The invention relates generally to ball striking devices, such as golf clubs and heads. Certain aspects of this invention relate to golf clubs and golf club heads having a deformation limiting member that limits deformation of the face.
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 golfs 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. For a golf ball to reliably fly straight and in the desired direction, a golf club should meet the golf ball square (or substantially square) to the desired target path. Moreover, the golf club should 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 that deviate from squared contact and/or are located away from the club's desired ball contact location may tend to “twist” the club face when it contacts the ball, thereby sending the ball in the wrong direction, often imparting undesired hook or slice spin, and/or robbing the shot of distance. Thus, when the club face is not square at the point of engagement, the golf ball may fly in an unintended direction and/or may follow a route that curves left or right, ball flights that are often referred to as “pulls,” “pushes,” “draws,” “fades,” “hooks,” or “slices,” or may exhibit more boring or climbing trajectories.
The energy and velocity transferred to the ball by a golf club 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. Generally, a club head will have an area of highest response relative to other areas of the face, such as having the highest COR, which imparts the greatest energy and velocity to the ball, and this area is typically positioned at the center of the face. In one example, the area of highest response may have a COR that is up to the prevailing USGA limit (e.g. 0.83), which limit may change over time. However, because golf clubs are typically designed to contact the ball at or around the center of the face, off-center hits may result in less energy being transferred to the ball, decreasing the distance of the shot. The COR at a specific location on the club head can be related to the modulus of elasticity at the impact location, as well as the modulus of other areas of the face spaced away from the impact location. Similarly, the contact time between the ball and the face during impact can affect energy transfer. Generally, a more flexible (lower modulus) face will produce higher contact times, resulting in greater energy transfer. The contact time is currently limited by the USGA at 257 μs, according to the USGA Characteristic Time (CT) test. Club head features that can increase the energy transferred to a ball during impact can be advantageous.
It is common for professional golfers and other experienced golfers to have higher swing speeds (i.e., the speed of the club head at or around impact with the ball) than less experienced golfers. Many club heads are designed to deliver optimal performance at higher swing speeds, and may offer less optimal performance at lower swing speeds. Accordingly, club head features that can improve performance at lower swing speeds and can allow players having low swing speeds to achieve greater ball speeds can prove to be advantageous for use by less experienced golfers. Additionally, club head features that can improve performance at lower swing speeds, while not impeding the ball speed achieved at higher swing speeds can prove to be advantageous.
The present device and method 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, 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 invention relate to ball striking devices, such as golf clubs, with a head that includes a face having a ball striking surface configured for striking a ball and an inner surface opposite the ball striking surface, as well as a body connected to the face and extending rearward from the face. The head has a deformation limiting member located behind the face and having an end spaced a distance from the inner surface of the face. The face and the deformation limiting member are adapted such that an impact of the ball on the ball striking surface causes deformation of the face toward the deformation limiting member. When the deformation of the face is sufficient to cause the inner surface of the face to engage the deformation limiting member, the deformation limiting member exerts a force on the face to resist further deformation of the face.
According to one aspect, the face is adapted such that impacts of the ball on the face below a threshold impact velocity do not deform the face sufficiently to engage the deformation limiting member, and impacts of the ball on the face above the threshold impact velocity deform the face sufficiently to engage the deformation limiting member.
According to another aspect, the deformation limiting member extends from an inner surface of the body toward the inner surface of the face.
According to a further aspect, the face includes a face plate connected to a body member forming the body. The body member has a mounting portion, such that the face plate is connected to the mounting portion. In one embodiment, the body member has an opening at a front end thereof, and the mounting portion is positioned around at least a portion of the opening and forms a recessed platform around at least a portion of the opening, such that a peripheral edge of the face plate contacts the recessed platform to connect the face plate to the mounting portion. In another embodiment, the deformation limiting member is connected to the mounting portion and extends from the mounting portion toward the inner surface of the face. In a further embodiment, the mounting portion is connected to the face plate at top and bottom sides of the face plate, with first and second portions of the deformation limiting member extending from the mounting portion at the top and bottom sides, respectively, toward the inner surface of the face.
