Golf club head with improved sole

A golf club head with an improved sole profile is disclosed herein. More specifically, the present invention discloses a wedge type golf club head wherein the sole is formed from continuously variable radius of curvature from the leading edge to the trailing edge, without any identifiable inflection points. The resulting golf club head improves performance, as this new sole profile allows specific portions of the sole to have a profile that meets the needs at that location.

FIELD OF THE INVENTION

The present invention relates to a golf club head having an improved sole profile. More specifically, the present invention relates to an iron type golf club head with an improved sole profile, as the iron type golf club head of this type often has significant sole contact, and can benefit from improvements in the sole profile. The sole profile becomes more important in wedge type golf club heads used for shorter shots, as not only do they need to engage the sole in full swing shots, but must also be versatile enough to perform in various different types of wedge shots.

BACKGROUND OF THE INVENTION

Iron type golf clubs are generally used by golfers to hit golf shots from the turf, which means they are designed to hit golf shots that lay directly on the grass itself. Given that the sole of these types of golf club heads are the part of the golf club head that has the most surface area to contact the turf, the design of the sole profile often has a significant impact on the quality of the turf interaction.

U.S. Pat. No. 945,944 to Dalgleish illustrates one of the earlier attempts at improving the performance of the golf club by changing the sole profile. Despite the fact that the invention by Dalgleish was directed more of a “brassies” type wood or fiber golf club head, it illustrated an early recognition of the importance of sole interaction with a golf club and a design intended to improve the performance.

In a more modern context, U.S. Pat. No. 4,671,513 to Swanson illustrates “a golf club iron provided with protuberances or knobs on the bottom sole face thereof to minimize ‘fat’ shots, reduce the size of the divots, and to accommodate tilting of the club head on the turf laterally and in front to rear directions without spoiling the shot.”

U.S. Pat. No. 7,393,286 to Renegar provides an alternative way to adjust the sole of a golf club by providing contours to help the interaction between the golf club and the turf it often comes in contact with.

Finally, U.S. Pat. No. 6,471,601 to McCabe et al. provides another illustration wherein the sole of the golf club head is improved for better performance, this time utilizing a crescent surface, a positive bounce surface, a heel surface, and a toe surface.

The present invention improves upon the previously mentioned designs by creating a golf club head wherein the sole contours are carefully designed to improve the performance of the golf club head not only improving full shots; as shown by all the previous examples, but also improving other types of shots. More specifically, the present invention recognizes that a wedge type golf club head may be used to execute a multitude of different golf shots, including but not limited to full shots, flop shots, knock down shots; all of which engage different portions of the sole contour.

BRIEF SUMMARY OF THE INVENTION

One aspect of the present invention is a golf club head comprising of a striking face located at a frontal portion the golf club head, a topline located at an upper portion of the golf club head, a heel portion located at a proximal end of the golf club head, adapted to receive a shaft, a toe portion located at a distal end of the golf club head opposite the heel end, and a sole located at a lower portion of the golf club head opposite the topline. The sole further comprises of a leading edge point and a sole trailing contact point, wherein the sole further comprises of two or more convex radii that are different from each other, and wherein the sole has a sole entry height of between about 2.0 mm and about 8.0 mm, the sole entry height is defined as a difference between a height of the sole at the leading edge point and a height of the sole at a distance of 1.2 mm back from the leading edge point.

Another aspect of the present invention is a golf club head comprising of a striking face located at a frontal portion the golf club head, a topline located at an upper portion of the golf club head, a heel portion located at a proximal end of the golf club head, adapted to receive a shaft, a toe portion located at a distal end of the golf club head opposite the heel end, and a sole located at a lower portion of the golf club head opposite the topline. The sole further comprises of a leading edge point and a sole trailing contact point, wherein said sole further comprises two or more convex radii that are different from each other, and wherein the sole has a sole entry angle of greater than about 60°; the sole entry angle defined as an angle created by a line connecting the leading edge point and a height of the sole at a distance 1.2 mm back from the leading edge point, relative to a horizontal plane.

