Description INSIDE STRUCTURE OF DIMPLE FOR GOLF BALL

Technical Field

[1] The present invention relates to a dimple structure of a golf ball, and more specifically to a dimple structure of a golf ball whereby the flying distance can be improved by modifying the lateral shape in the dimple of a golf ball. Background Art

[2] In the dimple structure of a conventional golf ball, various kinds are disclosed such as semi-spherical type, countersink type, pan type, and stepped protrusion type as shown in Figs. 1 to 4.

[3] For example, the golf ball having a pan type dimple structure flies with the golf ball rotating in the reverse direction of the advancing direction thereof, as shown in Fig. 5. In this case the air flow above the upper surface of the golf ball is faster than that below the lower surface by dint of the dimples. Therefore, it is a fact well known that the flying distance of the golf ball is improved because the lift of the golf ball is generated upward.

[4] It is also known that the pan type, rather than the semi-spherical type or countersink type, is advantageous in improving the lift, and the stepped type having a lateral protruded shape is most helpful in improving the lift, so dimples have been developed in this order.

[5] Such a development of the dimple could make the flying distance farther even if the number of the dimples in the golf ball was reduced from 500 to about 300, and also the material of the surface cover of the golf ball has been developed to the point of using a urethane material, which is a soft synthetic resin.

[6] But in such a conventional simple dimple structure, control of air flow is insignificant, so generation of the lift is very weak and improvement of the flying distance of the golf ball is limited. Disclosure of Invention

Technical Problem

[7] The present invention is to solve such conventional problems as described above with an object to provide a dimple structure of a golf ball whereby the flying distance of the golf ball is improved by increasing the lift during the flight of the golf ball and the air flow in the dimples can be properly controlled. Technical Solution

[8] In order to accomplish the above object of the present invention, there is provided a dimple structure of a golf ball characterized in that a plurality of concave dimples are

formed on the outer circumferential portion of the golf ball and at least one of the protruded portion and depressed portion is formed on the whole or part of said side section of the dimple. By the dimple structure of the present invention, the flying distance of the golf ball is improved by changing the air flow in the dimples of the golf ball. [9] Preferably, said protruded portion or depressed portion is formed monolithically on the side section along the circumference of said side section, and protrusions as the protruded portion or concaves as the depressed portion are formed on the side section at equal intervals along the circumference of the dimple. [10] Preferably, the width of said protruded portion or depressed portion in a slope direction is formed to be from 10 to 90% of the slope length of said side section of the dimple. [11] Preferably, the height of said protruded portion or the depth of said depressed portion is formed to be from 10 to 90% of said depth of the dimple. [12] Preferably, the sectional shape of said protruded portion or depressed portion is formed in at least one shape of circular and polygonal shapes such as triangular, rectangular and rhombic shapes. [13] Preferably, said protruded portion or depressed portion has a bend in an up or down direction of a slope formed between the top end and the bottom end of said side section of the dimple.

Advantageous Effects

[14] According to the present invention having such a configuration, the flying distance of the golf ball can be improved by forming the protruded portions or depressed portions on the side section of the dimple to improve the lift during the flight of the golf ball.

[15] Also, the protruded portion or depressed portion is formed monolithically on the side section along the circumference of the dimple and protrusions as the protruded portion and/or concaves as the depressed portion are formed on the side section at equal intervals along the circumference of the dimple, so air flow can be controlled much better.

[16] The protruded portion or the depressed portion is formed in a bend of an up or down direction on the slope between the top end and the bottom end of the side section, so up or down air flow in the dimple is controlled so as to increase the lift. Brief Description of the Drawings

[17] The above objects, features and advantages of the present invention will become more apparent to those skilled in the related art in conjunction with the accompanying drawings. In the drawings:

[18] Figs. 1 to 4 are sectional views showing the semi- spherical type, countersink type,

pan type and stepped protruded type dimple structures of a conventional golf ball, respectively; [19] Fig. 5 is a schematic view showing a flight state of a golf ball having the pan type dimple structure; [20] Fig. 6 is a partially cutaway view showing a dimple structure of a golf ball having a protruded portion according to one embodiment of the present invention; [21] Fig. 7 is a sectional view showing the dimple structure of a golf ball having the protruded portion according to one embodiment of the present invention; [22] Fig. 8 is a partially cutaway view showing a dimple structure of a golf ball having double protruded portions according to one embodiment of the present invention; [23] Fig. 9 is a sectional view showing the dimple structure of a golf ball having double protruded portions according to one embodiment of the present invention; [24] Fig. 10 is a partially cutaway view showing a dimple structure of a golf ball having double protruded portions of another shape according to the other embodiment of the present invention; [25] Fig. 11 is a sectional view showing the dimple structure of a golf ball having double protruded portions of another shape according to one embodiment of the present invention; [26] Fig. 12 is a partially cutaway view showing a dimple structure of a golf ball having multiple protruded portions according to one embodiment of the present invention; [27] Fig. 13 is a sectional view showing the dimple structure of a golf ball having multiple protruded portions according to one embodiment of the present invention; [28] Fig. 14 is a partially cutaway view showing a dimple structure of a golf ball having multiple complex protruded portions according to one embodiment of the present invention; [29] Fig. 15 is a sectional view showing the dimple structure of a golf ball having multiple complex protruded portions according to one embodiment of the present invention; [30] Fig. 16 is an enlarged sectional view of part "A" shown in Fig. 15.

[31] Fig. 17 is a sectional view showing a dimple structure of a conventional golf ball having a protruded portion; [32] Fig. 18 is a partially cutaway view showing a dimple structure of a golf ball having a protruded portion of another shape according to one embodiment of the present invention; [33] Fig. 19 is a sectional view showing the dimple structure of a golf ball having the protruded portion of another shape according to one embodiment of the present invention; [34] Fig. 20 is a perspective view showing a dimple structure of a golf ball having a protruded portion of another shape according to one embodiment of the present

invention; [35] Fig. 21 is a sectional view showing the dimple structure of a golf ball having the protruded portion of another shape according to one embodiment of the present invention; [36] Fig. 22 is a perspective view showing a dimple structure of a golf ball having rectangular protrusions as the protruded portion formed at equal intervals according to one embodiment of the present invention; [37] Fig. 23 is a sectional view showing the dimple structure of a golf ball having rectangular protrusions formed at equal intervals according to one embodiment of the present invention; [38] Fig. 24 is a perspective view showing a dimple structure of a golf ball having trapezoidal protrusions formed at equal intervals according to one embodiment of the present invention; [39] Fig. 25 is a sectional view showing the dimple structure of a golf ball having trapezoidal protrusions formed at equal intervals according to one embodiment of the present invention; [40] Fig. 26 is a perspective view showing a dimple structure of a golf ball having toothed protrusions formed at equal intervals according to one embodiment of the present invention; [41] Fig. 27 is a sectional view showing the dimple structure of a golf ball having toothed protrusions formed at equal intervals according to one embodiment of the present invention; [42] Figs. 28 to 30 are perspective views showing a variety of protrusions formed in the dimple structure of a golf ball according to one embodiment of the present invention; [43] Fig. 31 is a schematic view showing a flight state of a golf ball having a dimple structure according to one embodiment of the present invention; [44] Fig. 32 is a perspective view showing a dimple structure of a golf ball having circular protrusions formed at equal intervals according to one embodiment of the present invention; [45] Fig. 33 is a sectional view showing the dimple structure of a golf ball having circular protrusions formed at equal intervals according to one embodiment of the present invention; [46] Fig. 34 is a perspective view showing a dimple structure of a golf ball having rectangular protrusions formed at equal intervals according to one embodiment of the present invention; [47] Fig. 35 is a perspective view showing a dimple structure of a golf ball having circular rim protrusions according to one embodiment of the present invention; [48] Fig. 36 is a perspective view showing a dimple structure of a golf ball having

complex protrusions formed at intervals according to one embodiment of the present invention; [49] Fig. 37 is a sectional view showing the dimple structure of a golf ball having complex protrusions formed at intervals according to another embodiment of the present invention; [50] Fig. 38 is a partially cutaway view showing a dimple structure of a golf ball having a depressed portion according to another embodiment of the present invention; [51] Fig. 39 is a sectional view showing the dimple structure of a golf ball having the depressed portion according to another embodiment of the present invention; [52] Fig. 40 is an enlarged sectional view of part "B" shown in Fig. 39.

[53] Fig. 41 is a partially cutaway view showing a dimple structure of a golf ball having double depressed portions according to another embodiment of the present invention; [54] Fig. 42 is a sectional view showing the dimple structure of a golf ball having double- circular depressed portions according to another embodiment of the present invention; [55] Fig. 43 is a sectional view showing a dimple structure of a golf ball having continuous -circular depressed portions of another shape according to another embodiment of the present invention; [56] Fig. 44 is a partially cutaway view showing a dimple structure of a golf ball having double-rectangular depressed portions according to another embodiment of the present invention;

[57] Fig. 45 is a sectional view showing the dimple structure of a golf ball having double- rectangular depressed portions according to another embodiment of the present invention; [58] Fig. 46 is a partially cutaway view showing a dimple structure of a golf ball having double-triangle depressed portions according to another embodiment of the present invention;

[59] Fig. 47 is a sectional view showing the dimple structure of a golf ball having double- triangle depressed portions according to another embodiment of the present invention; [60] Fig. 48 is a perspective view showing a dimple structure of a golf ball having two trapezoidal concaves as the depressed portion formed at equal intervals according to another embodiment of the present invention; [61] Fig. 49 is a sectional view showing the dimple structure of a golf ball having two trapezoidal concaves formed at equal intervals according to another embodiment of the present invention; [62] Fig. 50 is a perspective view showing a dimple structure of a golf ball having a plurality of trapezoidal concaves formed at equal intervals according to another embodiment of the present invention; [63] Fig. 51 is a sectional view showing the dimple structure of a golf ball having the

plurality of trapezoidal concaves formed at equal intervals according to another embodiment of the present invention; [64] Figs. 52 to 56 are partial sectional views showing a variety of concaves formed in the dimple structure of a golf ball according to another embodiment of the present invention; [65] Fig. 57 is a perspective view showing a dimple structure of a golf ball having circular concaves formed at equal intervals according to another embodiment of the present invention; [66] Fig. 58 is a sectional view showing the dimple structure of a golf ball having circular concaves formed at equal intervals according to another embodiment of the present invention; [67] Fig. 59 is a perspective view showing a dimple structure of a golf ball having polygonal concaves formed at equal intervals according to another embodiment of the present invention; [68] Fig. 60 is a perspective view showing a dimple structure of a golf ball having circular rim concaves according to another embodiment of the present invention; [69] Fig. 61 is a perspective view showing a dimple structure of a golf ball having complex concaves formed at intervals according to another embodiment of the present invention; [70] Fig. 62 is a sectional view showing the dimple structure of a golf ball having complex concaves formed at intervals according to another embodiment of the present invention; [71] Fig. 63 is a perspective view showing a dimple structure of a golf ball having a plurality of protrusions and concaves formed alternately according to the other embodiment of the present invention; and [72] Fig. 64 is a sectional view showing the dimple structure of a golf ball having the plurality of protrusions and concaves formed alternately according to the other embodiment of the present invention.

Best Mode for Carrying Out the Invention [73] Hereinafter, dimple structure of a golf ball according to preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. [74] Fig. 6 is a partially cutaway view showing a dimple structure of a golf ball having a protruded portion according to one embodiment of the present invention, and Fig. 7 is a sectional view showing the dimple structure of a golf ball having the protruded portion according to one embodiment of the present invention. [75] Fig. 8 is a partially cutaway view showing a dimple structure of a golf ball having

double protruded portions according to one embodiment of the present invention, and Fig. 9 is a sectional view showing the dimple structure of a golf ball having double protruded portions according to one embodiment of the present invention.

[76] Fig. 10 is a partially cutaway view showing a dimple structure of a golf ball having double protruded portions of another shape according to the other embodiment of the present invention, and Fig. 11 is a sectional view showing the dimple structure of a golf ball having double protruded portions of another shape according to one embodiment of the present invention.

[77] Fig. 12 is a partially cutaway view showing a dimple structure of a golf ball having multiple protruded portions according to one embodiment of the present invention, and Fig. 13 is a sectional view showing the dimple structure of a golf ball having multiple protruded portions according to one embodiment of the present invention.

[78] Fig. 14 is a partially cutaway view showing a dimple structure of a golf ball having multiple complex protruded portions according to one embodiment of the present invention, Fig. 15 is a sectional view showing the dimple structure of a golf ball having multiple complex protruded portions according to one embodiment of the present invention, and Fig. 16 is an enlarged sectional view of part "A" shown in Fig. 15.

[79] Fig. 17 is a sectional view showing a dimple structure of a conventional golf ball having a protruded portion, Fig. 18 is a partially cutaway view showing a dimple structure of a golf ball having a protruded portion of another shape according to one embodiment of the present invention, and Fig. 19 is a sectional view showing the dimple structure of a golf ball having the protruded portion of another shape according to one embodiment of the present invention.

