GOLF BALL

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. § 119 (a) on Patent Application No. 2024-220845 filed in Japan on Dec. 17, 2024, the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a golf ball having a land portion and a large number of dimples formed on a ball surface.

BACKGROUND ART

In a golf ball, it is well known that high rebound provided in the ball itself and reduction of air resistance during flight by dimples disposed on a ball surface are important in order for a struck ball to obtain a long distance, and various methods for arranging the dimples as densely and evenly as possible on the ball surface have been proposed for the purpose of reducing air resistance.

Typically, a design of the dimples of a golf ball takes an approach of disposing dimples of a predetermined shape or shapes on the ball surface. However, in such a method of disposing dimples having a predetermined shape, if a surface occupancy ratio of the dimples is very high, since the surface of the golf ball is spherical, it is difficult to evenly dispose the dimples, a place where gaps between the dimples are widened or narrowed occurs, and the gaps between the dimples are often uneven. If the gaps between the dimples are uneven, even if the dimples have a high surface occupancy ratio, an aerodynamic performance of the golf ball may be extremely poor.

For example, Patent Document 1 (JP-A 2004-105200) describes forming a ridge-shaped protrusion on the surface of a golf ball, which is completely different from a conventional concept of forming a large number of dimples on the surface of a golf ball. It is described that by forming the ridge-shaped protrusion in this way, an occupancy ratio of a portion without the protrusion corresponding to the surface occupancy ratio of the conventional dimples may be easily increased, and the aerodynamic performance may be improved.

In addition, Patent Document 2 (JP-A 2011-031043) proposes a golf ball including a plurality of dimples and a land portion surrounded by the plurality of dimples, in which the land portion has a shape having at least one vertex, the land portion is substantially in point contact with at least two adjacent land portions, and a surface area of the land portion is within a predetermined range. That is, in the golf ball, since the land portion has a specific shape, even if a surface occupancy ratio of the dimples is increased, the gaps between the dimples may be evenly maintained, the aerodynamic performance is improved, and the distance is increased.

However, there is a demand for a golf ball having a novel land portion shape and a dimple shape on the ball surface, which may improve the aerodynamic performance due to the dimple and may improve the distance more than the above proposed golf balls.

CITATION LIST

• • Patent Document 1: JP-A 2004-105200
  • Patent Document 2: JP-A 2011-031043

SUMMARY OF THE INVENTION

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a golf ball that, as compared with the related art, may improve aerodynamic performance due to dimples and increase a distance and has a novel ball surface.

As a result of intensive studies to achieve the above object, the present inventors have focused on a shape of a land portion on an outside surface of a ball instead of focusing on dimples in order to increase a surface occupancy ratio of the dimples, and have optimized the shape, thereby completing the present invention. That is, the present inventors have found that it is possible to solve the above-described problems to be solved by the present invention by creating a land portion piece, which is the smallest unit of the land portion on the outside surface of the ball and has at least three vertices in the shape of the land portion piece, the land portion piece having a specific shape formed by connecting the land portion piece substantially in point contact with another adjacent land portion piece at each of the vertexes, and further, by adjusting a shape of an outer peripheral edge of the land portion piece such that a ratio of the number of land portion pieces having a unique shape in which all edge elements are formed by a curve having a curvature of not more than 0.40 or 0.35 is at least 30% or at least 20% of a total number of land portion pieces constituting the land portion for finishing a plurality of the edge elements forming the outer peripheral edge of the land portion piece as edge elements having a low-curvature curve, and have completed the present invention.

Accordingly, the present invention provides a golf ball including

• • a plurality of dimples and a land portion surrounded by the plurality of dimples, wherein the land portion includes a large number of land portion pieces, one land portion piece has a shape having at least three vertexes, and the land portion includes a land portion piece having a specific shape formed by connecting the land portion piece substantially in point contact with another adjacent land portion piece at each of the vertexes, an outer peripheral edge of the land portion piece having the specific shape includes a plurality of edge elements, and a ratio of the number of land portion pieces having a unique shape in which all the edge elements are formed by a curve having a curvature of not more than 0.40 is at least 30% of the total number of land portion pieces constituting the land portion.

In a preferred embodiment of the golf ball according to the invention, the ratio of the number of land portion pieces having a unique shape in which all the edge elements are formed by a curve having a curvature of not more than 0.40 is at least 50% of the total number of land portion pieces constituting the land portion.

