JP2012526634A - Golf assembly and golf club having aerodynamic characteristics and a club head of a specific shape - Google Patents

Abstract

The golf club head is located at the ball striking surface (17), crown (18), toe (20), heel (24), sole (28), back surface (22), and the intersection of the ball striking surface, heel, crown and sole. A body member having a hosel region (26). The body member can have a first cross section having a first airfoil surface in the heel. The first cross section may face approximately 90 degrees from the center line of the club head (XXIX). The body member can have a second cross section having a second airfoil surface. The second cross section may be oriented at about 45 (XXXI) degrees or about 70 (XXX) degrees. The airfoil surface can be defined by spline points or equations. A golf club including a golf club head is also provided.

Description

Related Applications This patent application is filed on May 13, 2009, entitled “Golf Club Assembly and Golf Club With Aerodynamic Features” and is filed with US patent application Ser. No. 12 / 465,164, named Gary Tavares et al. Partial continuation. In addition, this application is entitled "Golf Club Assembly and Golf Club With Aerodynamic Features" filed on January 27, 2010, and priority of provisional application 61 / 298,742, in which Gary Tavares et al. Is named as the inventor. Insist on the benefits. Each of these earlier applications is hereby incorporated by reference in its entirety.

FIELD Aspects of the present invention generally relate to golf clubs and golf club heads, particularly golf clubs and golf club heads having improved aerodynamic characteristics.

Background The distance traveled by a golf ball when hit by a golf club is largely determined by the club head speed at the point of collision with the golf ball. On the other hand, the club head speed can be affected by the wind resistance or drag exerted by the club head during the entire swing, especially given the large club head size of the driver. In particular, driver or fairway wood club heads generate significant aerodynamic drag during their swing trajectory. The drag generated by the club head leads to a reduced club head speed and thus a reduced travel distance after hitting the golf ball.

  The air is substantially parallel to the airflow direction and flows in a direction opposite the golf club head trajectory above the surface of the golf club head. An important factor affecting the drag is the behavior of the boundary layer of the airflow. A “boundary layer” is a thin air layer that is in close proximity to the surface of a club head during movement. As the air stream moves over the surface, it encounters increasing pressure. This pressure increase is called “back pressure gradient” because it slows and stalls the airflow. If the pressure continues to increase, the airflow will continue to slow down to zero velocity, at which point it will separate from the surface. After entraining the surface of the club head, the airflow is separated from the surface by stall in the airflow boundary layer. Separation of the airflow from the surface creates a low pressure separation region behind the club head (ie, the trailing edge defined relative to the direction of air flowing over the club head). This low pressure separation region creates drag. The greater the separation area, the greater the pressure drag.

  One way to reduce or minimize the size of the low pressure separation region is by providing a streamlined form that slows or eliminates laminar airflow separation from the club surface by maintaining laminar flow as long as possible. It is.

  Reducing the club head drag during the entire downswing prior to the collision point as well as at the collision point will result in an improved club head speed and increased travel distance of the golf ball. When analyzing a golfer's swing, the heel / hosel region of the club head leads the swing between a substantial portion of the downswing, and only the ball striking surface at (or just before) the point of impact with the golf ball Noted that leading the swing. The phrase “leading the swing” is intended to describe the portion of the club head that faces the direction of the swing ballistic. In the discussion, the golf club and golf club head are considered to be in the 0 ° orientation, that is, the collision point when the ball striking face leads the swing. It was noted that during the downswing, the golf club could rotate about 90 ° or more about the longitudinal axis of its shaft during a 90 ° downswing before the point of impact with the golf ball.

  During this final 90 ° part of the downswing, the club head can accelerate from about 65 miles per hour (mph) to over 100 mph, and for some professional golfers, it can accelerate to 140 mph. In addition, as the club head speed increases, the drag acting on the club head typically also increases. Thus, as this club head moves at a speed of 100 mph or more during this final 90 ° portion of the downswing, the drag acting on the club head can significantly delay any further acceleration of the club head.

  A club head designed to reduce head drag at the point of impact or from the perspective of the club face leading the swing, during the other phases of the swing cycle, eg, the heel / hosel area of the club head When leading a downswing, it may not function well to reduce drag.

  It would be desirable to provide a golf club head that reduces or overcomes some or all of the difficulties inherent in prior known devices. Certain advantages will be apparent to those skilled in the art, i.e., those skilled in the art or having experience in the art, in light of the following disclosure of the invention and detailed description of particular embodiments.

SUMMARY The present application discloses a golf club head having improved aerodynamic performance. According to certain aspects, a golf club head can include a body member having a ball striking surface, a crown, a toe, a heel, a sole, a rear portion, and a hosel region located at the intersection of the ball striking surface, the heel, the crown, and the sole. . The drag reduction structure on the body member is the golf downswing from the end of the backswing to the point of impact with the golf ball, possibly until the impact with the golf ball and at least the final 90 ° downswing just before it. Can be configured to reduce the drag of the club head during at least a portion thereof.

According to certain aspects, a golf club head for a driver having a volume of 400 cc or greater and a club width to face length ratio of 0.90 or greater includes a body member having a crown, a sole, and a heel. A leading edge may be included on the heel that is defined as the surface of the heel having a vertical bevel when the club head is at a 60 degree lie angle position. The body member may further have a first cross section including a tip point located on the leading edge, a first crown side surface extending from the tip point, and a first sole side surface extending from the tip point. The first cross section may face perpendicular to the center line of the club head. The tip point may represent the origin of the first x ₁ and z ₁ coordinate system that is oriented in the plane of the first cross section at a roll angle of about 15 °. The first crown side surface can be defined by the following spline points.

According to a particular aspect, the first sole side surface can be defined by the following spline points.

According to another aspect, the body member includes a tip point located on the leading edge, a second crown side surface extending from the tip point, and a second sole side surface extending from the tip point. It may further have a cross section. The second cross section may be about 70 ° from the center line of the club head. The tip point may further represent the origin of a _second x ₂ and z ₂ coordinate system that is oriented in the plane of the second cross section at a roll angle of about 15 °. The second crown side surface can be defined by the following spline points.

The second sole side surface can be defined by the following spline points.

  According to yet another aspect, the body member can be configured to be attached to a shaft having a longitudinal axis, and the tip point can be located about 15 mm to about 25 mm from the longitudinal axis of the shaft. Alternatively, the tip point may be located about 20 mm from the longitudinal axis of the shaft.

  According to certain aspects, the club head may have a volume of 420 cc or greater. The club head can have a face height of 53 mm or more. In addition, a club width to face length ratio of 0.92 or greater.

  According to certain aspects, the body member may further include a groove extending at least partially along the length of the tow and extending at least partially along the length of the back surface. The groove may be a Kammback feature.

  According to yet another aspect, the body member may further include a diffuser located on the sole and oriented at an angle of about 10 ° to about 80 ° from the center line of the club head. Alternatively, the diffuser may be oriented at an angle of about 50 ° to about 70 ° from the center line of the club head.

According to a particular aspect, the golf club head can include a first cross section oriented perpendicular to the center line of the club head, and x ₁ and z ₁ of the first crown side surface curve of the first cross section. The coordinates can be defined by the following Bezier equation.
x _1U = 3 (17) (1-t) t ² + (48) t ³
z _1U = 3 (10) (1-t) ² t + 3 (26) (1-t) t ² + (26) t ³
Range: 0 ≦ t ≦ 1

According to another aspect, the x ₁ and z ₁ coordinates of the first sole-side surface curve of the first cross section can be defined by the following Bezier equation.
x _1L = 3 (11) (1-t) t ² + (48) t ³
z _1L = 3 (-10) (1-t) ² t + 3 (-26) (1-t) t ² + (-32) t ³
Range: 0 ≦ t ≦ 1

The golf club head may further include a second cross-section that faces about 70 ° from the center line of the club head. The x _2U and z _2U coordinates of the second crown side surface curve of the second cross section can be defined by the following Bezier equation.
x _2U = 3 (19) (1-t) t ² + (48) t ³
z _2U = 3 (10) (1-t) ² t + 3 (25) (1-t) t ² + (25) t ³
Range: 0 ≦ t ≦ 1

Further, the x _1L and z _1L coordinates of the second sole-side surface curve of the second cross section can be defined by the following Bezier equation.
x _2L = 3 (13) (1-t) t ² + (48) t ³
z _2L = 3 (-10) (1-t) ² t + 3 (-26) (1-t) t ² + (-30) t ³
Range: 0 ≦ t ≦ 1

  According to yet another aspect, the body member may have a first cross section that is about 90 ° from the center line of the club head and a second cross section that is about 45 ° from the center line of the club head. Each of the first cross section and the second cross section may include a tip point located on the heel, and may have a crown side surface extending from the tip point and a sole side surface extending from the tip point. The first cross-section can have a first airfoil surface in the heel and a first concave surface opposite the first airfoil surface. The second cross-section can have a second airfoil surface in the heel and a second concave surface opposite the second airfoil surface.

  The first concave surface and the second concave surface may be formed by continuous grooves extending at least partially along the length of the tow and at least partially along the length of the back surface.

  According to certain aspects, golf clubs including the disclosed golf club heads are also provided.

  These and further features and advantages disclosed herein will be further understood from the following detailed disclosure of specific embodiments.

1 is a perspective view of an exemplary aspect of a golf club with grooves formed in the club head. FIG. FIG. 1B is an enlarged view of the club head of FIG. 1A provided with an orientation axis. 1B is a side perspective view of a club head of the golf club of FIG. 1A. FIG. FIG. 1B is a rear elevation view of the club head of the golf club of FIG. 1A. FIG. 1B is a side elevational view of the club head of the golf club of FIG. 1A viewed from the heel side of the club head. FIG. 1B is a plan view of the sole of the club head of the golf club of FIG. 1A. FIG. 1B is a bottom perspective view of the club head of the golf club of FIG. 1A. 1B is a side elevation view of an alternate embodiment of the club head of the golf club of FIG. 1A viewed from the toe side of the club head. FIG. 8 is a rear elevation view of the club head of FIG. FIG. 8 is a side elevational view of the club head of FIG. 7 viewed from the heel side of the club head. FIG. 8 is a bottom perspective view of the club head of FIG. It is a typical time course front view of a typical golfer's downswing. It is a top plan view of a club head showing yaw. It is a heel side elevation view of a club head showing a pitch. It is a front elevation view of a club head showing a roll. Figure 6 is a graph of each yaw angle, pitch angle and roll angle as a function of club head position during a typical downswing. The club head 14 (both top plan view and front elevation view) and the typical orientation of the airflow over the club head at points A, B and C in FIG. 11 respectively are schematically shown. FIG. 6 is a top plan view of a club head of certain exemplary aspects. FIG. 16 is a front elevation view of the club head of FIG. FIG. 16 is a toe side elevation view of the club head of FIG. FIG. 16 is a rear elevation view of the club head of FIG. FIG. 16 is a heel side elevational view of the club head of FIG. FIG. 16 is a bottom perspective view of the club head of FIG. FIG. 16 is a bottom perspective view of an alternative embodiment of a club head similar to the club head of FIG. 15 but without a diffuser. FIG. 10 is a top plan view of a club head of another exemplary aspect. FIG. 22 is a front elevation view of the club head of FIG. 21. FIG. 22 is a toe side elevation view of the club head of FIG. 21. FIG. 22 is a rear elevation view of the club head of FIG. 21. FIG. 22 is a heel side elevational view of the club head of FIG. 21. FIG. 22 is a bottom perspective view of the club head of FIG. FIG. 22 is a bottom perspective view of an alternative embodiment of a club head similar to the club head of FIG. 21 but without a diffuser. FIG. 7 is a top plan view of the club head of FIGS. 1-6 without a diffuser at a 60 degree lie angle position showing a cross-sectional cut obtained through point 112. FIG. 28 is a front elevation view of the club head of FIG. 27 in a 60 degree lie angle position. 28 is a cross-sectional cut obtained through the line XXIX-XXIX in FIG. 28 is a cross-sectional cut obtained through the line XXIX-XXIX in FIG. 28 is a cross-sectional cut obtained through the line XXX-XXX in FIG. 28 is a cross-sectional cut obtained through the line XXX-XXX in FIG. 28 is a cross-sectional cut obtained through the line XXXI-XXXI in FIG. 28 is a cross-sectional cut obtained through the line XXXI-XXXI in FIG. FIG. 6 is a schematic view (upper plan view and front elevation view) of a club head showing certain other physical parameters.

  The figures referred to above are not necessarily drawn to scale, but are to be understood as providing representations of particular aspects of the invention, which are conceptual in nature and illustrate the principles involved. It's just what you do. Some features of the golf club head shown in the drawings may be expanded or distorted with respect to other features for ease of explanation and understanding. In the drawings, the same reference numbers are used for similar or identical components and features shown in various alternative embodiments. The golf club heads disclosed herein will have configurations and components that are determined in part by the intended application and environment in which they are used.

DETAILED DESCRIPTION An exemplary embodiment of a golf club 10 is shown in FIG. 1A and includes a shaft 12 and a golf club head 14 attached to the shaft 12. As shown in FIG. 1A, the golf club head 14 may be a driver. The shaft 12 of the golf club 10 can be made of a variety of materials such as steel, aluminum, titanium, graphite or composites, and alloys and / or combinations thereof, including materials conventionally known and used in the art. There may be. In addition, conventional methods known and used in the art (eg, via adhesive or cement in hosel elements, via fusion techniques (eg, welding, brazing, soldering, etc.), threads or others The shaft 12 can be attached to the club head 14 in any desired manner, including through mechanical connectors (including releasable and adjustable mechanisms), via friction fit, via retention element structure, etc. Placing a grip or other handle element 12a on the shaft 12 can provide the golfer with a slip resistant surface for gripping the golf club shaft 12. Conventional methods known and used in the art (eg, via glue or cement, via threads or other mechanical connectors (including releasable connectors), via fusion technology, friction fit The grip element 12a can be attached to the shaft 12 in any desired manner, including via, via a retaining element structure, etc.

  In the exemplary structure of FIG. 1A, the club head 14 includes a body member 15 to which the shaft 12 is attached in a hosel or socket 16 for receiving the shaft 12 in a known manner. Body member 15 includes a plurality of portions, regions or surfaces as defined herein. The exemplary body member 15 includes a ball striking surface 17, a crown 18, a toe 20, a back surface 22, a heel 24, a hosel region 26 and a sole 28. The back surface 22 is disposed on the opposite side of the ball striking surface 17, extends between the crown 18 and the sole 28, and further extends between the toe 20 and the heel 24. This particular example body member 15 further includes a skirt or comeback feature 23 and a recess or diffuser 36 formed in the sole 28.

Referring to FIG. 1B, the ball striking surface region 17 is a region or surface that may be essentially flat or may have a slight curvature or curvature (also known as a “bulge”). Although the golf ball can contact the ball striking surface 17 at any spot on the face, the desired contact point 17a of the ball striking surface 17 with the golf ball is usually approximately the center in the ball striking surface 17. In the present disclosure, a line L _T drawn in contact with the surface of the striking face 17 at a desired contact point 17a defines a direction parallel to the ball striking surface 17. The family of lines drawn in contact with the surface of the striking surface 17 at the desired contact point 17a defines the striking surface plane 17b. Line L _P defines a direction perpendicular to the ball striking face plane 17b. Furthermore, at the collision point (and at the address position, ie when the club head is placed on the ground adjacent to the golf ball before the start of the backswing), the hitting plane 17b should not be perpendicular to the ground. In general, the striking surface 17 can be provided with a loft angle α. The loft angle α is generally intended to affect the initial upper trajectory of the golf ball at the point of impact. By rotating a line L _P drawn perpendicular to the striking face plane 17b through the negative loft angle α, a line T ₀ directed along the desired club head trajectory at the collision point is defined. Generally, this impact point club head trajectory direction T ₀ is perpendicular to the longitudinal axis of the club shaft 12.

Referring further to FIG. 1B, a set of reference axes (X ₀ , Y ₀ , Z ₀ ) associated with the club head (eg, USGA Rules of Golf, Appendix) that are oriented 60 degrees lie angle relative to a zero degree face angle. II and FIG. 28) can now be applied to the club head 14. The Y ₀ axis extends from the desired contact point 17a along the contact point club head trajectory line in a direction opposite to the T ₀ direction. The X ₀ axis generally extends from the desired contact point 17a toward the toe 20, and is perpendicular to the Y ₀ axis at the 60 ° lie angle position and parallel to the horizontal line to the club. Thus the line L _T, when drawn parallel to the ground coincides with the X ₀ axis. The Z ₀ axis extends from the desired contact point 17a generally vertically upward and perpendicular to both the X ₀ axis and the Y ₀ axis. In the present disclosure, the “center line” of the club head 14 is considered to coincide with the Y ₀ axis (and the T ₀ line). As used herein, the term “backward” generally refers to the direction opposite the contact point club head ballistic direction T ₀ , ie, the positive direction of the Y ₀ axis.

Referring now to FIGS. 1-6, the crown 18 located on the upper side of the club head 14 extends rearward from the ball striking face 17 toward the back surface 22 of the golf club head 14. From the bottom of the club head 14, i.e. when looking in the positive direction along the Z ₀ axis, the crown 18 is not visible.

A sole 28 located on the lower side or the ground side of the club head 14 opposite to the crown 18 extends rearward from the striking surface 17 toward the back surface 22. Similar to crown 18, sole 28 extends from heel 24 to toe 20 across the width of club head 14. From the top of the club head 14, that is, when seen in the negative direction along the Z ₀ axis, the sole 28 is not visible.

Referring to FIGS. 3 and 4, the back surface 22 is disposed on the opposite side of the ball striking face 17 and is located between the crown 18 and the sole 28 and extends from the heel 24 to the toe 20. The club head 14 from the front, that is, when seen in the positive direction along the Y ₀ axis, the back 22 is not visible. In some golf club head configurations, the back 22 can be provided with a skirt or comeback feature 23.

The heel 24 extends from the ball striking surface 17 to the back surface 22. The club head 14 from the toe side, that is, when along the X ₀ axis viewed in the positive direction, the heel 24 is not visible. In some golf club head configurations, the heel 24 can be provided with a skirt or comeback feature 23 or a portion of the skirt or a portion of the comeback feature 23.

The toe 20 is shown as extending from the ball striking face 17 to the back face 22 on the side of the club head 14 opposite the heel 24. When viewing the club head 14 from the heel side, i.e. in a negative direction along the X ₀ axis, the tow 20 is not visible. In some golf club head configurations, the tow 20 can be provided with a skirt or comeback feature 23 or a portion of the skirt or a portion of the comeback feature 23.

  A socket 16 for receiving the shaft is located in the hosel region 26. The hosel region 26 is shown as being located at the intersection of the ball striking face 17, the heel 24, the crown 18 and the sole 28, and may include the portions of the heel 24, the crown 18 and the sole 28 that are adjacent to the hosel 16. In general, the hosel region 26 includes a surface that indicates a transition from the socket 16 to the ball striking face 17, the heel 24, the crown 18 and / or the sole 28.

  Accordingly, the terms striking surface 17, crown 18, toe 20, back surface 22, heel 24, hosel region 26 and sole 28 should be understood to mean general regions or portions of body member 15. In some cases, these regions or portions may overlap each other. Further, it should be understood that the use of these terms in the present disclosure may differ from the use of these or similar terms in other literature. In general, the terms toe, heel, ball striking surface and back are intended to mean the four sides of a golf club that make up the outer contour of the body member when viewed directly from above when the golf club is in the address position. Should be understood.

  In the embodiment shown in FIGS. 1-6, the body member 15 can be generally described as a “square head”. The crown 18 and sole 28 of the square head body member 15 are not truly square in the geometric sense, but are substantially square compared to a traditional round club head.

  Another embodiment of the club head 14 is shown as club head 54 in FIGS. Club head 54 has a more traditional round head shape. The phrase “round head” should not be understood to mean a perfectly circular head, but rather a head having a generally or substantially circular contour.

  FIG. 11 is a schematic front view of motion capture analysis of at least a portion of a golfer's downswing. As shown in FIG. 11, at the collision point (I) with the golf ball, it can be considered that the ball striking surface 17 is substantially perpendicular to the moving direction of the club head 14 (in practice, it is usually about 2 By providing a loft of -4 °, the ball striking surface 17 is separated from the perpendicular by that amount). During the golfer's backswing, the ball striking surface 17 starting at the address position is away from the golfer (ie, for right-handed golfers) because of the golfer's hips, torso, arms, wrists and / or hand rotation. Twisted (clockwise when viewed from above). During the downswing, the ball striking surface 17 rotates and returns to the collision point position.

In fact, with reference to FIGS. 11 and 12A-12C, during the downswing, the club head 14 is rotated by the yaw angle (R _OT -Z) (see FIG. 12A) (as the club head 14 rotates about the vertical Z ₀ axis) Change, as defined herein, pitch angle (R _OT -X) (see FIG. 12B), change in roll head angle (defined herein as rotation of club head 14 about the X ₀ axis) Experience a change in (R _OT -Y) (see FIG. 12C) (defined herein as rotation of the club head 14 about the Y ₀ axis).

By using the yaw angle, pitch angle, and roll angle, the orientation of the club head 14 with respect to the airflow direction (considered to be opposite to the instantaneous trajectory of the club head) can be provided. At the collision point and address position, the yaw angle, pitch angle and roll angle can be considered to be 0 °. For example, referring to FIG. 12A, when viewed along the Z ₀ axis, the center line L ₀ of the club head 14 faces 45 ° with respect to the airflow direction at a 45 ° yaw angle measurement. As another example, referring to FIG. 12B, when viewed along the X ₀ axis, the pitch angle of 20 °, the center line L ₀ of the club head 14 faces 20 ° with respect to the air flow direction. Also, referring to FIG. 12C, when viewed along the Y ₀ axis, the X ₀ axis of the club head 14 faces 20 ° with respect to the airflow direction at a roll angle of 20 °.

Figure 13 is a graph of each yaw angle (R _OT -Z), pitch angle (R _OT -X) and roll angle (R _OT -Y) as a function of club head 14 position during a typical downswing. is there. By referring to FIGS. 11 and 13, it can be recognized that the ball striking surface 17 of the golf club head 14 does not lead the swing during the majority of the downswing. At the beginning of a golfer's downswing, the heel 24 may essentially lead the swing because of about 90 ° yaw rotation. Furthermore, at the beginning of a golfer's downswing, the lower part of the heel 24 essentially leads the swing because of the roll rotation of about 10 °. During the downswing, the orientation of the golf club and club head 14 changes from about 90 ° yaw at the beginning of the downswing to about 0 ° yaw at the point of impact.

Further, referring to FIG. 13, normally, the change in the yaw angle (R _OT -Z) during the downswing is not constant. During the first part of the downswing, the change in yaw angle is typically about 20 ° as the club head 14 moves from the back of the golfer to approximately shoulder height. Thus, if the club head 14 is approximately shoulder height, the yaw is about 70 °. When the club head 14 is approximately at the height of the torso, the yaw angle is about 60 °. During the final 90 ° portion of the downswing (from the body height to the collision point), the golf club typically moves through a yaw angle of about 60 ° to a yaw angle of 0 ° at the collision point. However, the change in yaw angle during this part of the downswing is generally not constant, and in fact, the golf club head 14 is usually only about 20 ° yaw only at the final 10 degree downswing and 0 ° at the point of impact. Ends with no yaw. During this second 90 ° portion of the downswing, a yaw angle of 45 ° -60 ° can be considered representative.

Similarly, with further reference to FIG. 13, the change in roll angle (R _OT -Y) during a downswing is typically not constant. During the first part of the downswing, the roll angle is substantially constant as the club head 14 moves from the back of the golfer to a position approximately at the level of the torso, for example between about 7 ° and 13 °. However, the change in roll angle during the portion of the downswing from about the torso height to the point of impact is generally not constant, and in fact, the golf club head 14 typically has a club head 14 that is approximately from the torso height to about the knee. The roll angle increases from about 10 ° to about 20 ° when swinging to the height of, and then the roll angle decreases to 0 ° at the collision point. A 15 ° roll angle between the torso and knee of the downswing can be considered typical.

  During the downswing, the speed of the golf club head also changes from the first 0 mph of the downswing to 65-100 mph at the collision point (or higher for top rank golfers). At low speeds, ie during the first part of the downswing, drag due to air resistance may not be as significant. However, during the downswing part when the club head 14 is flush with the golfer's torso and is then swung to the point of collision, the club head 14 is at a substantial speed (eg 60 mph up to 130 mph for professional golfers) Move with. During this part of the downswing, drag due to air resistance causes the golf club head 14 to impact the golf ball at a speed slower than would be possible without air resistance.

  Referring again to FIG. 11, several points (A, B, and C) along the golfer's typical downswing have been identified. At point A, the club head 14 is at a downswing angle of about 120 °, ie, about 120 ° from the point of impact with the golf ball. At this point, the club head may already be moving at about 70% of its maximum speed. 14A schematically illustrates a typical orientation of the club head 14 and the airflow over the club head 14 at point A. FIG. The yaw angle of the club head 14 can be about 70 °, which means that the heel 24 is no longer substantially perpendicular to the air flowing over the club head 14, but rather the heel 24 is above the club head 14. Means about 20 ° to the perpendicular to the air flowing through. Also, at this point during the downswing, the club head 14 can have a roll angle of about 7 ° to 10 °, that is, the heel 24 of the club head 14 rolls upward 7 ° to 10 ° with respect to the airflow direction. Also note that it works. Accordingly, the heel 24 (slightly inclined so as to expose the lower part (sole side part) of the heel 24) leads the swing in combination with the heel side surface of the hosel region 26.

  At point B shown in FIG. 11, the club head 14 is at a downswing angle of about 100 °, ie, about 100 ° from the point of impact with the golf ball. At this point, the club head 14 may now be moving at about 80% of its maximum speed. 14B schematically illustrates a typical orientation of the club head 14 and the airflow over the club head 14 at point B. FIG. The yaw angle of the club head 14 can be about 60 °, which means that the heel 24 is oriented about 30 ° with respect to the normal to the air flowing over the club head 14. Further, at this point during the downswing, the club head 14 may have a roll angle of about 5 ° to 10 °. Therefore, the heel 24 is still slightly inclined so as to expose the lower part (sole side part) of the heel 24. This portion of the heel 24 leads the swing in combination with some slight involvement of the heel side surface of the hosel region 26 and here the striking surface side surface of the hosel region 26. In fact, in this orientation of the yaw and roll angles, the intersection of the heel side surface and the striking surface side surface of the hosel region 26 provides the foremost surface (in the ballistic direction). Recognize that the heel 24 and hosel region 26 are associated with the leading edge (as defined by the airflow direction) and the toe 20, the portion of the back 22 adjacent to the toe 20 and / or their intersection is associated with the trailing edge. .

  At point C in FIG. 11, the club head 14 is in a downswing position of about 70 °, ie, about 70 ° from the point of impact with the golf ball. At this point, the club head 14 may now be moving at about 90% or more of its maximum speed. 14C schematically illustrates a typical orientation of the club head 14 and the airflow over the club head 14 at point C. FIG. The club head 14 has a yaw angle of about 45 °, which means that the heel 24 is no longer substantially perpendicular to the air flowing over the club head 14, but rather about 45 ° to the normal to the airflow. It means to face. Further, at this point during the downswing, the club head 14 may have a roll angle of about 20 °. Accordingly, the heel 24 (inclined approximately 20 ° so as to expose the lower portion (sole side portion) of the heel 24) is further related to the heel side surface of the hosel region 26 and the striking surface side surface of the hosel region 26. Lead the swing in combination with. In this orientation of yaw angle and roll angle, the intersection of the heel side surface and the striking surface side surface of the hosel region 26 provides the foremost surface (in the ballistic direction). The heel 24 and hosel region 26 are also associated with the leading edge (as defined by the airflow direction), the portion of the toe 20 adjacent to the back surface 22, the portion of the back surface 22 adjacent to the toe 20 and / or the intersection thereof is the trailing edge Can be recognized as related to

  Referring again to FIGS. 11 and 13, it can be seen that the integral or sum of drag during the entire downswing provides the total drag experienced by the club head. Calculating the drag reduction percentage for the entire swing can produce very different results than calculating the drag reduction percentage at the collision point alone. The drag reduction structure described below provides various means for reducing the total drag as well as simply reducing the drag at the collision point (I).

  A further embodiment of club head 14 is shown as club head 64 in FIGS. The club head 64 is generally a “square head” shaped club. Club head 64 includes a ball striking surface 17, a crown 18, a sole 28, a heel 24, a toe 20, a back surface 22 and a hosel region 26.

  A comeback feature 23 located between the crown 18 and the sole 28 extends continuously from the front portion of the tow 20 (ie, the region closer to the ball striking face 17 than the back portion 22) to the back portion 22 and across the back portion 22. To the heel 24 and into the rear part of the heel 24. Thus, as best seen in FIG. 17, the comeback feature 23 extends along most of the length of the tow 20. As best seen in FIG. 19, the comeback feature extends along a small portion of the length of the heel 24. In this particular embodiment, the comeback feature 23 is a concave groove having a maximum height (H) that can range from about 10 mm to about 20 mm and a maximum depth (D) that can range from about 5 mm to about 15 mm. It is.

  As shown in FIG. 20A, one or more diffusers 36 may be formed in the sole 28. In an alternative embodiment of club head 14 shown as club head 74 in FIG. 20B, sole 28 may be formed without a diffuser.

  Referring again to FIGS. 16, 18 and 19, the heel 24 may be provided with a streamlined region 100 having a surface 25 generally shaped as a leading airfoil surface from the tapered end of the comeback feature 23 to the hosel region 26. it can. As disclosed in more detail below, this streamlined region 100 and wing-shaped surface 25 provide aerodynamic benefits as air flows over the club head 14 during the downswing stroke of the golf club 10. It can be constituted as follows. In particular, the wing shaped surface 25 of the heel 24 can transition smoothly and gradually into the crown 18. Further, the wing-shaped surface 25 of the heel 24 can transition smoothly and gradually into the sole 28. Furthermore, the wing-shaped surface 25 of the heel 24 can transition smoothly and gradually into the hosel region 26.

  A further embodiment of club head 14 is shown as club head 84 in FIGS. Club head 84 is generally a “round head” shaped club. Club head 84 includes a ball striking surface 17, a crown 18, a sole 28, a heel 24, a toe 20, a back surface 22 and a hosel region 26.

  Referring to FIGS. 23-26, a groove 29 located below the outermost edge of the crown 18 extends continuously from the front portion of the tow 20 to the back 22 and crosses the back 22 to the heel 24. , And into the front part of the heel 24. Thus, as best seen in FIG. 23, the groove 29 extends along most of the length of the tow 20. As best seen in FIG. 25, the groove 29 also extends along most of the length of the heel 24. In this particular embodiment, groove 29 is a concave groove having a maximum height (H) that can range from about 10 mm to about 20 mm and a maximum depth (D) that can range from about 5 mm to about 10 mm. is there. In addition, as best shown in FIG. 26A, the sole 28 includes a shallow step 21 that is generally parallel to the groove 29. Step 21 smoothly joins the surface of hosel region 26.

  A diffuser 36 may be formed in the sole 28 as shown in FIGS. 20A and 26A. In these particular embodiments, the diffuser 36 extends from the region of the sole 28 adjacent to the hosel region 26 toward the toe 20, the back surface 22, and the intersection of the toe 22 and the back surface 22. In an alternative embodiment of club head 14 shown as club head 94 in FIG. 26B, sole 28 may be formed without a diffuser.

  Some of the exemplary drag reduction structures described in more detail below are where the ball striking surface 17 generally leads the swing, i.e., when air flows over the club head 14 from the ball striking surface 17 toward the back surface 22. Various means of maintaining laminar airflow over one or more surfaces of the club head 14 can be provided. In addition, some of the exemplary drag reduction structures described in more detail below are where the hosel region 26 generally leads the swing, i.e., air over the club head 14 from the heel 24 to the toe 20. When flowing, various means of maintaining laminar airflow over one or more surfaces of the club head 14 can be provided. In addition, some of the exemplary drag reduction structures described in more detail below may be used when the heel 24 generally leads the swing, i.e., the air over the club head 14 from the hosel region 26 to the toe 20 and / or the back. When flowing toward 22, various means of maintaining laminar airflow over one or more surfaces of the club head 14 can be provided. The exemplary drag reduction structures disclosed herein can be incorporated into the club head 14 alone or in combination and are applicable to any and all aspects of the club head 14.

  According to certain aspects and with reference to FIGS. 3-6, 8-10, 15-31, for example, located on the heel 24 proximate (or adjacent to, optionally including a portion thereof) the hosel region 26 A drag reducing structure can be provided as the streamline region 100. This streamline region 100 can be configured to achieve aerodynamic benefits as air flows over the club head 14 during the downswing stroke. As described above with respect to FIGS. 11-14, in the latter half of the downswing where the speed of the club head 14 is significant, the club head 14 may rotate through a yaw angle of about 70 ° to 0 °. In addition, due to the non-linear nature of yaw angle rotation, the heel 24 configuration designed to reduce drag due to airflow when the club head 14 faces a yaw angle of about 70 ° to about 45 ° is the largest Profits can be realized.

  Accordingly, it may be advantageous to provide a streamlined region 100 in the heel 24 because of yaw angle rotation during the downswing. For example, by providing a smooth, aerodynamically shaped leading surface in the streamlined region 100, air can flow through the club head with minimal interruption. Such a streamline region 100 may be shaped to minimize resistance to airflow as air flows from the heel 24 toward the toe 20, the back surface 22, and / or the intersection of the back surface 22 and the toe 20. it can. The streamline region 100 may be advantageously located on the heel 24 adjacent to the hosel region 26 and possibly even overlapping it. This streamlined region of the heel 24 can form part of the leading surface of the club head 14 in a significant portion of the downswing. The streamline region 100 can extend along the entire heel 24. Alternatively, the streamline region 100 may have a more limited range.

  Referring to FIGS. 27 and 28, according to certain aspects, the streamline region 100 referenced, for example, in FIGS. 3-6, 8-10 and 15-31 is from the longitudinal axis of the shaft 12, or the club is at zero degrees. The length of the heel 24 is about 15 mm to about 70 mm in the Y direction measured from the point where the vertical axis of the shaft 12 intersects the ground when it is at a lie angle position of 60 degrees with respect to the face angle, that is, the “ground zero” point. It can be provided along at least. In these embodiments, the streamline region 100 may extend beyond a countable range in some cases. In certain other embodiments, the streamline region 100 may be provided along the length of the heel 24 at least about 15 mm to about 50 mm in the Y direction as measured from the ground zero point. In a further embodiment, the streamline region 100 can be provided along the length of the heel 24 at least about 15 mm to about 30 mm, or even at least about 20 mm to about 25 mm in the Y direction as measured from the ground zero point.

  FIG. 27 is shown with three cross-section cuts. Sections along the line XXIX-XXIX are shown in FIGS. 29A and 29B. Cross sections taken along line XXX-XXX are shown in FIGS. 30A and 30B. Cross sections taken along line XXXI-XXXI are shown in FIGS. 31A and 31B. The cross-sections shown in FIGS. 29-31 are used to illustrate the specific characteristics of the club head 14 of FIGS. 1-6 and the characteristics of the club head embodiments shown in FIGS. 7-10, 15-20, and 21-26. It is also used to schematically show

According to certain aspects, and with reference to FIGS. 29A and 29B, the streamline region 100 may be defined by a cross-section 110 in the heel 24. 29A and 29B show a cross section 110 of the club head 14 taken through line XXIX-XXIX in FIG. A portion of the cross section 110 cuts into the sole 28, crown 18 and heel 24. Further, at least a portion of the cross-section 110 exists within the streamline region 100, and therefore, as discussed above, the leading portion of the cross-section 110 can resemble an airfoil. Cross-section 110 is obtained parallel to the X ₀ axis in a vertical plane located approximately 20 mm in the Y direction as measured from the ground zero point (ie, approximately 90 degrees from the Y ₀ axis (ie, within ± 5 degrees)). . In other words, cross 110 is oriented perpendicular to the Y ₀ axis. This cross section 110 is thus oriented in the direction from the heel 24 to the toe 20 with respect to the air flowing over the club head 14.

Referring to FIGS. 27, 29A and 29B, the leading edge 111 is located on the heel 24. The leading edge 111 generally extends from the hosel region 26 toward the back surface 22 and exists between the crown 18 and the sole 28. If the air flows parallel to the X ₀ axis toward the top of the club head 14 from the heel 24 to the toe 20, the leading edge 111 will be the first portion of the heel 24 to experience airflow. In general, at a leading edge 111, the slope of the surface of the cross-section 110 is perpendicular to the X ₀ axis, i.e., inclined in the club head 14 is at the 60 degree lie angle position is vertical.

The tip point 112 present on the leading edge 111 of the heel 24 can be defined at Y = 20 mm (see FIG. 27). Furthermore, it is possible to define a local coordinate system associated with the cross-section 110 and the distal end point 112, x-axis and z-axis extending from the center point 112, respectively 15 ° from X ₀ axis and Z ₀ axis associated with the club head 14 Toward the plane of section 110 at an angle of This orientation of the axis at 15 ° corresponds to a roll angle of 15 °, which is typical during the torso to knee part of the downswing (ie when the club head 14 approaches its maximum speed). It was thought that there was.

  Thus, according to certain aspects, the wing-shaped surface 25 of the streamline region 100 can be described as being “quasi-parabolic”. As used herein, the term “quasi-parabolic” refers to any point having a tip point 112 and two arms that bend smoothly and gradually away from the tip point 112 and away from each other on the same side of the tip point. Means a convex curve. The first arm of the wing-shaped surface 25 can be referred to as the crown curve or the upper curve 113. The other arm of the wing-shaped surface 25 can be referred to as the sole curve or the lower curve 114. For example, a hyperbolic branch can be considered to be quasiparabolic. Further, the quasiparabolic cross section used herein need not be symmetrical. For example, one arm of a quasi-parabolic cross section can be most closely represented by a parabola, and the other arm can be most closely represented by a hyperbola. As another example, the tip point 112 need not be centered between the two arms. In any case, the term “tip point” means the leading point of the semi-parabolic curve, ie the point where the two curves 113, 114 bend away from each other. In other words, a “quasi-parabolic” curve oriented by arms extending horizontally in the same direction has a maximum slope at the tip point 112, and the absolute value of the slope of the curves 113, 114 is the horizontal distance from the tip point 112. It decreases gradually and continuously as it increases.

30A and 30B show a cross section 120 of the club head 14 taken through line XXX-XXX in FIG. According to certain aspects, and with reference to FIGS. 30A and 30B, the streamlined region 100 may be defined by its cross-section 120 within the heel 24. As shown in FIG. 27, the cross section 120 is obtained at an angle of about 70 degrees (ie, within a range of ± 5 degrees) with respect to the Y ₀ axis rotating around the tip point 112. Therefore, this cross section 120 is also directed in the direction from the heel 24 to the toe 20 with respect to the air flowing over the club head 14, where the air flow direction toward the intersection of the toe 20 and the back surface 22 is at a higher angle than the cross section 110. (See FIG. 14A). Similar to the cross-section 110, the cross-section 120 includes a crown side curve or upper curve 123 extending from the tip point 112 and a sole side curve or lower curve 124 also extending from the tip point. The tip point 112 associated with the leading edge 111 of the heel 24 at Y = 20 mm is illustrated.

The x-axis and z-axis associated with cross-section 120 are oriented in the plane of cross-section 120 at an angle of 15 ° from the X _0- axis and Z _0- axis associated with club head 14, respectively. This orientation of the cross-sectional axis at 15 ° again corresponds to a roll angle of 15 °, which is typical during the downswing torso to knee portion (ie when the club head 14 approaches its maximum speed). It was thought that

  31A and 31B show a cross section 130 of the club head 14 taken through line XXXI-XXXI in FIG. According to certain aspects, and with reference to FIGS. 31A and 31B, the streamline region 100 may be defined by its cross-section 130 within the heel 24. As discussed above, the cross section 130 of the streamline region 100 may resemble the leading edge of the airfoil. As shown in FIG. 27, the cross section 130 is obtained at an angle of about 45 degrees (ie, within a range of ± 5 degrees) with respect to the Y axis that rotates about the tip point 112. Accordingly, this cross-section 130 is generally oriented in the direction from the heel 24 to the back surface 22 for air flowing over the club head 14 (see FIG. 14C). Similar to cross-sections 110 and 120, cross-section 130 also includes a crown side curve or upper curve 133 extending from the tip point 112 and a sole side curve or lower curve 134 also extending from the tip point. Shown is the tip point 112 associated with the leading edge 111 of the heel 24 at Y = 20 mm measured from the ground zero point.

X-axis and z-axis associated with the cross-section 130, oriented in the plane of the cross-section 130 from the X ₀ axis and Z ₀ axis associated with the club head 14 at an angle of respectively 15 °. This orientation of the cross-sectional axis at 15 ° again corresponds to a roll angle of 15 °, which is typical during the downswing torso to knee portion (ie when the club head 14 approaches its maximum speed). It was thought that

  Referring to FIGS. 29A, 30A, and 31A, those skilled in the art will recognize that one way to characterize the shape of a curve is by providing a table of spline points. In these spline point tables, the tip point 112 is defined at (0, 0) and all coordinates of the spline point are defined with respect to the tip point 112. FIGS. 29A, 30A and 31A include x-axis coordinate lines at 12 mm, 24 mm, 36 mm, and 48 mm, where the spline points can be defined. Spline points can be defined in other x-axis coordinates, for example at 3 mm, 6 mm and 18 mm, but for clarity such coordinate lines are not included in FIGS. 29A, 30A and 31A.

As shown in FIGS. 29A, 30A and 31A, the z _U coordinate is associated with the upper curves 113, 123, 133 and the z _L coordinate is associated with the lower curves 114, 124, 134. In general, the upper curve is not the same as the lower curve. In other words, the cross-sections 110, 120, 130 can be asymmetric. As can be appreciated by reviewing FIGS. 29A, 30A, and 31A, this asymmetry, ie the difference between the upper and lower curves, can become more apparent as the cross section varies toward the back of the club head. . Specifically, the upper and lower curves of the section obtained at an angle of about 90 degrees with respect to the center line (see, for example, FIG. 29A) are the upper curves of the section obtained at an angle of about 45 degrees with respect to the center line. And may be more symmetric than the lower curve (see, eg, FIG. 31A). Further, referring again to FIGS. 29A, 30A, and 31A, the lower curve, in some exemplary embodiments, may remain relatively constant as the cross-section varies toward the back of the club head, while The curve can be flat.

  Referring to FIGS. 29B, 30B, and 31B, one skilled in the art will recognize that another way to characterize a curve is by fitting the curve to one or more functions. For example, because of the asymmetry of the upper and lower curves discussed above, the upper and lower curves of the cross-sections 110, 120, 130 can be independently curve fitted using a polynomial function. Thus, according to certain aspects, a quadratic or cubic polynomial, ie, a quadratic or cubic function, can sufficiently characterize the curve.

  For example, the quadratic function can be determined by constraining the vertex of the quadratic function to be the tip point 112, that is, the (0, 0) point. In other words, curve fitting may require a quadratic function to extend through the tip point 112. Further, curve fitting may require a quadratic function to be perpendicular to the x-axis at the tip point 112.

  Another mathematical technique that can be used for curve fitting involves the use of Bezier curves, which are parametric curves that can be used to model smooth curves. For example, Bezier curves are commonly used in computer numerical control (CNC) machines for controlling the processing of complex smooth curves.

By using the following generalized parametric curve using a Bezier curve, the x coordinate and z coordinate of the upper curve of the cross section can be obtained, respectively.
x _u = (1-t) ³ Px _u0 + 3 (1-t) ² t Px _u1 + 3 (1-t) t ² Px _u2 + t ³ Px _u3 formula (1a)
z _u = (1-t) ³ Pz _u0 + 3 (1-t) ² t Pz _u1 + 3 (1-t) t ² Pz _u2 + t ³ Pz _u3 formula (1b)
Range: 0 ≦ t ≦ 1
Px _u0 , Px _u1 , Px _u2 and Px _u3 are the control points of the x-coordinate Bezier curve associated with the upper curve, and Pz _u0 , Pz _u1 , Pz _u2 and Pz _u3 are the z-coordinate associated with the upper curve This is the control point of the Bezier curve.

Similarly, by using the following generalized parametric Bezier curve, the x coordinate and the z coordinate of the lower curve of the cross section can be obtained, respectively.
x _L = (1-t) ³ Px _L0 + 3 (1-t) ² t Px _L1 + 3 (1-t) t ² Px _L2 + t ³ Px _L3 formula (2a)
z _L = (1-t) ³ Pz _L0 + 3 (1-t) ² t Pz _L1 + 3 (1-t) t ² Pz _L2 + t ³ Pz _L3 formula (2b)
Range: 0 ≦ t ≦ 1
Px _L0 , Px _L1 , Px _L2 and Px _L3 are the control points of the x coordinate Bezier curve associated with the lower curve, and Pz _L0 , Pz _L1 , Pz _L2 and Pz _L3 are the z coordinate associated with the lower curve. This is the control point of the Bezier curve.

  Since curve fitting is generally used to fit data, one way to capture data may be to provide a curve that bounds the data. Thus, for example, with reference to FIGS. (126a, 126b), (135a, 135b), (136a, 136b) can be characterized as being present in a region where the pair of curves are curves 113, 114, 123, 124, A variation of up to ± 10% and even up to 20% of the z-coordinates of 133 and 134, respectively, can be represented, for example.

  Further, it will be noted that the cross sections 110, 120 and 130 presented in FIGS. 29-31 are cross sections of the club head 14 without the diffuser 36 provided on the sole 28. According to certain aspects, a diffuser 36 may be provided on the sole 28, and thus the lower curve of the cross section 110, 120 and / or 130 is different from the shape presented in FIGS. Further, according to certain aspects, the cross-sections 110, 120, and 130 can each include a comeback feature 23 at the trailing edge.

  Referring back to FIGS. 27 and 28, the description of cross-sections 110, 120 and 130 (FIGS. 29-31) is made using the tip point 112 (see FIG. 27) associated with the leading edge 111 of the heel 24 at Y = 20 mm. I notice that I helped. However, it is not necessary to accurately place the tip point 112 at Y = 20 mm. In the more general case, according to certain aspects, the tip point 112 may be located from about 10 mm to about 30 mm in the Y direction as measured from the “ground zero” point. In some embodiments, the tip point 112 may be located from about 15 mm to about 25 mm in the Y direction as measured from the “ground zero” point. A variation of plus or minus 1 millimeter in the location of the tip point can be considered acceptable. According to certain aspects, the tip point 112 may be located on the leading edge 111 of the heel 24 in the front half of the club head 14.

  According to certain aspects, and as best shown in FIG. 20B, the sole 28 extends across the width of the club head 14 from the heel 24 to the toe 20, with a generally convex and gentle widthwise curvature. Can extend. In addition, the smooth, non-intermittent wing-shaped surface 25 of the heel 24 can continue into the central region of the sole 28 and beyond. The generally convex and widthwise curvature of the sole may extend to the toe 20 across the entire sole 28. In other words, the sole 28 can be provided with a convex curve across the entire width from the heel 24 to the toe 20.

  Further, the sole 28 can extend across the length of the club head 14 from the ball striking face 17 to the back face 22 with a generally convex and smooth curvature. This generally convex curvature can extend from the vicinity of the ball striking surface 17 to the back surface 22 without transitioning from a positive curvature to a negative curvature. In other words, a convex curve can be provided on the sole 28 along the entire length from the ball striking surface 17 to the back surface 22.

  Alternatively, according to certain aspects, a recess or diffuser 36 can be formed in the sole 28, for example as shown in FIGS. 5, 20A and 26A. In the exemplary embodiment of FIG. 5, the recess or diffuser 36 is substantially V-shaped and the apex 38 of that shape is located proximal to the ball striking face 17 and the heel 24. That is, the apex 38 is located near the ball striking face 17 and the heel 24 and away from the skirt or comeback feature 23 and the toe 20. The recess or diffuser 36 includes a pair of legs 40 that extend proximal to the toe 20 and away from the ball striking face 17 and bend toward the skirt or camback structure 23 and away from the ball striking face 17.

  With further reference to FIG. 5, a plurality of secondary recesses 42 may be formed in the lower surface 43 of the recesses or diffuser 36. In the exemplary embodiment, each secondary recess 42 is a regular trapezoid, its small base 44 is close to the heel 24, its large base 46 is close to the toe 20, and the angled side 45 is a small base 44 with a large base 46. To join. In the exemplary embodiment, the depth of each secondary recess 42 varies from its maximum amount at the small base 44 to a large base 46 that is flush with the lower surface 43 of the recess or diffuser 36.

  Thus, according to certain aspects, and as best shown in FIGS. 5, 20A and 26A, the diffuser 36 is located near the hosel region 26 from the toe 20, toe 20 and back 22 intersection, and / or back. Can extend toward 22. The cross-sectional area of the diffuser 36 can gradually increase as the diffuser 36 extends away from the hosel region 26. Any reverse pressure gradient that increases in the airflow flowing from the hosel region 26 toward the tow 20 and / or the back 22 is expected to be mitigated by an increase in the cross-sectional area of the diffuser 36. Accordingly, it is expected that any transition from laminar to turbulent regime of air flowing over sole 28 will be delayed and even completely eliminated. In certain configurations, the sole 28 may include a plurality of diffusers.

One or more diffusers 36 may be directed to mitigate drag during at least some portion of the downswing stroke, particularly as the club head 14 rotates about the yaw axis. The side surface of the diffuser 36 can be straight or curved. In certain configurations, the diffuser 36 may be oriented at an angle from Y ₀ axis for diffusing air flow (ie reducing the adverse pressure gradient) when hosel region 26 and / or heel 24 is to lead the swing is there. Diffuser 36 may be oriented at an angle in the range of Y ₀ axis of about 10 ° ~ about 80 °. In some cases, the diffuser 36 has an angle in the range of about 20 ° to about 70 °, or about 30 ° to about 70 °, or about 40 ° to about 70 °, or even about 45 ° to about 65 ° from the T ₀ direction. May be suitable. Thus, in certain configurations, the diffuser 36 can extend from the hosel region 26 toward the toe 20 and / or the back surface 22. In other configurations, the diffuser 36 may extend from the heel 24 toward the toe 20 and / or the back surface 22.

  In some cases, the diffuser 36 may include one or more vanes 32, as shown in FIGS. The blades 32 can be positioned approximately at the center between the side surfaces of the diffuser 36. In a particular configuration (not shown), the diffuser 36 can include a plurality of vanes. In other configurations, the diffuser 36 need not include vanes. Further, the vanes 32 can extend substantially along the entire length of the diffuser 36 or only partially along the length of the diffuser 36.

  As shown in FIGS. 1-4 and 6, according to one embodiment, the club head 14 may include a “come back” feature 23. The comeback feature 23 can extend from the crown 18 to the sole 28. As shown in FIGS. 3 and 6, the comeback feature 23 extends across the back surface 22 from the heel 24 to the toe 20. Further, as shown in FIGS. 2 and 4, the comeback feature 23 can extend into the toe 22 and / or into the heel 24.

  In general, the comeback feature uses laminar flow that can be maintained with a very long and gradually tapered downstream end (or rear end) of an aerodynamically shaped body, but with a shorter tapered downstream end. It is designed taking into account that it cannot be maintained. If the tapered downstream end is too short to maintain laminar flow, the turbulent drag may begin to become significant after the downstream end of the club head cross-sectional area has been reduced to approximately 50 percent of the club head maximum cross section. is there. This drag can be mitigated by trimming or removing the taper downstream end of the club head that is too short rather than maintaining a taper end that is too short. This relatively steep cut at the tapered end is referred to as a comeback feature 23.

  As discussed above, the heel 24 and / or hosel region 26 leads the swing during a significant portion of the golfer's downswing. During these portions of the downswing, either the tow 20, a portion of the tow 20, the intersection of the tow 20 and the back surface 22, and / or a portion of the back surface 22 forms the downstream or rear end of the club head 14. (See, eg, FIGS. 27 and 29-31). Thus, the comeback feature 23 reduces turbulence during these portions of the downswing when positioned along the toe of the club head 14, at the intersection of the toe 20 and the back 22 and / or along the back 22 And therefore can be expected to reduce drag due to turbulence.

  In addition, during the golfer's final downswing of approximately 20 ° before the collision with the golf ball, the back surface 22 of the club head 14 is aligned in the downstream direction of the airflow as the ball striking face 17 begins to lead the swing. Become. Therefore, the comeback feature 23, when placed along the back surface 22 of the club head 14, is expected to most significantly reduce turbulence during the final approximately 20 ° golfer downswing, and thus reduce drag due to turbulence. Is done.

  According to certain aspects, the comeback feature 23 may include a continuous groove 29 formed in a portion of the periphery of the club head 14. The groove 29 extends completely from the front portion 30 of the tow 20 to the rear edge 32 of the tow 20 and continues to the rear portion 22 as shown in FIGS. The groove 29 then extends across the entire length of the back surface 22. As can be seen in FIG. 4, the groove 29 tapers toward the end of the rear portion 34 of the heel 24. In a particular embodiment (see FIG. 2), the groove 29 in the front portion 30 of the tow 20 can turn around and continue along a portion of the sole 28.

  In the exemplary embodiment of FIGS. 2-4, the groove 29 is substantially U-shaped. In certain embodiments, groove 29 has a maximum depth (D) of about 15 mm. However, it should be appreciated that the groove 29 can have any depth along its length, and that the depth of the groove 29 can vary along its length. Furthermore, the groove 29 can have any height (H), but a maximum height from the maximum sole to crown of the club head 14 can be one to one half and most advantageous. It should be recognized that. The height of the groove 29 can vary over its length as shown in FIGS. 2-4, or the height of the groove 29 can be uniform over part or all of its length.

  As the air flows over the crown 18 and sole 28 of the body member 15 of the club head 14, it tends to separate, which causes increased drag. The groove 29 can help reduce drag and reduce the aerodynamics of the club head 14 by reducing the tendency of the air to separate, thereby moving the ball after hitting the club head speed and The distance increases. As described above, since the leading portion of the club head 14 is the heel 24 and the rear edge of the club head 14 is the toe 20 in the majority of the swing path of the golf club head 14, the groove 29 extends along the toe 20. It can be particularly advantageous to extend the Thus, the aerodynamic advantage provided by the groove 29 along the tow 20 is realized during the majority of the swing trajectory. The portion of the groove 29 extending along the back surface 22 can provide an aerodynamic advantage at the point of impact of the club head 14 with the ball.

An example of the drag reduction during the swing given by the groove 29 is shown in the following table. This table is based on a computer fluid dynamics (CFD) model of the club head 14 embodiment shown in FIGS. In the table, drag values at different yaw angles during a golf swing are shown for both the square head design and the square head design that includes the drag reduction structure of the groove 29.

  From the result of the computer model, it can be understood that the drag of the square club head with the groove 29 is about 48.2% (4.01 / 8.32) of the square club head at the collision point where the yaw angle is 0 °. However, the total drag integral during the entire square club head swing shows a total drag of 544.39, while the square club head with groove 29 has a total drag of 216.75. Thus, the total drag of a square club head with grooves 29 is approximately 39.8% (216.75 / 544.39) of the total drag of the square club head. Therefore, by integrating the drag of the entire swing, a result that is very different from the case of calculating the drag only at the collision point can be generated.

