Patent Application
20190381370
The present disclosure relates to a golf club head. More specifically, the present disclosure relates to an iron-type golf club head having a unique face construction.
When a golf club head strikes a golf ball, a force is seen on the club head at the point of impact. If the point of impact is aligned with the center face of the golf club head in an area of the club face typically called the sweet spot, then the force has minimal twisting or tumbling effect on the golf club. However, if the point of impact is not aligned with the center face, outside the sweet spot for example, then the force can cause the golf club head to twist around the center face. This twisting of the golf club head causes the golf ball to acquire spin. For example, if a typical right handed golfer hits the ball near the toe of the club this can cause the club to rotate clockwise when viewed from the top down. This in turn causes the golf ball to rotate counter-clockwise which will ultimately result in the golf ball curving to the left. This phenomenon is what is commonly referred to as “gear effect.”
Bulge and roll are golf club face properties that are generally used to compensate for this gear effect. The term “bulge” on a golf club typically refers to the rounded properties of the golf club face from the heel to the toe of the club face.
The term “roll” on a golf club typically refers to the rounded properties of the golf club face from the crown to the sole of the club face. When the club face hits the ball, the ball acquires some degree of backspin. Typically this spin varies more for shots hit below the center line of the club face than for shots hit above the center line of the club face.
A golf club design is needed to counteract the left and right tendency that a player encounters when the ball impacts a high or low position on the club head striking face.
The problems noted above are equally applicable to iron-type golf clubs or “irons.” While all clubs in a golfer's bag are important, both scratch and novice golfers rely on the performance and feel of their irons for many commonly encountered playing situations.
Irons are generally configured in a set that includes clubs of varying loft, with shaft lengths and clubhead weights selected to maintain an approximately constant “swing weight” so that the golfer perceives a common “feel” or “balance” in swinging both the low irons and high irons in a set. The size of an iron's “sweet spot” is generally related to the size (i.e., surface area) of the iron's striking face, and iron sets are available with oversize club heads to provide a large sweet spot that is desirable to many golfers.
Conventional “blade” type irons have been largely displaced (especially for novice golfers) by so-called “perimeter weighted” irons, which include “cavity-back” and “hollow” iron designs. Cavity-back irons have a cavity directly behind the striking plate, which permits club head mass to be distributed about the perimeter of the striking plate, and such clubs tend to be more forgiving to off-center hits. Hollow irons have features similar to cavity-back irons, but the cavity is enclosed by a rear wall to form a hollow region behind the striking plate. Perimeter weighted, cavity back, and hollow iron designs permit club designers to redistribute club head mass to achieve intended playing characteristics associated with, for example, placement of club head center of gravity or a moment of inertia.
In addition, even with perimeter weighting, significant portions of the club head mass, such as the mass associated with the hosel, topline, or striking plate, are unavailable for redistribution. The striking plate must withstand repeated strikes both on the driving range and on the course, requiring significant strength for durability.
Golf club manufacturers are consistently attempting to design golf clubs that are easier to hit and offer golfers greater forgiveness when the ball is not struck directly upon the sweet spot of the striking face. As those skilled in the art will certainly appreciate, many designs have been developed and proposed for assisting golfers in learning and mastering the very difficult game of golf.
With regard to iron type club heads, cavity back club heads have been developed. Cavity back golf clubs shift the weight of the club head toward the outer perimeter of the club. By shifting the weight in this manner, the center of gravity of the club head is pushed toward the sole of the club head, thereby providing a club head that is easier to use in striking a golf ball. In addition, weight is shifted to the toe and heel of the club head, which helps to expand the sweet spot and assist the golfer when a ball is struck slightly off center.
Shifting weight to the sole lowers the center of gravity (CG) of the club resulting in a club that launches the ball more easily and with greater backspin. Golf club designers may measure the vertical CG of the golf club relative to the ground when the golf club is soled and in the proper address position, this CG measurement will be referred to as Zup or Z-up or CG Z-up. Decreasing Z-up as opposed to increasing it is preferable. Golf club designers can use a golf club with a low Z-up to design clubs for both low and high handicap golfers by either making a golf club that maintains similar launch angles but increases ball speed and distance or a club that launches the ball more easily in the air. Higher handicap golfers typically have trouble launching the ball in the air so a club that gets the ball in the air more easily is a great benefit. For lower handicap golfers, launching the ball in the air is not typically an issue. For lower handicap golfers, golf club designers may strengthen the loft of the golf club to maintain similar launch conditions and similar amounts of backspin, but resulting in greater ball speed and distance gains of several yards. The result is better golfers may now use one less club when approaching a green, such as, for example, a golfer may now use a 7-iron instead of a 6-iron to hit a green. Placing weight at the toe increases the moment of inertia (MOI) of the golf club resulting in a club that resists twisting and is thereby easier to hit straight even on mishits.
As club manufacturers have learned to assist golfers by shifting the center of gravity toward the sole of the club head, a wide variety of designs have been developed. Unfortunately, many of these designs substantially alter the appearance of the club head while attempting to shift the center of gravity toward the sole and perimeter of the club head. For example, one method of lowering the CG is to simply decrease the face height at the toe and make it closer in height to the face height at the heel of the club resulting in a very untraditional looking club. This is highly undesirable as golfers become familiar with a certain style of club head and alteration of that style often adversely affects their mental outlook when standing above a ball and aligning the club head with the ball. As such, a need exists for an improved club head which achieves the goal of shifting the center of gravity further toward the sole and perimeter of the club head without substantially altering the appearance of a traditional cavity back club head with which golfers have become comfortable. The present invention provides such a club head.
Unfortunately, an additional problem arises from relocating mass on a golf club in that the acoustical properties of the golf club head is often negatively impacted. The acoustical properties of golf club heads, e.g., the sound a golf club head generates upon impact with a golf ball, affect the overall feel of a golf club by providing instant auditory feedback to the user of the club. For example, the auditory feedback can affect the feel of the club by providing an indication as to how well the golf ball was struck by the club, thereby promoting user confidence in the club and himself.
The sound generated by a golf club is based on the rate, or frequency, at which the golf club head vibrates and the duration of the vibration upon impact with the golf ball. Generally, for iron-type golf clubs, a desired first mode frequency is generally around 3,000 Hz and preferably greater than 3,200 Hz. A frequency less than 3,000 Hz may result in negative auditory feedback and thus a golf club with an undesirable feel. Additionally, the duration of the first mode frequency is important because a longer duration results in a ringing sound and/or feel, which feels like a mishit or a shot that is not solid. This results in less confidence for the golfer even on well struck shots. Generally, for iron-type golf clubs, a desired first mode frequency duration is generally less than 10 ms and preferably less than 7 ms.
Accordingly, it would be desirable to reduce the topline weight to shift the CG to the sole and/or toe while maintaining acceptable vibration frequencies and durations. Such a club would be easier to hit because it would launch the ball more easily (low CG) and/or hit the ball straighter even on mishits (increased MOI), and the club would still provide desirable feel through positive auditory feedback. Accordingly, there exists a need for iron-type golf club heads with a strong and lightweight topline.
Golf clubs are typically manufactured with standard lie and loft angles. Some golfers prefer to modify the lie and loft angles of their golf clubs in order to improve the performance and consistency of their golf clubs and thereby improve their own performance.
In some cases, golf club heads, particularly iron-type golf club heads, can be adjusted by being plastically bent in a post-manufacturing process. In such a bending process, it can be difficult to plastically bend the material of the club head in a desired manner without adversely affecting the shape or integrity of the hosel bore, the striking face, or other parts of the club head. In addition, advancements in materials and manufacturing processes, such as extreme heat treatments, have resulted in club heads that are stronger and harder to bend and have more sensitive surface finishes. This increases the difficulty in accurately bending a club head in a desired manner without adversely affecting the club head. Additionally, the iron-type club heads must have a hosel design that will allow for bending. Bending bars are used for bending golf club heads to a golfer's preferred loft and lie. The bending process requires a significant amount of force and/or torque to plastically deform the iron-type club head. It can be difficult to plastically bend the club head in a desired manner without adversely affecting the shape or integrity of the hosel bore, the striking face, or other parts of the club head. As a result the hosel must have significant structural integrity to withstand multiple bending sessions and repeated strikes at the range and the golf course. The risk of club failure makes for a challenging design problem and makes the mass associated with the hosel largely unavailable for redistribution.
Accordingly, there exists a need for iron-type golf club heads with strong and lightweight hosels, centers of gravity shifted toward the sole, and/or a strong lightweight topline that can counteract the left and right tendency that a player encounters when the ball impacts a high or low position on the club head striking face.
Certain embodiments of the disclosure pertain to iron-type golf club heads with twisted striking faces. In one representative embodiment, an iron-type golf club head comprises a hosel portion, a heel portion, a sole portion, a toe portion, a topline portion, and a striking face having a center face location. A center face vertical plane passes through the center face location, extends from adjacent the topline portion to adjacent the sole portion and intersects with the striking face surface to define a center face topline-to-sole contour. A toe side vertical plane is spaced away from the center face vertical plane by 14 mm toward the toe portion, extends from adjacent the topline portion to adjacent the sole portion and intersects with the striking face surface to define a toe side topline-to-sole contour. A heel side vertical plane is spaced away from the center face vertical plane by 14 mm toward the heel portion, extends from adjacent the topline portion to adjacent the sole portion and intersects with the striking face surface to define a heel side topline-to-sole contour. A center face horizontal plane passes through the center face location, extends from adjacent the toe portion to adjacent the heel portion and intersects with the striking face surface to define a center face toe-to-heel contour. A topline side horizontal plane is spaced away from the center face horizontal plane by 15 mm toward the topline portion, extends from adjacent the toe portion to adjacent the heel portion and intersects with the striking face surface to define a topline side toe-to-heel contour. A sole side horizontal plane is spaced away from the center face horizontal plane by 15 mm toward the sole portion, extends from adjacent the toe portion to adjacent the heel portion and intersects with the striking face surface to define a sole side toe-to-heel contour. The toe side topline-to-sole contour is more lofted than the center face topline-to-sole contour, the heel side topline-to-sole contour is less lofted than the center face topline-to-sole contour, the topline side toe-to-heel contour is more open than the center face toe-to-heel contour, and the sole side toe-to-heel contour is more closed than the center face toe-to-heel contour. The toe side topline-to-sole contour, the center face topline-to-sole contour, the heel side topline-to-sole contour, the topline side toe-to-heel contour, the center face toe-to-heel contour, and the sole side toe-to-heel contour are straight line contours.
In some embodiments, a critical point located at 15 mm above the center face location has a LA ° Δ that is substantially unchanged relative to a 0° twist golf club head.
In some embodiments, a critical point located at 15 mm above the center face location has a FA ° Δ of between 0.1° and 4° relative to the center face location.
In some embodiments, a critical point located at 15 mm above the center face location has a FA ° Δ of between 0.25° and 3° relative to the center face location.
In some embodiments, a critical point located at 15 mm below the center face location has a FA ° Δ of between −0.1° and −4° relative to the center face location.
In some embodiments, a critical point located at 15 mm below the center face location has a FA ° Δ of between −0.25° and −3° relative to the center face location. In some embodiments, an average FA ° Δ of an upper toe quadrant of the striking face is between 0.275° to 4.4°.
In some embodiments, a toe side point located at a x-z coordinate of (14 mm, 15 mm) has a LA ° Δ relative to the center face location that is between 0.23° and 2.8°, and a heel side point located at a x-y coordinate of (−14 mm, −15 mm) has a LA ° Δ relative to the center face location that is between 0.23° and −2.8°.
In some embodiments, an average LA ° Δ of an upper toe quadrant of the striking face is between 0.245° to 3°.
In some embodiments, the striking face has a degree of twist that is between 0.1° and 5° when measured between two critical locations located at 15 mm above the center face location and 15 mm below the center face location.
In another representative embodiment, an iron-type golf club head comprises a hosel portion, a heel portion, a sole portion, a toe portion, a topline portion, and a striking face having a center face location. A center face vertical plane passes through the center face location, extends from adjacent the topline portion to adjacent the sole portion and intersects with the striking face surface to define a center face topline-to-sole contour. A toe side vertical plane is spaced away from the center face vertical plane by 14 mm toward the toe portion, extends from adjacent the topline portion to adjacent the sole portion and intersects with the striking face surface to define a toe side topline-to-sole contour. A heel side vertical plane is spaced away from the center face vertical plane by 14 mm toward the heel portion, extends from adjacent the topline portion to adjacent the sole portion and intersects with the striking face surface to define a heel side topline-to-sole contour. A center face horizontal plane passes through the center face location, extends from adjacent the toe portion to adjacent the heel portion and intersects with the striking face surface to define a center face toe-to-heel contour. A topline side horizontal plane is spaced away from the center face horizontal plane by 15 mm toward the topline portion, extends from adjacent the toe portion to adjacent the heel portion and intersecting with the striking face surface to define a topline side toe-to-heel contour. A sole side horizontal plane is spaced away from the center face horizontal plane by 15 mm toward the sole portion, extends from adjacent the toe portion to adjacent the heel portion and intersects with the striking face surface to define a sole side toe-to-heel contour. The toe side topline-to-sole contour is more lofted than the center face topline-to-sole contour, the heel side topline-to-sole contour is less lofted than the center face topline-to-sole contour, the topline side toe-to-heel contour is more open than the center face toe-to-heel contour, and the sole side toe-to-heel contour is more closed than the center face toe-to-heel contour, and a club head depth of the of the iron-type golf club head is between about 10 mm and about 50 mm.
In some embodiments, a critical point located at 15 mm above the center face location has a LA ° Δ that is substantially unchanged relative to a 0° twist golf club head.
In some embodiments, a critical point located at 15 mm above the center face location has a FA ° Δ of between 0.1° and 4° relative to the center face location.
In some embodiments, a critical point located at 15 mm above the center face location has a FA ° Δ of between 0.25° and 3° relative to the center face location.
In some embodiments, an average FA ° Δ of an upper toe quadrant of the striking face is between 0.275° to 4.4°.
In some embodiments, a toe side point located at a x-z coordinate of (14 mm, 15 mm) has a LA ° Δ relative to the center face location that is between 0.23° and 2.8°, and a heel side point located at a x-y coordinate of (−14 mm, −15 mm) has a LA ° Δ relative to the center face location that is between 0.23° and −2.8°.
In some embodiments, an average LA ° Δ of an upper toe quadrant of the striking face is between 0.245° to 3°.
In some embodiments, the striking face has a degree of twist that is between 0.1° and 5° when measured between two critical locations located at 15 mm above the center face location and 15 mm below the center face location.
In another representative embodiment, an iron-type golf club head comprises a hosel portion, a heel portion, a sole portion, a toe portion, a topline portion, and a striking face having a center face location; A center face vertical plane passes through the center face location, extends from adjacent the topline portion to adjacent the sole portion and intersects with the striking face surface to define a center face topline-to-sole contour. A toe side vertical plane is spaced away from the center face vertical plane by 14 mm toward the toe portion, extends from adjacent the topline portion to adjacent the sole portion and intersects with the striking face surface to define a toe side topline-to-sole contour. A heel side vertical plane is spaced away from the center face vertical plane by 14 mm toward the heel portion, extends from adjacent the topline portion to adjacent the sole portion and intersects with the striking face surface to define a heel side topline-to-sole contour. A center face horizontal plane passes through the center face location, extends from adjacent the toe portion to adjacent the heel portion and intersects with the striking face surface to define a center face toe-to-heel contour. A topline side horizontal plane is spaced away from the center face horizontal plane by 15 mm toward the topline portion, extends from adjacent the toe portion to adjacent the heel portion and intersecting with the striking face surface to define a topline side toe-to-heel contour. A sole side horizontal plane is spaced away from the center face horizontal plane by 15 mm toward the sole portion, extends from adjacent the toe portion to adjacent the heel portion and intersects with the striking face surface to define a sole side toe-to-heel contour. The toe side topline-to-sole contour is more lofted than the center face topline-to-sole contour, the heel side topline-to-sole contour is less lofted than the center face topline-to-sole contour, the topline side toe-to-heel contour is more open than the center face toe-to-heel contour, and the sole side toe-to-heel contour is more closed than the center face toe-to-heel contour, and the iron-type golf club head has a volume less than 110 cc.
In some embodiments, the iron-type golf club head has a volume of between about 30 cc and about 100 cc.
In some embodiments, the iron-type golf club head comprises a titanium alloy including 6.75% to 9.75% aluminum by weight and 0.75% to 3.25% molybdenum by weight.
The foregoing and other objects, features, and advantages of the disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
The technology of the present application is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements.
Various embodiments and aspects of the inventions will be described with reference to details discussed below, and the accompanying drawings will illustrate the various embodiments. The following description and drawings are illustrative of the invention and are not to be construed as limiting the invention. Numerous specific details are described to provide a thorough understanding of various embodiments of the present invention. However, in certain instances, well-known or conventional details are not described in order to provide a concise discussion of embodiments of the present inventions.
These dimensions are measured on horizontal lines between vertical projections of the outermost points of the heel and toe, face and back, and sole and crown. The outermost point of the heel is defined as the point on the heel that is 0.875″ above the horizontal ground plane 202.
A coordinate system for measuring CG location is located at the face center 220. In one embodiment, the positive x-axis 222 is projecting toward the heel side of the club head, the positive z-axis 250 is projecting toward the crown side of the club head, and the positive y-axis 216 is projecting toward the rear of the club head parallel to a ground plane.
In some embodiments, the golf club head can have a CG with a CG x-axis coordinate between about −5 mm and about 10 mm, a CG y-axis coordinate between about 15 mm and about 50 mm, and a CG z-axis coordinate between about −10 mm and about 5 mm. In yet another embodiment, the CG y-axis coordinate is between about 20 mm and about 50 mm.
Scorelines 224 are located on the striking face 206. In one exemplary embodiment, a projected CG location 226 is shown on the striking face and is considered the “sweet spot” of the club head. The projected CG location 226 is found by balancing the clubhead on a point. The projected CG location 226 is generally projected along a line that is perpendicular to the face of the club head. In some embodiments, the projected CG location 226 is less than 2 mm above the center face location, less than 1 mm above the center face, or up to 1 mm or 2 mm below the center face location 220.
The moment of inertia about the golf club head CG x-axis 260 is calculated by the following equation:
I
CGx=∫(y2+z2)dm
In the above equation, y is the distance from a golf club head CG xz-plane to an infinitesimal mass dm and z is the distance from a golf club head CG xy-plane to the infinitesimal mass dm. The golf club head CG xz-plane is a plane defined by the CG x-axis 260 and the CG z-axis 264. The CG xy-plane is a plane defined by the CG x-axis 260 and the CG y-axis 262.
Moreover, a moment of inertia about the golf club head CG z-axis 264 is calculated by the following equation:
I
CGz=∫(x2+y2)dm
In the equation above, x is the distance from a golf club head CG yz-plane to an infinitesimal mass dm and y is the distance from the golf club head CG xz-plane to the infinitesimal mass dm. The golf club head CG yz-plane is a plane defined by the CG y-axis 262 and the CG z-axis 264.
In certain implementations, the club head can have a moment of inertia about the CG z-axis, between about 450 kg·mm2 and about 650 kg·mm2, and a moment of inertia about the CG x-axis between about 300 kg·mm2 and about 500 kg·mm2, and a moment of inertia about the CG y-axis between about 300 kg·mm2 and about 500 kg·mm2.
With the type of “twisted” bulge and roll contour defined above, a ball that is struck in the upper portion of the face will be influenced by horizontal contour D. A typical shot having an impact in the upper portion of a club face will influence the golf ball to land left of the intended target. However, when a ball impacts the “twisted” face contour described above, horizontal contour D provides a general curvature that points to the right to counter the left tendency of a typical upper face shot.
Likewise, a typical shot having an impact location on the lower portion of the club face will land typically land to the right of the intended target. However, when a ball impacts the “twisted” face contour described above, horizontal contour F provides a general curvature that points to the left to counter the right tendency of a typical lower face shot. It is understood that the contours illustrated in
In order to determine whether a 2-D contour, such as A,B,C,D,E, or F, is pointing left, right, up, or down, two measurement points along the contour can be located 18.25 mm from a center location or 36.5 mm from each other. A first imaginary line can be drawn between the two measurement points. Finally, a second imaginary line perpendicular to the first imaginary line can be drawn. The angle between the second imaginary line of a contour relative to a line perpendicular to the center face location provides an indication of how open or closed a contour is relative to a center face contour. Of course, the above method can be implemented in measuring the direction of a localized curvature provided in a CAD software platform in a 3D or 2D model, having a similar outcome. Alternatively, the striking surface of an actual golf club can be laser scanned or profiled to retrieve the 2D or 3D contour before implementing the above measurement method. Examples of laser scanning devices that may be used are the GOM Atos Core 185 or the Faro Edge Scan Arm HD. In the event that the laser scanning or CAD methods are not available or unreliable, the face angle and the loft of a specific point can be measured using a “black gauge” made by Golf Instruments Co. located in Oceanside, Calif. An example of the type of gauge that can be used is the M-310 or the digital-manual combination C-510 which provides a block with four pins for centering about a desired measurement point. The horizontal distance between pins is 36.5 mm while the vertical distance between the pins is 12.7 mm.
When an operator is measuring a golf club with a black gauge for loft at a desired measurement point, two vertical pins (out of the four) are used to measure the loft about the desired point that is equidistant between the two vertical pins that locate two vertical points. When measuring a golf club with a black gauge for face angle at a desired measurement point, two horizontal pins (out of the four) are used to measure the face angle about the desired point. The desired point is equidistant between the two horizontal points located by the pins when measuring face angle.
The term “open” is defined as having a face angle generally pointing to the right of an intended target at address, while the term “closed” is defined as having a face angle generally pointing to the left of an intended target ad address. In one embodiment, the lower heel quadrant 520 is more “closed” than all the other quadrants, meaning it has a face angle, in the aggregate, that is pointing more left than any of the other quadrants.
If the edge of the striking surface 500 is not visually clear, the edge of the striking face 500 is defined as a point at which the striking surface radius becomes less than 127 mm. If the radius is not easily computed within a computer modeling program, three points that are 0.1 mm apart can be used as the three points used for determining the striking surface radius. A series of points will define the outer perimeter of the striking face 500. Alternatively, if a radius is not easily obtainable in a computer model, a 127 mm curvature gauge can be used to detect the edge of the face of an actual golf club head. The curvature gauge would be rotated about a center face point to determine the face edge.
In one illustrative example in
The positive x-axis 522 for face point measurements extends from the center face toward the heel side and is tangent to the center face. The positive y-axis 502 for face point measurements extends from the center face toward the crown of the club head and is tangent to the center face. The x-y coordinate system at center face, without a loft component, is utilized to locate the plurality of points P0-P36 and Q0-Q8, as described below. The positive z-axis 504 extends from the face center and is perpendicular to the face center point and away from the internal volume of the club head. The positive z-axis 504 and positive y-axis 502 will be utilized as a reference axis when the face angle and loft angle are measured at another x-y coordinate location, other than center face.
To further the understanding of what is meant by a “twisted face”,
It is understood that many degrees of twist are contemplated and the embodiments described are not limiting. For example, a golf club having a “0.25° twist”, “0.75° twist”, “1.25° twist”, “1.5° twist”, “1.75° twist”, “2.25° twist”, “2.5° twist”, “2.75° twist, “3° twist”, “3.25° twist”, “3.5° twist”, “3.75° twist”, “4.25° twist”, “4.5° twist”, “4.75° twist”, “5° twist”, “5.25° twist”, “5.5° twist”, “5.75° twist”, “6° twist”, “6.25° twist”, “6.5° twist”, “6.75° twist”, “7° twist”, “7.25° twist”, “7.5° twist”, “7.75° twist”, “8° twist”, “8.25° twist”, “8.5° twist”, “8.75° twist”, “9° twist”, “9.25° twist”, “9.5° twist”, “9.75° twist”, and “10° twist” are considered other possible embodiments of the present invention. A golf club having a degree of twist greater than 0°, between 0.25° and 5°, between 0.1° and 5°, between 0° and 5°, between 0° and 10°, or between 0° and 20° are contemplated herein.
Utilizing the grid pattern of
Table 1 shows the LA ° Δ and FA ° Δ relative to center face for points located along the vertical axis 700 and horizontal axis 702 (for example points Q1,Q2, Q3, and Q6). With regard to points located away from the vertical axis 700 and horizontal axis 702, the LA ° Δ and FA ° Δ are measured relative to a corresponding point located on the vertical axis 700 and horizontal axis 702, respectively.
For example, regarding point Q4, located in the upper toe quadrant of the golf club head at a coordinate of (−30 mm, 15 mm), the LA ° Δ is measured relative to point Q3 having the same vertical axis 700 coordinate at (0 mm, 15 mm). In other words, both Q3 and Q4 have the same y-coordinate location of 15 mm. Referring to Table 1, the LA ° Δ of point Q4 is 0.4° with respect to the loft angle at point Q3. The LA ° Δ of point Q4 is measured with respect to point Q3 which is located in a corresponding upper toe horizontal band 704.
In addition, regarding point Q4, located in the upper toe quadrant of the golf club head at a coordinate of (−30 mm, 15 mm), the FA ° Δ is measured relative to point Q1 having the same horizontal axis 702 coordinate at (−30 mm, 0 mm). In other words, both Q1 and Q4 have the same x-coordinate location of −30 mm. Referring to Table 1, the FA ° Δ of point Q4 is 0.2° with respect to the face angle at point Q1. The FA ° Δ of point Q4 is measured with respect to point Q1 which is located in a corresponding upper toe vertical band 706.
To further illustrate how LA ° Δ and FA ° Δ are calculated for points located within a quadrant that are away from a vertical or horizontal axis, the LA ° Δ of point Q8 is measured relative to a loft angle located at point Q6 within a lower heel quadrant horizontal band 708. Likewise, the FA ° Δ of point Q8 is measured relative to a face angle located at point Q2 within a lower heel quadrant vertical band 710.
In summary, the LA ° Δ and FA ° Δ for all points that are located along either a horizontal 702 or vertical axis 700 are measured relative to center face Q0. For points located within a quadrant (such as points Q4, Q5, Q7, and Q8) the LA ° Δ is measured with respect to a corresponding point located in a corresponding horizontal band, and the FA ° Δ of a given point is measured with respect to a corresponding point located in a corresponding vertical band. In
The reason that points located within a quadrant have a different procedure for measuring LA ° Δ and FA ° Δ is that this method eliminates any influence of the bulge and roll curvature on the LA ° Δ and FA ° Δ numbers within a quadrant. Otherwise, if a point located within a quadrant is measured with respect to center face, the LA ° Δ and FA ° Δ numbers will be dependent on the bulge and roll curvature. Therefore utilizing the horizontal and vertical band method of measuring LA ° Δ and FA ° Δ within a quadrant eliminates any undue influence of a specific bulge and roll curvature. Thus the LA ° Δ and FA ° Δ numbers within a quadrant should be applicable across any range of bulge and roll curvatures in any given head. The above described method of measuring LA ° Δ and FA ° Δ within a quadrant has been applied to all examples herein.
The relative LA ° Δ and FA ° Δ can be applied to any lofted driver, such as a 9.5°, 10.5°, 12° lofted clubs or other commonly used loft angles such as for drivers, fairway woods, hybrids, irons, or putters.
In Examples 1-4 of Table 1, the critical point Q3 has a LA ° Δ of +3.4° with respect to the center face. In some embodiments, a LA ° Δ at Q3 is between 0° and 7°, between 1° and 5°, between 2° and 4°, or between 3° and 4°. A FA ° Δ of greater than zero at the critical point Q3 (15 mm above the center face) is shown. The FA ° Δ at the critical point Q3 can be between 0° and 5°, between 0.1° and 4°, between 0.2° and 4°, or between 0.2° and 3°, in some embodiment. In addition, the critical point Q6 has a LA ° Δ of −3.4°, or less than zero, with respect to the center face for Examples 1-4. In some embodiments, a LA ° Δ at Q6 is between 0° and −7°, between −1° and −5°, between −2° and −4°, or between −3° and −4°. A FA ° Δ of less than zero at the critical point Q6 (−15 mm below the center face) is shown. In some embodiments, the FA ° Δ at the critical point Q6 can be between 0° and −5°, between −0.1° and −4°, between −0.2° and −4°, or between −0.2° and −3°. In Examples 1-4, the loft angle remains constant relative to center face at the critical points Q3,Q6 while the face angle changes relative to center face as the degree of twist is changed.
Examples 1-4 of Table 1 further show a heel side point Q2 located at a x-y coordinate (30 mm, 0 mm) where the LA ° Δ relative to center is −0.5°, −1°, −2°, and −4°, respectively, for each example. Therefore, a LA ° Δ of less than zero at the point Q2 is shown. In some embodiments, the LA ° Δ at the Q2 point is between 0° and −8°. In addition, Examples 1-4 at Q2 show a FA ° Δ of less than −4° relative to center face as the degree of twist gets larger. In some embodiments, the FA ° Δ at Q2 is between −0.2° and −10°, between −0.3° and −9°, or between −1° and −8°.
Examples 1-4 of Table 1 further show a toe side point Q1 located at a coordinate (−30 mm, 0 mm) where the LA ° Δ relative to center is 0.5°, 1°, 2°, and 4°, respectively. Therefore, a LA ° Δ of greater than zero at the point Q1 is shown. In some embodiments, the LA ° Δ at the Q1 point is between 0° and 8°, between 0.1° and 7°, between 0.2° and 6°, or between 0.3° and 5°. In addition, a FA ° Δ at Q1 can be between between 1° and 8°, between 2° and 7°, or between 3° and 6°.
Examples 1-4 of Table 1 further show at least one upper heel quadrant point Q5 having a FA ° Δ relative to point Q2 that is greater than 0.1°, greater than 0.2° or 0.3°. For instance, at point Q5, Examples 1, 2, 3, and 4 show a FA ° Δ relative to point Q2 of 0.3°, 0.5°, 0.9°, and 1.9°, respectively, which are all greater than 0.1°. Examples 1-4 of Table 1 also show at least one upper heel quadrant point Q5 having a LA ° Δ relative to point Q3 that is less than −0.2°. For instance, at point Q5, Examples 1, 2, 3, and 4 show a LA ° Δ relative to point Q3 of −0.5°, −1°, −2°, and −4°, respectively, which are all less than −0.1°, less than −0.3, or less than −0.4.
Examples 1-4 of Table 1 further show at least one upper toe quadrant point Q4 having a FA ° Δ relative to point Q1 that is greater than 0.1°. For instance, at point Q5, Examples 1, 2, 3, and 4 show a FA ° Δ relative to point Q1 of 0.2°, 0.4°, 1°, and 2°, respectively, which are all greater than 0.15°. Examples 1-4 of Table 1 also show at least one upper toe quadrant point Q4 having a LA ° Δ relative to point Q1 that is greater than 0.1°. For instance, at point Q4, Examples 1, 2, 3, and 4 show a LA ° Δ relative to point Q1 of 0.4°, 0.9°, 1.9°, and 3.9°, respectively, which are all greater than 0.2° or greater than 0.3°.
Examples 1-4 of Table 1 further show at least one lower heel quadrant point Q8 having a FA ° Δ relative to point Q2 that is less than −5.7°. For instance, at point Q8, Examples 1, 2, 3, and 4 show a FA ° Δ relative to point Q2 of −0.2°, −0.4°, −1°, and −2°, respectively, which are all less than −0.1°. Examples 1-4 of Table 1 also show at least one lower heel quadrant point Q8 having a LA ° Δ relative to point Q6 that is less than −0.1°. For instance, at point Q8, Examples 1, 2, 3, and 4 show a LA ° Δ relative to point Q6 of −0.5°, −1°, −2°, and −4.1°, respectively, which are all less than −0.2°, less than 0.3° or less than 0.4°.
Examples 1-4 of Table 1 further show at least one lower toe quadrant point Q7 having a FA ° Δ relative to point Q1 that is less than −0.1°. For instance, at point Q7, Examples 1, 2, 3, and 4 show a FA ° Δ relative to center of −0.3°, −0.5°, −0.9°, and −2°, respectively, which are all less than −0.2°. Examples 1-4 of Table 1 also show at least one lower heel quadrant point Q7 having a LA ° Δ relative to point Q6 that is greater than 0.2°. For instance, at point Q7, Examples 1, 2, 3, and 4 show a LA ° Δ relative to point Q6 of 0.5°, 1°, 2°, and 4°, respectively, which are all greater than 0.3° or greater than 0.4°.
Table 2 shows the same embodiments of Table 1 but provides the difference in LA ° Δ and FA ° Δ when compared to the golf club head with “0° twist” as the base comparison. Example 1 has up to +/−0.5° of LA ° Δ and up to +/−0.3 FA ° Δ when compared to the golf club head with “0° twist”. Example 2 has up to +/−1° of LA ° Δ and up to +/−0.5 FA ° Δ when compared to the golf club head with “0° twist”. Example 3 has up to +/−2° of LA ° Δ and up to +/−1 FA ° Δ when compared to the golf club head with “0° twist”. Example 4 has up to +/−4.1° of LA ° Δ and up to +/−2.1 FA ° Δ when compared to the golf club head with “0° twist”.
In Examples 1-4, the LA ° Δ and FA ° Δ relative to center face remains unchanged at the center face location (0 mm, 0 mm) when compared to the “0° twist” head. However, all other points away from the center face location in Examples 1-4 have some non-zero amount of either LA ° Δ or FA ° Δ.
Table 3 shows the same nine key points of measurement shown in Table 1. Specifically, points P0, P4, P9, P15, P20, P24, P27, P32, and P36 correspond to the locations of points Q0-Q8 in Table 1. However, additional points have been measured to provide a higher resolution of the twisted face in Examples 5 and 6.
Point P5 located at x-y coordinate (0 mm, 20 mm) and point P10 located at x-y coordinate (0 mm, −20 mm) are helpful in determining the extreme face angle changes further away from the center face. In Example 5 of Table 3 at point P5, the FA ° Δ is between 0.1° and 4°, between 0.2° and 3.5°, between 0.3° and 3°, between 0.4° and 3°, or between 0.5° and 2°. The LA ° Δ at point P5 is between 1° and 10°, between 2° and 8°, between 3° and 7°, or between 3° and 6°.
In Example 5 of Table 3 at point P10, the FA ° Δ is between −0.1° and −4°, between −0.2° and −3.5°, between −0.3° and −3°, between −0.4° and −3°, or between −0.5° and −2°. The LA ° Δ at point P10 is between −1° and −10°, between −2° and −8°, between −3° and −7°, or between −3° and −6°.
Table 3 and
The average of the FA ° Δ and LA ° Δ of the four points described in each quadrant are shown in Table 4 below.
Table 4 shows that average FA ° Δ in Example 5 for the upper toe quadrant and the upper heel quadrant are more open (more positive) than the 0° twist golf club head by more than 0.1°, more than 0.2°, more than 0.3°, or more than 0.4°. In some embodiments the upper toe quadrant and upper heel quadrant have an average FA ° Δ more open than the 0° twist golf club by between 0.1° to 0.8°, 0.2° to 0.6°, or 0.3° to 0.5° more open. The lower toe quadrant and lower heel quadrant of Example 5 has a FA ° Δ that is more closed (more negative) than the 0° twist golf club head. In some embodiments, the FA ° Δ relative to a 0° twist club head in the lower toe quadrant and lower heel quadrant is less than −0.1°, less than −0.2, less than −0.3, or less than −0.4. In some embodiments, the FA ° Δ relative to a 0° twist club head in the lower toe quadrant and lower heel quadrant is between −0.1° to −0.8°, −0.2° to −0.6°, or −0.3° to −0.5°. Table 4 shows that average FA ° Δ in Example 6 for the upper toe quadrant and the upper heel quadrant are more open (more positive) than the 0° twist golf club head by more than 0.6°, more than 0.7°, more than 0.8°, or more than 0.9°. In some embodiments the upper toe quadrant and upper heel quadrant are more open than the 0° twist golf club by between 0.6° to 1.2°, 0.7° to 1.1°, or 0.8° to 1° more open. The lower toe quadrant and lower heel quadrant of Example 6 has a FA ° Δ that is more closed (more negative) than the 0° twist golf club head. In some embodiments, the FA ° Δ relative to a 0° twist club head in the lower toe quadrant and lower heel quadrant is less than −0.6°, less than −0.7, less than −0.8, or less than −0.9. In some embodiments, the FA ° Δ relative to a 0° twist club head in the lower toe quadrant and lower heel quadrant is between −0.6° to −1.2°, −0.7° to −1.1°, or −0.8° to −1°.
Table 4 shows that average LA ° Δ in Example 5 for the upper toe quadrant and lower toe quadrant are more lofted (more positive) than the 0° twist golf club head by more than 0.2°, more than 0.3°, more than 0.4°, more than 0.5°, or more than 0.6°. In some embodiments, the upper toe quadrant and lower toe quadrant have a LA ° Δ between 0.2° to 1°, between 0.3° to 0.9°, between 0.4° to 0.8°, or between 0.5° to 0.7° more lofted. The average LA ° Δ of the upper heel quadrant and lower heel quadrant of Example 5 relative to a 0° twist club head are less lofted (more negative) than the 0° twist golf club head by less than −0.2° less than −0.3°, less than −0.4°, less than −0.5°, or less than −0.6°. In some embodiments, the upper heel quadrant and lower heel quadrant have a LA ° Δ between −0.2° to −1°, between −0.3° to −0.9°, between −0.4° to −0.8°, or between −0.5° to −0.7° less lofted. The lower toe quadrant and upper toe quadrant of Example 5 are more lofted (more positive) than the 0° twist golf club head by more than 0.1° or between 0° to 1.5° more lofted. The lower heel quadrant and upper heel quadrant of Example 5 are less lofted (more negative) than the 0° twist golf club head by less than −0.1° or between 0° to −1° less lofted.
Table 4 shows that average LA ° Δ in Example 6 for the upper toe quadrant and lower toe quadrant are more lofted (more positive) than the 0° twist golf club head by more than 0.5°, more than 0.6°, more than 0.7°, more than 0.8°, or more than 0.9°. In some embodiments, the upper toe quadrant and lower toe quadrant have a LA ° Δ between 0.5° to 2.5°, between 0.6° to 2°, between 0.7° to 1.8°, or between 0.9° to 1.5° more lofted. The average LA ° Δ of the upper heel quadrant and lower heel quadrant of Example 6 is less lofted (more negative) than the 0° twist golf club head by less than-0.5° less than −0.6°, less than −0.7°, less than −0.8°, or less than −0.9°. In some embodiments, the upper heel quadrant and lower heel quadrant have an average LA ° Δ relative to 0° twist club head of between −0.5° to −2.5°, between −0.6° to −2°, between −0.7° to −1.8°, or between −0.9° to −1.5° less lofted. The lower toe quadrant and upper toe quadrant of Example 6 are more lofted (more positive) than the 0° twist golf club head by more than 0.1° or between 0° to 2.5° more lofted. The lower heel quadrant and upper heel quadrant of Example 6 are less lofted (more negative) than the 0° twist golf club head by less than −0.1° or between 0° to −2.5° less lofted.
Therefore, Examples 5 and 6 show a golf club head having four quadrants where the FA ° Δ is more open (more positive) in the upper heel and toe quadrants and more closed (more negative) in the lower heel and toe quadrants. Examples 5 and 6 also show a golf club head having four quadrants where the LA ° Δ is more lofted (more positive) in the upper toe quadrant and lower toe quadrant while being less lofted (more negative) in the upper heel quadrant and lower heel quadrant when compared to a 0° twist golf club head.
y=0.0333x (Eq. 1) Example 5
y=0.0667x (Eq. 2) Example 6
Equation 1 illustrates that for every 1 mm in movement along the y-axis 800, there is a relative FA ° Δ of 0.0333° for a “1° twist” golf club head. Equation 2 shows that for every 1 mm in movement along the y-axis 800, there is a corresponding relative FA ° Δ of 0.0667° for a “2° twist” golf club head. The slope of the equation describes the rate of change of the FA ° Δ relative to the measurement point as it is moved along the y-axis 800. Therefore, the rate of change can be represented as a x/mm where x is the FA ° Δ (in units of ° Δ).
In some embodiments, the FA ° Δ to y-axis rate of change is greater than zero, greater than 0.01° Δ/mm, greater than 0.02° Δ/mm, greater than 0.03° Δ/mm, greater than 0.04° Δ/mm, greater than 0.05° Δ/mm, or greater than 0.6° Δ/mm. In some embodiments, the FA ° Δ to y-axis rate of change is between 0.005° Δ/mm and 0.2° Δ/mm, between 0.01° Δ/mm and 0.1° Δ/mm, between 0.02° Δ/mm and 0.09° Δ/mm, or between 0.03° Δ/mm and 0.08° Δ/mm.
The LA ° Δ for Example 5 and 6 have a trend line defined as:
y=−0.0333x (Eq. 3) Example 5
y=−0.0667x (Eq. 4) Example 6
Equation 3 illustrates that for every 1 mm in movement along the x-axis 802, there is a relative LA ° Δ of −0.0333° for a “1° twist” golf club head. Equation 2 shows that for every 1 mm in movement along the x-axis 802, there is a corresponding relative LA ° Δ of −0.0667° for a “2° twist” golf club head. The rate of change for the LA ° Δ is negative for every positive movement along the x-axis 802.
In some embodiments, the LA ° Δ to x-axis rate of change is less than zero for every millimeter, less than −0.01° Δ/mm, less than −0.02° Δ/mm, less than −0.03° Δ/mm, less than −0.04° Δ/mm, less than −0.05° Δ/mm, or less than −0.06° Δ/mm.
In some embodiments, the LA ° Δ to x-axis rate of change is between −0.005° Δ/mm and −0.2° Δ/mm, between −0.01° Δ/mm and −0.1° Δ/mm, between −0.02° Δ/mm and −0.09° Δ/mm, or between −0.03° Δ/mm and −0.08° Δ/mm.
Table 5 shows the same embodiments of Table 3 but provides the difference in LA ° Δ and FA ° Δ when compared to the golf club head with “0° twist” as the base comparison. Example 5 has up to about +/−1° of LA ° Δ or up to about +/−0.7 FA ° Δ when compared to the golf club head with “0° twist”. Example 6 has up to about +/−2° of LA ° Δ and up to +/−1.4 FA ° Δ when compared to the golf club head with “0° twist”.
In Examples 5 and 6, the LA ° Δ and FA ° Δ relative to center face remains unchanged at the center face location (0 mm, 0 mm) when compared to the “0° twist” head. However, all other points away from the center face location in Examples 5 and 6 also have some non-zero amount of change in either LA ° Δ or FA ° Δ.
The numbers provided in the Tables above show loft angle change or face angle change relative to center face location or relative to a key point within a band. However, the actual nominal face angle or loft angle can be calculated quantitatively for a desired point using the below equation:
In Eq. 5 and Eq. 6 above, the variables are defined as:
Roll=Roll Radius (mm)
Bulge=Bulge Radius (mm)
LA=Nominal Loft Angle (°) at a desired point
FA=Nominal Face Angle (°) at a desired point
CFLA=Center Face Loft Angle (°)
CFFA=Center Face Face Angle (°)
YLOC=y-coordinate location on the y-axis of the predetermined point (mm)
XLOC=x-coordinate location on the x-axis of the predetermined point (mm)
DEG=degree of twist in the club head being measured (°)
By way of example, assume a golf club having a 1° twist, CFLA of 9.2°, a CFFA of 0°, a bulge of 330.2 mm, and a roll of 279.4 mm is provided, similar to Example 5 described in Table 3. In order to calculate the LA ° Δ and FA ° Δ at critical point P4 located at an x-y coordinate of (0 mm, 15 mm), 0 mm is utilized as the XLOC value and 15 mm as the YLOC value. The DEG value is 1°. When these variables are entered into Equation 5 above, a LA value of 12.277° and a FA value of 0.500° is calculated for critical point P4.
The LA ° Δ is the nominal loft at the critical point P4 minus the center face loft. In this case, the CFLA is 9.2°. Therefore the LA ° Δ is 12.277° minus 9.2° which equals 3.077° as shown in Table 3 at the critical point P4 in Example 5.
Likewise, Equation 6 yields the FA value of 0.500°. The FA ° Δ is the nominal face angle, FA, at the critical point P4 minus the center face face angle. In this case, the CFFA is 0° (which is likely always the case). Therefore, the FA ° Δ at critical point P4 is 0.500° minus 0° which equals 0.500° as shown in Table 3.
Thus, the FA ° Δ and LA ° Δ can be calculated at any desired x-y coordinate by calculating the nominal FA and LA values in Equations 5 and 6 above utilizing the necessary variables.
It is also possible to use the above equation to set bounds on the desired face shape for a given head. For example, if a head has a bulge radius (Bulge), and roll radius (Roll), it is possible to define two bounding surfaces for the desired twisted face surface by specifying two different twist amounts (DEG). In order to bound the example above, we can use a CFLA of 9.2°, a bulge of 330.2 mm, and a roll of 279.4 mm, then specify a range of twist of, for example 0.5°<DEG<1.5°. Then, preferably at least 50% of the face surface would have a FA and LA within the bounds of the equations using DEG=0.5° and DEG=1.5°. More preferably at least 70% of the face surface would have a FA and LA within the bounds of the equations using DEG=0.5° and DEG=1.5°. Most preferably at least 90% of the face surface would have a FA and LA within the bounds of the equations using DEG=0.5° and DEG=1.5°.
Similarly, if the target twist is, DEG=2.0°, then the upper/lower limits could be 1.5°<DEG<2.5°, and preferably 50%, or more preferably 70%, or most preferably 90% of the face surface would have a FA and LA within the bounds of the equations using those angles.
To make the upper/lower bound FA and LA equations more general for any driver with any bulge and roll, the process would be to define the amount of twist (i.e., 1°, 2°, 3°, etc.), then determine the desired CFLA, CFFA, Bulge and Roll, then define the upper bound equation using those parameters and a twist, DEG+, which is 0.5° higher than the target twist, DEG, and a lower bound with a twist, DEG−, which is 0.5° lower than the target twist, DEG. In this way, preferably 50%, or more preferably 70%, or most preferably 90% of the face surface would have a FA and LA within the bounds of the equations using DEG+ and DEG− and the desired CFLA, CFFA, Bulge and Roll.
For example, the range of CFLA can be between 7.5° and 16.0°, preferably 10.0°, the range of CFFA can be between −3.0° and +3.0°, preferably 0.0°, the range of Bulge can be between 228.6 mm to 457.2 mm, preferably 330.2 mm, and the range of Roll can be between 228.6 mm to 457.2 mm, preferably 279.4 mm. Any combination of these parameters within these ranges can be used to define the nominal FA and LA values over the face surface, and ranges of twist can range from 0.5° to 4.0°, preferably 1.0°.
Although the embodiments above describe a twisted face that has a generally open (more positive) FA ° Δ in the upper toe and heel quadrant, it is also possible to create a golf club head with a closed (more negative) FA ° Δ in the upper toe and heel quadrants. In other words, the twisting direction could be in the opposite direction of the embodiments described herein.
Because the twisted face described herein has a generally more open (more positive) face angle, the topline 280, shown in
In contrast, it is possible to have a golf club with a more negative or closed face twist in which case the topline 280 will have a more closed or negative face angle appearance to the golfer when the paint line occurs at the topline 280 of the face and crown intersection.
Various representative embodiments of iron type golf club heads will now be described. Typically, iron type golf club heads include a head body and a striking plate. The head body includes a heel portion, a toe portion, a topline portion, a sole portion, and a hosel configured to attach the club head to a shaft. In various embodiments, the head body defines a front opening configured to receive the striking plate at a front rim formed around a periphery of the front opening. In various embodiments, the striking plate is formed integrally (such as by casting) with the head body.
Various embodiments and aspects will be described with reference to details discussed below, and the accompanying drawings will illustrate the various embodiments. The following description and drawings are illustrative and are not to be construed as limiting on the scope of the disclosure. Numerous specific details are described to provide a thorough understanding of various embodiments of the present disclosure. However, in certain instances, well-known or conventional details are not described in order to provide a concise discussion of the various embodiments described herein.
1. Iron Type Golf Club Heads
A lower tangent point 990 on the outer surface of the club head 900 of a line 991 forming a 45° angle relative to the ground plane 911 defines a demarcation boundary between the sole portion 908 and the toe portion 904. Similarly, an upper tangent point 992 on the outer surface of the club head 900 of a line 993 forming a 45° angle relative to the ground plane 911 defines a demarcation boundary between the top line portion 906 and the toe portion 904. In other words, the portion of the club head that is above and to the left (as viewed in
In certain embodiments, a desirable CG-y location is between about 0.25 mm to about 20 mm along the CG y-axis 907 toward the rear portion of the club head. Additionally, a desirable CG-z location is between about 12 mm to about 25 mm along the CG z-up axis 909, as previously described.
The golf club head may be of solid (also referred to as “blades” and/or “musclebacks”), hollow, cavity back, or other construction.
In the embodiments shown in
In reference to
In certain embodiments of iron type golf club heads having hollow construction, such as the embodiment shown in
In some embodiments, the volume of the hollow iron club head 900 may be between about 10 cubic centimeters (cc) and about 120 cc. For example, in some embodiments, the hollow iron club head 900 may have a volume between about 20 cc and about 110 cc, such as between about 30 cc and about 100 cc, such as between about 40 cc and about 90 cc, such as between about 50 cc and about 80 cc, or such as between about 60 cc and about 80 cc. In some embodiments, the club head 900 may have a volume less than about 110 cc. In addition, in some embodiments, the hollow iron club head 900 has a club head depth, DCH, that is between about 15 mm and about 100 mm. For example, in some embodiments, the hollow iron club head 900 may have a club head depth, DCH, of between about 20 mm and about 90 mm, such as between about 30 mm and about 80 mm, such as between about 40 mm and about 70 mm, or such as between about 30 mm and 50 mm. In particular embodiments, the club head depth DCH may be between about 10 mm and about 50 mm.
In certain embodiments of the golf club head 900 that include a separate striking plate attached to the body 913 of the golf club head, the striking plate can be formed of forged maraging steel, maraging stainless steel, or precipitation-hardened (PH) stainless steel. In general, maraging steels have high strength, toughness, and malleability. Being low in carbon, they derive their strength from precipitation of inter-metallic substances other than carbon. The principle alloying element is nickel (15% to nearly 30%). Other alloying elements producing inter-metallic precipitates in these steels include cobalt, molybdenum, and titanium. In one embodiment, the maraging steel contains 18% nickel. Maraging stainless steels have less nickel than maraging steels but include significant chromium to inhibit rust. The chromium augments hardenability despite the reduced nickel content, which ensures the steel can transform to martensite when appropriately heat-treated. In another embodiment, a maraging stainless steel C455 is utilized as the striking plate. In other embodiments, the striking plate is a precipitation hardened stainless steel such as 17-4, 15-5, or 17-7.
The striking plate can be forged by hot press forging using any of the described materials in a progressive series of dies. After forging, the striking plate is subjected to heat-treatment. For example, 17-4 PH stainless steel forgings are heat treated by 1040° C. for 90 minutes and then solution quenched. In another example, C455 or C450 stainless steel forgings are solution heat-treated at 830° C. for 90 minutes and then quenched.
In some embodiments, the body 913 of the golf club head is made from 17-4 steel. However another material such as carbon steel (e.g., 1020, 1030, 8620, or 1040 carbon steel), chrome-molybdenum steel (e.g., 4140 Cr—Mo steel), Ni—Cr—Mo steel (e.g., 8620 Ni—Cr—Mo steel), austenitic stainless steel (e.g., 304, N50, or N60 stainless steel (e.g., 410 stainless steel) can be used.
In addition to those noted above, some examples of metals and metal alloys that can be used to form the components of the parts described include, without limitation: titanium alloys (e.g., 3-2.5, 6-4, SP700, 15-3-3-3, 10-2-3, or other alpha/near alpha, alpha-beta, and beta/near beta titanium alloys), aluminum/aluminum alloys (e.g., 3000 series alloys, 5000 series alloys, 6000 series alloys, such as 6061-T6, and 7000 series alloys, such as 7075), magnesium alloys, copper alloys, and nickel alloys.
In still other embodiments, the body 913 and/or striking plate of the golf club head are made from fiber-reinforced polymeric composite materials, and are not required to be homogeneous. Examples of composite materials and golf club components comprising composite materials are described in U.S. Patent Application Publication No. 2011/0275451, which is incorporated herein by reference in its entirety.
The body 913 of the golf club head can include various features such as weighting elements, cartridges, and/or inserts or applied bodies as used for CG placement, vibration control or damping, or acoustic control or damping. For example, U.S. Pat. No. 6,811,496, incorporated herein by reference in its entirety, discloses the attachment of mass altering pins or cartridge weighting elements.
After forming the striking plate and the body 913 of the golf club head, the striking plate 910 and body portion 913 contact surfaces can be finish-machined to ensure a good interface contact surface is provided prior to welding. In some embodiments, the contact surfaces are planar for ease of finish machining and engagement.
2. Iron Type Golf Club Heads Having a Flexible Boundary Structure
In some embodiments of the iron type golf club heads described herein, a flexible boundary structure (“FBS”) is provided at one or more locations on the club head. The flexible boundary structure may comprise, in several embodiments, at least one slot, at least one channel, at least one gap, at least one thinned or weakened region, and/or at least one other structure that enhances the capability of an adjacent or related portion of the golf club head to flex or deflect and to thereby provide a desired improvement in the performance of the golf club head. For example, in several embodiments, the flexible boundary structure is located proximate the striking face of the golf club head in order to enhance the deflection of the striking face upon impact with a golf ball during a golf swing. The enhanced deflection of the striking face may result, for example, in an increase or in a desired decrease in the coefficient of restitution (“COR”) of the golf club head. In other embodiments, the increased perimeter flexibility of the striking face may cause the striking face to deflect in a different location and/or different manner in comparison to the deflection that occurs upon striking a golf ball in the absence of the channel, slot, or other flexible boundary structure.
Turning to
The channel 1050 extends over a region of the sole 1008 generally parallel to and spaced rearwardly from the striking face plane 1025 (
Several aspects of the size, shape, and orientation of the club head 1000 and channel 1050 are illustrated in the embodiment shown in
Referring to
An imaginary line 1066 that connects the forward channel entry point 1064 and the rear channel entry point 1065 defines the channel opening 1058. A midpoint 1066a of the imaginary line 1066 is one of two points that define the channel centerline 1029. The other point defining the channel centerline 1029 is an upper channel peak 1067, which is defined as the midpoint of a curve having a local minimum radius (τmin, as measured from the exterior side 1049b of the schematic profile 1049) that is located between the forward wall exterior surface 1052a and the rear wall exterior surface 1054a. In an embodiment having one or more flat segment(s) or flat surface(s) located at the upper end of the channel between the forward wall 1052 and rear wall 1054, the upper channel peak 1067 is defined as the midpoint of the flat segment(s) or flat surface(s).
Another aspect of the size, shape, and orientation of the club head 1000 and channel 1050 is the sole width. For example, for each cross-section of the club head defined within the y-z plane, the sole width, D3, is the distance measured on the ground plane 1011 between the face plane projection point 1026 and a trailing edge projection point 1046. (See
Still another aspect of the size, shape, and orientation of the club head 1000 and channel 1050 is the channel to rear distance, D2. For example, for each cross-section of the club head defined within the y-z plane, the channel to rear distance D2 is the distance measured on the ground plane 1011 between the channel centerline projection point 1027 and a vertical projection of the trailing edge 1045 onto the ground plane 1011. (See
General Iron Information
Turning to
As mentioned above, the iron-type golf club head 1112 has the general configuration of a cavity back club head and, consequently, the rear surface 1126 includes a flange 1134 extending rearwardly around the periphery of the club head body 1114. The rearwardly extending flange 1134 defines a cavity 1136 within the rear surface 1126 of the club head body 1114. The flange 1134 includes a top flange 1138 extending rearwardly along the top line 1118 of the club head body 1114 adjacent the upper section 1128. The top flange 1138 extends the length of the top line 1118 from the heel portion 1122 of the club head body 1114 to the toe portion 1124 of the club head body 1114. The club head body 1114 is further provided with rearwardly extending flanges 1140, 1142 along the heel portion 1122 (that is, a heel flange 1140) and the toe portion 1124 (that is, a toe flange 1142) of the club head body 1114. These rearwardly extending flanges 1138, 1140, 1142 extend through the upper section 1128, lower section 1130 and middle section 1132 of the rear surface 26 of the iron-type golf club head 1112. Additionally, the club head body 1114 is provided with a bottom flange 1144 extending along the sole portion 1120 of the club head body 1114.
The iron-type golf club head 1112 is preferably cast from suitable metal such as stainless steel. Although shown as a cavity-back iron, the iron-type golf club head 1112 could be a “muscle back” or a “hollow” iron-type club and may be any iron-type club head from a one-iron to a wedge.
The iron type golf club head 1112 further includes a hosel 1146. The hosel 1146 has a hosel top edge 1146a, a hosel bore 1148, a hosel outer diameter top 1150, and a hosel outer diameter bottom 1152 (if the hosel is tapered). The hosel bore 1148 includes a proximal end 1148a and a distal end 1148b. The proximal end 1148a of the hosel bore 1148 is proximate the hosel top edge 1146a. Proximate the distal end 1148b of the hosel bore 1148 is a weight cartridge port or simply a cartridge port 1149 (See
The hosel bore 1148 ranges from about 8-12 mm, such as about 9.0 mm to about 9.6 mm. The hosel outer diameter top 1150 ranges from about 12-15 mm, such as about 13.0 mm to about 13.6 mm. The hosel outer diameter bottom 1152 ranges from about 12-17 mm, such as about 13.0 mm to about 13.6 mm.
The cartridge port 1149 allows for addition of a weight adjustment member (not shown) having a shape and size similar to the cartridge port 1149, which may optionally be used to adjust the swing weight of the iron type golf club. This may help with overcoming manufacturing tolerances or adjusting the iron type club to a player's preferred swing weight. The weight adjustment member may be formed of metal or plastic. Since the weight adjustment member is located near the center of gravity of the iron type club head 1112, the club head center of gravity will not change significantly when selecting any of the plurality of weight adjustment members.
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The hosel length 1170 is measured from the GPIP to hosel top edge 1146a along the hosel bore axis 1148c. A hosel bore length 1148d is measured from the hosel top edge 1146a along the hosel bore axis 1148c to the hosel bore distal end 1148b. For reference and as shown in
The base hosel length 1166 is measured parallel to the measurement surface from the hosel measurement datum 1176 to the distal end 1148b of the hosel bore 1148. The pin hosel length 1168 is measured parallel to the measurement surface 1178 from the hosel measurement datum 1176 to the hosel top edge 1146a. Generally, the hosel bore axis 1148c passes through the center of the hosel. The hosel bore axis can be found by inserting a cylindrically shaped pin or dowel having a diameter substantially similar to the hosel bore in the hosel bore. The axis of the pin or dowel should be substantially aligned with the hosel bore axis. If the hosel bore is tapered then the pin or dowel should have a substantially similar taper to determine the hosel bore axis. Another method of determining the hosel bore axis would be to measure the diameter of the hosel bore at two or more locations along the hosel bore and then construct an axis through the center points of the two or more diameters measured.
The base hosel length 1166 is at least 15 mm, such as at least 20 mm, such as at least 25 mm, such as at least 30 mm, or such as at least 35 mm. Typically in a lower lofted iron (e.g. 17 degrees to 48 degrees) the base hosel length may range from about 20 mm to about 30 mm. For wedges 50 degrees and greater, such as gap wedge, sand wedge, and lob wedge, the base hosel length is generally at least 40 mm.
The pin hosel length 1168 is at least 40 mm, such as at least 45 mm, such as at least 50 mm, such as at least 55 mm, such as at least 60 mm, such as at least 65 mm, such as at least 70 mm, or such as at least 75 mm. Although, this measurement may vary, generally the pin hosel length will be about 23 mm to about 33 mm greater than the base hosel length, or preferably about 25 mm to about 28 mm. Typically in a lower lofted iron e.g. 17 degrees to 48 degrees the pin hosel length may range from about 45 mm to about 60 mm, or preferably about 50 mm to about 60 mm. For wedges 50 degrees and greater, such as gap wedge, sand wedge, and lob wedge, the base hosel length is generally at least 40 mm.
The hosel length 1170 is at least 40 mm, such as at least 45 mm, such as at least 50 mm, such as at least 55 mm, such as at least 60 mm, such as at least 65 mm, such as at least 70 mm, such as at least 75 mm, such as at least 80 mm, such as at least 85 mm, such as at least 90 mm, or such as at least 95 mm.
The portion of the shaft that bonds to the hosel bore of the iron type golf club head is referred to as the bond length. In many instances, the bond length is the same as the hosel bore length 1148d, however in some instances there is a difference of about 1 mm to about 4 mm between the bond length and the hosel bore length. This is because a ferrule may be used that snaps into the hosel bore, which requires about 1 mm to about 4 mm for engagement. The bond length is generally about 20 mm to about 35 mm, preferably about 25 mm to about 30 mm. The bond length may also be approximated by finding the difference between the pin hosel length 1168 and the base hosel length 1166, which is typically between about 25 mm to about 30 mm.
Light Weight Iron-Type Hosel Construction
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The weight reducing designs generally have a hosel outside diameter ranging from about 11.6 mm to about 13.6 mm. Several of the designs selectively thin portions of the hosel resulting in a third outside diameter or a hosel outer diameter 51. Additionally, several of the designs offset the weight reducing feature from the hosel top edge 1146a by a hosel offset distance 83 ranging from about 1 mm to about 4 mm. The hosel bore 1148 diameter ranges from about 9.0 mm to about 9.6 mm. As a result, a hosel wall thickness 1184 ranges from of about 1.0 mm to about 2.3 mm. The hosel weight reduction zone 1182 extends from about 10 mm to about 30 mm. However, the hosel weight reduction zone 1182 pattern may extend further or less depending on the hosel length and desire to adjust the weight savings. For example, a club with a longer hosel length, such as a sand wedge, the pattern may extend about 20 mm to about 50 mm.
As shown in
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In the design shown in
The flute design selectively reduces the hosel wall thickness by varying the outer hosel wall diameter. The outer hosel wall diameter ranges from about 11.6 mm to about 13.6 mm. The flute design like the honeycomb design is offset from hosel top edge 1146a by about 2 mm to about 4 mm. The hosel bore diameter ranges from about 9.0 mm to about 9.6 mm resulting in a hosel wall thickness ranging from about 1.0 mm to about 2.3 mm. The flute pattern may have a length along the longitudinal axis of the hosel ranging from about 10 mm to about 30 mm. The pattern may extend further or less along the longitudinal axis of the hosel to adjust the weight savings. For example, a club with a longer hosel length, such as a sand wedge, the pattern may extend about 20 mm to about 50 mm.
The flute design may be angled relative to longitudinal axis of the hosel or it may be aligned with the longitudinal axis of the hose. The flute widths and flute heights may all be the same or vary along the hosel depending on the desired weight savings. The flute width is the horizontal distance measured from a first flute edge to a second flute edge, and the flute width is at least 1 mm and may range from about 1 mm to about 20 mm, preferably about 3 mm to about 5 mm. The flute length is the vertical distance measured from a top of the flute to a bottom of the flute, and the flute length is at least 4 mm and may range from about 5 mm to about 50 mm, such as about 10 mm to about 35 mm, or such as about 15 mm to about 25 mm. Alternatively, a pattern of flutes having smaller flute lengths may be used instead of long flutes. For example, two or more flutes may be stacked on top of one another to create a flute pattern similar to the honeycomb pattern discussed above.
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In the design shown in
The thru-slot design selectively reduces the hosel wall thickness around the perimeter of the hosel. As shown in
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The slot design selectively reduces the hosel wall thickness by varying the outer hosel wall diameter. The outer hosel wall diameter ranges from about 11.6 mm to about 13.6 mm. The slot design like the honeycomb design is offset from hosel top edge 1146a by about 2 mm to about 4 mm. The hosel bore diameter ranges from about 9.0 mm to about 9.6 mm resulting in a hosel wall thickness ranging from about 1.0 mm to about 2.3 mm. The slot pattern may have a length along the longitudinal axis of the hosel ranging from about 10 mm to about 30 mm. The pattern may extend further or less along the longitudinal axis of the hosel to adjust the weight savings. For example, for a club with a longer hosel length, such as a sand wedge, the pattern may extend about 20 mm to about 50 mm.
The slot design may be angled relative to longitudinal axis of the hosel or it may be aligned with the longitudinal axis of the hose. Additionally, each slot has a slot width and a slot length. The slot widths and slot lengths may all be the same or vary along the hosel depending on weight savings. The slot width is the horizontal distance measured from a first slot edge to a second slot edge, and the slot width is at least 1 mm and may range from about 1 mm to about 8 mm, preferably about 3 mm to about 5 mm. The slot length is the vertical distance measured from a top of the slot to a bottom of the slot, and the slot length is at least 5 mm and may range from about 5 mm to about 50 mm, such as about 10 mm to about 35 mm, such as about 15 mm to about 25 mm. Alternatively, a pattern of slots having smaller slot heights or widths may be used instead of long slots. For example, two or more slots may be stacked on top of one another to create a slot pattern.
For each of the above designs, by increasing the depth, width, and/or length of the weight reducing features even more mass savings may be had due to more material being removed. However, it is most beneficial to remove material that is furthest away from the club head CG because this has the most substantial effect on shifting Z-up downward. As discussed above, a lower Z-up promotes a higher launch and allows for increased ball speed depending on impact location.
By using the weight reducing features discussed above, a mass of at least 2 g to at least 4 g may be removed from the hosel and positioned elsewhere on the club to promote better ball speed. For a club that does not include the weight reducing features discussed above the mass of the hosel in the bond length region is about 12.7 g to about 13.0 g. Where the bond length region is about 25.4 mm plus about 2.5 mm of offset from the hosel top edge, or about 28 mm. By employing the weight reducing features, a traditional length hosel can be maintained while reducing the overall mass of the hosel. Over approximately 28 mm of hosel length the hosel mass can be reduced to less than about 11.0 g, such as less than about 10.5 g, such as less than about 10.0 g, such as less than about 9.5 g, such as less than about 9.0 g, such as less than about 8.7 g.
Similarly, by employing the weight reducing features the mass per unit length of the hosel can be reduced compared to a club without the weight reducing features. A club without the weight reducing features discussed above has a mass per unit length of about 0.454 g/mm, whereas a club employing the weight reducing features discussed above has a mass per unit length of less than about 0.40 g/mm, such as less than about 0.35 g/mm, such as less than about 0.30 g/mm, or such as less than about 0.26 g/mm. The weight reducing features may be applied over a hosel length of at least 10 mm, such as at least 15 mm, at least 20 mm, at least 25 mm, at least 30 mm, at least 35 mm, or at least 40 mm.
As discussed above, the iron type golf club head has a certain CG location. The CG location can be measured relative to the x, y, and z-axes. An additional measurement may be taken referred to as Z-up. The Z-up measurement is the vertical distance to the club head CG taken relative to the ground plane when the club head is soled and in the normal address position. It is important to understand that the hosel is a large chunk of mass that greatly impacts the CG location of the club head. Accordingly, removing mass from the hosel and repositioning the mass at or below the CG, such as, the sole of the club, can significantly impact the CG location of the club head. For example, by employing the weight reducing features, the Z-up shifted downward at least 0.5 mm and in some instances at least 1.5 mm. This Z-up shift was accomplished while maintaining a traditional hosel length and hosel diameter.
Light Weight Topline Construction
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Each of weight reducing designs maintains a “traditional” face height for maintain a traditional profile while offering a savings from about 2 g to about 18 g in the topline weight reduction zone 1191, and provides a downward CG-Z shift of at least 0.4 mm to at least 2.0 mm. This large downward CG-Z shift is the result of mass being removed from locations away from the club head CG and repositioned to a position at or below the club head CG, such as, for example, the sole of the club. Furthermore, the additional structural material removed from the hosel can be relocated to another location on the club, such as the toe portion of the club, to provide a lower center of gravity, increased moments of inertia, or other properties that result in enhanced ball striking performance for the club head.
The weight reducing designs generally have a topline thickness ranging from about 3 mm to about 12 mm. Several of the designs selectively thin portions of the topline resulting in a thinner topline. As a result, a topline wall thickness ranges from of about 1.0 mm to about 8 mm. The topline weight reduction zone 1191 extends from about 10 mm to about 80 mm. However, the topline weight reduction zone 91 may extend further or less depending on the face length and desire to adjust the weight savings. For example, a club with a longer face length may have a larger weight reduction zone.
As shown, in
The plastic material may be made from any suitable plastic including structural plastics. For the designs shown, the parts were modeled using Nylon-66 having a density of 1.3 g/cc, and a modulus of 3500 megapascals. However, other plastics may be perfectly suitable and may obtain better results. For example, a polyamide resin may be used with or without fiber reinforcement. For example, a polyamide resin may be used that includes at least 35% fiber reinforcement with long-glass fibers having a length of at least 10 millimeters premolding and produce a finished plastic topline having fiber lengths of at least 3 millimeters. Other embodiments may include fiber reinforcement having short-glass fibers with a length of at least 0.5-2.0 millimeters pre-molding. Incorporation of the fiber reinforcement increases the tensile strength of the primary portion, however it may also reduce the primary portion elongation to break therefore a careful balance must be struck to maintain sufficient elongation. Therefore, one embodiment includes 35-55% long fiber reinforcement, while an even further embodiment has 40-50% long fiber reinforcement.
One specific example is a long-glass fiber reinforced polyamide 66 compound with 40% carbon fiber reinforcement, such as the XuanWu 5 XW5801 resin having a tensile strength of 245 megapascal and 7% elongation at break. Long fiber reinforced polyamides, and the resulting melt properties, produce a more isotropic material than that of short fiber reinforced polyamides, primarily due to the three dimensional network formed by the long fibers developed during injection molding.
Another advantage of long-fiber material is the almost linear behavior through to fracture resulting in less deformation at higher stresses. In one particular embodiment the plastic topline is formed of a polycaprolactam, a polyhexamethylene adipinamide, or a copolymer of hexamethylene diamine adipic acid and caprolactam. However, other embodiments may include polypropylene (PP), nylon 6 (polyamide 6), polybutylene terephthalates (PBT), thermoplastic polyurethane (TPU), PC/ABS alloy, PPS, PEEK, and semi-crystalline engineering resin systems that meet the claimed mechanical properties.
In another embodiment the plastic topline is injection molded and is formed of a material having a high melt flow rate, namely a melt flow rate (275°/2.16 Kg), per ASTM D1238, of at least 10 g/10 min. A further embodiment is formed of a non-metallic material having a density of less than 1.75 grams per cubic centimeter and a tensile strength of at least 200 megapascal; while another embodiment has a density of less than 1.50 grams per cubic centimeter and a tensile strength of at least 250 megapascal.
Although, the mass savings and Zup shift is impressive for these two designs, the frequency far below 3000 Hz is unacceptable for most golfers, and the frequency duration is borderline acceptable. For comparison, the baseline club without any weight reduction done to the topline has a first mode frequency of 3213 Hz and a frequency duration of 4.4 ms. Accordingly the next several designs focus on improving the frequency while still achieving a modest weight savings and Zup shift. The frequency of these designs would likely be improved if weight reduction was targeted to only zone 1156a, or zones 1156a and 1156c.
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As already discussed above, instead of reducing weight across the entire topline weight reduction zone 1191, a more targeted approach that targets different zones, such as, for example, the first zone 1156a, the second zone 1156b, and the third zone 1156c, may be a better approach to balancing mass reduction and acoustic performance. As already discussed, removing material from the first zone 1156a allows for a greater impact on Zup, while removing material from the third zone 1156c allows for a greater impact to CG-x with only a minor impact to Z-up. Accordingly, if the goal is to shift Zup, then removing mass from the first zone 1156a is more modest approach that would provide better acoustic properties.
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The design shown in
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Each iron type golf club head design was modeled using commercially available computer aided modeling and meshing software, such as Pro/Engineer by Parametric Technology Corporation for modeling and Hypermesh by Altair Engineering for meshing. The golf club head designs were analyzed using finite element analysis (FEA) software, such as the finite element analysis features available with many commercially available computer aided design and modeling software programs, or stand-alone FEA software, such as the ABAQUS software suite by ABAQUS, Inc.
For each of the above designs, by increasing the depth, width, and/or length of the weight reducing features even more mass savings may be had due to more material being removed. However, it is most beneficial to remove material that is furthest away from the club head CG because this has the most substantial effect on shifting Z-up downward. As discussed above, a lower Z-up promotes a higher launch and allows for increased ball speed depending on impact location.
By using the weight reducing features discussed above, a mass of at least 2 g to at least 20 g may be removed from the hosel and positioned elsewhere on the club to promote better ball speed. By employing the weight reducing features the mass per unit length of the topline can be reduced compared to a club without the weight reducing features. Employing the weight reducing features over a topline length may yield a mass per unit length within the weight reduction zone of between about 0.09 g/mm to about 0.40 g/mm, such as between about 0.09 g/mm to about 0.35 g/mm, such as between about 0.09 g/mm to about 0.30 g/mm, such as between about 0.09 g/mm to about 0.25 g/mm, such as between about 0.09 g/mm to about 0.20 g/mm, or such as between about 0.09 g/mm to about 0.17 g/mm. In some embodiments, the topline weight reduction zone yields a mass per unit length within the weight reduction zone less than about 0.25 g/mm, such as less than about 0.20 g/mm, such as less than about 0.17 g/mm, such as less than about 0.15 g/mm, such as less than about 0.10 g/mm. The mass per unit length values given are for a topline made from a metallic material having a density between about 7,700 kg/m3 and about 8,100 kg/m3, e.g. steel. If a different density material is selected for the topline construction that could either increase or decrease the mass per unit length values. The weight reducing features may be applied over a topline length of at least 10 mm, such as at least 20 mm, such as at least 30 mm, such as at least 40 mm, such as at least 45 mm, such as at least 50 mm, such as at least 55 mm, or such as at least 60 mm.
As discussed above, the iron type golf club head has a certain CG location. The CG location can be measured relative to the x, y, and z-axis. An additional measurement may be taken referred to as Z-up. The Z-up measurement is the vertical distance to the club head CG taken relative to the ground plane when the club head is soled and in the normal address position. It is important to understand that the topline is a large chunk of mass that greatly impacts the CG location of the club head. Accordingly, removing mass from the topline and repositioning the mass at or below the CG, such as, the sole of the club, can significantly impact the CG location of the club head. For example, by employing the weight reducing features, the Z-up shifted downward at least 0.5 mm and in some instances at least 2 mm. This Z-up shift was accomplished while maintaining a traditional profile and traditional heel and toe face heights.
Adjustable Iron-Type Golf Club Construction
The hosel 1204 can include a shaft bore 1218 formed within the hosel 1204 that extends to a distal end portion 1220 of the shaft bore 1218. The shaft bore 1218 can have a generally cylindrical shape, and can have a central longitudinal axis 1222. The shaft bore 1218 can be configured to receive a distal end portion of the shaft, which can be secured in the shaft bore 1218 in various manners, such as with epoxy adhesive or glue. The hosel 1204 can also include a recess 1250, which can facilitate the securing of the shaft to the hosel 1204, for example, by allowing the use of a sealing ring (not pictured) in the recess 1250. In such a configuration, a central longitudinal axis of the shaft can be aligned with the central longitudinal axis 1222.
For purposes of this description, the “hosel” of a golf club head includes the portion of the club head which encloses the shaft bore and extends to within the region of the heel portion of the body. Thus, the hosel of the golf club heads described herein includes the adjustment bore, notch, openings, and other components described more fully below. Thus, the hosel of the golf club heads described herein includes what is sometimes referred to in the industry as a “hosel blend.” For purposes of this description, an “upper portion of the hosel” refers to the portion of the hosel which encloses the shaft bore.
The geometry of the golf club head 1200 can be adjusted and thus a golf club can be tailored to an individual golfer. That is, the geometry of the body 1202 and hosel 1204 of the golf club head 1200 can be adjusted based on a golfer's anatomy and/or golfing technique, in order to improve the reliability and/or quality of the golfer's shot. Generally, the geometry of the golf club head 1200 can be adjusted to help ensure that when a golfer swings a golf club, the striking face portion 1216 of the club head 1200 strikes a golf ball in a consistent and desired manner (e.g., in a way that minimizes “slice” and/or “hook,” as those terms are generally understood in the game of golf).
The terms “lie angle” and “loft angle” have well-understood meanings within the game of golf and the golf club industry. As used herein, these terms are intended to carry this conventional meaning. For purposes of illustration, the term “lie angle” can refer to an angle formed between the central longitudinal axis 1222 of the shaft bore 1218 and the ground when the sole portion 1212 of the golf club head 1200 rests on flat ground. For example, lie angle α is shown in
A first opening 1230 can be provided in the hosel 1204 which can connect a distal end portion of the adjustment bore 1226 and the notch 1228. A second opening 1232 can be provided in the hosel 1204 which can connect a distal end portion of the shaft bore 1218 with the notch 1228. As shown, the openings 1230 and 1232 can have diameters which are smaller than the diameters of the adjustment bore 1226 and the shaft bore 1218. In some embodiments, the openings 1230 and 1232 can be generally aligned with one another, and can have central longitudinal axes which are generally aligned with the central longitudinal axis 1222 of the shaft bore 1218. The opening 1232 can be provided with mechanical threads extending radially inward into the opening 1232.
In this configuration, the screw 1234 can be used as an actuator which can cause adjustment of the golf club head at the hinge to control geometric properties of the golf club head 1200. Specifically, in the illustrated embodiment, the screw 1234 can be used to modify the lie angle of the golf club head 1200. When the screw 1234 is tightened (e.g., threaded through the threads in the second opening 1232 toward the shaft bore 1218), the hosel 1204 bends at the living hinge 1240 such that the body 1202 of the club head 1200 rotates away from the hosel 1204 about the hinge 1240. Thus, when the screw 1234 is tightened, the topline portion 1214 and toe 1210 of the head 1200 rotate away from the hosel 1204 and the lie angle α decreases.
A retaining ring (not pictured) can be provided within the adjustment bore 1226 such that when the screw 1234 is loosened (e.g., threaded through the threads in the second opening 1232 away from the shaft bore 1218), the hosel 1204 bends at the living hinge 1240 such that the body 1202 of the club head 1200 rotates toward the hosel 1204 about the hinge 1240. Thus, when the screw 1234 is loosened, the topline portion 1214 and toe 1210 of the head 1202 rotate toward the hosel 1204 and the lie angle α increases. These features are described in more detail below.
A golf club can be fabricated, sold, and/or delivered with the golf club head 1200 in a neutral configuration. That is, the configuration in which it is anticipated that the fewest golfers will need to adjust the lie angle, or in which it is anticipated that the average amount by which golfers need to adjust the lie angle is minimized. This neutral configuration can be determined, for example, based on expert knowledge or empirical studies. The golf club head 1200 can be fabricated such that this neutral configuration is achieved by positioning the screw 1234 within the adjustment bore 1226 and tightening it to a predetermined degree, which can include not tightening it at all. When an individual golfer commences the process of adjusting, or “tuning,” the golf club, the screw can be further tightened to decrease the lie angle, or the screw can be loosened to increase the lie angle.
By fabricating and/or selling the golf club head 1200 in the neutral configuration, the number of golfers who adjust the club head 1200 can be decreased, and the degree to which many golfers adjust the golf club head 1200 can be reduced. This can help to reduce the stresses induced in the golf club head 1200 and/or reduce the potential for developing problems of fatigue in the hinge 1240. Further, a screw 1234 which has been tightened to a predetermined degree can carry a net tension force, which can increase frictional forces between the screw 1234 and the rest of the club head 1200. Increased frictional forces can in turn help to ensure that the screw 1234 is not unintentionally tightened, loosened, or removed from the openings 1230 and 1232, and the adjustment bore 1226.
It can be desirable to design the hinge 1240 to be relatively flexible so that it can be more easily bent by tightening or loosening the screw 1234. This can be accomplished by reducing the cross sectional area of the hinge 1240 or by forming the hinge 1240 from a relatively flexible material. The hinge 1240 can be made to be sufficiently flexible to allow adjustment while retaining sufficient strength to withstand stresses caused by using the club head 1200 to hit a golf ball. For example, striking a golf ball with the striking face portion 1216 of the club head 1200 can induce torque in the hosel 1204. Thus, the strength of the hinge 1240, in combination with the screw 1234 (which can provide additional strength) can be capable of resisting the torque experienced when the club head 1200 is used to hit a golf ball. That is, the screw can act as a secondary member which increases the rigidity of the golf club head in the region of the hinge. Further, the hinge 1240, in combination with the screw 1234, can be capable of resisting the stresses caused by repetitive use of the club head 1200 to strike golf balls, that is, they can be resistant to fatigue failure due to repetitive, cyclic stresses, for example, the stresses caused by hitting a golf ball several thousand times.
The features illustrated in
The lie angle of the golf club head 1200 can be adjusted simply by tightening or loosening a single screw 1234. For example, a golfer can adjust the lie angle α by hand or with a single hand tool (e.g., a screwdriver). This can allow repeatable, reversible, and/or rapid adjustment of the golf club head. This allows significant improvement over previous known methods in which a golf club head is plastically bent in a post manufacturing process. It also allows significant improvement over previously known systems which use an adjustable shaft attachment system, as these systems allow only incremental adjustment between predetermined, discrete angles, rather than continuous adjustment over a continuous range of angles, as in golf club head 1200.
As best shown in
In alternative embodiments, the alignment of the notch, screw, and hinge can be displaced angularly about the central longitudinal axis of the hosel bore from the alignment of the notch 1228, screw 1234, and hinge 1240 shown in
Golf club head 1300 can also include a screw bearing pad 1342. The bearing pad 1042 can be configured to support the screw head 1336 within the adjustment bore 1326, separating the screw head 1336 from the first opening 1330. The bearing pad 1342 can include a first hollow portion 1346 formed integrally with a second hollow portion 1348. The first hollow portion 1346 can be configured to avoid interference with the screw 1334 (that is, to allow the screw 1334 to pass through it without contacting it), and can be positioned adjacent to the first opening 1330. The second hollow portion 1348 can be configured for mating with the screw head 1336, in a way that facilitates some degree of lateral movement and/or rotation of the screw head 1336 relative to the bearing pad 1342, for example, as needed as the screw 1334 is loosened or tightened.
Thus, as best shown in
Further tightening of the screw 1334 through the threaded opening 1332 can thus cause the screw 1334 to pull the bearing pad 1342 generally toward the threaded opening 1332, thereby causing the golf club head 1300 to bend at the living hinge 1340. That is, tightening the screw 1334 can cause the topline portion 1314 and toe 1310 of the head 1300 to rotate away from the hosel 1302, thereby decreasing the lie angle γ (
The bearing pad 1342 can be formed integrally with the rest of the hosel 1304, or can be formed separately and coupled to the hosel 1304 after each has been independently formed. Thus, use of the bearing pad 1342 can allow the surface on which the screw head 1336 bears to be formed from a material different from that used to form the rest of the golf club head 1300. Use of the bearing pad 1342 can also allow the surface on which the screw head 1336 bears to be replaced periodically without a golfer needing to replace the entire golf club head 1300.
Golf club head 1300 can also include a retaining ring 1344. The retaining ring 1344 can be positioned within the adjustment bore 1326 and can serve to partially enclose the screw 1334 within the bore 1326. The retaining ring 1344 can include an opening (not pictured) through which a golfer or other person can reach the screw head 1336 and thereby tighten or loosen the screw 1334. The retaining ring 1344 can comprise an annular piece of material coupled to the hosel 1304 within the bore 1326. The retaining ring 1344 can in some cases prevent the screw 1334 from falling out of the adjustment bore 1326, and can provide a bearing surface configured for mating with the screw head 1336.
Loosening of the screw 1334 can cause it to come into contact with and bear against the retaining ring 1344. Further loosening of the screw 1334 through the threaded opening 1332 can thus cause the screw 1334 to push the retaining ring 1344 generally away from the threaded opening 1332, thereby causing the golf club head 1300 to bend at the living hinge 1340. That is, loosening the screw 1334 can cause the topline portion 1314 and toe 1310 of the head 1300 to rotate toward the hosel 1302, thereby increasing the lie angle γ of the golf club head 1300.
The retaining ring 1344 can be coupled to the hosel 1304 by casting, welding, bonding or any other method known in the art. Use of the retaining ring 1344 can allow the surface on which the screw head 1336 bears to be formed from a material different from that used to form the rest of the golf club head 1300. Use of the retaining ring 1344 can also allow the surface on which the screw head 1336 bears to be replaced periodically without a golfer needing to replace the entire golf club head 1300.
The golf club head 1400 can be bent about a living hinge 1440 by tightening or loosening the screw 1434 in a manner similar to that described with respect to golf club head 1400. Changes in angle θ (
W>0.5*D (Eq. 7)
W>0.5*(D+T) (Eq. 8)
W>T+(0.5*D) (Eq. 9)
The greater the distance W is, the less material is present in the living hinge 1440, and thus less force is required to adjust the golf club head 1400. In addition, the greater the distance W is, the longer the moment arm is between the screw 1434 and the hinge 1440, and thus less force is required to adjust the golf club head 1400.
In some embodiments, the hosel outer diameter D can be between about 12.3 mm and about 14.0 mm, or more specifically, between about 12.5 mm and 13.6 mm. The notch height H can be between 0.9 mm and 20.0 mm, between 0.9 mm and 15 mm, between 0.9 mm and 10 mm, between 0.9 mm and 5 mm, between 0.9 mm and 4 mm, between 0.9 mm and 3 mm, or between 0.9 mm and 2.5 mm. In some embodiments, the notch width W can be between 2.0 mm and 8.0 mm, between 3.0 mm and 6.0 mm, between 4.0 mm and 6.0 mm. In other embodiments, the notch width W can be greater than 6.25 mm, greater than 6.5 mm, greater than 6.75 mm, or greater than 7.00 mm. In some embodiments, the notch width W can be greater than half the hosel outer diameter D (W>0.5*D).
Spherical surfaces such as bearing surfaces 1456 and 1462 are especially advantageous because they can help to ensure proper loading of the bearing pad 1442 and retaining ring 1444 as the club head 1400 bends about hinge 1440. That is, regardless of the degree to which bending at the hinge 1440 causes the head of the screw 1434 to move with respect to the bearing pad 1442 or retaining ring 1444, the head of the screw 1434 will always have a complementary mating surface for bearing against either the bearing pad 1442 or the retaining ring 1444. For example, bearing pad 1442 and retaining ring 1444 can be desirable for use with embodiments of adjustable golf club heads in which both the lie angle and the loft angle are intended to be adjustable.
Cylindrical surfaces such as bearing surfaces 1502 and 1510 are advantageous in cases where movement of the head of the screw 1534 is confined to a single dimension. In such cases, the dimension along which the head of the screw 1434 is anticipated to move can be aligned with the cylindrical shape of the surfaces 1502 and 1510. In such a configuration, the head of the screw 1434 will always have a complementary mating surface for bearing against either the bearing pad 1500 or the retaining ring 1508. For example, bearing pad 1500 and retaining ring 1508 can be desirable for use with embodiments of adjustable golf club heads in which only the lie angle is intended to be adjustable, with the cylindrical shape of surfaces 1502 and 1510 being aligned with an axis extending through the notch, screw, and hinge of the adjustable golf club head.
In some embodiments, the bearing pad and/or the retaining ring of a golf club head can be provided with a conical, rather than cylindrical or spherical bearing or mating surface for mating with the head of an adjustment screw. Such a surface can provide a different profile for contacting the head of the screw than spherical or cylindrical surfaces can provide.
In one alternative embodiment, a golf club head can have a threaded first opening connecting the adjustment bore to the notch, and an unthreaded second opening connecting the shaft bore to the notch. In such an embodiment, the head of the screw can be positioned within the adjustment bore, and the screw can thread through the first opening, extend across the notch and through the second opening, and terminate at a relatively wide or expanded tip situated within the shaft bore. The shaft bore can have a retaining ring situated therein, thus trapping the expanded tip of the screw at the distal end portion of the shaft bore. Thus, in a manner similar to that described above, by turning the screw in the threads of the first opening, the tip of the screw can be caused to either pull on the distal end of the shaft bore or push against the retaining ring situated within the shaft bore, thereby causing adjustments in the geometry of the golf club head. In one specific implementation, a set screw can be used in this alternative embodiment, in which case the head of the screw can be flush with its shaft.
In some embodiments, a filler element or cap can be inserted into the notch, in order to fill or enclose the space therein. In some cases, the filler element can be non-functional. In some cases, the filler element can improve the aesthetic properties of the adjustable golf club head by providing a flush surface or in other ways. In some cases, the filler element can provide additional rigidity and/or strength to the golf club head. Filler elements can be compliant, one-size fits all components which can be used with a golf club head as it is adjusted, or can come in a set of varying sizes such that as the golf club head is adjusted, different filler elements can be used to cover the notch based on the degree to which the club head has been adjusted. Filler elements are desirably configured to not interfere with the adjustability of the golf club head, and in some cases can be easily removable and replaceable.
In some embodiments, a golf club head can include adjustment range limiters which can limit the range of angles through which the lie or loft angles of the club head can be adjusted. An adjustment range limiter can prevent the living hinge being bent beyond a predetermined range and can thus help to prevent damage to and reduce fatigue in the hinge. As one example, a solid piece of material secured within the shaft bore can help to prevent an adjustment screw being tightened beyond a predetermined level. As another example, an adjustment screw can be configured so that it is impossible to loosen it beyond a predetermined level, for example, because it will run out of the threads in the opening between the notch and the shaft bore. In one specific embodiment, a golf club head can be fabricated in a neutral configuration and can be configured such that its lie angle is adjustable through a range of 5° in either direction, i.e., through a total range of 10°.
In some embodiments, a golf club head can include visual indicators which can indicate to a golfer the level to which the screw is tightened and thus the level to which the lie angle of the club head has been adjusted. For example, tabs, notches, or other indicators can be provided on each of the screw head and the hosel, the relative positions of which can indicate each degree, or each half degree, or each quarter degree of adjustment of the lie angle of the golf club head. In some cases, tabs, notches, or other indicators can be provided on the screw head, which can indicate how far the screw head has been turned. In some cases, notches or other indicators can be provided on the shaft of the screw in order to indicate the distance the shaft of the screw has traveled relative to other components of the golf club head.
The screws described herein can be either right-handed or left-handed screws. That is, depending on the particular screw used, turning the head of the screw clockwise can either tighten or loosen the screw.
Adjustable golf club heads as described herein can be adjusted to improve a golfer's performance. For example, one method of adjusting a golf club head includes determining that a player's swing may benefit from an adjustment of the lie angle of one or more of their golf clubs, determining the amount of adjustment of the lie angle for the golf club to be adjusted, adjusting the golf club by turning a screw to cause the hosel to move toward or away from the club face, and ending the adjustment once the desired lie angle is obtained. In some cases, the adjustment can be ended when a visual indicator reveals that the desired lie angle has been achieved.
Various components of the golf club heads described herein can be formed from any of various appropriate materials. For example, components described herein can be formed from steel, titanium, or aluminum. Significant frictional forces can be developed between the surfaces of various components described herein as a golf club head is adjusted. Thus it can be advantageous if various components are fabricated from brass or other relatively lubricious materials, or if any of various surfaces are treated with any of various lubricants, including any of various wet or dry lubricants, with molybdenum disulfide being one exemplary lubricant. Frictional forces can help to ensure that the screw is not unintentionally tightened, loosened, or removed from the openings and the adjustment bore. Thus, various means can be used to advantageously increase frictional forces between various components. For example, chemical compounds or other thread locking components can be used for this purpose.
The components of the golf club heads described herein can be fabricated in any of various ways, as are known in the art of fabricating golf club heads. Features and advantages of any embodiment described herein can be combined with the features and advantages of any other embodiment described herein except where such combination is structurally impossible.
The hosel 1604 can further include a hosel weight reduction zone 1682. This design is similar to the flute design shown in
Similar to the discussion above, the design shown in
As shown, the flutes have a flute height 1686a and a flute width 1686b. As shown, there is a single row of flute features that encircle the hosel. More rows may be used, and the height 1686a and width 1686b may be varied. The flute height 1686a may range from about 2 mm to about 30 mm and the width 1686b may range from about 1 mm to about 42 mm. The flute pattern extends from about 10 mm to about 30 mm. However, the flute pattern may extend further or less depending on the hosel length and desire to adjust the weight savings.
The flute design selectively reduces the hosel wall thickness by varying the outer hosel wall diameter. The outer hosel wall diameter ranges from about 11.6 mm to about 13.6 mm. The flute design like the honeycomb design is offset from the hosel top edge by about 2 mm to about 4 mm. The hosel bore diameter ranges from about 9.0 mm to about 9.6 mm resulting in a hosel wall thickness ranging from about 1.0 mm to about 2.3 mm. The flute pattern may have a length along the longitudinal axis of the hosel ranging from about 10 mm to about 30 mm. The pattern may extend further or less along the longitudinal axis of the hosel to adjust the weight savings. For example, a club with a longer hosel length, such as a sand wedge, the pattern may extend about 20 mm to about 50 mm.
The flute design may be angled relative to longitudinal axis of the hosel or it may be aligned with the longitudinal axis of the hose. The flute widths and flute heights may all be the same or vary along the hosel depending on the desired weight savings. The flute width is the horizontal distance measured from a first flute edge to a second flute edge, and the flute width is at least 1 mm and may range from about 1 mm to about 20 mm, preferably about 3 mm to about 5 mm. The flute length is the vertical distance measured from a top of the flute to a bottom of the flute, and the flute length is at least 4 mm and may range from about 5 mm to about 50 mm, such as about 10 mm to about 35 mm, such as about 15 mm to about 25 mm. Alternatively, a pattern of flutes having smaller flute lengths may be used instead of long flutes. For example, two or more flutes may be stacked on top of one another to create a flute pattern similar to the honeycomb pattern discussed above.
As shown in
The iron-type golf club head 1602 further includes a bond length region of at least 10 mm and within the bond length region the hosel includes weight reducing features such that within the bond length region the hosel has a mass per unit length of less than about 0.45 g/mm. In other embodiments, the iron-type golf club head 1602 hosel has a mass per unit length within the bond length region between 0.45 g/mm and 0.40 g/mm, between 0.40 g/mm and 0.35 g/mm, between 0.35 g/mm and 0.30 g/mm, or between 0.30 g/mm and 0.26 g/mm within the bond length region. In some embodiments, the iron-type golf club head and/or the hosel has a density between about 7,700 kg/m3 and about 8,100 kg/m3.
The striking faces of any of the iron type golf clubs described above can comprise twisted striking surfaces having degrees of twist according to any of the embodiments described herein. For example, the plane of the striking surface can be twisted relative to a center face location such that the portion of the striking surface above a line extending through the center face location is twisted open with respect to an intended target (and optionally including increased loft), and the portion of the striking surface below the line is twisted closed with respect to the intended target (and optionally including decreased loft).
More particularly, the “twisted” horizontal and vertical striking face contours described above with reference to
In the illustrated embodiment, the toe-side vertical plane 1702, the center vertical plane 1704 (passing through center face location 1716), and the heel-side vertical plane 1706 extend from adjacent the topline portion 1718 to adjacent the sole portion 1720, and are separated by a distance of 14 mm as measured from the center face location 1716. The upper horizontal plane 1708, the center horizontal plane 1710 (passing through the center face 1716), and the lower horizontal plane 1712 extend from adjacent the toe portion 1722 to adjacent the heel portion 1724, and are spaced from each other by 15 mm as measured from the center face location 1716.
The vertical planes 1702, 1704, and 1706 can define striking face surface topline-to-sole contours A, B, and C extending from the topline portion 1718, similar to
For example,
The center face contour E, represented by a solid line, is defined by the intersection of the striking face surface and horizontal plane 1710 located at the center of the striking face 1714. The sole-side contour F, represented by a finely dashed line, is defined by the intersection of the striking face surface and the horizontal plane 1712 located on the lower side of the striking face 1714. The straight line toe-to-heel contours D, E, and F are considered three different horizontal contours across the striking face 1714 taken at three different locations to show the variability of the face angle across the face. The topline-side toe-to-heel contour D is more open (having a positive FA ° Δ, as defined above) when compared to the center face toe-to-heel contour E. The sole-side toe-to-heel contour F is more closed (having a negative FA ° Δ when measured relative to the center vertical plane).
For example,
With the type of “twisted” toe-to-heel and topline-to-sole contours defined above, a ball that is struck in the upper portion of the face will be influenced by horizontal contour D, which provides a general curvature that points to the right to counter the left tendency of a typical upper face shot, as described above. Likewise, the “twisted” toe-to-heel contour F can provide a general curvature that points to the left to counter the right tendency of a typical lower face shot. It is understood that the contours illustrated in
To further the understanding of what is meant by a “twisted face” on an iron-type golf club,
Because iron-type golf club heads typically do not have the bulge or roll radii associated with wood-type golf clubs, quantities such as FA ° Δ and/or LA ° Δ can be measured relative to the center face location directly, rather than along bands of bulge and/or roll curvature. For example,
As noted above, in certain embodiments the center face location 1716 can be empirically determined based on the location on the striking face 1714 where players most frequently strike a golf ball. Accordingly, in certain embodiments the center face location 1716 can be located at a z-axis coordinate of 20.5 mm above the ground plane 1752. The center face location 1716 can have an x-axis coordinate of 0 mm. In the illustrated embodiment, the center face location 1716 can be located at the midpoint of a scoreline 1750A. The scoreline 1750A can be a “center scoreline,” meaning that its length L (
In the illustrated embodiment, the center face location 1716 also falls within the scoreline 1750A.
Typically, scorelines such as the scoreline 1750A include curved or rounded edges 1756 and 1758 having radii r. Scorelines such as the scoreline 1750A may have a scoreline width W, defined as the distance across the groove 1760 of the scoreline from a point 1762 where the radiused edge 1756 begins to a point 1764 where the radiused edge 1758 ends. Thus, as used herein, a location or point that falls “within a scoreline” refers to a location or point that falls within the groove 1760 of the scoreline itself, and/or on either of the radiused edges 1756 and 1758 between the points 1762 and 1764.
Where a desired measurement point on a striking face falls “within the scoreline” as defined above, the desired measurement point may be moved or offset up or down along the striking face by a distance of W/2, and the measurement taken at that location. Alternatively, the desired measurement point may be offset along the striking face by a distance D/2, where D is the center-to-center distance between the groove of a scoreline into which a desired measurement point falls, and the groove of the next scoreline on the striking face above or below the desired measurement point. In yet other embodiments, where the radius r of the scoreline edges is known, the desired measurement point can be offset up or down along the striking face by an appropriate distance such that it no longer falls on a radiused scoreline edge. Any of these methods may be used to determine the center face location, and/or points on the face where FA ° Δ and/or LA ° Δ are to be measured.
In the illustrated embodiment, the critical points Q3 and Q6 can be located at (x, z) coordinates (0 mm, 15 mm) and (0 mm, −15 mm), respectively, and the total face angle change between these two critical locations Q3 and Q6 as an absolute value defines the amount of “twist” or “total twist” of the striking face, as described above. For example, a “1° twist” indicates that the Q3 point has a 0.5° twist relative to the center face location Q0, and the Q6 point has a −0.5° twist relative to the center face location Q0.
In the embodiment illustrated in
The iron-type golf club heads described herein may have any of the degrees of twist or twist ranges described herein, such as “0.2° twist”, “0.5° twist”, “0.6° twist”, “1° twist”, “1.5° twist”, “2° twist”, “3° twist”, “4° twist”, “5° twist”, “6° twist”, “8° twist”, etc. For a given amount of “twist,” the FA ° Δ is given by Equation 10 below, where Δz is the distance along the z-axis by which the measurement point is spaced from the center face location. The actual face angle at the measurement location is given by Equation 11.
For a given amount of “twist,” the LA ° Δ is given by Equation 12 below, which may be algebraically simplified to Equation 13.
The actual loft angle for a specified measurement location is given by Equation 14, where “static loft” is the nominal loft angle of the iron-type club when positioned on the ground at scoreline lie.
Thus, in certain embodiments the point Q3 may have a FA ° Δ, of from 0.09° (corresponding to a “0.2° twist”) to 4° (corresponding to an “8° twist”), and the point Q6 may have corresponding values of −0.09° to −4°. In certain embodiments the point Q3 may have a FA ° Δ, of from 0.25° (corresponding to a “0.5° twist”) to 3° (corresponding to a “6° twist”), and the point Q6 may have corresponding values of −0.25° to −3°. In certain embodiments, the point Q4 may have a LA ° Δ, of 0.09° (corresponding to a “0.2° twist”) to 3.75°, such as about 3.73° (corresponding to a “8° twist”), and the point Q8 may have corresponding values of −0.09° to −3.75°, such as about −3.73°. In certain embodiments, the point Q4 may have a LA ° Δ of 0.23° (corresponding to a “0.5° twist”) to 2.8° (corresponding to a “6° twist”), and the point Q8 may have corresponding LA ° Δ, values of −0.23° to −2.8°.
The iron-type golf clubs described herein may have any suitable loft angle. For example, iron-type golf clubs are typically provided in sets ranging from a 1-iron, a 2-iron, or a 3-iron to a 9-iron and/or a pitching wedge. In such sets, the lower-numbered clubs have lower loft angles than higher-numbered clubs in the set. For example, a 3-iron may have a loft angle of 17° to 22° or 18° to 21°. In particular embodiments, a 3-iron may have a loft angle of 19° or 20°. Meanwhile, a 9-iron can have a loft angle of 35° to 45°, or 38° to 42°. In particular embodiments, a 9-iron can have a loft angle of 40°, and a pitching wedge may have a loft angle of 45°.
In some embodiments, the amount of twist can be different for different irons in a set. For example, in certain embodiments each iron club may have a different amount of twist, with the lowest number iron having the highest amount of twist and the highest iron having the lowest amount of twist, or no twist. Table 8 below provides two representative examples. In Example 1, a 3-iron has 2.33° of twist, and the amount of twist of each successive club in the set decreases by 0.33°, and the wedge has 0° or no twist. In Example 2, the 3-iron and the 4-iron may both have 2.0° of twist. In yet other embodiments, the difference or increment in the amount of twist between successive clubs in a set may be 0.1°, 0.2°, 0.25°, 0.3°, 0.33°, 0.4°, 0.5°, 0.67°, 0.75°, 1.0°, 1.25°, 1.5°, 2.0°, etc.
In some embodiments, two or more clubs in a set may have the same degree of twist. In such sets, the clubs may be grouped according to the amount of twist applied. For example, in one representative example given in Table 9, the 3-iron, 4-iron, 5-iron, and/or 6-iron may have 2.0° of twist, the 7-iron and 8-iron may have 1.0° of twist, and the 9-iron and the wedge may have 0° of twist.
Table 10 below provides yet another example, in which the irons are grouped in sets of two clubs with a 0.5° increment in the amount of twist between groups. For example, the 3-iron and 4-iron have 2.0° of twist, the 5-iron and the 6-iron have 1.5° of twist, the 7-iron and the 8-iron have 1.0° of twist, and the 9-iron and the wedge may have 0.5° or 0° of twist. Any of the twist values and increments described herein may also be applied to other types of irons, such as “better player's” irons or “game improvement” irons, and/or driving irons.
Representative average FA ° Δ and LA ° Δ values for various quadrants of iron-type club heads similar to the club head 2000 of
Thus, in the example in Table 11 below in which the striking face 2004 has 2.0° of twist, the upper toe quadrant 2004 can have an average FA ° Δ of 1.1° relative to the center face location, the upper heel quadrant 2006 can have an average FA ° Δ of 0.70° relative to the center face location, the lower heel quadrant 2010 can have an average FA ° Δ of −0.75° relative to the center face location, and the lower toe quadrant 2008 can have an average FA ° Δ of −0.75° relative to the center face location.
Still referring to
In some embodiments, the average FA ° Δ of the upper toe quadrant 2004 can be from 0.275° (corresponding to a “0.5° twist”) to 4.4° (corresponding to a “8° twist”). In some embodiments, the average FA ° Δ of the upper toe quadrant 2004 can be from 0.275° to 3.3° (corresponding to a “6° twist”). In some embodiments, the average FA ° Δ of the upper toe quadrant 2004 can be from 0.275° to 2.2° (corresponding to a “4° twist”). In some embodiments, the average FA ° Δ of the upper toe quadrant 2004 can be from 0.275° to 1.1° (corresponding to a “2° twist”). In some embodiments, the average FA ° Δ of the upper toe quadrant 2004 can be from 0.275° to 0.55° (corresponding to a “1° twist”).
In some embodiments, the average LA ° Δ of the upper toe quadrant 2004 can be from 0.245° (corresponding to a “0.5° twist”) to about 4°, such as 3.92° (corresponding to an “8° twist”). In some embodiments, the average LA ° Δ of the upper toe quadrant 2004 can be from 0.245° to about 3°, such as 2.94° (corresponding to a “6° twist”). In some embodiments, the average LA ° Δ of the upper toe quadrant 2004 can be from 0.245° to about 2°, such as 1.96° (corresponding to a “4° twist”). In some embodiments, the average LA ° Δ of the upper toe quadrant 2004 can be from 0.245° to about 1°, such as 0.98° (corresponding to a “2° twist”). In some embodiments, the average LA ° Δ of the upper toe quadrant 2004 can be from 0.245° to about 0.5°, such as 0.49° (corresponding to a “1° twist”).
In certain embodiments, any of the club heads described herein can include striking face plates and/or club head bodies made from one or more cast or machined titanium alloys. Compared to titanium golf club faces formed for sheet machining or forging processes, cast faces can have the advantage of lower cost and complete freedom of design. However, golf club faces cast from conventional titanium alloys, such as 6-4 Ti, need to be chemically etched to remove the alpha case on one or both sides so that the faces are durable. Such etching requires application of hydrofluoric (HF) acid, a chemical etchant that is difficult to handle, extremely harmful to humans and other materials, an environmental contaminant, and expensive.
Faces or club bodies cast from titanium alloys comprising aluminum (e.g., 8.5-9.5% Al), vanadium (e.g., 0.9-1.3% V), and molybdenum (e.g., 0.8-1.1% Mo), optionally with other minor alloying elements and impurities, herein collectively referred to a “9-1-1 Ti”, can have less significant alpha case, which renders HF acid etching unnecessary or at least less necessary compared to faces or bodies made from conventional 6-4 Ti and other titanium alloys.
Further, 9-1-1 Ti can have minimum mechanical properties of 820 MPa yield strength, 958 MPa tensile strength, and 10.2% elongation. These minimum properties can be significantly superior to typical cast titanium alloys, such as 6-4 Ti, which can have minimum mechanical properties of 812 MPa yield strength, 936 MPa tensile strength, and ˜6% elongation.
Golf club heads, such as many types of irons, that are cast including the face as an integral part of the body (e.g., cast at the same time as a single cast object) can provide superior structural properties compared to club heads where the face is formed separately and later attached (e.g., welded or bolted) to a front opening in the club head body. However, the advantages of having an integrally cast Ti face are mitigated by the need to remove the alpha case on the surface of cast Ti faces.
With the herein disclosed club heads comprising an integrally cast 9-1-1 Ti face and body unit, the drawback of having to remove the alpha case can be eliminated, or at least substantially reduced. For a cast 9-1-1 Ti face, using a conventional mold pre-heat temperature of 1000 C or more, the thickness of the alpha case can be about 0.15 mm or less, or about 0.20 mm or less, or about 0.30 mm or less, such as between 0.10 mm and 0.30 mm in some embodiments, whereas for a cast 6-4 Ti face the thickness of the alpha case can be greater than 0.15 mm, or greater than 0.20 mm, or greater than 0.30 mm, such as from about 0.25 mm to about 0.30 mm in some examples.
Another titanium alloy that can be used to form any of the striking faces and/or club heads described herein can comprise titanium, aluminum, molybdenum, chromium, vanadium, and/or iron. For example, in one representative embodiment the alloy may be an alpha-beta titanium alloy comprising 6.5% to 10% Al by weight, 0.5% to 3.25% Mo by weight, 1.0% to 3.0% Cr by weight, 0.25% to 1.75% V by weight, and/or 0.25% to 1% Fe by weight, with the balance comprising Ti.
In another representative embodiment, the alloy may comprise 6.75% to 9.75% Al by weight, 0.75% to 3.25% or 2.75% Mo by weight, 1.0% to 3.0% Cr by weight, 0.25% to 1.75% V by weight, and/or 0.25% to 1% Fe by weight, with the balance comprising Ti.
In another representative embodiment, the alloy may comprise comprise 7% to 9% Al by weight, 1.75% to 3.25% Mo by weight, 1.25% to 2.75% Cr by weight, 0.5% to 1.5% V by weight, and/or 0.25% to 0.75% Fe by weight, with the balance comprising Ti.
In another representative embodiment, the alloy may comprise 7.5% to 8.5% Al by weight, 2.0% to 3.0% Mo by weight, 1.5% to 2.5% Cr by weight, 0.75% to 1.25% V by weight, and/or 0.375% to 0.625% Fe by weight, with the balance comprising Ti.
In another representative embodiment, the alloy may comprise 8% Al by weight, 2.5% Mo by weight, 2% Cr by weight, 1% V by weight, and/or 0.5% Fe by weight, with the balance comprising Ti. Such titanium alloys can have the formula Ti-8Al-2.5Mo-2Cr-1V-0.5Fe. As used herein, reference to “Ti-8Al-2.5Mo-2Cr-1V-0.5Fe” refers to a titanium alloy including the referenced elements in any of the proportions given above. Certain embodiments may also comprise trace quantities of K, Mn, and/or Zr, and/or various impurities.
Ti-8Al-2.5Mo-2Cr-1V-0.5Fe can have minimum mechanical properties of 1150 MPa yield strength, 1180 MPa ultimate tensile strength, and 8% elongation. These minimum properties can be significantly superior to other cast titanium alloys, including 6-4 Ti and 9-1-1 Ti, which can have the minimum mechanical properties noted above. In some embodiments, Ti-8Al-2.5Mo-2Cr-1V-0.5Fe can have a tensile strength of from about 1180 MPa to about 1460 MPa, a yield strength of from about 1150 MPa to about 1415 MPa, an elongation of from about 8% to about 12%, a modulus of elasticity of about 110 GPa, a density of about 4.45 g/cm3, and a hardness of about 43 on the Rockwell C scale (43 HRC). In particular embodiments, the Ti-8Al-2.5Mo-2Cr-1V-0.5Fe alloy can have a tensile strength of about 1320 MPa, a yield strength of about 1284 MPa, and an elongation of about 10%.
In some embodiments, striking faces can be cast from Ti-8Al-2.5Mo-2Cr-1V-0.5Fe, and/or stamped from Ti-8Al-2.5Mo-2Cr-1V-0.5Fe sheet stock. In some embodiments, striking surfaces and club head bodies can be integrally formed or cast together from Ti-8Al-2.5Mo-2Cr-1V-0.5Fe, depending upon the particular characteristics desired.
The mechanical parameters of Ti-8Al-2.5Mo-2Cr-1V-0.5Fe given above can provide surprisingly superior performance compared to other existing titanium alloys. For example, due to the relatively high tensile strength of Ti-8Al-2.5Mo-2Cr-1V-0.5Fe, cast and/or stamped sheet metal striking faces comprising this alloy can exhibit less deflection per unit thickness compared to other alloys when striking a golf ball. This can be especially beneficial for clubs configured for striking a ball at high speed, as the higher tensile strength of Ti-8Al-2.5Mo-2Cr-1V-0.5Fe results in less deflection of the striking face, and reduces the tendency of the striking face to flatten with repeated use. This allows the striking face to retain its original bulge, roll, and “twist” dimensions over prolonged use, including by advanced and/or professional golfers who tend to strike the ball at particularly high club velocities.
In some embodiments, any of the iron-type golf club heads described herein can be configured as cavity-backed, muscle-back, and/or hollow cavity iron-type gold club heads. An exemplary embodiment of an iron-type golf club head 2100 comprising an internal cavity 2142 that is partially or entirely filled with a filler material 2101 is shown in
In some implementations, the filler material 2101 is made from a non-metal, such as a thermoplastic material, thermoset material, and the like, in some implementations. In other implementations, the internal cavity 2142 is not filled with a filler material 2101, but rather maintains an open, vacant, cavity within the club head.
According to one embodiment, the filler material 2101 is initially a viscous material that is injected or otherwise inserted into the club head through an injection port 2107 located on the toe portion of the club head. The injection port 2107 can be located anywhere on the club head 2100 including the topline, sole, heel, or toe. Examples of materials that may be suitable for use as a filler material 2101 to be placed into a club head include, without limitation: viscoelastic elastomers; vinyl copolymers with or without inorganic fillers; polyvinyl acetate with or without mineral fillers such as barium sulfate; acrylics; polyesters; polyurethanes; polyethers; polyamides; polybutadienes; polystyrenes; polyisoprenes; polyethylenes; polyolefins; styrene/isoprene block copolymers; hydrogenated styrenic thermoplastic elastomers; metallized polyesters; metallized acrylics; epoxies; epoxy and graphite composites; natural and synthetic rubbers; piezoelectric ceramics; thermoset and thermoplastic rubbers; foamed polymers; ionomers; low-density fiber glass; bitumen; silicone; and mixtures thereof. The metallized polyesters and acrylics can comprise aluminum as the metal. Commercially available materials include resilient polymeric materials such as Scotchweld™ (e.g., DP105™) and Scotchdamp™ from 3M, Sorbothane™ from Sorbothane, Inc., DYAD™ and GP™ from Soundcoat Company Inc., Dynamat™ from Dynamat Control of North America, Inc., NoViFlex™ Sylomer™ from Pole Star Maritime Group, LLC, Isoplast™ from The Dow Chemical Company, Legetolex™ from Piqua Technologies, Inc., and Hybrar™ from the Kuraray Co., Ltd. In still other embodiments, the filler 2101 material may be placed into the club head 2100 and sealed in place with a plug 2105, or resilient cap or other structure formed of a metal, metal alloy, metallic, composite, hard plastic, resilient elastomeric, or other suitable material.
In one embodiment, the plug 2105 is a metallic plug that can be made from steel, aluminum, titanium, or a metallic alloy. In one embodiment, the plug 2105 is an anodized aluminum plug that is colored a red, green, blue, gray, white, orange, purple, black, clear, yellow, or metallic color. In one embodiment, the plug 2105 is a different or contrasting color from the majority color located on the club head body 2100.
In some embodiments, the filler material includes a slight recess or depression 2103 that accommodates the variable face thickness of the striking plate 2104. In other words, the recess or depression 2103 located in the filler material 2101 mates or is keyed with a thickened portion of the striking plate 2104. In one embodiment, the thickened portion of the striking plate 2104 occurs at the center of the striking plate 2104.
In one embodiment, the golf club head 2100 includes a recess 2109 that allows the weight 2196 to be located. Once the weight 2196 is positioned within the recess 2109 and the strike plate 2104 has been attached, the filler material 2101 is injected through the port 2107 and sealed with the plug 2105. In certain embodiments, the weight 2196 can be positioned below the center face location (e.g., closer to the ground plane than the center face location). Certain embodiments may comprise one or more weights such as weight 2196, such as two or more weights, three or more weights, etc., positioned below the center face location and located toward a toe-ward end of the golf club head.
In one embodiment, the filler material 2101 has a minor impact on the coefficient of restitution (herein “COR”) as measured according to the United States Golf Association (USGA) rules set forth in the Procedure for Measuring the Velocity Ratio of a Club Head for Conformance to Rule 4-1e, Appendix II Revision 2 Feb. 8, 1999, herein incorporated by reference in its entirety.
Table 12 below provides examples of the COR change relative to a calibration plate of multiple club heads of the construction shown in
Due to the slight variability between different calibration plates, the values described below are described in terms of a change in COR relative to a calibration plate base value. For example, if a calibration plate has a 0.831 COR value, Example 1 for an un-filled head has a COR value of −0.019 less than 0.831 which would give Example 1 (Unfilled) a COR value of 0.812. The change in COR for a given head relative to a calibration plate is accurate and highly repeatable.
Table 12 illustrates that before the filler material 2101 is introduced into the cavity 2142 of golf club head 2100, an Unfilled COR drop off relative to the calibration plate (or first COR drop off value) is between 0 and −0.05, between 0 and −0.03, between −0.00001 and −0.03, between −0.00001 and −0.025, between −0.00001 and −0.02, between −0.00001 and −0.015, between −0.00001 and −0.01, or between −0.00001 and −0.005.
In one embodiment, the average COR drop off or loss relative to the calibration plate for a plurality of Unfilled COR golf club head within a set of irons is between 0 and −0.05, between 0 and −0.03, between −0.00001 and −0.03, between −0.00001 and −0.025, between −0.00001 and −0.02, between −0.00001 and −0.015, or between −0.00001 and −0.01.
Table 12 further illustrates that after the filler material 2101 is introduced into the cavity 2142 of golf club head 2100, a Filled COR drop off relative to the calibration plate (or second COR drop off value) is more than the Unfilled COR drop off relative to the calibration plate. In other words, the addition of the filler material 2101 in the Filled COR golf club heads slows the ball speed (Vout—Velocity Out) after rebounding from the face by a small amount relative to the rebounding ball velocity of the Unfilled COR heads.
In some embodiments shown in Table 12, the COR drop off or loss relative to the calibration plate for a Filled COR golf club head is between 0 and −0.05, between 0 and −0.03, between −0.00001 and −0.03, between −0.00001 and −0.025, between −0.00001 and −0.02, between −0.00001 and −0.015, between −0.00001 and −0.01, or between −0.00001 and −0.005.
In one embodiment, the average COR drop off or loss relative to the calibration plate for a plurality of Filled COR golf club head within a set of irons is between 0 and −0.05, between 0 and −0.03, between −0.00001 and −0.03, between −0.00001 and −0.025, between −0.00001 and −0.02, between −0.00001 and −0.015, between −0.00001 and −0.01, or between −0.00001 and −0.005.
However, the amount of COR loss or drop off for a Filled COR head is minimized when compared to other constructions and filler materials. The last column of Table 12 illustrates a COR change between the Unfilled and Filled golf club heads which are calculated by subtracting the Unfilled COR from the Filled COR table columns. The change in COR (COR change value) between the Filled and Unfilled club heads is between 0 and −0.1, between 0 and −0.05, between 0 and −0.04, between 0 and −0.03, between 0 and −0.025, between 0 and −0.02, between 0 and −0.015, between 0 and −0.01, between 0 and −0.009, between 0 and −0.008, between 0 and −0.007, between 0 and −0.006, between 0 and −0.005, between 0 and −0.004, between 0 and −0.003, or between 0 and −0.002. Remarkably, one club head was able to achieve a change in COR of zero between a filled and unfilled golf club head. In other words, no change in COR between the Filled and Unfilled club head state. In some embodiments, the COR change value is greater than −0.1, greater than −0.05, greater than −0.04, greater than −0.03, greater than −0.02, greater than −0.01, greater than −0.009, greater than −0.008, greater than −0.007, greater than −0.006, greater than −0.005, greater than −0.004, or greater than −0.003.
In some embodiments, at least one, two, three or four iron golf clubs out of an iron golf club set has a change in COR between the Filled and Unfilled states of between 0 and −0.1, between 0 and −0.05, between 0 and −0.04, between 0 and −0.03, between 0 and −0.02, between 0 and −0.01, between 0 and −0.009, between 0 and −0.008, between 0 and −0.007, between 0 and −0.006, between 0 and −0.005, between 0 and −0.004, between 0 and −0.003, or between 0 and −0.002.
In yet other embodiments, at least one pair or two pair of iron golf clubs in the set have a change in COR between the Filled and Unfilled states of between 0 and −0.1, between 0 and −0.05, between 0 and −0.04, between 0 and −0.03, between 0 and −0.02, between 0 and −0.01, between 0 and −0.009, between 0 and −0.008, between 0 and −0.007, between 0 and −0.006, between 0 and −0.005, between 0 and −0.004, between 0 and −0.003, or between 0 and −0.002.
In other embodiments, an average of a plurality of iron golf clubs in the set has a change in COR between the Filled and Unfilled states of between 0 and −0.1, between 0 and −0.05, between 0 and −0.04, between 0 and −0.03, between 0 and −0.02, between 0 and −0.01, between 0 and −0.009, between 0 and −0.008, between 0 and −0.007, between 0 and −0.006, between 0 and −0.005, between 0 and −0.004, between 0 and −0.003, or between 0 and −0.002.
In some embodiments, the filler material 2101 is a two part polyurethane foam that is a thermoset and is flexible after it is cured. In one embodiment, the two part polyurethane foam is any methylene diphenyl diisocyanate (a class of polyurethane prepolymer) or silicone based flexible or rigid polyurethane foam.
Additional examples of cavity-backed, muscle-back, and hollow cavity iron-type gold club heads are described in U.S. Publication No. 2016/0193508, which is incorporated by reference herein. Additional examples of various foam-filled iron-type golf club heads and flexible boundary structures are described in greater detail in U.S. Publication No. 2018/0185717, U.S. Publication No. 2018/0185715, U.S. Pat. Nos. 8,088,025, 6,811,496, 8,535,177, and 8,932,150, which are all incorporated herein by reference.
For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, apparatuses, and systems should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods, apparatuses, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved.
As used herein, the terms “a”, “an” and “at least one” encompass one or more of the specified element. That is, if two of a particular element are present, one of these elements is also present and thus “an” element is present. The terms “a plurality of” and “plural” mean two or more of the specified element. As used herein, the term “and/or” used between the last two of a list of elements means any one or more of the listed elements. For example, the phrase “A, B, and/or C” means “A,” “B,” “C,” “A and B,” “A and C,” “B and C” or “A, B and C.” As used herein, the term “coupled” generally means physically coupled or linked and does not exclude the presence of intermediate elements between the coupled items absent specific contrary language.
In some examples, values, procedures, or apparatus may be referred to as “lowest,” “best,” “minimum,” or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many alternatives can be made, and such selections need not be better, smaller, or otherwise preferable to other selections.
In the description, certain terms may be used such as “up,” “down,” “upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” and the like. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships. But, these terms are not intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an “upper” surface can become a “lower” surface simply by turning the object over. Nevertheless, it is still the same object.
In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the disclosure. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of the disclosure as set forth. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.
This application claims the benefit of U.S. Provisional Application No. 62/687,143, filed on Jun. 19, 2018, which is incorporated herein by reference in its entirety. In addition to the incorporations discussed further herein, other patents and patent applications concerning golf clubs, such as U.S. application Ser. No. 15/811,430 and U.S. Pat. No. 9,814,944, are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62687143 | Jun 2018 | US |