A further aspect of the present invention is a golf club head comprising of a striking face located at a frontal portion the golf club head, a topline located at an upper portion of the golf club head, a heel portion located at a proximal end of the golf club head, adapted to receive a shaft, a toe portion located at a distal end of the golf club head opposite the heel end, and a sole located at a lower portion of the golf club head opposite the topline. The sole further comprises of a leading edge point and a sole trailing contact point, wherein said sole further comprises two or more convex radii that are different from each other, and wherein the golf club head has a “Sole Contour Ratio” of less than about 0.25, the “Sole Contour Ratio” is defined as a leading edge sole radius divided by a trailing edge sole radius.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1of the accompanying drawings shows a perspective view of a golf club head100in accordance with an exemplary embodiment of the present invention. The golf club head100shown inFIG. 1may generally have a sole102, a topline104, a toe portion106, a heel portion108, and a hosel110. Although not visually discernable from this perspective view, the golf club head100shown inFIG. 1incorporates a new and innovative sole profile that dramatically improves the performance of the golf club head100. The innovative sole102contains a continuously variable radius of curvature from the leading edge to the trailing edge of the sole102without any identifiable inflection points. This continuously variable radius allows for a more exact adjustment of the specific sole102to accommodate the specific needs of the sole102at various different points to help improve the performance of the golf club head100.

FIG. 2of the accompanying drawings shows a toe side view of a golf club head200in accordance with an exemplary embodiment of the present invention. The toe side view of the golf club head200allows two key features to be shown in more detail. More specifically,FIG. 2of the accompanying drawings shows a leading edge220, which is defined in the current application as the most forward point of the golf club head220, with the hosel210in an upright 90 degree position from a ground plane224. This leading edge220is then defined as the forward most point along the z-axis, as indicated by the axis of origin201. In addition to illustrating the leading edge220,FIG. 2of the accompanying drawings shows a sole trailing contact point222, which is defined as the lowest point and most rearward point of the golf club head200, again with the hosel210in a 90 degree position from the ground plane224. The sole trailing contact point222is then defined as the lowest point along a y-axis, referring back to the origin201. The sole trailing contact point222may be used to create cross-sectional line A-A′, which will be used to create different cross-sectional views of the golf club head200in subsequent figures to illustrate the innovative sole profile. Using the leading edge220and the sole contact point222, the sole width d1of the golf club head220can be defined. The sole width d1, of a golf club head200in accordance with the current embodiment may vary depending on the loft and bounce of the golf club head200, but may generally be between about 5 mm to about 22 mm, more preferably between about 10 mm to about 22 mm, and most preferably between about 15 mm to about 22 mm without departing from the scope and content of the present invention.

It should be noted here that in this current exemplary embodiment of the present invention, the leading edge220occurs at a specific point along the x-y-plane and the sole trailing contact point222is generally defined along the x-axis. This leading edge220along the x-axis, may generally occur at the “center of the golf club head200”, which is defined as the center point of the scorelines instead of the actual geometric center of the golf club head200along the x-axis. In order to better illustrate the definition of the “center of the golf club head200” used in the current disclosure,FIG. 3is provided showing a golf club head300from a frontal view.

FIG. 3of the accompanying drawings shows a frontal view of a golf club head300in accordance with an exemplary embodiment of the present invention. In the frontal view of the golf club head300shown inFIG. 3, previously mentioned golf club head300components such as the sole302, topline304, toe portion306, heel portion308, and the hosel310still remain. In addition to the previously mentioned components,FIG. 3shows the striking face312located at a frontal portion of the golf club head300adapted for striking a golf ball. The striking face312may further be comprised out of a plurality of scorelines314, which helps control the spin of a golf ball that comes in contact with the striking face312of the golf club head300. The scorelines314shown inFIG. 3, may serve to help define “center of the golf club head300” for the current application. More specifically, “center of the golf club head300”, as defined by the current disclosure, refers to the center point of the lowest scoreline314along the x-axis shown by origin301. The location of the “center of the golf club head300” along the x-axis can then serve to help define cross-sectional line B-B′, which includes leading edge320and sole trailing contact point322. Further detail can be shown regarding the innovative sole302profile in accordance with the present invention can be shown inFIG. 4, which provides a cross-sectional view of the golf club head300taken along cross-sectional line B-B′.

FIG. 4of the accompanying drawings shows a cross-sectional view of a golf club head400taken along cross-sectional line B-B′ shown inFIG. 3. This cross-sectional view of the golf club head400allows a better illustration of the innovative sole402in accordance with the present invention. First and foremost, it is worth noting here thatFIG. 4of the accompanying drawings is based off an embodiment of the golf club head400that has a high bounce sole402profile. High bounce sole402may generally have a higher bounce angle θ, defined as the angle created between the leading edge point420and the sole trailing contact point422. The bounce angle θ in this embodiment of the present invention may generally be greater than about 20°. In addition to showing the bounce angle,FIG. 4of the accompanying drawings also shows a sole width d1of the current golf club head400as being between about 15 mm and about 22 mm, more preferably between about 10 mm and about 22 mm, and most preferably between about 15 mm and about 22 mm. The sole width d1in this embodiment is defined as the distance along the z-axis measured from the leading edge point420and the sole trailing contact point422.

