, to move rearward, or otherwise to adjust the location of the golf club head's center-of-gravity, as further described herein. Also, epoxy can be added to the interior of the golf club head, such as through an epoxy port 115 (illustrated in
Alternatively, weights can be attached in a manner which allows adjustment of certain mass properties of the golf club head. For example,
In certain embodiments disclosed herein, the projected CG point on the ball striking club face is located below the geometric center of the club face. In other words, the projected CG point on the ball striking club face is closer to the sole of the club face than the geometric center. As a result, and as illustrated in
The composite crown and/or sole inserts disclosed in various embodiments herein, can help overcome manufacturing challenges associated with conventional golf club heads having normal continuous crowns made of titanium or other metals, and can replace a relatively heavy component of the crown with a lighter material, freeing up discretionary mass which can be strategically allocated elsewhere within the golf club head. In certain embodiments, the crown may comprise a composite material, such as those described herein and in the incorporated disclosures, such as a composite material having a density of less than 2 grams per cubic centimeter. In still further embodiments, the material has a density of no more than 1.5 grams per cubic centimeter, or a density between 1 gram per cubic centimeter and 2 grams per cubic centimeter. Providing a lighter crown further provides the golf club head with additional discretionary mass, which can be used elsewhere within the golf club head to serve the purposes of the designer. For example, with the discretionary mass, additional ribs 192 can be strategically added to the hollow interior of the golf club head and thereby improve the acoustic properties of the head. Discretionary mass in the form of ribs, mass pads or other features also can be strategically located in the interior, or even on the exterior of the golf club head to shift the effective CG fore or aft, toeward or heelward or both (apart from any further CG adjustments made possible by adjustable weight features) or to improve desirable MOI characteristics, as further described herein.
Methods of making any of the golf club heads disclosed herein, or associated golf clubs, may include one or more of the following steps:
The bodies of the golf club heads disclosed herein, and optionally other components of the club heads as well, serve as frames and may be made from a variety of different types of suitable materials. In some embodiments, for example, the body and/or other head components can be made of a metal material such as steel and steel alloys, a titanium or titanium alloy (including but not limited to 6-4 titanium, 3-2.5, 6-4, SP700, 15-3-3-3, 10-2-3, or other alpha/near alpha, alpha-beta, and beta/near beta titanium alloys), or aluminum and aluminum alloys (including but not limited to 3000 series alloys, 5000 series alloys, 6000 series alloys, such as 6061-T6, and 7000 series alloys, such as 7075). The body may be formed by conventional casting, metal stamping or other known processes. The body also may be made of other metals as well as non-metals. The body can provide a framework or skeleton for the club head to strengthen the club head in areas of high stress caused by the golf ball's impact with the face, such as the transition region where the club head transitions from the face to the crown area, sole area and skirt area located between the sole and crown areas.
In some embodiments, the sole insert and/or crown insert of the club head may be made from a variety of composite materials and/or polymeric materials, such as from a thermoplastic material, preferably from a thermoplastic composite laminate material, and most preferably from a thermoplastic carbon composite laminate material. For example, the composite material may comprise an injection moldable material, thermoformable material, thermoset composite material or other composite material suitable for golf club head applications. One example material is a thermoplastic continuous carbon fiber composite laminate material having long, aligned carbon fibers in a PPS (polyphenylene sulfide) matrix or base. One commercial example of this type of material, which is manufactured in sheet form, is TEPEX® DYNALITE 207 manufactured by Lanxess.
TEPEX® DYNALITE 207 is a high strength, lightweight material having multiple layers of continuous carbon fiber reinforcement in a PPS thermoplastic matrix or polymer to embed the fibers. The material may have a 54% fiber volume but other volumes (such as a volume of 42% to 57%) will suffice. The material weighs about 200 g/m2.
Another similar example material which may be used for the crown insert and/or sole insert is TEPEX® DYNALITE 208. This material also has a carbon fiber volume range of 42% to 57%, including a 45% volume in one example, and a weight of 200 g/m2. DYNALITE 208 differs from DYNALITE 207 in that it has a TPU (thermoplastic polyurethane) matrix or base rather than a polyphenylene sulfide (PPS) matrix.
By way of example, the TEPEX® DYNALITE 207 sheet(s) (or other selected material such as DYNALITE 208) are oriented in different directions, placed in a two-piece (male/female) matched die, heated past the melt temperature, and formed to shape when the die is closed. This process may be referred to as thermoforming and is especially well-suited for forming sole and crown inserts.
Once the crown insert and/or sole insert are formed (separately) by the thermoforming process just described, each is cooled and removed from the matched die. The sole and crown inserts are shown as having a uniform thickness, which lends itself well to the thermoforming process and ease of manufacture. However, the sole and crown inserts may have a variable thickness to strengthen select local areas of the insert by, for example, adding additional plies in select areas to enhance durability, acoustic or other properties in those areas.
A crown insert and/or sole insert can have a complex three-dimensional curvature corresponding generally to the crown and sole shapes of a fairway wood-type club head and specifically to the design specifications and dimensions of the particular head designed by the manufacturer. It will be appreciated that other types of club heads, such as drivers, utility clubs (also known as hybrid clubs), rescue clubs, and the like may be manufactured using one or more of the principles, methods and materials described herein.
In an alternative embodiment, the sole insert and/or crown insert can be made by a process other than thermoforming, such as injection molding or thermosetting. In a thermoset process, the sole insert and/or crown insert may be made from prepreg plies of woven or unidirectional composite fiber fabric (such as carbon fiber) that is preimpregnated with resin and hardener formulations that activate when heated. The prepreg plies are placed in a mold suitable for a thermosetting process, such as a compression mold, e.g., a metal matched compression mold, or a bladder mold, and stacked/oriented with the carbon or other fibers oriented in different directions. The plies are heated to activate the chemical reaction and form the sole (or crown) insert. Each insert is cooled and removed from its respective mold. Additional disclosure regarding methods of forming sole and/or crown inserts can be found in U.S. Pat. No. 9,579,549, the entire contents of which are incorporated by reference.
In some embodiments, a composite material, such as a carbon composite, made of a composite including multiple plies or layers of a fibrous material (e.g., graphite, or carbon fiber including turbostratic or graphitic carbon fiber or a hybrid structure with both graphitic and turbostratic parts present. Examples of some of these composite materials for use in the metalwood golf clubs and their fabrication procedures are described in U.S. Reissue Pat. No. RE41,577; U.S. Pat. Nos. 7,267,620; 7,140,974; 8,096,897; 7,628,712; 7,985,146; 7,874,936; 7,874,937; 8,628,434; and 7,874,938; and U.S. Patent Pub. Nos. 2008/0149267 and 2009/0163289, which are all incorporated herein by reference. The composite material may be manufactured according to the methods described at least in U.S. Patent Pub. No. 2008/0149267, the entire contents of which are herein incorporated by reference.
Alternatively, short or long fiber-reinforced formulations of the previously referenced polymers. Example formulations include a Nylon 6/6 polyamide formulation which is 30% Carbon Fiber Filled and available commercially from RTP Company under the trade name RTP 285. The material has a Tensile Strength of 35000 psi (241 MPa) as measured by ASTM D 638; a Tensile Elongation of 2.0-3.0% as measured by ASTM D 638; a Tensile Modulus of 3.30×106 psi (22754 MPa) as measured by ASTM D 638; a Flexural Strength of 50000 psi (345 MPa) as measured by ASTM D 790; and a Flexural Modulus of 2.60×106 psi (17927 MPa) as measured by ASTM D 790.
Also included is a polyphthalamide (PPA) formulation which is 40% Carbon Fiber Filled and available commercially from RTP Company under the trade name RTP 4087 UP. This material has a Tensile Strength of 360 MPa as measured by ISO 527; a Tensile Elongation of 1.4% as measured by ISO 527; a Tensile Modulus of 41500 MPa as measured by ISO 527; a Flexural Strength of 580 MPa as measured by ISO 178; and a Flexural Modulus of 34500 MPa as measured by ISO 178.
Also included is a polyphenylene sulfide (PPS) formulation which is 30% Carbon Fiber Filled and available commercially from RTP Company under the trade name RTP 1385 UP. This material has a Tensile Strength of 255 MPa as measured by ISO 527; a Tensile Elongation of 1.3% as measured by ISO 527; a Tensile Modulus of 28500 MPa as measured by ISO 527; a Flexural Strength of 385 MPa as measured by ISO 178; and a Flexural Modulus of 23,000 MPa as measured by ISO 178.
