Golf club head or other ball striking device having stiffened face portion

A ball striking device, such as a golf club head, has a head that includes a face configured for striking a ball and a body connected to the face, the body being adapted for connection of a shaft proximate a heel thereof. The face includes one or more stiffening members or other structures on the inner surface of the face to provide locally increased stiffness to particular areas of the face. Certain stiffening members may provide greater stiffness than other stiffening members, allowing the face to be configured for areas of greatest stiffness and greatest COR tailored to common impact patterns.

TECHNICAL FIELD

The invention relates generally to ball striking devices, such as golf clubs and golf club heads, having a stiffened portion on the ball striking face thereof. Certain aspects of this invention relate to golf club heads having one or more stiffening members extending rearward from an inner surface of the face.

BACKGROUND OF THE INVENTION

Golf is enjoyed by a wide variety of players—players of different genders, and players of dramatically different ages and skill levels. Golf is somewhat unique in the sporting world in that such diverse collections of players can play together in golf outings or events, even in direct competition with one another (e.g., using handicapped scoring, different tee boxes, etc.), and still enjoy the golf outing or competition. 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.).

Despite the various technological improvements, golf remains a difficult game to play at a high level. To reliably propel a golf ball straight and in the desired direction, a golf club must meet the golf ball square (or substantially square) to the desired target path. Moreover, the golf club must meet the golf ball at or close to a desired location on the club head face (i.e., on or near a “desired” or “optimal” ball contact location) to reliably fly straight, in the desired direction, and for a desired distance. Off-center hits may tend to “twist” the club face when it contacts the ball, thereby sending the ball in the wrong direction, imparting undesired hook or slice spin, and/or robbing the shot of distance. Club face/ball contact that deviates from squared contact and/or is located away from the club's desired ball contact location, even by a relatively minor amount, also can launch the golf ball in the wrong direction, often with undesired hook or slice spin, and/or can rob the shot of distance. Accordingly, club head features that can help a user keep the club face square with the ball would tend to help the ball fly straighter and truer, in the desired direction, and often with improved and/or reliable distance.

Like other golf clubs, drivers and other “woods” also must make square contact with the golf ball, in the desired direction or path, in order to produce straight and true shots in the desired direction. Even small deviations from squareness between the club head and the golf ball at the point of contact can cause inaccuracy. Because drivers and other wood-type golf clubs typically launch the ball over greater distances than other clubs, these inaccuracies can be exaggerated.

Many off-center golf hits are caused by common errors in swinging the golf club that are committed repeatedly by the golfer, and which may be similarly committed by many other golfers. As a result, patterns can often be detected, where a large percentage of off-center hits occur in certain areas of the club face. For example, one such pattern that has been detected is that many high handicap golfers tend to hit the ball on the low-heel area of the club face and/or on the high-toe area of the club face. Other golfers may tend to miss the desired or optimal contact point in other areas of the club face. Because golf clubs typically are designed to contact the ball at or around the center of the face, such off-center hits may result in less energy being transferred to the ball, decreasing the distance of the shot. The energy or velocity transferred to the ball by a golf club also may be related, at least in part, to the flexibility of the club face at the point of contact, and can be expressed using a measurement called “coefficient of restitution” (or “COR”). The maximum COR for golf club heads is currently limited by the USGA at 0.83. Accordingly, a need exists to customize or adjust the local flexibility of a golf club face to provide maximized COR in the areas of the face where off-center hits tend to occur most, without exceeding current COR limitations.

The present devices and methods are provided to address the problems discussed above and other problems, and to provide advantages and aspects not provided by prior ball striking devices of this type. A full discussion of the features and advantages of the present invention is deferred to the following detailed description.

SUMMARY OF THE INVENTION

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 invention relate to ball striking devices, such as golf clubs, with a head that includes a face configured for striking a ball and a body connected to the face, the body being adapted for connection of a shaft proximate a heel thereof. Various example structures of faces described herein include one or more stiffening members or other structures on the inner surface of the face to provide locally increased stiffness to particular areas of the face. The faces of the golf club head structures may be formed to include targeted regions of increased stiffness (e.g., in the upper heel and/or lower toe quadrants), which leaves other, targeted regions of the face to have increased flexibility as compared to the stiffened regions. By locating the targeted regions of increased face flexibility at locations on a face where a golfer tends to hit the ball (e.g., high handicappers, as noted above, tend to hit balls in the lower heel or upper toe regions of the club face), the golf shot may experience increased “kick” off the face on off-center hits (provided the off-center hits impact the face at the locations of increased flexibility and at a sufficient velocity), e.g., due to the increased COR response at these off-center locations. While increasing the COR response at some off-center locations, the regions of increased stiffness may be used to control the overall club head's COR response and to assure that the COR of the club head remains within the constraints of the Rules of Golf.

According to one aspect, the face includes a first stiffening member extending rearward from its inner surface, a longitudinal center line of the first stiffening member extending between a first point and a second point. The first point is positioned in an upper heel quadrant of the face, and the second point is positioned in a lower toe quadrant of the face. Alternatively, the first and second points may be positioned such that the longitudinal center line of the first stiffening member extends in a direction from the upper heel quadrant toward the lower toe quadrant. The first stiffening member provides locally increased stiffness to an area of the face between the first point and the second point. Additionally, one or more secondary stiffening members may be provided that extend rearward from the inner surface of the face and provide locally increased stiffness to one or more other areas of the face. The first stiffening member may provide a greater degree of stiffness to the face relative to the secondary stiffening member(s). In some example structures, the secondary stiffening members can be arranged in one or more radiating formations.

According to another aspect of the invention, the face includes a stiffening member extending rearward from its inner surface, wherein the stiffening member includes a central longitudinal axis extending between a first point and a second point. The first point is located in an upper heel quadrant of the face, and the second point is located in a lower toe quadrant of the face. Alternatively, the first and second points may be positioned such that the longitudinal center line of the first stiffening member extends in a direction from the upper heel quadrant toward the lower toe quadrant. The stiffening member of this example structure has a width that is greater at the first point and at the second point than its width at the intermediate and central area thereof. In some example structures, the stiffening member is defined on opposed sides by concave curvilinear edges tapering or curving inward toward the center (i.e., toward the stiffening member's longitudinal axis). In other example structures, the stiffening member is defined by two curvilinear ribs diverging proximate the first point and the second point and converging at the center.

According to still another aspect of the invention, the face includes a stiffening member extending rearward from its inner surface, wherein the stiffening member includes a central longitudinal axis extending between a first point and a second point. The first point is located in an upper heel quadrant of the face, and the second point is located in a lower toe quadrant of the face. Alternatively, the first and second points may be positioned such that the longitudinal center line of the first stiffening member extends in a direction from the upper heel quadrant toward the lower toe quadrant. The stiffening member provides areas of locally increased stiffness to the face proximate the first point and the second point that are larger than the area of locally increased stiffness provided proximate the center of the stiffening member.

According to a further aspect of the invention, the face has a first stiffening member extending rearward from its inner surface, providing locally increased stiffness to areas of the face. The first stiffening member extends across the inner surface of the face such that a majority of the first stiffening member is located in the upper heel quadrant and the lower toe quadrant of the face. A plurality of second stiffening members may extend rearward from the inner surface of the face and also provide locally increased stiffness to areas of the face. In at least some example structures, a majority of the second stiffening members will be distributed in the upper toe quadrant and the lower heel quadrant of the face. As described above, in some example structures, the second stiffening members can be formed into one or more radiating formations, which may have central points in the high-toe and low-heel areas of the face (e.g., in the upper toe and lower heel quadrants of the face).

According to still further aspects of the invention, the face includes a stiffening member extending rearward from its inner surface, wherein the stiffening member includes a central longitudinal axis extending between a first point and a second point and across the center of the face. The first point is positioned proximate one edge of the face, and the second point is positioned proximate a second edge of the face substantially opposite the first point (e.g., from the upper heel corner to the lower toe corner). The inner surface of the face may have concave portions located on opposite sides of the stiffening member, and the concave portions each may have a concave thickness profile, having a face thickness that is greatest proximate the first point and the second point and lowest proximate the midpoint between the first point and the second point. In some example structures, the stiffening member may have a convex thickness profile, having a face thickness that is lowest proximate the first point and the second point and greatest proximate the midpoint.

According to yet further aspects of the invention, a plurality of stiffening members extending rearward from an inner surface of the face provide locally increased stiffness to the face. These stiffening members may be arranged to create at least two radiating formations, such that the stiffening members of each radiating formation radiate from a central point spaced from a center point of the face (e.g., spaced from the geometric center of the face).

According to additional aspects of the invention, the face may have a textured or toothed structure distributed across a majority of its inner surface. The toothed structure may include at least one row of indents extending across at least a portion of the inner surface. In one example structure, the toothed structure is formed in a two-dimensional grid structure, having a plurality of rows and columns of indents extending across at least a portion of the inner surface. In another example structure, the two-dimensional grid structure further includes a plurality of substantially linear horizontal and vertical ribs separating the indents, the ribs being raised with respect to the indents. The indents may have an inverted pyramidal shape.

According to still additional aspects of the invention, the face has a stiffening member extending rearward from its inner surface such that a central longitudinal axis of the stiffening member extends from a first contact point to a second contact point. The stiffening member of this example structure has at least two legs extending from the face and extending substantially perpendicular to the face at the first and second contact points and an arm extending between the legs, the arm being spaced from the inner surface of the face. The stiffening member provides locally increased stiffness to the face such that areas of the face surrounding the first and second contact points have locally greater stiffness relative to other areas of the face spaced from the contact points. In various example structures, the stiffening member may be oriented to extend in the high-heel to low-toe direction or the high-toe to low-heel direction (e.g., in a direction from the upper heel quadrant toward the lower toe quadrant or from the lower heel quadrant toward the upper toe quadrant, etc.), or the stiffening member may have a Y-shaped structure.

Another aspect of this invention relates to golf club heads including: (a) a face configured for striking a ball with an outer surface thereof; (b) a body connected to the face, the body adapted for connection of a shaft proximate a heel of the body and having a toe opposite the heel; and (c) an elongated stiffening member extending rearward from an inner surface of the face and extending across the inner surface of the face such that a central longitudinal axis of the stiffening member extends between a first point and a second point. In this example structure, the first point is positioned in or toward an upper heel quadrant of the face (as compared to the second point), and the second point is positioned in or toward the lower toe quadrant of the face (as compared to the first point), and the stiffening member includes an annular ring (e.g., round, elliptical, polygon, or oval shaped, etc.) surrounding an enclosed internal area, wherein the annular ring is thicker than the enclosed internal area. The stiffening member further may include a sloped transition region extending between the annular ring and the enclosed internal area and/or a sloped transition region extending between the annular ring and an area external to the annular ring (in such structures, the enclosed internal area may be thicker than the area external to the annular ring).

Still another aspect of this invention relates to golf club heads including: (a) a face configured for striking a ball with an outer surface thereof; (b) a body connected to the face, the body adapted for connection of a shaft proximate a heel of the body and having a toe opposite the heel; (c) a first stiffening member extending rearward from an inner surface of the face and extending across the inner surface of the face from a first location to a second location, the first location positioned in or toward an upper heel quadrant of the face (as compared to the second location), and the second location is positioned in or toward the lower toe quadrant of the face (as compared to the first location), the first stiffening member providing locally increased stiffness to the face, and wherein the first stiffening member includes a curved surface that faces the heel; and (d) a second stiffening member extending rearward from the inner surface of the face and extending across the inner surface of the face from a third location to a fourth location, the third location positioned in or toward an upper heel quadrant of the face (as compared to the fourth location), and wherein the second stiffening member includes a curved surface that faces the toe. Optionally, the fourth location may be in or toward the lower heel or lower toe quadrants of the face (as compared to the third location). The curved surfaces of the first and second stiffening members may face one another to define an internal area between the stiffening members. Additionally, the stiffening members may include sloped transition regions extending from their top surfaces to this internal area, and/or sloped transition regions extending from their top surfaces to areas external to the stiffening members and external to the internal area. Furthermore, if desired, the stiffening members may be mirror images of one another.

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

DETAILED DESCRIPTION

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,” “primary,” “secondary,” 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” 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 or handle member, and it may be attached to the shaft or handle in some manner.

The terms “shaft” and “handle” are used synonymously and interchangeably in this specification, and they 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. In many bonds made by “integral joining techniques,” separation of the joined pieces cannot be accomplished without structural damage thereto.

“Transverse” is not limited to perpendicular or generally perpendicular intersections, and refers broadly to a variety of angled intersections.

In general, aspects of this invention relate to ball striking devices, such as golf club heads, golf clubs, putter heads, putters, and the like. Such ball striking devices, according to at least some examples of the invention, may include a ball striking head and a ball striking surface. In the case of a golf club, the ball striking surface may constitute a substantially flat surface on one face of the ball striking head, although some curvature may be provided (e.g., “bulge” or “roll” characteristics). Some more specific aspects of this invention relate to wood-type golf clubs and golf club heads, including drivers, fairway woods, wood-type hybrid clubs, and the like, although aspects of this invention also may be practiced on irons, iron-type hybrid clubs, and the like, if desired.

