Patent Grant
8579729
The present invention relates generally to a wedge type golf club head with a lower center of gravity. More specifically, the present invention relates to a wedge type golf club head that has a high loft and a low center of gravity allowing for increased back spin, increased launch angle, and increased ball speed. In addition to the above, the present invention also discloses a golf club head with an increased topline thickness that varies with the loft of the golf club head.
Golf clubs, combined with golf balls, have generally been considered to be the most essential equipment in the game of golf. Progressing in parallel with the development of the game of golf, significant developments have occurred within the golf equipment industry. Golf clubs, especially wedge type golf clubs, have also developed simultaneously with all other types of golf equipment to accommodate for the needs of the golfer to hit their shots more accurately and with more control.
Wedge type golf clubs, more commonly known as wedges, are a particular type of golf club that generally has a higher loft angle. These higher lofted wedges tend to be precision instruments that allow a golfer to dial in short range golf shots with improved trajectory, improved accuracy, and improved control. This increased loft angle in wedges generally yield a golf shot with a higher trajectory because of the impact surface with the golf ball is not perpendicular to the trajectory of the club head; but rather, the golf ball interacts with the wedge at an inclination closely resembling the actual loft angle of the wedge itself. This inclination generally causes the golf ball to move up along the inclination of the wedge when struck by the wedge type golf club head, creating a backward rotation of the golf ball as it leaves the wedge club face. This backwards rotation of the golf ball is generally known as “backspin” within the golf industry; and it is desirable in helping improve trajectory, accuracy, and control of a wedge type golf shot.
Backspin helps improve trajectory, accuracy, and control of a golf shot by giving the golf ball a gyroscopic effect, which stabilizes ball flight, hence increasing accuracy. Moreover, backspin also serves to increase control of a golf shot as backspin minimizes the roll of a golf ball after landing, creating a more predictable golf shot even after it lands on the ground.
A number of methods are generally known in the golf club art to increase backspin. For example, one method to generate increased backspin may be increasing the coefficient of friction of the wedge club face. U.S. Pat. No. 5,804,272 to Schrader titled Backspin Sticker ('272 patent) generally discloses a combination of a backspin sticker and a golf club having an angled surface for increasing the backspin of a golf ball when it hits the putting surface. More specifically, the '272 patent discloses a sticker, shaped to conform to a hitting area on the hitting surface, the sticker having a front surface with a coating of silicon carbide grain affixed with a synthetic resin and an adhering region having a clear, pressure sensitive adhesive applied thereon.
U.S. Pat. Pub. No. US 2004/0127300 to Roesgen et al. titled Golf Clubhead ('300 patent publication) is another example of a methodology used to increase backspin of a wedge type golf club by increasing coefficient of friction of the wedge club face. The '300 patent publication generally discloses a golf clubhead made from metal, having a strike face which has a loft angle α of greater than 45°, the strike face having a plurality of parallel grooves, where the strike face has a surface roughness Ra of less than 0.25 micrometer, and a Vickers hardness of the strike face greater than 5 GigaPascal.
Although the surface treatments discussed above may be effective in increasing the backspin of a golf ball, surface treatments often suffer from gradual wear and tear, making them less optimal. In order to address that issue, U.S. Pat. No. 7,014,568 to Pelz for a Golf Club ('568 patent) discloses a wedge face groove configuration that may also be beneficial in increasing backspin. More specifically, the '568 patent discloses a wedge hitting surface may take the form of an insert that includes a series of grooves, the design of which is varied from club to club to provide increasing friction with loft. Even more specifically, the wedges may utilize a club face of a constant surface roughness so that, regardless of club loft, the surface friction is kept constant and only the grooves of each club are varied to provide the changing impact friction required to provide constant spin rate.
U.S. Pat. No. 5,437,088 to Igarashi for a Method of Making a Golf Club that Provides Enhanced Backspin and Reduced Sidespin ('088 patent) also discloses a groove configuration that achieves increased backspin of a golf ball. More specifically, the '088 patent discloses an improved golf club wherein the surface of the face of the club is substantially flat, which is achieved by surfacing (milling) the club face, and wherein the edges of scoring lines (grooves) are made relatively sharp as a result of the surfacing operation. The sharp groove edges (and milling lines) of the present invention produce enhanced backspin and reduced sidespin when a golf ball is struck, which results in a relatively straight golf ball flight path, notwithstanding a glancing club impact angle.