An example is a polysulfone (PSU) formulation which is 20% Carbon Fiber Filled and available commercially from RTP Company under the trade name RTP 983. This material has a Tensile Strength of 124 MPa as measured by ISO 527; a Tensile Elongation of 2% as measured by ISO 527; a Tensile Modulus of 11032 MPa as measured by ISO 527; a Flexural Strength of 186 MPa as measured by ISO 178; and a Flexural Modulus of 9653 MPa as measured by ISO 178.
Another example is a polysulfone (PSU) formulation which is 30% Carbon Fiber Filled and available commercially from RTP Company under the trade name RTP 985. This material has a Tensile Strength of 138 MPa as measured by ISO 527; a Tensile Elongation of 1.2% as measured by ISO 527; a Tensile Modulus of 20685 MPa as measured by ISO 527; a Flexural Strength of 193 MPa as measured by ISO 178; and a Flexural Modulus of 12411 MPa as measured by ISO 178.
Also an option is a polysulfone (PSU) formulation which is 40% Carbon Fiber Filled and available commercially from RTP Company under the trade name RTP 987. This material has a Tensile Strength of 155 MPa as measured by ISO 527; a Tensile Elongation of 1% as measured by ISO 527; a Tensile Modulus of 24132 MPa as measured by ISO 527; a Flexural Strength of 241 MPa as measured by ISO 178; and a Flexural Modulus of 19306 MPa as measured by ISO 178.
The foregoing materials are well-suited for composite, polymer and insert components of the embodiments disclosed herein, as distinguished from components which preferably are made of metal or metal alloys.
Additional details regarding providing composite soles and/or crowns and crown layups are provided in U.S. Patent Pub. No. 2016/0001146, the entire contents of which are hereby incorporated by reference.
As described in detail in U.S. Pat. No. 6,623,378, filed Jun. 11, 2001, entitled “METHOD FOR MANUFACTURING AND GOLF CLUB HEAD” and incorporated by reference herein in its entirety, the crown or outer shell of the golf club head 100 may be made of a composite material, such as, for example, a carbon fiber reinforced epoxy, carbon fiber reinforced polymer, or a polymer. Additionally, U.S. Patent Pub. No. 2004/0116207 and U.S. Pat. No. 6,969,326, also incorporated by reference herein in their entirety, describe golf club heads with lightweight crowns. Furthermore, U.S. patent application Ser. No. 12/974,437 (now U.S. Pat. No. 8,608,591), also incorporated by reference herein in its entirety, describes golf club heads with lightweight crowns and soles.
In some embodiments, composite materials used to construct the crown and/or sole insert should exhibit high strength and rigidity over a broad temperature range as well as good wear and abrasion behavior and be resistant to stress cracking. Such properties include (1) a Tensile Strength at room temperature of from about 7 ksi to about 330 ksi, preferably of from about 8 ksi to about 305 ksi, more preferably of from about 200 ksi to about 300 ksi, even more preferably of from about 250 ksi to about 300 ksi (as measured by ASTM D 638 and/or ASTM D 3039); (2) a Tensile Modulus at room temperature of from about 0.4 Msi to about 23 Msi, preferably of from about 0.46 Msi to about 21 Msi, more preferably of from about 0.46 Msi to about 19 Msi (as measured by ASTM D 638 and/or ASTM D 3039); (3) a Flexural Strength at room temperature of from about 13 ksi to about 300 ksi, from about 14 ksi to about 290 ksi, more preferably of from about 50 ksi to about 285 ksi, even more preferably of from about 100 ksi to about 280 ksi (as measured by ASTM D 790); and (4) a Flexural Modulus at room temperature of from about 0.4 Msi to about 21 Msi, from about 0.5 Msi to about 20 Msi, more preferably of from about 10 Msi to about 19 Msi (as measured by ASTM D 790).
In certain embodiments, composite materials that are useful for making club-head components comprise a fiber portion and a resin portion. In general, the resin portion serves as a “matrix” in which the fibers are embedded in a defined manner. In a composite for club-heads, the fiber portion is configured as multiple fibrous layers or plies that are impregnated with the resin component. The fibers in each layer have a respective orientation, which is typically different from one layer to the next and precisely controlled. The usual number of layers for a striking face is substantial, e.g., forty or more. However, for a sole or crown, the number of layers can be substantially decreased to, e.g., three or more, four or more, five or more, six or more, examples of which will be provided below. During fabrication of the composite material, the layers (each comprising respectively oriented fibers impregnated in uncured or partially cured resin; each such layer being called a “prepreg” layer) are placed superposedly in a “lay-up” manner. After forming the prepreg lay-up, the resin is cured to a rigid condition. If interested a specific strength may be calculated by dividing the tensile strength by the density of the material. This is also known as the strength-to-weight ratio or strength/weight ratio.
In tests involving certain club-head configurations, composite portions formed of prepreg plies having a relatively low fiber areal weight (FAW) have been found to provide superior attributes in several areas, such as impact resistance, durability, and overall club performance. FAW is the weight of the fiber portion of a given quantity of prepreg, in units of g/m2. Crown and/or sole panels may be formed of plies of composite material having a fiber areal weight of between 20 g/m2 and 200 g/m2 and a density between about 1 g/cc and 2 g/cc. However, FAW values below 100 g/m2, and more desirably 75 g/m2 or less, can be particularly effective. A particularly suitable fibrous material for use in making prepreg plies is carbon fiber, as noted. More than one fibrous material can be used. In other embodiments, however, prepreg plies having FAW values below 70 g/m2 and above 100 g/m2 may be used. Generally, cost is the primary prohibitive factor in prepreg plies having FAW values below 70 g/m2.
In particular embodiments, multiple low-FAW prepreg plies can be stacked and still have a relatively uniform distribution of fiber across the thickness of the stacked plies. In contrast, at comparable resin-content (R/C, in units of percent) levels, stacked plies of prepreg materials having a higher FAW tend to have more significant resin-rich regions, particularly at the interfaces of adjacent plies, than stacked plies of low-FAW materials. Resin-rich regions tend to reduce the efficacy of the fiber reinforcement, particularly since the force resulting from golf-ball impact is generally transverse to the orientation of the fibers of the fiber reinforcement. The prepreg plies used to form the panels desirably comprise carbon fibers impregnated with a suitable resin, such as epoxy. An example carbon fiber is “34-700” carbon fiber (available from Grafil, Sacramento, Calif.), having a tensile modulus of 234 Gpa (34 Msi) and a tensile strength of 4500 Mpa (650 Ksi). Another Grafil fiber that can be used is “TR50S” carbon fiber, which has a tensile modulus of 240 Gpa (35 Msi) and a tensile strength of 4900 Mpa (710 ksi). Suitable epoxy resins are types “301” and “350” (available from Newport Adhesives and Composites, Irvine, Calif.). An example resin content (R/C) is between 33% and 40%, preferably between 35% and 40%, more preferably between 36% and 38%.
Some of the embodiments of the golf club head 100 discussed throughout this application may include a separate crown, sole, and/or face that may be a composite, such as, for example, a carbon fiber reinforced epoxy, carbon fiber reinforced polymer, or a polymer crown, sole, and/or face. Alternatively, the crown, sole, and/or face may be made from a less dense material, such as, for example, Titanium or Aluminum. A portion of the crown may be cast from either steel (˜7.8-8.05 g/cm3) or titanium (˜4.43 g/cm3) while a majority of the crown may be made from a less dense material, such as for example, a material having a density of about 1.5 g/cm3 or some other material having a density less than about 4.43 g/cm3. In other words, the crown could be some other metal or a composite. Additionally or alternatively, the face may be welded in place rather than cast as part of the sole.
By making the crown, sole, and/or face out of a less dense material, it may allow for weight to be redistributed from the crown, sole, and/or face to other areas of the club head, such as, for example, low and forward and/or low and back. Both low and forward and low and back may be possible for club heads incorporating a front to back sliding weight track.
U.S. Pat. No. 8,163,119 discloses composite articles and methods for making composite articles, which disclosure is incorporated by reference herein in the entirety. U.S. Pat. Nos. 9,452,325 and 7,279,963 disclose various composite crown constructions that may be used for golf club heads, which disclosures are also incorporated by reference herein in their entireties. The techniques and layups described in U.S. Pat. Nos. 8,163,119; 9,452,325; and 7,279,963, incorporated herein by reference in their entirety, may be employed for constructing a composite crown panel, composite sole panel, composite toe panel located on the sole, and/or composite heel panel located on the sole.
