US20230372779A1

US20230372779A1 - Golf ball dimple constructed of radial channels

Info

Publication number: US20230372779A1
Application number: US17/747,248
Authority: US
Inventors: Michael R. Madson; David P. Hunt
Original assignee: Acushnet Co
Current assignee: Acushnet Co
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2023-11-23

Abstract

A golf ball includes a generally spherical surface and a plurality of dimples separated by a land area. At least one of the dimples has a perimeter edge connected to the land area and a dimple surface surrounded by the perimeter edge. The dimple surface includes a plurality of channels and a plurality of channel edges that extend continuously from the perimeter edge to an intersection at a dimple center. The dimple surface defines a dimple point depth in relation to continuation of the land area and a channel point depth in relation to the channel edges. Each channel includes a first area having a plan shape of a circular sector of a channel circle. The channel edges extend radially from the dimple center to a terminal end at the channel circle. The perimeter edge intersects the channel circle only at terminal ends of the plurality of channel edges.

Description

FIELD OF THE INVENTION

The present disclosure relates to golf balls, particularly to golf balls including dimples having ridged and/or textured surfaces. More particularly, the present disclosure relates to golf balls including dimples constructed of radial channels.

BACKGROUND OF THE INVENTION

Aerodynamic forces generated by a golf ball in flight are a result of its velocity and spin. These forces can be represented by a lift force and a drag force. Lift force is perpendicular to the direction of flight and is a result of air velocity differences above and below the rotating ball. This phenomenon is attributed to Magnus, who described it in 1853 after studying the aerodynamic forces on spinning spheres and cylinders, and is described by Bernoulli's Equation, a simplification of the first law of thermodynamics. Bernoulli's equation relates pressure and velocity where pressure is inversely proportional to the square of velocity. The velocity differential, due to faster moving air on top and slower moving air on the bottom created by the ball's spin, results in lower air pressure on top and an upward directed force on the ball.
Drag is opposite to the direction of flight and orthogonal to lift. The overall drag force on a ball is pressure drag and viscous or skin friction drag. A sphere is a bluff body, which is a somewhat inefficient aerodynamic shape. As a result, the accelerating flow field around the golf ball causes a large pressure differential with high-pressure forward and low-pressure behind the ball. The low-pressure area behind the ball is also known as the wake. In order to minimize pressure drag, dimples provide a means to energize the flow field and delay the separation of flow, or reduce the wake region behind the ball.
The industry has seen many efforts to improve the aerodynamic efficiency of golf balls, such as through variations in dimple configuration, dimple pattern, and other methods. For example, dimple properties such as number, shape, size, volume, edge angles and overall pattern have been manipulated in an attempt to generate a golf ball that has improved aerodynamic properties. A further consideration that may not be as thoroughly developed is the surface configuration and texture of the dimples themselves. Dimple surfaces can be adjusted and adapted to include non-smooth textures to introduce new air flow patterns and further refine the aerodynamic properties of the ball. The present disclosure relates to a development in surface texturing of a golf ball dimples to augment aerodynamic performance.

SUMMARY OF THE INVENTION

In one embodiment, the present disclosure describes a golf ball. The golf ball includes a generally spherical surface and a plurality of dimples separated by a land area formed on the surface. At least one of the dimples includes a perimeter edge connected to the land area and a dimple surface surrounded by the perimeter edge. The dimple surface defines a dimple point depth in relation to a phantom surface that is a continuation of the land area. The dimple surface includes a plurality of channels and a plurality of channel edges. At least one of (i) the plurality of channels or (ii) the plurality of channel edges extend continuously from the perimeter edge to an intersection at a dimple center. Each channel is defined by a portion of the dimple surface between a first edge of the plurality of channel edges and a second edge of the plurality of channel edges. The dimple surface further defines a channel point depth in relation to the first and second edges. Each channel includes a first area having a plan shape of a circular sector of a channel circle. The first and second edges are edges of the circular sector and extend radially from the dimple center to a terminal end at the channel circle. The perimeter edge intersects the channel circle only at terminal ends of the plurality of channel edges.
In another embodiment, the present disclosure describes another golf ball. The golf ball includes generally spherical surface and a plurality of dimples separated by a land area formed on the surface. At least one of the dimples comprises a perimeter edge connected to the land area and a dimple surface surrounded by the perimeter edge. The dimple surface defines a dimple point depth in relation to the land area and includes a plurality of channels radiating from a dimple center. The dimple surface further includes a plurality of channel edges separating the channels. The dimple point depth continuously increases from the perimeter edge to the dimple center along all radii of a dimple circle that circumscribes the perimeter edge.
In another embodiment, the present disclosure describes a method of manufacturing a golf ball. The method includes forming a golf ball having a generally spherical surface. The generally spherical surface includes a plurality of dimples separated by a land area formed on the surface. At least one of the dimples comprises a perimeter edge connected to the land area and a dimple surface surrounded by the perimeter edge. The dimple surface defines a dimple point depth in relation to the land area and includes a plurality of channels radiating from a dimple center. The dimple surface further includes a plurality of channel edges separating the channels. The dimple point depth continuously increases from the perimeter edge to the dimple center along all radii of a dimple circle that circumscribes the perimeter edge.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

FIG. 1 is a golf ball including a plurality of dimples, consistent with disclosed embodiments;

FIG. 2A is a plan view of a dimple having circular sector channels, consistent with disclosed embodiments;

FIG. 2B is a plan view of the two shaded circular sector channels shown in FIG. 2A;

FIG. 2C is a close-up view of detail AA from FIG. 2A;

FIG. 3 is a cross-sectional view of the dimple of FIG. 2A, taken along line B-B;

FIG. 4A is a cross-sectional view of dimple of FIG. 2A, taken along line C-C;

FIG. 4B is a close-up view of detail AB from FIG. 4A;

FIG. 5A is a cross-sectional view of dimple of FIG. 2A, taken along line D-D;

FIG. 5B is a close-up view of detail AC from FIG. 4A;

FIG. 6A is a cross-sectional view showing a circular half profile of a dimple, according to an embodiment;

FIG. 6B is a cross-sectional view showing a catenary half profile of a dimple, according to another embodiment;

FIG. 6C is a cross-sectional view showing a conical half profile of a dimple, according to yet another embodiment;

FIG. 7 is a plan view of another dimple having circular sector channels, consistent with another embodiment;

FIG. 8 is a plan view of another dimple having circular sector channels, consistent with another embodiment; and

FIG. 9 is a graphical representation of a relationship between dimple volume and plan shape area of non-spherical dimples according to some disclosed embodiments.

