Golf club head

Abstract

The head of a golf club is improved by reducing the drag and wake turbulence produced in the air when the golf club is swung to strike a golf ball. The club head has a convex sole with an elongated depression defined therein. The inboard end of the depression is located proximate both the heel and the ball-impact face and extends outwardly at a diverging angle from the ball-impact face to an outboard extremity located inboard from the toe of the club head. This depression or channel is thereby closely aligned with the direction of travel of the club head during a normal downswing and follow through of a golf stroke. Also, the top of the club head is covered with a relatively rough coating, such as a textured paint with granules encapsulated therein. The roughness average of the top surface of the club head, as measured by a profilometer, is it least three times as great as that of the ball-impact face and at least three times as great as that of the sole of the club head.

I claim:  
     
         1 . In a golf club head having a ball-impact face, a sole, a top, a back, a heel, a toe, and a hozzle, the improvement wherein a depressed channel is defined in said sole and extends from an inboard extremity thereof proximate both said heel and said ball-impact face outwardly at a diverging angle from said ball-impact face to an outboard extremity located inboard from said toe.  
     
     
         2 . A golf club head according to  claim 1  further characterized in that said ball-impact face is substantially flat and said channel is aligned at an angle of between about thirty degrees and about sixty degrees relative to said ball-impact face.  
     
     
         3 . A golf club head according to  claim 2  wherein said channel is between about two centimeters and about three centimeters in width and is aligned at an angle of about forty-five degrees relative to said ball-impact face.  
     
     
         4 . A golf club head according to  claim 1  wherein said channel is between about two millimeters and about four millimeters in maximum depth, between about five centimeters and about seven centimeters in length and between about two centimeters and about three centimeters in maximum width.  
     
     
         5 . In a golf club head having a ball-impact face, a sole having a convex surface, a top, a back, a heel, a toe, and a hozzle, the improvement wherein an elongated concave depression is defined in said convex surface of said sole and said concave depression is aligned to extend from a location at said heel and proximate said ball-impact face away from said heel and at an acute angle of between about thirty degrees and about sixty degrees relative to said ball-impact face and said concave depression terminates inboard from said toe.  
     
     
         6 . A golf club head according to  claim 5  wherein said depression is between about two millimeters and about four millimeters in maximum depth, between about five centimeters and about seven centimeters in length and between about two centimeters and about three centimeters in maximum width.  
     
     
         7 . A golf club head according to  claim 6  wherein said depression is aligned at an angle of between about forty-five degrees and about fifty-five degrees relative to said ball-impact face.  
     
     
         8 . A golf club head according to  claim 6  wherein said depression is aligned at an angle of about fifty degrees relative to set ball-impact face.  
     
     
         9 . A golf club head according to  claim 8  wherein said ball-impact face has an arithmetic mean of profile roughness of between about 0.67 microns and about 0.81 microns, said sole has an arithmetic mean of profile hardness of between about 0.82 microns and about 1.1 microns, and said top has an arithmetic mean of profile roughness at least about three times as great as that of said ball-impact face and at least about three times as great as that of said sole.  
     
     
         10 . A golf club head according to  claim 9  wherein said top has an arithmetic mean of profile roughness of between about 3.3 microns and about 3.9 microns.  
     
     
         11 . A golf club head according to  claim 10  wherein said back also has an arithmetic mean of profile roughness of between about 3.3 microns and about 3.9 microns.  
     
     
         12 . In a golf club head having a ball-impact face, a sole, a top, a back, a heel, a toe, and a hozzle, the improvement wherein said ball-impact face has an arithmetic mean of profile roughness of between about 0.67 microns and about 0.81 microns, said sole has an arithmetic mean of profile roughness of between about 0.82 microns and about 1.1 microns, and said top has an arithmetic mean of profile roughness at least about three times as great as that of said ball-impact face and it least about three times as great as that of said sole.  
     
     
         13 . A golf club head according to  claim 12  wherein said top has an arithmetic mean of profile roughness of between about 3.3 microns and about 3.9 microns.  
     
     
         14 . A golf club head according to  claim 13  wherein said back also has an arithmetic mean of profile roughness of between about 3.3 microns and about 3.9 microns.  
     
     
         15 . A golf club head according to  claim 12  wherein said sole is formed with a convex surface that extends to said heel, said toe, said back, and said ball-impact face, and an elongated, concave depression is defined in said convex surface of said sole and said concave depression is aligned to extend from a location at said heel and proximate said ball-impact face away from said heel and at an acute angle of between about thirty-five degrees and about sixty-five degrees relative to said ball-impact face.  
     
     
         16 . A golf club head according to  claim 15  wherein said depression is between about two millimeters and about four millimeters in maximum depth, between about five centimeters and about seven centimeters in length, and between about two centimeters and about three centimeters in maximum width.  
     
     
         17 . A golf club head according to claim to  16  wherein said depression is aligned at an angle of about forty-five degrees relative to said ball-impact face.