In another preferred embodiment of the inventive golf ball, the golf ball includes a plurality of dimples and a land portion surrounded by the plurality of dimples, wherein the land portion includes a large number of land portion pieces, one land portion piece has a shape having at least three vertexes, and the land portion includes a land portion piece having a specific shape formed by connecting the land portion piece substantially in point contact with another adjacent land portion piece at each of the vertexes, an outer peripheral edge of the land portion piece having the specific shape includes a plurality of edge elements, and a ratio of the number of land portion pieces having a unique shape in which all the edge elements are formed by a curve having a curvature of not more than 0.35 is at least 20% of the total number of land portion pieces constituting the land portion.

In yet another preferred embodiment, the ratio of the number of land portion pieces having a unique shape in which all the edge elements are formed by a curve having a curvature of not more than 0.35 is at least 30% of the total number of land portion pieces constituting the land portion.

In still another preferred embodiment, a peripheral edge portion of the land portion piece having the unique shape includes six curved edge elements.

In a further preferred embodiment, the land portion is formed by connecting at least 4,000 curved edge elements.

In a yet further preferred embodiment, a ratio of edge elements having a curvature of not more than 0.40 is at least 70% of the curved edge elements forming the land portion.

In a still further preferred embodiment, the golf ball has at least eight circular dimples.

In another preferred embodiment, a ratio of circular dimples to a total number of the dimples is not more than 10%.

In yet another preferred embodiment, a total dimple volume under a flat plane circumscribed by an outer peripheral edge of the dimples is from 300 to 600 mm³.

In still another preferred embodiment, at least three types of the land portion pieces having different sizes or shapes are used.

In a further preferred embodiment, the number of the dimples is 200 to 500.

In a yet further preferred embodiment, the dimples have a surface area occupancy ratio of from 60 to 95%.

Advantageous Effects of the Invention

As compared with the related art, the golf ball of the present invention can improve an aerodynamic performance due to the dimples and increase a distance, and exhibits a novel ball appearance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a golf ball of Examples 1 to 3 which are embodiments of the present invention.

FIG. 2A is a partially enlarged view showing a ball surface in FIG. 1, and FIG. 2B is a schematic view showing only a land portion in FIG. 2A.

FIG. 3 is a schematic view showing a golf ball of Comparative Example 2.

FIG. 4A is a partially enlarged view showing a ball surface in FIGS. 3 and 5, and

FIG. 4B is a schematic view showing only a land portion in FIG. 4A.

FIG. 5 is a schematic view showing a golf ball of Comparative Example 3.

FIG. 6 is a schematic view showing a golf ball of Comparative Example 1.

FIG. 7 is a partially enlarged view showing a ball surface in FIG. 6.

FIG. 8A is a schematic perspective view of an injection mold (lower mold) of Example 1, and FIG. 8B is a schematic plan view of the mold as viewed from above.

FIG. 9A is a schematic enlarged view obtained by enlarging a vicinity of a parting line of the mold of FIG. 8, and FIG. 9B is a schematic view showing a shape of an opening portion of a gate portion.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention is described in more detail.

A golf ball of the present invention includes a plurality of dimples and a land portion surrounded by the plurality of dimples. The land portion means a portion of a ball surface where no dimple is formed. A boundary line between the land portion and the dimple corresponds to an outer peripheral edge of the land portion or an outer peripheral edge of the dimple, and is referred to as an edge portion or an edge element in the present invention.

The land portion includes a large number of land portion pieces. For example, FIG. 1 shows a plan view of a golf ball of Examples 1 to 3 according to an embodiment of the present invention. The golf ball has a large number of dimples D and land portions L. An enlarged view of an area T among the dimples D and the land portions L is shown in FIG. 2A, and a large number of land portion pieces 10 that are minimum units of the land portions L are formed. That is, six land portion pieces 10 are formed around one dimple D. As a result, the outer peripheral edge of the dimple D has a substantially dodecagonal shape. Sides between vertexes of the substantially dodecagonal polygon are not straight but curved.

As shown in FIGS. 2A and 2B, the land portion piece 10 has a trifurcated shape (a shape radially extending in three directions and separated by about 120 degrees), and each extending portion extending radially is gradually narrowed outward and has a pointed tip. This pointed portion is a vertex 1a, that is, one land portion piece 10 has three vertexes 10b, and is substantially in point contact with another land portion piece adjacent to the land portion piece at the vertex. The outer peripheral edge of one land portion piece 10 includes six edge elements 10a. In other words, the six edge elements are connected to each other, so that the land portion piece has the above-described trifurcated shape.

