Golf Club Head with Improved Characteristic Time

This is a continuation of U.S. application Ser. No. 18/450,359, filed on Aug. 15, 2023, which claims the benefit of U.S. Provisional Application No. 63/371,449, filed Aug. 15, 2022, and U.S. Provisional Application No. 63/510,076, filed Jun. 23, 2023, the contents of which are fully incorporated herein by reference.

This disclosure relates generally to golf clubs and, more particularly, relates to driver-type club heads.

Golf club designers have desired to maximize the ball speed for driver-type club heads because more ball speed leads to increased carry distance and improved scores. Typically, designers will often look to various mass properties, such as center of gravity location, moment of inertia values, variable face thickness configurations, and other features as means to improve the ball speed of the club head. However, the United States Golf Association (USGA) have implemented limitations which restrict the performance of clubs. One of these limitations is Characteristic Time (CT), which the USGA measures using a CT test. The test measures how long a steel ball swung from a pendulum is in contact with the club face. CT measurement is indicative of the flexibility and energy transfer of the face. Although there is a limitation set out by the USGA to limit the CT of a club head, there is no limit on ball speed.

Throughout the years of golf, designers have been increasing the surface area and size of the strike surface in driver type club heads. A bigger striking surface has been recognized in the art to be advantageous in several ways. The striking surface can be analogous to a drum surface or a trampoline, where a larger surface will create more flexion/displacement of that surface. This holds true for golf club faces as well. As such, designers have tended to create a larger striking surface in order to provide greater face flexion and thus greater ball speeds. Further, it has also been well recognized in the art that the thickness of the striking surface significantly affects the ball speeds. It is common in the art for designers to seek the thinnest possible face within durability tolerances while not exceeding CT limits. As new, higher strength materials are employed in golf club head design, golf club head strike face thickness can be decreased while still preserving club head durability. Such a decrease in strike face thickness would increase the ball speed when struck, but also raise the golf club head CT. The ability to increase ball speed when struck with a given force is constrained by the requirement to limit the golf club head CT. Therefore, there is a need in the art for a driver-type golf club head that can produce higher ball speeds while still maintaining a conforming CT value.

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

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

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

Various embodiments of a golf club are illustrated in the figures. A golf club is generally understood to comprise a club head, which is configured to receive a shaft. A golf club further comprises a grip, which is secured to the shaft.

schematically illustrate various embodiments of a driver-type golf club head in various views. The features discussed below are demonstrated on club head. For ease of discussion, the features shown on club headare applicable to various embodiments of the club head according to the present invention. Any one or more of the features described in the various embodiments below can be used in combination with one another.

The club headcan comprise a strike faceand a bodysecured together to define a substantially closed/hollow interior cavity. The club headcomprises a crown, a soleopposite the crown, a heel, a toeopposite the heel, a front end, and a rear endopposite the front end. The bodycan further include a skirtand/or a trailing edgelocated between and adjoining the crownand the sole. The skirtcan extend from near the heelto near the toeof the club head.

A “driver-type golf club head,” also referred to as a driver, as described herein, can be defined by specific dimensional ranges. In particular, the driver, as described with regard to the invention disclosed herein, includes a loft angle, volume, length, depth, and height within the ranges defined below.

The “loft angle” of the driver can be less than approximately 16 degrees, less than approximately 15 degrees, less than approximately 14 degrees, less than approximately 13 degrees, less than approximately 12 degrees, less than approximately 11 degrees, or less than approximately 10 degrees.

The volume of the driver can be greater than approximately 300 cm3, greater than approximately 350 cm3, greater than approximately 400 cm3, greater than approximately 425 cm3, greater than approximately 450 cm3, greater than approximately 475 cm3, greater than approximately 500 cm3, greater than approximately 525 cm3, greater than approximately 550 cm3, greater than approximately 575 cm3, greater than approximately 600 cm3, greater than approximately 625 cm3, greater than approximately 650 cm3, greater than approximately 675 cm3, or greater than approximately 700 cm3.

The club headcan comprise one or more body materials such as steel, stainless steel, tungsten, aluminum, titanium, vanadium, chromium, cobalt, nickel, other metals, or metal alloys. In some embodiments, the body material can comprise a Ti-8Al-1Mo-1V alloy, or a 17-4 stainless steel. In some embodiments, the body material can be formed from C300, C350, Ni (Nickel)-Co (Cobalt)-Cr (Chromium)-Steel Alloy, 565 Steel, AISI type 304 or AISI type 630 stainless steel, 17-4 stainless steel, a titanium alloy, for example, but not limited to Ti-6-4, Ti-3-8-6-4-4, Ti-10-2-3, Ti 15-3-3-3, Ti 15-5-3, Ti185, Ti 6-6-2, Ti-7s, Ti-9s, Ti-92, or Ti-8-1-1 titanium alloy, an amorphous metal alloy, or other similar metals. In some embodiments, one or more portions of the club headcan comprise a non-metallic material.

The “ground plane,” as used herein, refers to a reference plane associated with the surface on which a golf ball is placed. The ground planecan be a horizontal plane tangent to the sole at an address position. Address position is defined in further detail below. The ground planeis illustrated in.

The “loft plane,” as used herein, refers to a reference plane that is tangent to a geometric center of the strike face (the “geometric center” is described in further detail below). Loft planeis illustrated in.

The term “loft angle,” as used herein, can refer to an angle measured between the loft planeand the XY plane (defined below). Loft angleis illustrated in.

The term “lie angle,” as used herein, can refer to an angle between a hosel axis, extending through the hosel, and the ground plane. The lie angleis measured from a front view of the club head, as illustrated in.

The club headcan define an “address position” (also referred to as “address”), wherein the club head is oriented such that club head forms its intended loft angleand lie angle. For example, at address position, the loft planeand an XY plane form the intended loft anglebetween one another. Likewise, at address position, the hosel axisand the ground planeform the intended lie anglebetween one another.

As illustrated in, the club headcan define a primary coordinate system centered about the geometric centerof the strike face. The primary coordinate system can comprise an X-axis, a Y-axis, and a Z-axis. The X-axiscan extend in a heel-to-toe direction, parallel to the ground plane. The X-axiscan be positive towards the heeland negative towards the toe. The Y-axiscan extend in a crown-to-sole direction and can be orthogonal to both the ground planeand the X-axis. The Y-axiscan be positive towards the crownand negative towards the sole. The Z-axiscan extend in front-to-rear direction, parallel to the ground plane, and can be orthogonal to both the X-axisand the Y-axis. The Z-axiscan be positive towards the strike faceand negative towards the rear end.

The primary coordinate system, as described herein, defines an XY plane as a vertical plane extending along the X-axisand the Y-axis. The primary coordinate system defines an XZ plane as a horizontal plane extending along the X-axisand the Z-axis. The primary coordinate system further defines a YZ plane as a vertical plane extending along the Y-axisand the Z-axis. The XY plane, the XZ plane, and the YZ plane are all perpendicular to one another and intersect at the primary coordinate system origin located at the geometric centerof the strike face. In these or other embodiments, the club headcan be viewed from a front view when the strike faceis viewed from a direction perpendicular to the XY plane. Further, in these or other embodiments, the club headcan be viewed from a side view or side cross-sectional view when the heelor toeis viewed from a direction perpendicular to the YZ plane.

The “body depth,” or “depth” DB of the club head, as used herein, refers to a front-to-rear dimension measured across the body. Referring to, the body depth DB is measured parallel to the Z-axisfrom a leading edgeto a rearward-most pointof the body. In many embodiments, the body depth DB can be measured according to a golf governing body such as the United States Golf Association (USGA).

The “body height,” or “height” HB of the club head, as described herein, can refer to a crown-to-sole dimension measured across the body. Referring to, the body height HB can be measured as a vertical distance (parallel to the Y-axis) between the ground planeand the highest point of the crown. In many embodiments, the body height HB can be measured according to a golf governing body such as the United States Golf Association (USGA).

The “body width,” or “width” WB of the club head, as described herein, can refer to a heel-to-toe dimension measured across the body. Referring to, the body width WB can be measured parallel to the X-axisfrom the heel apexto a toe apex. The toe apexis defined as the toeward-most point of the body. The heel apexis heelward-most point of the heelthat is located at a height 0.875 mm from the ground plane. In many embodiments, the body width WB can be measured according to a golf governing body such as the United States Golf Association (USGA). The ranges specified for the body depth DB, body height HB, and body width WB can be designed in accordance with the USGA regulations.

The “center of gravity” or “CG” of the club head, as described herein, can refer to the point at which the mass is centered within the club head. The CGis illustrated in.

The term or phrase “center of gravity position” or “CG location” can refer to the location of the club head center of gravity (CG) with respect to the primary coordinate system, wherein the CG position is characterized by locations along the X-axis, the Y-axis, and the Z-axis. The term “CGx” can refer to the CG location along the X-axis, measured from the geometric center. The term “CG height” can refer to the CG location along the Y-axis, measured from the geometric center. The term “CGy” can be synonymous with the CG height. The term “CG depth” can refer to the CG location along the Z-axis, measured from the geometric center. The term “CGz” can be synonymous with the CG depth.

The golf club head further comprises a secondary coordinate system centered about the center of gravity. As illustrated in, the secondary coordinate system comprises an X′-axis, a Y′-axis, and a Z′-axis. The X′-axisextends in a heel-to-toe direction. The X′-axisis positive towards the heeland negative towards the toe. The Y′-axisextends in a sole-to-crown direction and is orthogonal to both the Z′-axisand the X′-axis. The Y′-axisis positive towards the crownand negative towards the sole. The Z′-axisextends front-to-rear, parallel to the ground planeand is orthogonal to both the X′-axisand the Y′-axis. The Z′-axisis positive towards the strike faceand negative towards the rear end.

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

MOI is a measurement of an object's resistance to twisting about a given axis and is calculated according to Equation 1 below.