As it can be seen from above, numerous attempts have been made to improve the backspin of a golf ball, especially when being hit with a wedge type golf club. However, the current methodology of utilizing either a surface treatment or groove configurations does not maximize the inherent potential of a wedge type golf club. More specifically, the current methodology does not take in to consideration the potential backspin and out going ball speed benefits that can be achieved by a wedge type golf club if the center of gravity (CG) location is shifted towards an alternate location that maximizes the efficiency of energy transfer between the wedge type golf club head and a golf ball.
Having a CG 102 location that is so high above ground 106 may generally be undesirable as it does not maximize the efficiency of energy transfer between the wedge type golf club head 100 and a golf ball. In order to maximize the efficiency of energy transfer between the wedge type golf club head 100 and a golf ball, it is generally desirable to have the CG 102 in closer proximity to the ground 106, and more preferably along an axis of impact perpendicular to the hitting surface that runs through the CG of the golf club and the center of the golf ball.
In addition to the increased backspin benefits that can be achieved by maximizing the CG location of a wedge type golf club, maximizing the CG location will also allow for increased performance characteristics such as increased ball speed and increased launch angle that correlates into increased trajectory, increased accuracy, and increased control. Increased ball speed will yield increased shot distance. If an increased spin is desired while keeping shot distance constant, the wedge loft will have to be increased, a characteristic which will mitigate the ballspeed increase while adding even more backspin to the ball, yielding even more overall stopping power or accuracy.
With respect to the ability of the golf club head to have an increased topline thickness that varies with the loft of the golf club head to improve the performance of the wedge type golf club head, the prior art, U.S. Pat. No. 5,547,426 to Wood discloses a golf club head using progressively sized heads having slots of selected depths in the back of the golf club head. These golf club heads may have a progressive top edge thickness so that all top edge appear to have the same width in use, but it makes no attempt to utilize and adjust this variation in topline thickness to improve the moment of inertia of the golf club head.
Hence, it can be seen that there is a need in the field for a golf club that is capable of improving the backspin characteristics without the need to either adjust the grooves or provide surface treatment to the wedge type club face. More specifically, there is a need in the field for a wedge type golf club that is capable of optimizing the performance characteristics of a golf shot such as backspin, ball speed, and launch angle by utilizing strategically placed CG locations within the wedge type golf club. The CG optimized wedge type golf club head that has improved performance characteristics may then be used in conjunction with a wedge type golf club head with various grooves or surface treatments to further optimize the backspin characteristics of a wedge type golf club head.
In one aspect of the present invention is a wedge type golf club head comprising of a hosel and a body attached to the hosel, creating a loft angle. The body is further comprising of a hitting surface and a rear portion wherein the hitting surface defines a neutral axis perpendicular to the hitting surface passing through an impact point on the hitting surface. The wedge type golf club head also comprises of a sole at the bottom of the body at least partially resting on a ground connecting the hitting surface and the rear portion, wherein the loft angle is greater than about 45 degrees and wherein a center of gravity of the wedge type golf club head is located behind the hitting surface substantially along the neutral axis.
In another aspect of the present invention is a wedge type golf club head comprising of a hosel and a body attached to the hosel creating a loft angle, wherein the body comprises of a hitting surface and a rear portion. The wedge type golf club head also comprises of a sole at a bottom of the body at least partially resting on a ground connecting the hitting surface and the rear portion, wherein the loft angle is greater than about 45 degrees, wherein the sole further comprises of a weighted portion, and wherein a density of the weighted portion is greater than a density of the remainder of the wedge type golf club head.