U.S. Pat. No. 8,163,119 discloses the usual number of layers for a striking plate is substantial, e.g., fifty or more. However, improvements have been made in the art such that the layers may be decreased to between 30 and 50 layers. Additionally, for a panel located on the sole and/or crown the layers can be substantially decreased down to three, four, five, six, seven, or more layers.
It should be understood that the crown and sole may not have the same thickness or be made from the same materials. In certain embodiments, the sole may be made from either a titanium alloy or a steel alloy. Similarly, the main body of the golf club head may be made from either a titanium alloy or a steel alloy. The titanium will typically range from 0.4 mm to about 0.9 mm, preferably from 0.4 mm to about 0.8 mm, more preferably from 0.4 mm to about 0.7 mm, even more preferably from 0.45 mm to about 0.6 mm. In some instances, the crown and/or sole may have non-uniform thickness, such as, for example varying the thickness between about 0.45 mm and about 0.55 mm.
A lot of discretionary mass may be freed up by using composite material in the crown and/or sole especially when combined with thin walled titanium construction (0.4 mm to 0.9 mm) in other parts of the golf club head. The thin walled titanium construction increases the manufacturing difficulty and ultimately fewer parts are cast at a time. In the past, 100+ golf club heads could be cast at a single time, however due to the thinner wall construction fewer golf club heads are cast per cluster to achieve the desired combination of high yield and low material usage.
An important strategy for obtaining more discretionary mass is to reduce the wall thickness of the golf club head. For a typical titanium-alloy “metal-wood” club-head having a volume of 460 cc (i.e., a driver) and a crown area of 100 cm2, the thickness of the crown is typically about 0.8 mm, and the mass of the crown is about 36 g. Thus, reducing the wall thickness by 0.2 mm (e.g., from 1 mm to 0.8 mm) can yield a discretionary mass “savings” of 9.0 g.
The following examples will help to illustrate the possible discretionary mass “savings” by making a composite crown rather than a titanium-alloy crown. For example, reducing the material thickness to about 0.73 mm yields an additional discretionary mass “savings” of about 25.0 g over a 0.8 mm titanium-alloy crown. For example, reducing the material thickness to about 0.73 mm yields an additional discretionary mass “savings” of about 25 g over a 0.8 mm titanium-alloy crown or 34 g over a 1.0 mm titanium-alloy crown. Additionally, a 0.6 mm composite crown yields an additional discretionary mass “savings” of about 27 g over a 0.8 mm titanium-alloy crown. Moreover, a 0.4 mm composite crown yields an additional discretionary mass “savings” of about 30 g over a 0.8 mm titanium-alloy crown. The crown can be made even thinner yet to achieve even greater weight savings, for example, about 0.32 mm thick, about 0.26 mm thick, about 0.195 mm thick. However, the crown thickness must be balanced with the overall durability of the crown during normal use and misuse. For example, an unprotected crown i.e. one without a head cover could potentially be damaged from colliding with other woods or irons in a golf bag.
For example, any of the embodiments disclosed herein may have a crown or sole insert formed of plies of composite material having a fiber areal weight of between 20 g/m2 and 200 g/m2, preferably between 50 g/m2 and 100 g/m2, the weight of the composite crown being at least 20% less than the weight of a similar sized piece formed of the metal of the body. The composite crown may be formed of at least four plies of uni-tape standard modulus graphite, the plies of uni-tape oriented at any combination of 0° (forward to rearward of the club head), +45°, −45° and 90° (heelward to toeward of the golf club head). Additionally or alternatively, the crown may include an outermost layer of a woven graphite cloth. Carbon crown panels or inserts or carbon sole panels as disclosed herein and in the incorporated applications may be utilized with any of the embodiments herein, and may have a thickness between 0.40 mm to 1.0 mm, preferably 0.40 mm to 0.80 mm, more preferably 0.40 mm to 0.65 mm, and a density between 1 gram per cubic centimeter and 2 grams per cubic centimeter, though other thicknesses and densities are also possible.
One potential embodiment of a carbon sole panel that may be utilized with any of the embodiments herein weighs between 1.0 grams and 5.0 grams, such as between 1.25 grams and 2.75 grams, such as between 3.0 grams and 4.5 grams. In other embodiments, the carbon sole panel may weigh less than 3.0 grams, such as less than 2.5 grams, such as less than 2.0 grams, such as less than 1.75 grams. The carbon sole panel may have a surface area of at least 1250 mm2, 1500 mm2, 1750 mm2, or 2000 mm2.
One potential embodiment of a carbon crown panel that may be utilized with any of the embodiments herein weighs between 3.0 grams and 8.0 grams, such as between 3.5 grams and 7.0 grams, such as between 3.5 grams and 7.0 grams. In other embodiments, the carbon crown panel may weigh less than 7.0 grams, such as less than 6.5 grams, such as less than 6.0 grams, such as less than 5.5 grams, such as less than 5.0 grams, such as less than 4.5 grams.
A driving-wood-type golf club head, such as the golf club head 300 shown in
Golf club head 300 includes a hollow body 310 defining a crown portion 312, a sole portion 314, a skirt portion 316, and a striking surface 318. The striking surface 318 can be integrally formed with the body 310 or attached to the body. The body 310 further includes a hosel 320, which defines a hosel bore 324 adapted to receive a golf club shaft. The body 310 further includes a heel portion 326, a toe portion 328, a front portion 330, and a rear portion 332. Included are a number of features that may improve playability, including at least an inertia generator 360, front channel 390, as well as composite panels on the sole 344, 348 and on the crown 335, along with discretionary mass elements and other additional features, as will be further described herein.
The club head 300 also has a volume, typically measured in cubic-centimeters (cc), equal to the volumetric displacement of the club head, assuming any apertures are sealed by a substantially planar surface. According to some embodiments, the golf club head 300 may have a volume of between 400 and 470 cubic centimeters (cc), such as between 420 cc and 470 cc, or between 440 cc and 470 cc.
The body 310, or any parts thereof, can be made from a metal alloy (e.g., an alloy of titanium, an alloy of steel, an alloy of aluminum, and/or an alloy of magnesium), a composite material (e.g., a graphite or carbon fiber composite) a ceramic material, or any combination thereof. The crown 312, sole 314, skirt 316, and striking surface 318 can be integrally formed using techniques such as molding, cold forming, casting, and/or forging. Alternatively, any one or more of the crown 312, sole 314, skirt 316, or striking surface 318 can be attached to the other components by known means (e.g., adhesive bonding, welding, and the like).
In some embodiments, the striking face 318 is made of a composite material, while in other embodiments, the striking face 318 is made from a metal alloy (e.g., an alloy of titanium, steel, aluminum, and/or magnesium), ceramic material, or a combination of composite, metal alloy, and/or ceramic materials.
As illustrated in
As best illustrated in
In some embodiments, the surface of the crown 312 may comprise one or more surface features, such as a plurality of vortex generators 336, which as illustrated in
As shown in
The center 323 is defined as the intersection of the midpoints of a length (Lss) and a width (Wss) of the striking surface 318. Both Lss and Wss are determined using the striking face curve (Sss), as described above. According to some embodiments, the striking surface may have a width Wss of between 80 mm and 100 mm, such as between 80 mm and 90 mm, or between 85 mm and 90 mm, and a length Lss of between 35 mm and 50 mm, such as between 40 mm and 50 mm, or between 40 mm and 45 mm.
Also illustrated is a striking surface height (or “face height”) Hss, which measures the height above the ground plane 317 of the striking face curve's periphery that is proximate to the crown portion of Sss. According to some embodiments, the striking surface may have a height Hss of between 45 mm and 60 mm, such as between 50 mm and 60 mm, or between 50 mm and 55 mm.
As also described above, the portion of the striking surface 118 bounded by the striking face curve periphery defines a striking surface area (or “face area”), which may be measured to determine playability characteristics of the golf club head. According to some embodiments, the striking surface area may be at least 2900 mm2, such as between 2900 mm2 and 4000 mm2 between 3200 mm2 and 3950, or between 3250 mm2 and 3500 mm2.