  With reference to FIGS. 7-10, a continuous groove 29 is formed in a portion of the periphery of the club head 54. The groove 29 extends completely from the front portion 30 of the tow 20 to the rear edge 32 of the tow 20 and continues to the rear portion 22 as shown in FIGS. The groove 29 then extends across the entire length of the rear portion 22. As can be seen in FIG. 9, the groove 29 tapers toward the end of the rear portion 34 of the heel 24.

  One or more drag reduction structures, such as the streamlined portion 100 of the heel 24, to reduce drag against the club head during the user's golf swing through a downswing from the end of the user's backswing to the ball impact location. The diffuser 36 of the sole 28 and / or the cam back structure 23 can be provided on the club head 14. In particular, the streamlined portion 100 of the heel 24, the diffuser 36, and the heel 24 to reduce drag on the club head 14 as the heel 24 and / or hosel region 26 of the club head 14 generally leads the swing. A comeback feature 23 can be provided. The cam-back structure 23, particularly when disposed within the back surface 22 of the club head 14, can also be provided to reduce drag on the club head 14 when the ball striking surface 17 generally leads the swing.

  Different golf clubs are designed according to different proficiency levels that the player exhibits in the game. For example, a professional player may choose a club that is very efficient in converting the energy generated during a swing into the energy of flying a golf ball over a very small sweet spot. In contrast, weekend players may choose a club that is designed to allow less than perfect placement of the club's sweet spot relative to the golf ball hit. To provide these different club characteristics, club heads having any of various weights, volumes, moments of inertia, center of gravity placement, stiffness, face (ie, hitting ball surface) height, width, and / or area, etc. to the club Can be provided.

A typical modern driver club head may be provided with a volume ranging from about 420 cc to about 470 cc. The club head volume presented herein is measured using USGA "Procedure for Measuring the Club Head Size of Wood Clubs" (November 21, 2003). A typical driver club head weight can range from about 190 g to about 220 g. Referring to FIGS. 32A and 32B, other physical properties of a typical driver can be defined and characterized. For example, the face area can range from about 3000 mm ² ~ about 4800 mm ^2, to the face length can range from about 110mm~ about 130 mm, the face height can range from about 48mm~ about 62 mm. The face area is defined as the area bounded by the inner tangent of the radius area that combines the ball striking surface with the other part of the body member of the golf club head. As shown in FIG. 32B, the face length is measured from the opposite point on the club head. Face height is measured when the club is positioned at a lie angle of 60 degrees with respect to a zero degree face angle, and is measured at the face center (see USGA, “Procedure for Measuring the Flexibility of a Golf ClubHead, "Section 6.1 Determination of Impact Location), defined as the distance from the ground plane to the midpoint of the radius area that combines the ball striking face and crown of the club. The club head width can range from about 105 mm to about 125 mm. Moment of inertia at the center of gravity about an axis parallel to the X ₀ axis can range from about 2800 g-cm ² ~ about 3200 g-cm ^2. The moment of inertia at the center of gravity about an axis parallel to the Z ₀ axis can range from about 4500 g-cm ² to about 5500 g-cm ² . In a typical modern driver, the club head's X ₀ centroid location (measured from the ground zero point) can range from about 25 mm to about 33 mm, and the Y ₀ centroid location can be from about 16 mm to It can range from about 22 mm (also measured from ground zero point) and, (measured from again ground zero point) Z ₀ direction of the center of gravity of the place where about 25mm~ can range from about 38mm.

The values presented above for the specific characteristic parameters of a typical modern driver club head are not intended to be limiting. Thus, for example, in certain embodiments, the club head volume can exceed 470 cc and the club head weight can exceed 220 g. In certain embodiments, the moment of inertia at the center of gravity about an axis parallel to the X ₀ axis can exceed 3200 g-cm ^2. For example, the moment of inertia at the center of gravity about an axis parallel to the X ₀ axis is maximum 3400 g-cm ^2, the maximum 3600 g-cm ^2, more can range exceeding or it maximum 4000 g-cm ^2. Similarly, in certain embodiments, the moment of inertia at the center of gravity about an axis parallel to the Z ₀ axis may exceed 5500 g-cm ² . For example, the maximum 5700 g-cm ² moment of inertia at the center of gravity about the axis parallel to the Z ₀ axis, maximum 5800 g-cm ^2, more can range up to 6000 g-cm ^2.

  Any given golf club design always encompasses a series of trade-offs or compromises. The aspects disclosed below illustrate some of these tradeoffs.

Exemplary Embodiment (1)
In the first example, a representative embodiment of the club head shown in FIGS. 1-6 will be described. This first exemplary club head is provided with a volume of greater than about 400 cc. Referring to FIGS. 32A and 32B, other physical properties can be characterized. The face height ranges from about 53 mm to about 57 mm. Moment of inertia at the center of gravity about an axis parallel to the X ₀ axis is in the range of about 2800 g-cm ² ~ about 3300 g-cm ^2. The moment of inertia at the center of gravity about an axis parallel to the Z ₀ axis is greater than about 4800 g-cm ² . As an indicator of club aspect ratio, the club width to face length ratio is 0.94 or more.

Further, the club head of this first exemplary embodiment can have a weight in the range of about 200 g to about 210 g. Referring to FIGS. 32A and 32B again, to face length can range from about 114mm~ about 118 mm, the face area can range from about 3200 mm ² ~ about 3800 mm ^2. The club head width can range from about 112 mm to about 114 mm. The location of the center of gravity of X ₀ can range from about 28 mm to about 32 mm, the location of the center of gravity in the Y ₀ direction can range from about 17 mm to about 21 mm, and the location of the center of gravity in the Z ₀ direction can be from about 27 mm to about 31 mm. (Both measured from the ground zero point).

  For this exemplary club head, Table I shows a set of nominal spline point coordinates for the upper curve 113 and the lower curve 114 of the cross section 110. As discussed, in some cases, these nominal spline point coordinates can vary within a range of ± 10%.

(Table I) Spline point of section 110 in example (1)

Alternatively, by using the Bezier equations (1a) and (1b) presented above for this exemplary club head, the x and z coordinates of the upper curve 113 of the cross section 110 can be obtained as follows:
x _u = 3 (17) (1-t) t ² + (48) t ³ (113a)
z _u = 3 (10) (1-t) ² t + 3 (26) (1-t) t ² + (26) t ³ formula (113b)
Range: 0 ≦ t ≦ 1
Therefore, for this particular curve 113, the x coordinate Bezier control points are defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 17 and Px _u3 = 48, and the z coordinate Bezier control points are Pz _u0 = 0 , Pz _u1 = 10, Pz _u2 = 26 and Pz _u3 = 26. As discussed, in some cases these z-coordinates can vary within a range of ± 10%.

Similarly, by using Bezier equations (2a) and (2b) for this exemplary club head, the x and z coordinates of the lower curve 114 of the cross-section 110 can be obtained as follows:
x _L = 3 (11) (1-t) t ² + (48) t ³ (114a)
z _L = 3 (-10) (1-t) ² t + 3 (-26) (1-t) t ² + (-32) t ³ formula (114b)
Range: 0 ≦ t ≦ 1
Therefore, for this particular curve 114, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 11 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = -10, Pz _L2 = -26 and Pz _L3 = -32. In some cases, these z coordinates may also vary within a range of ± 10%.

From a review of the data and drawings, it can be appreciated that the upper crown side curve 113 is different from the lower sole side curve 114. For example, at 3 mm along the x axis from the tip point 112, the lower curve 114 has a z coordinate value that is approximately 40% greater than the z coordinate value of the upper curve 113. This introduces an initial asymmetry to the curve, i.e., the lower curve 114 begins at a depth greater than the upper curve 113. However, from 3mm to 24mm along the x-axis, both the upper curve 113 and the lower curve 114 both extend a further 15mm away from the x-axis (ie Δz _U = 22-7 = 15mm and Δz _L = 25-10 = 15mm) . Also, from 3 mm to 36 mm along the x axis, the upper curve 113 and the lower curve 114 extend further 18 mm and 19 mm away from the x axis, respectively, which is a difference of less than 10%. In other words, the curves of the upper curve 113 and the lower curve 114 are substantially the same at 3 mm to 36 mm along the x axis.

Referring now to FIG. 30A, the upper and lower curves 123 and 124 of this first exemplary club head are presented as a table of spline points, respectively, similar to the curves 113 and 114 discussed above with respect to FIG. 29A. Can be characterized by a curve. Table II shows a set of spline point coordinates for the cross section 120 of Example (1). The z _U coordinate is associated with the upper curve 123 and the z _L coordinate is associated with the lower curve 124.

(Table II) Spline point of section 120 in example (1)

Alternatively, by using the Bezier equations (1a) and (1b) presented above for this exemplary club head, the x and z coordinates of the upper curve 123 of the cross-section 120 can be obtained as follows:
x _u = 3 (19) (1-t) t ² + (48) t ³ (123a)
z _u = 3 (10) (1-t) ² t + 3 (25) (1-t) t ² + (25) t ³ formula (123b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 123, the x-coordinate Bezier control point is defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 19 and Px _u3 = 48, and the z-coordinate Bezier control point is Pz _u0 = 0 , Pz _u1 = 10, Pz _u2 = 25 and Pz _u3 = 25.

As described above, by using Bezier equations (2a) and (2b) for this exemplary club head, the x and z coordinates of the lower curve 124 of the cross section 120 can be obtained as follows, respectively.
x _L = 3 (13) (1-t) t ² + (48) t ³ (124a)
z _L = 3 (-10) (1-t) ² t + 3 (-26) (1-t) t ² + (-30) t ³ formula (124b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 124, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 13 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = -10, Pz _L2 = -26 and Pz _L3 = -30.

From a review of the data and drawings, it can be appreciated that the upper crown side curve 123 is different from the lower sole side curve 124. For example, at 3 mm along the x-axis from the tip point 112, the lower curve 124 has a z coordinate value that is approximately 30% greater than the z coordinate value of the upper curve 123. This introduces an initial asymmetry to the curve. However, from 3mm to 18mm along the x-axis, the upper curve 123 and the lower curve 124 both extend a further 12mm away from the x-axis (ie Δz _U = 19-7 = 12mm and Δz _L = 21-9 = 12mm) . Also, from 3 mm to 24 mm along the x axis, the upper curve 123 and the lower curve 124 extend further 14 mm and 15 mm away from the x axis, respectively, which is a difference of less than 10%. In other words, the curves of the upper curve 123 and the lower curve 124 are substantially the same at 3 mm to 24 mm along the x axis.

Again, similar to the surfaces 113 and 114 discussed above, the upper and lower curves 133 and 134 can be characterized by curves presented as a table of spline points. Table III shows a set of spline point coordinates for the cross section 130 of Example (1). In this table, the coordinates of all spline points are defined relative to the tip point 112. The z _U coordinate is associated with the upper curve 133 and the z _L coordinate is associated with the lower curve 134.

(Table III) Spline points in section 130 of example (1)

Alternatively, using the Bezier equations (1a) and (1b) presented above for this exemplary club head, the x and z coordinates of the upper curve 133 of the cross-section 130 can be obtained as follows:
x _u = 3 (25) (1-t) t ² + (48) t ³ (133a)
z _u = 3 (10) (1-t) ² t + 3 (21) (1-t) t ² + (18) t ³ formula (133b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 133, the x coordinate Bezier control points are defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 25 and Px _u3 = 48, and the z coordinate Bezier control points are Pz _u0 = 0 , Pz _u1 = 10, Pz _u2 = 21 and Pz _u3 = 18.

