Golf Club Head Having Micro-vortex Generators

Abstract

A golf club head may comprise a hosel portion, a front strike face, a sole, a crown and micro-vortex generators projecting from a surface of the crown. The micro-vortex generators may comprise a first elongated micro-vortex generator angled with respect to the front strike face and a second elongated micro-vortex generator having a front end rearward of the first micro-vortex generator.

Description

BACKGROUND

[0001] During a swing of a golf club, whether it be a driver, a fairway wood or a hybrid club, air flows over the golf club head. This airflow separates from the golf club head, creating drag. Such drag reduces club head velocity during a swing which may lower the velocity of a golf ball being struck by the golf club head. As a result, the trajectory of the golf ball and the distance of the golf shot are reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] FIG. 1 is a fragmentary front view of an example golf club having an example golf club head with example schematically illustrated micro-vortex generators.

[0003] FIG. 2 is a top view of the example golf club head of FIG. 1 illustrating an example micro-vortex generation regions and example airflow across a golf club head during an example golf swing.

[0004] FIG. 3 is a heel side view of the example golf club head of FIG. 2 during the example golf swing.

[0005] FIG. 4 is a fragmentary front view of an example golf club head having example micro-vortex generators.

[0006] FIG. 5 is a fragmentary side view of the example golf club head of FIG. 4.

[0007] FIG. 6 is a fragmentary front view of an example golf club head having example micro-vortex generators.

[0008] FIG. 7 is a fragmentary side view of the example golf club head of FIG. 6.

[0009] FIG. 8 is a top view of an example golf club head having example micro-vortex generators.

[0010] FIG. 9 is a top view of an example golf club head having example micro-vortex generators.

[0011] FIG. 10 is a top view of an example golf club head having example micro-vortex generators.

[0012] FIG. 11 is a top perspective view of an example individual micro-vortex generator of the golf club head of FIG. 10.

[0013] FIG. 12 is a rear top perspective view of an example golf club head having example micro-vortex generators.

[0014] FIG. 13 is a sectional view of the example golf club head of FIG. 12.

[0015] FIGS. 14A-14F our time lapse views of a first example golf club head lacking micro-vortex generators and of a second example golf club head identical to the first example golf club head but for the addition of micro-vortex generators, the views illustrating airflow across a crown of each of the example golf club heads.

[0016] FIG. 15 is a diagram illustrating a wake area of aerodynamic drag during a swing of an example golf club head having a profile shown in broken lines in FIG. 13.

[0017] FIG. 16 is a diagram illustrating a wake area of aerodynamic drag during a swing of the example golf club head shown in FIG. 14 and lacking micro-vortex generators.

[0018] FIG. 17 is a diagram illustrating a wake area of aerodynamic drag during a swing of the example golf club head of FIGS. 12-14 including micro-vortex generators.

[0019] FIG. 18 is a diagram illustrating air streams during a swing of the example golf club head of FIG. 15 and having a profile shown in broken lines in FIG. 13.

[0020] FIG. 19 is a diagram illustrating air streams during a swing of the example golf club head shown in FIGS. 14 and 16 and lacking micro-vortex generators.

[0021] FIG. 20 is a diagram illustrating slow moving air streams during a swing of the example golf club head of FIGS. 12-14 and 17, the golf club head including micro-vortex generators.

SUMMARY

[0022] Described herein are various examples of golf club heads for use in golf clubs such as drivers, fairway woods and hybrid golf clubs. As will be described hereafter, the golf club heads comprise micro-vortex generators that delay separation of the airflow from the golf club head during a swing. As a result, drag is reduced. The reduced drag results in greater club head speed, greater golf ball velocity and longer drives.

[0023] In one implementation, a golf club head may comprise a hosel portion, a front strike face, a sole, a crown and micro-vortex generators projecting from a surface of the crown. The micro-vortex generators may comprise a first elongated micro-vortex generator angled with respect to the front strike face and a second elongated micro-vortex generator having a front end rearward of the first micro-vortex generator.

[0024] In one implementation, a golf club head may comprise a hosel portion, a front strike face, a sole, a crown and micro-vortex generators projecting from a surface of the crown. The micro-vortex generators may comprise elongated individual micro-vortex generators having a front end proximate the strike face, a rear and distant the strike face and an upper edge spaced no greater than 0.100 inches above the surface of the crown, the upper edge forwardly sloping downwards towards the surface of the crown.

DETAILED DESCRIPTION OF EXAMPLES

[0025] FIG. 1 illustrates an example golf club 10. The example golf club 10 of FIG. 1 is configured as a driver. Although the features of golf club 10 are illustrated with respect to a driver, the same features are also directly applicable to, fairway woods, hybrid clubs and combinations thereof in sets of golf clubs. The golf club 10 is an elongate implement configured for striking a golf ball and includes a golf shaft 12 having a butt end 13 with a grip 14 and a tip end 15 coupled to a club head 16.

[0026] The shaft 12 is an elongate hollow tube extending along a first longitudinal axis. The shaft 12 tapers toward the tip end 15. The shaft 12 is formed of a lightweight, strong, flexible material, preferably as a composite material. In alternative embodiments, the shaft 12 can be formed of other materials such as, other composite materials, steel, other alloys, wood, ceramic, thermoset polymers, thermoplastic polymers, and combinations thereof. The shaft can be formed as one single integral piece or as a multi-sectional golf shaft of two or more portions or sections.

[0027] As used herein, the term "composite material" refers to a plurality of fibers impregnated (or permeated throughout) with a resin. The fibers can be co-axially aligned in sheets or layers, braided or weaved in sheets or layers, and/or chopped and randomly dispersed in one or more layers. The composite material may be formed of a single layer or multiple layers comprising a matrix of fibers impregnated with resin. In particularly preferred embodiments, the number layers can range from 3 to 8. In multiple layer constructions, the fibers can be aligned in different directions with respect to the longitudinal axis 18, and/or in braids or weaves from layer to layer. The layers may be separated at least partially by one or more scrims or veils. When used, the scrim or veil will generally separate two adjacent layers and inhibit resin flow between layers during curing. Scrims or veils can also be used to reduce shear stress between layers of the composite material. The scrim or veils can be formed of glass, nylon or thermoplastic materials. In one particular embodiment, the scrim or veil can be used to enable sliding or independent movement between layers of the composite material. The fibers are formed of a high tensile strength material such as graphite. Alternatively, the fibers can be formed of other materials such as, for example, glass, carbon, boron, basalt, carrot, Kevlar.RTM., Spectra.RTM., poly-para-phenylene-2, 6-benzobisoxazole (PBO), hemp and combinations thereof. In one set of preferred embodiments, the resin is preferably a thermosetting resin such as epoxy or polyester resins. In other sets of preferred embodiments, the resin can be a thermoplastic resin. The composite material is typically wrapped about a mandrel and/or a comparable structure, and cured under heat and/or pressure. While curing, the resin is configured to flow and fully disperse and impregnate the matrix of fibers.

[0028] As further shown by FIGS. 1-3, golf club head 16 comprises a body 22 which additional components such as a sole plate or weights may be mounted. In the example illustrated, body 20 of the club head 16 can be formed as a single unitary, integral body through a combination of casting and welding. In another implementation, the club head 16 can be formed through a combination of forging and welding. In other implementations, the components of the body 20 of the club head 16 can be formed through casting, forging, welding, or a combination thereof. In one implementation, the body 20 of the club head 16 is made of a high tensile strength, durable material, preferably a stainless steel or titanium alloy. Alternatively, the body 20 of the club head 16 can be made of other materials, such as, for example, a composite material, aluminum, other steels, metals, alloys, wood, ceramics or combinations thereof.

[0029] The body 20 of the club head 16 comprises a generally vertical front striking plate or strike face 22, a sole 24, a crown 26, a hosel portion 28 and micro-vortex generators 30. The striking plate 22 extends from a heel portion 31 to a toe portion 32 of the club head 16. The sole 24 and the crown 26 rearwardly extend from lower and upper portions of the striking plate 22, respectively. The sole 24 generally curves upward to meet the generally downward curved crown 26. The portion of the sole 24 adjacent the crown 26 that connects the sole 24 to the crown 26 at perimeter locations other than at the striking plate 22 can be referred to as a side wall 34 or skirt.

[0030] The hosel portion 28 is a generally cylindrical body that upwardly extends from the crown 26 at the heel portion 31 of the club head 16 to couple the club head 16 to the shaft 12. The hosel portion 28 defines an upper hosel opening 36 for receiving the tip end of the shaft 12.

[0031] Micro-vortex generators 30 (schematically shown as blocks in FIGS. 1-3) comprise protrusions or projections rising up from the upper surface 38 of crown 26. The micro-vortex generators 30 are airflow boundary trip mechanisms. In one implementation, generators 30 are integrally formed as part of a single unitary body with crown 26. In another implementation, generators 30 are bonded, welded or otherwise fixed to the upper surface 38 of crown 26. In still other implementations, generators 30 may be removably fastened or mounted to surface 38 of crown 26.

[0032] Each of the individual micro-vortex generators projects from surface 28 so as to have a maximum height of no greater than 0.100 inch. In one implementation, the maximum height of each of micro-vortex generators is at least 0.025 inch and no greater than 0.100 inch. As shown by FIGS. 1 and 2, micro-vortex generators are distributed amongst at least two separate spaced micro-vortex generator regions 40A, 40B (collectively referred to as regions 40). Each of regions 40 comprises at least one individual micro-vortex generator 30.

[0033] As shown by FIG. 3, the at least one individual micro-vortex generator 30 (schematically shown) of region 40B, the rear region, has a front end 44 rearward of at least one individual micro-vortex generator 30 (schematically shown) of region 40A. In one implementation, each of regions 40 comprises multiple individual micro-vortex generators 30, wherein at least one of the micro-vortex generators 30 of the rear region 40B has a front end 44 rearward of and rearwardly spaced from at least one of the micro-vortex generators of region 40A. In the example illustrated, regions 40 each comprise a plurality of micro-vortex generators 30 arranged in a row extending parallel to the front strike face 22. As will be described with respect to other implementations, such as implementations shown in FIGS. 8-10, regions 40 may each comprise a plurality of micro-vortex generators 30 arranged in a curvilinear row having a concave side facing the rear of head 16. In yet another implementation, regions 40 may each comprise a plurality of micro-vortex generators 30 arranged in a pointed or multi-angled row.

[0034] As shown by FIG. 3, each individual micro-vortex generator 30 is an airflow boundary trip mechanism that impedes oncoming airflow during a golf swing such that the airflow must flow around the generator, forming a vortex 48 behind the individual generator 30. Such vortexes create turbulent flow adjacent surface 38, delaying the time at which the airflow separates from surface 38 and ultimately reducing the amount of drag experienced by head 16 during a golf swing. As shown by FIG. 3, the multiple generators 30 spaced from one another in a direction from front strike face 22 towards the rear 23 of head 16 create multiple vortices 48 that are also spaced from one another in a direction from front strike face 22 towards the rear 23 of head 16. As a result, airflow separates from surface 38 much closer to rear 23 as compared to a single region or row of generators 38. The micro-vortex generators 30 cause the separation point or separation line or separation curve of the airflow traveling over the crown 26 of the club head 16 to occur further rearward than a crown of a club head that has no micro-vortex generator 30. In other words, with the micro-vortex generators 30 the airflow stays closer to the crown of the club head for a greater distance or a greater amount of time, thereby reducing the aerodynamic drag of the air flowing over the club head.

[0035] As further illustrated by FIG. 2, the multiple regions 40 further create chaotic or tortuous airflow along surface 38 such that the airflow is redirected or changes directions multiple times. For example, airflow may be first directed or angled towards the heel and then redirected so as to be angled towards the toe of golf club head 16. In other words, the amount of linear air flow across surface 38 is reduced. This chaotic and tortuous airflow path along crown 26 creates turbulent flow and contributes to delaying separation of the airflow from surface 38, further reducing drag experienced by golf club head 16 during a golf swing.

[0036] It should be appreciated that although the two micro-vortex generators 30 illustrated in FIG. 3 are schematically illustrated with blocks or boxes, the individual micro-vortex generators 30 of each of regions 40 may have a variety of different shapes. In one implementation, micro-vortex generators 30 may have rectangular shapes. In another implementation, micro-vortex generators 30 may have rounded shapes. In still other implementations, micro-vortex generators 30 have varying height profiles front to rear, wherein each individual micro-vortex generator 30 has a lesser height proximate to strike face 22 and a greater height proximate to or towards rear 23. For example, in some implementations, micro-vortex generators 30 may be a triangular pyramid shape that tapers the slopes downward toward surface 38 as the triangular pyramid extends towards front strike face 22. In one implementations, the region or regions 40 may extend, or collectively extend, over at least 20 percent of the surface area of the crown 26 of the club head 16. In other implementations, the region or regions 40 may extend or collectively extend over other amounts of the surface area of the crown 26, such as at least 25 percent, at least 30 percent, at least 40 percent and at least 50 percent.

[0037] In some implementations, micro-vortex generators 30 are elongated and extend at different angles relative to strike face 22. In one implementation, micro-vortex generators 30 of the different regions 40 are transversely offset or staggered with respect to one another. For example, each of the micro-vortex generators 30 of region 40B may be offset either towards the heel or towards the toe of head 16 relative to the micro-vortex generators 30 of region 40A. The different angles or staggering of such vortex generators 30 further assists in generating chaotic or turbulent flow along surface 38 to further inhibit and delay separation or detachment of the airflow from surface 38, reducing drag.

[0038] FIGS. 4 and 5 illustrate golf club head 116, an example of golf club head 16. Golf club head 116 is similar to golf club head 16 except that golf club head 116 is specifically illustrated as comprising micro-vortex generators 130A, 130B, 130C, 130D (collectively referred to as generators 130), particular implementations of micro-vortex generators 30 which are schematically shown in FIGS. 1-3. As with micro-vortex generators 30, micro-vortex generators 130 project upwards from surface 38, having a maximum height of less than or equal to 0.100 inches. In the example illustrated, each of the individual micro-vortex generators 130 has an elliptical dome shape, forming an elliptical pimple rising above surface 38. In the example illustrated, each of the individual micro-vortex generators 130 has a sloping vertical profile, wherein the rearward most region of each generator 130 has a height above surface 38 that is greater than forward most regions of the generator 130.

[0039] As with head 16, the micro-vortex generators 130 of head 116 are arranged into groupings or regions 140A, 140B with region 140A being forward of region 140B. In the example illustrated, the front region 140A comprises generators 130A, 130B while rear region 140B comprises generators 130C and 130D. As shown by FIG. 4, generators 130C and 130D are both longitudinally (rearwardly) and transversely offset with respect to generators 130A and 130B.

[0040] FIGS. 6 and 7 illustrate golf club head 216, an example of golf club head 16. Golf club head 116 is similar to golf club head 16 except that golf club head 216 is specifically illustrated as comprising micro-vortex generators 230A, 130B and 230C (collectively referred to as generators 130), particular implementations of micro-vortex generators 30 which are schematically shown in FIGS. 1-3. As with micro-vortex generators 30, micro-vortex generators 230 project upwards from surface 38, having a height of less than or equal to 0.100 inch. In one implementation, the maximum height of each of micro-vortex generators is at least 0.025 inch and no greater than 0.100 inch. In the example illustrated, each of the individual micro-vortex generators 230 has a trapezoidal pyramid shape, having a base 232 facing in a rearward direction, a flat top 233 and tapering, sloping sides 234 extending forwardly from the rearwardly facing face on opposite sides of top 233. In the example illustrated, each of the individual micro-vortex generators 230 has a sloping or tapering overall profile, wherein the rearward most region of each generator 230 has a height above surface 38 that is greater than forward most regions of the generator 230.

[0041] As with head 116, the micro-vortex generators 230 of head 216 are arranged into groupings or regions 240A, 240B with region 240A being forward of region 240B. In the example illustrated, the front region 240A comprises generators 230A, 230B while rear region 240B comprises generator 230C. As shown by FIG. 6, generator 230C is both longitudinally (rearwardly) and transversely offset with respect to generators 230A and 230B.

[0042] FIGS. 8-10 are top views illustrating alternative layouts for the different regions of micro-vortex generators. FIG. 8 illustrates golf club head 316, another implementation of golf club head 16 having alternative layouts for regions 40 of micro-vortex generators 30. Golf club head 316 is similar to golf club head 16 described above except that golf club head 316 comprises micro-vortex generators 30 (schematically shown) arranged in curvilinear regions 340A and 340B (collectively referred to as regions 340). In each region 340, micro-vortex generators 30 are arranged in curvilinear row. Each of curvilinear regions 340 has a concave side facing rear 23 of golf club head 316. In the example illustrated, the curvilinear row of vortex generators 30 follows the airflow separation line, the general line at which the air flow begins to separate from surface 38, in the absence of the particular row of generators 30. As a result, the curvilinear row of vortex generators 30 may more effectively delay and move rearward the separation line which is characteristic of the golf club head geometry.

[0043] In one implementation, curvilinear regions 340 are nested with one another, having different radii. In other implementations, regions 340 may be sufficiently longitudinally offset from one another so as to not be nested within one another. The individual micro-vortex generators 30 have any of a variety of shapes similar to the shapes of generators 130 and 230 described above or shapes similar to any of the individual micro-vortex generators described hereafter. For example, the micro-vortex generators may have a hemi-spherical shape, an irregular shape, a cylindrical shape, a rectangular shape, other three dimensional polygonal shapes, other three dimensional curved shapes, and combinations thereof.

[0044] FIG. 9 illustrates golf club head 416, another implementation of golf club head 16 having alternative layouts for regions 40 of micro-vortex generators 30. Golf club head 416 is similar to golf club head 16 described above except that golf club head 416 comprises micro-vortex generators 430A, 430B and 430C (collectively referred to as generators 430) arranged in pointed or multi-angled regions 440A and 440B (collectively referred to as regions 440). In each region 440, micro-vortex generators 430 are arranged in pointed or multi-angled. Each of 440 has a concave side facing rear 23 of golf club head 316. In the example illustrated, the curvilinear row of vortex generators 30 generally follows the airflow separation line, the general line at which the air flow begins to separate from surface 38, in the absence of the particular row of generators 30. As a result, the curvilinear row of vortex generators 30 may more effectively delay and move rearward the separation line which is characteristic of the golf club head geometry.

[0045] In one implementation, curvilinear regions 440 are nested with one another, having different angles. In other implementations, regions 440 may be sufficiently longitudinally offset from one another so as to not be nested within one another. In the example illustrated, region 440A comprises multiple differently shaped are sized micro-vortex generators. In particular, at the point of region 440A, region 440A comprises micro-vortex generator 430B, a semi spherical generator, whereas the two wings of region 440A comprise micro-vortex generators 430A, rectangular generators. Region 430B comprises yet a third set of differently shaped generators, triangular pyramid. In other implementations, the particular shapes of the different micro-vortex generators in each of the different regions 440 may vary and may have other shapes based on the upon the particular geometries of head 16 on surface 38 to maximize turbulence and chaotic airflow to enhance the delay airflow separation and to enhance drag reduction.

[0046] FIG. 10 illustrates golf club head 516, another example implementation of golf club head 16. Golf club head 516 is similar to golf club head 16 except that golf club head 516 comprises micro-vortex generators 530 rising up from surface 38 of crown 26. In one implementation, the maximum height of each of micro-vortex generators is at least 0.025 inch and no greater than 0.100 inch. In contrast to micro-vortex generators 30 of head 16, micro-vortex generators 530 are generally arranged as a single grouping or cluster, without rows or columns. In one implementation, micro-vortex generators 530 have a generally random or non-ordered arrangement on surface 38. Each of micro-vortex generators 530 has a tapering vertical profile, wherein rearward most portions of each individual micro-vortex generator 530 have the greatest height above surface 38 while forward most portions of each individual micro-vortex generator 530 have the smallest height above surface 38.

[0047] FIG. 11 is an enlarged perspective view of an example individual micro-vortex generator 530. As shown by FIG. 11, generator 530 has a front race or face 532 and a pair of tapering side faces 534. The tapering profile as well as the sharp upper and forward corners or edges of generator 530 enhance airflow turbulence created by the individual micro-vortex generator 530. As with each of the individual micro-vortex generators described herein, micro-vortex generator 530 has a maximum height that is less than or equal to 0.100 inches. In one implementation, the maximum height of each of micro-vortex generators is at least 0.025 inch and no greater than 0.100 inch.

[0048] FIG. 12 is a rear perspective view of golf club head 616, another example implementation of golf club head 16. For ease of illustration, those components of golf club head 616 which correspond to components of golf club head 16 are numbered similarly. Golf club head 616 comprises micro-vortex generators 630A, 630B, 630C, 630D, 630E, 630F and 630G (collectively referred to as generators 630). Each of the individual generators 630 has a configuration similar to generator 530 illustrated in FIG. 11. In particular, each of generators 630 has a triangular pyramid shape having a largely vertical rear triangular face and forwardly extending triangular sides that extend to a point, the upper edge are ridge between the triangular sides forwardly tapering downward towards surface 28. As indicated above, the greater rearward height of each generator 630 and the sharp edges of each generator 630 enhance airflow turbulence. Each of the micro-vortex generators 630A thru G can be sized to extend over an area of the crown 26 of the club head 16 that is approximately 0.010 in.sup.2. In other embodiments, the size of each micro-vortex generator can be within the range of 0.005 in.sup.2 to 0.05 in.sup.2. In one implementations, a micro vortex generator region 660 defined by the area of the crown 26 that includes the micro-vortex generators 630 may extend over at least 20 percent of the surface area of the crown 26 of the club head 16. In other implementations, the region 660 may extend over other amounts of the surface area of the crown 26, such as at least 25 percent, at least 30 percent, at least 40 percent and at least 50 percent. The number and size of the micro-vortex generators 630 within the micro vortex generator region 660 defines a micro-vortex generator packing density. In one implementation, the micro-vortex generators 630 can be sized and/or numbered such that the generators 630 collectively extend over 2 percent to 50 percent of the surface area of the region 660 thereby forming a micro-vortex generator packing density within the range of 2 to 50 percent. In other implementations, the micro-vortex generator packing density within the range of 3 to 10 percent.

[0049] Micro-vortex generators 630 have a layout that enhances the delay of airflow separation from surface 38 to reduce drag. As shown by FIG. 12, generators 630A-630E, sometimes referred to as crown projections, are grouped are arranged in three regions or curvilinear rows 640A, 640B and 640C, each of the rows being nested within the other of the rows in each of the rows having a concave side facing rear 23 of crown 26. Row 630A extend closest to front strike face 22. Row 630A comprises generator 630A and generators 630B. Generator 630 extends parallel to, and in the example implementation contiguous with, a vertical plane 631 extending through head 16, perpendicular to a front center portion of front strike face 22. Plane 631 bifurcates golf club head 616 into a heel side 670 and a toe side 672.

[0050] Micro-vortex generators 630B extend on both sides of plane 631. Generators 630B extend in an arc forming row 640A. Generator 630 each point in a forward direction away from plane 631. Generators 630B are each angled with respect to plane 631, each individual generators 630 having a progressively greater angle with respect to the longitudinal vertical plane 631 as the individual micro-vortex generators become further transversely spaced from plane 631. In other words, generators 630B transversely closer to plane 631 have a smaller angle (closer to being parallel to plane 631) while generators 630B transversely farther away from plane 631 have a larger angle (closer to being perpendicular to plane 631). Those generators 630B on heel side 670 more aggressively and progressively point towards heel 31 as those generators 630B on heel side 670 become closer to heel 31. Likewise, those generators 630B on toe side 672 more aggressively and progressively point towards toe 32 as those generators 630B on toe side 672 become closer to toe 32. Such differential angling of generators 630A directs outer airflow, airflow towards the heel or toe of golf club head 616 back towards plane 631, towards the center and towards the apex of club 616 to increase airflow turbulence and reduce drag.

[0051] Micro-vortex generators 630C extend on both sides of plane 631. As with micro-vortex generators 630B, micro-vortex generators 630C are each angled with respect to plane 631. However, in complete contrast, individual generators 630C each point forwardly in a direction towards plane 631. In the example illustrated, generator 630C have a progressively smaller angle with respect to the longitudinal vertical plane 631 as the individual micro-vortex generators become further transversely spaced from plane 631. In other words, generators 630C transversely closer to plane 631 have a greater angle (closer to being perpendicular to plane 631) while generators 630C transversely farther away from plane 631 have a smaller angle (closer to being parallel to plane 631). Those generators 630C on heel side 670 more aggressively and progressively point away from heel 12 as those generators 630B on heel side 670 become closer to plane 631. Likewise, those generators 630B on toe side 672 more aggressively and progressively point away from toe 32 as those generators 630C on toe side 672 become closer to plane 631. Such differential angling of generators 630A breaks up and/or redirects airflow, changing its direction to increase airflow turbulence and reduce drag.

[0052] Micro-vortex generators 630D and 630E final row 640C. In the example illustrated, row 640C has the smallest radius of the three rows 640. Generator 630D is similar to generator 630A in that generator 630D is in substantial line with plane 631. Generators 630E are similarly angled as generators 630B. In the example illustrated, generators 630E are transversely (heel to toe) offset relative to generator 630B to further assist in generating turbulence across surface 38 of crown 26. In the example illustrated, each of generators 630B, 630D and 630E are aligned with radial lines extending from a single point rearward of row 640C and in plane 631. In other implementations, generators 630E may be in alignment with generators 630B.

[0053] In the example illustrated, generators 630A-630E partition crown 26 into three distinct regions: a front region that extends in front of the separation line of airflow (the line across crown 26 at which air begins to separate from head 616 absent projections given the geometry of head 16), a projection region including the projections and having a shape following or defined by the separation line and a rear region rearward of the projection region. The front region and the rear region lack projections. Generators 630A-E extend across the micro vortex generator region 660 (defined by a minimal shape containing each of generators 630A-630E) that covers from at least 20% up to 70% of the total surface area of crown 26. In the example illustrated, generators 630E extend rearward of the apex 651 of crown 26. As a result, generators 630A-630E assist in maintaining airflow adjacent to surface 38 of crown 26 for a longer period of time, prolonging or delaying the separation of such airflow to reduce drag.

[0054] The size of the micro vortex generator region 660 and the packing density of the micro-vortex generators adjusts and varies the ability of generators 630A-630E to create turbulent airflow with both vortices and transverse turbulent airflow across different areas or regions of crown 26 to reduce drag. In other implementations, although potentially less effective, micro-vortex generators 630A-630E may cover crown 26 to different extents or may have other arrangements over crown 26. For example, in some implementations, the crown generators 630 may be arranged in greater than or fewer than three curvilinear rows. The crown generators may alternatively be linear, extending parallel to front strike face 22 or may extend in rows that change directions at least once and even multiple times (as in a zigzag row) The crown generators may alternatively arranged in a non-uniform or unordered, dispersed fashion.

[0055] Micro-vortex generators 630F and 630G, sometimes referred to as hosel projections, extend proximate or adjacent to hosel 12. The hosel projections 630F and 630G extend across crown 26 generally from proximate front strike face 22 to proximate heel 31. Hosel projection 630 are distinct from the crown projections and do not extend across plane 631. Hosel projection 630 provides additional vortex generation proximate to heal 12 to address additional drag that may occur about hosel 12. In the example illustrated, generators 630G point towards hosel 12 while generators 630F have different angles, pointing away from hosel 12, more towards front strike face 22 and plane 631. Although hosel projection 630F and 630G are illustrated as comprising five individual micro-vortex generators, in other implementations, hosel projections 630F and 630G may have other densities or arrangements of generators in close proximity to hosel 12.

[0056] FIG. 13 is a sectional view of golf at club 616 along plane 631. As shown by FIG. 13, golf club head 616 is additionally shaped to further enhance the reduction of drag. In particular, the juncture 680 of front strike face 22 and crown 26 has an enlarged radius, enhancing the flow of air and reducing air separation.

[0057] As further shown by FIG. 13, the rear portions of crown 26 are more similar in height to the apex 651 of crown 26. In one implementation, rear portions are crown 26 extend at an angle A of less than or equal to 25 degrees from a generally horizontal plane. Likewise, the rear portions of sole 24 have a smaller angle with respect to the lowermost point of sole 24. The geometry of golf club head 616 further enhances the reduction in drag.

[0058] FIGS. 14A-14F illustrate the performance of micro-vortex generators 630 and their impact on airflow and drag. Each of such figures simulated airflow during a golf swing across to golf club heads 616 (described above) and 616'. The golf clubs including head 616 and 616' or identical in all respects but for the difference in the heads. The simulated swings and ambient environments of such two simulations are identical. Golf club heads 616 and 616' or identical in all respects but for the additional provision of micro-vortex generators 630 on crown 26.

[0059] As shown by the time-lapse progression of a golf swing (by robotic golf swing testing device) in FIGS. 14A-14D, micro-vortex generators 630 produced turbulent airflow which results in the airflow 650 closely following the contour of crown 26 of golf club head 616. This close conformance of the airflow 650 to the contour of crown 26 continues through the region of crown 26 including projections 630. Thereafter, as indicated in the FIGS. 14E-14F, the airflow 650 begins to separate from head 616. In contrast, with golf club head 616', lacking micro-vortex generators 630, the airflow 650' begins to immediately separate from the crown 26 as shown in FIG. 14A. The separation continues to grow as airflow 650' progresses rearwardly along crown 26. As shown by FIG. 14F, at the same identical point in time, the low pressure region following golf club head 616' is much larger than the low pressure region following golf club head 616. It is as low pressure region that creates drag. The greater the size and extent of the economic drag, the slower the velocity of the golf club head and the slower the velocity of the struck golf ball, reducing drive distance.

[0060] FIGS. 15-20 illustrate comparisons of the area of aerodynamic drag resulting in identical swings of golf clubs that are identical but for their differently configured heads. FIGS. 15 and 18 illustrate aerodynamic drag produced by the swing of a golf club head having a geometry shown in broken lines in FIG. 13 and lacking micro-vortex generators. FIGS. 16 and 19 illustrate aerodynamic drag produced by the swing of a golf club having golf club head 616' with the geometry shown in FIG. 13, but lacking micro-vortex generators. FIGS. 17 and 20 illustrate the area of aerodynamic drag produced by the swing of a golf club having golf club head 616 the from described above) which is identical to golf club head 616' but for the additional provision of the micro-vortex generators 630 described above.

[0061] As shown by a comparison of FIGS. 15 and 16, the more rounded or smoother juncture 680 and the more rounded crown 26 in sole 24 results in a reduction in drag. In the example illustrated, the changes in geometry resulted in a reduction in the area of aerodynamic drag from 6.23 in..sup.2 to 4.06 in..sup.2, a reduction in aerodynamic drag of at least 30% and approximating 35%. As shown by a comparison of FIGS. 18 and 19, the smoother geometry of golf club head 616' greatly reduces the wake area 684 of slower moving air that produces drag.

[0062] As shown by a comparison of FIGS. 16 and 17, the addition of micro-vortex generators 630 to the golf club head 616' further reduced aerodynamic drag by an additional 0.88 in..sup.2' to approximately 3.18 in..sup.2. The addition of micro-vortex generators 630 (shown in FIG. 12) reduced the area of aerodynamic drag by an additional 22%. As shown by a comparison of FIGS. 19 and 20, the additional micro-vortex generators 630 even further reduced the wake area 684 of slower moving air that produces drag. Although such benefits were obtained by adding micro-vortex generators 630 to club 616', it should be appreciated that similar benefits, greater or lesser in extent, may be likewise achieved by adding such micro-vortex generators 632 other clubs.

[0063] Although the present disclosure has been described with reference to example implementations, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the claimed subject matter. For example, although different example implementations may have been described as including one or more features providing one or more benefits, it is contemplated that the described features may be interchanged with one another or alternatively be combined with one another in the described example implementations or in other alternative implementations. Because the technology of the present disclosure is relatively complex, not all changes in the technology are foreseeable. The present disclosure described with reference to the example implementations and set forth in the following claims is manifestly intended to be as broad as possible. For example, unless specifically otherwise noted, the claims reciting a single particular element also encompass a plurality of such particular elements.

Claims

1. A golf club head comprising: a hosel portion; a front strike face; a sole; a crown; and micro-vortex generators projecting from a surface of the crown, the micro-vortex generators comprising: a first elongated micro-vortex generator angled with respect to the front strike face; and a second elongated micro-vortex generator having a front end rearward of the first micro-vortex generator, wherein the micro-vortex generators comprise: a first curvilinear row of micro-vortex generators, comprising the first elongated micro-vortex generator, having a first concave side facing a rear of the crown; and a second curvilinear row of micro-vortex generators, comprising the second elongated micro-vortex generator, having a second concave side facing the rear of the crown.

2. The golf club head of claim 1, wherein the first elongated micro-vortex generator extends at a first angle with respect to the front strike face and wherein second elongated micro-vortex generator extends at a second angle, different than the first angle, with respect to the front strike face.

3. The golf club head of claim 2, wherein the second elongated micro-vortex generator is to receive airflow from the first elongated micro-vortex generator and to redirect the received airflow.

4. (canceled)

5. The golf club head of claim 1 further comprising a third curvilinear row of micro-vortex generators having a third concave side facing the rear of the crown.

6. The golf club head of claim 5, wherein the first elongated micro-vortex generator extends parallel to a longitudinal vertical plane extending through the golf club head perpendicular to the front strike face and wherein each remaining elongated micro-vortex generator of the first curvilinear row of micro-vortex generators is rearwardly angled towards the longitudinal vertical plane.

7. The golf club head of claim 6, wherein the second curvilinear row of micro-vortex generators comprises individual micro-vortex generators rearwardly angled away from the longitudinal vertical plane.

8. The golf club head of claim 7, wherein the third curvilinear row of micro-vortex generators comprises individual micro-vortex generators transversely staggered with respect to individual micro-vortex generators of the first curvilinear row of micro-vortex generators.

9. The golf club head of claim 1, wherein each of the micro-vortex generators has a first end proximate the strike face that projects a first distance from the surface of the crown and a second end distant the strike face that projects a second distance, last than the first distance, from the surface of the crown.

10. The golf club head of claim 9, wherein each of the micro-vortex generators has a sharp upper edge.

11. The golf club head of claim 1, wherein the micro-vortex generators are contained within a projection region covering at least 20% and no greater than 70% of a total surface area of the crown.

12. The golf club head of claim 1, wherein the micro-vortex generators collectively have a surface area of at least 5% to no greater than 30% of a total surface area of the crown.

13. The golf club head of claim 12, wherein the collective surface area of the micro-vortex generators have a micro-vortex generator packing density within the range of 2 to 50 percent.

14. A golf club head comprising: a hosel portion; a front strike face; a sole; a crown; and micro-vortex generators projecting from a surface of the crown, the micro-vortex generators comprising: a first elongated micro-vortex generator angled with respect to the front strike face; and a second elongated micro-vortex generator having a front end rearward of the first micro-vortex generator, wherein the micro-vortex generators comprise a first curvilinear row of micro-vortex generators having a concave side facing a rear of the crown, wherein individual micro-vortex generators of the first curvilinear row have progressively greater angles with respect to a longitudinal vertical plane, extending through the golf club head perpendicular to the strike face, as the individual micro-vortex generators become further transversely spaced from the longitudinal vertical plane.

15. (canceled)

16. A golf club head comprising: a hosel portion; a front strike face; a sole; a crown; and micro-vortex generators projecting from a surface of the crown, the micro-vortex generators comprising: a first elongated micro-vortex generator angled with respect to the front strike face; and a second elongated micro-vortex generator having a front end rearward of the first micro-vortex generator, wherein the micro-vortex generators comprise: a first non-linear row of micro-vortex generators; and a second non-linear row of micro-vortex generators rearward the first non-linear row, wherein individual micro-vortex generators of the second non-linear row are transversely staggered with respect to individual micro-vortex generators of the first non-linear row.

17. The golf club head of claim 16, wherein the micro-vortex generators have an increased density proximate the hosel region.

18. (canceled)

19. The golf club head of claim 1, wherein each of the micro-vortex generators projects from the surface of the crown by less than 0.100 inches.

20. The golf club head of claim 1, wherein the micro-vortex generators comprising elongated individual micro-vortex generators having a front end proximate the strike face, a rear end distant the strike face and an upper edge spaced no greater than 0.100 inches above the surface of the crown, the upper edge forwardly sloping towards the surface of the crown.

21. The golf club head of claim 1, wherein the crown has an apex and wherein the micro-vortex generators are located rearward of the apex.

22. The golf club head of claim 1, wherein the micro-vortex generators decrease aerodynamic drag by at least 20%.

23. (canceled)

24. A golf club head comprising: a hosel portion; a front strike face; a sole; a crown; and micro-vortex generators projecting from a surface of the crown, the micro-vortex generators comprising: a first elongated micro-vortex generator angled with respect to the front strike face; and a second elongated micro-vortex generator having a front end rearward of the first micro-vortex generator, wherein the first elongated micro-vortex generator extends at a first angle with respect to the front strike face and wherein second elongated micro-vortex generator extends at a second angle, different than the first angle, with respect to the front strike face.

25. The golf club head of claim 24, wherein the second elongated micro-vortex generator is to receive airflow from the first elongated micro-vortex generator and to redirect the received airflow.