Patent Publication Number: US-2012040773-A1

Title: Sole for iron golf club head

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The Present Application is a continuation application of U.S. Pat. No. 12/616503, filed on Nov. 11, 2009, which claims priority to U.S. Provisional Patent Application No. 61/117030, filed on Nov. 21, 2008, now abandoned, both of which are hereby incorporated by reference in their entireties. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an iron-type golf club heads. More specifically, the present invention relates to a new sole design for an iron-type golf club head to improve turf contact and divot taking. 
     2. Description of the Related Art 
     The prior art discloses sole designs for golf club heads. 
     The Golf club sole and the leading edge have meaningful effects on how well the club head maintains speed and direction. For many clubs and shots it is desirable to impact the ball just before the club down swing is complete, this to achieve improved spin for the situation. To achieve this, the club has to contact the ball and transfer energy to the ball near simultaneously with the turf. Should the club pass through the turf before the energy is transferred to the ball, the ball speed and spin are diminished. 
     Also, on contact with the turf, particularly in a downward hit, the impact can be felt as harsh by the golfer. Some golfers become timid about swinging the club toward the turf and attempt to pick the ball off the turf without contact. In general, a divot is taken to allow the club head to contact the ball in the most advantageous orientation. Contacting the ball just prior to the ground is the intent, but for most golfers there are errors in delivering the ball. It is preferable that the club head&#39;s path follow through the turf. Often the club head impacts the turf before the ball due to variation in the swing path and, or because the ball lies in the turf such that ball and turf must be hit for the most advantage. Event he best of players require this shot at times. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention resolves the problems of the prior art. 
     Golfers gain advantage by reducing variation of the ball flight. Executing the require swing and impact is necessary for the best results. There are variations in the swing and in the contact location of the club, ball impact. The mass properties of the club head are tailored to achieve the mass properties to minimize the impact of variations in the swing. Common faults and common expectations can be identified and details of the club design such as mass properties and the geometry of the head are used to better serve the identifiable segments. The mass properties designer to better an identified segment can be achieved in various geometries and constructions. These geometries also affect the many other properties of the club head. This invention enables the construction of club heads that simultaneously improve geometry driven mass properties, aesthetic appeal and forces during impact. Some of the impact forces degrade the head, ball impact orientation and speed Impact can also result in harshness felt in the golfer&#39;s hands. 
     The purpose of this invention is to minimize the impact variations, allow preferred geometries for specific mass properties, turf impact and functional and aesthetic appeal. 
     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 perspective view of an iron golf club head. 
         FIG. 2  is a perspective view of an iron golf club head. 
         FIG. 3  is a perspective view of an iron golf club head. 
         FIG. 4  is a perspective view of an iron golf club head. 
         FIG. 5  is a partial cross-sectional view of an iron golf club head. 
         FIG. 6  is a perspective view of an iron golf club head. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIGS. 1-10 , an iron-type golf club head in accordance with the present invention is generally designated  20 . The club head  20  is a cavity-back iron and includes a body  22  having a heel end  24  and a toe end  26 . The body  22  has a front wall  28  for contacting a golf ball and a hosel  30  for receiving a shaft, not shown. In a preferred embodiment the golf club head  20  is composed of a stainless steel, however, those of ordinary skill in the art will appreciate that the golf club head  20  may also be composed of other materials, such as carbon steel, titanium, titanium alloy, zirconium or zirconium alloy. 
     The front wall  28  of golf club head  20  has a ball-striking surface  40  and a back surface  42 . The ball-striking surface  40  has a plurality of scorelines  44  formed therein. In a preferred embodiment the top of the hosel  30  is lower than the toe end of the front wall  28 , thereby lowering the center of gravity of the club head  20 . 