In a further aspect of the present invention is a wedge type golf club head comprising of a hosel and a body attached to the hosel, creating a loft angle. The body is further comprising of a hitting surface and a rear portion wherein the hitting surface defines a neutral axis perpendicular to the hitting surface passing through an impact point on the hitting surface. The wedge type golf club head also comprises of a sole at the bottom of the body at least partially resting on a ground connecting the hitting surface and the rear portion, wherein the loft angle is greater than about 45 degrees, and wherein the center of gravity of the wedge type golf club head is located within a parabolic region of the wedge type golf club head that is bisected by the neutral axis. The parabolic region is further comprised of a vertex located at the impact point of the hitting surface and the open direction of the parabolic region is pointed towards the rear portion of the body of the wedge type golf club head.
In an even further aspect of the present invention is a wedge type golf club head comprising of a hosel and a body attached to the hosel, creating a loft angle. The body is further comprising of a hitting surface and a rear portion wherein the hitting surface defines a neutral axis perpendicular to the hitting surface passing through an impact point on the hitting surface. The wedge type golf club head also comprises of a sole at the bottom of the body at least partially resting on a ground connecting the hitting surface and the rear portion, wherein the loft angle is greater than about 45 degrees and wherein the wedge type golf club head has a Performance Ratio of greater than about 530,000 rpm*mph.
In an even further aspect of the invention is a wedge type golf club head that needs to have an added loft in order to mitigate the ballspeed increase produced by the lowered CG in the current wedge type golf club head. This will add additional backspin and keep the overall wedge shot distance constant; which is a desirable trait among players with relatively high swing speeds to club distances in the set doesn't overlap one another.
These and other features, aspects and advantages of the present invention will become better understood with references to the following drawings, description and claims.
The foregoing and other features and advantages of the invention will be apparent from the following description of the invention as illustrated in the accompanying drawings. The accompanying drawings, which are incorporated herein and form a part of the specification, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.
The following detailed description is the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
Various inventive features described below can each be used independently of one another or in combination with other features. However, any single inventive feature may not address any or all of the problems discussed above or may only address one of the problems discussed above. Further, one or more of the problems discussed above may not be fully addressed by any of the features described below.
Neutral axis 208, as shown in the current exemplary embodiment, may generally be an arbitrary line that is ninety degrees and perpendicular to the hitting surface 201. In addition to being perpendicular to the hitting surface 201, this neutral axis 208 may also generally pass through the hitting surface 201 at an impact point 204 in accordance with the present invention. The neutral axis 208 generally determines the path of travel of a golf ball after impacting the wedge type golf club head 200, and the neutral axis is further defined by the CG 202 location of the wedge type golf club head as the neutral axis 208 also passes through the CG 202 location.
The wedge type golf club head 200, as shown in the current exemplary embodiment, may generally have a CG 202 location significantly lower than that of a prior art wedge type golf club head 100. (See
Having a CG 202 location directly on the neutral axis 208 may generally help improve the performance characteristics of a wedge type golf club head 200 by improving energy transfer efficiency and generate more momentum along the impact direction. This improved energy transfer generates more momentum and may directly improve the backspin, the ball speed, and the launch angle of a golf ball that is struck by the wedge type golf club head 200 irrespective of the grooves on the hitting surface 201 of the wedge type golf club head 200. It should be noted that significant improvements in the performance characteristics may be achieved just by having the CG 202 substantially along the neutral axis 208 and perfect alignment is not necessary. To achieve the significantly improved performance characteristic, the CG 202 location may be any location behind hitting face 201 and preferably at a location substantially along the neutral axis 208 in accordance with an embodiment of the present invention.
Impact point 204 may generally depict the point where a golf ball will come into contact with the wedge type golf club head 200. To put in another way, impact point may generally be the location where most golfers will hit a golf ball when utilizing a wedge type golf club head. Impact point 204, as shown in the current exemplary embodiment, may generally be 10 mm to 20 mm from ground 206; however, impact point 204 may be more preferably 12 mm to 18 mm from ground 206 or even more preferably from 14 mm to 16 mm from ground 206, and most preferably 15 mm from ground 206 all without departing from the scope and content of the present invention. The impact point 204, may help define the upper limit of the CG 202 location that is a distance d2 away from ground 206. Distance d2, as shown in the current exemplary embodiment may generally be less than 20 mm from ground 206, however, CG 202 location may more preferably be less than 18 mm from ground 206 or even more preferably less than 16 mm from ground 206, and most preferably less than 15 mm from ground 206 all without departing from the scope and content of the present invention.
