Golf ball

Abstract

A golf ball has plural dimples provided on a surface of the golf ball; a first land part existing between the plural dimples and having as its surface a spherical surface of a sphere having the center of the golf ball as its center; a second land part having a boundary with the first land part or boundaries with the first land part and the plural dimples and having a surface having a smaller curvature than the spherical surface of the first land part; and an engraved marking disposed substantially on the second land part.

1 . A golf ball comprising:
 plural dimples provided on a surface of the golf ball;   a first land part existing between the plural dimples and having as its surface a spherical surface of a sphere having the center of the golf ball as its center;   a second land part having a boundary with the first land part or boundaries with the first land part and the plural dimples and having a surface having a smaller curvature than the spherical surface of the first land part; and   an engraved marking disposed substantially on the second land part.   
     
     
         2 . The golf ball according to  claim 1 , wherein a part of the engraved marking extends to outside from the second land part. 
     
     
         3 . The golf ball according to  claim 1 , wherein at least approximately 80% of the area of the engraved marking is within the second land part. 
     
     
         4 . The golf ball according to  claim 1 , wherein the surface of the second land part is planar. 
     
     
         5 . The golf ball according to  claim 1 , wherein the changes of a coefficient of drag CD and a coefficient of lift CL between having and not having the engraved marking are each within 0.005 at an initial ball velocity of 72 m/s and spin amount of 2800 rpm. 
     
     
         6 . The golf ball according to  claim 1 , wherein the second land part is surrounded by at least three dimples. 
     
     
         7 . The golf ball according to  claim 1 , wherein the second land part is surrounded by at most seven dimples. 
     
     
         8 . The golf ball according to  claim 1 , wherein the plural dimples comprise dimples having at least two different sizes. 
     
     
         9 . The golf ball according to  claim 8 , wherein the second land part has a smaller size than a largest dimple among the plural dimples. 
     
     
         10 . The golf ball according to  claim 8 , wherein the second land part has a greater size than a smallest dimple among the plural dimples. 
     
     
         11 . The golf ball according to  claim 8 , wherein a maximum length of the engraved marking is smaller than approximately 1.2 times a maximum length of a largest dimple among the plural dimples. 
     
     
         12 . The golf ball according to  claim 1 , comprising at least two of the engraved markings 
     
     
         13 . The golf ball according to  claim 1 , comprising one or more of the engraved markings, wherein the number of dimples surrounding the one or more engraved markings is at most approximately 30% of the total number of dimples formed on the golf ball. 
     
     
         14 . The golf ball according to  claim 1 , wherein a deepest point from the surface of the second land part to a bottom of the engraved marking is at least approximately 0.05 mm. 
     
     
         15 . The golf ball according to  claim 1 , wherein a deepest point from the surface of the second land part to a bottom of the engraved marking is at most approximately 0.2 mm. 
     
     
         16 . The golf ball according to  claim 1 , wherein the engraved marking comprises a symbol related to golf or ball. 
     
     
         17 . The golf ball according to  claim 1 , wherein the engraved marking comprises a word related to golf or ball.