In the present invention, the shape of the land portion piece is not limited to the above-described trifurcated shape, and may be, for example, a Y shape, a T shape, a star shape, or the like, as long as the land portion piece has a shape having at least three vertexes, and has a specific shape that is substantially in point contact with and connected to another adjacent land portion piece at each of the vertexes. The land portion piece is not limited to only one type, and two or more types having different sizes or shapes may be used.

In the present invention, in the land portion piece, the edge element is preferably formed by a curve having a curvature of not more than 0.40. In the present invention, by using a curve having a curvature of not more than 0.40 as the edge element, novelty of a ball surface (appearance) and an optimum shape of aerodynamic performance are configured, and a distance is increased. The curvature of the edge element is preferably not more than 0.40, more preferably not more than 0.35, and still more preferably not more than 0.30. In this way, the curvature of each edge element is set to be small as described above in order to avoid a shape creating air resistance as much as possible with respect to a shape of an inner peripheral side surface (edge) of the dimple.

A ratio of the number of land portion pieces in which all the edge elements are formed by a curve having a curvature of not more than 0.40 is preferably at least 30%, more preferably at least 40%, and still more preferably at least 50% of a total number of land portion pieces constituting the land portion.

The ratio of the number of land portion pieces in which all the edge elements are formed by a curve having a curvature of not more than 0.35 is preferably at least 20% and more preferably at least 30% of the total number of land portion pieces constituting the land portion.

In the present invention, it is preferable that the number of curves to be edge elements is at least 4,000 as a whole. A ratio of the edge elements having a curvature of not more than 0.40 in the curved edge elements forming the land portion is preferably at least 70%, and more preferably at least 75%. By increasing a ratio of the curves having not more than the predetermined curvature in this manner, it is possible to reduce air resistance on the ball surface and to further increase the distance.

A surface area of the land portion piece 10 is preferably at least 0.05 mm², more preferably at least 0.5 mm², and still more preferably at least 0.62 mm², and an upper limit is preferably not more than 16.0 mm², more preferably not more than 8.5 mm², and still more preferably not more than 1.65 mm².

A length of an outer periphery of the land portion piece 10 is preferably at least 1.6 mm, and more preferably at least 4.0 mm, and the upper limit is preferably not more than 19.4 mm, and more preferably not more than 9.9 mm.

A length of an outer periphery of the dimple D is preferably at least 3.2 mm, and more preferably at least 6.3 mm, and the upper limit is preferably not more than 38.8 mm, and more preferably not more than 19.8 mm. By setting the length of the outer periphery of the dimple within the above range, it is possible to improve aerodynamic performance by designing the land portion as described above.

A surface of the land portion L forms a spherical surface of the golf ball, and a surface of the dimple D is recessed from a virtual spherical surface assumed to have no dimples on the surface of the golf ball, and has a shape of a smooth curved surface from a boundary line with the land portion L toward the center of the dimple, which is a position where a depth of the dimple is the deepest.

Regarding the depth of the dimple D, although the present invention is not particularly limited, the depth at the center, which is the deepest position, is, for example, preferably at least 0.05 mm, and more preferably at least 0.10 mm, and the upper limit is preferably not more than 0.45 mm, and more preferably not more than 0.35 mm.

In this way, land portion pieces having a predetermined shape are disposed on the golf ball, the dimples on the ball surface are designed, and a plurality of land portion pieces are arranged such that the adjacent land portion pieces are substantially in point contact with each other, whereby gaps between the dimples may be made even, even if a ratio of the surface of the dimple to the virtual spherical surface of the golf ball, that is, a surface occupancy ratio of the dimples, is increased. Therefore, the aerodynamic performance of the golf ball is significantly improved, and a longer distance may be obtained. In addition, the surface occupancy ratio of the dimples may be easily controlled by changing the shape of the land portion piece.

The surface occupancy ratio of the dimples is preferably at least 60%, and more preferably at least 70%. By setting the surface occupancy ratio of the dimples to at least 60%, air resistance can be reduced. On the other hand, the surface occupancy ratio of the dimples is preferably not more than 95%. Specifically, the surface occupancy ratio of the dimples means a ratio (SR value) of a total dimple surface area defined by a surface edge of a flat plane circumscribed by an edge of the dimple to a spherical surface area of the ball assuming that no dimples exist.

The total number of land portion pieces formed on the surface of the golf ball is preferably at least 434, and more preferably at least 540. On the other hand, a total number of land portions 12 is preferably not more than 864, and more preferably not more than 756. By setting the total number of land portion pieces within such a range, the surface occupancy ratio of dimples on the ball surface may be designed within the above preferable range.