According to various aspects of this invention, 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, fiber-reinforced composites, and wood, and the devices may be formed in one of a variety of configurations, without departing from the scope of the invention. In one 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 materials. It is understood that the head also may contain components made of several different materials. Additionally, the components may be formed by various forming methods. For example, metal components (such as titanium, aluminum, titanium alloys, aluminum alloys, steels (such as 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.

The various figures in this application illustrate examples of ball striking devices and portions thereof 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 to refer to the same or similar parts throughout.

At least some examples of ball striking devices according to this invention relate to golf club head structures, including heads for wood-type golf clubs, including drivers. Such devices may include a one-piece construction or a multiple-piece construction. An example structure of ball striking devices according to this invention will be described in detail below in conjunction withFIGS. 1 and 2, and will be referred to generally using reference numeral “100.”

FIG. 1illustrates an example of a ball striking device100in the form of a golf driver, in accordance with at least some examples of this invention. The ball striking device100includes a ball striking head102and a shaft104connected to the ball striking head102and extending therefrom. A ball106in use is also schematically shown inFIG. 1, in a position to be struck by the ball striking device100.

The ball striking head102of the ball striking device100ofFIG. 1has a face112connected to a body108, with a hosel109extending therefrom. Any desired hosel and/or head/shaft interconnection structure may be used without departing from this invention, including conventional hosel and/or head/shaft interconnection structures as are known and used in the art, including releasable head/shaft interconnections. For reference, the head102generally has a top116, a bottom or sole118, a heel120proximate the hosel109, a toe122distal from the hosel109, a front124, and a back or rear126. The shape and design of the head102may be partially dictated by the intended use of the device100. In the club100shown inFIGS. 1 and 2, the head102has a relatively large volume, as the club100is designed for use as a driver or wood-type club, intended to hit the ball accurately over long distances. In other applications, such as for a different type of golf club, the head may be designed to have different dimensions and configurations. When configured as a driver, the club head may have a volume of at least 400 cc, and in some structures, at least 450 cc, or even at least 460 cc. Other appropriate sizes for other club heads may be readily determined by those skilled in the art.

In the embodiment illustrated inFIG. 1, the head102has a hollow structure defining an inner cavity (e.g., defined by the face112and the body108). Thus, the head102has a plurality of inner surfaces defined therein. In one embodiment, the hollow center cavity may be filled with air. However, in other embodiments, the head102could be filled with another material, such as a foam. 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 cavity at all. It is understood that the inner cavity may not be completely enclosed in some embodiments.

The face112is located at the front124of the head102, and has a ball striking surface110located thereon. The ball striking surface110is configured to face a ball106in use, and is adapted to strike the ball106when the device100is set in motion, such as by swinging. As shown, the ball striking surface110occupies most of the face112. For reference purposes, the portion of the face112near the top face edge113and the heel120of the head102is referred to as the “high-heel area”160; the portion of the face112near the top face edge113and toe122of the head102is referred to as the “high-toe area”162; the portion of the face112near the bottom face edge115and heel120of the head102is referred to as the “low-heel area”164; and the portion of the face112near the bottom face edge115and toe122of the head102is referred to as the “low-toe area”166. Conceptually, these areas160-166may be recognized as quadrants of substantially equal size (and/or quadrants extending from a geometrical center of the face112), though not necessarily with symmetrical dimensions. The face112may include some curvature in the top to bottom and/or heel to toe directions (e.g., bulge and roll characteristics), as is known and is conventional in the art. In other embodiments, the surface110may occupy a different proportion of the face112, or the body108may have multiple ball striking surfaces110thereon. In the embodiment shown inFIG. 1, the ball striking surface110is inclined slightly (i.e., at a loft angle), to give the ball106slight lift and/or spin when struck. In other embodiments, the ball striking surface110may have a different incline or loft angle, to affect the trajectory of the ball106. Additionally, the face112may have one or more internal or external inserts in some embodiments.

It is understood that the face112, the body108, and/or the hosel109can be formed as a single piece or as separate pieces that are joined together. In one embodiment, the face112is formed from a cup-face structure, such as shown inFIGS. 10-21, with a wall or walls125extending rearward from the edges127of the inner face surface114. The body108can be formed as a separate piece or pieces joined to the walls125of the cup-face 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. If desired, the hosel109may be integrally formed as part of the cup-face.

The ball striking device100may include a shaft104connected to or otherwise engaged with the ball striking head102, as shown schematically inFIG. 1. The shaft104is adapted to be gripped by a user to swing the ball striking device100to strike the ball106. The shaft104can be formed as a separate piece connected to the head102, such as by connecting to the hosel109, as shown inFIG. 1. In other embodiments, at least a portion of the shaft104may be an integral piece with the head102, and/or the head102may not contain a hosel109or may contain an internal hosel structure. Still further embodiments are contemplated without departing from the scope of the invention. The shaft104may be constructed from one or more of a variety of materials, including metals, ceramics, polymers, composites, or wood. In some exemplary embodiments, the shaft104, or at least portions thereof, may be constructed of a metal, such as stainless steel, or a composite, such as a carbon/graphite fiber-polymer composite. However, it is contemplated that the shaft104may be constructed of different materials without departing from the scope of the invention, including conventional materials that are known and used in the art.

In general, the head102of the ball striking device100has one or more stiffening members extending rearward from the inner surface114of the face112for providing increased stiffness to certain areas or portions of the face112.FIGS. 2-23Billustrate various embodiments of ball striking faces200,300,400,500,600,700,800,900,1000,1100, having different numbers and configurations of stiffening members. Each of these configurations can be used as the face112of the ball striking device100as shown inFIG. 1, or various other configurations for ball striking devices within the scope of the present invention. Thus, common features of the face112and the faces200, et seq. described below are referred to with common reference numbers used to describe the face112ofFIG. 1.

FIGS. 2-6depict embodiments of a ball striking face200having a stiffening member202,204,206spaced from the inner surface114of the face200and extending across at least a portion of the face200. In each of these embodiments, the stiffening member202,204,206has a plurality of legs210, each attached to the inner surface114of the face200at a contact point212, and an arm or arms214extending between the legs210. The legs210extend away from the face substantially perpendicular to the inner surface114of the face200(although other angled extensions are possible), such that the arm214is spaced from the inner surface114. Connection of the legs210to the inner face surface114can be done by a variety of methods. In one embodiment, the legs210can be connected to the inner surface114by welding or another integral joining technique, and in other embodiments, the stiffening member202,204,206may be formed with the face200as a single, integral piece, or may be joined by fasteners, adhesive, or non-integral joining techniques. The stiffening member202,204,206provides locally increased stiffness to areas216of the face200surrounding the contact points212, relative to other areas of the face200located away from the contact points212.

