Abstract:
A golf club head according to one or more aspects of the present invention comprises a sole portion, a crown portion, and a stiffening element associated with at least one of the crown portion and the sole portion. The stiffening element has a survey length and at least one welded portion, comprising less than about 70% of the survey length. The stiffening element further comprises a plurality of welded portions. The welded portions adjacent each other are separated by a distance between about 10 mm and about 100 mm. A method of producing a golf club head comprises identifying a plurality of high-deflection regions having a plurality of ranges and providing a stiffening element, at least in part coupled with the plurality of high-deflection regions. The stiffening element comprises a plurality of heights and/or widths corresponding to the plurality of deflection ranges. At least one of the plurality of heights and/or widths is different from at least another of the plurality of heights and/or widths.

Description:
COPYRIGHT AUTHORIZATION 
       [0001]    The disclosure below may be subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the documents containing this disclosure, as they appear in the Patent and Trademark Office records, but otherwise reserves all applicable copyrights. 
       BACKGROUND 
       [0002]    Wood-type golf club heads generally weigh between about 150 g and about 250 g. A portion of this mass sustains the structural integrity of the club head. The remaining mass, referred to as “discretionary” mass, may be strategically distributed to improve the mass properties and/or the inertial characteristics of the head. 
         [0003]    It is well known in the art that the dynamic-excitation response of a golf club head may have a profound effect on the player&#39;s confidence and performance. Many golfers associate a pleasing sound at ball impact with superior performance and a poor sound with inferior performance. 
         [0004]    Wood-type club heads have increased in size in recent years to enlarge the sweet spot of the striking surface. As the size of the club head has increased, most manufacturers have thinned the club-head walls to maintain the head weight within a useable range. However, such a construction often adversely affects the dynamic-excitation response of the club head at ball impact because the thinned walls of the head possess a plurality of high-deflection regions that promote unfavorable vibrational frequencies. To improve the dynamic-excitation response of the club head, the regions of high deflection may be reinforced with, e.g., rib-like structures or stiffening elements. Typically, each region of high deflection is provided with a discrete stiffening structure, thus significantly reducing the available discretionary mass of the club head. 
       SUMMARY 
       [0005]    The present invention, in one or more aspects thereof, may comprise a golf club head having greater forgiveness on mishit shots, reduced hook/slice tendencies, and an improved dynamic-excitation response. 
         [0006]    In one example, a golf club head in accordance with one or more of aspects of the present invention may include a crown portion, a sole portion, and a stiffening element associated with at least one of the crown portion and the sole portion. The stiffening element may comprise a survey length and at least one welded portion comprising less than about 70% of the survey length. 
         [0007]    In another example, a golf club head in accordance with one or more aspects of the present invention may include a crown portion, a sole portion, and a stiffening element associated with at least one of the crown portion and the sole portion. The stiffening element may comprise a plurality of welded portions, wherein the adjacently located welded portions adjacent may be separated by a distance between about 10 mm and about 100 mm. 
         [0008]    In another example, a method of producing a golf club head in accordance with one or more aspects of the present invention may comprise identifying a plurality of high-deflection regions having a plurality of deflection ranges and providing a stiffening element, at least in part coupled with the plurality of high-deflection regions. The stiffening element comprises a plurality of heights corresponding to the plurality of deflection ranges. At least one of the plurality of heights is different from at least another of the plurality of heights. 
         [0009]    In another example, a method of producing a golf club head in accordance with one or more aspects of the present invention may comprise identifying a plurality of high-deflection regions having a plurality of deflection regions and providing a stiffening element, at least in part coupled with the plurality of high-deflection regions. The stiffening elements comprise a plurality of widths corresponding to the plurality of deflection ranges. At least one of the plurality of widths is different from at least another of the plurality of widths. 
         [0010]    These and other features and advantages of the golf club head according to the invention in its various aspects as provided by one or more of the examples described in detail below will become apparent after consideration of the ensuing description, the accompanying drawings, and the appended claims. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Exemplary implementations of the present invention will now be described with reference to the accompanying drawings, wherein: 
           [0012]      FIG. 1  is a top plan view of an exemplary golf club head according to one or more aspects of the present invention. 
           [0013]      FIG. 1A  is a front elevational view of the golf club head of  FIG. 1 . 
           [0014]      FIG. 1B  is a front elevational view of the golf club head of  FIG. 1  with a template applied thereto. 
           [0015]      FIG. 1C  is a front elevational view of the golf club head of  FIG. 1 . 
           [0016]      FIG. 1D  is a top plan view of the golf club head of  FIG. 1 . 
           [0017]      FIG. 1E  is a front elevational view of the golf club head of  FIG. 1 . 
           [0018]      FIG. 1F  is a top plan view of the golf club head of  FIG. 1 . 
           [0019]      FIG. 2  is a top plan view of an exemplary golf club head according to one or more aspects of the present invention. 
           [0020]      FIG. 2A  is a top plan view of an exemplary golf club head according to one or more aspects of the present invention. 
           [0021]      FIG. 2B  is a top plan view of an exemplary golf club head according to one or more aspects of the present invention. 
           [0022]      FIG. 2C  is a top plan view of an exemplary golf club head according to one or more aspects of the present invention. 
           [0023]      FIG. 3A  is a front cross-sectional view of an exemplary golf club head according to one or more aspects of the present invention. 
           [0024]      FIG. 3B  is a front cross-sectional view of an exemplary golf club head according to one or more aspects of the present invention. 
           [0025]      FIG. 3C  is a front cross-sectional view of an exemplary golf club head according to one or more aspects of the present invention. 
           [0026]      FIG. 4  is a perspective view of an exemplary golf club head according to one or more aspects of the present invention showing the club head with the crown removed. 
           [0027]      FIG. 4A  is a top plan view of an exemplary golf club head according to one or more aspects of the present invention showing the club head with the crown removed. 
           [0028]      FIG. 4B  is a top plan view of an exemplary golf club head according to one or more aspects of the present invention showing the club head with the crown removed. 
           [0029]      FIG. 4C  is a top plan view of an exemplary golf club head according to one or more aspects of the present invention showing the club head with the crown removed. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    The following examples of the golf club head according to one or more aspects of the present invention will be described using one or more definitions, provided below. 
         [0031]    Referring to  FIGS. 1 and 1A , a club head  100  may comprise a toe  102 , a heel  104 , a hosel  106 , having a central axis (centerline)  108 , a sole portion  110 , a crown portion  112 , and a face portion  107 , including a striking surface  114 . The striking surface  114  may have a top edge  116 , a leading edge  118 , and a face center  120 . 
         [0032]    Referring again to  FIGS. 1 and 1A , “reference position,” as used herein, denotes a position of the club head  100  where the hosel centerline  108  is in an imaginary vertical plane  122  and is oriented at a lie angle α of substantially 60° with respect to a ground plane  124 . The plane  122  is oriented substantially parallel to the striking surface  114 . Unless otherwise indicated, all parameters below are specified with the club head in the reference position. 
         [0033]    Referring to  FIGS. 1A and 1B , “face center”, e.g., a face center  120 , as used herein, may be located using a template  126 , having a coordinate system with a heel-toe axis  126   a  that is orthogonal to a sole-crown axis  126   b . An aperture  128  may be located at the origin of the coordinate system and each axis may be divided into evenly spaced increments. The template  126  may be made of a flexible material, e.g., a transparent polymer. The template is used as follows:
       1) The template  126  is placed on the striking surface  114  with the heel-toe axis  126   a  substantially parallel to the leading edge  118 . The template is then moved back and forth in the heel-toe direction along the striking surface  114  until the heel and toe measurements at the opposite edges of the striking surface  114  are equal.   2) The template  126  is moved back and forth in the sole-crown direction along the striking surface  114  until the sole and crown measurements at the opposite edges of the striking surface  114  are equal.   3) The template  126  is moved with respect to the striking surface  114  as described in steps 1 and 2, above, until the heel and the toe as well as the sole and the crown measurements along the corresponding axes are equal. A point is then marked on the striking surface via the aperture  128  to indicate the face center  120 .       
 
         [0037]    Referring to  FIG. 1C , “center apex”, e.g., a center apex  130 , as used herein, refers to a point of intersection between an imaginary longitudinal vertical plane  132  and the top edge  116  of the striking surface  114 , with the club head  100  in the reference position. The plane  132  is oriented substantially perpendicular to the striking surface  114  and passes through the face center  120 . 
         [0038]    Referring to  FIG. 1D , “overall length”, e.g., an overall length  134 , as used herein, denotes the shortest horizontal distance between an imaginary front vertical plane  136 , substantially parallel to the top edge  116  and passing through the center apex  130 , and an imaginary rear vertical plane  138  that is parallel to the front vertical plane  136  and passes through the furthest rearwardly projecting point  140  of the club head  100 , opposite the striking surface  114 . 
         [0039]    Referring to  FIG. 1E , “overall width”, e.g., an overall width  140 , as used herein, denotes the shortest horizontal distance between an imaginary toe-side vertical plane  142 , substantially perpendicular to the striking surface  114  and passing through a furthest laterally projecting toe point  144 , and an imaginary heel-side vertical plane  146  that is substantially perpendicular to the striking surface  114  and passes through a furthest laterally projecting heel point  148 , located at a vertical height of 1.905 cm (0.75 in) relative the ground plane  124 , with the club head  100  in the reference position. 
         [0040]    Referring to  FIG. 1F , “heel region”, e.g., a heel region  150 , as used herein, denotes the portion of the club head between the imaginary heel-side vertical plane  146 , substantially perpendicular to striking surface  114  and passing through the furthest laterally projecting heel point  148 , located at a vertical height of 1.905 cm (0.75 in) relative the ground plane  124 , and an imaginary offset heel-side vertical plane  152 . The plane  152  is parallel to the plane  146  and is spaced a distance X therefrom in the direction of toe  102 . Preferably, the distance X may be less than 20% of the overall length of the club head, more preferably less than 15% of the overall length of the club head, and most preferably less than 10% of the overall length of the club head. 
         [0041]    Referring again to  FIG. 1F , “toe region”, e.g., a toe region  154 , as used herein, denotes the portion of the club head between the imaginary toe-side vertical plane  142 , substantially perpendicular to striking surface  114  and passing through the furthest laterally projecting toe point  144 , and an imaginary offset toe-side vertical plane  156 . The plane  156  is parallel to the imaginary toe-side vertical plane  142  and is spaced a distance Y therefrom in the direction of the heel  104 . Preferably, the distance Y may be less than 20% of the overall length of the club head, more preferably less than 15% of the overall length of the club head, and most preferably less than 10% of the overall length of the club head. 
         [0042]    Referring to  FIG. 2 , “survey length”, e.g., a survey length  240 , as used herein, denotes the maximum horizontal length of a stiffening element  260  in a top plan view with the golf club head  200  in the reference position. 
         [0043]    As illustrated in  FIG. 2 , the club head  200 , oriented in the reference position, is divided into four quadrants by an imaginary longitudinal vertical plane  232 , substantially perpendicular to a striking surface  214  and passing through a face center  220 , and an imaginary transverse vertical plane  258 , orthogonal to the imaginary longitudinal vertical plane  232  and bisecting the club head  200  at one-half the overall length. A first quadrant, Quadrant  1 , is proximate the striking surface  214  and a heel  204  of the club head. A second quadrant, Quadrant  2 , is proximate the striking surface  214  and a toe  202  of the club head. A third quadrant, Quadrant  3 , is proximate the toe and is located rearward of Quadrant  2 . A fourth quadrant, Quadrant  4 , is proximate the heel and is located rearward of Quadrant  1 . 
         [0044]    Referring again to  FIG. 2 , the club head  200  may have an interior cavity characterized by a crown portion  212 , a sole portion (not shown), the toe  202 , the heel  204 , and a face portion  207 . The linear stiffening element  260  may be disposed within the interior cavity and may extend from the heel region to the toe region, as defined with respect to  FIG. 1F . 
         [0045]    To orient the stiffening element  260  within the interior cavity of the club head, at least two regions of high deflection may be identified, e.g., using computational analysis and/or empirical techniques. Once the high-deflection regions have been identified, the stiffening element  260  is disposed in at least three of the four quadrants, described above, at an angle θ to the imaginary longitudinal vertical plane  232 , such that the stiffening element  260  passes through at least two of the identified regions of high deflection to improve the dynamic excitation response of the club head. For example, the linear stiffening element  260  may be oriented at an angle between 50° and 85° relative to the plane  232 , preferably between 60° and 85° relative to the plane  232 , and more preferably between 70° and 85° relative to the plane  232 , depending on the location of the high-deflection regions of the club head. By using a single stiffening element to reinforce more than one high-deflection region, an increase in discretionary mass may be achieved. The discretionary mass may be distributed in the club head to improve mass properties and/or inertial characteristics. 
         [0046]    The stiffening element, according to one or more aspects of the present invention, may be disposed within the interior cavity in any orientation. For example, as shown in  FIG. 2 , the stiffening element  260  may be disposed in the first, second, and third quadrants at an angle θ to the imaginary longitudinal vertical plane  232 . In other examples, the stiffening element, e.g., stiffening element  260   a  ( FIG. 2A ), may be disposed in the first, third, and fourth quadrants. Preferably, the stiffening element, e.g., stiffening element  260   b  ( FIG. 2B ), may be disposed in the second, third, and fourth quadrants. More preferably, stiffening element, e.g., stiffening element  260   c  ( FIG. 2C ), may be disposed in the first, second, and fourth quadrants. 
         [0047]    Referring to  FIGS. 2-2C , the use of an advantageously oriented stiffening element, according to one or more aspects of the invention, e.g., stiffening elements  260 - 260 C, produces a club head having a favorable dominant resonant frequency of vibration. The dominant resonant frequency of vibration is the frequency that produces the greatest sound energy. To measure the sound energy of a given resonant frequency, a time-amplitude plot, with the amplitude along the y-axis and the time along the x-axis, may be generated. The resonant frequency having the greatest area underneath the curve is the dominant resonant frequency of vibration. Generally, the first resonant frequency of vibration is the dominant resonant frequency. Preferably, the first resonant frequency of vibration may be between about 1800 Hz and about 7500 Hz, more preferably between about 2500 Hz and about 6000 Hz, and most preferably between about 3000 Hz and about 5000 Hz. In some instances, the dominant resonant frequency may be the second, the third, the fourth, or the fifth resonant frequency of vibration. 
         [0048]    Further tuning of the dynamic-excitation response of the club head may be achieved by modifying the width and/or height of at least a portion of the stiffening element, according to one or more aspects of the present invention, in the regions of high deflection. For example, the stiffening element may comprise one or more heights corresponding to one or more regions of high deflection. Moreover, the stiffening element may comprise one or more widths corresponding to one or more regions of high deflection. Increasing the height and/or the width of the stiffening element advantageously reduces the deflection in the corresponding region or regions of the club head. The width of the stiffening element may vary between about 0.2 mm and about 5 mm, preferably between about 0.75 mm and about 2 mm, and more preferably between about 1 mm and 1.5 mm. The height of the stiffening element may vary between about 1 mm and about 25 mm, preferably between about 3 mm and about 20 mm, more preferably between about 5 mm and about 15 mm, and most preferably between about 8 mm and about 12 mm. 
         [0049]    The survey length, e.g., the survey length  240  ( FIG. 2 ), of the stiffening element  260  may be greater than the overall width of the club head. For example, the ratio of the overall width to the survey length may be less than 0.97, preferably less than 0.95, more preferably less than 0.90, and most preferably between 0.85 and 0.97, depending on the angle between the stiffening element  260  and the plane  232 . A longer stiffening element may be required to reinforce multiple regions of high deflection. The overall width of the club head may be greater than about 110 mm, preferably greater than about 115 mm, and more preferably greater than about 130 mm. The survey length, e.g., the survey length  240 , may be at least about 50 mm, preferably at least about 100 mm, and more preferably at least about 125 mm. 
         [0050]    The stiffening element, in one or more aspects thereof, may be coupled to at least one of the sole portion and the crown portion, e.g., by welding, adhesive bonding, or integrally casting the stiffening element with the club head. Suitable adhesives include thermosetting adhesives in a liquid or a film medium, e.g., two-part liquid epoxy, modified acrylic liquid adhesive, foam tape, or the like. 
         [0051]    Referring to  FIG. 3A , orientation of the stiffening element relative the crown and/or the sole may be determined by the location of the high-deflection regions of the club head. For example, regions of high deflection may be located on both the sole portion  310   a  and the crown portion  312   a . As shown in  FIG. 3A , the stiffening element  360   a  may be coupled to both the sole portion  310   a  and the crown portion  312   a  to reinforce such high-deflection regions, thus improving the dynamic-excitation response of the club head. Additionally, the stiffening element may be coupled to portions of the club head other than the sole portion and the crown portion. 
         [0052]      FIG. 3B  illustrates a club head where the regions of high deflection may be located primarily in a sole portion  310   b  of club head  300   b . Hence, a single linear stiffening element  360   b  may be disposed on the sole portion. In another example, shown in  FIG. 3C , the regions of high deflection may be located primarily on a crown portion  312   c  of the club head  300   c . Thus, a single linear stiffening element  360   c  may be disposed on the crown portion. 
         [0053]    The stiffening elements described above may be formed from metallic and/or non-metallic materials. Examples of metallic materials suitable for fabricating the stiffening elements may include stainless steel, 6-4 titanium alloy, 10-2-3 Beta-C titanium alloy, 6-22-22 titanium alloy, or the like. Suitable non-metallic materials may include composite materials, e.g., CFRP, and thermoplastic materials, e.g., polyurethanes, polyesters, polyamides, and ionomers. The stiffening elements may be manufactured, e.g., via a casting, forging, powdered metal forming, or injection molding process. 
         [0054]    Referring to  FIG. 4 , one or more welds, e.g., welds  462 , may be utilized to couple the stiffening element, e.g., a stiffening element  460 , to the club head. To reduce the production costs and increase production efficiency, the weld or welds may comprise less than about 70% of the survey length of the stiffening element. In another example, the weld or welds may comprise less than about 50% of the survey length, preferably less than about 30% of the survey length, and more preferably less than about 20% of the survey length. 
         [0055]    As shown in  FIG. 4 , the stiffening element, e.g., the element  460 , according to one or more aspects of the present invention, may be coupled to the sole portion, e.g., a sole portion  410 , via a plurality of intermittent welds and/or tack welds. Preferably, each weld may be located in a region of high deflection to improve the dynamic-excitation response of the club head. Spacing between the adjacent ends of neighboring welds depends on the number and location of the high-deflection regions in the club head. Thus, each weld may be spaced between about 10 mm and about 100 mm from an adjacent weld, preferably between about 10 mm and about 50 mm from an adjacent weld, and more preferably between about 10 mm and about 25 mm from an adjacent weld. 
         [0056]    Referring to  FIG. 4A , the stiffening element, e.g., a stiffening element  460   a , may comprise a first side, e.g., a first side  464   a , and a second side, e.g., a second side  466   a . A plurality of welds  462   a  may be deposited in a paired arrangement along the first and the second sides of the stiffening element  460   a . As shown in  FIG. 4B , the welds, e.g., welds  462   b , may be located along only one side of the stiffening element. The welds, e.g., welds  462   c , may also be disposed in a staggered arrangement on both sides of the stiffening element, as shown in  FIG. 4C . 
         [0057]    The club head may be formed from a wide variety of materials, including metals, polymers, ceramics, composites, and wood. For instance, the club heads according to one or more aspects of the present invention may be made from stainless steel, titanium, or graphite fiber-reinforced epoxy, as well as persimmon or laminated maple. In one example, the club head may be formed, at least in part, of fiber-reinforced or fiberglass-reinforced plastic (FRP), otherwise known as reinforced thermoset plastic (RTP), reinforced thermoset resin (RTR), and glass-reinforced plastic (GRP). 
         [0058]    The face portion of the club headmay be formed of SP700 Beta Titanium—an alpha/beta grade alloy of 4.5-3-2-2 Titanium (Ti-4.5% Al-3% V-2% Mo-2% Fe). In another example, portions of the club head may be formed of other titanium alloys including a forging of a high strength titanium alloy such as 10-2-3 (Ti-10% V-2% Fe-3% Al) or 15-3-3-3 (Ti-15% V-3% Cr-3% Sn-3% Al), a casting of a 6-4 alloy (Ti-6% Al-4% V), or other titanium alloys such as 3-2.5 Titanium (Ti-3% Al-2.5% V) or 15-5-3 Titanium (Ti-15% Mo-5% Zr-3% Al). In other examples, other forging and casting alloys may be used including stainless steel and aluminum. 
         [0059]    In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.