Golf Club Set Having Similar Properties

The invention relates generally to a set of ball striking devices, such as a set of golf clubs, and more particularly to a set of golf clubs having similar properties between clubs of the set of clubs, such as club length.

This is a continuation of U.S. patent application Ser. No. 17/146,312, filed on Jan. 11, 2021, which is a continuation of U.S. patent application Ser. No. 16/058,872, filed Aug. 8, 2018, which is a continuation of U.S. patent application Ser. No. 14/721,720, filed May 26, 2015, now U.S. Pat. No. 10,065,087, issued Sep. 4, 2018, the contents of which are fully incorporated herein by reference.

Golf is enjoyed by a wide variety of players-players of different genders, and players of dramatically different ages and skill levels. These factors, together with increased golf programming on television (e.g., golf tournaments, golf news, golf history, and/or other golf programming) and the rise of well-known golf superstars, at least in part, have increased golf's popularity in recent years, both in the United States and across the world.

Golfers at all skill levels seek to improve their performance, lower their golf scores, and reach that next performance “level.” Manufacturers of all types of golf equipment have responded to these demands, and recent years have seen dramatic changes and improvements in golf equipment. For example, a wide range of different golf ball models now are available, with some balls designed to fly farther and straighter, provide higher or flatter trajectory, provide more spin, control, and feel (particularly around the greens), etc.

Being the sole instrument that sets a golf ball in motion during play, the golf club also has been the subject of much technological research and advancement in recent years. For example, the market has seen improvements in golf club heads, shafts, and grips in recent years. Additionally, other technological advancements have been made in an effort to better match the various elements of the golf club and characteristics of a golf ball to a particular user's swing features or characteristics (e.g., club fitting technology, ball launch angle measurement technology, etc.).

Typically a set of golf clubs includes 14 clubs. A set generally includes a putter, 3-4 wood-type clubs, and 9-10 iron-type clubs. Each of the clubs generally has different characteristics such as length, weight, stiffness, etc. These different characteristics require a golfer to learn a different swing for each golf club in the set of golf clubs. Generally, as one moves from a driver to a sand wedge, each club becomes progressively shorter and heavier which means a golfer's swing can vary significantly as he (or she) changes clubs.

In some cases a set of irons is produced to have a similar swing weight for each club. Swing weight is a measurement of how heavy a club feels to a player swinging the club. Measurement of swing weight is determined by the moment generated by the club about a fulcrum point usually 12 or 14 inches from the base (or grip end) of the golf club. The swing weight generally increases as the weight of the club head increases or the club length increases.

Learning to play golf can be very daunting for a beginning golfer. Learning to develop a repeatable golf swing in order can hit a ball with similar results is itself very difficult, and learning to swing a club that is slightly different from the next one within the set can add to this difficulty. The difficulty in learning golf can be a reason many potential players do not fully engage in the sport of golf.

The present disclosure addresses the problems discussed above and other problems, and provides advantages and aspects not provided by prior ball striking devices. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.

The following presents a general summary of aspects of the invention in order to provide a basic understanding of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a general form as a prelude to the more detailed description provided below.

Aspects of the disclosure relate to a set of golf clubs, each golf club having a golf club head and a shaft.

According to one aspect, a set of golf clubs can include at least one wood-type golf club having a wood-type golf club head having a striking face configured for striking a ball and a body extending rearwardly from the striking face, the body having a crown, a sole, a heel, and a toc, and a hosel including a hosel axis; and a shaft configured to engage with the wood-type golf club head. The at least one wood-type club can have a first length, a first lie angle, a first weight, a first swing weight, and a first center of gravity; and the at least one wood-type club can have a ground plane origin point located at the point at which a ground plane and the hosel axis intersect. The set of golf clubs can include at least one hybrid-type golf club having a hybrid-type golf club head having a striking face configured for striking a ball and a body extending rearwardly from the striking face, the body having a crown, a sole, a heel, and a toe, and a hosel including a hosel axis; and a shaft configured to engage with the hybrid-type golf club head. The at least one hybrid-type club can have a second length, a second lie angle, a second weight, a second swing weight, and a second center of gravity; and the at least one hybrid-type club can have a ground plane origin point located at the point at which a ground plane and the hosel axis intersect. The set of golf clubs can include at least one iron-type golf club having an iron-type golf club head having a striking face configured for striking a ball and a body extending rearwardly from the striking face, the body having a top surface, a sole, a heel, and a toe, and a hosel including a hosel axis; and a shaft configured to engage with the iron-type golf club head. The at least one iron-type club can have a third length, a third lie angle, a third weight, a third swing weight, and a third center of gravity; and the at least one iron-type club has a ground plane origin point located at the point at which a ground plane and the hosel axis intersect. The first, second, and third lengths can be substantially equal; and the first, second, and third lie angles can be substantially equal.

According to another aspect, a set of golf clubs can include a plurality of hybrid-type golf clubs, each hybrid-type golf club having a hybrid-type golf club head having a striking face configured for striking a ball and a body extending rearwardly from the striking face, the body having a crown, a sole, a heel, and a toe, and a hosel including a hosel axis; and a shaft configured to engage with the hybrid-type golf club head. Each of the plurality of hybrid-type golf clubs can have a first length, a first lie angle, a first weight, a first swing weight, and a first center of gravity, and a hosel including a hosel axis. Each of the plurality of hybrid-type clubs include ground plane origin point located at the point at which a ground plane and the hosel axis intersect. Each of the plurality of hybrid-type clubs can have a loft angle in the range of 21 degrees to 32 degrees. The set of golf clubs can include a plurality of iron-type golf clubs, each iron-type golf club having an iron-type golf club head having a striking face configured for striking a ball and a body extending rearwardly from the striking face, the body having a top surface, a sole, a heel, and a toe, and a hosel including a hosel axis; and a shaft configured to engage with the iron-type golf club head. Each of the plurality of iron-type golf clubs can have a second length, a second lie angle, a second weight, a second swing weight, and a second center of gravity. Each of the plurality of iron-type clubs include ground plane origin point located at the point at which a ground plane and the hosel axis intersect. Each of the plurality of iron-type clubs can have a loft angle in the range of 23 degrees to 60 degrees. The first, and second length can be substantially equal; and the first, and second lie angle can be substantially equal.

In another aspect, a set of golf clubs can include a plurality of wood-type golf clubs, each wood-type golf club having a wood-type golf club head having a striking face configured for striking a ball and a body extending rearwardly from the striking face, the body having a crown, a sole, a heel, and a toe, and a hosel including a hosel axis; and a shaft configured to engage with the wood-type golf club head. Each of the wood-type golf clubs can have a substantially similar length, a substantially similar lie angle, a substantially similar weight, a substantially similar swing weight, and a substantially similar center of gravity; and each of the plurality of wood-type clubs can have a loft angle in the range of 7 degrees to 26 degrees.

In another aspect, a set of golf clubs can include a plurality of iron-type golf clubs, each iron-type golf club having an iron-type golf club head having a striking face configured for striking a ball and a body extending rearwardly from the striking face, the body having a top surface, a sole, a heel, and a toc, and a hosel including a hosel axis; and a shaft configured to engage with the iron-type golf club head. Each of the iron-type golf clubs can have a substantially similar length, a substantially similar lie angle, a substantially similar weight, a substantially similar swing weight, and a substantially similar center of gravity; and each of the plurality of iron-type clubs can have a loft angle in the range of 23 degrees to 60 degrees.

Other features and advantages of the invention will be apparent from the following description taken in conjunction with the attached drawings.

In the following description of various example structures according to the invention, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various example devices, systems, and environments in which aspects of the invention may be practiced. It is to be understood that other specific arrangements of parts, example devices, systems, and environments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. Also, while the terms “top,” “bottom,” “front,” “back,” “side,” “rear,” and the like may be used in this specification to describe various example features and elements of the invention, these terms are used herein as a matter of convenience, e.g., based on the example orientations shown in the figures or the orientation during typical use. Additionally, the term “plurality,” as used herein, indicates any number greater than one, either disjunctively or conjunctively, as necessary, up to an infinite number. Nothing in this specification should be construed as requiring a specific three dimensional orientation of structures in order to fall within the scope of this invention. Also, the reader is advised that the attached drawings are not necessarily drawn to scale.

The following terms are used in this specification, and unless otherwise noted or clear from the context, these terms have the meanings provided below.

“Ball striking device” means any device constructed and designed to strike a ball or other similar objects (such as a hockey puck). In addition to generically encompassing “ball striking heads,” which are described in more detail below, examples of “ball striking devices” include, but are not limited to: golf clubs, putters, croquet mallets, polo mallets, baseball or softball bats, cricket bats, tennis rackets, badminton rackets, field hockey sticks, ice hockey sticks, and the like.

“Ball striking head” (or “head”) means the portion of a “ball striking device” that includes and is located immediately adjacent (optionally surrounding) the portion of the ball striking device designed to contact the ball (or other object) in use. In some examples, such as many golf clubs and putters, the ball striking head may be a separate and independent entity from any shaft member, and it may be attached to the shaft in some manner.

The terms “shaft” or “handle” include the portion of a ball striking device (if any) that the user holds during a swing of a ball striking device.

“Integral joining technique” means a technique for joining two pieces so that the two pieces effectively become a single, integral piece, including, but not limited to, irreversible joining techniques, such as adhesively joining, cementing, welding, brazing, soldering, or the like, where separation of the joined pieces cannot be accomplished without structural damage thereto.

“Generally parallel” means that a first line, segment, plane, edge, surface, etc. is approximately (in this instance, within 5%) equidistant from with another line, plane, edge, surface, etc., over at least 50% of the length of the first line, segment, plane, edge, surface, etc.

In general, aspects of this invention relate to sets of ball striking devices, such as a set of golf clubs, and the like. Such sets of ball striking devices, according to at least some examples of the invention, may include a ball striking head with a ball striking surface. In the case of a set of golf club, the ball striking surface is a substantially flat surface on one face of the ball striking head.

According to various aspects and embodiments, the ball striking device may be formed of one or more of a variety of materials, such as metals (including metal alloys), ceramics, polymers, composites (including fiber-reinforced composites), and wood, and may be formed in one of a variety of configurations, without departing from the scope of the invention. In one illustrative embodiment, some or all components of the head, including the face and at least a portion of the body of the head, are made of metal (the term “metal,” as used herein, includes within its scope metal alloys, metal matrix composites, and other metallic materials). It is understood that the head may contain components made of several different materials, including carbon-fiber composites, polymer materials, and other components. Additionally, the components may be formed by various forming methods. For example, metal components, such as components made from titanium, aluminum, titanium alloys, aluminum alloys, steels (including stainless steels), and the like, may be formed by forging, molding, casting, stamping, machining, and/or other known techniques. In another example, composite components, such as carbon fiber-polymer composites, can be manufactured by a variety of composite processing techniques, such as prepreg processing, powder-based techniques, mold infiltration, and/or other known techniques. In a further example, polymer components, such as high strength polymers, can be manufactured by polymer processing techniques, such as various molding and casting techniques and/or other known techniques.

The various figures in this application illustrate examples of ball striking devices according to this invention. When the same reference number appears in more than one drawing, that reference number is used consistently in this specification and the drawings refer to the same or similar parts throughout.

A set of golf clubs, as shown incan include any number golf clubs and can include any number of different types of golf clubs including wood-type golf clubs, including fairway woods, hybrid-type clubs, iron-type clubs, and putters. As shown, for example, ina set of golf clubs can include wood-type clubs, hybrid-type clubs, and iron-type clubs. Other example sets of golf clubs can include wood-type clubs, hybrid-type clubs, and iron-type clubsas shown in; only wood-type clubsas shown in; hybrid-type clubsand iron-type clubsas shown in, hybrid-type clubsand iron-type clubs as shown in, only iron-type clubs as shown in, or any combination of wood-type clubs, hybrid-type clubs, and iron-type clubs.

As will be described in more detail below, any number of clubs within a set of golf clubscan have similar characteristics between the clubs within the set of golf clubs. Such similarity between characteristics of the golf clubs can in some examples allow a user to more easily use the set of golf clubs. Such characteristics can include, for example, length of the golf clubs, lie angle of the golf clubs, weight of the golf clubs, swing weight of the golf clubs, location of center of gravity of the golf club heads, and the moments of inertia of the golf club heads.

At least some examples of a ball striking devices as described herein relate to golf clubs having head structures, including heads for wood-type golf clubs, such as drivers, fairway woods, hybrid clubs, iron-type clubs, and putters. Such devices may include a one-piece construction or a multiple-piece construction. Example structures of a set of ball striking devices according to this disclosure will be described in more detail below in conjunction withwhich illustrate embodiments of golf clubs that can be part of a set of golf clubs.

As discussed above, a set of golf clubscan include one or more wood-type golf clubwhich are shown and discussed in more detail in reference to. A wood-type golf clubas shown incan be configured as a driver, a fairway wood and any other type of wood-type club. A wood-type golf clubincludes a golf club head or a ball striking headconfigured to strike a ball in use and a shaftconnected to the ball striking headand extending therefrom.illustrate one embodiment of a ball striking head in the form of a golf club headthat has a striking faceconnected to a body, with a hoselextending therefrom and a shaftconnected to the hosel. For reference, the headgenerally has a top or crown, a bottom or sole, a heelproximate the hosel, a tocdistal from the hosel, a front, and a back or rear, as shown in. The shape and design of the headmay be partially dictated by the intended use of the golf club. For example, it is understood that the soleis configured to face the playing surface in use. With clubs that are configured to be capable of hitting a ball resting directly on the playing surface, such as a fairway wood, the solemay contact the playing surface in use, and features of the club may be designed accordingly. In the clubshown in, the headhas an enclosed volume, measured per “USGA PROCEDURE FOR MEASURING THE CLUB HEAD SIZE OF WOOD CLUBS”, TPX-3003, REVISION 1.0.0 dated Nov. 21, 2003. In this procedure, the volume of the club head is determined using the displaced water weight method. According to the procedure, any large concavities must be filled with clay or dough and covered with tape so as to produce a smooth contour prior to measuring volume. Club head volume may additionally or alternately be calculated from three-dimensional computer aided design (CAD) modeling of the golf club head. In other applications, such as for a different type of golf club, the headmay be designed to have different dimensions and configurations. For example, when configured as a driver, the club headmay have a volume of at least 360 cc, of at least 400 cc, and in some structures, at least 450 cc, or even at least 470 cc. The headillustrated in the form of a driver inhas a volume of approximately 460 cc, however the volume can be approximately 360 cc to 470 cc. The headcan also be configured as a fairway wood which can have a volume of approximately 120 cc to 250 cc.

The bodyof the headcan have various different shapes, including a rounded shape, as in the headshown in, a generally square or rectangular shape, or any other of a variety of other shapes. The shape of the club can be configured to distribute weight in any desired, manner, e.g., away from the faceand/or the geometric/volumetric center of the head, in order to create, for example, a lower center of gravity and/or a higher moment of inertia.

In the illustrative embodiment shown in, the headhas a hollow structure defining an inner cavity(e.g., defined by the faceand the body) with a plurality of inner surfaces defined therein. In one embodiment, the inner cavitymay be filled with air. However, in other embodiments, the inner cavitycould be filled or partially filled with another material, such as foam or hot melt. In still further embodiments, the solid materials of the head may occupy a greater proportion of the volume, and the head may have a smaller cavity or no inner cavityat all. It is understood that the inner cavitymay not be completely enclosed in some embodiments.

The faceis located at the frontof the headand has a ball striking surface (or striking surface)located thereon and an inner surfaceopposite the ball striking surface, as illustrated in. The ball striking surfaceis typically an outer surface of the faceconfigured to face a ball in use and is adapted to strike the ball when the golf clubis set in motion, such as by swinging. As shown, the ball striking surfaceis relatively flat, occupying at least a majority of the face. The facehas an outer periphery formed of a plurality of outer or peripheral edges. The edges of the facemay be defined as the boundaries of an area of the facethat is specifically designed to contact the ball in use, and may be recognized as the boundaries of an area of the facethat is intentionally shaped and configured to be suited for ball contact. The facemay include some curvature in the top to bottom and/or heel to toe directions (e.g., roll and bulge characteristics), as is known and is conventional in the art. In other embodiments, the surfacemay occupy a different proportion of the face, or the bodymay have multiple ball striking surfacesthereon. Generally, the ball striking surfaceis inclined with respect to the ground or contact surface (i.e., at a loft angle), to give the ball a desired trajectory and spin when struck, and it is understood, and as will be discussed in more detail below, different club headsmay have different loft angles. Additionally, the facemay have a variable thickness and also may have one or more internal or external inserts and/or supports in some embodiments. In one embodiment, the faceof the headmay be made from titanium (e.g., Ti-6Al-4V alloy or other alloy); however, the facemay be made from other materials in other embodiments.

It is understood that the face, the body, and/or the hoselcan be formed as a single piece or as separate pieces that are joined together. The facemay be formed as a face member with the bodybeing partially or wholly formed by one or more separate pieces connected to the face member. Such a face member may be in the form of, e.g., a face plate member or face insert, or a partial or complete cup-face member having a wall or walls extending rearward from the edges of the face. These pieces may be connected by an integral joining technique, such as welding, cementing, or adhesively joining. Other known techniques for joining these parts can be used as well, including many mechanical joining techniques, including releasable mechanical engagement techniques. As one example, a body member formed of a single, integral, cast piece may be connected to a face member to define the entire club head. The headinmay be constructed using this technique, in one embodiment. As another example, a single, integral body member may be cast with an opening in the sole. The body member is then connected to a face member, and a separate sole piece is connected within the sole opening to completely define the club head. Such a sole piece may be made from a different material, e.g., polymer or composite. As a further example, either of the above techniques may be used, with the body member having an opening on the top side thereof. A separate crown piece is used to cover the top opening and form part or the entire crown, and this crown piece may be made from a different material, e.g., polymer or composite. As yet another example, a first piece including the faceand a portion of the bodymay be connected to one or more additional pieces to further define the body. For example, the first piece may have an opening on the top and/or bottom sides, with a separate piece or pieces connected to form part or all of the crownand/or the sole. Further different forming techniques may be used in other embodiments.

The golf clubmay include a shaftconnected to or otherwise engaged with the ball striking headas shown in. The shaftis adapted to be gripped by a user to swing the golf clubto strike the ball. The shaftcan be formed as a separate piece connected to the head, such as by connecting to the hosel, as shown in. Any desired hosel and/or head/shaft interconnection structure may be used without departing from this invention, including conventional hosel or other head/shaft interconnection structures as are known and used in the art, or an adjustable, releasable, and/or interchangeable hosel or other head/shaft interconnection structure such as those shown and described in U.S. Patent Application Publication No. 2009/0062029, filed on Aug. 28, 2007, U.S. Patent Application Publication No. 2013/0184098, filed on Oct. 31, 2012, and U.S. Pat. No. 8,533,060, issued Sep. 10, 2013, all of which are incorporated herein by reference in their entireties and made parts hereof. The headmay have an opening or other access for the adjustable hoselconnecting structure that extends through the sole, as seen in. In other illustrative embodiments, at least a portion of the shaftmay be an integral piece with the head, and/or the headmay not contain a hoselor may contain an internal hosel structure. Still further embodiments are contemplated without departing from the scope of the invention.

The shaftmay be constructed from one or more of a variety of materials, including metals, ceramics, polymers, composites, or wood. In some illustrative embodiments, the shaft, or at least portions thereof, may be constructed of a metal, such as stainless steel or titanium, or a composite, such as a carbon/graphite fiber-polymer composite. However, it is contemplated that the shaftmay be constructed of different materials without departing from the scope of the invention, including conventional materials that are known and used in the art. A grip elementmay be positioned on the shaftto provide a golfer with a slip resistant surface with which to grasp the golf club shaft, as seen in. The grip element may be attached to the shaftin any desired manner, including in conventional manners known and used in the art (e.g., via adhesives or cements, threads or other mechanical connectors, swedging/swaging, etc.).

The various embodiments of golf clubsand/or golf club headsdescribed herein may include components that have sizes, shapes, locations, orientations, etc., that are described with reference to one or more properties and/or reference points. Several of such properties and reference points are described in the following paragraphs, with reference to.

As illustrated in, a lie angleis defined as the angle formed between the hosel axisor a shaft axisand a horizontal plane contacting the sole, i.e., the ground plane. It is noted that the hosel axisand the shaft axisare central axes along which the hoseland shaftextend.

One or more origin points(e.g.,A,B) may be defined in relation to certain elements of the golf clubor golf club head. Various other points, such as a center of gravity, a sole contact, and a face center, may be described and/or measured in relation to one or more of such origin points.illustrate two different examples of such origin points, including their locations and definitions. A first origin point location, referred to as a ground plane origin pointA is generally located at the ground plane. The ground plane origin pointA is defined as the point at which the ground planeand the hosel axisintersect. A second origin point location, referred to as a hosel origin pointB, is generally located on the hosel. The hosel origin pointB is defined on the hosel axisand coincident with the uppermost edge of the hosel. Either location for the origin point, as well as other origin points, may be utilized for reference without departing from this invention. It is understood that references to the ground plane origin pointA and hosel origin pointB are used herein consistent with the definitions in this paragraph, unless explicitly noted otherwise. Throughout the remainder of this application, the ground plane origin pointA will be utilized for all reference locations, tolerances, calculations, etc., unless explicitly noted otherwise.

As illustrated in, a coordinate system may be defined with an origin located at the ground plane origin pointA, referred to herein as a ground plane coordinate system. In other words, this coordinate system has an X-axis, a Y-axis, and a Z-axisthat all pass through the ground plane origin pointA. The X-axis in this system is parallel to the ground plane and generally parallel to the striking surfaceof the golf club head. The Y-axisin this system is perpendicular to the X-axisand parallel to the ground plane, and extends towards the rearof the golf club head, i.e., perpendicular to the plane of the drawing sheet in. The Z-axisin this system is perpendicular to the ground plane, and may be considered to extend vertically. Throughout the remainder of this application, the ground plane coordinate system will be utilized for all reference locations, tolerances, calculations, etc., unless explicitly noted otherwise.

illustrate an example of a center of gravity locationas a specified parameter of the golf club head, using the ground plane coordinate system. The center of gravity of the golf club headmay be determined using various methods and procedures known and used in the art. The golf club headcenter of gravity locationis provided with reference to its position from the ground plane origin pointA. As illustrated in, the center of gravity locationis defined by a distance CGXfrom the ground plane origin pointA along the X-axis, a distance CGYfrom the ground plane origin pointA along the Y-axis, and a distance CGZfrom the ground plane origin pointA along the Z-axis.

Additionally as illustrated in, another coordinate system may be defined with an origin located at the hosel origin pointB, referred to herein as a hosel axis coordinate system. In other words, this coordinate system has an X′ axis, a Y′ axis, and a Z′ axisthat all pass through the hosel origin pointB. The Z′ axisin this coordinate system extends along the direction of the shaft axis(and/or the hosel axis). The X′ axisin this system extends parallel with the vertical plane and normal to the Z′ axis. The Y′ axisin this system extends perpendicular to the X′ axisand the Z′ axisand extends toward the rearof the golf club head, i.e., the same direction as the Y-axisof the ground plane coordinate system.

illustrates an example of a center of gravity locationas a specified parameter of the golf club head, using the hosel axis coordinate system. The center of gravity of the golf club headmay be determined using various methods and procedures known and used in the art. The golf club headcenter of gravity locationis provided with reference to its position from the hosel origin pointB. As illustrated in, the center of gravity locationis defined by a distance ΔXfrom the hosel origin pointB along the X′ axis, a distance ΔY (not shown) from the hosel origin pointB along the Y′ axis, and a distance ΔZfrom the hosel origin pointB along the Z′ axis.

illustrate the face center (FC) locationon a golf club head. The face center locationillustrated inis determined using United States Golf Association (USGA) standard measuring procedures from the “Procedure for Measuring the Flexibility of a Golf Clubhead”, USGA TPX-3004, Revision 2.0, Mar. 25, 2005. Using this USGA procedure, a template is used to locate the FC locationfrom both a heelto toelocation and a crownto solelocation. For measuring the FC locationfrom the heel to toe location, the template should be placed on the striking surfaceuntil the measurements at the edges of the striking surfaceon both the heeland toeare equal. This marks the FC locationfrom a heel to toe direction. To find the face center from a crown to sole dimension, the template is placed on the striking surfaceand the FC locationfrom crown to sole is the location where the measurements from the crownto soleare equal. The FC locationis the point on the striking surfacewhere the crown to sole measurements on the template are equidistant, and the heel to toe measurements are equidistant.

As illustrated in, the FC locationcan be defined from the ground plane origin coordinate system, such that a distance CFXis defined from the ground plane origin pointA along the X-axis, a distance CFYis defined from the ground plane origin pointA along the Y-axis, and a distance CFZis defined from the ground plane origin pointA along the Z-axis. It is understood that the FC locationmay similarly be defined using the hosel origin system, if desired.

illustrates an example of a loft angleof the golf club head. The loft anglecan be defined as the angle between a planethat is tangential to the striking surfaceat the FC locationand an axisnormal or perpendicular to the ground plane. Alternately, the loft anglecan be defined as the angle between an axisnormal or perpendicular to the striking surfaceat the FC location, called a face center axis, and the ground plane. It is understood that each of these definitions of the loft anglemay yield the substantially the same loft angle measurement.

illustrates an example of a face angleof a golf club head. As illustrated in, the face angleis defined as the angle between the face center axisand a planeperpendicular to the X-axisand the ground plane.

illustrates a golf club headoriented in a reference position. In the reference position, the hosel axisor shaft axislies in a vertical plane, as shown in. As illustrated in, the hosel axismay be oriented at the lie angle. The lie angleselected for the reference position may be the golf clubmanufacturer's specified lie angle. If a specified lie angle is not available from the manufacturer, a lie angle of 60 degrees can be used. Furthermore, for the reference position, the striking surfacemay, in some circumstances, be oriented at a face angleof 0 degrees. The measurement setup for establishing the reference position can be found determined using the “Procedure for Measuring the Club Head Size of Wood Clubs”, TPX-3003, Revision 1.0.0, dated Nov. 21, 2003.

The moment of inertia is a property of the club head. There are three moment of inertia properties referenced herein. The moment of inertia with respect to an axis parallel to the X-axisof the ground plane coordinate system, extending through the center of gravityof the club head, is referenced as the MOI x-x, as illustrated in. The moment of inertia with respect to an axis parallel to the Z-axisof the ground plane coordinate system, extending through the center of gravityof the club head, is referenced as the MOI z-z, as illustrated in. The moment of inertia with respect to the Z′ axisof the hosel axis coordinate system is referenced as the MOI h-h, as illustrated in. The MOI h-h can be utilized in determining how the club headmay resist the golfer's ability to close the clubface during the swing.

The ball striking face height (FH)is a measurement taken along a plane normal to the ground plane and defined by the dimension CFXthrough the face center, of the distance between the ground planeand a point represented by a midpoint of a radius between the crownand the face. An example of the measurement of the face heightof a headis illustrated in. It is understood that the club headsdescribed herein may be produced with multiple different loft angles, and that different loft angles may have some effect on face height.