Abstract:
The present invention comprises a golf club head comprising a body having a crown, a sole, a front wall and a hosel, wherein the body defines a hollow interior. The golf club head further comprises a center of gravity adjustment assembly wherein the center of gravity adjustment assembly is positioned within the hollow interior of the body, and allows the center of gravity of the golf club head to be adjusted by at least 0.050 inch, preferably along a vertical axis.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 14/159,262, filed on Jan. 20, 2014, which claims priority to U.S. Provisional Patent Application No. 61/886,473, filed on Oct. 3, 2013, and is a continuation-in-part of U.S. patent application Ser. No. 14/039,102, filed on Sep. 27, 2013, and issued on Sep. 16, 2014, as U.S. Pat. No. 8,834,294, which is a continuation of U.S. patent application Ser. No. 13/797,404, filed on Mar. 12, 2013, which claims priority to U.S. Provisional Patent Application No. 61/657,247, filed on Jun. 8, 2012, U.S. Provisional Patent Application No. 61/665,203 filed on Jun. 27, 2012, and U.S. Provisional Patent Application No. 61/684,079 filed on Aug. 16, 2012, the disclosure of each of which is hereby incorporated by reference in its entirety herein. U.S. patent application Ser. No. 14/159,262 also is a continuation in part of U.S. patent application Ser. No. 13/906,572, filed on May 31, 2013, and issued on Feb. 17, 2015, as U.S. Pat. No. 8,956,244, the disclosure of which is also hereby incorporated by reference in its entirety herein. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a golf club head comprising a center of gravity height adjustability assembly. 
     2. Description of the Related Art 
     The prior art discloses various designs with center of gravity adjustments to improve golf club performance, but fails to provide designs that efficiently alter center of gravity parameters while at the same time contributing to an improved impact event with the golf ball. 
     The United States Golf Association (USGA) has increasingly limited the performance innovations of golf clubs, particularly drivers. Recently, the USGA has limited the volume, dimensions of the head, such as length, width, and height, face compliance, inertia of driver heads and overall club length. Current methods previously used to improve the performance of a driver have been curtailed by limitations on design parameters set by the USGA. An area of driver performance improvement that exists, as of this date, is the potential to adjust the height of the center of gravity. A change in height of the center of gravity changes the amount of backspin provided with a given impact. A higher center of gravity increases spin, while a lower center of gravity decreases spin. 
     The recent past has shown that driver designs have trended to include characteristics to increase the driver&#39;s inertia values to help off-center hits go farther and straighter. Driver designs have also recently included larger faces, which may help the driver deliver better feeling shots as well as shots that have higher ball speeds if hit away from the face center. However, these recent trends may also be detrimental to the driver&#39;s performance due to the head speed reductions that these design features introduce due to the larger geometries. The design of the present invention allows for the higher inertias and robust face design of current drivers while at the same time providing center of gravity is adjustability. 
     BRIEF SUMMARY OF THE INVENTION 
     One purpose of this invention is to effectively incorporate several design features in the golf club head that will enable both adjustment and optimization of the height of the center of gravity. Another object of the present invention is an adjustable weighting feature for vertical center of gravity control which is entirely concealed from view at address. To improve achieve these goals, a golf club head with an internal center of gravity height adjustment assembly is provided, which affects the moment of inertia and ultimately the forgiveness of the golf club head. 
     One aspect of the golf club head of the present invention comprises a body having a crown, a sole, a face and a hosel, wherein the body defines a hollow interior, and a center of gravity height adjustment assembly that is positioned within the hollow interior of the body. Preferably, the location of the center of gravity of the golf club head can be adjusted by 0.050-0.100 inch along any axis, but preferably along a vertical Z axis. 
     Another aspect of the present invention is a golf club head comprising a face, a crown, a sole, a hollow tube, a cap screw, and a cartridge comprising a first material having a first specific gravity and a second material having a second specific gravity that is at least three times the value of the first specific gravity, wherein the tube is disposed within a hollow interior of the golf club head and extends from the crown to the sole, wherein the cartridge is sized to fit within the tube, wherein the tube is accessible via an opening in one of the crown and the sole, and wherein changing the orientation of the carrier within the tube changes the location of the golf club head&#39;s center of gravity along a vertical Z axis. In some embodiments, the first material may be selected from the group consisting of a glass filled epoxy, a glass filled polyester, and a glass-filled nylon, and the second material may be tungsten. In another embodiment, the cap screw may comprise external threads, the opening may comprise internal threads, and the cap screw may be sized to fit within the opening such that the external threads engage with the internal threads. In another embodiment, the cap screw may comprise a plurality of cutouts. 
     In other embodiments, the cartridge may comprise a first end and a second end, and each of the first and second ends may have a shape selected from the group consisting of conically tapered, rounded tapered, and circular. In some further embodiments, the second material may be disposed at the first end, such that the first end is heavier than the second end. In another embodiment, the first end may comprise a first color, and the second end may comprise a second, different color. In another embodiment, the cap screw may comprise a plurality of cutouts, and a portion of the first end or the second end of the cartridge may be visible through the cutouts. 
     In still other embodiments, the crown may comprise an edge support structure sized to receive an end of the hollow tube. In another embodiment, the face may have a frequency of 3000 to 4010 Hz, and the sole may have a frequency of 2500 to 3100 Hz. In another embodiment, the cartridge may be compressed between the crown and the sole, and the tube may be in tension between the crown and the sole. In a further embodiment, the cap screw may place a compression load on the cartridge that exceeds 50 lbs. In another embodiment, the golf club head may further comprise a first cartridge cap comprising a first color and a second cartridge cap comprising a second color, the first cartridge cap may be affixed to the first end of the cartridge, the second cartridge cap may be affixed to the second end of the cartridge, and the first color may be different from the second color. In a further embodiment, the cap screw may comprise a plurality of cutouts, and a portion of the first cartridge cap or the second cartridge cap may be visible through the cutouts. 
     Another aspect of the present invention is a golf club head comprising a body comprising a face, a sole, a rear portion, and a hollow interior, and a hollow tube, wherein the hollow tube is disposed within the hollow interior, and wherein the golf club exhibits one distinguished sound peak that has a frequency of at least 3000 Hz and an amplitude that is at least 8 decibels greater than any other sound peak. In some embodiments, the hollow tube may be disposed closer to the face than to the rear portion. In other embodiments, the face may have a frequency of 3000 to 4010 Hz, and the sole may have a frequency of 2500 to 3100 Hz. In another embodiment, the hollow tube may not extend between the crown and the sole. 
     Yet another aspect of the present invention is a driver-type golf club head comprising a metal body comprising a face and a sole, a composite crown, a hollow tube, a cap screw, and a cartridge comprising a first material having a first specific gravity and a second material having a second specific gravity that is at least three times the value of the first specific gravity, wherein the tube is disposed within a hollow interior of the golf club head, wherein the cartridge is sized to fit within the tube, wherein the cap screw places a compression load on the cartridge that exceeds 50 lbs, and wherein changing the orientation of the carrier within the tube changes the location of the golf club head&#39;s center of gravity by at least 0.050 inch. 
     Another aspect of the present invention is a golf club head comprising a body comprising a face, a sole, and an interior cavity, and an adjustable cartridge that can be removably affixed in the interior cavity in more than one orientation, wherein a distance between a center of gravity of the cartridge and a geometric centroid of the cartridge is defined as ½D, wherein a weight of the cartridge is defined as M T , wherein the combined weight of the body and the cartridge is defined as M, and wherein D≧0.065(1+M/M T ). 
     Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a top perspective view of a golf club head according to the present invention. 
         FIG. 2A  is a cross sectional view of the golf club head shown in  FIG. 1  along lines  2 - 2 , without a cartridge in the tube. 
         FIG. 2B  is a cross sectional view of the golf club head shown in  FIG. 1  along lines  2 - 2 , with a cartridge in the tube. 
         FIGS. 3A, 3B, and 3C  are cross sectional views of different cartridges that may be used with the golf club head of the present invention. 
         FIG. 4  is a cross-sectional view of another cartridge engaged with the golf club of the present invention that illustrates the forces placed on the tube and cartridge. 
         FIG. 5  is an enlarged view of the circled portion in  FIG. 2B . 
         FIG. 6  is a top plan view of a screw cap according to one embodiment of the present invention. 
         FIG. 7  is a cross-sectional view of the screw cap shown in  FIG. 6  along lines  7 - 7 . 
         FIGS. 8A and 8B  are rear and front perspective views of the screw cap shown in  FIG. 6 . 
         FIGS. 9A, 9B, and 9C  are side plan, top plan, and cross-sectional views of a cartridge cap according to one embodiment of the present invention. 
         FIG. 10  is a top plan view of the screw cap shown in  FIG. 6  engaged with the cartridge cap shown in  FIG. 9A . 
         FIG. 11  is a cross sectional view of the screw cap and cartridge cap shown in  FIG. 10  along lines  11 - 11 . 
         FIG. 12  is a sole perspective view of the golf club head shown in  FIG. 1 . 
         FIG. 13  is a top perspective view of the golf club head shown in  FIG. 1  without its crown. 
         FIG. 14  is a side perspective view of the center of gravity height adjustment assembly of the present invention comprising a tube and a cartridge wherein the distance from the midpoint of the tube to the center of gravity is shown. 
         FIG. 15  is a plan view of an inner surface of the crown of the golf club head shown in  FIG. 1 . 
         FIG. 16  is a chart comparing sound results of the preferred embodiment of the present invention with two other adjustable weight drivers that do not include the center of gravity adjustment assembly of the present invention. 
         FIG. 17  is a transparent, top perspective view of an alternative embodiment of the golf club head of the present invention. 
         FIG. 18  is a transparent, top perspective view of an alternative embodiment of the golf club head of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A preferred embodiment of the golf club head  10  of the present invention is shown in  FIGS. 1-2A, 2B, 12, and 13 . The golf club head  10  includes a crown  30 , sole  40 , face  50 , adjustable hosel  60 , and interior cavity  70 , and a center of gravity height adjustment assembly  100  positioned within the interior cavity  70  and completely obscured from view when the golf club head  10  is viewed from above and at address. As shown in  FIGS. 2A and 2B , the center of gravity height adjustment assembly  100  comprises a hollow tube  110  and a removable cartridge  120 . The tube  110  preferably is composed of a carbon composite material, but in alternative embodiments may be composed of Kevlar, fiberglass, plastic, and/or glass-filled plastic (including glass-filled nylon and polycarbonate), and has an extremely low weight, preferably under 5 grams, and more preferably approximately 2 grams. The tube  110  extends from the crown  30  to the sole  40 , has a length of less than 3.8 inches, and preferably is accessed via an opening  45  in the sole  40 , but in alternative embodiments may be accessible via the crown  30  as well as, or instead of, the sole  40 . The center of gravity height adjustment assembly  100  is disposed closer to the face  50  than the rearmost portion  55  of the golf club head  10 . 
     The cartridge  120  is sized to fit snugly within the tube  110 , and is composed of at least two different materials. The first material  122  preferably is a polymer material, such as urethane, or more preferably a glass-filled plastic, nylon, or epoxy, while the second material  124 , which preferably is a tungsten alloy, has a specific gravity that is at least three times greater than the specific gravity of the first material  122 . As shown in  FIG. 2B , the second material  124  preferably is provided in the form of a slug  124 , which is disposed at a first end  121  of the cartridge  120  such that the cartridge  120  has a heavy side  128  and a light side  129 . The slug  124  includes a tapered end  125  that has the same dimensions as the second end  123  of the cartridge  120 , which is also tapered. The tapering on the second end  123  of the cartridge  120  can be provided by a separate cartridge cover  126 , as shown in  FIG. 4 , but is preferably integrally formed with the first material of the cartridge  120 . While the slug  124  and cartridge  120  ends  125 ,  123  are preferably sharply conically tapered as shown in  FIGS. 2B and 3A , they may have rounded tapering as shown in  FIG. 3B , or be circular as shown in  FIG. 3C . 
     When the cartridge  120  is fully inserted into the tube  110 , it is retained therein with a cap screw  130 . The opening  45  in the sole  40  comprises internal threads  46 , and the cap screw  130  comprises external threads  132  that mate with the internal threads  46  of the opening  45  in the sole  40 . When the cap screw  130  is fully screwed into the opening, the inner surface  134  of the cap screw  130  abuts whichever end  123 ,  125  of the cartridge  120  is proximate the sole  40  and presses the cartridge  120  against the interior surface  32  of the crown  30 . Therefore, the cartridge  120  is placed in compression when it is properly disposed in the tube  110  and when the cap screw  130  is torqued with a wrench or other such tool. The cap screw  130  preferably places a compression load on the cartridge  120  that exceeds 50 lbs. In contrast, the tube  110  preferably is slightly shorter in length than the distance between the crown  30  and the sole  40 , such that the tube  110  is in tension, as shown in  FIG. 4 . 
     In addition to providing the function of trapping and compressing the cartridge  120  within the tube  110 , the cap screw  130  of the preferred embodiment also includes a window feature that allows a user to view the orientation of the cartridge  120  within the tube  110  without having to remove the cap screw  130  and the cartridge  120  from the golf club head  10 . As shown in  FIGS. 5-8B , the cap screw  130  includes cutouts  131 ,  133 ,  135  in the cap screw  130  that may be filled in with a translucent material such as glass or plastic or, in the preferred embodiment, be left open to reduce the overall weight of the golf club head  10 . The cartridge ends  123 ,  125  preferably are painted different colors or are marked to indicate orientation, such that when a user looks at the cap screw  130 , he or she can see the colors or markings through one or more of the cutouts  131 ,  133 ,  135  and infer the orientation of the cartridge  120  within the tube  110 . 
     In another embodiment, an additional cartridge cap  140 , an example of which is shown in  FIGS. 9A-9C , may be affixed to both ends  123 ,  125  of the cartridge  120 . This cartridge cap  140  includes a cavity  145  to receive the ends  123 ,  125  of the cartridge  120 , and projections  141 ,  142 ,  142  that extend into the cutouts  131 ,  133 ,  135  of the cap screw  130  when these two parts  130 ,  140  are engaged with one another, as shown in  FIGS. 10 and 11 , thus closing the cutouts  131 ,  133 ,  135  off and preventing debris from entering the cap screw  130  when the golf club head  10  is in use. Each cartridge cap  140  preferably is painted a different color so that a user can immediately determine, upon looking at the cap screw/cartridge cap  130 ,  140  combination, how the cartridge  120  is oriented within the tube  110 . 
     In another embodiment, shown in  FIG. 12 , the cap screw  130  is encircled by a separate sole plate  150 , which preferably is attached to the sole  40  of the golf club head  10  beneath the center of gravity height adjustment assembly  100 . In some embodiments, this sole plate  150  includes an uneven surface for the purpose of adjusting the face angle of the golf club head  10 . 
     As shown in  FIGS. 12 and 13 , the preferred embodiment of the present invention includes at least two weight ports  160 ,  170 , one on each side of the center of gravity adjustment assembly  100 , which are sized to receive removable weights  165 ,  175 . Alternative embodiments may include additional weight ports disposed in the crown  30 , sole  40 , or ribbon/skirt area (not shown) of the golf club head. 
     In the preferred embodiment, the golf club head  10  and cartridge  120  have a mass M, the cartridge  120  has a length L and a mass M T , the distance from the midpoint of the length L to a center of gravity  200  of the cartridge when the cartridge  120  is disposed within a club head  10  is defined as ½D as shown in  FIG. 14 , and the golf club head  10  satisfies the equation D≧0.065(1+M/M T ). In other embodiments, the cartridge  120  can be placed or affixed to the golf club head  10  at more than one orientation and has a distance between its geometric centroid and its center of gravity  200  of ½D, and when combined with a golf club head  10  satisfies the equation D≧0.065(1+M/M T ) in which the M is mass of the golf club head  10  and cartridge  120  and M T  is the mass of the cartridge  120 . 
     In the preferred embodiment disclosed herein, the interior surface  32  of the crown  30  includes a ring-shaped edge support structure  35  to hold the weighting system. This edge support structure  35  preferably is integrally molded from the crown  30  parent material, which preferably is a composite, but may in alternative embodiments be secondarily bonded to the crown  30 . The edge support structure  35  preferably includes two ribs  37 ,  38  with a width of approximately 0.090 inch, a length of 0.407 inch, and a height of 0.236 inch, and serves to increase stiffness of the crown  30  to counteract the mass effect of the center of gravity height adjustment assembly  100 , thus mitigating effects on vibrational behavior. In this manner the edge support structures  35  serve two functional roles; stiffener and tube  110  holder. 
     The edge support structure  35  also affects the sound of the golf club head  10  when it impacts a golf ball, as do other weights that are affixed to the golf club head  10 . In particular, varying the amount of weight in the crown  30  and sole  40  has an effect on driver sound at impact. A relatively flexible weight will mass load the crown, thus affecting vibration modes with significant crown participation. This effect can be mitigated by the use of the edge support structure  35  and matching the stiffness of the center of gravity height adjustment assembly  100  to the local crown  30  structure. 
     The center of gravity adjustment height assembly  100  beneficially affects the sound of the golf club head  10 . The presence of the center of gravity adjustment assembly  100 , and particularly the tube  110 , has a positive effect on the sound and feel of the golf club head  10  during performance. The tube  110  also increases the stiffness of the sole  40 , and thus reduces the sound made by the sole  40  when the golf club head  10  strikes a golf ball, particularly when the tube  110  is disposed proximate the face  50  of the golf club head  10  like in the preferred embodiment. The sole  40  has a sound mode that is split into a higher frequency mode and a lower frequency mode, both of which have lower amplitudes when a tube  110  is located closer to the face  50  than to the rearmost portion  55  of the golf club head  10  as shown in  FIGS. 2A and 2B . Tables 1 and 2 show sound measurements taken at three points on a traditional golf club head and the preferred embodiment of the golf club head  10 . 
     
       
         
               
               
             
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
             
             
               
                   
                   
               
               
                   
                 MODE 
               
             
          
           
               
                   
                 sole 
                   
                 face 
               
               
                   
                   
               
             
          
           
               
                 Traditional Golf 
                   
                   
                   
                   
                   
                   
               
               
                 Club Head 
               
               
                 frequency (Hz) 
                   
                   
                 A 
                 2810 
                 B 
                 3940 (baseline) 
               
               
                 Amplitude (dB) 
                   
                   
                   
                 109 
                   
                  104 (baseline) 
               
               
                 Preferred Embodiment 
               
               
                 frequency (Hz) 
                 1 
                 2520 
                 2 
                 3100 
                 3 
                 4010 
               
               
                 Amplitude (dB) 
                   
                 96.1 
                   
                 97.9 
                   
                 102 
               
               
                   
               
             
          
         
       
     
     
       
         
               
               
             
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 2 
               
             
             
               
                   
                   
               
               
                   
                 MODE 
               
             
          
           
               
                   
                 sole 
                   
                 face 
               
               
                   
                   
               
             
          
           
               
                 Traditional Golf 
                   
                   
                   
                   
                   
                   
               
               
                 Club Head 
               
               
                 frequency (Hz) 
                   
                   
                 A 
                 71% 
                 B 
                 100% (baseline) 
               
               
                 Amplitude (dB) 
                   
                   
                   
                 105%  
                   
                 100% (baseline) 
               
               
                 Preferred Embodiment 
               
               
                 frequency (Hz) 
                 1 
                 64% 
                 2 
                 79% 
                 3 
                 102%  
               
               
                 Amplitude (dB) 
                   
                 92% 
                   
                 94% 
                   
                 98% 
               
               
                   
               
             
          
         
       
     
     As shown in Tables 1 and 2, the center of gravity height adjustment assembly  100  included in the preferred embodiment minimizes amplitude (dB) of the sole  40  compared to the traditional golf club head construction, while keeping the face  50  amplitude within a desired range of approximately 3000 to 4000 Hz, and while remaining at the highest amplitude in the system. The presence of the tube  110  thus improves the overall sound quality and durability of the golf club head  10 , which allows for the use of cheaper metals and cheaper manufacturing processes. The tube  110  also creates a peak that is more than 8 dB higher than all other peak frequencies of the preferred embodiment, and which is greater than 3000 Hz, as shown in FIG.  16 . As shown in  FIG. 16 , this type of peak is not present in equivalent golf club heads having adjustable weighting but lacking the tube  110  of the present invention. The preferred sound of a driver-type golf club is in the 3000-6000 Hz range, and it is preferable to have only one peak with an amplitude of 8-20 db greater than other peaks. 
     As shown in  FIGS. 2A, 2B, 13, and 14 , the center of gravity height adjustment assembly  100  preferably is located within the interior cavity  70  of the golf club head  10  in a crown  30  to sole  40  direction, running parallel to the tangent vector of the face  50 , and the center of gravity height adjustment preferably occurs in the vertical Z-axis plane. In alternative embodiments, shown in  FIGS. 17 and 18 , the center of gravity height adjustment assembly  100  can be disposed anywhere within the interior cavity  70  of the golf club head  10 , and can extend diagonally or horizontally from different locations within the golf club head  10 . 
     The design approach described herein is based on the construction used in the Callaway Golf Company RAZR Fit driver head, characterized by a composite crown adhesively bonded to a cast titanium body, which includes a face, sole, and adjustable hosel. However, this center of gravity adjustment assembly may be used with other golf club head constructions, including all titanium, all composite, and a composite body with a metal face cup. It may also be used with other type of golf club heads, including fairway woods, hybrids, and utility irons. It is also intended to work in conjunction with at least one adjustable weight port disposed anywhere on the club head, including the crown and sole, and a slidable weight. 
     The disclosure of each of U.S. Pat. Nos. 7,147,573, 7,163,468, 7,163,470, 7,166,038, 7,214,143, 7,252,600, 7,258,626, 7,258,631, 7,273,419, 8,337,328, 8,317,636, and 8,262,506 is hereby incorporated by reference herein in its entirety. 
     From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.