Patent ID: 6634960
Filing Date: 2003-10-21
Classification: A63B

Abstract:
A thread wound golf ball comprising a solid center, a thread rubber layer formed on the solid center, and a cover covering the thread rubber layer, of which the cover has many dimples on the surface thereof, whereinthe solid center has a diameter of 35 to 38 mm and a deformation amount of 0.78 to 1.36 mm when applying from an initial load of 9.8 N to a final load of 294 N, the thread rubber layer has a thickness of 1.0 to 2.5 mm, the cover has a Shore D hardness of 40 to 55, and a dimple volume rate RV (%) and the cover hardness (CD) in Shore D hardness satisfy a correlation represented by the following formula (1): 36&lE;(CDÃ—RV)&lE;42â€ƒâ€ƒ(1) â€ƒwherein the dimple volume rate RV is represented by the following formula: RV(%)=VT/VGÃ—100 â€ƒwherein VT (mm3) is a dimple total volume, which is the sum of a volume of a space defined by a concave of the dimple and a tangent plane passed through an opening of the dimple, and VG is a volume of the golf ball assuming that it is a true sphere having no dimples on the surface thereof.