Equation 1 defines MOI, represented by I, of an object as the integral, with respect to mass (represented by dm), of the perpendicular distance between the axis about which MOI is being measured and the location of the mass of the object, represented by r, squared. It is generally known that, if the center of gravity (CG) of an object is known, that object may be treated as a point mass located at said CG. Treating an object as a point mass allows Equation 1 to be simplified to the following equation, Equation 2.

Equation 2 describes that the moment of inertia, I, of an object about a given axis is equal to the sum of the masses of all point masses of that object multiplied by the perpendicular distance between the axis about which MOI is being measured and each of the point masses.

The term “strike face,” as used herein, refers to a club head front surface that is configured to strike a golf ball. The term strike face can be used interchangeably with the term “face” or “strike face surface”.

The strike face comprises a “bulge curvature”, and a “roll curvature”. The bulge curvature is the curvature of the strike face in the heel-to-toe direction. The roll curvature is the curvature of the strike face in a crown-to-sole direction. The bulge curvature and the roll curvature each respectively comprise a “bulge radius” and a “roll radius” defining the radii of curvature associated with each of the bulge curvature and the roll curvature. The bulge curvature and/or the roll curvature can comprise one or more radii. The bulge and roll radii are designed and selected to improve off center hits of the golf ball. The bulge and roll radii define the boundaries of the strike face and the strike face perimeter.

The term “strike face (SF) perimeter,” as used herein, can refer to an edge of the strike face. The SF perimeteris located and defined at the point where the bulge radius and roll radius deviate from the bulge curvature and roll curvature, respectively. Referring to, the strike face perimeter includes a top edge, a toe edge, a bottom edge, and a heel edge. The strike face perimeter is the outermost bound of the strike face.

The “leading edge” of the club head, as described herein, can be identified as the most forward portion of the club head. The leading edgeis not necessarily a part of the strike face. The leading edgemay be located just below the bottom of the strike face bottom edge. For example, as illustrated in, the leading edgeis within the transition from the strike faceto the soleof the club head.

The “strike face height” or “face height” HSF of the club head, as used herein, refers to a distance measured from a strike face top edge pointto a strike face bottom edge pointwithin the YZ plane. The strike face top edge pointis defined by the intersection of the strike face top edgeand the YZ plane. Similarly, the strike face bottom edge pointis defined by the intersection of the strike face bottom edgeand the YZ plane. Referring to, the height HSF can be measured parallel to the loft plane, from the SF top edge pointto the SF bottom edge point, in the YZ plane which intersects face center.

The “strike face width” WSF of the club head, as used herein, refers to a horizontal distance measured across the strike face in a heel-to-toe direction. Referring to, the strike face width WSF can be measured parallel to the ground plane, from a heelward-most point of the strike face perimeter to a toeward-most point of the strike face perimeter.

The “top edge point height” HTP of the club head, as used herein, refers to the distance measured between the top edge pointand the ground plane, perpendicular to the ground plane, as illustrated in. The strike face top edge pointis defined by the intersection of the strike face top edgeand the YZ plane.

The “bottom edge point height” HBP of the club head, as used herein, refers to the distance measured between the bottom edge pointand the ground plane, perpendicular to the ground plane, as illustrated in. The strike face bottom edge pointis defined by the intersection of the strike face bottom edgeand the YZ plane.

The “crown apex height” HCA of the club head, as used herein, refers to the distance measured between a crown apex pointand the ground plane, perpendicular to the ground plane, as illustrated in. The crown apex pointis the highest point on the crownin the YZ plane.

The “crown apex depth” DCA of the club head, as used herein, refers to the distance measured between the top edge pointand the crown apex pointin the YZ plane, parallel to the Z-axis.

The “crown apex angle”of the club head, as used herein, refers to the angle of the crown apex pointrelative to the top edge point. The crown apex angleis measured as the angle between a line parallel to the Z-axis which intersects the crown apex pointand a line intersecting both the crown apex pointand top edge point.

The “sole apex depth” DSA of the club head, as used herein, refers to the distance measured between the bottom edge pointand a sole apex point. The sole apex pointis the lowest point on the solein the YZ plane and the point on the solein which the ground planeis tangent to.

The “sole apex angle”of the club head, as used herein, refers to the angle of the sole apex pointrelative to the ground plane. The sole apex angleis measured between a line which intersects the bottom edge pointand the sole apex pointand a the ground plane.

The “geometric center” of the strike face, as used herein, refers to a geometric center point of the strike face perimeter, illustrated in. The geometric center pointof the strike facecan be located in accordance with the definition of a golf governing body such as the United States Golf Association (USGA).

As illustrated in, the strike facecomprises a face center height HFC. The face center height HFC is measured from the ground planeto the geometric center, perpendicular to the ground plane.

As illustrated in, the club headfurther comprises a force lineintersecting the center of gravityand extending perpendicular to the loft plane. The launch characteristics of a golf ball are dependent on the relationship between the force lineand the impact location of the golf ball on the strike face. The closer the impact location is to the force line, the greater the energy transfer between the club headand the golf ball at impact. The force linecan be positioned offset relative to the face centerto adjust launch characteristics, assuming the golf ball will be struck at the face center.

Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways.