Patent Publication Number: US-2022219052-A1

Title: Golf Clubs and Golf Club Heads

Description:
This is a continuation of U.S. patent application Ser. No. 16/908,310 filed Jun. 22, 2020, which is a continuation of U.S. patent application Ser. No. 16/542,647 filed Aug. 16, 2019, now U.S. Pat. No. 10,729,947 issued Aug. 4, 2020, which is a continuation of U.S. patent application Ser. No. 16/107,961 filed Aug. 21, 2018, now U.S. Pat. No. 10,449,426 issued Oct. 22, 2019, which is a continuation of U.S. patent application Ser. No. 14/726,260 filed May 29, 2015, now U.S. Pat. No. 10,130,849 issued Nov. 20, 2018, all of the above reference applications are incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The invention relates generally to ball striking devices, such as golf clubs and golf club heads, utilizing mass damping effects at impact. Certain aspects of this invention relate to golf club heads having a damping member configured to create a mass damping effect upon an impact on the face. 
     BACKGROUND 
     Golf clubs and many other ball striking devices can encounter undesirable effects when the ball being struck impacts the ball striking head away from the optimum location, which may be referred to as an “off-center impact.” In a golf club head, this optimum location is, in many cases, aligned laterally and/or vertically with the center of gravity (CG) of the head. Even slightly off-center impacts can sometimes significantly affect the performance of the head, and can result in reduced velocity and/or energy transfer to the ball, inconsistent ball flight direction and/or spin caused by twisting of the head, increased vibration that can produce undesirable sound and/or feel, and other undesirable effects. Technologies that can reduce or eliminate some or all of these undesirable effects could have great usefulness in golf club heads and other ball striking devices. 
     The present devices and methods are provided to address at least some of 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. 
     BRIEF SUMMARY 
     The following presents a general summary of aspects of the invention in order to provide a basic understanding of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a general form as a prelude to the more detailed description provided below. 
     Aspects of the disclosure relate to ball striking devices, such as golf clubs, with a head that includes a face having a striking surface configured for striking a ball, the face having a heel portion and a toe portion, and a body connected to the face and extending rearwardly from the face, with the body having a crown, a sole, a heel side, and a toe side, such that the face and the body combine to define an enclosed internal cavity. A damping member is connected to the body and includes a post extending inwardly into the cavity from an inner surface of the body, a first arm extending from the post toward the heel side of the body, and a second arm extending from the post toward the toe side of the body. The damping member is configured to produce a mass damping effect upon an impact on the face. 
     According to one aspect, the post acts as a torsion bar, the post is configured to exert at least a counterclockwise torsional force on the face during the impact on the toe portion of the face and to exert at least a clockwise torsional force on the face during the impact on the heel portion of the face, when viewed from above, to create the mass damping effect. 
     According to another aspect, the first arm further includes a first weight member connected to the first arm and the second arm further includes a second weight member connected to the second arm, wherein the first and second weight members have greater densities than the post. 
     According to a further aspect, the head also includes a first abutment member connected to the inner surface of the body and positioned within the cavity adjacent the first arm, with the first abutment member having a resilient material engaging a front surface of the first arm, and a second abutment member connected to the inner surface of the body and positioned within the cavity adjacent the second arm, with the second abutment member having a resilient material engaging a front surface of the second arm. The resilient material of the first abutment member is configured to be compressed by the first arm during the impact on the heel portion of the face, and the resilient material of the second abutment member is configured to be compressed by the second arm during the impact on the toe portion of the face, creating the mass damping effect. In one configuration, the first abutment member further has the resilient material engaging a rear surface of the first arm, and the second abutment member further has the resilient material engaging a rear surface of the second arm. In this configuration, the resilient material of the first abutment member is configured to be compressed by the first arm during the impact on the toe portion of the face, and the resilient material of the second abutment member is configured to be compressed by the second arm during the impact on the heel portion of the face, to further provide the mass damping effect. 
     According to yet another aspect, the post has a fixed end that is fixed to the body and a free end positioned within the rear cavity. In one configuration, the head further includes an abutment member connected to the inner surface of the body opposite the fixed end of the post and positioned within the cavity, with the abutment member having a resilient material engaging the free end of the post. The resilient material of the first abutment member is configured to be compressed by the free end of the post during the impact on the face, to create the mass damping effect. 
     According to a still further aspect, the post has a first fixed end that is fixed to the sole of the body and second fixed end that is fixed to the crown of the body. 
     According to an additional aspect, the post is threaded and the first and second arms are threadably engaged with the post, such that the first and second arms are movable axially along the post by relative rotation between the post and the first and second arms. In one configuration, the post is supported by the body to be freely rotatable and the first and second arms are rotationally fixed, such that rotation of the post is configured to cause axial movement of the first and second arms with respect to the post. In another configuration, the first and second arms are freely rotatable with respect to the post, and the post is rotationally fixed, such that rotation of the first and second arms with respect to the post is configured to cause axial movement of the first and second arms with respect to the post. 
     According to other aspects, the first and second arms may be oriented at approximately 180° to each other, or the first and second arms may be configured such that an angle defined between the first and second arms is adjustable. 
     Additional aspects of the disclosure relate to ball striking devices, such as golf clubs, with a head that includes a face having striking surface configured for striking a ball, with the face having a heel portion and a toe portion, and a body connected to the face and extending rearwardly from the face, with the body having a crown, a sole, a heel side, and a toe side, such that the face and the body combine to define an enclosed internal cavity. A damping member is supported within the cavity, and the damping member includes a first arm positioned on the heel side of the body and a second arm positioned on the toe side of the body. A first abutment member is connected to the inner surface of the body and positioned within the cavity adjacent the first arm, with the first abutment member having a resilient material engaging a front surface of the first arm. A second abutment member is connected to the inner surface of the body and positioned within the cavity adjacent the second arm, with the second abutment member having a resilient material engaging a front surface of the second arm. The damping member is configured to create a mass damping effect upon an impact of the ball on the striking surface, such that the resilient material of the first abutment member is configured to be compressed by the first arm upon the impact on the heel portion of the face and the resilient material of the second abutment member is configured to be compressed by the second arm upon the impact on the toe portion of the face. 
     According to one aspect, the first arm further has a first weight member connected to the first arm and the second arm further has a second weight member connected to the second arm, where the first and second weight members have greater densities than the first and second arms. 
     According to another aspect, the first abutment member further has the resilient material engaging a rear surface of the first arm, and the second abutment member further has the resilient material engaging a rear surface of the second arm. In this configuration, the resilient material of the first abutment member is configured to be compressed by the first arm upon the impact on the toe portion of the face, and the resilient material of the second abutment member is configured to be compressed by the second arm upon the impact on the heel portion of the face, to further create the mass damping effect. 
     According to other aspects, the first and second arms may be oriented at approximately 180° to each other, or the first and second arms may be configured such that an angle defined between the first and second arms is adjustable. 
     According to a further aspect, the damping member further includes a substantially vertical post supported within the cavity, the post having a first end positioned adjacent the crown or sole, such that the post extends into the cavity from the first end. The first and second arms are connected to the post and extend from opposite sides of the post. In one configuration, the first end of the post is fixedly connected to the crown or sole. In another configuration, the head further includes a third abutment member connected to the inner surface of the body and positioned within the cavity adjacent the first end of the post, with the third abutment member having a resilient material engaging front and rear surfaces of the first end of the post. In this configuration, the third abutment member is configured such that the first end of the post is able to compress the resilient material of the third abutment member upon the impact of the ball on the striking surface, to further create the mass damping effect. 
     Further aspects of the disclosure relate to ball striking devices, such as golf clubs, with a head that includes a face having striking surface configured for striking a ball, and a body connected to the face and extending rearwardly from the face, with the body having a crown, a sole, a heel side, and a toe side, such that the face and the body combine to define an enclosed internal cavity. A damping member is connected to the body, with the damping member comprising a post having a first end positioned within the cavity and adjacent the sole and a second end positioned within the cavity and adjacent the crown. A first abutment member is connected to the sole and positioned within the cavity adjacent the first end of the post, and the first abutment member has a resilient material engaging a front surface of the first end of the post. A second abutment member is connected to the crown and positioned within the cavity adjacent the second end of the post, and the second abutment member has a resilient material engaging a front surface of the second end of the post. The damping member is configured to create a mass damping effect upon an impact on the face, such that the first end is configured to compress the resilient material of the first abutment member upon the impact on a lower portion of the face and the second end is configured to compress the resilient material of the second abutment member upon the impact on an upper portion of the face, producing a mass damping effect. 
     According to one aspect, the first abutment member further has the resilient material engaging a rear surface of the first end of the post, and the second abutment member further has the resilient material engaging a rear surface of the second end of the post. In this configuration, the resilient material of the first abutment member is configured to be compressed by the first end of the post upon the impact on the upper portion of the face, and the resilient material of the second abutment member is configured to be compressed by the second end of the post upon the impact on the lower portion of the face, to further produce the mass damping effect. 
     According to another aspect, the damping member further includes a first arm extending from the post toward the heel side of the body and a second arm extending from the post toward the toe side of the body, where the damping member is further configured to further produce the mass damping effect upon the impact on a toe portion or a heel portion of the face. In one configuration, a first weight member is connected to the first arm and a second weight member is connected to the second arm, where the first and second weight members have greater densities than the post. In another configuration, the head further includes a third abutment member connected to the inner surface of the body and positioned within the cavity adjacent the first arm, the third abutment member having a resilient material engaging a front surface of the first arm, and a fourth abutment member connected to the inner surface of the body and positioned within the cavity adjacent the second arm, the fourth abutment member having a resilient material engaging a front surface of the second arm. In this configuration, the resilient material of the third abutment member is configured to be compressed by the first arm upon the impact on the heel portion of the face, and the resilient material of the fourth abutment member is configured to be compressed by the second arm upon the impact on the toe portion of the face to produce the mass damping effect. In a further configuration, the third abutment member may further have the resilient material engaging a rear surface of the first arm, and the fourth abutment member may further have the resilient material engaging a rear surface of the second arm, such that the resilient material of the third abutment member is configured to be compressed by the first arm upon the impact on the toe portion of the face, and such that the resilient material of the fourth abutment member is configured to be compressed by the second arm upon the impact on the heel portion of the face, to further produce the mass damping effect. 
     Other aspects of the invention relate to a golf club or other ball striking device including a head or other ball striking device as described above and a shaft connected to the head/device and configured for gripping by a user. The shaft may be connected to the face member of the head. Aspects of the invention relate to a set of golf clubs including at least one golf club as described above. Yet additional aspects of the invention relate to a method for manufacturing a ball striking device as described above, including connecting a damping member to a club 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. 
    
    
     
       BRIEF DESCRIPTION OF THE 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: 
         FIG. 1  is a top perspective view of one embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 2  is a front view of a ball striking device including the head of  FIG. 1 , in the form of a golf driver; 
         FIG. 3  is a partially exploded and broken away perspective view of the head of  FIG. 1 ; 
         FIG. 4  is a cross-section view taken along lines  4 - 4  of  FIG. 3 ; 
         FIG. 5  is a cross-section view taken along lines  5 - 5  of  FIG. 3 ; 
         FIG. 6  is a partially exploded and broken away perspective view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 7  is a cross-section view taken along lines  7 - 7  of  FIG. 6 ; 
         FIG. 8  is a partially exploded and broken away perspective view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 9  is a cross-section view taken along lines  9 - 9  of  FIG. 8 ; 
         FIG. 10  is a cross-section view taken along lines  10 - 10  of  FIG. 8 ; 
         FIG. 11  is a partially exploded and broken away perspective view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 12  is a cross-section view taken along lines  12 - 12  of  FIG. 11 ; 
         FIG. 13  is a cross-section view taken along lines  13 - 13  of  FIG. 11 ; 
         FIG. 14  is a bottom perspective view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 15  is a partially exploded and broken away perspective view of the head of  FIG. 14 ; 
         FIG. 16  is a cross-section view taken along lines  16 - 16  of  FIG. 15 ; 
         FIG. 17  is a cross-section view taken along lines  17 - 17  of  FIG. 15 ; 
         FIG. 18  is a cross-section view taken along lines  18 - 18  of  FIG. 15 ; 
         FIG. 19  is a cross-section view taken along lines  18 - 18  of  FIG. 15 , illustrating movement of a moveable member within the head; 
         FIG. 20  is a partially exploded and broken away perspective view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 21  is a partially exploded and broken away top view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 22  is a partially exploded and broken away top view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 23  is a partially exploded and broken away perspective view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 24  is a cross-section view taken along lines  24 - 24  of  FIG. 23 ; 
         FIG. 25  is a cross-section view taken along lines  25 - 25  of  FIG. 23 , with a magnified portion to show detail; 
         FIG. 26  is a partially exploded and broken away perspective view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head, with two magnified portions to show detail of two different embodiments of connecting pins; 
         FIG. 27  is a partially exploded and broken away top view of the head of  FIG. 26 , illustrating movement of two arms within an internal cavity of the head; 
         FIG. 28  is a partially exploded and broken away perspective view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 29  is a cross-section view taken along lines  29 - 29  of  FIG. 28 , illustrating movement of a moveable member within the head; 
         FIG. 30  is a cross-section view taken along lines  30 - 30  of  FIG. 28 , illustrating movement of a moveable member within the head; 
         FIG. 31  is a partially exploded and broken away perspective view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 32  is a broken away front view of the head of  FIG. 31 ; 
         FIG. 33  is a broken away front view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 34  is a partially exploded and broken away perspective view of another embodiment of a head for a ball striking device according to aspects of the present disclosure, in the form of a golf driver head; 
         FIG. 35  is an exploded bottom perspective view of the head of  FIG. 34 ; 
         FIG. 36  is a cross-section view taken along lines  36 - 36  of  FIG. 34 ; 
         FIG. 37  is a front view of one embodiment of an adjustable damping member and a removable body panel configured for use with a head for a ball striking device according to aspects of the present disclosure; and 
         FIG. 38  is a front view of another embodiment of an adjustable damping member and a removable body panel configured for use with a head for a ball striking device according to aspects of the present disclosure. 
     
    
    
     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,” 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 (including putters), croquet mallets, polo mallets, baseball or softball bats, cricket bats, tennis rackets, badminton rackets, field hockey sticks, ice hockey sticks, and the like. 
     “Ball striking head” or “head” means the portion of a “ball striking device” that includes and is located immediately adjacent (optionally surrounding) the portion of the ball striking device designed to contact the ball (or other object) in use. In some examples, such as many golf clubs, 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 term “shaft” includes the portion of a ball striking device (if any) that the user holds during a swing of a ball striking device, e.g., a handle. 
     “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. 
     “Approximately” or “about” means within a range of +/−10% of the nominal value modified by such term. 
     In general, aspects of this invention relate to ball striking devices, such as golf club heads, golf clubs, wood-type golf club heads, 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 described herein relate to wood-type golf clubs and golf club heads, including drivers, fairway woods, hybrid-type clubs, although aspects described herein may also be utilized in putters and putter heads, as well as iron-type golf clubs, other types of golf clubs or other ball striking devices, 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, polymer or composite components, such as carbon fiber-polymer composites or other fiber-reinforced polymers (FRPs), can be manufactured by a variety of composite processing techniques, such as prepreg processing, powder-based techniques, injection molding, 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 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  FIGS. 1-36 , which illustrate examples of ball striking devices in the form of golf drivers and will be referred to generally using reference numeral “100.” 
       FIGS. 1-5  illustrate a ball striking device  100  in the form of a golf driver, in accordance with at least some examples of the invention, and  FIGS. 6-36  illustrate various additional embodiments of a golf driver or other wood-type golf club in accordance with aspects of the invention. As shown in  FIGS. 1-5 , the ball striking device  100  includes a ball striking head  102  and a shaft  104  connected to the ball striking head  102  and extending therefrom. The ball striking head  102  of the ball striking device  100  of  FIGS. 1-5  has a face  112  connected to a body  108 , with a hosel  109  extending therefrom. For reference, the head  102  generally has a top or crown  116 , a bottom or sole  118 , a heel or heel side  120  proximate the hosel  109 , a toe or toe side  122  distal from the hosel  109 , a front  124 , and a back or rear  126 . The shape and design of the head  102  may be partially dictated by the intended use of the device  100 . In the club  100  shown in  FIGS. 1-5 , the head  102  has a relatively large volume, as the club  100  is designed for use as a driver, intended to hit a ball (not shown) 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. If instead configured as a fairway wood, the head may have a volume of 120 cc to 230 cc, and if configured as a hybrid club, the head may have a volume of 85 cc to 140 cc. Other appropriate sizes for other club heads may be readily determined by those skilled in the art. 
     In the embodiment illustrated in  FIGS. 1-5 , the head  102  has a hollow structure defining an inner cavity  107  (e.g., defined by the face  112  and the body  108 ). Thus, the head  102  has a plurality of inner surfaces defined therein. In one embodiment, the inner cavity  107  may be filled with air. However, in other embodiments, the head  102  could be filled with another material, such as 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  107  or no inner cavity at all. It is understood that the inner cavity  107  may not be completely enclosed in some embodiments. In the embodiment as illustrated in  FIGS. 1-5 , the body  108  of the head  102  has a rounded rear profile. In other embodiments, the body  108  of the head  102  can have another shape or profile, including a squared or rectangular rear profile, or any of a variety of other shapes. It is understood that such shapes may be configured to distribute weight away from the face  112  and/or the geometric/volumetric center of the head  102 , in order to create a lower center of gravity and/or a higher moment of inertia. The body  108  may be connected to the hosel  109  for connection to a shaft  104 , as described below. 
     The face  112  is located at the front  124  of the head  102 , and has a ball striking surface or striking surface  110  located thereon and an inner surface  111  opposite the ball striking surface  110 , as shown in  FIGS. 4-5 . The ball striking surface  110  is typically an outer surface of the face  112  configured to face a ball 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 peripheral edges or face edges  113 , including a top edge, a bottom edge, a heel edge, and a toe edge. Additionally, in this embodiment, the face  112  has a plurality of face grooves  121  on the ball striking surface  110 . 
     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  113  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  113  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. Additionally, the face  112  may be considered to have a heel portion  125  and a toe portion  127  positioned on opposite sides of the CG of the face  112 , toward the heel  120  and toe  122 , respectively. 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  FIGS. 1-5 , the ball striking surface  110  is inclined slightly (i.e., at a loft angle), to give the ball slight lift and spin when struck. In other illustrative embodiments, the ball striking surface  110  may have a different incline or loft angle, to affect the trajectory of the ball. Additionally, the face  112  may have a variable thickness and/or may have one or more internal or external inserts in some embodiments. 
     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. In one embodiment, the face  112  may be wholly or partially formed by a face member  128  with the body  108  being partially or wholly formed by a body member  129  including one or more separate pieces connected to the face member  128 , as in the embodiment shown in  FIGS. 1-5 , for example. In this embodiment, the body member  129  has a front edge  115  defining an opening  123 , and the face member  128  is in the form of a “cup face” member, i.e., having a wall or walls  117  extending rearwardly from the face  112 , where the front edge  115  of the body member  129  is connected to the wall(s)  117  of the face member  128 . The wall(s)  117  of the face member  128  of  FIGS. 1-5  are shown extending around the entire periphery of the face  112  to form the cup face structure. In other embodiments, the face member  128  may have wall(s)  117  extending around only a portion of the periphery thereof. 
     The body member  129  and the face member  128  are shown as being connected at a butt joint in  FIGS. 1-5 , such as by welding, bonding, or other integral joining technique, fasteners, etc. In other embodiments, different joints may be used to connect the front edge  115  of the body member  129  to the wall(s)  117  of the face member  128 , such as a lap or dovetail joint, or other interlocking and/or overlapping joints. Different joining techniques may be used as well, including various interlocking structures, friction or interference fit connection, etc. In another embodiment, shown in  FIGS. 6-7 , the face member  128  is in the form of a plate member, and the opening  123  defined by the front edge  115  of the body member  129  is dimensioned to receive the face member  128  therein. Additionally, in this embodiment, the front edge  115  of the body member  129  has a recessed flange  119  within the opening  123 , which engages and supports the face member  128  within the opening  123 . The flange  119  may be continuous or discontinuous in various different configurations. The face member  128  in  FIGS. 6-7  may be joined to the body member  129  using any of the joining techniques described herein. The structure and functionality of the head  102  in the embodiment of  FIGS. 6-7  is otherwise similar or identical to that of the embodiment in  FIGS. 1-5  described herein. The structure and connection of the face member  128  and the body member  129  are described in further detail elsewhere herein. 
     In other embodiments, the face member  128  and the body member  129  may be connected in another manner, such as using other known techniques and structures for joining. For example, one or more of a variety of mechanical joining techniques may be used, including fasteners and other releasable mechanical engagement techniques. The hosel  109  in the embodiments of  FIGS. 1-7  is connected directly to the body member  129 , but if desired, the hosel  109  may be connected directly to the face member  128  instead. In further embodiments, the face member  128  and/or the body member  129  may have a different configuration, or the face  112  and the body  108  may be integrally formed, such that separately formed face and body members are not used. In an additional embodiment, the face member  128  and the body member  129  may be connected using a removable connecting structure to permit removal of the face member  128  from the body member  129 , such as to access internal components of the head  102 . Such removable connections may include fasteners, interlocking structures, snap-fit or friction-fit joints, etc. Further, a gasket (not shown) may be included between the face member  128  and the body member  129  in some embodiments. 
     In one embodiment, the face member  128  and the body member  129  may be formed of different materials. For example, one of the face and body members  128 ,  129  may be formed of a metallic material, e.g., a metal, metal alloy, metal matrix composite, etc., and the other may be formed of a polymer-based material (i.e., plastic and/or polymeric material), e.g., various plastics, polymers, and copolymers or other mixes thereof, an FRP or other polymer-matrix composite, etc. In one embodiment, a metallic face member  128  may be joined to a plastic or FRP body member  129 , and in another embodiment, a plastic or FRP face member  128  may be joined to a metallic body member  129 . As another example, the face or body member  128 ,  129  may be formed of a different type of material, e.g., ceramic materials, wood, etc. In further embodiments, the face  112  and/or the body  108  may be defined by multiple members made from different materials. In one embodiment (not shown), the face member  128  may have a face insert made from a different material from the rest of the face member  128 . The body member  129  may similarly have a portion made from a different material in one embodiment. 
     The ball striking device  100  may include a shaft  104  connected to or otherwise engaged with the ball striking head  102 , as shown in  FIG. 2 . The shaft  104  is adapted to be gripped by a user to swing the ball striking device  100  to strike the ball. The shaft  104  can be formed as a separate piece connected to the head  102 , such as by connecting to the hosel  109 , as shown in  FIG. 2 . Any desired hosel and/or head/shaft interconnection structure may be used without departing from this invention, including conventional hosel or other head/shaft interconnection structures as are known and used in the art, or an adjustable, releasable, and/or interchangeable hosel or other head/shaft interconnection structure such as those shown and described in U.S. Patent Application Publication No. 2009/0062029, filed on Aug. 28, 2007, U.S. Patent Application Publication No. 2013/0184098, filed on Oct. 31, 2012, and U.S. Pat. No. 8,533,060, issued Sep. 10, 2013, all of which are incorporated herein by reference in their entireties and made parts hereof. In other illustrative embodiments, at least a portion of the shaft  104  may be an integral piece with the head  102 , and/or the head  102  may not contain a hosel  109  or may contain an internal hosel structure. Still further embodiments are contemplated without departing from the scope of the invention. 
     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  FIG. 2 . The grip element  105  may be attached to the shaft  104  in any desired manner, including in conventional manners known and used in the art (e.g., via adhesives or cements, threads or other mechanical connectors, swedging/swaging, etc.). 
     In general, the head  102  of the ball striking device  100  has a damping member  130  connected to an inner surface  106  defining the cavity  107  and located behind the face  112 . The damping member  130  may be connected to the body  108  and/or the body member  129  and extend into the cavity  107  in one embodiment. In general, the damping member  130  is configured to create a mass damping effect upon impact of the ball on the striking surface  110 , including an off-center impact. The damping member  130  may be connected to the body  108  and/or body member  129  in a number of different configurations that permit the damping member  130  to create the mass damping effect, several of which are described below and shown in the FIGS. For example, the damping member  130  may create a mass damping effect through compression of a resilient material  140  and/or through a “torsion bar” mechanism, according to some embodiments described herein, as well as other structural configurations. In other embodiments, the damping member  130  may be differently configured, and/or the head  102  may contain multiple damping members  130  having similar or different configurations. The damping member  130  in all embodiments may affect or influence the center of gravity (CG) of the head  102 . Additionally, the damping member  130  (and other weighted members described herein) may be made of any of a variety of different materials, which may be selected based on their weight or density, and the damping member  130  in one embodiment is made from a combination of different materials having different densities at selected locations. For example, the damping member  130  may be made from metallic materials of different densities (e.g., aluminum, titanium, stainless steel, tungsten, etc.), polymeric materials that may be doped in some locations with a heavier material (e.g. tungsten), various ceramic materials, and combinations of such materials. The damping member  130  may also include portions that may be more heavily weighted than others, and may include weighted inserts or other inserts. 
     The damping member  130  may have various different dimensions and structural properties in various embodiments. In one embodiment, as illustrated in  FIGS. 1-5 , the damping member  130  may have a configuration that includes an elongated post  131  extending inwardly into the cavity  107  from the inner surface  106  of the body  108 , a first arm  132  extending from the post  131  toward the heel side  120  of the body  108 , and a second arm  133  extending from the post  131  toward the toe side  122  of the body  108 . Each embodiment in  FIGS. 1-38  includes this general configuration, with different structures in different embodiments. 
     In the embodiment shown in  FIGS. 1-5 , the damping member  130  is not rigidly connected to the body  108  at any point, and is supported within the cavity  107  by a plurality of abutment members  150  connected to the inner surface  106  of the body  108 . Generally, the first arm  132  is configured to engage one or more heel abutment members  150 A on the inner surface  106  of the heel  120 , and the second arm  133  is configured to engage one or more toe abutment members  150 B on the inner surface  106  of the toe  122 , so that the arms  132 ,  133  extend from the post  131  laterally across the cavity  107 . Additionally, the post  131  is configured to engage one or more top abutment members  150 C on the inner surface  106  of the crown  116  and one or more bottom abutment members  150 D on the inner surface  106  of the sole  118 , so that the post  131  extends across the cavity  107  in a vertical or substantially vertical direction. The embodiment shown in  FIGS. 1-5  has a pair of bottom abutment members  150 D engaging the front and rear sides of the bottom end  136  of the post  131 , a pair of top abutment members  150 C engaging the front and rear sides of the top end  135  of the post  131 , a pair of heel abutment members  150 A engaging the front and rear sides of the first arm  132 , and a pair of toe abutment members  150 B engaging the front and rear sides of the second arm  133 . It is understood that only one of the front and rear abutment members  150  may be present at each location in one embodiment. The abutment members  150  in this embodiment are connected to the body member  129 , but one or more abutment members  150  may be connected to the face member  128  in another embodiment, depending on the configuration of the head  102  and the positions of the abutment members  150 . It is also understood that the pair of abutment members  150  may be separate members as depicted in  FIGS. 1-5 , or may alternately be integrally formed with each other or otherwise connected to each other to form a single structure in another embodiment. 
     The head  102  may have a resilient material  140  positioned between each abutment member  150  and the portion of the damping member  130  engaging each abutment member  150 . In the embodiment of  FIGS. 1-5 , each of the abutment members  150  has a resilient material  140  on the surface facing the respective arm  132 ,  133 , such that the resilient material  140  is configured to engage the arm  132 ,  133 , and such that the arm  132 ,  133  is configured to compress the resilient material  140  between the arm  132 ,  133  and the abutment member  150 . For example, the first arm  132  is configured to engage and compress the resilient material  140  on the front heel abutment member  150 A on an impact on the heel portion  125  of the face  112 , and the first arm  132  is configured to engage and compress the resilient material  140  on the rear heel abutment member  150 A on an impact on the toe portion  127  of the face  112 . The second arm  132  engages and compresses the resilient material  140  of the toe abutment members  150 B in this same manner, and the top and bottom ends  135 ,  136  of the post  131  engage and compress the resilient material of the top and bottom abutment members  150 C,D in this same manner as well. In the embodiment in  FIGS. 1-5 , as well as the embodiments in  FIGS. 6-19 , each abutment member  150  has the resilient material  140  formed as a separate, integral resilient member connected to the abutment member  150 . In other embodiments, the front and rear abutment members  150  of each pair may include a single piece of resilient material  140  covering both abutment members  150 , or each abutment member  150  may have a greater number of pieces of the resilient material  140 . It is understood that an adhesive or other bonding material may be utilized to connect the resilient material  140  to the abutment member(s)  150 , and that other connection techniques may be used in other embodiments, such as mechanical fasteners, interlocking designs (e.g. dovetail, tab and slot, etc.) and others. 
     In an alternate embodiment, the resilient material  140  may be connected to the damping member  130  in some or all locations, instead of the abutment member(s)  150 , to place the resilient material  140  between the abutment member(s) and the corresponding portion(s) of the damping member  130 . For example, the arms  132 ,  133  and/or the top or bottom ends  135 ,  136  of the post  131  in the head  102  of  FIGS. 1-5  may have the resilient material  140  connected thereto. Thus, in one general embodiment, the head  102  may be configured such that the resilient material  140  is positioned between each abutment member  150  and the corresponding portions of the damping member  130 , and may be connected to at least one of the abutment member and the damping member. In a further embodiment, the head  102  may include one or more abutment members  150  that do not have a resilient material  140 , and the abutment member(s)  150  and/or the arms  132 ,  133  themselves may have sufficient resiliency to achieve mass damping as described herein. 
     The first and second arms  132 ,  133  may include weight members  134  in one embodiment, as illustrated in  FIGS. 3-5 . Each embodiment in  FIGS. 1-38  shows a damping member  130  with arms  132 ,  133  that include weight members  134 , with different structures shown in different embodiments. In general, the weight members  134  achieve the function of distributing the weight of the damping member  130  toward the periphery of the club head  102 . The weight members  134  may have any suitable shape, size, or density, and may be weighted heavier or lighter based on the flexing properties of the resilient material  140  and/or the flexing properties of the post  131 . In other words, heavier weights may be used for a less flexible resilient material  140 , and lighter weights may be used for a more flexible resilient material  140 , in some embodiments. In a post that has a “torsion bar” function as described below, heavier weights may be used for a less flexible post  131 , and lighter weights may be used for a more flexible post  131 , in some embodiments. The weight members  134  in the embodiment of  FIGS. 1-5  are fixedly connected at the ends of the arms  132 ,  133 , and the weight members  134  form the portions of the arms  132 ,  133  that engage the abutment members  150 A,B. In other embodiments, such as in  FIGS. 37-38  (described elsewhere herein in greater detail), the weight members  134  may be removable and interchangeable and/or may be movable along the arms  132 ,  133 . It is understood that these removable, interchangeable, and/or adjustable configurations may be used with any embodiment described herein. Additionally, the post  131  in the club head  102  of  FIGS. 1-5  may include weight members  134  on the top and/or bottom ends  135 ,  136 , similar to the weight members  134  on the arms  132 ,  133 , in another embodiment, such as shown in  FIGS. 31-33 . This periphery-weighted configuration can achieve greater weight distribution around the periphery and increased moment of inertia for the club head  102 , as well as enhancing the capability of the damping member  130  to create a mass damping effect upon impact. Further, the damping member  130  in one embodiment may be positioned so that the CG of the damping member  130  is substantially aligned with the CG of the face  112  and/or the CG of the head  102  overall. For example, in one embodiment, the CG of the damping member  130  is laterally aligned with the CG of the face  112  and/or the CG of the head  102 , and these respective CGs may additionally or alternately be vertically aligned in another embodiment. In the embodiments of  FIGS. 1-38  illustrated herein, the CG of the damping member  130  is at least laterally aligned with the CG of the face  112  and/or the CG of the head  102 , subject to adjustability features as described herein. 
     The damping member  130  (and the weight members  134  thereof) and the abutment members  150  in the embodiment of  FIGS. 1-5  are generally positioned symmetrically with respect to the CG of the head  102  and/or the CG of the face  112 . In other embodiments, the damping member  130  and the abutment members  150  may be positioned asymmetrically with respect to these CGs. Additionally, the damping member  130  and/or the abutment member(s)  150  may be at least partially formed of lightweight materials in one embodiment, such as FRP or other high-strength polymers. Constructing these components of lightweight materials minimizes the proportion of the total weight of the club head  102  that is occupied by these components. The damping member  130  and/or the abutment member(s)  150  may be formed of different materials in other embodiments. In one embodiment, the weight of the damping member  130  may be no more than 7% of the total weight of the head  102 . 
     The resilient material  140  according to one embodiment may be a natural or synthetic rubber material, a polyurethane-based elastomer, or other elastomeric material in one embodiment, but may be a different type of resilient material in another embodiment, including various types of resilient polymers, such as foam materials or other rubber-like materials. Additionally, the resilient material  140  may have resiliency, such that the resilient material  140  compresses in response to an applied force, and returns to its previous (uncompressed) state when the force is removed. The resilient material  140  may further have some viscoelasticity, such that energy may be lost in returning to the uncompressed state. The resilient material  140  may have a strength or hardness that is lower than, and may be significantly lower than, the strength/hardness of the material(s) of the face member  128 , the body member  129 , the abutment member(s)  150 , or other components of the club head  102 . In one embodiment, the resilient material  140  may have a hardness of approximately 70 Shore A to approximately 70 Shore D. The hardness may be determined, for example, by using ASTM D-2240 or another applicable test with a Shore durometer. In some example embodiments, the resilient material  140  may be a polyurethane-based elastomer or an epoxy-based material with a hardness of approximately 70-80 Shore D. Additionally, in one embodiment, the resilient material  140  may have sufficient resiliency to achieve at least half of a mass damping cycle before the ball leaves the face  112  during impact. Further, the resilient material  140  may be any material described in U.S. Patent Application Publication No. 2013/0137533, filed Nov. 30, 2011, which application is incorporated by reference herein in its entirety and made part hereof. 
     The resilient material  140  may have a hardness and/or a modulus that is significantly smaller than the material(s) forming the face  112  and the body  108 . For example, in one embodiment, a resilient material as described herein (e.g., polyurethane or elastomer) may have a modulus (Young&#39;s) of up to 5000 MPa or 1000-5000 MPa, in various embodiments. Metal materials that may be utilized to make the face and/or body in one embodiment (e.g., stainless steel or titanium alloys) may have a modulus of 100-200 GPa. In various embodiments, a metallic material of the face  112  (or face member  128 ) and/or the body  108  (or body member  129 ) may have a modulus that is at least 20× greater, at least 50× greater, or at least 100× greater than the modulus of the resilient material  140 . An FRP or other composite material that may be utilized to make the face  112  and/or body  108  in one embodiment (e.g., carbon fiber reinforced epoxy) may have a modulus of at least 50 GPa. In various embodiments, a composite material of the face  112  (or face member  128 ) and/or the body  108  (or body member  129 ) may have a modulus that is at least 10× greater, at least 20× greater, or at least 50× greater than the modulus of the resilient material  140 . It is understood that the metallic and composite materials described above may form a portion, a majority portion, or the substantial entirety of the face  112  (or face member  128 ) or body  108  (or body member  129 ). Other materials having other moduli may be used in other embodiments. 
     The properties of the resilient material  140 , such as hardness (or modulus) and/or resiliency, may be designed for use in a specific configuration. For example, the hardness and/or resiliency of the resilient material  140  may be designed to ensure that an appropriate degree of mass damping is created, which may be influenced by parameters such as material thickness, mass and mass distribution of various components (including the damping member  130 , the body member  129 , and/or the face member  128 ), intended use of the head  102 , and others. The hardness and resiliency may be achieved through techniques such as material selection and any of a variety of treatments performed on the material that can affect the hardness or resiliency of the resilient material, as discussed elsewhere herein. The hardness and thickness of the resilient material may be tuned to the weight and/or flexural properties of a particular damping member  130 . For example, heavier weights and/or more flexible damping members  130  may require harder resilient material  140 , and lighter weights and/or stiffer damping members  130  may require softer resilient material  140 . Using a thinner resilient material  140  may also necessitate the use of a softer material, and a thicker resilient material  140  may be usable with harder materials. In a configuration where the resilient material  140  is a polyurethane-based material having a hardness of approximately 65 Shore A, the resilient material  140  may have a thickness of approximately 5 mm in one embodiment, or approximately 3 mm in another embodiment, and generally greater than approximately 1 mm (e.g., approximately 1-5 mm or 1-3 mm). In a configuration where the resilient material  140  is an epoxy-based material, the resilient material  140  may have a thickness of approximately 0.5-3.0 mm in one embodiment. 
     The pieces of the resilient material  140  may be formed of multiple components as well, including components having different hardness in different regions, including different hardness distributions. For example, the resilient material  140  may be formed of an exterior shell that has a different (higher or lower) hardness than the interior, such as through being made of a different material (e.g. through co-molding) and/or being treated using a technique to achieve a different hardness. Examples of techniques for achieving a shell with a different hardness include plasma or corona treatment, adhesively bonding a film to the exterior, coating the exterior (such as by spraying or dipping), etc. If a cast or other polyurethane-based material is used, the resilient material  140  may have a thermoplastic polyurethane (TPU) film bonded to the exterior, a higher or lower hardness polyurethane coating applied by spraying or dipping, or another polymer coating (e.g. a thermoset polymer), which may be applied, for example, by dipping the resilient material into an appropriate polymer solution with an appropriate solvent. Additionally, the head  102  may utilize resilient materials  140  with different hardness or compressibility in different locations, which can create different mass damping effects in such different locations. For example, one abutment member  150  may have a resilient material  140  with greater or smaller flexibility and/or thickness than another abutment member  150 , or the front portion of a single abutment member  150  may have a resilient material with greater or smaller flexibility and/or thickness than the rear portion thereof. These resilient materials  140  having different flexibilities may be achieved by techniques described herein, such as treatments, use of different materials, etc. Further, the hardness of the resilient material  140 , or the use of resilient materials  140  having different flexibility in different locations, may be customized for use by a particular golfer or a particular golfer&#39;s hitting pattern and/or to create different mass damping effects. Resilient materials  140  having different thicknesses may be used in different locations for similar purposes. It is understood that if an abutment member  150  is formed of a polymer material, the abutment member  150  and the corresponding resilient material  140  may be formed together through a co-molding process. 