[80] Fig. 20 is a perspective view showing a dimple structure of a golf ball having a protruded portion of another shape according to one embodiment of the present invention, and Fig. 21 is a sectional view showing the dimple structure of a golf ball having the protruded portion of another shape according to one embodiment of the present invention.

[81] Fig. 22 is a perspective view showing a dimple structure of a golf ball having rectangular protrusions as the protruded portion formed at equal intervals according to one embodiment of the present invention, and Fig. 23 is a sectional view showing the dimple structure of a golf ball having rectangular protrusions formed at equal intervals according to one embodiment of the present invention.

[82] Fig. 24 is a perspective view showing a dimple structure of a golf ball having trapezoidal protrusions formed at equal intervals according to one embodiment of the present invention, and Fig. 25 is a sectional view showing the dimple structure of a golf ball having trapezoidal protrusions formed at equal intervals according to one embodiment of the present invention.

[83] Fig. 26 is a perspective view showing a dimple structure of a golf ball having toothed protrusions formed at equal intervals according to one embodiment of the present invention, and Fig. 27 is a sectional view showing the dimple structure of a golf ball having toothed protrusions formed at equal intervals according to one embodiment of the present invention.

[84] Figs. 28 to 30 are perspective views showing a variety of protrusions formed in the dimple structure of a golf ball according to one embodiment of the present invention, and Fig. 31 is a schematic view showing a flight state of a golf ball having a dimple structure according to one embodiment of the present invention.

[85] Fig. 32 is a perspective view showing a dimple structure of a golf ball having circular protrusions formed at equal intervals according to one embodiment of the present invention, and Fig. 33 is a sectional view showing the dimple structure of a golf ball having circular protrusions formed at equal intervals according to one embodiment of the present invention.

[86] Fig. 34 is a perspective view showing a dimple structure of a golf ball having rectangular protrusions formed at equal intervals according to one embodiment of the present invention, and Fig. 35 is a perspective view showing a dimple structure of a golf ball having circular rim protrusions according to one embodiment of the present invention.

[87] Fig. 36 is a perspective view showing a dimple structure of a golf ball having complex protrusions formed at intervals according to one embodiment of the present invention, and Fig. 37 is a sectional view showing the dimple structure of a golf ball having complex protrusions formed at intervals according to another embodiment of the present invention.

[88] As shown in Fig. 6 and Fig. 7, in the dimple structure of a golf ball according to the p resent embodiment, the golf ball has a plurality of concave dimples 10 formed on the outer circumference thereof. The dimple 10 has a protruded portion 20 formed mono- lithically in a rim shape on the whole or part of the side section 12 of the dimple 10.

[89] Namely, the dimple structure of the present embodiment is a type of structure that is not a stepped protruded type in the side section in dimple 10 of the golf ball, which was not possible to realize in the conventional dimple structure of a golf ball; it is a dimple structure of the golf ball having a different type of structure in which variation is given to the side section 12 of the dimple 10 so as to generate lift during the flight of the golf ball.

[90] Such a dimple structure of a golf ball can be represented by a case in which a block type protruded portion 20 is monolithically formed in a rim shape around the side section 12 like the present embodiment. By such a protruded portion 20, more air flows in the upper direction of the advance of the golf ball during the flight of the golf ball.

But in the lower direction of the advance of the golf ball, more air is controlled not to flow so as to improve lift, so the flying distance of the golf ball can be improved.

[91] In addition, the present embodiment can be said to be an effective embodiment that not only improves the lift of the golf ball like this but also makes the feel of ball hitting better. Especially in improving the feel of ball hitting, the head of a club does not touch the protruded portion 20 of the side section 12 during hitting so the feel of ball hitting, which is the hand feel of hitting, is improved by better transmission of force.

[92] As shown in Fig. 7, instead of the stepped type of the side surface that can be seen in a conventional golf ball, there is a structure in which a semi-circular band is mono- lithically formed on the side section; it is a configuration of another type for improving lift by increasing the curvature of the whole golf ball.

[93] In injection molding of the golf ball of the present embodiment, it can be thought there is difficulty due to the protruded portion at the time of formwork removal of the golf ball that has injection molding completed. But recently breakaway became possible owing to the development of soft synthetic resin that forms the cover of the golf ball. For example, by dint of a urethane cover and surlyn cover, problems with manufacture were solved, so there are no longer problems with the formwork removal.

[94] A common and ordinary depth of the dimple D is 0.15 to 0.24 mm, and each manufacturing company produces with its own characteristics for the depth of the dimple and the number of the dimples, so this embodiment description will be based on a depth of the dimple of 0.2 mm.