DETAILED DESCRIPTION OF THE INVENTION

The aerodynamic characteristics of a golf ball are largely dependent on the dimples present on the outer surface. Golf balls typically include 250-500 dimples on the outer surface that range from about 0.080-0.200 in. in diameter (or effective diameter, if non-circular). The arrangement of these dimples on the outer surface (i.e., the “dimple pattern”), the dimple shapes, the edge angles, the cross-sectional profiles, the depths, etc., all contribute to the overall flight performance of the golf ball. Dimple surface configuration and texture is another characteristic that affects the aerodynamic performance because the interaction between the dimple surface and the surrounding air affects the overall drag characteristics. For example, surface texture may be introduced to enhance aerodynamics
The present disclosure includes a golf ball including dimples having a ridged/textured surface. For example, in an embodiment, a disclosed dimple includes a plurality of radially-arranged channels connected around the dimple center. The channels may include at least a portion that is in the shape of a circular sector. For example, the channels may appear in a plan view as a pie chart with “pie slices” arranged around the center. The channels may additionally have a second portion that connects the circular sector to the surrounding land area of the golf ball. For example, the arc portion of the circular sector may be connected to a curved entrance zone that has an edge flush with the land area of the golf ball. Each radial channel may be connected to two adjacent radial channels at channel edges. The channel edges extend from the dimple center to the dimple perimeter edge. The channels and channel edges, which alternate in a circumferential direction (i.e., in a circle around the dimple center 20) around the dimple, make up an entirety of the surface of the dimple.
FIG. 1 is an illustration of a golf ball 10 according to an exemplary embodiment. The golf ball 10 includes a plurality of dimples 12. In the disclosed figures, the reference numerals are included and point to examples of corresponding components, even though more are shown. The description of one feature that is repeated can be equally applied to the same features throughout the embodiment. For example, in the depicted embodiment, all of the dimples shown on the golf ball 10 are the same or similar and thus are represented by the dimple 12. The dimples 12 are arranged on the spherical outer surface of the golf ball 10 in a dimple pattern. The dimples 12 are separated by a land area 14 of the spherical outer surface. The dimple pattern of the golf ball 10 is defined by the placement of the dimples 12 and land area 14, including the positioning of the dimples in relation to each other. The dimple pattern includes parameters such as dimple count, surface coverage, dimple spacing, pattern repetition, pattern symmetry, dimple orientation, dimple location, among other characteristics. A golf ball consistent with the present disclosure includes at least one dimple 12 having radial channels. In the depicted embodiment, all of the dimples 12 of the golf ball 10 incorporate surface texturing comprised of multiple radial channels connected around a center of the dimple. Other golf ball embodiments may include a combination of disclosed dimples 12 and other dimples, such as conventional spherical dimples with a smooth dimple surface.
FIG. 2A is a plan view of an exemplary one of the dimples 12. The dimple 12 includes a perimeter edge 16 demarking a dimple surface 17 of the dimple 12. The perimeter edge 16 is non-circular in the plan view. In an exemplary embodiment, the dimple surface 17 makes up an entirety of the dimple 12 within the perimeter edge 16. The dimple surface 17 includes a plurality of channels 18 radiating from a dimple center 20. The plan view in FIG. 2A is derived from a plane normal to an axis connecting the center of the golf ball 10 to the dimple center 20. The plurality of channels 18 are connected to each other by a plurality of channel edges 22. The plurality of channel edges 22 also radiate from the dimple center 20. The plurality of channels 18 and the plurality of channel edges 22 alternate in a circumferential direction, with the number of channels 18 equal to the number of channel edges 22. In an exemplary embodiment, the plurality of channel edges 22 each extend from the dimple center 20 to the perimeter edge 16. The channel edges 22 include terminal ends 24 that are connected to the perimeter edge 16.
In an exemplary embodiment, the perimeter edge 16 is non-circular and includes a scalloped edge shape that alternates between rounded peaks and pointed valleys in a plan view. The pointed valleys are connected to the terminal ends 24 of the channel edges 22. The scalloped edge shape of the perimeter edge accommodates an entrance zone into the plurality of channels 18 without an abrupt edge angle.
FIG. 2A shows three dotted-line circles near the perimeter edge 16. These circles are used to characterize features of the dimple 12 and are not physically present on the golf ball 10. In the depicted embodiment, a channel circle CC connects all of the terminal ends 24 of the channel edges 22. In FIG. 2A, the channel circle CC inscribes the perimeter edge 16, touching but not crossing the pointed valleys of the scalloped edge shape. As a result, the channel circle CC intersects the perimeter edge 16 only at the terminal ends 24 of the channel edges 22. In some embodiments, the channel circle CC is the largest circle having its center at the dimple center 20 that inscribes the perimeter edge 16 in the plan view of the dimple 12. In the depicted embodiment, a dimple circle DC connects all of the rounded peaks of the perimeter edge 16. The dimple circle DC circumscribes the perimeter edge 16, touching but not crossing the rounded peaks of the scalloped edge shape. In some embodiments, the dimple circle DC is the smallest circle having its center at the dimple center 20 that circumscribes the perimeter edge 16 in the plan view of the dimple 12. A mean circle MC is a circle having its center at the dimple center 20 and having a diameter that is an average of the diameters of the channel circle CC and the dimple circle DC. The diameter of the mean circle MC is equal to the sum of the diameter of the channel circle and the diameter of the dimple circle, divided by two. According to an exemplary embodiment, the diameter of the mean circle MC is considered the diameter D_Diaof the dimple 12.
The dimple center 20 may be a point at an intersection of the plurality of channels 18 and/or the plurality of channel edges 22. As will be described, the channel edges 22 approach the dimple surface 17 at the dimple center 20. In this way, it can be considered that at least one of (i) the plurality of channels 18 or (ii) the plurality of channel edges 22 extend continuously from the perimeter edge 16 to an intersection at the dimple center 20. For instance, the dimple center 20 may be considered a combination of channels 18 coming together at one point, a combination of the tops of channel edges 22 intersecting at one point, or both.
In another aspect, the dimple center 20 may be considered the point in the plan view that corresponds to the centroid of the dimple 12 (which may coincide with the center of the dimple circle DC). In FIG. 2A, the dimple center 20 is a point at the center of all of the channel circle CC, dimple circle DC, and mean circle MC. In some instances, the circles CC, DC, and MC are determined based on the dimple center 20. For example, the dimple center 20 may be determined based on the intersection of the channels 18 and/or channel edges 22, or the location of the dimple centroid and the circles CC, DC, and MC placed relative to that center. In other instances, the channel circle CC, dimple circle DC, and mean circle MC may be determined based on the perimeter edge 16 (e.g., by drawing circles that inscribe and circumscribe the perimeter edge 16) and the dimple center 20 determined based on the placement of one or more of these circles.
In FIG. 2A, the plurality of channels 18 include a first channel 26 and a second channel 28. FIG. 2B is an isolated plan view of channels 26 and 28. The plurality of channel edges 22 include a first channel edge 30, a second channel edge 32, and a third channel edge 34, also shown in FIG. 2B. The first channel 26 is adjacent to and connected to the second channel 28 by the first channel edge 30. The first channel edge 30 is thus a shared edge between the channels 26, 28. The second channel edge 32 is a boundary of the first channel 26, opposite from the first channel edge 30. Likewise, the third channel edge 34 is a boundary of the second channel 28, opposite from the first channel edge 30. The first channel edge 30 includes a terminal end 36. The second channel edge 32 includes a terminal end 38. The third channel edge 34 includes a terminal end 40. The terminal ends 36, 38, 40 are points at which the channel edges 30, 32, 34 intersect the perimeter edge 16. In addition, each of the terminal ends 36, 38, 40 are located on the channel circle CC. With respect to the channels 26, 28, the perimeter edge 16 intersects the channel circle CC only at the terminal ends 36, 38, 40. This is also true for the entire dimple 12 in which the perimeter edge 16 intersects the channel circle CC only at the terminal ends 24 of the channel edges 22. The channel circle CC in FIGS. 2A and 2B is shared by all of the channels 18, but it should be understood that in other embodiments each channel of a dimple may be associated with a different channel circle CC (and/or different dimple circle DC), such as in embodiments with different-size channels.
In the dimple 12, the channel circle CC divides each channel 18 into a first area 42 and a second area 44 (shown for example with respect to channels 26, 28 in FIG. 2B). The dimple surface 17 in the first area 42 has a shape of a circular sector of the channel circle CC in the plan view. A circular sector is a pie-shaped part of a circle consisting of an arc of the circle along with the two radii of the circle that connect to the ends of the arc. The first area 42 of the first channel 26 is bounded by the first channel edge 30, the second channel edge 32 and a segment 46 that connects the terminal ends 36 and 38. A central channel point 48 is near the midpoint of the segment 46. The central channel point 48 is a point on the dimple surface 17 that helps define a depth of the channels 18. The central channel point 48 may be at the midpoint of the segment 46, at the midpoint of a straight line connecting the terminal ends 36 and 38, or somewhere therebetween.
The dimple surface 17 in the second area 44 is situated between the perimeter edge 16 and the channel circle CC. The second area of the first channel 26 is bounded by the segment 46 of the channel circle CC and a portion 50 of the perimeter edge 16. The portion 50 has a rounded shape in the plan view and is one of the repeating curved segments that make up the scalloped edge shape of the perimeter edge 16. The portion 50 has peak 52. The peak 52 is the point on the perimeter edge 16 that touches the dimple channel DC. The peak 52 may be the midpoint of the portion 50. The channels 18 include a channel centerline CCL that connects the dimple center 20, the central channel point 48, and the peak 52 of the portion 50.
Each channel 18 includes a channel length CL. The channel length CL is measured from the dimple center 20 to the furthest point of the channel measured along the channel centerline CCL (e.g., the dimple center 20 to the peak 52 of the portion 50 of the perimeter edge 16). The channel length CL may also be characterized as a radius of the dimple circle DC. A radius of the channel circle R_CCis a length of the first area 42 of the channel 18 and is less than the channel length CL. Each channel also includes a channel width CW. The channel width CW is the largest width of the channel 18, which in the depicted embodiment is measured as a straight-line distance between the terminal ends 24 of the channel edges 22. The channels 18 also include an angle of separation AS. The angle of separation AS is measured as the angle between the channel centerlines CCL. In the embodiment of FIG. 2A, the dimple 12 includes 26 equally-spaced channels 18 and channel edges 22 such that the angle of separation AS is π/13 or approximately 13.85°.
FIG. 2C is a close-up view of the detail AA of FIG. 2A, further illustrating one of the channels 18, including the dimple surface 17 in the first area 42 and the second area 44. The channel circle CC is shown connecting the terminal ends 24 of the channel edges 22 by the segment 46. The dimple surface 17 in the first area 42 slopes both from the channel edges 22 toward the channel centerline CCL and from the channel circle CC toward the dimple center 20. The depth of a point on the dimple surface 17 may be measured in the first area 42 in relation to a continuation of the land area 14. The dimple surface 17 in the second area 44 slopes from the perimeter edge 16 toward the central channel point 48. In the second area 44, an entrance depth may be measured in relation to the land area 14. The entrance depth increases radially from the perimeter edge 16 toward the central channel point 48. The dimple surface 17 in the first area 42 includes a groove profile between the channel edges 22, as will be further described. The dimple surface 17 in the second area 44 includes a spherical profile, similar to a conventional dimple, to transition smoothly from the land area 14 to the groove profile of the channel 18.
FIG. 3 is a cross-sectional view of the dimple 12, taken at line B-B of FIG. 2A. FIG. 3 illustrates the groove profile of the channels 18 and further shows the channel width CW between the terminal ends 24. In an exemplary embodiment, the channel 18 has circular shaped profile having a channel radius of curvature R_Ch. The channel radius R_Ch, according to disclosed embodiments, may be between approximately 0.01 in. and 0.13 in. In other embodiments, different cross-sectional shapes (e.g., other U-shapes, V-shapes, sinusoidal shapes, stepped shapes, etc.) are also possible. In the embodiment of the dimple 12, the groove profile of the channels 18 are all be the same. In other embodiments, different channels may have different profiles.
The channel 18 has a channel depth DC that is calculated as the distance between the channel edge 22 and the central channel point 48 on the dimple surface 17. The channel depth DC may differ slightly from that shown in FIG. 3 , because the central channel point 48 may not lie perfectly on the cutting plane of the cross-section of FIG. 3 . In an exemplary embodiment, the channel depth DC is a maximum depth in comparison to depth measurements at other points within the channel 18. Channel depth at any given point within the channel 18 may be referred to herein as a channel point depth CPD. The channel depth DC measured at the central channel point 48 is a maximum channel point depth CPD of the channel 18.
The channel depth DC is a channel parameter, indicating how deep the channel is at a point spaced from the center of the dimple. However, the channel point depth CPD, in general, may be measured at any point within a channel 18 and compared to the channel edge 22. The channel point depth CPD measurement may use a cross-section at the same radial points on the two channel edges 22 that delimit the channel being measured (such as in FIG. 3 ). In another example, the channel point depth CPD measurement may be taken at the same radial position (i.e., distance from the dimple center 20). In measuring channel point depth CPD, the channel edges 22 may be defined to always have a channel point depth CPD of zero. The channel point depth CPD may then be measured as the displacement from a point on the channel surface to the channel edge 22 using the cross-sectional or same-radial-position method. For the purpose of this disclosure, channel point depth CPD measurements refer to depths of points relative to channel edges 22 in a cross-section through the same radial points on the channel edges 22.
FIG. 4A is a cross-sectional view of the dimple 12, taken at line C-C of FIG. 2A. FIG. 4A illustrates a dimple half profile, as taken through the channel centerline CCL of two opposing channels 18. In FIG. 4A, a ball phantom surface 54 is shown above the dimple 12 as a continuation of the land area 14 of the golf ball 10. FIG. 4A shows how the dimple surface 17 descends below the land area 14 around the perimeter edge 16 and continues below the phantom surface 54 toward the dimple center 20. The channel edge 22 that can be seen in FIG. 4A also descends below the phantom surface 54 continuously toward the dimple center 20. The dimple depth D_Dis measured from the phantom surface 54 to the dimple center 20. Dimple point depth DPD, in general, may be measured at any point on the dimple surface 17 with respect to the land area 14 and/or phantom surface 54 by taking a cross-section at any radius of the dimple circle DC and measuring a displacement from the selected point on the dimple surface 17 to the land area 14 or phantom surface 54. In the first area 42 of the channels 18, the dimple point depth DPD may be a measure between the dimple surface 17 and the phantom surface 54. In at least some embodiments, the dimple point depth DPD is greatest at the dimple center 20 (i.e., the dimple depth D_Dis the maximum dimple point depth DPD of the dimple 12). In the second area 44 of the channels 18, the dimple point depth DPD may be described as an entrance depth between the dimple surface 17 and the land area 14. The entrance depth increases radially from the perimeter edge 16 toward the central channel point 48.
FIG. 4B is a close-up view of the detail AB of FIG. 4A, further illustrating the variation in dimple point depth DPD and channel point depth CPD along a channel centerline CCL. FIG. 4B shows the channel depth D_Cnear the terminal end 24 of the channel edge 22. As has been discussed, the channel depth D_Cis considered as the largest channel point depth CPD of the channel 18. For other points along the channel 18, the channel point depth CPD (shown in solid lines) along the channel centerline CCL continuously decreases from the channel circle CC toward the dimple center 20. Conversely, the dimple point depth CPD along the channel centerline CCL (shown in dotted lines), including the entrance depth within the second area 42, continuously increases from the dimple circle D_Ctoward the dimple center 20.
The channel depth D_Cmay be compared to the dimple depth D_Din another dimple parameter. For example, a ratio between the channel depth D_Cand the dimple depth D_Dmay further characterize the slope of the dimple surface 17 within the circular sector portions of the channels 18. In an exemplary embodiment, the channel depth D_Cat the channel circle CC is approximately 1-20% of the dimple depth D_Dat the dimple center 20.
FIG. 5A is a cross-sectional view of the dimple 12, taken at line D-D of FIG. 2A. FIG. 5A illustrates another dimple half profile, as taken through the channel edges 22 of two opposing channels 18. FIG. 5B is a close-up view of the detail AC of FIG. 5A.
As mentioned above with respect to FIGS. 4A-4B, the channel point depth CPD of a channel 18 continuously decreases toward the dimple center 20. This is true for at least all radii that are on the channel centerlines CCL, but not for radii that are on the channel edges 22. FIGS. 5A-5B, being a cross-section taken on radii that are on channel edges 22, do not show a channel point depth CPD, because the channel point depth CPD is zero on the channel edge 22. Thus, the channel point depth CPD is constant on radii of the channel circle CC that are on the channel edges 22. Conversely, FIGS. 5A-5B further shows how the dimple point depth DPD (shown in dotted lines) continuously increases toward the dimple center 20 even on radii that are on the channel edges 22. Indeed, in an exemplary embodiment, the dimple point depth DPD continuously increases toward the dimple center 20 along all radii of the channel circle CC and dimple circle DC, culminating in the dimple depth D_Dat the dimple center 20.
The disclosed embodiments include dimples having radial channels that have a portion that is a circular sector in a plan view. The channels include channel point depths CPD that approach zero at a dimple center and a dimple point depth DPD that approaches a maximum (i.e., the dimple depth D_D) at the dimple center. The dimple surface that accommodates these characteristics may take different shapes and configurations and embodiments. The dimples 12 and channels 18 of the above embodiments have a half profile (also referred to herein as dimple profile) that follows a circular arc.
FIG. 6A illustrates another cross-sectional view of a dimple 56 having radial channels 58 and channel edges 60. The dimple 56 also has a circular arc profile across a diameter. The circular arc profile of the dimple 56 is slightly more curved that the circular arc profile of the dimple 12, resulting in a dimple having a greater depth and/or edge angle. The channel edges 60 of the dimple 56 also follow a circular arc profile. FIG. 6B illustrates a cross-sectional view of a dimple 62 having channels 64 and channel edges 66. In FIG. 6B, the half profile of the dimple 62 follows a path of a catenary curve. The channel edges 66 also follow a catenary curve and meet a dimple center, similar to the dimple 12. FIG. 6C illustrates a cross-sectional view of a dimple 68 having channels 70 and channel edges 72. The half profile of the dimple 68 includes converging linear paths, creating a conical dimple. The channel edges 72 also follow linear paths, further adding to the conical shape of the dimple 68. The dimples 56, 62, and 68 include different dimple profiles but have the same dimple depth D_Dand dimple diameter D_Diaof the mean circle MC.
While the depicted examples include matches between the half profile shape of the channel surfaces and the channel edges, it should be understood that other embodiments may combine different profiles. For example, some embodiments may include a channel surface curved in a half profile according to a circular arc, combined with channel edges having a catenary or linear half profile. Other combinations are also possible.
The disclosed embodiments include radial channels and channel edges that alternate in a circumferential direction around the dimple center, making up an entirety of a dimple surface interior to a perimeter edge. As described herein, the radial channels make up an entirety of the dimple surface. As a result, the number of radial channels equals the number of channel edges. Disclosed embodiments may include more or less channels than those depicted. For example, it is contemplated that disclosed embodiments may include between 10 and 50 channels. According to some embodiments, a disclosed dimple may include at least ten channels and ten channel edges. In other embodiments, a disclosed dimple may include at least twenty channels and twenty channel edges. Another embodiment of a disclosed dimple includes fifty channels and fifty channel edges.
In some embodiments, the channels and channel edges may be positioned such that the angle of separation AS is equal for each channel, such as in the dimple 12. This produces an axial symmetric configuration about the dimple center, with axial symmetry in number equal to the number of channels and number of channel edges. For example, the dimple 12 has 26-fold axial symmetry with 26 equal channels 18 and channel edges 22. In other embodiments, a dimple may have channels of different channel widths CW and angles of separation AS. These dimples may or may not have axial symmetry around the dimple center. For example, some dimples may have axial symmetry in number less than he number of channels and channel edges.
FIG. 7 is a plan view of a dimple 74 having a plurality of channels 76 and a plurality of channel edges 78. The dimple 74 has sixteen channels 76 of varying channel widths CW and angles of separation AS. The dimple 74 follows the same parameters with respect to a channel circle CC and dimple circle D_Cas the dimple 12. Unlike the dimple 12, the dimple 74 has axial symmetry in number less than the number of channels 76 and channel edges 78. In particular, the dimple 74 is arranged with 2-fold axial symmetry about the dimple center.
FIG. 8 is a plan view of a dimple 80 having a plurality of channels 82 and a plurality of channel edges 84. The dimple 80 has eleven channels 82 of varying widths CW and angles of separation AS. The dimple 80 follows the same parameters with respect to a channel circle CC and dimple circle D_Cas the dimple 12. Unlike the dimples 12 and 74, the dimple 80 does not have axial symmetry about the dimple center.
Dimples of the present disclosure, which are generally non-spherical in comparison to conventional dimples, may have a plan shape area and dimple volume within a range having a lower limit and an upper limit selected from the values within the region shown in FIG. 9 .
The plan shape area is based on a planar view of the dimple plan shape, such that the viewing plane is normal to an axis connecting the center of the ball to the point of the calculated surface depth. The dimple volume is the total volume encompassed by the dimple shape and the surface of the golf ball. The preferred dimple volume will be less than the upper limit volume calculated by
V _s=−0.0464x ²+0.0135x−2.00×10⁻⁵
and greater than the lower limit calculated by
V _s=−0.0300x ²+0.0016x−3.00×10⁻⁶
where x is the dimple plan shape area and x is between 0.0025 and 0.045 inclusive.
For purposes of the present disclosure, the plan shape area of a non-spherical dimple is based on a planar view of the dimple plan shape, such that the viewing plane is normal to an axis connecting the center of the ball to the point of the calculated surface depth.
An example of a dimple according to disclosed embodiments is further described below. The dimple may have a general appearance of the dimple 12 as shown in FIGS. 1-5B. The exemplary dimple includes 26 channels and 26 channel edges, producing a constant angle of separation AS of approximately 13.85°. Additional dimensions of the example dimple are shown in the table below.

TABLE 1

Example Channel Dimensions

	Channel Width, CW (inches)	0.022
	Channel Length, CL (inches)	0.098
	Channel Depth, D_C(inches)	0.002
	Channel Radius, R_Ch(inches)	0.031
	Dimple Depth, D_D(inches)	0.013
	Dimple Diameter D_Dia(inches)	0.188

These dimensions are exemplary and may be changed or altered to accommodate different aerodynamic performance of a golf ball. For example, one or more dimensions may be tuned such that the textured/ridged dimples enhance the aerodynamic performance of the golf ball. In another example, the dimensions may be tuned to limit the capabilities of the golf ball and thereby produce a reduced distance golf ball.
Golf balls consistent with the disclosure include at least one disclosed dimple having radial channels. Some golf balls may include a plurality of golf dimples, where all of the dimples have radial channels as disclosed. Other embodiments of golf balls may include a plurality of dimples, with at least one of the dimples being different than the disclosed dimples having radial channels. For example, a golf ball may include a combination of conventional smooth-surface spherical dimples and disclosed dimples having radial channels. The combination of dimples may be arranged in a dimple pattern to produce a desired aerodynamic performance of the golf ball.
Disclosed embodiments may further include methods of manufacturing golf balls having disclosed dimples constructed of radial channels. The disclosed methods may include compression molding, injection molding, or other golf ball manufacturing methods. Golf balls manufactured to include the disclosed dimples on the generally spherical surface may have any golf ball construction known in the art, such as one or more core layers, a casing layer, and a cover layer. The disclosed dimples may be included in the cover layer, which may be covered by one or more paint and/or coating layers.
When numerical lower limits and numerical upper limits are set forth herein, it is contemplated that any combination of these values may be used. All numerical values and ranges set forth herein are approximate.
All patents, publications, test procedures, and other references cited herein, including priority documents, are fully incorporated by reference to the extent such disclosure is not inconsistent with this invention and for all jurisdictions in which such incorporation is permitted.
While the illustrative embodiments of the invention have been described with particularity, it will be understood that various other modifications will be apparent to and can be readily made by those of ordinary skill in the art without departing from the spirit and scope of the invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and descriptions set forth herein, but rather that the claims be construed as encompassing all of the features of patentable novelty which reside in the present invention, including all features which would be treated as equivalents thereof by those of ordinary skill in the art to which the invention pertains.

Claims

What is claimed is:

1. A golf ball, comprising:

a generally spherical surface; and

a plurality of dimples separated by a land area formed on the surface, wherein at least one of the dimples comprises:

a perimeter edge connected to the land area; and

a dimple surface surrounded by the perimeter edge and defining a dimple point depth in relation to a phantom surface that is a continuation of the land area, the dimple surface comprising a plurality of channels and a plurality of channel edges, wherein at least one of (i) the plurality of channels or (ii) the plurality of channel edges extend continuously from the perimeter edge to an intersection at a dimple center,

wherein each channel comprises a portion of the dimple surface between a first edge of the plurality of channel edges and a second edge of the plurality of channel edges, wherein the dimple surface defines a channel point depth relative to the first and second edges,

wherein each channel comprises a first area having a plan shape of a circular sector of a channel circle,

wherein the first and second edges are edges of the circular sector and extend radially from the dimple center to a terminal end at the channel circle, and

wherein the perimeter edge intersects the channel circle only at terminal ends of the plurality of channel edges.

2. The golf ball of claim 1, wherein the dimple point depth continuously increases toward the dimple center along all radii of the channel circle.

3. The golf ball of claim 2, wherein the channel point depth continuously decreases toward the dimple center along all radii of the channel circle that are centerlines of the plurality of channels.

4. The golf ball of claim 1, wherein the perimeter edge is non-circular in a plan view of the at least one dimple.

5. The golf ball of claim 4, wherein the perimeter edge comprises a scalloped edge shape in a plan view of the at least one dimple.

6. The golf ball of claim 1, wherein each channel further comprises a second area between the perimeter edge and the channel circle.

7. The golf ball of claim 6, wherein the portion of the perimeter edge in the second area comprises a rounded shape in a plan view.

8. The golf ball of claim 6, wherein the dimple surface in the second area defines an entrance depth in relation to the land area, and wherein the entrance depth increases radially from the perimeter edge toward a central channel point.

9. The golf ball of claim 8, wherein the central channel point is near a midpoint between the terminal ends of the first and second edges on the channel circle.

10. The golf ball of claim 1, wherein the dimple surface comprises at least ten channels and at least ten channel edges.

11. The golf ball of claim 10, wherein the dimple surface comprises at least twenty channels and at least twenty channel edges.

12. The golf ball of claim 1, wherein each channel further comprises a circular arc profile having a channel radius between approximately 0.01 in. and 0.13 in.

13. The golf ball of claim 1, wherein the channel point depth at the channel circle is approximately 1-20% of the dimple point depth at the dimple center.

14. The golf ball of claim 1, wherein the plurality of channels and the plurality of channel edges are axially symmetric about the dimple center.

15. The golf ball of claim 1, wherein the plurality of channels and the plurality of channel edges are not axially symmetric about the dimple center.

16. The golf ball of claim 1, wherein the at least one of the dimples further comprises a dimple profile comprising a circular arc.

17. The golf ball of claim 1, wherein the at least one of the dimples further comprises a dimple profile comprising a catenary curve.

18. The golf ball of claim 1, wherein the at least one of the dimples further comprises a dimple profile comprising converging linear paths.

19. A golf ball, comprising:

a generally spherical surface;

a perimeter edge connected to the land area; and

a dimple surface surrounded by the perimeter edge and defining a dimple point depth in relation to the land area, the dimple surface comprising a plurality of channels radiating from a dimple center and a plurality of channel edges separating the channels,

wherein the dimple point depth continuously increases from the perimeter edge to the dimple center along all radii of a dimple circle that circumscribes the perimeter edge.

20. A method of manufacturing a golf ball, comprising forming a generally spherical surface, the generally spherical surface comprising:

a perimeter edge connected to the land area; and