     The damping member  130  may be configured such that a mass damping effect is created during impact, including an off-center impact on the striking surface  110 . The resilient material  140  and the abutment member(s)  150  can serve to enable this mass damping effect between the damping member  130  and the face  112  during impact. Additionally, the damping member  130  may also be configured to resist deflection of the face  112  upon impact of the ball on the striking surface  110 . The stiffness of the damping member  130  and the resiliency and compression of the resilient material  140  permits this mass damping effect to be created by the damping member  130 . As described above, the damping member  130  compresses the resilient material  140 , causing the resilient material  140  and the abutment member(s)  150  to create this mass damping effect. The resilient material  140  may compress and return to its uncompressed, or even beyond its uncompressed state, repeatedly after impact. Each compression-decompression cycle will be generally smaller than a previous cycle, if applicable, as a result of hysteresis losses within the resilient material  140 , resulting in the mass damping effect. The damping member  130  creates this mass damping effect at the abutment members  150 , i.e., at the connection points between the abutment members  150  and the body  108 . This effect is transferred to the face  112  through the connection between the body  108  and the face  112 . 
     For example, in this embodiment, upon an off-center impact of the ball located toward the heel  120  or toe  122 , the face  112  tends to twist and deflect rearwardly at the heel  120  or toe  122 . As the face  112  begins to deflect rearwardly, the mass damping effect created by the damping member  130  resists this deflection, as described above. In the embodiment of  FIGS. 1-5 , on a heel-side impact, at least some of the mass damping effect is created by the first arm  132  of the damping member  130  engaging the front heel abutment member  150 A (and the resilient material  140  thereof) during impact. The first arm  132  of the damping member  130  may resist rearward movement of the heel portion  125  of the face  112 , and the second arm  133  of the damping member  130  may resist forward movement of the toe portion  127  of the face  112  in this situation. Likewise, on a toe-side impact, at least some of the mass damping effect is created by the second arm  133  of the damping member  130  engaging the front toe abutment member  150 B (and the resilient material  140  thereof) during impact. The second arm  133  of the damping member  130  may resist rearward movement of the toe portion  127  of the face  112 , and the first arm  132  of the damping member  130  may resist forward movement of the heel portion  125  of the face  112  in this situation. The arms  132 ,  133  may also engage the resilient material  140  of the rear heel or toe abutment member  150 A,B, to enhance the mass damping effect on a toe side or heel side impact, respectively. It is understood that the forces exerted between the face  112  and the damping member  130  are exerted on the portions of the body  108  located between the face  112  and the abutment member(s)  150 . The actions achieving the mass damping effect occur between the beginning and the end of the impact, which in one embodiment of a golf driver may be between 4-5 ms. 
     As described above, it is understood that the degree of potential moment causing deflection of the face  112  may increase as the impact location diverges from the CG the face  112  and/or the CG of the head  102 . In one embodiment, the mass damping effect created by the damping member  130  may also increase as the impact location diverges from the center of gravity of the face  112 , to provide increased resistance to such deflection of the face  112 . In other words, the mass damping effect created by the damping member  130 , e.g., the force exerted on the abutment member(s)  150  by the damping member  130  through the resilient material  140 , may be incremental and directly relative/proportional to the distance the impact is made from the optimal impact point (e.g. the lateral center point of the striking surface  110  and/or the CGs of the face/head, in exemplary embodiments). Thus, the mass damping effect of the damping member  130  increases incrementally in the direction in which the ball makes contact away from the center of gravity of the head  102 . This mass damping effect can reduce the degree of twisting of the face  112  and keep the face  112  more square upon impacts, including off-center impacts. Additionally, this mass damping effect can minimize energy loss on off-center impacts, resulting in more consistent ball distance on impacts anywhere on the face  112 . 
     In the embodiment of  FIGS. 1-5 , the damping member  130  can also create a mass damping effect on impacts that are above or below the CG of the face  112  and/or the CG of the head  102 , in a mechanism similar to that described above with respect to heel or toe side impacts. For example, during impacts high on the face  112 , the top end  135  of the post  131  may compress the resilient material  140  on the front top abutment member  150 C, creating a mass damping effect as similarly described above. The bottom end  136  of the post  131  may compress the resilient material  140  on the rear bottom abutment member  150 D during this impact as well. As another example, during impacts low on the face  112 , the bottom end  136  of the post  131  may compress the resilient material  140  on the front bottom abutment member  150 D, creating a mass damping effect as similarly described above. The top end  135  of the post  131  may compress the resilient material  140  on the rear top abutment member  150 C during this impact as well. It is understood that the top and/or bottom ends  135 ,  136  of the post  131  in  FIGS. 1-5  may have weight members (not shown) similar to the weight members  134  on the arms  132 ,  133  in any embodiment described herein, in order to enhance this mass damping effect. 
       FIGS. 8-38  illustrate additional embodiments of ball striking heads in the form of a wood-type golf club head  102 , which contains many components, features, and properties that are similar to the features described above with respect to the heads  102  of  FIGS. 1-7 . Description of some such similar or shared components, features, and/or properties that have already been described above may be simplified or eliminated for the sake of brevity in the description below. Thus, the embodiments of  FIGS. 8-38  are generally described herein with respect to the differences that exist between such club heads  102  and the embodiments of  FIGS. 1-7 , and it can be assumed that components, features, and properties that are not described herein with respect to the embodiments in  FIGS. 8-38  may be configured similarly to those described above with respect to  FIGS. 1-7 . For example, it is noted that any of the embodiments of  FIGS. 8-38  may include damping members  130  that are positioned and oriented with respect to the CGs of the head  102  and/or the face  112  in any manner described above with respect to  FIGS. 1-7 . 
     The club head  102  in the embodiment of  FIGS. 8-10  is structurally similar to the club head  102  described above with respect to  FIGS. 1-7 , and generally may include any of the features (including alternate embodiments) described herein with respect to  FIGS. 1-5 . In the embodiment of  FIGS. 8-10 , the head  102  does not have top and bottom abutment members  150 C,D, and the top and bottom ends  135 ,  136  of the post  131  of the damping member  130  are fixed to the inner surfaces  106  on the crown  116  and the sole  118 , respectively. In this configuration, the post  131  is vertical or generally vertical and extends across the cavity  107  as similarly described above. The post  131  may be fixed to the inner surfaces  106  of the body  108  using any connection techniques described herein, or other known connection techniques, as described herein. As shown in  FIGS. 8-10 , the post  131  is connected to the body member  129 , but one or both ends  135 ,  136  of the post  131  may be connected to the face member  128  in another embodiment, depending on the configuration of the head  102  and the position of the damping member  130 . The head  102  in  FIGS. 8-10  includes front and rear heel and toe abutment members  150 A,B with resilient material  140  thereon as described herein with respect to  FIGS. 1-5 . The damping member in this embodiment has arms  132 ,  133  that engage the heel and toe abutment members  150 A,B, with the arms  132 ,  133  having weight members  134  thereon, as also described herein with respect to  FIGS. 1-5 . The abutment members  150  in this embodiment are connected to the body member  129 , but one or both abutment members  150  may be connected to the face member  128  in another embodiment, depending on the configuration of the head  102  and the positions of the abutment members  150 . 
     The damping member  130  in the embodiment of  FIGS. 8-10  is configured such that the post  131  acts as a “torsion bar” to create a mass damping effect upon impact. In other words, the arms  132 ,  133  of the damping member  130  can create the mass damping effect by axial twisting of the post  131 . The resilient material  140  and the abutment member(s)  150  in this embodiment can also combine with the damping member  130  to create a mass damping effect, particularly during off-center impacts toward the heel  120  or toe  122 , as described herein with respect to  FIGS. 1-5 . The torsional force created by the post  131  and the resiliency and compression of the resilient material  140  permits the damping member  130  to create this mass damping effect, through the connections between the post  131  and the body  108  and the engagement of the arms  132 ,  133  with the resilient material  140  of the abutment members  150 . Additionally, the connection points between the post  131  and the body  108  are aligned laterally with the CG of the face  112  and/or the CG of the head  102  in this embodiment. 
     The post  131  connected as shown in  FIGS. 8-10  and described above is capable of exerting a torsional force on the face  112  upon an impact on the striking face  110 . The degree of torsional force of the post  131 , and the resultant degree of mass damping of the damping member  130  depends on many factors. For example, the mechanical properties and configuration of the post  131  affect the degree of mass damping, including the dimensions of the post  131 , such as thickness, cross-sectional area, or moment of area; material properties, such as shear modulus; rotational stiffness (which incorporates both structural and material properties); etc. As another example, the weight distribution and/or moment of inertia of the damping member  130 , particularly relative to the position of the post  131 , may also affect the degree of mass damping, e.g., the weight of the weight members  134  and their distances from the post  131 . The structure and properties of the damping member  130  can therefore be engineered to provide a desired amount of mass damping upon impacts. It is understood that the resilient material  140  and the properties thereof may also affect the degree of mass damping as well, as described above. Due to the combined effects of the resilient material  140  and the post  131  on the mass damping effect of the damping member  130 , a less flexible post  131  may warrant the use of a more flexible resilient material  140 , and vice-versa. 
     The post  131  in the embodiment of  FIGS. 8-10  is rotationally fixed to the head  102  at the top and bottom ends  135 ,  136 . As used herein, two components may be considered to be “rotationally fixed” to each other if no significant rotation of one component with respect to the other can be accomplished without deformation (e.g., bending, twisting, flexing, etc.) of one or both components. It is understood that “deformation” may refer to elastic deformation, plastic deformation, fracture, or any other type of deformation. In various embodiments, this rotational fixing can be accomplished by a variety of different structures, including integral forming; a bonding and/or integral joining technique, such as welding, brazing, soldering, adhesive, etc.; a male/female connection using a friction-fit or interference fit; a male/female connection using a non-circular pin and receiver, various interlocking structures, such as a tab-and-slot structure or a gear tooth structure, various fasteners, as well as combinations of these structures and other structures that can accomplish rotational fixing. 
     In the club head  102  illustrated in  FIGS. 8-10 , during impact, the momentum of the damping member  130  exerts a torsional force on the post  131 , causing the post  131  to exert a torsional force on the face  112  to achieve this mass damping effect. The post  131  exerts the torsional force located at the connection point(s) between the post  131  and the head  102 , i.e., at the connection points between the top and bottom ends  135 ,  136  of the post  131  and the body  108 . This torque exerted on the body  108  is exerted on the face  112  through the connection between the body  108  and the face  112 . As described above, the actions achieving the mass damping effect occur between the beginning and the end of the impact, which in one embodiment of a golf driver may be between 4-5 ms. 
     More specifically, on a heel-side impact in the embodiment of  FIGS. 8-10 , at least some of the mass damping effect of the damping member  130  may be achieved by an initial clockwise (viewed from above) torsional force located at the top and bottom ends  135 ,  136  of the post  131  during impact. Likewise, on a toe-side impact, at least some of the mass damping effect of the damping member  130  may be achieved by an initial counter-clockwise torsional force located at the top and bottom ends  135 ,  136  of the post  131  during impact. This initial torsional force has a moment that is opposed to the moment exerted on the head  102  by the impact of the ball on the face  112 . The initial torsional force exerted by the post  131  may be as described above, however, the torsional force may cycle repeatedly after impact, i.e., cycling between clockwise and counterclockwise forces. Each cycle will be generally smaller than a previous cycle, if applicable, as a result of hysteresis losses within the post, resulting in the mass damping effect. 
     The club head  102  in the embodiment of  FIGS. 11-13  is structurally similar to the club heads  102  described above with respect to  FIGS. 1-10 , and generally may include any of the features (including alternate embodiments) described herein with respect to  FIGS. 1-10 . In the embodiment of  FIGS. 11-13 , the head  102  has a damping member  130  with a post  131  that has the bottom end  136  rotationally fixed to the inner surface  106  of the sole  118 , as in the embodiment of  FIGS. 8-10 , with the top end  135  engaging top abutment members  150 C as in the embodiment of  FIGS. 1-5 . In another embodiment, the top end  135  of the post  131  may be rotationally fixed to the inner surface  106  of the crown  116 , and the bottom end  136  of the post  131  may engage bottom abutment members  150 D as in the embodiment of  FIGS. 1-5 . In this configuration, the post  131  is vertical or generally vertical and extends across the cavity  107  as similarly described above. The head  102  in  FIGS. 11-13  includes front and rear heel and toe abutment members  150 A,B with resilient material  140  thereon as described herein with respect to  FIGS. 1-5 . The damping member  130  in this embodiment has arms  132 ,  133  that engage the heel and toe abutment members  150 A,B, with the arms  132 ,  133  having weight members  134  thereon, as also described herein with respect to  FIGS. 1-5 . The post  131  and the abutment members  150  in this embodiment may be connected to the head  102  in any location or configuration described herein. 
     The damping member  130  in the embodiment of  FIGS. 11-13  is configured such that the post  131  acts as a “torsion bar” to create a mass damping effect upon impact, as described herein with respect to  FIGS. 8-10 . The torque or torsional force generated by twisting of the post  131  is exerted at the connection point between the bottom end  136  of the post  131  and the head  102 . The resilient material  140  and the heel and toe abutment members  150 A,B in this embodiment can also combine with the damping member  130  to create a mass damping effect during off-center impacts toward the heel  120  or toe  122 , as described herein with respect to  FIGS. 1-5 . Further, the resilient material  140  and the top abutment members  150 C can combine with the damping member  130  to create a mass damping effect during high or low impacts, as described herein with respect to  FIGS. 1-5 . 
     The club head  102  in the embodiment of  FIGS. 14-19  is structurally similar to the club heads  102  described above with respect to  FIGS. 1-13 , and generally may include any of the features (including alternate embodiments) described herein with respect to  FIGS. 1-13 . In the embodiment of  FIGS. 14-19 , the head  102  has an adjustable damping member  130  that includes a rotatable post  131  and a moveable member  137  mounted on the post  131 . The moveable member  137  in this embodiment includes a connection member  138  that engages the post  131 , and two arms  132 ,  133  extending outward from the connection member  138  toward the heel  120  and toe  122  of the club head  102 . The arms  132 ,  133  in this embodiment have weight members  134  at or near their ends, as described above with respect to  FIGS. 1-5 . 
     The head  102  in  FIGS. 14-19  includes front and rear heel and toe abutment members  150 A,B with resilient material  140  thereon as described herein with respect to  FIGS. 1-5 . The abutment members  150 A,B in one embodiment are in the form of bracing columns that extend from one or more inner surfaces  106  of the body  108  into the cavity  107 . In the embodiment of  FIGS. 14-19 , the abutment members  150 A,B are in the form of bracing columns connected to the inner surfaces  106  of the crown  116  and the sole  118  and extending in a vertical or substantially vertical manner across the cavity  107 . The abutment members  150 A,B in this embodiment form vertical or substantially vertical tracks  151  in the spaces between the front abutment members  150 A,B and the rear abutment members  150 A,B. The arms  132 ,  133  of the damping member  130  engage the heel and toe abutment members  150 A,B, as also described herein with respect to  FIGS. 1-5 , and portions of the arms  132 ,  133  are received in the tracks  151  and can move along the tracks  151  as the movable member  137  is moved vertically. The weight members  134  are the portions of the arms  132 ,  133  that engage the abutment members  150 A,B and are received in the tracks  151  in the embodiment of  FIGS. 14-19 , but the damping member  130  may be differently configured in other embodiments, such that other portions of the arms  132 ,  133  are received in the tracks  151  and/or engage the abutment members  150 A,B. The engagement between the arms  132 ,  133  and the abutment members  150 A,B also prevent rotation of the moveable member  137  with respect to the face  112 . The connection member  138  and the post  131  are both threaded in a complementary manner. 
     The resilient material  140  and the heel and toe abutment members  150 A,B in this embodiment can combine with the damping member to create a mass damping effect during off-center impacts toward the heel  120  or toe  122 , as described herein with respect to  FIGS. 1-5 . The damping member  130  in this embodiment creates the mass damping effect located at the abutment members  150 A,B, i.e., at the connection points between the abutment members  150  and the crown and sole  116 ,  118 . 
     The post  131  in  FIGS. 14-19  is rotatably mounted to the head  102 , and includes a rotatable base  141  at the bottom end  136  engaging the sole  118  and extending through the wall of the body  108  at the sole  118 , with the post  131  extending upward from the base  141  into the internal cavity  107 . The base  141  in this embodiment is a plate-like structure that has an engagement structure  142  thereon, which is configured to be engaged by a user to manipulate the post  131 , such as shown in  FIG. 14 , which illustrates an implement in the form of a screwdriver  143  engaging the engagement structure  142 . The user may engage the engagement structure  141  with different types of implements, such as sockets, wrenches, Allen wrenches, or other tools; fingers; coins; and other implements capable of rotational locking engagement. The top end  135  of the post  131  is rotatably engaged and supported by a support  144  connected to the inner surface  106  of the crown  116 . The support  144  may also have a resilient material  140  engaging the top end  135  of the post  131  in one embodiment, as shown in  FIG. 16 , in order to function as a front-and-rear pair of abutment members  150 C. If the support  144  is configured to function as abutment members  150 C, the post  131  may also function to create a mass damping effect on high or low impacts, as described above with respect to  FIGS. 1-5 . The post  131  and the abutment members  150  in this embodiment may be connected to the head  102  in any location or configuration described herein. 
     In the configuration in  FIGS. 14-19 , rotation of the moveable member  137  is fixed, and rotation of the post  131  by manipulation of the base  141  causes the moveable member  137  to move axially with respect to the post  131  (i.e., upward or downward) due to the threading engagement between the post  131  and the connection member  138 , similarly to a jackscrew configuration. As the moveable member  137  is moved upward or downward, the arms  132 ,  133  slide vertically within the tracks  151  between the abutment members  150 A,B. The movement of the moveable member  137  is illustrated in  FIGS. 18-19 . The structure of the damping member  130  in  FIGS. 14-19  enables the CG of the head  102  to be raised and lowered from the exterior of the head  102  by raising and lowering the moveable member  137 , while also creating a mass damping effect on off-center impacts. Adjustment of the position of the moveable member  137  may also be used to customize the impact response of the head  102 , by changing the degree of mass damping that occurs during impacts at certain areas. 
     The club heads  102  in the embodiments of  FIGS. 20-22  are structurally similar to the club heads  102  described above with respect to  FIGS. 1-19 , and generally may include any of the features (including alternate embodiments) described herein with respect to  FIGS. 1-19 . In the embodiments of  FIGS. 20-22 , the head  102  has a damping member  130  with a post  131  that has the bottom end  136  rotationally fixed to the inner surface  106  of the sole  118 , as in the embodiment of  FIGS. 8-10 , with the top end  135  being a free end located within the cavity  107 . In each of these configurations, the post  131  is vertical or generally vertical and extends across a portion of the cavity  107 . In other embodiments, the top end  135  of the post  131  may be rotationally fixed to the inner surface  106  of the crown  116 , and the bottom end  136  of the post  131  may be a free end, or the post  131  may extend in a different (non-vertical) direction from another inner surface of the head  102 . The damping member  130  in each of these embodiments has arms  132 ,  133  that extend outwardly from the post  131 , with the arms  132 ,  133  having weight members  134  thereon, as also described herein with respect to  FIGS. 1-5 . The arms  132 ,  133  are connected at the top end  135  of the post  131  in this embodiment. The heads  102  in  FIGS. 20-22  do not include any abutment members  150  as in the embodiments of  FIGS. 1-19 , and the ends of the arms  132 ,  133  are free ends within the cavity  107 . The post  131  in these embodiments may be connected to the head  102  in any location or configuration described herein. 