     The golf club head  20  also has a top portion  46 , a sole portion  48 , a heel portion  50 , a toe portion  52  and a rear surface  54 . The top wall  46  extends rearward from the top end of the front wall  28 , in a direction opposite the ball-striking surface  40 , to the rear surface  54  of the body  22 . The sole portion  48  extends rearward from the bottom end of the front wall  28  to the rear surface  54 . The heel portion  50  extends rearward from the heel end  24  of the front wall  28  to the rear surface  54 , and the toe portion  52  extends rearward from the toe end  26  of the front wall  28  to the rear surface  54 . The rear surface  54 , the top portion  46 , the sole portion  48 , the heel portion  50  and the toe portion  52  define an external rear cavity  56  in the body  22  of the club head  20 . The top portion  46 , the sole portion  48 , the heel portion  50  and the toe portion  52  also provide the club head  20  with perimeter weighting to make the club head more forgiving and provide better performance for the typical golfer. 
     The golf club head  20  preferably includes an undercut recess  68  in communication with the external rear cavity  56 . The undercut recess  68  preferably circumscribes the external rear cavity  56 . Alternatively, the undercut recess  68  may extend along only a portion of the external rear cavity  56 . A medallion, not shown, is preferably disposed in the external rear cavity  56  of the body  22 . 
     As shown in  FIGS. 1-6 , the present invention creates a geometry that is aesthetically pleasing, consistent with the best mass properties and accommodating to the golfers interest in sole shapes that minimize interference between the turf and club head. This is accommodated by combining features of better player clubs and with improving player clubs. The radius of the face to sole transition is designed to be a smaller radius to maximize the extension of the flat face within the ball contact locations. Also the radius design penetrated the turf better than a more blunt face to sole transition. 
     The sole is extended away from the face to improve the mass properties of the center of mass, the mass distribution, appeal, and for clearance between the club head and the turf during the follow through of the swing. The sole is stepped such that the sole surface furthest from the face is raised away from the turf to minimize the turf contact through the swing particularly for the longer, less lofted “irons”. The surface friction is reduced by applying a thin dense chromium coating thorough electroplating. 
     The appeal of the step and associated geometry is detailed for both appearance and preferential shape. 
     The invention creates a unique combination of head shape and surface friction coefficients that minimize the bad effects of turf impact. 
     Further, this invention creates a geometry that is aesthetically pleasing, consistent with the best mass properties and accommodating to the golfers interest in sole shapes that minimize interference between the turf and club head. This is accommodated by combining features of better player clubs and with improving player clubs. The radius of the face to sole transition is designed to be a smaller radius to maximize the extension of the flat face within the ball contact locations. Also the radius design penetrated the turf better than a more blunt face to sole transition. 
     The sole is extended away from the face to improve the mass properties of the center of mass, the mass distribution, appeal, and for clearance between the club head and the turf during the follow through of the swing. The sole is stepped such that the sole surface furthest from the face is raised away from the turf to minimize the turf contact through the swing particularly for the longer, less lofted “irons”. 
     The step geometry is also aesthetically advantageous. 
     An iron-type golf club head in accordance with the present invention is generally designated. The club head is a cavity-back iron and includes a body having a heel end and a toe end. The body has a front wall for contacting a golf ball and a hosel for receiving a shaft, not shown. The hosel has a bore with an ingress opening and optionally an egress opening. In a preferred embodiment the golf club head is composed of a stainless steel, however, those of ordinary skill in the art will appreciate that the golf club head may also be composed of other materials, such as carbon steel, titanium, titanium alloy, zirconium or zirconium alloy. 
     The front wall of golf club head has a ball-striking surface and a back surface. The ball-striking surface has a plurality of scorelines formed therein. In a preferred embodiment the top of the hosel is lower than the toe end of the front wall, thereby lowering the center of gravity of the club head. 
     The golf club head also has a top wall, a bottom wall, a heel wall, a toe wall and a rear surface. The top wall extends rearward from the top end of the front wall, in a direction opposite the ball-striking surface, to the rear surface of the body. The bottom wall extends rearward from the bottom end of the front wall to the rear surface. The heel wall extends rearward from the heel end of the front wall to the rear surface, and the toe wall extends rearward from the toe end of the front wall to the rear surface. The rear surface, the top wall, the bottom wall, the heel wall and the toe wall define an external rear cavity in the body of the club head. The top wall, the bottom wall  48 , the heel wall and the toe wall also provide the club head with perimeter weighting to make the club head more forgiving and provide better performance for the typical golfer. 
     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.