Golf club

Abstract

A golf club enables a golf ball to be hit farther without a decrease in ball traveling distance even if it is struck at a lower point on the club head face. A driver club head includes a face having a hitting surface, a sole forming the bottom of the head, etc. The sole is modified for improvement by providing an elastically deformable area having a recessed or projected configuration at a position of the sole closer to the face. The deformable area includes a bent portion formed at the lower end of the face. A bend is formed between the bent portion and the sole at an obtuse angle. The sole is provided with a recess or a projection to lower the rigidity of the sole. Thus, repulsion is enhanced to increase the ball traveling distance even if the ball is struck at a lower point on the face.

What is claimed is:  
     
         1 . A golf club having a metallic hollow golf club head, said golf club comprising: 
 a face member disposed at a front of said club head and having a hitting surface for hitting a golf ball; and    a head body member constituting a remaining part of said club head, said head body member including:    a sole forming a bottom of said club head;    a crown forming a top of said club head;    a toe forming a forepart of said club head;    a heel forming a rear part of said club head;    a back positioned opposite said face member to form a back part of said club head; and    a hosel to which a club shaft is connected;    wherein a deformable area that is elastically deformable in response to hitting of the golf ball on said hitting surface is provided at a joint between a lower end of said face member and said sole.    
     
     
         2 . A golf club according to  claim 1 , wherein said deformable area includes a lower end portion of said face member that is bent at an angle not less than 90 degrees to form a bent portion, said sole being joined to said bent portion, said sole being convexly projected toward the top of said club head in a section taken along a vertical plane containing a line perpendicular to said hitting surface.  
     
     
         3 . A golf club according to  claim 1 , wherein said deformable area includes a lower end portion of said face member that is bent at an angle not less than 90 degrees to form a bent portion, said sole being jointed to said bent portion, said sole being convexly projected away from the top of said club head in a section taken along a vertical plane containing a line perpendicular to said hitting surface.  
     
     
         4 . A golf club according to  claim 1 , wherein said deformable area includes a lower end portion of said face member that is bent at an angle not less than 90 degrees to form a bent portion, said sole being joined to said bent portion, said sole being provided with at least one hole.  
     
     
         5 . A golf club according to  claim 1 , wherein said deformable area includes a lower end portion of said face member that is bent at an angle not less than 90 degrees to form a bent portion, said sole being joined to said bent portion, said sole having a part thereof replaced with a thin plate.  
     
     
         6 . A golf club according to  claim 1 , wherein said deformable area includes a lower end portion of said face member that is bent at an angle not less than 90 degrees to form a bent portion, said sole being joined to said bent portion, said sole being divided into two portions at a part thereof, said two portions being displaceable relative to each other.  
     
     
         7 . A golf club according to  claim 2  or  3 , wherein said sole in said deformable area has a smaller plate thickness than that of said bent portion.  
     
     
         8 . A golf club according to  claim 2 , wherein a part of said sole in said deformable area forms an arch-shaped groove.  
     
     
         9 . A golf club according to  claim 2 , wherein a portion of said sole that is joined to said bent portion in said deformable area forms a groove having a surface approximately parallel to said hitting surface.  
     
     
         10 . A golf club according to  claim 7 , wherein said deformable area has a gentle bend G formed by intersection of a line S 1  tangent to a surface of said face member with a line S 2  tangent to said bent portion, said bend G having an angle α not less than 90 degrees, and a gentle bend H formed by intersection of said tangent line S 2  with a line S 3  tangent to a surface of said sole, said bend H having an angle α 1  not less than 90 degrees.  
     
     
         11 . A golf club according to  claim 10 , wherein said deformable area has at least one arch-shaped groove provided in a surface of said sole near said bend H, and wherein a gentle bend J is formed by intersection of a line S 4  tangent to said groove with said tangent line S 2 , said bend J having an angle α 2  not less than 90 degrees, and a gentle bend K is formed by intersection of a line S 5  tangent to said groove with said tangent line S 31  said bend K having an angle α 3  not less than 90 degrees, wherein said bend G, said bend J and said bend K form a continuous gently curved line.  
     
     
         12 . A golf club according to  claim 10  or  11 , wherein the angle α of said bend G is not less than 90 degrees and not more than 135 degrees, preferably not less than 90 degrees and not more than 120 degrees.