A total number of dimples formed on the ball surface is usually from 200 to 500, although the total number is determined according to the total number of land portion pieces and a relationship between the land portions and the dimples. For example, in a case where the total number of land portion pieces is 434, if one dimple is formed by six land portion pieces, the total number of dimples is 218. Similarly, if one dimple is formed by six land portion pieces, in a case where the total number of land portion pieces is 540, the total number of dimples is 272, in a case where the total number of land portion pieces is 756, the total number of dimples is 380, and in a case where the total number of land portion pieces is 864, the total number of dimples is 434.

As for the shape of the dimples, usually, due to the disposition of the land portion pieces described above, non-circular dimples are disposed in most of the land portion pieces, although circular dimples may also be formed. In the case of having circular dimples, the number of circular dimples is preferably at least 8, and more preferably at least 10. A ratio of the circular dimples with respect to the total number of dimples is preferably not more than 10%, and more preferably not more than 5%. In this way, the dimples formed on the surface of the golf ball according to the present invention are not limited to non-circular dimples, and may also include circular dimples.

A total volume of the dimples means a sum of volumes of the individual dimples formed below the flat plane circumscribed by the edge of the dimple in all the dimples formed on one ball. The total dimple volume is not particularly limited, although the total dimple volume is preferably from 300 to 600 mm³. By adjusting the total dimple volume to the above range, it is possible to optimize and stabilize a ball trajectory on shots with a driver (W #1) and to obtain an intended distance.

An internal structure of the golf ball may be a one-piece ball or a multi-piece golf ball such as a two-piece or three-piece golf ball. In particular, the dimples of the present invention may be more effectively used for a multi-piece golf ball with a reduced spin rate. In a case where a ball is struck with a golf club for long distances, such as on shots with a driver (W #1) or a long iron, a balance between a lift and a drag of the ball being struck is appropriate in order to increase the distance, provide strength against wind, and obtain a ball with a long run. The balance between the lift and the drag of the ball being struck depends on the structure of the ball and a rubber/resin material to be used, and in particular, depends on the shape, surface area, and total number of land portion pieces to be used, the surface occupancy ratio of the dimples, and the like.

The golf ball of the present invention may be manufactured with a mold. In order to produce such a mold, 3DCAD or CAM may be used, and a method of directly three-dimensionally cutting an entire surface shape or a method of directly three-dimensionally cutting a cavity portion of the mold may be used for a reversing master mold. Finishing (trimming) may be facilitated by designing the mold such that a parting line of the mold passes through the land portion of the golf ball surface. In order to uniformly spread the land portion pieces on the spherical surface of the golf ball, it is preferable to use a disposition method of a polyhedron—for example, a 20-hedron, 12-hedron, or 8-hedron—three-fold symmetry, five-fold symmetry, or the like.

EXAMPLES

Hereinafter, the present invention is specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

Example 1 to 3 and Comparative Examples 1 to 3

A core composition was adjusted by a rubber formulation containing polybutadiene as a principal component shown in the following Table 1, and then vulcanization was performed at 155° C. for 20 minutes to produce a core having a diameter of 37.6 mm.

	TABLE 1
	Core formulation (pbw)	Common to each example

	Polybutadiene rubber	100
	Zinc acrylate	25.0
	Zinc stearate	2.0
	Organic peroxide	1.0
	Antioxidant	0.3
	Zinc oxide	28.0
	Organosulfur compound	0.4
	Details of the above core formulation are as follows.
	Polybutadiene rubber: Trade name “BR 730” (manufactured by ENEOS Materials Corporation)
	Zinc acrylate: Trade name “ZN-DA85S” (manufactured by Nippon Shokubai Co., Ltd.)
	Zinc stearate: Trade name “Zinc stearate GP” (manufactured by NOF Corporation)
	Organic peroxide: Dicumyl peroxide, trade name “Percumyl D” (manufactured by NOF Corporation)
	Antioxidant: Trade name “Nocrac MB” (manufactured by Ouchi Shinko Chemical Industrial Co., Ltd.)
	Zinc oxide: Trade name “Zinc Oxide Grade 3” (manufactured by Sakai Chemical Industry Co., Ltd.)
	Zinc salt of pentachlorothiophenol: Manufactured by Zhejiang Shou & Fu Chemtrade Co., Ltd.