Decreasing the face area relative to the overall volume of the golf club head may provide advantageous improvements to the playability of the club, such as its aerodynamics. In order to calculate a ratio between face area and volume, it may first be helpful to convert the face area in mm2 to a measurement in centimeters. So, e.g., an area of 3950 mm2 would be equivalent to an area of 39.5 cm2. Using this measurement to compare face area to overall club head volume (measured in cubic centimeters (cc, or cm3), according to some embodiments, a desirable ratio of face area to overall club head volume might be between no less than 0.06 and no more than 0.086, such as no more than 0.085, no more than 0.084, no more than 0.083, no more than 0.082, or no more than 0.081.
Also shown is a center plane 322 that extends rearward from the geometric center 323 of the golf club head perpendicular to both an origin y-axis (not pictured) and the ground plane 317. According to some embodiments, the golf club head 300 may have a volume toeward of the center plane 322 (“toe volume”) of between 280 and 300 cc, such as at least 280 cc, at least 285 cc, or at least 290 cc. In some embodiments, the ratio of the toe volume of the golf club head to the total volume of the golf club head may be greater than 0.56, such as greater than 0.58, greater than 0.60, greater than 0.62, or greater than 0.63.
Extending perpendicular to the ground plane 317 in
Illustrated in
Also illustrated in
Also illustrated in
In some cases, golf club heads having a taller vertical profile may exhibit improved aerodynamic qualities, but this taller vertical profile may have offsetting negative impacts on the golf club head's center of gravity. In the club heads disclosed herein, the clubs center of gravity is lowered (along the z-axis, toward the ground plane) by placing additional discretionary mass lower in the golf club head. Thus the golf club heads of this disclosure provide advantages both in terms of aerodynamic qualities, which may, for example, allow for greater club head speed at impact, along with a lower center of gravity, which has a number of benefits described herein and in the incorporated patents and applications. Additional information about the center of gravity of the illustrated golf club heads is provided below.
Illustrated in
As described above, Zup represents the distance of the center of gravity above a ground plane 317. According to some advantageous embodiments, club head 300 may have a Zup of less than 32 mm, such as less than 30 mm, less than 28 mm, less than 26 mm, or less than 25 mm.
Illustrated in
In some embodiments, the toe curvature of the golf club head at a distance of between 10 mm and 40 mm above the ground plane at normal address position may be in a range between 20 mm to 60 mm, such as between 35 mm and 50 mm, or between 30 mm and 45 mm. In particular embodiments, the minimum toe curvature of the golf club head may be no less than 20 mm. In still other particular embodiments, the maximum toe curvature of the golf club head may be no greater than 60 mm.
Additionally, a volume of the golf club head 300 between the ground plane 317 and the 30 mm cross section line 305 (“volume below 30 mm above ground plane”) may be at least 190 cc, such as at least 195 cc, at least 200 cc, at least 205 cc, at least 210 cc, at least 215 cc, or at least 220 cc. In some embodiments, the ratio of the volume below 30 mm above ground plane of the golf club head to the total volume of the golf club head may be greater than 0.4, such as greater than 0.42, greater than 0.44, greater than 0.46, or greater than 0.48.
As illustrated in
As best illustrated in
As illustrated in
As best illustrated in
As best illustrated in
The inertia generator is configured so that a center of gravity 365 may in certain embodiments be positioned toeward of the x axis and lower (or closer to the ground plane 317) than the z-axis. In other words, the inertia generator may help to move the club's overall center of gravity 350 toeward, while also lowering its center of gravity, reducing Zup, as described above.
Example values for the inertia generator's center of gravity 365 are set forth below. In certain embodiments, the inertia generator may have a center of gravity 365 relative to the center 323 of the striking surface 318 as measured on the:
Additionally, due to its shape and orientation, the inertia generator is configured to generally align with a typical swing path, permitting increased inertia generated during a golf swing. Example moments of inertia for golf club head 300 are set forth below.
In some embodiments described herein, such as golf club head 300, one or more of the features described herein may contribute to a moment of inertia about a golf club head CG z-axis (Izz) that is greater than 300 kg·mm2, such as greater than 350 kg·mm2, greater than 400 kg·mm2, greater than 450 kg·mm2, or greater than 500 kg·mm2
In some embodiments described herein, such as golf club head 300, a moment of inertia about a golf club head CG x-axis (Ixx) can be greater than 250 kg·mm2, such as greater than 300 kg·mm2, or greater than 350 kg·mm2.
As described above, providing thin walls and/or the use of composite materials may permit the addition of discretionary mass in portions of the golf club head which may be selected to improve playability characteristics of the golf club head. For example, to generate increased inertia, it may be desirable to maximize the mass that is positioned within a given swing path to maximize inertia and/or to maximize mass lower to the ground plane in a golf club head to lower the center of gravity.
1. Front mass pad
As illustrated in
Positioning forward mass pad 380 heelward may help offset the discretionary mass that is positioned toeward in the club, such as in the inertia generator. Additionally, “split mass” configurations such as those described herein potentially allow greater weight to be moved to the outside of the club head while minimizing the overall weight added to the club head.
Providing these spaced apart areas of mass (e.g., the mass pad 380 and inertia generator 360) may both help to maintain the center of gravity of the golf club head as close as possible to the geometric center, while also providing added weight along the perimeter of the golf club, which may have additional benefits for maximizing MOI, as further described herein.
2. Rear removable weight
Positioned on a rear side of the inertia generator 360 is inertia generator mass element 385, which may comprise a steel or tungsten weight member or other suitable material. Inertia generator mass element 385 may be removably affixed to the rear of the inertia generator 360 using a fastener port 386 that is positioned in the rear of the inertia generator 360 and configured to receive a fastener 388, which may be removably inserted through an aperture 387 in the inertia generator mass element 385 and into the fastener port 386. Fastener port 386 and aperture 387 may be threaded so that fastener 388 can be loosened or tightened either to allow movement of, or to secure in position, inertia generator mass element 385. The fastener may comprise a head with which a tool (not shown) may be used to tighten or loosen the fastener, and a body that may, e.g., be threaded to interact with corresponding threads on the fastener port 386 and aperture 387 to facilitate tightening or loosening the fastener 388.
The fastener port 386 can have any of a number of various configurations to receive and/or retain any of a number of fasteners, which may comprise simple threaded fasteners, such as described herein, or which may comprise removable weights or weight assemblies, such as described in U.S. Pat. Nos. 6,773,360, 7,166,040, 7,452,285, 7,628,707, 7,186,190, 7,591,738, 7,963,861, 7,621,823, 7,448,963, 7,568,985, 7,578,753, 7,717,804, 7,717,805, 7,530,904, 7,540,811, 7,407,447, 7,632,194, 7,846,041, 7,419,441, 7,713,142, 7,744,484, 7,223,180, 7,410,425 and 7,410,426, the entire contents of each of which are incorporated by reference herein.
As illustrated in
One potential embodiment of an inertia generator mass element 385 that may be utilized with any of the embodiments herein weighs between 10 grams and 50 grams, such as between 10 grams and 30 grams or between 20 grams and 40 grams.
Near the striking surface 318, a front channel 390 is formed in the sole 314. As illustrated in
As illustrated in
During development, it was discovered that a ratio of COR feature length to the offset distance may be preferably greater than 4, and even more preferably greater than 5, and most preferably greater than 5.5. However, the ratio of COR feature length to offset distance also has an upper limit and is preferably less than 15, and even more preferably less than 14, and most preferably less than 13.5. For example, for a COR feature length of 30 mm the offset distance from the face would preferably be less than 7.5 mm, and even more preferably 6 mm or less from the face. Additional disclosure about the relationship between COR feature length and offset, and related effects are provided in in co-pending U.S. patent application Ser. No. 15/859,071, the entire contents of which are hereby incorporated by reference.
The offset distance is highly dependent on the slot length. As slot length increases so do the stresses in the club head, as a result the offset distance must be increased to manage stress. Additionally, as slot length increases the first mode frequency is negatively impacted.
As illustrated in
The golf club head is removably attached to the shaft by shaft connection assembly 355 (which is mounted to the lower end portion of a golf club shaft (not shown)) by inserting one end of the shaft connection assembly 355 into the hosel bore 324, and inserting a screw 379 (or other suitable fixation device) upwardly through the recessed port 378 in the sole 314 and, in the illustrated embodiment, tightening the screw 379 into a threaded opening of the shaft connection assembly 355, thereby securing the golf club head to the shaft sleeve 302. A screw capturing device, such as in the form of an O-ring or washer 381, can be placed on the shaft of the screw 379 to retain the screw in place within the golf club head when the screw is loosened to permit removal of the shaft from the golf club head.
In the embodiment shown in
Further in certain embodiments, the golf club head may also incorporate features that provide the golf club heads and/or golf clubs with the ability not only to replaceably connect the shaft to the head but also to adjust the loft and/or the lie angle of the club by employing a removable head-shaft connection assembly. Such an adjustable lie/loft connection assembly is described in more detail in U.S. Pat. Nos. 8,025,587; 8,235,831; 8,337,319; 8,758,153; 8,398,503; 8,876,622; 8,496,541; and 9,033,821, the entire contents of which are incorporated in their entirety by reference herein.
In certain embodiments, the golf club head may be attached to the shaft via a removable head-shaft connection assembly as described in more detail in U.S. Pat. No. 8,303,431, the entire contents of which are incorporated by reference herein. As described in more detail therein, inserting a shaft sleeve at different angular positions relative to a hosel insert is effective to adjust the shaft loft and/or the lie angle. For example, the loft angle may be increased or decreased by various degrees, depending on the angular position, such as +/−1.5 degrees, +/−2.0 degrees, or +/−2.5 degrees. Other loft and/or lie angle adjustments are also possible.
A golf club head Characteristic Time (CT) can be described as a numerical characterization of the flexibility of a golf club head striking face. The CT may also vary at points distant from the center of the striking face, but may not vary greater than approximately 20% of the CT as measured at the center of the striking face. The CT values for the golf club heads described in the present application were calculated based on the method outlined in the USGA “Procedure for Measuring the Flexibility of a Golf Clubhead,” Revision 2.0, Mar. 25, 2005, which is incorporated by reference herein in its entirety. Specifically, the method described in the sections entitled “3. Summary of Method,” “5. Testing Apparatus Set-up and Preparation,” “6. Club Preparation and Mounting,” and “7. Club Testing” are example sections that are relevant. Specifically, the characteristic time is the time for the velocity to rise from 5% of a maximum velocity to 95% of the maximum velocity under the test set forth by the USGA as described above.
As best illustrated in
One or more of the golf club heads disclosed herein may also incorporate “twist face” technology, which may provide a striking surface that is “twisted,” to assist, in particular, with “miss-hit” shots that are not impacted at the center of the face. Additional details about providing golf club heads employing “twist face” technology are provided in U.S. Pat. No. 9,814,944, the entire contents are hereby incorporated by reference herein.
Golf club head 400 includes a hollow body 410 defining a crown portion 412, a skirt portion (not shown), a sole portion 414, and a striking surface 418. The striking surface 418 can be integrally formed with the body 410 or attached to the body. The body 410 further includes a hosel 420, which is adapted to receive a golf club shaft. The body 410 further includes a heel portion 426, a toe portion 428, a front portion 430, and a rear portion 432. Included are a number of features that may improve playability, including at least an inertia generator 460, front channel 490, as well as composite panels on the sole 444, 448 and on the crown 435, along with discretionary mass elements, such as a front weight channel 480 in which a front weight assembly 482 may be positioned, and a rear weight channel 470 positioned within the inertia generator 460 into which a rear weight assembly 472 may be inserted, as further described below, and other additional features, as will be further described herein
In the embodiments shown in
As illustrated in
In the embodiments shown in the figures, the channel 480 is substantially straight within the X-Y plane (see, e.g.,
In the embodiments shown, the distance between a first vertical plane passing through the center of the striking surface 418 and a second vertical plane that bisects the channel 480 at the same x-coordinate as the center 423 of the striking surface 418 is between about 15 mm and about 50 mm, such as between about 20 mm and about 40 mm, such as between about 25 mm and about 30 mm. In the embodiments shown, the width of the channel (i.e., the horizontal distance between the front channel wall and rear channel wall adjacent to the locations of front ledge 481 and rear ledge 483) may be between about 8 mm and about 20 mm, such as between about 10 mm and about 18 mm, such as between about 12 mm and about 16 mm. In the embodiments shown, the depth of the channel may be between about 6 mm and about 20 mm, such as between about 6 mm and about 15 mm, such as between about 7 mm and about 14 mm. In the embodiments shown, the length of the channel (i.e., the horizontal distance between the heel end 486 of the channel and the toe end 488 of the channel) may be between about 30 mm and about 120 mm, such as between about 50 mm and about 100 mm, such as between about 60 mm and about 90 mm.
As illustrated in
In the embodiments shown in
Additionally, rear weight assembly 472 may be configured so that it can be removed and positioned within the front channel 480 to provide additional weight forward within the golf club head, as desired.
In the embodiments shown, the width of the channel (i.e., the horizontal distance between the heel channel wall and toe channel wall adjacent to the locations of the heel ledge 471 and toe ledge 473 may be between about 8 mm and about 20 mm, such as between about 10 mm and about 18 mm, such as between about 12 mm and about 16 mm. In the embodiments shown, the depth of the channel may be between about 6 mm and about 20 mm, such as between about 6 mm and about 15 mm, such as between about 7 mm and about 14 mm.
Although the following discussion cites features related to golf club head 400, the many design parameters discussed below substantially apply to the other disclosed golf club heads sharing common features, as described herein. With that in mind, in some embodiments of the golf clubs described herein, the location, position or orientation of features of the golf club head, such as the golf club heads 300, 400, and 500, can be referenced in relation to fixed reference points, e.g., a golf club head origin, other feature locations or feature angular orientations. The location or position of a weight or weight assembly, such as mass pad 380, inertia generator mass element 385, front and rear weight assemblies 482, 472, front weight member 582, and inertia generator mass element 585, is typically defined with respect to the location or position of the weight's or weight assembly's center of gravity. When a weight or weight assembly is used as a reference point from which a distance, i.e., a vectorial distance (defined as the length of a straight line extending from a reference or feature point to another reference or feature point) to another weight or weight assembly location is determined, the reference point is typically the center of gravity of the weight or weight assembly.
The location of a weight or weight assembly on a golf club head can be approximated by its coordinates on the head origin coordinate system, as described above. As described above, in some of the embodiments of the golf club head 400 described herein, the front weight channel 480 extends generally from a heelward end 486 oriented toward the heel side of the golf club head to a toeward end 488 oriented toward the toe side of the golf club head, with both the heelward end 486 and toeward end 488 being at or near the same distance from the front portion of the club head. As a result, in these embodiments, the front weight assembly 482 that is slidably retained within the weight channel 480 is capable of a relatively large amount of adjustment in the direction of the x-axis, while having a relatively small amount of adjustment in the direction of the y-axis. In some alternative embodiments, the heelward end 486 and toeward end 488 may be located at varying distances from the front portion, such as having the heelward end 486 further rearward than the toeward end 488, or having the toeward end 488 further rearward than the heelward end 486. In these alternative embodiments, the front weight assembly 482 that is slidably retained within the weight channel 480 is capable of a relatively large amount of adjustment in the direction of the x-axis, while also having from a small amount to a larger amount of adjustment in the direction of the y-axis.
For example, in some embodiments of a golf club head 400 having a front weight assembly 482 that is adjustably positioned within a weight channel 480, the front weight assembly 482 can have an origin x-axis coordinate between about −40 mm and about 40 mm, depending upon the location of the weight assembly within the weight channel 480. In specific embodiments, the front weight assembly 482 can have an origin x-axis coordinate between about −35 mm and about 35 mm, or between about −30 mm and about 30 mm, or between about −25 mm and about 25 mm, or between about −20 mm and about 20 mm, or between about −15 mm and about 15 mm, or between about −13 mm and about 13 mm. Thus, in some embodiments, the front weight assembly 482 is provided with a maximum x-axis adjustment range (Max Δx) that is less than 80 mm, such as less than 70 mm, such as less than 60 mm, such as less than 50 mm, such as less than 40 mm, such as less than 30 mm, such as less than 26 mm.
On the other hand, in some embodiments of the golf club head 400 having a front weight assembly 482 that is adjustably positioned within a weight channel 480, the front weight assembly 482 can have an origin y-axis coordinate between about 5 mm and about 80 mm. More specifically, in certain embodiments, the front weight assembly 482 can have an origin y-axis coordinate between about 5 mm and about 50 mm, between about 5 mm and about 45 mm, or between about 5 mm and about 40 mm, or between about 10 mm and about 40 mm, or between about 5 mm and about 35 mm. Additionally or alternatively, in certain embodiments, the front weight assembly 482 can have an origin y-axis coordinate between about 35 mm and about 80 mm, between about 45 mm and about 75 mm, or between about 50 mm and about 70 mm. Thus, in some embodiments, the weight member 480 is provided with a maximum y-axis adjustment range (Max Δy) that is less than 45 mm, such as less than 30 mm, such as less than 20 mm, such as less than 10 mm, such as less than 5 mm, such as less than 3 mm. Additionally or alternatively, in some embodiments having a rearward channel, the weight member is provided with a maximum y-axis adjustment range (Max Δy) that is less than 110 mm, such as less than 80 mm, such as less than 60 mm, such as less than 40 mm, such as less than 30 mm, such as less than 15 mm.