     The damping member  130  in each of the embodiments of  FIGS. 20-22  is configured such that the post  131  acts as a “torsion bar” to create a mass damping effect upon impact, as described herein with respect to  FIGS. 8-10 . The torsional force generated by twisting of the post  131  is exerted at the connection point between the bottom end  136  of the post  131  and the head  102 . The embodiments of  FIGS. 20-22  all have the arms  132 ,  133  positioned at different angles to each other, which may influence the location of the CG of the head  102 , as well as the mass damping effect upon impact. For example,  FIG. 20  illustrates an embodiment where the arms  132 ,  133  are positioned at a 180° angle to each other and extend laterally in a direction generally parallel to the face  112 . As another example,  FIGS. 21 and 22  illustrate embodiments where the arms  132 ,  133  are positioned at approximately a 90° angle to each other. In  FIG. 21 , the arms  132 ,  133  extend outwardly and toward the face  112  at approximately 45° angles to the front-rear direction, and in  FIG. 22 , the arms  132 ,  133  extend outwardly and away from the face  112  at approximately 45° angles to the front-rear direction. 
     The club heads  102  in the embodiments of  FIGS. 23-27  are structurally similar to the club heads  102  described above with respect to  FIGS. 1-22 , and generally may include any of the features (including alternate embodiments) described herein with respect to  FIGS. 1-22 . In the embodiments of  FIGS. 23-27 , the head  102  has a damping member  130  with a post  131  that has the bottom end  136  rotationally fixed to the inner surface  106  of the sole  118 , as in the embodiment of  FIGS. 8-10 , with the top end  135  being a free end located within the cavity  107 . In each of these configurations, the post  131  is vertical or generally vertical and extends across a portion of the cavity  107 . In other embodiments, the top end  135  of the post  131  may be rotationally fixed to the inner surface  106  of the crown  116 , and the bottom end  136  of the post  131  may be a free end, or the post  131  may extend in a different (non-vertical) direction from another inner surface of the head  102 . The damping member  130  in each of these embodiments has arms  132 ,  133  that extend outwardly from the post  131 , with the arms  132 ,  133  having weight members  134  thereon, as also described herein with respect to  FIGS. 1-5 . The heads  102  in  FIGS. 23-27  do not include any abutment members  150  as in the embodiments of  FIGS. 1-19 , and the ends of the arms  132 ,  133  are free ends within the cavity  107 . The post  131  in these embodiments may be connected to the head  102  in any location or configuration described herein. 
     The damping member  130  in each of the embodiments of  FIGS. 23-27  is configured such that the post  131  acts as a “torsion bar” to create a mass damping effect upon impact, as described herein with respect to  FIGS. 8-10 . The torsional force generated by twisting of the post  131  is exerted at the connection point between the bottom end  136  of the post  131  and the head  102 . The embodiments of  FIGS. 23-27  also include adjustment mechanisms  145  for adjusting the angles of the arms  132 ,  133  with respect to each other and with respect to the post  131 . The adjustment mechanisms  145  in these embodiments are connected to the free end of the post  131 , which is the top end  135  in the embodiments illustrated. Adjustment of the positions of the arms  132 ,  133  permits adjustment of the CG of the head  102 , as well as adjustment of the mass damping effect for impacts on specific areas of the face  112 . 
     In the embodiment of  FIGS. 23-25 , the adjustment mechanism  145  includes a locking teeth arrangement to lock the arms  132 ,  133  in a selected position. In this configuration, each arm  132 ,  133  has a locking member  146  that is connected to the post  131  by receiving the post  131  through an opening. The locking members  146  of the two arms  132 ,  133  have locking teeth that face each other and engage each other to lock the arms  132 ,  133  in position. A spring  147  or other biasing member engages one of the locking members  146  to push the locking members  146  into engagement with each other. The spring  147  may also compress the locking members  146  against a flange  148  on the post  131  to resist rotation of the arms  132 ,  133  with respect to the post  131 , and it is understood that the flange  148  may also include a locking member for rotational locking, such as locking teeth that are complementary with locking teeth on the bottom surface of the second arm  133 , in one embodiment. If the locking members  146  are to be adjusted, the spring  147  can be compressed to separate the locking members  146  and permit rotation of the arms  132 ,  133  with respect to each other and with respect to the post  131 , as shown in  FIG. 24 . Once the arms  132 ,  133  are in the desired positions, the spring  147  and locking members  146  lock the arms  132 ,  133  into position once more. 
     In the embodiment of  FIGS. 26-27 , the adjustment mechanism  145  includes a locking pin arrangement to lock the arms  132 ,  133  in place in a selected position. In this configuration, each arm  132 ,  133  has a locking member  146  that is connected to the post  131  by receiving the post  131  through an opening. The locking members  146  of the two arms  132 ,  133  have a plurality of holes  149  therethrough, and a pin  152  can be received through a hole  149  in each locking member  146  to lock the arms  132 ,  133  in position. The locking members  146  also rest on flange  148  on the post  131 , and it is understood that the flange  148  may also include holes (not shown), such that the pin  152  is received through the holes  149  in the locking members  146  and through a hole in the flange  148 , to lock the arms  132  in position with respect to the post  131 . As shown in  FIG. 26 , the pin  152  may be a straight pin, a threaded pin, or a different type of pin with a different type of locking structure (e.g., a cotter pin or a quarter-turn locking structure). If the locking members  146  are to be adjusted, the pin  152  can be removed to release the locking members  146  and permit rotation of the arms  132 ,  133  with respect to each other and with respect to the post  131 , as shown in  FIG. 27 . Once the arms  132 ,  133  are in the desired positions, the pin  152  can be reinserted to lock the arms  132 ,  133  into position once more. 
     The club head  102  in the embodiment of  FIGS. 28-30  is structurally similar to the club heads  102  described above with respect to  FIGS. 1-27 , and generally may include any of the features (including alternate embodiments) described herein with respect to  FIGS. 1-27 . In the embodiment of  FIGS. 28-30 , the head  102  has an adjustable damping member  130  that includes a fixed post  131  and a moveable member  137  mounted on the post  131 . The bottom end  136  of the post  131  is rotationally fixed to the inner surface  106  of the sole  118 , and the top end  135  is a free end within the cavity  107 . In this configuration, the post  131  is vertical or generally vertical and extends across a portion of the cavity  107 . In other embodiments, the top end  135  of the post  131  may be rotationally fixed to the inner surface  106  of the crown  116 , and the bottom end  136  of the post  131  may be a free end, or the post  131  may be connected to both the crown  116  and the sole  118 , or the post  131  may extend in a different (non-vertical) direction from one or more other inner surfaces of the head  102 . 
     The moveable member  137  in this embodiment includes a connection member  138  that engages the post, and two arms  132 ,  133  extending outward from the connection member  138  toward the heel  120  and toe  122  of the club head  102 . The arms  132 ,  133  in this embodiment have weight members  134  at or near their ends, as described above with respect to  FIGS. 1-5 . The connection member  138  and the post  131  have complementary threading, such that the moveable member  137  can be raised, lowered, and angularly adjusted with respect to the post  131  by rotating the moveable member  137  about the post  131 , as shown in  FIGS. 29-30 . Adjustment of the positions of the arms  132 ,  133  permits adjustment of the CG of the head  102 , as well as adjustment of the mass damping effect for impacts on specific areas of the face  112 . The damping member  130  may further include some structure for holding or locking the moveable member  137  in position with respect to the post  131 , such as a locking structure, or a high-friction threading engagement that is only adjustable through large amounts of torque. 
     The club heads  102  in the embodiments of  FIGS. 31-33  are structurally similar to the club heads  102  described above with respect to  FIGS. 1-30 , and generally may include any of the features (including alternate embodiments) described herein with respect to  FIGS. 1-30 . In the embodiment of  FIGS. 31-32 , the head  102  has a damping member  130  with a post  131  that has the bottom end  136  rotationally fixed to the inner surface  106  of the sole  118 , as in the embodiment of  FIGS. 8-10 , with the top end  135  being a free end within the cavity  107 . The top end  135  of the post  131  extends upwardly above the connection between the post  131  and the arms  132 ,  133 . In the embodiment of  FIG. 33 , the head  102  has a damping member  130  with a post  131  that has the top end  135  rotationally fixed to the inner surface  106  of the crown, as in the embodiment of  FIGS. 8-10 , with the bottom end  136  being a free end within the cavity  107 . The bottom end  136  of the post  131  extends downwardly below the connection between the post  131  and the arms  132 ,  133 . In these configurations, the post  131  is vertical or generally vertical and extends across the cavity  107  as similarly described above. The damping member  130  in each of these embodiments has arms  132 ,  133  that extend outwardly from the post  131  toward the heel  120  and the toe  122 , with the arms  132 ,  133  having weight members  134  thereon, as also described herein with respect to  FIGS. 1-5 . The damping member  130  further has a weight member  134  on the free end of the post  131  in these embodiments, i.e., the top end  135  of the post  131  in the embodiment of  FIGS. 31-32  and the bottom end  136  of the post  131  in the embodiment of  FIG. 33 . The posts  131  these embodiments may be connected to the head  102  in any location or configuration described herein. 