Next, using an injection mold, injection molding was performed with a resin material of an intermediate layer shown in Table 2 around the core surface to form an intermediate layer having a thickness of 1.30 mm and a hardness of 50 on the Shore D hardness scale. Subsequently, using an injection mold having a large number of dimple-forming protrusions in a cavity, injection molding was performed with a resin material of a cover (outermost layer) shown in Table 2 around an intermediate layer-encased sphere to form a cover having a thickness of 1.25 mm and a hardness of 62 on the Shore D hardness scale.

	TABLE 2
	Resin formulation (pbw)	Intermediate layer	Cover

	HPF 1000	100
	Himilan AM7318		50
	Himilan AM7327		50
	Titanium oxide		4
	Details of the blending components in the above table are as follows.
	“HPF 1000”, manufactured by The Dow Chemical Company
	“AM7318” ionomer resin, manufactured by Dow-Mitsui Polychemicals Co., Ltd.
	“AM7327” ionomer resin, manufactured by Dow-Mitsui Polychemicals Co., Ltd.
	“Titanium oxide”, manufactured by Sakai Chemical Industry Co., Ltd.

[Dimples and Land Portion of Each Example]

As described above, by injecting the resin material of the cover using the injection mold having a large number of dimple-forming protrusions in the cavity, dimples and land portion pieces having a predetermined shape were formed on the surface of the cover. The details are shown in Table 1. In Table 3, a photograph of a dimple No. 1 is shown in FIG. 1, a photograph of a dimple No. 2 is shown in FIG. 3, a photograph of a dimple No. 3 is shown in FIG. 5, and a photograph of a dimple No. 4 is shown in FIG. 6.

Conditions and methods for measuring a radius of curvature of the edge element of the land portion piece formed on the ball surface of each example are as follows.

At least six curves (edge elements) constituting the shape of the land portion piece on the ball surface are analyzed to calculate the curvature of each curve. Each curve constituting the shape of the land portion piece was equally divided into sections by 20 plots, the curvature of the curve was calculated in each section, and a maximum curvature and a minimum curvature per curve were calculated. Regarding the circular dimple, the land portions (land portion pieces) sandwiched between the dimples were individually designated, and the maximum curvature and the minimum curvature of an arc of each dimple were calculated. This curvature was calculated using a method of analyzing each curve on the drawing by a computer or a method using an equation of a curve constituting the land portion piece based on the measured dimple shape. The number of curves having a maximum curvature of not more than 0.4 was counted as the curvature of the curve, and a ratio of the number of such curves to the total number of curves constituting the land portion piece was calculated.

The injection mold used in Example 1 is shown in FIG. 8. FIG. 8A is a schematic perspective view of an injection mold (lower mold) of Example 1, and FIG. 8B is a schematic plan view of the mold as viewed from above. As shown in these drawings, a mold 30 has a hemispherical cavity 31 having dimple-forming protrusions 31a and 31b corresponding to shapes of a large number of non-circular dimples and a small number of circular dimples, and a parting line (dividing surface) PL of the mold is not a straight line but has an uneven or wavy shape. In addition, six gate portions 32 for allowing the resin material of the cover to flow into the cavity are provided along the parting line of the mold.

Further, FIG. 9A is an enlarged view of a vicinity of the parting line of the mold, and the gate portion 32 is formed in a region surrounded by a round dotted line. As shown in FIG. 9B, the opening portion of the gate portion 32 has an elongated non-circular shape.

A flight of the golf ball on shots with a driver (W #1) of each example is evaluated by the following methods. The results are shown in Table 3.

[Evaluation of Flight (W #1, HS 50 m/s)]

The driver is mounted on a golf swing robot, and a spin rate and a distance traveled (total) by a ball when struck at a head speed (HS) of 50 m/s are measured. The club used is a TOUR B XD-5 Driver/loft angle 9.5° (2017 model) manufactured by Bridgestone Sports Co., Ltd. and is evaluated according to the following criteria.

[Rating Criteria]

⊚: Total compared with Comparative Example 1 is at least +3.2 m.

∘: Total compared with Comparative Example 1 is at least +2.0 m and less than +3.2 m.

Δ: Total compared with Comparative Example 1 is at least +0.8 m and less than +2.0 m.

X: Total compared with Comparative Example 1 is less than +0.8 m.

[Evaluation of Flight (W #1, HS 45 m/s)]

The driver is mounted on the golf swing robot, and the spin rate and the distance traveled (total) by a ball when struck at a head speed (HS) of 45 m/s are measured. The club is the same as described above.