[95] When the depth of the dimple D is 0.2 mm, the width W of the dimple is determined to be 3 to 7 mm depending on whether the number of the dimples is large or small, but here description will be based on the case of the width of the dimple of 6 mm. As shown in Fig. 7, since the dimple slope length d is a little longer than the numerical value of the depth of the dimple D due to the slope, a relation D < d is formed.

[96] Therefore, defining the height h of the side section based on the depth of the dimple

D makes each slope length d much different even with the same depth in the countersink type with a small slope and the pan type with a large slope.

[97] Therefore, it is preferable to define the height h of the protruded portion of the side section based on the depth of the dimple D, and the width Wl of the protruded portion in the slope direction of the side section based on the slope length d of the dimple.

[98] Therefore, in the dimple structure, it is preferable to form the height h of the protruded portion of the side section at 10 to 90% of the depth of the dimple D. Specifically, the reason is because if the height h of the protruded portion is less than 10% of the depth of the dimple D, it is buried by coating liquid applied to the surface of the golf ball after an injection process of the golf ball, and if it is more than 90%, there will be difficulty in manufacturing the dimple.

[99] In defining the width of the protruded portion in the side section of the dimple 10, since one or more of the protruded portions can exist in the side section 12 of the dimple 10, it is preferable to form the whole width Wl of the protruded portion in the slope direction from 10 to 90% of the slope length d of the dimple.

[100] Specifically, the reason is because if the width Wl of the protruded portion in the slope direction is less than 10% of the slope length d of the dimple slope it can be buried with the surface coating liquid of the golf ball, and if it is larger than 90%, it becomes similar to the side section of the dimple, making it not easy to control air flow.

[101] As shown in Figs. 8 to 16, for the protruded portion of the present embodiment, a plurality of convex protruded portions can be formed variously such as a plurality of semi-circular protruded portions 21 and 23, a plurality of triangular protruded portions 22, a plurality of rectangular protruded portions 24 with a toothed part 24a formed on the top surface thereof, and a plurality of protruded portions 25 with a concave depression 25a formed on the top surface thereof.

[102] Such protruded portions are formed in plurality or in mixture so as to further control the flow of air during the flight of the golf ball. Accordingly, lift is improved during the flight of the golf ball and the flying distance can increase.

[103] Also, the protruded portions of various shapes that form convex circular rims on the side section of the dimple monolithically in the transverse direction, oblique direction and longitudinal direction are usually formed perpendicular to the dimple centerline or in such a way that they have lateral angles inclined outward.

[104] But in the present embodiment, soft urethane material or other synthetic resin is used for the material of the cover that envelops the inner core and mantle layer. And owing to the development of the formwork removal for removing golf balls from the die for the golf ball and the development of the technique of coating the die surface for the golf ball, the lateral structure of the dimple of the present embodiment may not have a lateral angle of the protruded portion perpendicular to the dimple centerline or inclined outward.

[105] Therefore, in the present embodiment, it is possible to give more lift to the golf ball by having a lateral angle of the protruded portion that is linearly perpendicular to the centerline of the dimple or inclined not outward but inward.

[106] As shown in Fig. 17, the conventional dimple structure has protruded portions 13 of various shapes that come in contact with the bottom section 11 on the side section 12 in the dimple 10 along the exterior angle line having an angle of inclination a with respect to the parallel line that is parallel to the centerline of the dimple 10.

[107] As shown in Fig. 18 and Fig. 19, in the present embodiment, the slope of the protruded portion 26 inclined at a predetermined interior angle b with respect to the

parallel line Cl that is parallel to the dimple centerline C is formed on the side section 12 of the dimple 10. In particular, it is more preferable to form the interior angle b at 2 to 5° so as to be suitable for the pulling out of the die for the golf ball during the injection process.

[108] Therefore, the protruded portion 26 of the side section of the dimple, which improves the lift of the golf ball by making air receive more resistance on the lower surface of the flying golf ball and flow more air on the upper surface, has interior angle slopes and is formed monolithically on the side section.

[109] As shown in Fig. 20 and Fig. 21, the bent- type protruded portion 20a according to the present embodiment has a bend in the up or down direction of a slope formed between the top end and the bottom end of the side section 12 of the dimple 10. Since it is possible to further control the flow of air during the flight of the golf ball by such a bent-type protruded portion 20a, the flying distance can be further increased by improving lift during the flight of the golf ball.

[110] As shown in Figs. 22 to 30 and Figs. 32 to 37, protrusions of various forms such as a rectangular, triangular, rim, etc., are formed on the side section 12 of a dimple 10 as the protruded portion of the present embodiment. The protrusions may also be formed of divided types or mixed types on the side section at equal intervals along the circumference of the dimple.

[I l l] It is also possible to divided the type of a plurality of protrusions in a shape of at least one of the vertical-type protrusions such as the rectangular protrusion 40a and the trapezoidal protrusion 40b that are formed by dividing the circumference of the dimple at equal intervals, the toothed protrusion 41, the circular protrusion 42, the rhombic protrusion 43, the complex protrusions 45 and 46 with the vertical type and horizontal type mixed, the oblique protrusion, and the polygonal protrusion.

[112] In addition, they exist as lateral supports of the dimple in a vertical-type, toothed- type, circular or polygonal structure existing on the side section of the dimple, and such lateral support portions of the vertical or horizontal semi-circular or polygonal dimple can be used simultaneously.

[113] As shown in Figs. 22 to 28, the protrusion as the protruded portion is of a shape of a vertical-type lateral protrusion, and the shapes of cross section also show various shapes of these, and Figs. 28 to 30 are perspective views of these. In particular, the protrusion of a laterally projecting stepped type of Fig. 28 is formed monolithically with the bottom section of the dimple at the bottom end and is united with the upper surface of the dimple at the upper end. But in Fig. 29 and Fig. 30, the protrusion comes down at a predetermined interval from the upper surface of the dimple and is also separated from the bottom section of the dimple in a protruded condition, and of course, this can be made as a unit simultaneously in the manufacturing process.

[114] As shown in Fig. 31 , in the golf ball having the dimple structure of the present embodiment, air T receives much resistance on the lower surface of the golf ball during the flight of the golf ball due to the shape of the protrusion that is various like described above, and more air T flows on the upper portion. Therefore, lift of the golf ball is improved, so the flying distance of the golf ball can be increased.

[115] Below will be described the dimple structure of a golf ball according to another embodiment of the present invention with reference to the accompanying drawings.

[116] Fig. 38 is a partially cutaway view showing a dimple structure of a golf ball having a depressed portion according to another embodiment of the present invention, Fig. 39 is a sectional view showing the dimple structure of a golf ball having the depressed portion according to another embodiment of the present invention, and Fig. 40 is an enlarged sectional view of part "B" shown in Fig. 39.

[117] Fig. 41 is a partially cutaway view showing a dimple structure of a golf ball having double depressed portions according to another embodiment of the present invention, Fig. 42 is a sectional view showing the dimple structure of a golf ball having double- circular depressed portions according to another embodiment of the present invention, and Fig. 43 is a sectional view showing a dimple structure of a golf ball having continuous -circular depressed portions of another shape according to another embodiment of the present invention.

[118] Fig. 44 is a partially cutaway view showing a dimple structure of a golf ball having double-rectangular depressed portions according to another embodiment of the present invention, and Fig. 45 is a sectional view showing the dimple structure of a golf ball having double-rectangular depressed portions according to another embodiment of the present invention.

[119] Fig. 46 is a partially cutaway view showing a dimple structure of a golf ball having double-triangle depressed portions according to another embodiment of the present invention, and Fig. 47 is a sectional view showing the dimple structure of a golf ball having double-triangle depressed portions according to another embodiment of the present invention.

[120] Fig. 48 is a perspective view showing a dimple structure of a golf ball having two trapezoidal concaves as the depressed portion formed at equal intervals according to another embodiment of the present invention, and Fig. 49 is a sectional view showing the dimple structure of a golf ball having two trapezoidal concaves formed at equal intervals according to another embodiment of the present invention.

[121] Fig. 50 is a perspective view showing a dimple structure of a golf ball having a plurality of trapezoidal concaves formed at equal intervals according to another embodiment of the present invention, and Fig. 51 is a sectional view showing the dimple structure of a golf ball having the plurality of trapezoidal concaves formed at

equal intervals according to another embodiment of the present invention.

[122] Figs. 52 to 56 are partial sectional views showing a variety of concaves formed in the dimple structure of a golf ball according to another embodiment of the present invention, Fig. 57 is a perspective view showing a dimple structure of a golf ball having circular concaves formed at equal intervals according to another embodiment of the present invention, and Fig. 58 is a sectional view showing the dimple structure of a golf ball having circular concaves formed at equal intervals according to another embodiment of the present invention.

[123] Fig. 59 is a perspective view showing a dimple structure of a golf ball having polygonal concaves formed at equal intervals according to another embodiment of the present invention, and Fig. 60 is a perspective view showing a dimple structure of a golf ball having circular rim concaves according to another embodiment of the present invention.

[124] Fig. 61 is a perspective view showing a dimple structure of a golf ball having complex concaves formed at intervals according to another embodiment of the present invention, and Fig. 62 is a sectional view showing the dimple structure of a golf ball having complex concaves formed at intervals according to another embodiment of the present invention.

[125] As shown in Fig. 38 and Fig. 40, in the dimple structure of a golf ball of the present embodiment, the golf ball has a plurality of concave dimples 10 formed on the outer circumferential portion thereof and a depressed portion 30 formed monolithically in a rim shape on the whole or part of the side section 12 of the dimple 10.

[126] Such a depressed portion 30 of the side section 12 can also improve the flying distance of the golf ball since it generates lift by controlling the flow of air during the flight of the golf ball like the protruded portion 20.

[127] In addition, it should be understood that the shape of the concave depressed portion, which is a shape opposite to the protruded portion of the side section of the dimple, is like the bend of the side section of the dimple, so it can help improve lift of the golf ball in the same fashion.

[128] Defining the depth dl of the depressed portion of the side section based on the depth of the dimple D causes much difference in each slope length d even at the same depth in the countersink type with a small slope and the pan type with a large slope.

[129] Therefore, it is preferable to define the length dl of the depressed portion of the side section based on the depth of the dimple D and the width W2 of the depressed portion in the slope direction of the side section based on the slope length d of the dimple.

[130] Therefore, in the dimple structure, it is preferable to form the length dl of the depressed portion of the side section from 10 to 90% of the dimple length D. Specifically, the reason is because if the depth dl of the depressed portion is less than

10% of the dimple length D, it is buried with the coating liquid to be coated on the surface after an injection process of the golf ball, and if it is larger than 90%, there is difficulty in manufacture of the dimple.

[131] In defining the width of the depressed portion in the side section of the dimple 10, since one or more of the depressed portions can exist in the side section 12 of the dimple 10, it is preferable to form the whole width W2 of the depressed portion in the slope direction from 10 to 90% of the slope length d of the dimple.

[132] Specifically, the reason is because if the width W2 of the depressed portion in the slope direction is less than 10% of the slope length d of the dimple, it can be buried with the surface coating liquid of the golf ball, and if it is larger than 90%, it becomes similar to the side section of the dimple, making it not easy to control air flow.

[133] In prior art it is understood that if the protruded portion in the dimple becomes larger, corrugations occur between the protruded portions, which become natural air lines, and if the air lines are made larger, the protruded portions are made on the inner sides of the dimples.

[134] But, in the process of forming circular, polygonal and toothed concaves on the side section of the dimple, which are different depression that is of a shape of a golf ball as between protruded portions existing on the side section of the dimple becomes larger, it is preferable that horizontal-type, vertical-type and single-shape depressions are formed on the side section of the dimple so that the golf ball can obtain as much lift as possible by dint of the rotary force of the golf ball that was hit and is flying.

[135] Fig. 40 shows the centerline Cl of the depressed portion 30 that is in parallel to the centerline C of the dimple 10, and the configuration of the depressed portion 30 of the side section 12 of the dimple 10 can have many boundary surfaces, and a triangular depressed portion can have a boundary line of a bottom end thereof and a boundary line of top end thereof.

[136] If there is a vertical line Cl of the depressed portion that is perpendicular to the bottom section 11 of the dimple and a horizontal line Pl of the depressed portion that is in parallel to the bottom section 11 of the dimple, the bottom end boundary line and the top end boundary line of the depressed portion are formed respectively on the horizontal line Cl and the vertical line Pl as follows.

[137] The horizontal bottom end boundary line of the depressed portion is formed between dimple side boundary surface and dimple bottom horizontal line Pl. Therefore, the bottom end boundary line has a predetermined angle of inclination g based on the horizontal line Pl.

[138] The top end boundary line has a predetermined angle of inclination q based on the vertical line Cl. Therefore, the top end boundary line can be formed monolithically within the lateral angle of inclination of the dimple in such a condition that it becomes

parallel to the horizontal line Pl of the dimple bottom.

[139] Especially, it is preferable to form the angle of inclination q of the top end boundary line from 2 to 5 so as to be suitable for the pulling out of the die for the golf ball during the injection process.

[140] And the concave depressed portion 30 also exists in a rim shape on the side section 12 of the dimple 10 of the golf ball and makes reverse rotation in the advance direction of the golf ball to make the flow of air above the golf ball flying with lift faster than the flow of air below the golf ball, so that it has an effect of controlling the air below.

[141] Therefore, likewise with the rim of the protruded portion, the depressed portion of rim shape shown in Fig. 38 and Fig. 39 has the same effect, so it is to be included as an identical invention.

[142] As shown in Figs. 41 to 47, the dimple structure of the present embodiment can have a plurality of depressed portions of concave shape, and can be formed variously in a plurality of semi-circular depressed portions 31 and 32, a plurality of rectangular depressed portions 33, and a plurality of triangular depressed portions 34.

[143] Such depressed portions are formed in plurality or in mixture to further control the flow of air to improve lift during the flight of the golf ball, so that the flying distance can be further increased.

[144] And there is prior art for the depression of the protruded rim whereby the rim on the whole of the dimple side is insertion-produced, but the rim of a depressed shape forms a depressed rim at predetermined intervals, so that generation of lift can be adjusted.

[145] In addition, by applying the height and width of the rim elastically to the protruded side rim, it is possible to adjust the size of the rim depending on a golfer's hitting style according to the swing speed and impact angle, for use by high-class, middle-class and beginner-class golfers.

[146] The depressed portion of the side section of the dimple may also be formed vertical to the bottom section of the dimple in a semi-circular shape, or polygonal shapes such as triangular, rectangular and rhombic shapes as a lateral depression of the dimple so as to it exist vertical to the dimple bottom in contrast to the explanation of the case of the depressed portion being in parallel to the dimple bottom section.

[147] As shown in Figs. 41 to 47, on the side of the golf ball rotating in the opposite direction of the advancing direction, the dimple cannot help but receive the resistance of air flowing sideways rather than the role of improving the direction of lift. Thus, the forming of depressions and protrusions vertical to the side section of the dimple can provide the golf ball another effect of improving the flying distance by reducing the above effect and the lateral resistance that can reduce the lift.

[148] As shown in Figs. 48 to 62, concaves of various forms such as a rectangular, triangular, rim, etc. are formed as the depressed portions of the present embodiment.

The concaves may also be formed of divided types or mixed types on the side section at equal intervals along the circumference of the dimple.

[149] In addition, the concave may also be formed in a divided shape of at least one of a separate horizontal concave at equal intervals along the circumference of the dimple, a vertical concave 51, circular concave 52, rhombic concave 53, circular rim type concave 54, complex concaves 55 and 56, in which both of the vertical type and horizontal type are alternately formed, and oblique type and polygonal type concaves.

[150] Therefore, likewise with the lateral protrusion of the dimple, the concave also can be used in a vertical, horizontal, single or parallel type. Likewise with the lateral protrusion of the dimple, it has also the effect whereby the lift during the flight of the golf ball is improved to further increase the flying distance.

[151] Below will be described the dimple structure of a golf ball according to another embodiment of the present invention with reference to the accompanying drawings.

[152] Fig. 63 is a perspective view showing a dimple structure of a golf ball having a plurality of protrusions and concaves formed alternately according to the other embodiment of the present invention, and Fig. 64 is a sectional view showing the dimple structure of a golf ball having the plurality of protrusions and concaves formed alternately according to the other embodiment of the present invention.

[153] As shown in Fig. 63 and Fig. 64, the dimple structure of the golf ball of the present embodiment is a mixed type structure in which both of the protrusion 61 as the protruded portion and the concave 62 as the depressed portion are alternately formed at equal intervals on the whole or part of the side section 12 of the dimple 10.

[154] The shapes and effects of the protrusion 61 and concave 62 of the present embodiment are the same as the above described embodiments. Industrial Applicability

[155] As described above, the dimple structure of a golf ball according to the present invention has the protruded portion and/or depressed portion formed on the side section of the dimple so as to increase lift during the flight of the golf ball, and the protrusion or concave is formed monolithically on the side section along the circumference of the dimple or is formed on the side section at equal intervals along the circumference of the dimple so as to control the flow of air, and the protruded portion or depressed portion is formed in a bend of an up or down direction of the slope between the top end and the bottom end of the side section so as to control the up or down air flow in the dimple to increase lift.

[156] Although the present invention has been described in connection with the exemplary embodiments illustrated in the drawings, it is only illustrative. It will be understood by those skilled in the art that various modifications and equivalents can be made to the

present invention. Therefore, the true technical scope of the present invention should be defined by the appended claims.