In addition to illustrating the bounce angle θ of the golf club head400,FIG. 4of the accompanying drawing also shows a leading edge sole radius ρ1located near the leading edge point420as well training edge sole radius ρ2located at the sole trailing contact point422. The leading edge sole radius ρ1in this invention may generally be defined at the radius of curvature of the sole402for an initial distance of d2of exactly 1.2 mm rearward of the leading edge point420, while the trailing edge sole radius ρ2may generally be defined as the radius of the curvature of the sole402for a terminal distance d2of exactly 1.2 mm forward of the sole trailing contact point422. Unlike some prior art golf clubs that creates a sole using a convex sole followed by a concave sole, the present invention utilizes a continuous convex sole geometry from the leading edge point420until the sole trailing contact point422. Alternatively speaking, it can be said that both the leading edge sole radius ρ1and the trailing edge sole radius ρ2are both convex in shape. The continuously variable sole402in this embodiment of the present invention may generally begin with a leading edge sole radius ρ1of less than about 10 mm and finish with a trailing edge sole radius ρ2of greater than about 40 mm, more preferably begin with a leading edge sole radius ρ1of less than about 9 mm and finish with a trailing edge sole radius ρ2of greater than about 41 mm, and most preferably begin with a leading edge sole radius ρ1of less than about 8 mm and finish with a trailing edge sole radius ρ2of greater than about 42 mm.

Due to the dramatic difference between the leading edge sole radius ρ1and the trailing edge sole radius ρ2, it can be said that a golf club head400in accordance with the present invention may have a rounder sole profile near the leading edge point420, while at the same time having a flatter sole profile near the sole trailing contact point422. Alternatively speaking, the golf club head400in accordance with an exemplary embodiment of the present invention may generally have a “Sole Contour Ratio” of less than about 0.25, more preferably less than about 0.21, and most preferably less than about 0.19. The “Sole Contour Ratio” is defined by Equation (1) below:

FIG. 4of the accompanying drawings also illustrates another characteristic of the current innovative sole402of having a large amount of area contained below the bounce bifurcation line424, especially when compared to a traditional wedge type golf club head. The bounce bifurcation line424, as shown in this current embodiment of the present invention, as shown here inFIG. 4is defined as the line that connects the leading edge point420and the sole trailing contact point422, and helps create the sole camber area426. Because the area below the sole bifurcation line424becomes larger as the bounce angle θ of the sole402increase, in the current high bounce version of the golf club head400, the sole camber area426may generally be greater than about 42 mm2, more preferably greater than about 45 mm2, and most preferably greater than about 48 mm2.

Due to the fact that the sole camber area426is a function of the bounce angle θ, another interesting relationship could be created to quantify the unique sole402contour of the current golf club head400. More specifically, it can be said that a sole402profile in accordance with a present invention may have a “Camber to Bounce Area Ratio” of greater than about 2.00 mm2/°, more preferably greater than about 2.50 mm2/°, and most preferably greater than about 3.00 mm2/° all without departing from the scope and content of the present invention. The “Camber to Bounce Area Ratio”, as it can be seen fromFIG. 4is a way to quantify the meatiness of the sole402as it relates to a specific bounce angle θ, and can be defined by Equation (2) below:

Finally,FIG. 4of the accompanying drawings shows a circular region A covering the leading edge point420as well as the leading edge sole radius ρ1, allowing more details of that very important portion of the golf club head400to be shown in more detail inFIG. 5.

FIG. 5of the accompanying drawings shows an enlarged cross-sectional view of the leading edge point520as well as the leading edge sole radius ρ1shown as circular region A inFIG. 4. This enlarged view of the golf club head allows the focus of the discussion to shift to the leading edge point520, which is critical to the proper function of the current inventive sole502of the present invention. As previous discussion has already addressed, the new innovative continuously variable sole derives its benefit from creating a new innovative sole502profile; and the leading edge point520helps define the start of this innovative sole502profile. In order to quantify this unique innovative sole502profile near the leading edge point520, an offset distance d2has already been discussed above inFIG. 4as being exactly 1.2 mm away from the leading edge point520. This offset distance d2helps create a leading edge sole profile, beginning with the leading edge point520and ending with a leading edge trailing point521. Although the leading edge sole radius ρ1has already discussed in prior discussion regardingFIG. 4, the enlarged cross-sectional view shown here allows two additional variables to be illustrated. The two key additional variable shown here is the leading edge sole entry height d3, and the leading edge sole entry angle Φ, both are critical in providing more detail regarding the innovative sole502of the golf club head.

The sole entry height d3shown inFIG. 5illustrates the amount of sole thickness formed in an initial portion of the sole502of the golf club head. This initial portion is defined as d2, which has already been previously defined as a distance of exactly 1.2 mm rearward from the leading edge point520. In order to determine the sole entry height d3, the height difference between the leading edge point and the sole thickness at the leading edge trailing point521along the y-axis identified by origin501. In this current exemplary embodiment of the present invention, the sole entry height d3may generally be between about 2.0 mm and about 8.0 mm, more preferably between about 2.5 mm and about 8.0 mm, and most preferably between about 3.0 mm and about 8.0 mm. Alternatively speaking, it can be said that the sole entry height d3is defined as a difference between a height of the sole502at said leading edge point520and a height of said sole at a distance d2of 1.2 mm back from the leading edge point520. In order to create this inventive sole profile, the sole entry height d3may generally be paired with a sole entry angle Φ of greater than about 60°, more preferably greater than about 65°, and most preferably greater than about 67.5°. This sole entry angle Φ may generally be defined as the angle created by the line created by the leading edge point520and the leading edge trailing point521, relative to a horizontal plane.

FIG. 6of the accompanying drawings shows a cross-sectional views of different golf club heads600(a),600(b), and600(c) in accordance with different embodiments of the present invention that have a high bounce angle θ(a), mid bounce θ(b), and low bounce θ(c) soles respectively. Visually, it can be seen from the combined view of the three cross-sectional views here that different bounce angles may yield different leading edge point620(a),620(b), and620(c) that correspond with different sole trailing contact points622(a),622(b), and622(c) respectively. Needless to say, the different bounce angles will yield different leading edge sole radius ρ1(a), ρ1(b), and ρ1(c) as well as different trailing edge sole radius ρ2(a), ρ2(b), and ρ2(c). Although the discussion above providing the range of data is applicable irrespective of the bounce angle θ, specific numbers will be provided below in Table 1, illustrating the trend of the changes in these key features in their specific embodiments.

Before moving onto Table 1,FIG. 7of the accompanying drawings that provide enlarged views of the leading edge portion of the sole of golf club heads in accordance with different embodiments of the present invention having different bounce angles. More specifically,FIG. 7shows sole entry angle Φ(a), Φ(b), and Φ(c) pairing with a high bounce, mid bounce, and a low bounce sole respectively. Finally,FIG. 7also shows leading edge sole entry height d3(a), d3(b), and d3(c), also pairing with high bounce, mid bounce, and low bounce soles respectively.

In addition to providing an innovative sole profile in a front to back orientation that is continuously variable, the innovative sole is also continuously variable in a heel to toe orientation. In order to illustrate this continuously variable sole profile in a heel to toe orientation,FIG. 8of the accompanying drawings provides a cross-sectional view of a golf club head800taken along cross-sectional line A-A′ shown inFIG. 2.

FIG. 8of the accompanying drawings shows a cross-sectional view of a golf club head800taken along cross-sectional line A-A′ shown inFIG. 2allowing the continuously variable sole profile of the golf club head800to be shown more clearly. In this cross-sectional view, it can be seen that the radius of curvature of the sole802not only various continuously in a front to back context, but is also continuously variable in the heel808to toe806direction. In this cross-sectional view, it can be seen that the radius of curvature at the heel808and toe806ends of the golf club head800is dramatically lower than it is at the center of the sole802, meaning the heel808and toe806ends are more curved. More specifically, it can be said that in this current embodiment of the present invention, the toe806portion of the sole802may have a radius of curvature less than about 40 mm, the heel portion808of the sole may have a radius of curvature of less than about 30 mm; all while the center portion of the sole802may have a radius of curvature of greater than about 70 mm.

Other than in the operating example, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for amounts of materials, moment of inertias, center of gravity locations, loft, draft angles, various performance ratios, and others in the aforementioned portions of the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear in the value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the above specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.