[Rating Criteria]

⊚: Total compared with Comparative Example 1 is at least +3.2 m.

∘: Total compared with Comparative Example 1 is at least +2.0 m and less than +3.2 m.

Δ: Total compared with Comparative Example 1 is at least +0.8 m and less than +2.0 m.

X: Total compared with Comparative Example 1 is less than +0.8 m.

[Evaluation of Flight (W #1, HS 40 m/s)]

The driver is mounted on the golf swing robot, and the spin rate and the distance traveled (total) by a ball when struck at a head speed (HS) of 40 m/s are measured. The club is the same as described above.

[Rating Criteria]

⊚: Total compared with Comparative Example 1 is at least +3.2 m.

∘: Total compared with Comparative Example 1 is at least +2.0 m and less than +3.2 m.

Δ: Total compared with Comparative Example 1 is at least +0.8 m and less than +2.0 m.

X: Total compared with Comparative Example 1 is less than +0.8 m.

	TABLE 3
	Example	Comparative Example

	1	2	3	1	2	3

Dimples	Type	No. 1	No. 1	No. 1	No. 4	No. 3	No. 2
	Surface area occupancy ratio: SR (%)	92	92	92	80	90	90
	Quantity	338	338	338	326	326	338
	Number of circular dimples	14	14	14	326	6	8
	Number of non-circular dimples	324	324	324	0	320	330
	Ratio of circular dimples (%)	4	4	4	100	2	2

Land

Each

Total number

816

816

816

0

648

816

portion	land	Land portion pieces	Quantity	256	456	656	0	12	192
	portion	with all edge elements	Ratio (%)	31.4	55.9	80.4	—	1.9	23.5
	piece	having a curvature of
		not more than 0.40
		Land portion pieces	Quantity	250	450	650	0	0	18
		with all edge elements	Ratio (%)	30.6	55.1	79.7	—	0	2.2
		having a curvature of
		not more than 0.35

	Entire	Total number of curves	4,896	4,896	4,896	—	3,888	4,896
	ball	Total number of curves with	3,586	3,786	4,086	—	186	3,402
	surface	a curvature of not more than 0.40
		Ratio of curves with a curvature	73	77	83	—	5	69
		of not more than 0.40 (%)
Flight	W#1	Total (m)	272.6	273.4	274.0	270.4	271.0	272.2
	HS	Total compared with	2.2	3.0	3.6	0	0.6	1.8
	50 m/s	Comparative Example 1 (m)
		Rating	◯	◯	⊚	—	X	Δ
	W#1	Total (m)	234.8	235.4	235.6	232.1	232.8	234.1
	HS	Total compared with	2.7	3.3	3.5	0	0.7	2.0
	45 m/s	Comparative Example 1 (m)
		Rating	◯	⊚	⊚	—	X	Δ
	W#1	Total (m)	201.1	201.4	201.6	198.2	199.7	200.7
	HS	Total compared with	2.9	3.2	3.4	0	1.5	2.5
	40 m/s	Comparative Example 1 (m)
		Rating	◯	⊚	⊚	—	Δ	◯

Rating	W#1 HS 50 m/s total	3	3	5	0	0	1
(score)	W#1 HS 45 m/s total	3	5	5	0	0	1
	W#1 HS 40 m/s total	3	5	5	0	1	3
	Total	9	13	15	0	1	5
*The score is counted with “⊚” as 5 points, “◯” as 3 points, “Δ” as 1 point, and “X” as 0 points.

As shown in the results in Table 3, the golf balls of Comparative Examples 1 to 3 are inferior in the following respects to the golf balls according to the present invention (Examples).

Comparative Example 1 is a conventional golf ball composed only of circular dimples, and is significantly inferior in distance to the respective Examples under all conditions.

In Comparative Example 2, while the ball surface contains a unique land portion piece having a trifurcated shape in the land portion, the ratio of land portion pieces in which all the edge elements of the land portion are formed in a curve having a curvature of not more than 0.40 is very small. As a result, the distance under all conditions is significantly inferior to that in each Example.

In Comparative Example 3, while the ball surface contains a unique land portion piece having a trifurcated shape in the land portion, the ratio of land portion pieces in which all the edge elements of the land portion are formed in a curve having a curvature of not more than 0.40 or not more than 0.35 is small. As a result, the distance under conditions of HS 50 m/s and HS 45 m/s is significantly inferior to that in each Example.

Japanese Patent Application No. 2024-220845 is incorporated herein by reference. Although some preferred embodiments have been described, many modifications and variations may be made thereto in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims.