Patent Publication Number: US-2007099726-A1

Title: Sole configuration for metal wood golf club

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates to golf clubs and in particular to wood or metal wood type golf club heads having an improved sole configuration.  
      The way the sole of a golf club impacts the ground surface during the execution of a golf shot often determines the ball flight and the overall results of the shot. The leading edge of a golf club head is the edge at the interface of the bottom sole and lower portion of the ball striking face. It is well known in order to prevent the leading edge from digging into the ground at impact with a golf ball, the bottom sole configuration is formed with a downwardly extending, angular surface toward the rear edge of the club head that raises the leading edge above the ground. This is known in the art as the bounce of the club head, the bounce angle being the angle of the bottom sole relative to the horizontal when the club head is in a normal address position prior to the execution of a golf swing. Therefore, golf clubs with different bounce characteristics will react differently with the ground surface as the club head impacts with the ground during a golf shot.  
      Typically, a golf club with a higher bounce angle is considered to have more bounce. Typical bounce angles vary between 6 and 12 degrees. However, the effective bounce of a club head may also vary by changing the overall length of the bounce surface that engages the ground. For example, a larger bounce angle combined with a shorter bounce surface will create the same effective bounce as a lesser bounce angle with a wider ground engaging surface, since each structure will raise the leading edge of the club head the same height above the ground support surface. Bounce is particularly useful for golf clubs that are used to hit shots out of sand bunkers to enable the club to be swung down and through the sand without digging too deeply therein.  
      Even when a golf ball lies on smoothly cut grass or turf, the bounce and sole configuration will effect the results of the golf shot. This is particularly true when more severe conditions are encountered, such as extremely hard or soft surfaces. For example, when a golf club impacts a hard surface, the club head will tend to bounce resulting in the golf ball being hit thin resulting in a lower golf shot. When a ground surface is soft, a golf club may embed in the ground resulting in the loss of club head speed causing the golf ball to fly short of the intended target. Prior art golf club heads have been made with bottom sole configurations to control the way a golf club head reacts with the ground for the purpose of better controlling a golf shot.  
     SUMMARY OF THE INVENTION  
      The present invention is a metal wood type golf club head of conventional design with an improved sole configuration to increase the effective bounce of the club head. The bottom sole surface is formed in separate sections. A first forward sole section is located directly behind the leading edge of the club head and extends partway to the rear of the club head. The forward sole section is formed of a generally flat or planar land area at an angle downward from the horizontal when the club head is in a normal address position just prior to the execution of a golf shot. This angle is the bounce angle and raises the leading edge above the ground surface. The forward section provides a frictional surface that impacts the ground as a golf ball is hit with the club head. The bounce angle of the forward section prevents the club head from digging into the turf or ground and actually causes the club head to bounce. The bottom sole includes at least a second section behind the forward sole bounce section. The second section extends upwardly and inwardly and recesses into the club head body so it is raised above the ground surface with the club head at the address position. There is less friction on the second section surface since it is raised relative to the ground as a golf ball is hit by the club head. The raised second section preferably has an aerodynamic or airfoil shape that traps air between the bottom sole and ground creating lift and increasing club head speed.  
      Another feature of the sole structure is increased mass low on the club head because of the increased surface area and thickness of the metal wood shell in the lower areas. This produces a higher trajectory ball flight for a given loft angle of the clubface. This, in turn, allows for a lower loft angle for a given ball flight resulting in increased distance for a given swing force. Because of this combination of bounce, loft angle and lower weight, lower lofted clubs, such as drivers, may be used in the fairway resulting in longer golf shots for a given swing force.  
      In various embodiments, the club head may be provided with a rear edge of the bottom sole that rests the club head on the ground for increases stability. The club head may have a flat mid section to stabilize the club at address. Similarly the bottom sole of the club head may have a forward or bounce section of various sizes and bounce angles.  
      The present invention is particularly adaptable for metal wood type golf clubs and in particular to fairway woods. The invention is also adapted for driver type golf clubs and allows drivers to hit a golf ball off closely cut fairway grasses.  
      Among the objects of the present invention is the provision of a metal wood golf club head with an improved bottom sole configuration having a reduced frictional surface.  
      Another object of the present invention is the provision of a metal wood having an improved sole configuration to facilitate hitting a golf ball from a fairway grass surface.  
      Another object of the present invention is the provision of a metal wood golf club head with an improved bottom sole configuration with a bounce angle at the leading edge.  
      Still another object of the present invention is the provision of a metal wood golf club head with an improved bottom sole configuration having an aerodynamic lower surface.  
      Yet another object of the present invention is the provision of a metal wood golf club head with an improved bottom sole configuration allowing a driver lofted club to be used from the fairway grass.  
      These and other objects will become apparent with reference to the following specification and accompanying drawings.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a toe side elevational view of a metal wood type golf club head in accordance with the present invention.  
       FIG. 2  is a bottom view thereof.  
       FIG. 3  is a front elevational view thereof  FIG. 4  is a top plan view thereof.  
       FIG. 5  is a sectional view taken along line  5 - 5  of  FIG. 4 .  
       FIG. 6  is a view of three sizes of metal wood golf clubs of the present invention.  
       FIG. 7  is a toe side elevational view of another embodiment of a metal wood golf club head in accordance with the present invention.  
       FIG. 8  is a bottom view of the club head of  FIG. 7 .  
       FIG. 9  is a toe side elevational view of another embodiment of a metal wood golf club head in accordance with the present invention.  
       FIG. 10  is a bottom view of the club head of  FIG. 9 .  
       FIG. 11  is a toe side elevational view of another embodiment of a metal wood golf club head in accordance with the present invention.  
       FIG. 12  is a bottom view of the club head of  FIG. 11 .  
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Detailed embodiments of the present invention are disclosed herein. It should be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore the details disclosed are not to be interpreted as limiting, but merely form a basis for the claims and as a basis for teaching one of ordinary skill in the art how to make and/or use the invention.  
      Referring to the drawings, FIGS.  1  to  5  disclose a metal wood golf club head 100  of the present invention formed with a body portion  102  made of a hard metal material, forming a metal shell  104 . The club head  100  includes a ball striking face  106 , heel  108 , toe  110 , rear face  112 , top crown  114 , and bottom sole  116 . The club head  100  is preferably formed with a hosel  118  connected to a conventional shaft  120  of any suitable length and handle or grip (not shown) on the upper end thereof.  
      The bottom sole  116  is formed in separate sections. A first forward sole section  122  is located directly behind the leading edge  124  of the club head  100  and extends partway to the rear face  112  of the club head  100 . The forward sole section  122  is formed of a flat or planar land area at an angle downward from the horizontal when the club head  100  is in a normal address position just prior to the execution of a golf shot. This angle is the bounce angle and raises the leading edge  124  above the ground surface. The bounce angle extends from the leading edge  124  to the rear edge  125  of the forward sole section  122 . The bounce angle may be as little as three degrees and as much as 12-15 degrees depending upon the overall front to rear width of the forward sole bounce section  122 , the loft and size of the club head  100 . The forward section  122  provides a frictional surface that impacts the ground when a golf ball is struck by the club head  100 . The bounce angle of the forward section  122  prevents the leading edge  124  of the club head  100  from digging into the turf or ground surface and actually causes the club head  100  to bounce slightly, thereby maintaining the club head on plane without interference with the ground.  
      The bottom sole  116  includes a mid-section  126  behind or rearward of the forward sole bounce section  122 . The mid-section  126  extends upwardly and inwardly and recesses into the club head body  102  to the extent that it is raised above the ground surface with the club head  100  at the address position. The bottom sole  116  preferably may be provided with a rear edge  128  having at least a portion that rests the club head  100  on the ground for increased stability. Raising the mid-section  126  above the ground provides less friction on the surface of the mid-section  126  since it is raised higher than the forward sole bounce section  122  that, in turn, reduces the overall friction across the bottom sole surface  116  of the club head  100  as the club head  100  is swung. The raised mid-section 126  preferably has an aerodynamic or airfoil shape that traps air between the bottom sole  116  and ground creating lift and increasing club head speed.  
      As seen in the sectional view of  FIG. 5 , the thickness of the bottom sole  116  of the club head  100  is greater than the upper portions of the club head  100  resulting in increased weight at the lower areas of the club head  100 , that, in turn, facilitates hitting a golf ball higher into the air. The bounce configuration of the forward sole section  122  allows a golfer to hit a golf ball from a flat surface, such as closely mown fairway grass or even a dirt surface, without the leading edge  124  of the club head  100  digging into the surface. Therefore a golfer may hit a driver type club, typically with a face loft angle between 8 to 12 degrees, from a flat surface without a tee. This enables a shot to be hit from a fairway lie where greater distance is needed in order to reach the green and reduces the likelihood of taking a divot that would reduce club head speed and promote a miss hit.  
      In the present embodiment, the club head  100  includes a third rear section  128  on the bottom sole  116  that touches the ground to stabilize the club head  100 .  
       FIG. 6  illustrates a series of golf club heads  200 ,  210  and  220 , representing a driver, three wood and five wood respectively. It will be appreciated that the structure of the present invention is equally applicable to any size, shape and loft metal wood. The above illustrations are illustrative only and are deemed limiting to specific shapes, sizes and lofts.  
       FIGS. 7 and 8  illustrate a golf club head  300  that is essentially the same as the club head of FIGS.  1  to  5  except for the bottom sole  316 . In this embodiment, a forward section  322  of the bottom sole  316  extends approximately half way between the leading edge  324  and the rear face  312 . The forward section  322  includes a bounce angle of a lesser degree than the bounce angle of the previous embodiment, the extended length of the forward section being sufficient to raise the ball striking face  306  of the club head  300  above the ground surface. A rear section  326  of the bottom sole  316  extends upwardly into the club head  300  so as to be raised above the ground surface to reduce friction and provide an aerodynamic airflow surface.  
       FIGS. 9 and 10  illustrate a golf club head  400  that is essentially the same as the club head of FIGS.  1  to  5  except for the bottom sole  416 . In this embodiment, the bottom sole  416  includes a forward section  422  that includes a bounce angle sufficient to raise the ball striking face  406  of the club head  400  above the ground surface. A center portion  426  of the bottom sole  416  is flat and is used to support the club head on the grass or other ground support surface prior to the execution of a golf shot. A rear section  428  of the bottom sole  416  extends upwardly into the club head  400  and is raised above the ground surface to reduce friction and provide an aerodynamic flow surface.  
       FIG. 11  and  12  illustrate still another golf club head  500  that is also essentially the same as the club head of  FIG. 1  to  5  except for the bottom sole  516 . In this embodiment, the bottom sole  516  includes a forward section  522  with a bounce angle as described herein above. A plurality of slots or channels  524  are provided between the forward section  522  and the rear face  512 . The slots  524  are oriented in a front to rear direction on the bottom sole  516 . The slots reduce friction and provide an aerodynamic flow surface for the club head  500  as it is swung during the execution of a golf shot.  
      While various embodiments have been shown and described, it will be understood there is no intent to limit the invention by such disclosure. All modifications and alternate constructions of woods and metal woods having a bottom sole with a bounce section are included within the spirit and scope of the invention as defined by the following claims.