Loft angle α, as shown in the current exemplary embodiment, may generally be directed towards a higher lofted club such as a wedge type golf club head 200. Wedge type golf club head 200, may generally have a loft angle α greater than 45 degrees; however loft angle α may be less then 45 degrees, or even exactly at 45 degrees all without departing from the scope and content of the present invention so long as the wedge type golf club head 200 could benefit from the enhanced performance that is achievable from the optimized CG 202 location associated with a wedge type golf club head 200.
As it can be seen from
The size of the parabolic region 620 may generally determine the CG locations that may be substantially along the neutral axis 608. More specifically, parabolic region 620, may generally define a region that will ensure that the CG location be within 7 mm of neutral axis 608; more preferably no greater than 5 mm; and most preferably no greater than 3 mm all without departing from the scope and content of the present invention. The perimeter of the parabolic region 620 may generally depict the region that will encompass the CG locations that will help achieve higher backspin, higher ball speed, and higher launch angle of a golf ball in accordance with the exemplary embodiment of the present invention.
The parabolic region 620 as shown in
Weighted portion 732, as shown in the current exemplary embodiment, may generally be comprised of a second material having a relatively high density such as tungsten; however, numerous other materials such as tungsten nickel, lead, copper, iridium, or any other material with a high density may all be used without departing from the scope and content of the present invention. The remainder of the wedge type golf club head 700, inversely, may generally be comprised of a standard material that has a lower density than that of the weighted portion 732. Wedge type golf club head 700, may generally be comprised of steel, however, numerous other materials such as aluminum, iron, copper, titanium, or even plastic so long as it has a density lower than that of the weighted portion 732 all without departing from the scope and content of the present invention.
In an exemplary embodiment of the present invention, weighted portion 732 may have a density of about 19300 kg/cubic meters when it is comprised of a material such as tungsten. Alternatively, the remainder of the wedge type golf club head 700 may have a density of about 7800 kg/cubic meters when it is comprised of a material such as steel. This relationship of the density between the weighted portion 732 and the remainder of the wedge type golf club head 700 may generally create a weight ratio that is greater than 2.0, more preferably greater than 2.25, and most preferably greater than 2.5; wherein the weight ratio is defined by the density of the weighted portion 732 over density of the remainder of the wedge type golf club head 700.
Weighted portion 732, as shown in
Finally, it should be noted that because a wedge type golf club head in accordance with the present invention performs so well beyond the actual loft that it is labeled with and measured at, the labeling of the loft angle may need to be adjusted to maintain the same performance numbers previously associated with various wedge type golf club heads. For example, a 55 degree wedge in accordance with the current exemplary invention could very easily achieve performance numbers traditionally associated with a prior art 54 degree wedge without the optimized CG location.
As it can be seen from
Although
Finally, returning to
Described below for comparative purposes, a prior art wedge type golf club head 100 may have a launch angle of about 27.1 degrees, a ball speed of about 86.9 mph, a backspin rate of about 12138 rpm, and a loft of about 54 degrees; yielding a Performance Ratio of approximately 529,349 rpm*mph. Wedge type golf club head 200, in accordance with an exemplary embodiment of the present invention, may generally have a launch angle of about 27.4 degrees, a ball speed of about 88.2 mph, a backspin rate of about 12330 rpm, and a loft of about 54 degrees; yielding a Performance Ratio of approximately 551,808 rpm*mph. The change in Performance Ratio from a prior art wedge type golf club head 100 to wedge type golf club head 200, as shown in the current exemplary embodiment, may be approximately 22,459 rpm*mph signifying an increased of performance characteristic without departing from the scope and content of the present invention.