     The damping member  130  in each of the embodiments of  FIGS. 31-33  is configured such that the post  131  acts as a “torsion bar” to create a mass damping effect upon impact, as described herein with respect to  FIGS. 8-10 . The torque or torsional force generated by twisting of the post  131  is exerted at the connection point between the bottom end  136  of the post  131  and the head  102 . Further, the weight member  134  on the free end of the post  131  can serve to create a mass damping effect during high or low impacts, as described herein with respect to  FIGS. 1-5 . 
     The club head  102  in the embodiment of  FIGS. 34-36  includes a damping member  130  that is similar or identical to the damping member  130  in  FIG. 20 , and has a structure and function that are similar or identical to the damping member  130  in  FIG. 20 , including any variations or alternate embodiments. The head  102  in  FIGS. 34-36  also includes a removable body panel  153  forming a portion of the body  108 , where the damping member  130  is mounted to the removable panel  153 . In the embodiment in  FIGS. 34-36 , the damping member  130  is fixedly connected to the removable panel  153 , such that the removable panel  153  and the damping member  130  can be removed and interchanged with a different damping member  130  connected to a different removable panel  153 . In another embodiment, the damping member  130  may be removably connected to the removable panel  153 , permitting the damping member  130  to be interchanged by disconnecting the damping member  130  from the removable panel  153  and connecting a different damping member  130 . Further, the removable panel  153  may be used in connection with an adjustable damping member  130 , as described below with respect to  FIGS. 37-38 . 
     The removable panel  153  in the embodiment of  FIGS. 34-36  forms a portion of the sole  118 , although in other embodiments, the head  102  may include one or more removable panels  153  that may be located in other locations and form portions of different areas of the body  108 . As shown in  FIGS. 34-36 , the body  108  has an opening  154  in the sole  118 , and the removable panel  153  is received in the opening  154  and covers the opening  154 . The removable panel  153  is removably connected to the body  108  by a plurality of removable fasteners  155  (e.g., screws, bolts, etc.) that are received through holes  156  in the removable panel  153  and in corresponding holes  156  in the body  108  around the opening  154 . In other embodiments, the removable panel  153  may be connected to the body  108  by a different removable connecting structure. As illustrated in  FIG. 35 , the club head  102  has a face member  128  and a body member  129 , and the opening  154  is formed entirely within the body member  129 , such that the removable panel  153  is connected to the body member  129 . In an embodiment where the body member  129  is made from a polymer-based material, the body member  129  may have a reinforcing structure around the opening  154 . In other embodiments, the removable panel  153  may be connected at least partially to the face member  128 , depending on the configurations of the face and body members  128 ,  129  and the configuration and location of the removable panel  153 . It is understood that in other embodiments, the head  102  may not have separately identifiable face and body members  128 ,  129 . 
       FIGS. 37-38  illustrate embodiments of adjustable damping members  130  connected to removable body panels  153  as described herein with respect to  FIGS. 34-36 , which may be used with a club head as shown in  FIGS. 34-36  or other embodiments described herein. In the embodiment of  FIG. 37 , the damping member  130  includes a post  131  with the bottom end  136  connected to the removable body panel  153  and threaded arms  132 ,  133  extending outwardly from the top end  135  of the post  131  toward the heel  120  and toe  122 . The arms  132 ,  133  have adjustable weight members  134  connected thereto, with the weight members  134  having threaded holes  159  to receive the arms  132 ,  133  therethrough. The positions of the weight members  134  on the arms  132 ,  133  can be adjusted by rotating the weight members  134  on the threaded arms  132 ,  133  to achieve translational motion. The weight members  134  can also be removed and interchanged by this action as well. In the embodiment of  FIG. 38 , the damping member  130  includes a post  131  with the bottom end  136  connected to the removable body panel  153  and arms  132 ,  133  extending outwardly from the top end  135  of the post  131  toward the heel  120  and toe  122 . The arms  132 ,  133  have tracks  157  formed by elongated openings through the arms  132 ,  133 , and adjustable weight members  134  are connected to the arms  132 ,  133 , with the weight members  134  having fasteners  158  that are received in the tracks  157  to connect the weight members  134  to the arms  132 ,  133 . The positions of the weight members  134  on the arms  132 ,  133  can be adjusted by loosening the fasteners  158  and sliding the weight members  134  along the tracks  157 , then tightening the fasteners  158  in the desired positions. The weight members  134  can also be removed and interchanged as well, by removing the fasteners  158  and reconnecting them to a different weight member  134 . 
     The damping members  130  in  FIGS. 37-38  or other adjustable damping members  130  may be located, structured, and oriented differently, as described elsewhere herein. The damping members  130  in  FIGS. 37-38  may be fixedly or removably connected to the removable panel  153 , as described above with respect to  FIGS. 34-36 . It is understood that other adjustable damping members  130 , including any of the other internally adjustable mechanisms disclosed herein, such as the embodiments in  FIGS. 23-30 , may include a configuration with a removable body panel  153  as illustrated in  FIGS. 34-38 , or a different structure for providing access to the cavity  107 , such as a removable face  112  as discussed elsewhere herein, or a different removable portion of the head  102 . The adjustable damping member  130  may be directly connected to the removable panel  153  or connected elsewhere within the cavity  107 . The removable panel  153  may be removed to provide access to the damping member  130  for adjustment thereof. Such damping members  130  may be fixedly or removably connected to the removable panel  153 , as described above with respect to  FIGS. 34-36 . 
     It is understood that any of the embodiments of ball striking devices  100 , heads  102 , damping members  130 , and other components described herein may include any of the features described herein with respect to other embodiments described herein, including structural features, functional features, and/or properties, unless otherwise noted. It is understood that the specific sizes, shapes, orientations, and locations of various components of the ball striking devices  100  and heads  102  described herein are simply examples, and that any of these features or properties may be altered in other embodiments. In particular, any of the damping members  130  or structures shown and described herein may be used in connection with any other embodiment shown herein. For example, various configurations of adjustable mechanisms for the damping members  130  may be used simultaneously in some embodiments. 
     Heads  102  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  FIG. 2  may be manufactured by attaching a shaft or handle  104  to a head that is provided, such as the head  102  as described above. As another example, a golf club  100  as shown in  FIG. 2  may be manufactured by attaching damping member  130  to club head  102  or body member  129  that is provided, and connecting a face member  128  to the body member  129 . “Providing” the head, as used herein, refers broadly to making an article available or accessible for future actions to be performed on the article, and does not connote that the party providing the article has manufactured, produced, or supplied the article or that the party providing the article has ownership or control of the article. In other embodiments, different types of ball striking devices can be manufactured according to the principles described herein. In one embodiment, a set of golf clubs can be manufactured, where at least one of the clubs has a head according to one or more embodiments described herein. Such a set may include at least one wood-type club, at least one iron-type club, and/or at least one putter. For example, a set may include one or more wood-type golf clubs and one or more iron-type golf clubs, which may have different loft angles, as well as one or more putters, with one or more clubs having a head  102  as described above and shown in  FIGS. 1-38 . Multiple clubs in the set may have damping members  130  that may be slightly different in shape, size, location, orientation, etc., based on the loft angle of the club. The various clubs may also have an added weight amount or weight distribution (including CG location) that may be different based on characteristics such as the type and loft angle of the club. 
     Different damping members  130  and different locations, orientations, and connections thereof, may produce different mass damping effects upon impacts on the striking surface  110 , including off-center impacts. Additionally, different damping members  130  and different locations, orientations, and connections thereof, may produce different effects depending on the location of the ball impact on the face  112 . Accordingly, one or more clubs can be customized for a particular user by providing a club with a head as described above, with a damping member  130  that is configured in at least one of its shape, size, location, orientation, etc., based on a hitting characteristic of the user, such as a typical hitting pattern or swing speed. Customization may also include adding or adjusting weighting according to the characteristics of the damping member  130  and the hitting characteristic(s) of the user. Several different adjustable and/or interchangeable damping members  130  as described herein can permit such customization by an end user and/or a golf shop. Still further embodiments and variations are possible, including further techniques for customization. 
     The ball striking devices described herein may be used by a user to strike a ball or other object, such as by swinging or otherwise moving the head  102  to strike the ball on the striking surface  110  of the face  112 . During the striking action, the face  112  impacts the ball, and one or more damping members  130  may create a mass damping effect during the impact, in any manner described above. In one embodiment, the damping member(s)  130  may create an incrementally greater mass damping effect for impacts that are farther from the desired impact point (e.g. the CG). As described below, the devices described herein, when used in this or a comparable method, may assist the user in achieving more consistent accuracy and distance of ball travel, as compared to other ball striking devices. 
     The various embodiments of ball striking heads with damping members described herein can provide mass damping effects upon impacts on the striking face, which can assist in keeping the striking face more square with the ball, particularly on off-center impacts, which can in turn provide more accurate ball direction. Additionally, the mass damping effect of the damping member can reduce or minimize energy loss on off-center impacts, creating more consistent ball speed and distance. The mass damping effect may be incremental based on the distance of the impact away from the desired or optimal impact point. Further, the resilient material may achieve some energy absorption or damping on center impacts (e.g. aligned with the center point and/or the CG of the face). As a result of the reduced energy loss on off-center hits, reduced twisting of the face on off-center hits, and/or energy absorption on center hits that can be achieved by the heads as described above, greater consistency in both lateral dispersion and distance dispersion can be achieved as compared to typical ball striking heads of the same type, with impacts at various locations on the face. The ball striking heads described herein can also provide dissipation of impact energy through the resilient material, which can reduce vibration of the club head and may improve feel for the user. Still further, the connection members can be used to control the weighting of the club head and/or the damping member. Other benefits can be recognized and appreciated by 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.