In the embodiment shown inFIGS. 2 and 3, the stiffening member202extends in an angled manner across a portion of the face200in a direction from the high-heel area160toward the low-toe area166of the face200. This example stiffening member202has two contact points212with the face110, with one contact point212A located in the high-heel area160and the other contact point212B located in the low-toe area166of the face200. The arm214takes the form of a bar that extends between the legs210provided at the contact points212. In this configuration, the stiffening member202provides locally increased stiffness to the high-heel and low-toe areas160,166of the face200(and areas of relatively locally increased flexibility in the low-heel area162and high toe area164, e.g., areas of the face110where many golfers tend to contact the ball).

The contact points212A and212B may be located any desired distance apart. As some more specific examples, the contact points212A and212B may be located between 0.5 and 4.5 inches apart, and in some examples, between 0.75 and 4 inches apart, between 1 and 3.5 inches apart, or even between 1.25 and 3 inches apart. Also, the angle α of the arm214with respect to a horizontal direction (when the club is in a ball address position) may be between 10° and 80°, and in some example structures, between 20° and 70° or even between 30° and 60°.

In the embodiment shown inFIG. 4, the stiffening member204is similar to the stiffening member202ofFIGS. 2 and 3, but it is placed in the opposite orientation. The stiffening member204in this example structure extends in an angled manner across a portion of the face200in a direction from the low-heel area toward the high-toe area of the face200. This example stiffening member204has two contact points212, with one contact point212C located in the high-toe area162and the other contact point212D located in the low-heel area164of the face200. In this configuration, the stiffening member204provides locally increased stiffness to the high-toe and low-heel areas162,164of the face200(and it provides areas of relatively locally increased flexibility in the high heel area160and the low toe area166of the face110). The stiffening member204may have the size, relative positioning, and/or angle properties of the stiffening member202described above in conjunction withFIGS. 2 and 3.

In the embodiment shown inFIGS. 5 and 6, the stiffening member206has a Y-shaped configuration and extends across a portion of the face200. This stiffening member206has three contact points212, with one contact point212E located in the high-heel area160, a second contact point212F located in the high-toe area166, and a third contact point212G located proximate the low-center of the face200. The arm214takes the form of a Y-shaped bar that extends between the contact points212. In this configuration, the stiffening member206provides locally increased stiffness to the high-heel and high-toe areas160,162of the face200, as well as the center of the face200(and relatively locally increased flexibility to other areas of the face). It is understood that the Y-shaped stiffening member206may be oriented differently to provide locally increased stiffening to other portions of the face200, such as in a configuration that is inverted or rotated relative to the stiffening member206as shown inFIG. 5and/or shifted toward the toe or heel. The various arms of the Y-structure may have the same or different lengths without departing from this invention, and they may extend from a central area by consistent or different angles.

In the embodiments shown inFIGS. 2,4, and5, the legs210of the stiffening members202,204,206are obround or oval in cross-section, and the contact points212between the stiffening members202,204,206and the face200are also obround or oval. However, it is understood that the stiffening members202,204,206may have different cross-sections, and they may vary in cross-section at different portions along their length. It is also understood that the arm portions210of the stiffening member202,204,206may extend beyond the contact points212, such as in a cantilevered arrangement or into the rear of the ball striking face200. In other embodiments, the stiffening member may have a differently-shaped configuration (e.g., X-shape, square shape, diamond shape, etc.). In such embodiments, the stiffening member may have a different number of contact points as well. In further embodiments, the face200may have multiple stiffening members, which may be similar to the stiffening members202,204,206or may have another configuration, such as the stiffening members described below.

FIGS. 7-9illustrate another embodiment of a face300for a ball striking device, having a plurality of interconnected stiffening members302,304,306arranged in a radiating formation on the inner surface114of the face300. In the embodiment illustrated, the stiffening members302,304,306are integrally connected to the face300, such as by being formed integrally with the face300or by being connected by an integral joining technique. It is understood that in other embodiments, the stiffening members302,304,306may not be integrally connected to the face300. In the configuration illustrated inFIGS. 7-9, the primary stiffening member302extends in a high-heel to low-toe direction, from a first point310to a second point312on the inner surface114of the face300. In this example structure300, the first point310is located in the high-heel area160of the face and the second point312is located in the low-toe area166, and the primary stiffening member302extends generally across both the horizontal and vertical centerlines of the face300, but it does not extend to the edges of the face300. However in other embodiments, this may not be the case, and the primary stiffening member302may be arranged differently. For example, the primary stiffening member302may extend in the high-toe to low-heel direction, and may or may be positioned mostly or entirely on one half or on one quadrant of the face300. The center of the primary stiffening member302may be shifted in the horizontal and/or vertical directions.

A plurality of secondary stiffening members304are arranged proximate the primary stiffening member302in this example structure300such that the primary and secondary stiffening members302,304radiate from a central point308. The central point308is located proximate the center of the primary stiffening member302in the embodiment illustrated, and it may be located at the geometrical center of the face300, if desired (although off-center positions are possible). A disc-shaped central stiffening member306is also positioned centered at the point308. Generally, the primary stiffening member302is able to provide a greater degree of locally increased stiffness than the other stiffening members304,306. As seen inFIGS. 7-9, the secondary members304and the central member306have similar thicknesses, and the primary stiffening member302has a greater thickness relative to the other stiffening members304,306. Additionally, in this illustrated example structure300, the primary stiffening member302has a greater width relative to the secondary stiffening members304. In this embodiment, the increased stiffness of the primary member302and the areas around it results from the increased thickness and width thereof. In another embodiment, the primary stiffening member302may produce increased stiffness through another mechanism, such as by having greater yield strength or reduced flexibility. Such properties may be achieved, for example, through strengthening techniques or by using a different material for the primary stiffening member302.

If desired, any of the primary stiffening member302and/or the secondary stiffening members304and/or306may be offset from the center point308. Additionally or alternatively, if desired, the overall stiffening member need not have the generally symmetrical structure shown inFIG. 7. For example, the central stiffening member306need not be round, and/or the various stiffening member legs need not be aligned and/or of the same lengths.

While the stiffening members may have any desired dimensions, if desired, the secondary stiffening members304and/or306may be from about 0.1 to 2 mm thick, and optionally, from about 0.25 to 1.75 mm thick or from 0.5 to 1.5 mm thick. The primary stiffening member302may be from 20 to 200% thicker, e.g., from 0.12 to 6 mm thick, and in some examples, from 0.25 to 5 mm thick, or even from 0.5 to 4 mm thick. This “thickness” is measured as the distance the stiffening members extend away from the inner surface114of the face300. The entire area of the stiffening members302,304, and/or306combined may occupy from 5-50% of the interior surface area of the face, and in some examples, from 10-40% or even from 15-30% of this interior surface area.

FIGS. 10-17illustrate additional embodiments of ball striking faces400,500,600,700containing a plurality of stiffening members in accordance with examples of this invention. In these embodiments, the faces400,500,600,700are illustrated as part of a cup-face structure adapted to be connected to one or more body members (e.g., body108) as described above to form a ball striking device. The cup-face structure includes a wall or walls125(also called a “return portion”) extending rearward from the perimeter edges127of the face400,500,600,700, generally transverse to the face400,500,600,700. It is understood that the interior surface and/or variable face thickness features of the faces400, et seq. can be used in other types of face configurations without departing from this invention.

Each of the faces400, et seq. depicted inFIGS. 10-17contains a primary stiffening member402,502,602,702and a plurality of secondary stiffening members404,504,604,704extending rearward from the inner surface114of the face400, et seq. and providing locally increased stiffness to surrounding areas of the face400, et seq. Generally, the primary stiffening member402,502,602,702of each embodiment provides a greater degree of locally increased stiffness to the face400, et seq. than each of the secondary stiffening members404,504,604,704. The primary stiffening members402,502,602,702of these four example embodiments are substantially the same, and will be described below with reference to the primary stiffening member402of the face400illustrated inFIGS. 10 and 14. It is understood that the primary stiffening members502,602,702of the faces500,600,700ofFIGS. 11-13and15-17contain similar features, which are similarly referred to using the “500,” “600,” and “700” series of reference numbers, respectively. Likewise, the embodiment of the face900illustrated inFIGS. 20 and 21also contains a similar primary stiffening member902, and the features of the primary stiffening member902ofFIGS. 20 and 21are similarly referred to using the “900” series of reference numbers. The secondary stiffening members404,504,604,704of these faces400, et seq. are differently configured, and are described individually below with respect to each embodiment. In the embodiments illustrated, the stiffening members402,404,502,504,602,604,702,704are integrally connected to the face400, et seq., such as by being formed integrally with the face400, et seq. or being connected by an integral joining technique. It is understood that in other embodiments, however, the stiffening members402,404,502,504,602,604,702,704may not be integrally connected to the face400, et seq. Moreover, in a given face structure, the various stiffening members need not be structured, dimensioned, or connected to the face in a common manner. If desired, the primary stiffening members may be 25-300% thicker than the secondary stiffening members, and in some examples, from 50-200% thicker, or even 75-150% thicker (as measured from the rear surface114of the face), e.g., from 0.5 to 8 mm thick.

Generally, the primary stiffening member402illustrated inFIGS. 10 and 14extends across the inner surface114of the face400in an angled manner, in a high-heel to low-toe direction, from a first point410to a second point412on the inner surface114of the face400, such that the second point412is located toward the bottom115and the toe122of the face400relative to the first point410. In this embodiment, the first point410is located in the high-heel area160of the face and the second point412is located in the low-toe area166, and the primary stiffening member402extends across both the horizontal and vertical centerlines of the face400, to the edges127of the face400. However in other embodiments, this may not be the case, and the primary stiffening member402may be arranged differently (e.g., shifted toward the heel or toe, not as longitudinally long, angled at any desired direction from horizontal, etc.). As some additional examples, the primary stiffening member402may extend in the high-toe to low-heel direction, and/or it may be positioned mostly or entirely on one half or on one quadrant of the face400. Additionally, in this embodiment, the primary stiffening member402has transverse components414at opposite ends, extending transverse to the inner surface114and up the walls125of the cup face structure (although these transverse components414may be omitted, if desired).

This example primary stiffening member402has a tapered or curved configuration, having a greater width at its ends (e.g., near the first point410and the second point412) than at its center416. In this embodiment, the primary stiffening member402is elongated along an imaginary line of elongation (e.g., a central longitudinal axis) passing through the first and second points410,412, and the width of the primary stiffening member402is tapered or curved when measured generally perpendicular to the direction of the longitudinal axis of the primary stiffening member402. The primary stiffening member402illustrated inFIGS. 10 and 14is tapered or curved in a concavely-curved manner, and it is defined on opposed sides by concave curvilinear edges418tapering inward toward the center416. In this embodiment, the primary stiffening member402also includes gaps or recesses420at opposite ends, which may either be areas of reduced thickness compared to the adjacent areas of the member402or apertures extending completely through the member402. The shape of the gaps420illustrated inFIGS. 10 and 14gives the primary stiffening member402an X-shape, defined by two curvilinear ribs422diverging proximate the first point410and the second point412, separated by the gaps420, and then converging at the center416of the primary stiffening member402. Due to the increased width of the primary stiffening member402proximate the ends, the member402in this configuration can provide greater locally increased stiffness and/or a larger area of locally increased stiffness proximate the ends of the primary stiffening member402than at the center416thereof. As shown inFIGS. 10 and 14, a bulk or majority of the area of the primary stiffening member402is located in the high-heel area160and low-toe area166of the face400(e.g., in the high heel and low toe quadrants of the face400), and thus, the primary stiffening member402provides the greatest proportion of its strengthening and increased stiffness in the high-heel and low-toe areas160,166of the face400. Accordingly, this face400tends to be somewhat more flexible in the high-toe and low-heel quadrants, areas of the club head where many golfers tend to make contact with the ball. If desired, the primary stiffening member402may occupy about 5-30% of the inner surface area of the face400, and in some examples, from 5-25% of this area.

The secondary stiffening members404of the embodiment ofFIGS. 10 and 14take the form of substantially linear ribs that are arranged in a crossing pattern on the inner surface114of the face400. The pattern formed by the secondary stiffening members404in this illustrated example structure defines a plurality of triangular-shaped recesses or troughs424between the secondary stiffening members404. Additionally, the secondary stiffening members404are arranged to form a plurality of interconnected radiating formations426, wherein the secondary stiffening members404of each radiating formation426radiate from a central point428. The triangular recesses424also radiate from the central points428. Each of the central points428in this example structure400is positioned proximate the horizontal centerline of the face400, although some may be positioned slightly above the centerline (e.g., in the high-toe area162of the face), and some may be positioned slightly below the centerline (e.g., in the low-heel area164of the face), if desired. The secondary stiffening members404of this embodiment further contain transverse components430at the edges127of the face400, extending transverse to the inner surface114and up the walls125of the cup face structure, although these transverse components430need not be provided. The secondary stiffening members404provide locally increased stiffness to the surrounding areas of the face, centered at the central points428. In this embodiment, the locally increased stiffness provided by the primary stiffening member402is greater than the locally increased stiffness provided by the secondary stiffening members404. The secondary stiffening members404, when present, may occupy from 1-25% of the inner surface area of the face, and in some examples, from 2 to 20%, or even from 4 to 15%.

FIGS. 11 and 15depict another embodiment of a ball striking face500, in which the primary stiffening member502is similar to the primary stiffening member402of FIGS.10and14, as described above. InFIGS. 11 and 15, the secondary stiffening members504take the form of substantially linear ribs arranged to form two radiating formations526, wherein the secondary stiffening members504of each radiating formation526radiate from a central point528. One of the central points528in this example structure500is positioned in the high-toe area162of the face500, and the other central point528is positioned in the low-heel area164of the face500(although other arrangements are possible). Additionally, a circular disc-shaped stiffening member504A is positioned centered at each central point528, with the other secondary stiffening members504extending from the edges of the circular stiffening member504A. This configuration of the secondary stiffening members504produces a plurality of substantially triangular or wedge-shaped recesses or troughs524between the secondary stiffening members504. These wedge-shaped recesses524also radiate from the central point528. The secondary stiffening members504of this embodiment further contain transverse components530at the edges127of the face500, extending transverse to the inner surface114and up the walls125of the cup face structure (although the transverse components530may be omitted, if desired). The secondary stiffening members504provide locally increased stiffness to the surrounding areas of the face, centered at the points528. In this embodiment, the locally increased stiffness provided by the primary stiffening member502is greater than the locally increased stiffness provided by the secondary stiffening members504.

Any number of radiating formations526may be provided without departing from this invention, including, for example, from 1-5. The radiating formations526may cover, for example, from 1-25% of the inner surface area of the face, and in some examples, from 2-20%, or even from 4-15% of the interior face surface area.

FIGS. 12 and 16depict another embodiment of a ball striking face600, in which the primary stiffening member602is similar to the primary stiffening member402ofFIGS. 10 and 14, as described above. The secondary stiffening members604ofFIGS. 12 and 16are arranged in an approximate inverse relation to the secondary stiffening members404ofFIGS. 10 and 14. As shown inFIGS. 12 and 16, the secondary stiffening members604are formed as a plurality of triangular or wedge-shaped stiffening members604that are arranged to form a crossing pattern of substantially linear recesses or troughs624therebetween. Additionally, the secondary stiffening members604are arranged to form a plurality of radiating formations626, wherein the secondary stiffening members604of each radiating formation radiate from a central point628. The linear recesses624also radiate from the central points628. Each of the central points628is positioned proximate the horizontal centerline of the face600, although some may be positioned slightly above the centerline (e.g., in the high-toe area162of the face), and some may be positioned slightly below the centerline (e.g., in the low-heel area164of the face). The secondary stiffening members604provide locally increased stiffness to the surrounding areas of the face, centered at the central points628. In this embodiment, the locally increased stiffness provided by the primary stiffening member602is greater than the locally increased stiffness provided by the secondary stiffening members604. The secondary stiffening members604, when present, may occupy from 25% to 80% of the inner surface area of the face, and in some examples, from 50-75%.

FIGS. 13 and 17depict another embodiment of a ball striking face700, in which the primary stiffening member702is similar to the primary stiffening member402ofFIGS. 10 and 14, as described above. The secondary stiffening members704ofFIGS. 13 and 17are arranged in an approximate inverse relation to the secondary stiffening members504ofFIGS. 11 and 15. As shown inFIGS. 13 and 17, the secondary stiffening members704are formed as a plurality of substantially triangular or wedge-shaped stiffening members704that are arranged to form two radiating formations726, wherein the secondary stiffening members704of each radiating formation726radiate from a central point728. The secondary stiffening members704also form substantially linear recesses or troughs724therebetween, and the substantially linear recesses724also radiate from the central points728. One of the central points728is positioned in the high-toe area162of the face700, and the other central point728is positioned in the low-heel area164of the face700(although other arrangements are possible). Additionally, a circular disc-shaped recess724A is positioned centered at each central point728, with the other recesses724extending to the edges of the circular recess724A. The secondary stiffening members704provide locally increased stiffness to the surrounding areas of the face, centered at the central points728. In this embodiment, the locally increased stiffness provided by the primary stiffening member702is greater than the locally increased stiffness provided by the secondary stiffening members704. As withFIGS. 11 and 15, any number of radiating formations726may be provided, for example, from 1-5. The recesses that define the radiating formations726may cover, for example, from 1-25% of the inner surface area of the face, and in some examples, from 2-20%, or even from 4-15% of the interior surface area.

FIGS. 18 and 19illustrate another embodiment of a ball striking face800having a stiffening member802extending rearward from the inner surface114of the face800and having a central longitudinal axis extending across the face800between a first point810and a second point812. Generally, the stiffening member802extends across the inner surface114of the face800in an angled manner, e.g., in a high-heel to low-toe direction, such that the second point812is located toward the bottom115and the toe122of the face800relative to the first point810. In the embodiment illustrated inFIGS. 18 and 19, the first point810is located in the high-heel area160of the face800near the shaft connection area and the second point812is located in the low-toe area166, and the stiffening member802extends generally across both the horizontal and vertical centerlines of the face800, to the edges127of the face800. However, in other embodiments, this may not be the case, and the stiffening member802may be arranged differently. For example, the stiffening member802may extend in the high-toe to low-heel direction, and/or it may be positioned mostly or entirely on one half or on one quadrant of the face800. Additionally, in this embodiment, the stiffening member802has a convex thickness profile, having a thickness that is lowest proximate the first point810and/or the second point812and greatest proximate the midpoint or center816of the stiffening member802.

The stiffening member802of this example structure800has a tapered or curved configuration, having a greater width at the ends (e.g., near the first point810and the second point812) than at the center816of the stiffening member802. In this embodiment, the stiffening member802is elongated along a central longitudinal axis passing through the first and second points810,812, and the width of the stiffening member802is tapered or curved when measured generally perpendicular to the direction of elongation of the stiffening member802(e.g., perpendicular to its longitudinal axis). The stiffening member802illustrated inFIGS. 18 and 19is tapered in a concavely-curved manner, and it is defined on opposed sides by concave curvilinear edges818tapering inward toward the center816. Due to the increased width of the stiffening member802proximate the ends, the member802in this configuration can provide greater locally increased stiffness and/or a larger area of locally increased stiffness proximate the ends of the stiffening member802than at the center816thereof. As shown inFIGS. 18-19, a bulk or majority of the area of the primary stiffening member802is located in the high-heel quadrant and the low-toe quadrant of the face800, and thus, the primary stiffening member802provides the greatest proportion of its strengthening and increased stiffness in the high-heel and low-toe areas160,166of the face800. The primary stiffening member802of this example structure800may cover from 5-50% of the surface area of the inner surface of the face, and in some examples, from 10-45%, or even from 15-40% of the inner surface area. The primary stiffening member802may extend from 0.25 to 8 mm the inner surface of the face, and in some examples, from 0.5 to 6 mm, or even from 0.75 to 5 mm.

In the embodiment illustrated inFIGS. 18-19, the inner surface114of the face800has two concave portions840,844located on either side of the stiffening member802. A first concave portion840is located on one side842of the stiffening member802and a second concave portion844is located on the opposite side846of the stiffening member802. Each of the concave portions840,844has a concave thickness profile, having a face thickness that is greatest at the ends (i.e., as the concave portions840,844approach the first point810and the second point812, respectively) and having a face thickness that is lowest proximate the center of the concave portions840,844(e.g., proximate the center816of the stiffening member802). Accordingly, the concave portions840,844and the stiffening member802have opposite thickness profiles, and the concave portions840,844have their lowest face thickness (approximately at point847, e.g., optionally at the geometric center of the individual concave portions840,844) adjacent the point of the greatest face thickness of the stiffening member802(approximately at point849). In other embodiments, these thickness profiles may be different, and may be reversed, with the stiffening member having a concave profile and the adjacent portions of the face having a convex profile. Additionally, each of the concave portions840,844in this illustrated example structure is surrounded and defined by boundary recesses848, which separate the concave portions840,844from the edges125of the face800and also from the stiffening member802. As a result, the concave portions840,844also can be viewed as secondary stiffening members that are located on opposed sides of the (primary) stiffening member802, and that have thickness profiles that are different from or opposite to the primary stiffening member802. In this illustrated example structure800, the low heel and high toe areas164,162tend to have increased flexibility as compared to the high heel and low toe areas160,166.

FIGS. 20 and 21depict another embodiment of a ball striking face900, in which the primary stiffening member902is similar to the primary stiffening member402ofFIGS. 10 and 14, as described above (and may have the same thickness, angular, orientation, surface area coverage, and other features as described above forFIGS. 10 and 14). This example face900also has a textured or toothed structure formed on the inner surface114thereof. In the embodiment shown inFIGS. 20 and 21, the textured structure is formed by a plurality of substantially linear raised ribs or secondary stiffening members904arranged horizontally and vertically on the inner surface114to form a two-dimensional grid structure. The raised ribs904define indents950therebetween, and the grid structure forms rows and columns of indents950across the inner surface114of the face900. As shown inFIG. 21, the rising and falling sides952of the ribs904are sloped, so that the indents950are formed in an inverse-pyramidal shape. In the embodiment illustrated, the textured structure is formed on both sides954,956of the stiffening member902such that the entirety of the inner surface114of the face900is covered by the textured structure except for the portion occupied by the primary stiffening member902. However, it is understood that in other embodiments, larger or smaller portions of the inner surface114may be occupied by the textured structure (e.g., up to 50%, up to 60%, up to 75%, or higher). In this embodiment, the textured structure provides increased stiffness to the occupied areas of the face900, but less locally increased stiffness than at the locations corresponding to the stiffening member902. In other embodiments, the face900may have a different textured structure, which may or may not be formed in a grid pattern and/or which may or may not be in the form of inverse pyramids. In one particular such embodiment, the structure is inverted from the structure ofFIGS. 20 and 21, having a plurality of pyramid-shaped ribs or projections separated by a grid of horizontal and vertical linear recesses. In yet another embodiment, the ribs may be omitted and a side wall of an inverse-pyramidal shaped recess will extend upward to form a side wall of a pyramidal shaped projection.

FIGS. 22A and 22Billustrate another golf club face structure1000in accordance with an example of this invention. As illustrated, an elongated stiffening member1002extends rearward from an inner surface1004of the face1000and across the inner surface1004of the face1000such that a central longitudinal axis of the stiffening member1002extends between a first point1006and a second point1008. The first point1006in this examples structure1000is positioned in an upper heel quadrant of the face1000, and the second point1008is positioned in or toward the lower toe quadrant of the face1000from the first point1006. In the same manner as described above, the stiffening member1002provides locally increased stiffness to the face1000. The stiffening member1002may be integrally formed as part of the face1000or it may be a separate element that is engaged with the face1000.

In this illustrated example structure1000, the stiffening member1002includes an annular ring1010surrounding an enclosed internal area1012. The annular ring1010may be of any desired shape without departing from this invention, including, for example, round, oval, elliptical, polygon shaped (e.g., with 3 to 30 sides), etc. The overall width W of the ring1010may be constant or may change somewhat over its circumferential length (e.g., in the range from 1 mm to 10 mm, and in some examples, from 2 mm to 8 mm wide (e.g., in a direction generally parallel to the face).

The various parts of the face1000may have any desired thicknesses (in the direction away from the rear surface1004of the face1000) without departing from this invention. In the illustrated embodiment, the thickest portion of the annular ring1010may be about 4 mm thick, and the internal area1012may be about 2.7 mm thick. The area1014around and outside of the annular ring1010may be about 2.3 mm thick in this illustrated embodiment. Furthermore, this illustrated stiffening member1002includes a first transition region1016, e.g., that slopes between a top surface1010aof the annular ring1010and the internal area1012, and a second transition region1018, e.g., that slopes between the top surface1010aand the external area1014. While the illustrated transition regions1016and1018are substantially straight sloped regions (seeFIG. 22B), these regions1016and1018may be stepped, stepped or sloped at different rates or angles, curved, etc., without departing from this invention.

The specific dimensions and characteristics described above are simply examples. In accordance with at least some examples of this invention, the annular ring1010will be thicker than the enclosed internal area1012, and the enclosed internal area1012may be thicker than or the same thickness as the external area1014. Also, the thicknesses of these various areas1010,1012, and1014may be constant, substantially constant, or variable over the full extent of their respective areas. As some more specific examples, the annular ring1010may be from 2-8 mm thick, and in some examples from 2.5-6 mm thick; the internal area1012may be from 1-6 mm thick, and in some examples from 1.5-4 mm thick; and the external area1014may be from 1-6 mm thick, and in some examples from 1.5-4 mm thick. These thicknesses are measured as total thicknesses through the face at the specified locations.

The various areas1010,1012,1014,1016, and1018may occupy any desired percentage of the overall face surface area of the face without departing from this invention. The following table sets forth some potential ranges of surface area for these various areas:

Surface AreaSurface AreaSurface AreaRegionRange (%)Range (%)Range (%)10105-30%5-25%5-20%10125-40%10-35%15-35%101420-90%25-80%30-75%10161-25%2-20%2-20%10181-25%2-20%2-20%
The overall face may have any desired area, and for drivers, this area may be at least about 4.8 in2, and in some examples, in the range between 4.8 in2and 10 in2, and in some examples, between 5 in2and 8 in2.