According to yet another aspect, the face includes a face plate connected to a body member forming the body. The body member has an opening receiving the face plate therein, and the deformation limiting member includes a flange extending inwardly from an inner surface of the body member around at least a portion of the opening.
According to a still further aspect, the deformation limiting member includes a plurality of braces extending inwardly from inner surfaces of the body, with each brace having an end spaced a distance from the inner surface of the face.
Additional aspects of the invention relate to a wood-type golf club head that includes a face having a ball striking surface adapted to impact a golf ball and an inner surface opposite the ball striking surface, and a wood-type body connected to the face and extending rearward from the face, such that the face and the body define an interior cavity and an interior surface surrounding the cavity and further define a volume of at least 400 cc. The head includes a deformation limiting member located behind the face and having a first portion extending from a fixed end at the interior surface proximate a first of the peripheral edges of the face, toward a center of the face, and a second portion extending from a fixed end at the interior surface proximate a second of the peripheral edges of the face, toward the center of the face. The first and second portions of the deformation limiting member each having a free end spaced a distance from the inner surface of the face. The face and the deformation limiting member are adapted such that an impact of the ball on the ball striking surface causes deformation of the face toward the free ends of the first and second portions of the deformation limiting member. When the deformation of the face is sufficient to cause the inner surface of the face to engage at least one of the free ends of the deformation limiting member, the deformation limiting member exerts a force on the face to resist further deformation of the face. Various aspects described above can be incorporated into the head as well.
Further aspects of the invention relate to a golf club head that includes a face member connected to a body member. The face member forms a face having a ball striking surface adapted to impact a ball and an inner surface opposite the ball striking surface. The body member has a front end with an opening receiving the face member therein and a rear end extending rearwardly from the front end to form a body extending rearward from the face. A deformation limiting member extends inwardly from an inner surface of the body member and has an end spaced a distance from the inner surface of the face. The face member and the deformation limiting member are adapted such that an impact of the ball on the ball striking surface causes deformation of the face toward the deformation limiting member. When the deformation of the face is sufficient to cause the inner surface of the face to engage the deformation limiting member, the deformation limiting member exerts a force on the face to resist further deformation of the face.
According to one aspect, the face member is adapted such that impacts of the ball on the face below a threshold impact velocity do not deform the face sufficiently to engage the deformation limiting member, and impacts of the ball on the face above the threshold impact velocity deform the face sufficiently to engage the deformation limiting member.
According to another aspect, the deformation limiting member extends from the inner surface of the body toward a center of the face.
According to a further aspect, the body member has a mounting portion positioned around at least a portion of the opening, wherein the face member is connected to the mounting portion. In one embodiment, the mounting portion forms a recessed platform around at least a portion of the opening, and a peripheral edge of the face member contacts the recessed platform to connect the face plate to the mounting portion. According to another embodiment, the deformation limiting member is connected to the mounting portion and extends from the mounting portion toward the inner surface of the face. In a further embodiment, the mounting portion is connected to the face member at top and bottom sides of the face member, and first and second portions of the deformation limiting member extend from the mounting portion at the top and bottom sides, respectively, toward the inner surface of the face.
According to yet another aspect, the deformation limiting member comprises a flange extending inwardly from the inner surface of the body member around at least a portion of the opening.
Still further aspects of the invention relate to wood-type golf club head that includes a face member and a body member connected to the face member. The face member has a ball striking surface adapted to impact a golf ball and an inner surface opposite the ball striking surface, with the face member being defined by peripheral edges. The body member has a front end with an opening receiving the face member therein and a rear end extending rearwardly from the front end to form a wood-type body extending rearward from the face. The face member and the body member define an interior cavity and an interior surface surrounding the cavity and define a volume of at least 400 cc. The body member further has a mounting portion forming a platform around at least a portion of the opening, where the platform is recessed from the front end of the body member and the peripheral edges of the face plate contact the platform to connect the face plate to the mounting portion. The head also includes deformation limiting member having a fixed end connected to the mounting portion, such that the deformation limiting member extends from the mounting portion toward a center of the face and has a free end spaced a distance from the inner surface of the face. The face member and the deformation limiting member are adapted such that an impact of the ball on the ball striking surface causes deformation of the face toward the deformation limiting member. When the deformation of the face is sufficient to cause the inner surface of the face to engage the deformation limiting member, the deformation limiting member exerts a force on the face to resist further deformation of the face. Various aspects described above can be incorporated into the head as well.
According to one aspect, the mounting portion is connected to the face member at top and bottom sides of the face member, where a first portion of the deformation limiting member extends from the mounting portion at the top side toward the inner surface of the face and a second portion of the deformation limiting member extends from the mounting portion at the bottom side toward the inner surface of the face. In one embodiment, the deformation limiting member includes a flange extending inwardly from the mounting portion around at least a top portion and a bottom portion of the opening, where the flange defines the first portion and the second portion of the deformation limiting member.
Other aspects of the invention relate to a method that includes selecting at least one face member and/or at least one body member, as described above, from a plurality of such members. The face member and body member can then be assembled to produce a head.
Still other aspects of the invention relate to golf clubs that include a golf club head as described above and a shaft connected to the head, or a set of golf clubs including at least one golf club having a head as described above.
Other features and advantages of the invention will be apparent from the following description taken in conjunction with the attached drawings.
To allow for a more full understanding of the present invention, it will now be described by way of example, with reference to the accompanying drawings in which:
It is understood that the relative sizes and thicknesses of the components shown in the figures, including
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” 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, and welding (including brazing, soldering, or the like), where separation of the joined pieces cannot be accomplished without structural damage thereto.
In general, aspects of this invention relate to ball striking devices, such as golf club heads, golf clubs, 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 is a substantially flat surface on one face of the ball striking head. It is understood that some golf clubs or other ball striking devices may have more than one ball striking surface. Some more specific aspects of this invention relate to wood-type golf clubs and golf club heads. Alternately, some aspects of this invention may be practiced with iron-type golf clubs and golf club heads, hybrid clubs, chippers, putters, etc.
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 (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. It is understood that the head may contain components made of several different materials, including carbon-fiber and other composites. Additionally, the components may be formed by various forming methods. For example, metal components (such as 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.
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.
At least some examples of ball striking devices according to the invention relate to golf club head structures, including heads for wood-type golf clubs, such as drivers, fairway woods, etc. Other examples of ball striking devices according to the invention may relate to iron-type golf clubs, such as long iron clubs (e.g., driving irons, zero irons through five irons), short iron clubs (e.g., six irons through pitching wedges, as well as sand wedges, lob wedges, gap wedges, and/or other wedges), as well as hybrid clubs, putters, chippers, and other types of clubs. Such devices may include a one-piece construction or a multiple-piece construction. Example structures of ball striking devices according to this invention will be described in detail below in conjunction with
In the illustrative embodiment illustrated in
The face 112 is located at the front 124 of the head 102, and has a ball striking surface 110 located thereon and an inner surface 111 opposite the ball striking surface 110. The ball striking surface 110 is typically an outer surface of the face 112 configured to face a ball 106 in use, and is adapted to strike the ball when the device 100 is set in motion, such as by swinging. The face 112 is defined by a plurality of peripheral edges, including a top edge 113, a bottom edge 115, a heel edge 117, and a toe edge 119. Additionally, in this embodiment, the face 112 has a plurality of face grooves 121 on the ball striking surface 110, which do not extend across the center of the face 112. In another embodiment, such as a fairway wood head a hybrid wood-type head, the face 112 may have grooves 121 that extend across at least a portion of the center of the face 112.
As shown, the ball striking surface 110 is relatively flat, occupying most of the face 112. For reference purposes, the portion of the face 112 nearest the top face edge 113 and the heel 120 of the head 102 is referred to as the “high-heel area” the portion of the face 112 nearest the top face edge 113 and toe 122 of the head 102 is referred to as the “high-toe area”; the portion of the face 112 nearest the bottom face edge 115 and heel 120 of the head 102 is referred to as the “low-heel area”; and the portion of the face 112 nearest the bottom face edge 115 and toe 122 of the head 102 is referred to as the “low-toe area”. Conceptually, these areas may be recognized and referred to as quadrants of substantially equal size (and/or quadrants extending from a geometric center of the face 112), though not necessarily with symmetrical dimensions. The face 112 may 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 surface 110 may occupy a different proportion of the face 112, or the body 108 may have multiple ball striking surfaces 110 thereon. In the illustrative embodiment shown in
It is understood that the face 112, the body 108, and/or the hosel 109 can be formed as a single piece or as separate pieces that are joined together. For example, in the embodiment illustrated in
In the embodiment illustrated in
The ball striking device 100 may include a shaft 104 connected to or otherwise engaged with the ball striking head 102, as shown in
The shaft 104 may be constructed from one or more of a variety of materials, including metals, ceramics, polymers, composites, or wood. In some illustrative embodiments, the shaft 104, 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 shaft 104 may 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 element 105 may be positioned on the shaft 104 to provide a golfer with a slip resistant surface with which to grasp golf club shaft 104, as shown in
In general, ball striking heads as described herein contain a deformation limiting member 140 that is located behind the face 112 and limits deformation of the face 112 under certain conditions. In one example embodiment, the face 112 and the deformation limiting member 140 are adapted such that an impact of the ball 106 on the ball striking surface 110 causes deformation of the face 112 toward the deformation limiting member 140, and when the deformation of the face 112 is sufficient to cause the inner surface 111 of the face 112 to engage the deformation limiting member 140, the deformation limiting member 140 exerts a force on the face 112 to resist further deformation of the face 112. The degree of deformation of the face 112 can be dependent on several factors, including the swing speed of the head 102. Accordingly, in one embodiment, impacts of the ball 106 on the face 112 below a threshold impact velocity (i.e. swing speed) do not deform the face 112 sufficiently to engage the deformation limiting member 140, and impacts of the ball 106 on the face 112 above the threshold impact velocity can deform the face 112 sufficiently to engage the deformation limiting member 140. The degree of deformation of the face 112 can also depend on other factors, such as the stiffness of the face 112, the mass and flexibility of the ball 106, the location of impact on the face 112, etc. Thus, it is understood that the head 102 may be customized or tuned to different threshold swing speeds, and that external factors (e.g., properties of the ball 106) may cause the face 112 to deform differently.
In one embodiment, such as the head 102 illustrated in
The deformation limiting member 140 may have a different configuration in other embodiments, including the configurations shown in
In one embodiment, the head 102 may have a threshold swing speed, where impacts above the threshold swing speed deform the face 112 sufficiently that the deformation limiting member 140 engages the face as described above, and impacts below the threshold swing speed do not sufficiently deform the face 112 to contact the deformation limiting member 140. For example, the threshold swing speed in one embodiment may be approximately 105 mph, for an impact in the center and/or area of highest response of the face 112. In another embodiment, the threshold swing speed may be approximately 100 mph, and in a further embodiment, the threshold swing speed may be approximately 95 mph. Such threshold swing speeds may depend at least partially on the mass of the object being struck, and it is understood that the threshold swing speed may be different for striking different objects having different masses. In one embodiment, the threshold swing speeds discussed above may be applicable for striking a regulation golf ball 106 having a maximum weight of approximately 1.62 oz. Additional characteristics of the struck object, the face 112, and/or the impact itself may influence the threshold speed. For example, the location of the impact on the face 112, the angle of the face 112 at impact, the flexibility of the object being struck, and any inherent non-linear impact properties of the face 112 and/or the object may affect the threshold swing speed. In one embodiment, the threshold swing speed identified above may be adapted for substantially square impacts with a regulation golf ball 106, at or around the center of the face 112 and/or the area of highest response of the face 112. It is understood that changes in the properties of the face 112, such as the local or overall stiffness of the face 112, which may be dependent on both the modulus and the cross-sectional moment of inertia of the face 112, may raise or lower the threshold swing speed. Additionally, the distance from the inner surface 111 of the face 112 to the deformation limiting member 140 may also affect the threshold velocity, as a deformation limiting member 140 that has a free end 143 spaced farther from the face 112 may require greater impact energy to sufficiently deform the face 112, and vice versa.
As shown in
The face 312 is located at the front 324 of the head 302, and has an outer surface 310, as well as a rear surface 311 located opposite the outer surface 310, which may be considered an inner surface of the face 312. The face 312 is defined by a plurality of peripheral edges, including a top edge 313, a bottom edge 315, a heel edge 317, and a toe edge 319. The face 312 also has a plurality of face grooves 321 on the ball striking surface 310. For reference purposes, the portion of the face 312 nearest the top face edge 313 and the heel 320 of the head 302 is referred to as the “high-heel area”; the portion of the face 312 nearest the top face edge 313 and toe 322 of the head 302 is referred to as the “high-toe area”; the portion of the face 312 nearest the bottom face edge 315 and heel 320 of the head 302 is referred to as the “low-heel area”; and the portion of the face 312 nearest the bottom face edge 315 and toe 322 of the head 302 is referred to as the “low-toe area”. Conceptually, these areas may be recognized and referred to as quadrants of substantially equal size (and/or quadrants extending from a geometric center of the face 312), though not necessarily with symmetrical dimensions. The face 312 may 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. The ball striking surface 310 is inclined (i.e., at a loft angle), to give the ball an appreciable degree of lift and spin when struck. In various embodiments, the ball striking surface 310 may have a different incline or loft angle, to affect the trajectory of the ball. For example, in one embodiment, an iron-type golf club head 302 as shown in
The body 308 of the golf club head 302 may be constructed from a wide variety of different materials, including materials conventionally known and used in the art, such as steel, titanium, aluminum, tungsten, graphite, polymers, or composites, or combinations thereof. Also, if desired, the club head 302 may be made from any number of pieces (e.g., having a separate face plate, etc.) and/or by any construction technique, including, for example, casting, forging, welding, and/or other methods known and used in the art. The face 312 may be constructed using any of the materials described above, as well as any other suitable materials.
It is understood that the face 312, the body 308, and/or the hosel 309 can be formed as a single piece or as separate pieces that are joined together, similarly to the head 102 described above and shown in
In the embodiment illustrated in
The ball striking device 300 may include a shaft 304 connected to or otherwise engaged with the ball striking head 302, as shown in
In the embodiment illustrated in
Several different embodiments have been described above, including the various embodiments of golf clubs 100 and heads 102, 102′, 202, 302 (referred to herein as 102, et seq.) and portions thereof described herein. It is understood that any of the features of these various embodiments may be combined and/or interchanged. For example, as described above, various different combinations of club heads 102, et seq. with differently configured deformation limiting members 140, et seq. may be used, including the configurations described herein, variations or combinations of such configurations, or other configurations. In further embodiments, at least some of the features described herein can be used in connection with other configurations of wood-type clubs, iron-type clubs, other golf clubs, or other types of ball-striking devices.
Heads 102, et seq. incorporating the features disclosed herein may be used as a ball striking device or a part thereof. For example, a golf club 100 as shown in
Additionally, the heads 102, et seq., golf clubs 100, et seq., or other ball striking device may be fitted or customized for a particular user. Such customization is described below with respect to the head 102 of
The ball striking devices and heads therefor as described herein provide many benefits and advantages over existing products. For example, a ball striking head containing a deformation limiting member as described herein can be optimized for a particular swing speed, including lower swing speeds. As described above, many existing golf club heads are optimized for swing speeds that are higher than typical swing speeds for older and/or less experienced golfers. A golf club head as described herein, including a deformation limiting member, can provide improved performance at lower swing speeds, allowing players having low swing speeds to achieve greater ball speeds, while not impeding the ball speed achieved at higher swing speeds. Still other benefits and advantages are readily recognizable to those skilled in the art.
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.
This is a continuation of pending U.S. patent application Ser. No. 15/975,668 filed May 9, 2018, which is a continuation of U.S. patent application Ser. No. 13/907,439, filed May 31, 2013, now U.S. Pat. No. 9,993,699 issued Jun. 12, 2018, which is a non-provisional of and claims priority to U.S. patent application No. 61/653,873, filed May 31, 2012, all of which are incorporated herein by reference in their entirety and made part hereof.
Number | Date | Country | |
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61653873 | May 2012 | US |
Number | Date | Country | |
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Parent | 15975668 | May 2018 | US |
Child | 16688375 | US | |
Parent | 13907439 | May 2013 | US |
Child | 15975668 | US |