Patent Publication Number: US-8529368-B2

Title: Golf club head

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 13/555,406, filed on Jul. 23, 2012, which claims priority to U.S. Provisional Patent Application No. 61/578,789, filed on Dec. 21, 2011, the disclosure of each of which is 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 having a flexible face designed to improve golf ball launch conditions. The flexibility of the face is enhanced through the inclusion of an elongated recess in the sole of the golf club head. 
     2. Description of the Related Art 
     Traditionally, wood-type and hybrid-type golf club heads are manufactured by welding a face plate or a formed or cast face cup to a body made of one or more pieces. The face causes a golf ball striking the face to launch away from the golf club head. Golf clubs that are currently available on the market, however, do not provide optimized flexibility for impact with golf balls without impacting other factors involved in hitting a golf ball. 
     For example, several golf clubs currently on the market include sole features proximate the face that are intended to improve golf ball launch conditions. These sole features are slots or grooves having parallel side walls, as shown in  FIG. 1 , or side walls that slope away from each other as they approach the ground plane, as shown in  FIG. 2 . In both of these examples, the width of the bottom, innermost part of the groove (x 1 ) is less than or equal to the width of the top, outermost part of the groove (x 2 ). These groove structures typically are selected for ease of manufacture, but they do not provide optimized ball launch conditions. Furthermore, these groove structures can interfere with a golfer&#39;s swing because the large discontinuity in their openings causes the back edge of the groove to catch the turf during downswing and at impact. 
     Another fundamental problem with these groove structures is the fact that the groove opening (x 2 ) drives the design of the groove. If a larger inner surface (x 1 ) is required to improve launch performance, then the groove opening (x 2 ) must also increase, thus impacting the visual appearance of the sole and increasing the likelihood of unwanted turf interaction during play. Therefore, there is a need for a golf club construction that provides improved golf ball launch conditions without also creating unwanted turf interactions. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to golf club body features that optimize launch conditions of a golf ball impacted on the face of a golf club head while simultaneously reducing interference created by other factors, including turf interaction. 
     One aspect of the present invention is a golf club head comprising a face component, a body, and a sole plate, wherein the sole plate is affixed to the face component with a lap joint, and wherein the sole plate is bonded to the body. The lap joint may comprise a compliant adhesive or a compliant sealant, and the component, body, and sole plate may each be composed of a metal material, which can be 17-4 steel. The golf club head may be a fairway wood head or a hybrid head. The face component may be integrally formed with the body, or it may be welded to the body after formation. The face component may further comprise variable face thickness for hitting optimization. In one alternative embodiment, the face component may be a metal face cup, the body and sole plate may both be made of metal, and the sole plate may be affixed to the face cup with a compliant adhesive and attached to the body via welding. 
     Another aspect of the present invention is a golf club head comprising a face component composed of 17-4 steel, a body comprising a crown portion, a side portion, and a sole portion, the body composed of 17-4 steel, and a sole plate composed of 17-4 steel, the sole plate comprising a front ledge and a back ledge, wherein the front ledge is affixed to the face component with a bonded lap joint, wherein the back ledge is welded to the sole portion of the body, and wherein the front ledge overlaps the face component. The front ledge may be disposed on an interior surface of the face component. The golf club head may have a volume of 150 to 300 cubic centimeters, and it may be selected from the group consisting of a driver head, a fairway wood head, and a hybrid head. 
     Yet another aspect of the present invention is a golf club head comprising a face component and a sole comprising an elongated recess disposed proximate the face component, wherein the recess comprises an innermost surface and an opening, wherein the opening comprises a first width, wherein the innermost surface of the recess comprises a second width, and wherein the first width is less than the second width. In some embodiments, the recess may extend from a heel side of the golf club head to a toe side of the golf club head. In some embodiments, the recess may comprise two overlapping prongs, and the opening may comprise an axis that forms anon-ninety degree angle with a ground plane. In some alternative embodiments, the opening may comprise an axis that is approximately perpendicular to a ground plane. In other embodiments, the opening may comprise an axis that forms a non-ninety degree angle with a ground plane. 
     In some embodiments of this aspect of the present invention, the recess may be tube shaped. In other embodiments, the recess may comprises two side walls, wherein the innermost surface may be planar and may be parallel with a ground plane, and at least one of the side walls may have an axis that forms a non-ninety degree angle with the ground plane some further embodiments, both side walls may have axes that form non-ninety degree angles with the ground plane. In some embodiments, the golf club head may further comprise a cover, which may be affixed to the sole so that it partially covers the opening. In these embodiments, the sole may comprise a shallow recess sized to receive the cover such that the cover is flush with the sole when the cover is disposed within the shallow recess. The cover may be removably affixed to the sole, and in some embodiments the cover may be composed of a high density material. 
     In some embodiments of this aspect of the present invention, the golf club head may be selected from the group consisting of a driver head, a fairway wood head, and a hybrid head. In other embodiments, the golf club head may have a volume of no less than 50 cubic centimeters and no more than 250 cubic centimeters. In some embodiments, the face and the sole of the golf club head may be integrally cast from a metal alloy. 
     Another aspect of the present invention is a wood-type golf club head comprising a metal body comprising a crown, a face, a sole, a heel side, and a toe side, and a tube shaped recess disposed in the sole proximate the face, wherein the tube shaped recess extends from the heel side to the toe side, wherein the tube shaped recess comprises a curved inner surface and an opening, wherein the width of the opening is less than or equal to half of a width of the curved inner surface, and wherein the opening comprises an axis that is perpendicular to a ground plane. In some embodiments of this aspect of the present invention, the golf club head may further comprise a junction between the face and the sole, and the tube shaped recess may be disposed no more than 0.01 inch from the junction. In some further embodiments, the tube shaped recess may have a volume of no less than 0.150 cubic inch and no more than 0.400 cubic inch. 
     Yet another aspect of the present invention is a golf club head comprising a metal face component and a metal sole comprising a heel side, a toe side, and a tube shaped recess extending from the heel side to the toe side, wherein the recess comprises two overlapping prongs, an internal diameter, and an opening, wherein the recess is disposed no more than 0.500 inch from an inner surface of the face component, wherein the opening comprises a width and an axis that forms a non-ninety degree angle with a ground plane, wherein the with of the opening is less than the internal diameter of the recess, and wherein the golf club head has a volume of no less than 50 cubic centimeters and no more than 300 cubic centimeters. In some further embodiments of this aspect of the present invention, the recess may comprise a wall with a thickness of no less than 0.020 inch and no more than 0.075 inch. 
     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 cross sectional view of a prior art golf club having a first sole groove configuration 
         FIG. 2  is a cross sectional view of a prior art golf club having a second sole groove configuration. 
         FIG. 3  is a top, perspective view of a first embodiment of the present invention. 
         FIG. 4  is a cross-sectional view of the embodiment shown in  FIG. 3  along lines  4 - 4 . 
         FIG. 5  is a close-up view of the region circled in  FIG. 4 . 
         FIG. 6  is a sole, plan view of the embodiment shown in  FIG. 3 . 
         FIG. 7  is a sole, perspective view of a second embodiment of the present invention. 
         FIG. 8  is a cross-sectional view of the embodiment shown in  FIG. 7  along lines  8 - 8 . 
         FIG. 9  is a sole, perspective view of a third embodiment of the present invention. 
         FIG. 10  is a cross-sectional view of the embodiment shown in  FIG. 9  along lines  10 - 10 . 
         FIG. 11  is a sole, perspective view of a fourth embodiment of the present invention. 
         FIG. 12  is a cross-sectional view of the embodiment shown in  FIG. 11  along lines  12 - 12 . 
         FIG. 13  is a sole, perspective view of a fifth embodiment of the present invention. 
         FIG. 14  is a cross-sectional view of the embodiment shown in  FIG. 13  along lines  14 - 14 . 
         FIG. 15  is a sole, perspective view of a sixth embodiment of the present invention. 
         FIG. 16  is an exploded, perspective view of the embodiment shown in  FIG. 15 . 
         FIG. 17  is a cross-sectional view of the embodiment shown in  FIG. 15  along lines  17 - 17 . 
         FIG. 18  is a sole, perspective view of a seventh embodiment of the present invention. 
         FIG. 19  is an exploded, perspective view of the embodiment shown in  FIG. 18 . 
         FIG. 20  is a cross-sectional view of a seventh embodiment of the present invention shown in  FIG. 18  along lines  20 - 20 . 
         FIG. 21A  is a graph comparing normalized launch angles of a standard fairway wood and a fairway wood comprising the fifth embodiment of the present invention. 
         FIG. 21B  is a graph comparing normalized ball speeds of a standard fairway wood and a fairway wood comprising the fifth embodiment of the present invention. 
         FIG. 21C  is a graph comparing normalized backspin of a standard fairway wood and a fairway wood comprising the fifth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is generally directed to a golf club head with an improved structure designed to reduce energy loss during impact of a golf club head with a golf ball, optimize and balance ball speed robustness, launch angle, and backspin, and reduce turf interaction by minimizing sole discontinuity. 
     Sole Lap Joint 
     A first embodiment of the present invention, shown in  FIGS. 3-6 , comprises a golf club head  10  with a face component  20 , a body  30 , and a sole plate  40  affixed to the face component with a bonded lap joint  50 , which permits the golf club face  20  to flex in an optimized way upon impact with a golf ball. The back part of the sole plate  40  is preferably welded to the body  30  to form a seam  42 , and the bonded lap joint  50  preferably comprises a compliant adhesive or sealant  60 . The area of the sole plate  40  proximate the lap joint  50  preferably includes an overlap portion  45 , which overlaps at least part of the face component  20 , preferably on an inside surface of the face component  20 . The sole plate  40  also preferably includes a reveal dimension  48  representing a visible recessed area proximate the overlap portion  45 . The reveal dimension  48  preferably is small so as to avoid unwanted turf interaction during play. 
     The face component  20  of the golf club head  10  of the first embodiment preferably is integrally formed with the body  30  for the sake of efficiency during manufacturing, such that a hole is left in the sole of the head  10 . This hole is then covered with the sole plate  40 , which can be cast, formed, rolled or cut from a metal material. This configuration lowers the overall center of gravity (CG) of the club head  10 , particularly if the sole plate  40  is formed of a high density material, prevents the CG from moving forward as far as it would if there were a slot or gap between the face  20  and the sole plate  40 , and permits the use of cast 17-4 steel in construction of the head  10 , which reduces the manufacturing cost of the head  10  when compared to the use of expensive metals like titanium alloy. The head  10  shown in the first embodiment also does not have an exposed cavity in its sole, which prevents the club head  10  from collecting debris or dirt during use. 
     Modified Groove 
     Other embodiments of the present invention are directed to grooves that optimize launch conditions without creating unwanted turf interactions. This is accomplished by de-coupling the groove&#39;s shape from its exit geometry size and shape, white at the same time allowing for ease of manufacture, visually appealing aesthetics, and increased performance metrics. As shown in each of the following embodiments, unwanted sole discontinuity, and the resulting turf interaction, is minimized by narrowing the surface opening of the groove. These grooves are also designed to increase the resulting ball speed of a golf ball struck by a head incorporating the grooves without negatively impacting other factors that affect striking distance, including launch angle and backspin. 
     For example, the sole grooves  110 ,  120  included in the second and third embodiments of the present invention, illustrated  FIGS. 7-8  and  9 - 10  respectively, have trapezoidal configurations, each with an opening  116 ,  126  having an axis  115 ,  125  that is substantially perpendicular to the ground plane  100 , and a width (x 2 ) that is smaller than the width (x 1 ) of the inner most surface  118 ,  128  of the groove  110 ,  120 . The second embodiment has one negative draft wall  112  and another wall  114  that is approximately perpendicular to the ground plane  100 , white the third embodiment has two negative draft walls  122 ,  124 , creating a smaller opening than the one created by the structure of the second embodiment. These sole grooves  110 ,  120  can be created using casting undercutting methods that are well known in the art. 
     Novel manufacturing techniques can be utilized to further optimize the surface opening of a groove, thus improving the interaction between the golf club and the turf. As shown in  FIGS. 11-12 , a fourth embodiment of the present invention includes a tube-shaped sole groove  130  with an opening  136  that has an even smaller width (x 2 ) than those disclosed in  FIGS. 7-10 . This opening  136  preferably is integrally manufactured with the golf club head  10 , but in an alternative embodiment the opening  136  can be cut into the tube-shaped groove  130  after the head  10  has been fabricated. 
     A fifth, preferred embodiment of the present invention, shown in  FIGS. 13-14 , includes a tube-shaped groove  140  with overlapping prongs  141 ,  142  that form an opening  146  having an axis  145  that is angled with respect to the ground plane  100  and a width (x 3 ) that is the same as or smaller than the widths (x 2 ) of the other sole grooves disclosed herein. The width (x 3 ) of the opening  146  can be adjusted by moving the overlapping prongs  141 ,  142  of the groove  140  closer together or further apart. This groove  140  illustrates how features of the opening  146  can be adjusted without changing the overall shape of the groove  140 , which in the fifth embodiment is practically identical to the tube-shaped groove  130  of the fourth embodiment. The tube shaped groove  140  shown in  FIGS. 13-14  preferably is integrally formed via casting, but may be constructed from several pieces, as shown in  FIGS. 16A and 16B  and described herein. As shown in  FIGS. 21A ,  21 B, and  21 C, the tube-shaped groove  140  of the preferred embodiment, when incorporated into a 3-wood head, increases the ball speed of a golf ball struck at the center and low center of the golf club face, and decreases the backspin, without significantly affecting other important factors, including launch angle, that contribute to a golf ball&#39;s flight distance. 
     Sixth and seventh embodiments of the present invention are shown in  FIGS. 15-20 . These golf club heads include grooves  150 ,  160  with structures that are similar to the structure of the groove  140  of the preferred embodiment, in that they are tube-shaped and include openings  156 ,  166  with axes  155 ,  165  that are angled with respect to the ground plane  100 , but these grooves  150 ,  160  are constructed from more than one piece of the golf club head  10  and thus can be formed using more traditional manufacturing processes. Specifically, the curved portion  152 ,  162  of these grooves  150 ,  160  can be formed by casting, forming, or machining the club head  10 . The grooves  150 ,  160  are finished by affixing a sole plate or cover  200  to an exterior surface of the sole  15  to at least partially close the opening  156 ,  166  and alter its geometry. The sole  15  preferably has a recessed region  17  sized to receive the cover  200  so that it is flush with the surface of the sole and does not create any surface discontinuities. 
     The size, thickness, and material composition of the cover  200  preferably is selected by the manufacturer to affect the location of the club head&#39;s  10  center of gravity, the thickness of the sole  15 , and the overall weight of the golf club head  10 . The cover  200  may be small, as shown in  FIGS. 15-17 , to minimize added weight, or it may be large, as shown in  FIGS. 18-20 , to affect the characteristics of the golf club head  10  more significantly. The cover  200  may be affixed to the sole  15  by welding, bonding, brazing, mechanical fasteners, or a combination of these methods, which may be determined by the material used to create the cover  200 . In some embodiments, the cover  200  is removably affixed to the sole  15  of the golf club head  10  to permit golfers to customize and adjust features of their golf club, including overall head weight and center of gravity location. 
     The grooves  150 ,  160  shown in  FIGS. 15-20  represent a hybrid approach to face performance optimization because they have the novel, tube-shaped structure shown in  FIGS. 11-14 , and also include a feature of the prior art groove shown in  FIG. 1 . Specifically, the width (Y 1 ) of these grooves&#39;  150 ,  160  inward-most portion  158 ,  168  is approximately equivalent to the width (Y 2 ) of the grooves&#39;  150 ,  160  openings  156 ,  166  before they are altered by the cover  200 . In alternative embodiments, the openings  156 ,  166  may have axes that are perpendicular to the ground plane  100  to further resemble the prior art grooves. 
     The embodiments shown in  FIGS. 7-20  have grooves with configurations that completely decouple the groove opening size and shape from the actual groove size and shape, thus allowing both features to be optimized independently. For example, internal groove dimensions can be optimized for launch condition performance, while the groove opening can be optimized for turf interaction and increased aesthetic appeal. Specifically, the grooves  130 ,  140 ,  150 ,  160  of the fourth, fifth, sixth, and seventh embodiments of the invention have the following dimensions designed to optimize performance. The widths (x 2 , x 3 ) of the openings  136 ,  146 ,  156 ,  166  are preferably between 0.010 and 1.00 inch, and more preferably between 0.030 and 0.075 inch, and most preferably approximately 0.040 inch. The openings  136 ,  146 ,  156 ,  166  preferably are located between 0.100 and 1 inch from the front surface  21  of the face  20 , more preferably between 0.200 and 0.500 inch from the front surface  2 , and most preferably approximately 0.330 inch from the front surface  21  of the face. The wall  132 ,  142 ,  53 ,  163  thicknesses of the grooves  130 ,  140 ,  150 ,  160  are preferably between 0.010 and 0.200 inch, more preferably between 0.020 and 0.075 inch, and most preferably approximately 0.030 inch. 
     The grooves  130 ,  140 ,  150 ,  160  preferably have diameters (x 1 ,y 1 ) of between 0.030 and 1 inch, more preferably between 0.100 and 0.500 inch, and most preferably of 0.310 inch, and a volume of between 0.100 and 1 cubic inch, more preferably between 0.200 and 0.500 cubic inch, and most preferably 0.145 cubic inch. The grooves  130 ,  140 ,  150 ,  160  preferably are located proximate an inner surface  22  of the golf club face  20 , preferably between 0.005 and 1 inch, more preferably between 0.010 and 0.050 inch, and most preferably approximately 0.030 inch, and are preferably located between 0.010 and 1 inch from a front surface  21  of the face  20 , more preferably between 0.100 and 0.500 inch from the from surface  21 , and most preferably approximately 0.150 inch from the front surface  21 . The grooves  130 ,  140 ,  150 ,  160  also preferably have a depth (d) from the innermost point of the groove  130 ,  140 ,  150 ,  160  to the ground plane  100  of between 0.010 inch and 1 inch, more preferably between 0.100 and 0.500 inch, and most preferably 0.410 inch. A golf club head incorporating one or more grooves  130 ,  140 ,  150 ,  160  of the present invention preferably has a sole  15  thickness of 0.030 to 0.50 inch, more preferably 0.040 to 0.100 inch, and most preferably 0.060 inch. 
     The sole grooves described herein can be used with any type of golf club head, but are preferably used with wood and hybrid-type clubs, and most preferably with fairway woods. Each of the grooves described herein may extend partially or completely across the golf club sole, and preferably extend in a toe-heel direction proximate the face. In alternative embodiments, the grooves described herein may be disposed on regions of the golf club head  10  other than the sole. For example, the grooves may extend along the heel and toe sides of the golf club head, or across the crown, as disclosed in U.S. Patent Application Publication Number 2011/0218053, the disclosure of which is hereby incorporated by reference in its entirety herein. 
     The golf club heads disclosed herein may have any volume, shape, or proportions and can be formed from one or more materials, including those material compositions disclosed in U.S. Pat. Nos. 6,244,976, 6,332,847, 6,386,990, 6,406,378, 6,440,008, 6,471,604, 6,491,592, 6,527,650, 6,565,452, 6,575,845, 6,478,692, 6,582,323, 6,508,978, 6,592,466, 6,602,149, 6,607,452, 6,612,398, 6,663,504, 6,669,578, 6,739,982, 6,758,763, 6,860,824, 6,994,637, 7,025,692, 7,070,517, 7,112,148, 7,118,493, 7,121,957, 7,125,344, 7,128,661, 7,163,470, 7,226,366, 7,252,600, 7,258,631, 7,314,418, 7,320,646, 7,387,577, 7,396,296, 7,402,112, 7,407,448, 7,413,520, 7,431,667, 7,438,647, 7,455,598, 7,476,161, 7,491,134, 7,497,787, 7,549,935, 7,578,751, 7,717,807, 7,749,096, and 7,749,097, the disclosure of each of which is hereby incorporated in its entirety herein. 
     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.