In some embodiments, a golf club head can be configured to have a constraint relating to the relative distances that the weight assembly can be adjusted in the origin x-direction and origin y-direction. Such a constraint can be defined as the maximum y-axis adjustment range (Max Δy) divided by the maximum x-axis adjustment range (Max Δx). According to some embodiments, the value of the ratio of (Max Δy)/(Max Δx) is between 0 and about 0.8. In specific embodiments, the value of the ratio of (Max Δy)/(Max Δx) is between 0 and about 0.5, or between 0 and about 0.2, or between 0 and about 0.15, or between 0 and about 0.10, or between 0 and about 0.08, or between 0 and about 0.05, or between 0 and about 0.03, or between 0 and about 0.01.
As discussed above, in some driver-type golf club head embodiments, the mass of the weight member, e.g. front weight assembly 482 or rear weight assembly 472, is between about 1 g and about 50 g, such as between about 3 g and about 40 g, such as between about 5 g and about 25 g. In some alternative embodiments, the mass of the front weight assembly 482 or rear weight assembly 472 is between about 5 g and about 45 g, such as between about 9 g and about 35 g, such as between about 9 g and about 30 g, such as between about 9 g and about 25 g.
In some embodiments, a golf club head can be configured to have constraints relating to the product of the mass of the weight assembly and the relative distances that the weight assembly can be adjusted in the origin x-direction and/or origin y-direction. One such constraint can be defined as the mass of the weight assembly (MWA) multiplied by the maximum x-axis adjustment range (Max Δx). According to some embodiments, the value of the product of MWA×(Max Δx) is between about 250 g·mm and about 4950 g·mm. In specific embodiments, the value of the product of MWA×(Max Δx) is between about 500 g·mm and about 4950 g·mm, or between about 1000 g·mm and about 4950 g·mm, or between about 1500 g·mm and about 4950 g·mm, or between about 2000 g·mm and about 4950 g·mm, or between about 2500 g·mm and about 4950 g·mm, or between about 3000 g·mm and about 4950 g·mm, or between about 3500 g·mm and about 4950 g·mm, or between about 4000 g·mm and about 4950 g·mm.
According to some embodiments, the value of the product of MWA×(Max Δx) is between about 250 g·mm and about 2500 g·mm. In specific embodiments, the value of the product of MWA×(Max Δx) is between about 350 g·mm and about 2400 g·mm, or between about 750 g·mm and about 2300 g·mm, or between about 1000 g·mm and about 2200 g·mm, or between about 1100 g·mm and about 2100 g·mm, or between about 1200 g·mm and about 2000 g·mm, or between about 1200 g·mm and about 1950 g·mm, or between about 1250 g·mm and about 1900 g·mm, or between about 1250 g·mm and about 1750 g·mm.
Another constraint relating to the product of the mass of the weight assembly and the relative distances that the weight assembly can be adjusted in the origin x-direction and/or origin y-direction can be defined as the mass of the weight assembly (MWA) multiplied by the maximum y-axis adjustment range (Max Δy). According to some embodiments, the value of the product of MWA×(Max Δy) is between about 0 g·mm and about 1800 g·mm. In specific embodiments, the value of the product of MWA×(Max Δy) is between about 0 g·mm and about 1500 g·mm, or between about 0 g·mm and about 1000 g·mm, or between about 0 g·mm and about 500 g·mm, or between about 0 g·mm and about 250 g·mm, or between about 0 g·mm and about 150 g·mm, or between about 0 g·mm and about 100 g·mm, or between about 0 g·mm and about 50 g·mm, or between about 0 g·mm and about 25 g·mm.
As noted above, one advantage obtained with a golf club head having a repositionable weight, such as the golf club head 400 having the front weight assembly 482, is in providing the end user of the golf club with the capability to adjust the location of the CG of the club head over a range of locations relating to the position of the repositionable weight. In particular, the present inventors have found that there is a distance advantage to providing a center of gravity of the club head that is lower and more forward relative to comparable golf clubs that do not include a weight assembly such as the forward front weight assembly 482 described herein.
In some embodiments, the golf club head 400 has a CG with a head origin x-axis coordinate (CGx) between about −10 mm and about 10 mm, such as between about −4 mm and about 9 mm, such as between about −3 mm and about 8 mm, such as between about −2 mm to about 5 mm, such as between about −0.8 mm to about 8 mm, such as between about 0 mm to about 8 mm. In some embodiments, the golf club head 400 has a CG with a head origin y-axis coordinate (CGy) greater than about 15 mm and less than about 50 mm, such as between about 22 mm and about 43 mm, such as between about 24 mm and about 40 mm, such as between about 26 mm and about 35 mm. In some embodiments, the golf club head 100 has a CG with a head origin z-axis coordinate (CGz) greater than about −8 mm and less than about 3 mm, such as between about −6 mm and about 0 mm. In some embodiments, the golf club head 100 has a CG with a head origin z-axis coordinate (CGz) that is less than 0 mm, such as less than −2 mm, such as less than −4 mm, such as less than −5 mm, such as less than −6 mm.
As described herein, by repositioning the forward front weight assembly 482 within the weight channel 480 of the golf club head 400, the location of the CG of the club head is adjusted. For example, in some embodiments of a golf club head 400 having a forward front weight assembly 482 that is adjustably positioned within a weight channel 480, the club head is provided with a maximum CGx adjustment range (Max ΔCGx) attributable to the repositioning of the front weight assembly 482 that is greater than 1 mm, such as greater than 2 mm, such as greater than 3 mm, such as greater than 4 mm, such as greater than 5 mm, such as greater than 6 mm, such as greater than 8 mm, such as greater than 10 mm, such as greater than 11 mm.
Moreover, in some embodiments of the golf club head 400 having a forward front weight assembly 482 that is adjustably positioned within a weight channel 480, the club head is provided with a CGy adjustment range (Max ΔCGy) that is less than 6 mm, such as less than 3 mm, such as less than 1 mm, such as less than 0.5 mm, such as less than 0.25 mm, such as less than 0.1 mm.
In some embodiments, a golf club head can be configured to have a constraint relating to the relative amounts that the CG is able to be adjusted in the origin x-direction and origin y-direction. Such a constraint can be defined as the maximum CGy adjustment range (Max ΔCGy) divided by the maximum CGx adjustment range (Max ΔCGx). According to some embodiments, the value of the ratio of (Max ΔCGy)/(Max ΔCGx) is between 0 and about 0.8. In specific embodiments, the value of the ratio of (Max ΔCGy)/(Max ΔCGx) is between 0 and about 0.5, or between 0 and about 0.2, or between 0 and about 0.15, or between 0 and about 0.10, or between 0 and about 0.08, or between 0 and about 0.05, or between 0 and about 0.03, or between 0 and about 0.01.
In some embodiments, a golf club head can be configured such that only one of the above constraints apply. In other embodiments, a golf club head can be configured such that more than one of the above constraints apply. In still other embodiments, a golf club head can be configured such that all of the above constraints apply.
The distance between weight channels/weight ports and weight size can contribute to the amount of CG change made possible in a golf club head, particularly in a golf club head used in conjunction with a removable sleeve assembly, as described above.
In some example embodiments of a golf club head having two, three, or more weights, a maximum weight mass multiplied by the distance between the maximum weight and the minimum weight is between about 100 g·mm and about 3,750 g·mm or about 200 g·mm and 2,000 g·mm. More specifically, in certain embodiments, the maximum weight mass multiplied by the weight separation distance is between about 500 g·mm and about 1,500 g·mm, between about 1,200 g·mm and about 1,400 g·mm.
When a weight or weight port is used as a reference point from which a distance, i.e., a vectorial distance (defined as the length of a straight line extending from a reference or feature point to another reference or feature point) to another weight or weights port is determined, the reference point is typically the volumetric centroid of the weight port. When a movable weight club head and sleeve assembly are combined, it is possible to achieve the highest level of club trajectory modification while simultaneously achieving the desired look of the club at address. For example, if a player prefers to have an open club face look at address, the player can put the club in the “R” or open face position. If that player then hits a fade (since the face is open) shot but prefers to hit a straight shot, or slight draw, it is possible to take the same club and move the heavy weight to the heel port to promote draw bias. Therefore, it is possible for a player to have the desired look at address (in this case open face) and the desired trajectory (in this case straight or slight draw).
In yet another advantage, by combining the movable weight concept with an adjustable sleeve position (effecting loft, lie and face angle) it is possible to amplify the desired trajectory bias that a player may be trying to achieve.
For example, if a player wants to achieve the most draw possible, the player can adjust the sleeve position to be in the closed face position or “L” position and also put the heavy weight in the heel port. The weight and the sleeve position work together to achieve the greater draw bias possible. On the other hand, to achieve the greatest fade bias, the sleeve position can be set for the open face or “R” position and the heavy weight is placed in the top port.
As described above, the combination of a large CG change (measured by the heaviest weight multiplied by the distance between the ports) and a large loft change (measured by the largest possible change in loft between two sleeve positions, Δloft) results in the highest level of trajectory adjustability. Thus, a product of the distance between at least two weight ports, the maximum weight, and the maximum loft change is important in describing the benefits achieved by the embodiments described herein.
In one embodiment, the product of the distance between at least two weight ports, the maximum weight, and the maximum loft change is between about 50 mm·g·deg and about 8,000 mm·g·deg, preferably between about 2000 mm·g·deg and about 6,000 mm·g·deg, more preferably between about 2500 mm·g·deg and about 4,500 mm·g·deg, or even more preferably between about 3000 mm·g·deg and about 4,100 mm·g·deg. In other words, in certain embodiments, the golf club head satisfies the following expressions in Equations 4-7. Notably, the maximum loft change may vary between 2-4 degrees, and a particular embodiment may have a maximum loft change of 4 degrees or ±2 degrees.
In the above expressions, Dwp, is the distance between two weight port centroids (mm), Mhw, is the mass of the heaviest weight (g), and Δloft is the maximum loft change (degrees) between at least two sleeve positions. A golf club head within the ranges described above will ensure the highest level of trajectory adjustability.
Additional disclosure regarding providing both a movable weight and an adjustable shaft assembly to a golf club head can be found in U.S. Pat. No. 8,622,847, the entire contents of which are incorporated by reference.
According to some example embodiments of a golf club head described herein, head areal weight, i.e., material density multiplied by the material thickness, of the golf club head sole, crown and skirt, respectively, is less than about 0.45 g/cm2 over at least about 50% of the surface area of the respective sole, crown and skirt. In some specific embodiments, the areal weight is between about 0.05 g/cm2 and about 0.15 g/cm2, between about 0.10 g/cm2 and about 0.20 g/cm2 between about 0.15 g/cm2 and about 0.25 g/cm2, between about 0.25 g/cm2 and about 0.35 g/cm2 between about 0.35 g/cm2 and about 0.45 g/cm2, or between about 0.45 g/cm2 and about 0.55 g/cm2.
According to some example embodiments of a golf club head described herein, the head comprises a skirt with a thickness less than about 0.8 mm, and the head skirt areal weight is less than about 0.41 g/cm2 over at least about 50% of the surface area of the skirt. In specific embodiments, the skirt areal weight is between about 0.15 g/cm2 and about 0.24 g/cm2, between about 0.24 g/cm2 and about 0.33 g/cm2 or between about 0.33 g/cm2 and about 0.41 g/cm2.
Some of the example golf club heads described herein can be configured to have a constraint defined as the moment of inertia about the golf club head CG x-axis (Ixx) multiplied by the total movable weight mass. According to some embodiments, the second constraint is between about 1.4 kg2·mm2 and about 40 kg2·mm2. In certain embodiments, the second constraint is between about 1.4 kg2·mm2 and about 2.0 kg2·mm2, between about 2.0 kg2·mm2 and about 10 kg2·mm2 or between about 10 kg2·mm2 and about 40 kg2·mm2.
Some of the example golf club heads described herein can be configured to have another constraint defined as the moment of inertia about the golf club head CG z-axis (Izz) multiplied by the total movable weight mass. According to some embodiments, the fourth constraint is between about 2.5 kg2·mm2 and about 72 kg2·mm2. In certain embodiments, the fourth constraint is between about 2.5 kg2·mm2 and about 3.6 kg2·mm2 between about 3.6 kg2·mm2 and about 18 kg2·mm2 or between about 18 kg2·mm2 and about 72 kg2·mm2.
In some embodiments described herein, a moment of inertia about a golf club head CG z-axis (Izz) can be greater than about 190 kg·mm2. More specifically, the moment of inertia about head CG z-axis 203 can be between about 190 kg·mm2 and about 300 kg·mm2, between about 300 kg·mm2 and about 350 kg·mm2, between about 350 kg·mm2 and about 400 kg·mm2, between about 400 kg·mm2 and about 450 kg·mm2, between about 450 kg·mm2 and about 500 kg·mm2 or greater than about 500 kg·mm2.
In some embodiments described herein, a moment of inertia about a golf club head CG x-axis (Ixx) can be greater than about 80 kg·mm2. More specifically, the moment of inertia about the head CG x-axis 201 can be between about 80 kg·mm2 and about 180 kg·mm2, between about 180 kg·mm2 and about 250 kg·mm2 between about 250 kg·mm2 and about 300 kg·mm2, between about 300 kg·mm2 and about 350 kg·mm2, between about 350 kg·mm2 and about 400 kg·mm2, or greater than about 400 kg·mm2.
Additional disclosure regarding areal weight and calculating values for moments of inertia providing both a movable weight and an adjustable shaft assembly to a golf club head can be found in U.S. Pat. No. 7,963,861, the entire contents of which are incorporated by reference.
In some embodiments, the surface of the sole 414 may comprise one or more surface features, such as a plurality of vortex generators 436, which as illustrated in
While in the illustrated embodiment, these vortex generators 436 are shown as being positioned on a sole 414, they may be placed, e.g., on a crown of a golf club head, elsewhere on the sole, or e.g., along a sole panel, along a toe surface, or at other locations on the surface of the golf club head in this or any of the golf club head embodiments illustrated herein, as desired.
In some embodiments, these vortex generators may have a greater height toward a rear of the golf club head, with wishbone “legs” that get narrower and shallower in height as they spread toward the face. In other embodiments (not pictured), these generators may be designed with, e.g., a point of greater height closer to the face and shorter and narrower legs spreading backwards, or other designs as may be desired.
While a wishbone shape is indicated, other shapes may provide advantageous effects, as well. Some examples include rectangular and star shaped projections or indentations, triangles, polygons, including, but not limited to, concave polygons, constructible polygons, convex polygons, cyclic polygons, decagons, digons, dodecagons, enneagons, equiangular polygons, equilateral polygons, henagons, hendecagons, heptagons, hexagons, Lemoine hexagons, Tucker hexagons, icosagons, octagons, pentagons, regular polygons, stars, and star polygons; triangles, including, but not limited to, acute triangles, anticomplementary triangles, equilateral triangles, excentral triangles, tritangent triangles, isosceles triangles, medial triangles, auxiliary triangles, obtuse triangles, rational triangles, right triangles, scalene triangles, Reuleaux triangles; parallelograms, including, but not limited to, equilateral parallelograms: rhombuses, rhomboids, and Wittenbauer's parallelograms; Penrose tiles; rectangles; rhombus; squares; trapezium; quadrilaterals, including, but not limited to, cyclic quadrilaterals, tetrachords, chordal tetragons, and Brahmagupta's trapezium; equilic quadrilateral kites; rational quadrilaterals; strombus; tangential quadrilaterals; tangential tetragons; trapezoids; polydrafters; annulus; arbelos; circles; circular sectors; circular segments; crescents; tunes; ovals; Reuleaux polygons; rotors; spheres; semicircles; triquetras; Archimedean spirals; astroids; paracycles; cubocycloids; deltoids; ellipses; smoothed octagons; super ellipses; and tomahawks; polyhedra; prisms; pyramids; and sections thereof, just to name a few.