As described above, by using Bezier equations (2a) and (2b) for this exemplary club head, the x and z coordinates of the lower curve 134 of the cross section 130 can be obtained as follows, respectively.
x _L = 3 (12) (1-t) t ² + (48) t ³ (134a)
z _L = 3 (-10) (1-t) ² t + 3 (-22) (1-t) t ² + (-29) t ³ formula (134b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 134, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 12 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = -10, Pz _L2 = -22 and Pz _L3 = -29.

  Analysis of the data of this example (1) aspect at the cross-section 130 shows that at 3 mm along the x-axis from the tip point 112, the lower sole side curve 134 is approximately 30% of the z coordinate value of the upper crown side curve 133. Indicates that it has a large z coordinate value. This introduces an initial asymmetry to the curve. From 3 mm to 18 mm along the x axis, the upper curve 133 and the lower curve 134 extend further 9 mm and 12 mm away from the x axis, respectively. In fact, from 3 mm to 12 mm along the x axis, the upper curve 133 and the lower curve 134 extend further 6 mm and 8 mm away from the x axis, respectively, which is a difference of more than 10%. In other words, the curvatures of the upper curve 133 and the lower curve 134 in the embodiment (1) are significantly different over the target range. Further, by looking at FIG. 31A, it can be recognized that the upper curve 133 is flatter (the bending is smaller) than the lower curve 134.

  In addition, if you compare the curve of section 110 (ie, a section that faces 90 degrees from the centerline) with the curve of section 120 (that is, a section that faces 70 degrees from the centerline), you can see that they are very similar. . Specifically, in the x coordinate of 3 mm, 6 mm, 12 mm and 18 mm, the z coordinate value of the upper curve 113 is the same as the z coordinate value of the upper curve 123, and then the z coordinate value of the upper curves 113 and 123. Are less than 10% apart from each other. With respect to the lower curves 114 and 124 of the cross-sections 110 and 120, respectively, the z coordinate values deviate by 10% or less from each other over the x coordinate range of 0 mm to 48 mm, and the lower curve 124 is slightly smaller than the lower curve 114. When comparing the curve of section 110 (that is, 90 degrees from the centerline) with the curve of section 130 (that is, 45 degrees from the centerline), the lower curve of section 130 over the x-coordinate range of 0 mm to 48 mm It can be seen that the z-coordinate value of 134 differs from the z-coordinate value of the lower curve 114 of the cross-section 110 by a substantially constant amount of 2 mm or 3 mm. On the other hand, it can be recognized that the difference between the z-coordinate value of the upper curve 133 of the cross-section 130 and the z-coordinate value of the upper curve 113 of the cross-section 110 increases over the x-coordinate range of 0 mm to 48 mm. In other words, the curve of the upper curve 133 is significantly different from the curve of the upper curve 113, and the upper curve 133 is significantly flatter than the upper curve 113. This can also be recognized by comparing curve 113 in FIG. 29A and curve 133 in FIG. 31A.

Exemplary Embodiment (2)
In the second example, a representative embodiment of the club head shown in FIGS. This second exemplary club head is provided with a volume of greater than about 400 cc. The face height ranges from about 56 mm to about 60 mm. Moment of inertia at the center of gravity about an axis parallel to the X ₀ axis is in the range of about 2600 g-cm ² ~ about 3000 g-cm ^2. The moment of inertia at the center of gravity about an axis parallel to the Z ₀ axis ranges from about 4500 g-cm ² to about 5200 g-cm ² . The club width to face length ratio is greater than 0.90.

Further, the club head of this second exemplary embodiment can have a weight in the range of about 197 g to about 207 g. Referring to FIGS. 32A and 32B again, to face length can range from about 122mm~ about 126 mm, the face area can range from about 3200 mm ² ~ about 3800 mm ^2. The club head width can range from about 112 mm to about 116 mm. It X ₀ direction of the center of gravity of the place can range from about 28mm~ about 32 mm, to Y ₀ direction of the center of gravity of the place can range from about 17mm~ about 21 mm, Z ₀ direction of the center of gravity location about 33mm~ about It can be in the range of 37mm (both measured from the ground zero point).

  For the club head of this example (2), Table IV shows a set of nominal spline point coordinates for the upper and lower curves of section 110. As already discussed, in some cases these nominal spline point coordinates can vary within a range of ± 10%.

(Table IV) Spline point of section 110 in example (2)

Alternatively, by using the Bezier equations (1a) and (1b) presented above for this exemplary club head, the x and z coordinates of the upper curve 113 of the cross section 110 can be obtained as follows:
x _u = 3 (22) (1-t) t ² + (48) t ³ formula (213a)
z _u = 3 (8) (1-t) ² t + 3 (23) (1-t) t ² + (23) t ³ formula (213b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 113, the x coordinate Bezier control points are defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 22 and Px _u3 = 48, and the z coordinate Bezier control points are Pz _u0 = 0 , Pz _u1 = 8, Pz _u2 = 23 and Pz _u3 = 23. As discussed, in some cases these z-coordinates can vary within a range of ± 10%.

Similarly, by using Bezier equations (2a) and (2b) for this exemplary club head, the x and z coordinates of the lower curve 114 of the cross-section 110 can be obtained as follows:
x _L = 3 (18) (1-t) t ² + (48) t ³ (214a)
z _L = 3 (-12) (1-t) ² t + 3 (-25) (1-t) t ² + (-33) t ³ formula (214b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 114, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 18 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = -12, Pz _L2 = -25 and Pz _L3 = -33. In some cases, these z coordinates may also vary within a range of ± 10%.

From the examination of the data of the aspect (2) in the cross section 110, the lower curve 114 has a z coordinate value 50% larger than the z coordinate value of the upper curve 113 at 3 mm along the x axis from the tip point 112. I understand that. This introduces an initial asymmetry to the curve. However, from 3 mm to 24 mm along the x-axis, the upper curve 113 extends an additional 13 mm away from the x-axis (ie Δz _U = 19−6 = 13 mm) and the lower curve 114 extends an additional 15 mm away from the x-axis (ie Δz _L = 24-9 = 15mm). Also, from 3 mm to 36 mm along the x axis, the upper curve 113 and the lower curve 114 extend further 16 mm and 21 mm away from the x axis, respectively. In other words, the upper curve 113 is flatter than the lower curve 114 at 3 mm to 36 mm along the x-axis.

Referring now to FIG. 30A, the upper and lower curves 123 and 124 of this second exemplary club head are presented as a table of spline points, similar to the curves 113 and 114 discussed above with respect to FIG. 29A. It can be characterized by a curve. Table V shows a set of spline point coordinates for the cross section 120 of Example (2). In this table, the spline point coordinates are defined as values for the tip point 112. The z _U coordinate is associated with the upper curve 123 and the z _L coordinate is associated with the lower curve 124.

(Table V) Spline point of section 120 in example (2)

Alternatively, by using the Bezier equations (1a) and (1b) presented above for this exemplary club head, the x and z coordinates of the upper curve 123 of the cross-section 120 can be obtained as follows:
x _u = 3 (28) (1-t) t ² + (48) t ³ (223a)
z _u = 3 (9) (1-t) ² t + 3 (22) (1-t) t ² + (21) t ³ formula (223b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 123, the x-coordinate Bezier control point is defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 28 and Px _u3 = 48, and the z-coordinate Bezier control point is Pz _u0 = 0 , Pz _u1 = 9, Pz _u2 = 22 and Pz _u3 = 21.

As described above, by using Bezier equations (2a) and (2b) for this exemplary club head, the x and z coordinates of the lower curve 124 of the cross section 120 can be obtained as follows, respectively.
x _L = 3 (13) (1-t) t ² + (48) t ³ (224a)
z _L = 3 (-11) (1-t) ² t + 3 (-22) (1-t) t ² + (-33) t ³ formula (224b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 124, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 13 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = -11, Pz _L2 = -22 and Pz _L3 = -33.

In the cross section 120, the lower curve 124 has a z coordinate value that is 50% larger than the z coordinate value of the upper curve 123 at 3 mm along the x axis from the tip point 112. This introduces an initial asymmetry to the curve. However, from 3 mm to 24 mm along the x axis, the upper curve 123 extends a further 11 mm away from the x axis (ie Δz _U = 17−6 = 11 mm) and the lower curve 124 extends a further 15 mm away from the x axis (ie Δz _L = 24-9 = 15mm). Also, from 3 mm to 36 mm along the x-axis, the upper curve 123 and the lower curve 124 further extend away from the x-axis by 14 mm and 20 mm, respectively. In other words, similar to the curve of the cross section 110, the upper curve 123 is flatter than the lower curve 124 at 3 mm to 36 mm along the x-axis.

Similar to surfaces 113 and 114 discussed above, upper and lower curves 133 and 134 can be characterized by curves presented as a table of spline points. Table VI shows a set of spline point coordinates for the cross-section 130 of Example (2). In this table, the coordinates of all spline points are defined relative to the tip point 112. The z _U coordinate is associated with the upper curve 133 and the z _L coordinate is associated with the lower curve 134.

(Table VI) Spline point in section 130 of example (2)

Alternatively, using the Bezier equations (1a) and (1b) presented above for this exemplary club head, the x and z coordinates of the upper curve 133 of the cross-section 130 can be obtained as follows:
x _u = 3 (26) (1-t) t ² + (48) t ³ (233a)
z _u = 3 (9) (1-t) ² t + 3 (14) (1-t) t ² + (13) t ³ formula (233b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 133, the x coordinate Bezier control points are defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 26 and Px _u3 = 48, and the z coordinate Bezier control points are Pz _u0 = 0 , Pz _u1 = 9, Pz _u2 = 14 and Pz _u3 = 13.

As described above, by using Bezier equations (2a) and (2b) for this exemplary club head, the x and z coordinates of the lower curve 134 of the cross section 130 can be obtained as follows, respectively.
x _L = 3 (18) (1-t) t ² + (48) t ³ (234a)
z _L = 3 (-7) (1-t) ² t + 3 (-23) (1-t) t ² + (-30) t ³ formula (234b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 134, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 18 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = -7, Pz _L2 = -23 and Pz _L3 = -30.

In cross section 130, at 3 mm along the x-axis from tip point 112, lower curve 134 has a z coordinate value that is only 20% greater than the z coordinate value of upper curve 133. This introduces an initial asymmetry to the curve. From 3 mm to 24 mm along the x-axis, the upper curve 133 extends further 7 mm away from the x-axis (ie Δz _U = 17−6 = 7 mm) and the lower curve 134 extends further 15 mm away from the x-axis (ie Δz _L = 21-6 = 15mm). Also, from 3 mm to 36 mm along the x axis, the upper curve 133 and the lower curve 134 extend further 8 mm and 20 mm away from the x axis, respectively. In other words, the upper curve 133 is significantly flatter than the lower curve 134 at 3 mm to 36 mm along the x-axis.