In the exemplary embodiment of the golf club head 1700 shown in
In addition to preventing the golf club head from twisting for shots at different heights above the neutral axis, this improved MOI will also improve the performance of the golf club head by preventing a golf ball from sliding up the face of the golf club head 1700 during impact. Because wedge type golf club head may generally have a higher loft angle α, a golf ball that contacts the hitting surface of the golf club head 1700 will be more likely to slide up the face of the golf club head 1700 during impact. Having a golf club head 1700 with a higher moment of inertia along the x-axis will allow the golf club head 1700 to remain steady during impact with a golf ball even at different impact heights, minimizing any movement of the golf club head 1700 despite this higher loft angle α.
Because the actual first thickness d18 of the thickened upper portion 1766 may be one of the more important factors that affect the MOI of a golf club head 1700 along the x-axis, the exact first thickness d18 of the thickened upper portion 1766 may need to be defined relative to the loft α of the golf club head 1700. Hence, in order to quantify this specific relationship between the thickness d18 and the loft α, a “Topline Thickness Ratio” may be defined as shown below by equation (2) below:
“Topline Thickness Ratio”, as demonstrated by the current exemplary embodiment of the present invention, may generally be greater than about 6.0 degrees/mm and less than about 9.0 degrees/mm, more preferably greater than about 7.0 degrees/mm and less than about 9.0 degrees/mm, and most preferably greater than about 8.0 degrees/mm and less than about 9.0 degrees/mm. The Topline Thickness Ratio of the current inventive golf club head compared to a prior art golf club head can be found in Table 1 below.
Although somewhat related to the Topline Thickness Ratio, it is worth recognizing here that Table 1 also shows the first thickness d18 getting progressively thicker as the loft α of the golf club head 1700 increases. This progressive increase in the first thickness d18 of the thickened upper portion 1766 is important to the performance of the golf club head 1700 because the higher lofted golf club heads would generally require a thicker upper portion 1766 to provide more stability.
In addition to the thickness d18 of the thickened upper portion 1766, table 1 above also shows the second thickness d16 of the thinned portion 1735 of the golf club head 1700. Second thickness d16 may be used to calculate a thickness difference of the rear portion of the golf club head, which provides an alternative methodology to quantify the increasing thickness d16 as it relates to the remainder of the golf club head 1700. A golf club head 1700 in accordance with the current exemplary embodiment of the present invention may generally have a thickness difference of greater than about 0.4 mm, more preferably greater than about 1.0 mm, and most preferably greater than about 1.5 mm. This thickness difference can then be used to calculate a “Thickness Difference Ratio”, which provides an alternative way to capture the performance enhancements of the golf club head 1700, defined by equation (3) below:
Thickness Difference Ratio, as it can be seen from above, provides a relationship between the loft of the golf club head 1700 and the thickness difference. The golf club head 1700 in accordance with the exemplary embodiment of the present invention may generally have a Thickness Difference Ratio of greater than 25 degrees/mm, more preferably greater than 27.5 degrees/mm, and most preferably greater than 30 degrees/mm.
One advantage of the golf club head 2000 shown in
Although the present embodiment shows three inserts in order to offer an ability to adjust the CG of the golf club head 2000, numerous other number combinations of inserts may be used without departing from the scope and content of the present invention. More specifically, the golf club head 2000 may have two inserts, four inserts, five inserts, or any number of inserts that can fit within the upper chamber 2062 all without departing from the scope and content of the present invention.
Finally,
Other than in the operating examples, 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 and draft angles, and others in the preceding portions of the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear with the value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the preceding 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.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Furthermore, when numerical ranges of varying scope are set forth herein, it is contemplated that any combination of these values inclusive of the recited value may be used.
It should be understood, of course, that the foregoing relates to exemplary embodiments of the present invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
The present application is a Continuation-In-Part of co-pending U.S. patent application Ser. No. 12/832,488, filed on Jul. 8, 2010, which is a Continuation-In-Part of U.S. patent application Ser. No. 12/474,316, filed on May 29, 2009 now U.S. Pat. No. 8,187,120; the disclosure of which are all incorporated by reference in their entirety.
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| Number | Date | Country | |
|---|---|---|---|
| 20120129628 A1 | May 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12832488 | Jul 2010 | US |
| Child | 12957562 | US | |
| Parent | 12474316 | May 2009 | US |
| Child | 12832488 | US |