In the illustrated embodiment, vortex generators 436 are illustrated as being positioned in the vicinity of the front channel 480, as well as on toe sole panel 448. Vortex generators incorporated into a composite panel may be particularly beneficial, because they can be molded along with the composite panel, which may reduce costs and simplify manufacture. However, as illustrated, the vortex generators 436 may also form part of the body and therefore be co-cast with the rest of the body of the golf club head. In such embodiments, the vortex generators are preferably cast in sufficient number and/or at positions away from area where heavy polishing of the golf club head takes place, so as to avoid having them polished away during the manufacturing process. Additionally, the vortex generators may comprise a three-dimensional decal or sticker that is adhered to the body and/or to a composite panel at a variety of locations, e.g. crown, sole, toe surface.
Golf club head 500 includes a hollow body 510 defining a crown portion (not shown), a skirt portion (not shown), a sole portion 514, and a striking surface (not shown). The body 510 further includes a hosel 520, which is adapted to receive a golf club shaft assembly 555. The body 510 further includes a heel portion 526, a toe portion 528, a front portion 530, and a rear portion 532. Included are a number of features that may improve playability, including at least an inertia generator 560, front channel 590, as well as composite panels on the sole 544, 548 and on the crown 535, along with discretionary mass elements, such as a removable front weight member 582, and an inertia generator mass element 585, and other additional features, as will be further described herein.
Positioned on a rear side of the inertia generator 560 is inertia generator mass element 585, which may comprise a steel or tungsten weight member or other suitable material. Inertia generator mass element 585 may be removably affixed to the rear of the inertia generator 560 using a fastener port 586 that is positioned in the rear of the inertia generator 560 and configured to receive a fastener 588, which may be removably inserted through an aperture 587 in the inertia generator mass element 585 and into the fastener port 586. Fastener port 586 and aperture 587 may be threaded so that fastener 588 can be loosened or tightened either to allow movement of, or to secure in position, inertia generator mass element 585. The fastener may comprise a head with which a tool (not shown) may be used to tighten or loosen the fastener, and a body that may, e.g., be threaded to interact with corresponding threads on the fastener port 586 and aperture 587 to facilitate tightening or loosening the fastener 588. The fastener port 586 can have any of a number of various configurations to receive and/or retain any of a number of fasteners, which may comprise simple threaded fasteners, such as described herein, or which may comprise removable weights or weight assemblies, such as described elsewhere herein and in the incorporated patents and applications.
Fastener port 586 may be angled diagonally in a manner similar to fastener port 386 so that the fastener 588 is angled downward away from the crown of the golf club head, and the fastener port is forward of a head of the fastener 588, which may provide a more secure attachment by “sandwiching” the portion of the inertia generator mass element 585 likely to have the greatest mass between the inertia generator 560 and the fastener 588.
Alternatively, in other embodiments (not pictured) inertia generator mass element 585 may be either integrally formed or affixed to the inertia generator using by bonding, gluing, brazing, or using one or more of the methods described herein and in the incorporated patents and applications.
One potential embodiment of an inertia generator mass element 585 that may be utilized with any of the embodiments herein weighs between 10 grams and 50 grams, such as between 10 grams and 30 grams or between 20 grams and 40 grams.
Positioned behind the front channel 590 and in front of and at least partially surrounded by forward portions of a heel sole insert 544 and toe sole insert 548 is a removable front weight member 582, which may comprise a steel or tungsten weight member or other suitable material.
Front weight member 582 may be removably affixed to the golf club head 500 and at least partially contained within a sole cavity 581 containing a fastener port 583 that is positioned in the sole 514 of the golf club head. Sole cavity 581 may be configured to have inner dimensions that are substantially coextensive with the outer dimensions of the front weight member 582, so that a bottom surface (opposite a crown of the golf club head) of the front weight member 582 is substantially parallel with the remainder of the surface of the sole 514. Further, front weight member 582 is configured to receive a fastener 584, which may be removably inserted through an aperture (not shown) in the front weight member, or can be configured to be otherwise suitably retained within the front weight member so that the weight member is firmly attached to the golf club head 500. Fastener port 583 and/or front weight member 582 may be threaded so that fastener 584 can be loosened or tightened to release or secure, respectively, the front weight member 582. The fastener may comprise a head with which a tool (not shown) may be used to tighten or loosen the fastener, and a body that may, e.g., be threaded to interact with corresponding threads on the fastener port 583 to facilitate tightening or loosening the fastener 584. The fastener port 583 can have any of a number of various configurations to receive and/or retain any of a number of fasteners, which may comprise simple threaded fasteners, such as described herein, or which may comprise removable weights or weight assemblies, such as described elsewhere herein and in the incorporated patents and applications.
While it is shown as being generally pentagonal in shape, it is to be understood that other shapes may be used for a removable front weight member 582. Additionally, in other embodiments (not pictured) a front weight member may be either integrally formed or affixed to the body 510 of the golf club head using by bonding, gluing, brazing, or using one or more of the methods described herein and/or in the incorporated patents and applications.
One potential embodiment of a front removable weight 582 that may be utilized with any of the embodiments herein weighs between 5 grams and 30 grams, such as between 5 grams and 20 grams or between 10 grams and 15 grams.
Golf club head 600 includes a hollow body 610 defining a crown portion (not shown), a skirt portion (not shown), a sole portion 614, and a striking surface (not shown). The body 610 further includes a hosel 620, which is adapted to receive a golf club shaft assembly (not shown). The body 610 further includes a heel portion 626, a toe portion 628, a front portion 630, and a rear portion 632. Included are a number of features that may improve playability, including at least an inertia generator 660, front channel 690, as well as composite panels on the sole 544 and on the crown (not shown), along with discretionary mass elements, such as a removable and repositionable front weight member 682, and an inertia generator mass element 672, and other additional features, as will be further described herein.
Club head 600 is provided with an elongated channel 680, as illustrated in
The elongated channel may provide an enlarged cavity 689 for introducing the weight assembly 682 into the channel and/or for removing or replacing the weight assembly 682. An additional enlarged recess 649 may be provided around the enlarged cavity, extending rearwardly to provide improved access to facilitate introducing the weight assembly 682, while also removing some additional discretionary mass from the club head. The weight assembly may also be provided with a fastener 684 to connect a first portion and a second portion of the weight assembly, in a manner similar to fastener 484 described above to secure the weight assembly 682 in a desired position within the elongate channel 680. In some embodiments, inertia generator mass element 672 may also be configured to be inserted into elongate channel 680 in a similar manner to weight assembly 682 to add additional discretionary mass forward of the golf club head. Additional disclosure regarding additional suitable potential methods and apparatus for fastening the weight assembly 682 and/or inertia generator mass element 672 are provided elsewhere herein and in the incorporated patents and applications.
As illustrated in
As illustrated in
As best illustrated in
In some embodiments, the surface of the sole 614 may comprise one or more surface features, such as a plurality of vortex generators 636, which may each comprise a “wishbone” shape, or one of the other shapes described herein. In the illustrated embodiment, vortex generators 636 are illustrated as being positioned on sole panel 644. Vortex generators incorporated into a composite panel may be particularly beneficial, because they can be molded along with the composite panel, which may reduce costs and simplify manufacture. However, as illustrated, the vortex generators 636 may also form part of the body and therefore be co-cast with the rest of the body of the golf club head. In such embodiments, the vortex generators are preferably cast in sufficient number and/or at positions away from area where heavy polishing of the golf club head takes place, so as to avoid having them polished away during the manufacturing process. Additionally, the vortex generators may comprise a three-dimensional decal or sticker that is adhered to the body and/or to a composite panel at a variety of locations, e.g. crown, sole, toe surface.
While in the illustrated embodiment, these vortex generators 636 are shown as being positioned on a forward edge of the composite sole panel 644, they may be placed, e.g., on a crown of a golf club head, elsewhere on the sole, or e.g., along a toe surface, or at other locations on the surface of the golf club head, as desired.
In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are only examples of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. We therefore claim as our invention all that comes within the scope and spirit of these claims.
This application is a continuation of U.S. patent application Ser. No. 17/696,664, filed Mar. 16, 2022, which is a continuation of U.S. patent application Ser. No. 16/660,561, filed Oct. 22, 2019, now U.S. Pat. No. 11,305,163, which claims the benefit of U.S. Provisional Application No. 62/755,319, filed Nov. 2, 2018, all of which are incorporated by reference herein in their entireties.
Number | Date | Country | |
---|---|---|---|
62755319 | Nov 2018 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 17696664 | Mar 2022 | US |
Child | 18662372 | US | |
Parent | 16660561 | Oct 2019 | US |
Child | 17696664 | US |