Golf ball having comma-shaped dimples
In a golf ball including dimples having coma shapes, the dimples are arranged such that one comma shaped dimple replaces a circular dimple, two or more comma shaped dimples of different sizes replace one circular dimple, comma shaped dimples having different shapes are arranged in a mixed type arrangement, circular dimples and comma shaped dimples are arranged in a mixed type arrangement, or a discontinuous annular dimple is added to the comma shaped dimples. Thus, a disadvantage of a large circular dimple may be removed and simultaneously a golf ball with stable flight capability and a long flight distance may be provided.
1. A golf ball in which a surface of a sphere is divided into a spherical polyhedron and dimples are formed in each divided surface of the spherical polyhedron,
wherein a plurality of circular unit cells are formed in each surface;
each circular unit cell comprising at least two dimples having different sizes that are formed in each of the plurality of circular unit cells, each dimple having a comma shape, the comma shape comprises a circular head portion and a tail portion extending from the head portion and having a width that gradually decreases as the tail portion bends in one direction, and an outer contour of the comma shape, which comprises
a first curved line formed of an arc coinciding with an outer contour of the circular unit cell;
a second curved line extending from one end portion of two end portions of the first curved line with a radius of curvature ROC smaller than a ROC of the first curved line and forming an outer contour of the head portion; and
a third curved line extending toward an end point of the comma shape to the other end portion of the second curved line and forming an outer contour of the tail portion with the first curved line,
wherein, an inner land portion is between the at least two dimples, the inner land portion being lower than a sphere surface of the golf ball and higher than bottoms of the at least two dimples having comma shapes,
wherein the end point of the comma shape of each dimple is proximate to a head portion of an adjacent dimple.
2. The golf ball of claim 1 , wherein a frustum depth is defined a distance between a base plane that contacts a bottom of the comma dimple and a top plane that is parallel to the base plane and passes a border of the dimple, and
the frustum depth is in a range of 0.05 mm to 0.2 mm.
3. The golf ball of claim 1 , wherein a frustum depth is defined a distance between a base plane that contacts a bottom of the dimple and a top plane that is parallel to the base plane and passes a border of the dimple, and
a height of a sphere surface, “hs”, is a distance between a tangent line of the sphere surface and the top plane of the frustum depth,
a height of an inner land surface, “hl”, is a distance between an inner land surface line and the top plane of the frustum depth, and
hl and hs are in the range of 0.05 mm to 0.2 mm, while hl is equal to or smaller than hs.
4. The golf ball of claim 1 , further comprising
a set of additional dimples in the form of a ring that are discontinuously arranged formed over adjacent dimples in adjacent unit cells.
5. A golf ball in which a surface of a sphere is divided into a spherical polyhedron and dimples are formed in each divided surface of the spherical polyhedron, wherein a plurality of elliptical unit cells are formed in each surface;
each elliptical unit cell comprising at least two dimples having different sizes that are formed in each of the plurality of elliptical unit cells, each dimple having a comma shape, the comma shape comprises a circular head portion and a tail portion extending from the head portion and having a width that gradually decreases as the tail portion bends in one direction, and an outer contour of the comma shape, which comprises
a first curved line formed of an arc coinciding with an outer contour of the elliptical unit cell;
a second curved line extending from one end portion of two end portions of the first curved line with a radius of curvature ROC smaller than a ROC of the first curved line and forming an outer contour of the head portion; and
a third curved line extending toward an end point of the comma shape to the other end portion of the second curved line and forming an outer contour of the tail portion,
wherein, an inner land portion is between at least two dimples, the inner land portion being lower than a sphere surface of the golf ball and higher than bottoms of the at least two dimples having comma shapes, wherein the end point of the comma shape of each dimple is proximate to a head portion of an adjacent dimple.
6. The golf ball of claim 5 , wherein a frustum depth is defined a distance between a base plane that contacts a bottom of the dimple and a top plane that is parallel to the base plane and passes a border of the dimple, and
the frustum depth is in the range of 0.05 mm to 0.2 mm.
7. The golf ball of claim 5 , wherein a frustum depth is defined a distance between a base plane that contacts a bottom of the comma dimple and a top plane that is parallel to the base plane and passes a border of the dimple,
a height of sphere surface, “hs”, is a distance between a tangent line of the sphere surface and the top plane of the frustum depth,
a height of inner land surface, “hl”, is a distance between an inner land surface line and the top plane of the frustum depth, and
hl and hs are in the range of 0.05 mm to 0.2 mm, while hl is equal to or smaller than hs.
8. The golf ball of claim 5 , further comprising
a set of additional dimples in the form of a ring that are discontinuously arranged formed over adjacent dimples in adjacent unit cells.