The stiffening member1002may be of any desired longitudinal length L (e.g., from the first point1006to the second point1008) and located at any desired position on the golf club face1000without departing from this invention. While the illustrated example structure1000shows the stiffening member1002extending in a slanted direction from the upper heel quadrant to or toward the lower toe quadrant, other arrangements are possible, including from the lower heel quadrant to the upper toe quadrant. Also, the stiffening member1002may be located at any desired position along the face in the heel-to-toe direction, including closer to the heel or closer to the toe than illustrated inFIG. 22A. The stiffening member1002also may extend at any desired angle without departing from this invention, including, for example, at an angle of from 10-80 degrees from horizontal, and in some examples, from 20-70 degrees from horizontal or even from 30-60 degrees from horizontal. Also, the stiffening member1002need not extend completely from the top surface of the face1000to the bottom surface of the face1000, although it may extend this entire distance, if desired. In some example structures, the stiffening member1002will extend from 50-100% of the distance from the top surface of the face1000to the bottom surface of the face1000, and it may span 60-95% or even 70-90% of this distance.

FIGS. 23A and 23Billustrate still another example face member1100in accordance with this invention. In this illustrated face member1100, the overall stiffening member is similarly shaped to that illustrated inFIGS. 22A and 22B, but it is made from two separated portions, namely, first stiffening member1102aand second stiffening member1102b. The first stiffening member1102aextends rearward from an inner surface1104of the face1100and across the inner surface1104of the face1100from a first location1106ato a second location1108a. The first location1106ais positioned in an upper heel quadrant of the face1100, and the second location1108ais positioned in or toward the lower toe quadrant of the face1100from the first location1106a. As illustrated, the first stiffening member1102aincludes a top surface1110aand an inwardly curved surface1150athat faces the heel of the club. Furthermore, in this example structure1100, the second stiffening member1102bextends rearward from the inner surface1104of the face1100and across the inner surface1104of the face1100from a third location1106bto a fourth location1108b. The third location1106bis positioned in the upper heel quadrant of the face1106band the fourth location1108bmay be located, for example, in the lower toe or lower heel quadrants. The second stiffening member1102bincludes a top surface1110band an inwardly curved surface1150bthat faces the toe of the club. If desired, the first stiffening member1102aand the second stiffening member1102bmay be mirror images of one another, although this is not a requirement.

If desired, the curved surfaces1150aand1150bof the first and second stiffening members1102aand1102bmay face one another to define an internal area1112between the stiffening members1102aand1102b. Furthermore, as illustrated inFIGS. 23A and 23B, the first stiffening member1102amay include a first sloped transition region1116aextending from the top surface1110aof the first stiffening member1102ato the internal area1112, and the second stiffening member1102bmay include a second sloped transition region1116bextending from the top surface1110bof the second stiffening member1102bto the internal area1112. Similarly, the first stiffening member1102afurther may include a third sloped transition region1118aextending from the top surface1110aof the first stiffening member1102ato an area1114aexternal to the first stiffening member1102aand external to the internal area1112, and the second stiffening member1102bfurther may include a fourth sloped transition region1118bextending from the top surface1110bof the second stiffening member1102ato an area1114bexternal to the second stiffening member1102band external to the internal area1112. Instead of being sloped, the transition regions1116a,1116b,1118a, and/or1118bmay be stepped, curved, or otherwise shaped.

The various regions1110a,1110b,1112,1114a,1114b,1116a,1116b,1118a, and1118bmay have any desired thicknesses without departing from this invention, including the thickness ranges for the various corresponding areas described above forFIGS. 22A and 22B. The various regions1110a,1110b,1112,1114a,1114b,1116a,1116b,1118a, and1118balso may occupy any desired percentage of the overall face surface area without departing from this invention. The following table sets forth some potential ranges of surface area for these various areas:

Surface AreaSurface AreaSurface AreaRegionRange (%)Range (%)Range (%)1110a2.5-15%2.5-12.5%2.5-10%1110b2.5-15%2.5-12.5%2.5-10%11125-40%10-35%15-35%1114a10-45%12.5-40%15-37.5%1114b10-45%12.5-40%15-37.5%1116a0.5-12.5%1-10%1-10%1116b0.5-12.5%1-10%1-10%1118a0.5-12.5%1-10%1-10%1018b0.5-12.5%1-10%1-10%
The overall face may have any desired area, and for drivers, this area may be at least about 4.8 in2, and in some examples, in the range between 4.8 in2and 10 in2, and in some examples, between 5 in2and 8 in2.

The stiffening members1102aand1102bmay be of any desired length (e.g., from points1106aand1106bto1108aand1108b, respectively) and located at any desired positions on the golf club face1100without departing from this invention. While the illustrated example structure1100shows the stiffening members1102aand1102bcombined to form an overall slanted stiffening member structure1102from the upper heel quadrant toward the lower toe quadrant, other arrangements are possible, including from the lower heel quadrant to the upper toe quadrant. Also, the stiffening members1102aand1102bmay be located at any desired positions along the face in the heel-to-toe direction, separated by any desired distance, including closer to the heel and/or closer to the toe than illustrated inFIG. 23A. The stiffening members1102aand/or1102balso may extend at any desired angles without departing from this invention, including, for example, at angles of from 10-80 degrees from horizontal, and in some examples, from 20-70 degrees from horizontal or even from 30-60 degrees from horizontal. Also, the stiffening members1102aand/or1102bneed not extend completely from the top surface of the face1100to the bottom surface of the face1100, although they may extend this entire distance, if desired. In some example structures, the stiffening members1102aand/or1102bwill extend from 50-100% of the distance from the top surface of the face1100to the bottom surface of the face1100, and it may span 60-95% or even 70-90% of this distance.

It is understood that the ball striking faces200, et seq. described herein may have additional features affecting the flexibility of the face or areas thereof. For example, the faces200, et seq. may have additional areas of relatively increased or decreased face thickness. Additionally, the faces200, et seq. described herein may contain a greater or smaller number of stiffening members, and may contain multiple “primary” stiffening members (as described herein), creating additional areas of relative stiffness and flexibility. It is contemplated that in the embodiments described above with multiple stiffening members, various ones of the stiffening members may be formed of different materials or may be strengthened or otherwise designed with specific properties through processing techniques.

Heads102incorporating the faces200, et seq. disclosed herein may be used as a ball striking device or a part thereof. For example, a golf club100as shown inFIG. 1may be manufactured by attaching a shaft or handle104to the head102, as described above. In other embodiments, different types of ball striking devices can be manufactured according to the principles described herein.

The ball striking devices and heads therefor as described herein provide many benefits and advantages over existing products. For example, the stiffening members can be strategically located and designed to provide local stiffness and flexibility in the face of the head so that certain areas of the face will have a COR that is higher than other areas, without exceeding COR limits set by regulatory authorities. The head can be configured so that the areas of the face that most frequently impact the ball during play will have a higher COR. A ball impacting these specific locations on the face will have more energy and velocity transferred to it, thus resulting in longer hits.

While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and methods. Thus, the spirit and scope of the invention should be construed broadly as set forth in the appended claims.