  Furthermore, in the embodiment of this example (2), when comparing the curve of the cross section 110 (ie, the cross section facing 90 degrees from the center line) with the curve of the cross section 120 (ie, the cross section facing 70 degrees from the center line), they are similar. Can recognize that Specifically, the z-coordinate value of the upper curve 113 differs from the z-coordinate value of the upper curve 123 by about 10% or less. With respect to the lower curves 114 and 124 of the cross-sections 110 and 120, respectively, the z coordinate values deviate by less than 10% from each other over the x coordinate range of 0 mm to 48 mm, and the lower curve 124 is slightly smaller than the lower curve 114. When comparing the curve in this example (2) of section 110 (i.e. a section facing 90 degrees from the center line) with the curve of section 130 (i.e. a section facing 45 degrees from the center line), the x coordinate between 0 mm and 48 mm It can be appreciated that over the range, the z-coordinate value of the lower curve 134 of the cross-section 130 differs from the z-coordinate value of the lower curve 114 of the cross-section 110 by a substantially constant amount of 3 mm or 4 mm. On the other hand, it can be recognized that the difference between the z coordinate value of the upper curve 133 of the cross section 130 and the z coordinate value of the upper curve 113 of the cross section 110 increases steadily over the x coordinate range of 0 mm to 48 mm. In other words, the curve of the upper curve 133 is significantly different from the curve of the upper curve 113, and the upper curve 133 is significantly flatter than the upper curve 113.

Exemplary Embodiment (3)
In a third example, a representative embodiment of the club head shown in FIGS. 15-20 will be described. This third exemplary club head is provided with a volume greater than about 400 cc. The face height ranges from about 52 mm to about 56 mm. Moment of inertia at the center of gravity about an axis parallel to the X ₀ axis is in the range of about 2900 g-cm ² ~ about 3600 g-cm ^2. The moment of inertia at the center of gravity about an axis parallel to the Z ₀ axis is greater than about 5000 g-cm ² . The club width to face length ratio is greater than 0.94.

This third exemplary club head can also be provided with a weight that can range from about 200 g to about 210 g. Referring to FIGS. 32A and 32B, the face length can range from about 122 mm to about 126 mm, and the face area can range from about 3300 mm ² to about 3900 mm ² . The club head width can range from about 115 mm to about 118 mm. It X ₀ direction of the center of gravity of the place can range from about 28mm~ about 32 mm, to Y ₀ direction of the center of gravity of the place can range from about 16mm~ about 20 mm, Z ₀ direction of the center of gravity location about 29mm~ about It can be in the range of 33mm (all measured from the ground zero point).

  For the club head of this example (3), Table VII shows a set of nominal spline point coordinates for the upper and lower curves of section 110. As already discussed, in some cases these nominal spline point coordinates can vary within a range of ± 10%.

(Table VII) Spline point of section 110 in example (3)

Alternatively, by using the Bezier equations (1a) and (1b) presented above for this exemplary club head, the x and z coordinates of the upper curve 113 of the cross section 110 can be obtained as follows:
x _u = 3 (17) (1-t) t ² + (48) t ³ (313a)
z _u = 3 (5) (1-t) ² t + 3 (12) (1-t) t ² + (11) t ³ formula (313b)
Range: 0 ≦ t ≦ 1
Therefore, for this particular curve 113, the x coordinate Bezier control points are defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 17 and Px _u3 = 48, and the z coordinate Bezier control points are Pz _u0 = 0 , Pz _u1 = 5, Pz _u2 = 12 and Pz _u3 = 11. As discussed, in some cases these z-coordinates can vary within a range of ± 10%.

Similarly, by using Bezier equations (2a) and (2b) for this exemplary club head, the x and z coordinates of the lower curve 114 of the cross-section 110 can be obtained as follows:
x _L = 3 (7) (1-t) t ² + (48) t ³ (314a)
z _L = 3 (-15) (1-t) ² t + 3 (-32) (1-t) t ² + (-44) t ³ formula (314b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 114, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 7 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = -15, Pz _L2 = -32 and Pz _L3 = -44. In some cases, these z coordinates may also vary within a range of ± 10%.

From the examination of the data of the aspect of this example (3) in the cross section 110, the lower curve 114 has a z coordinate value 275% larger than the z coordinate value of the upper curve 113 at 3 mm along the x axis from the tip point 112. I understand that. This introduces an initial asymmetry to the curve. From 3 mm to 24 mm along the x axis, the upper curve 113 extends 6 mm further from the x axis (ie Δz _U = 10 −4 = 6 mm) and the lower curve 114 extends 19 mm further from the x axis (ie Δz _L = 34-15 = 19mm). Also, from 3 mm to 36 mm along the x axis, the upper curve 113 and the lower curve 114 extend further 7 mm and 25 mm away from the x axis, respectively. In other words, the upper curve 113 is significantly flatter than the lower curve 114 at 3 mm to 36 mm along the x-axis.

Referring now to FIG. 30A, the upper and lower curves 123 and 124 of this third exemplary club head are presented as a table of spline points, similar to the curves 113 and 114 discussed above with respect to FIG. 29A. It can be characterized by a curve. Table VIII shows a set of spline point coordinates for the cross section 120 of Example (3). In this table, the spline point coordinates are defined as values for the tip point 112. The z _U coordinate is associated with the upper curve 123 and the z _L coordinate is associated with the lower curve 124.

(Table VIII) Spline point of section 120 in example (3)

Alternatively, by using the Bezier equations (1a) and (1b) presented above for the club head of this example (3), the x-coordinate and z-coordinate of the upper curve 123 of the cross section 120 can be obtained as follows: Can do.
x _u = 3 (21) (1-t) t ² + (48) t ³ (323a)
z _u = 3 (5) (1-t) ² t + 3 (7) (1-t) t ² + (7) t ³ formula (323b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 123, the x-coordinate Bezier control point is defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 21 and Px _u3 = 48, and the z-coordinate Bezier control point is Pz _u0 = 0 , Pz _u1 = 5, Pz _u2 = 7 and Pz _u3 = 7.

As described above, by using Bezier equations (2a) and (2b) for this exemplary club head, the x and z coordinates of the lower curve 124 of the cross section 120 can be obtained as follows, respectively.
x _L = 3 (13) (1-t) t ² + (48) t ³ (324a)
z _L = 3 (-18) (1-t) ² t + 3 (-34) (1-t) t ² + (-43) t ³ formula (324b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 124, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 13 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = −18, Pz _L2 = −34 and Pz _L3 = −43.

In the cross section 120 of the example (3), the lower curve 124 has a z coordinate value 250% larger than the z coordinate value of the upper curve 123 at 3 mm along the x axis from the tip point 112. This introduces an initial asymmetry to the curve. From 3 mm to 24 mm along the x axis, the upper curve 123 extends a further 3 mm away from the x axis (ie Δz _U = 7−4 = 3 mm) and the lower curve 124 extends a further 20 mm away from the x axis (ie Δz _L = 34-14 = 20mm). Further, at 3 mm to 36 mm along the x-axis, the upper curve 123 and the lower curve 124 further extend away from the x-axis by 3 mm and 25 mm, respectively. In other words, similar to the curve of the cross-section 110, the upper curve 123 is significantly flatter than the lower curve 124 at 3 mm to 36 mm along the x-axis. In fact, from 24 mm to 48 mm, the upper curve 123 maintains a constant distance from the x-axis, while the lower curve 124 is further 9 mm apart over this same range.

Similar to surfaces 113 and 114 discussed above, upper and lower curves 133 and 134 can be characterized by curves presented as a table of spline points. Table IX shows a set of spline point coordinates for the cross section 130 of Example (3). In this table, the coordinates of all spline points are defined relative to the tip point 112. The z _U coordinate is associated with the upper curve 133 and the z _L coordinate is associated with the lower curve 134.

(Table IX) Spline point of section 130 in example (3)

Alternatively, using the Bezier equations (1a) and (1b) presented above for this exemplary club head, the x and z coordinates of the upper curve 133 of the cross-section 130 can be obtained as follows:
x _u = 3 (5) (1-t) t ² + (48) t ³ formula (333a)
z _u = 3 (6) (1-t) ² t + 3 (5) (1-t) t ² + (-2) t ³ formula (333b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 133, the x coordinate Bezier control points are defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 5 and Px _u3 = 48, and the z coordinate Bezier control points are Pz _u0 = 0 , Pz _u1 = 6, Pz _u2 = 5 and Pz _u3 = -2.

As described above, by using Bezier equations (2a) and (2b) for the club head of this example (3), the x coordinate and the z coordinate of the lower curve 134 of the cross section 130 can be obtained as follows: it can.
x _L = 3 (18) (1-t) t ² + (48) t ³ (334a)
z _L = 3 (-15) (1-t) ² t + 3 (-32) (1-t) t ² + (-41) t ³ formula (334b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 134, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 18 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = -15, Pz _L2 = -32 and Pz _L3 = -41.

In the cross section 130 of the example (3), the lower curve 134 has a z coordinate value 175% larger than the z coordinate value of the upper curve 133 at 3 mm along the x axis from the tip point 112. This introduces an initial asymmetry to the curve. From 3 mm to 24 mm along the x-axis, the upper curve 133 extends −2 mm away from the x-axis (ie Δz _U = 2−4 = −2 mm). In other words, the upper curve 133 was actually close to the x-axis over this range. On the other hand, the lower curve 134 extends a further 19 mm away from the x axis (ie Δz _L = 30-11 = 19 mm). Also, from 3 mm to 36 mm along the x-axis, the upper curve 133 and the lower curve 134 further extend away from the x-axis by −4 mm and 26 mm, respectively. In other words, the upper curve 133 is significantly flatter than the lower curve 134 at 3 mm to 36 mm along the x-axis.

  Further, in the embodiment of this example (3), when comparing the curve of the section 110 (that is, the section facing 90 degrees from the center line) with the curve of the section 120 (that is, the section facing 70 degrees from the center line), the upper curve is While remarkably different, it can be recognized that the lower curves are very similar. Specifically, the value of the z coordinate of the upper curve 113 is different from the value of the z coordinate of the upper curve 123 by 57% (relative to the upper curve 123). The upper curve 123 is significantly flatter than the upper curve 113. With respect to the lower curves 114 and 124 of the cross-sections 110 and 120, respectively, the z coordinate values deviate by less than 10% from each other over the x coordinate range of 0 mm to 48 mm, and the lower curve 124 is slightly smaller than the lower curve 114. When comparing the curve in this example (3) of section 110 (ie 90 degrees from the centerline) to the curve of section 130 (ie 45 degrees from the centerline), the x coordinate between 0 and 48 mm It can be appreciated that over the range, the z-coordinate value of the lower curve 134 of the cross-section 130 differs from the z-coordinate value of the lower curve 114 of the cross-section 110 by a substantially constant amount of 3 mm or 4 mm. Accordingly, the curve of the lower curve 134 is substantially the same as the curve of the lower curve 114 over the x coordinate range of 0 mm to 48 mm with respect to the x axis. On the other hand, it can be recognized that the difference between the z coordinate value of the upper curve 133 of the cross section 130 and the z coordinate value of the upper curve 113 of the cross section 110 increases steadily over the x coordinate range of 0 mm to 48 mm. In other words, the curve of the upper curve 133 is significantly different from the curve of the upper curve 113, and the upper curve 133 is significantly flatter than the upper curve 113.

Exemplary Embodiment (4)
In a fourth example, representative aspects of the club head shown in FIGS. This fourth exemplary club head is provided with a volume greater than about 400 cc. The face height ranges from about 58 mm to about 63 mm. Moment of inertia at the center of gravity about an axis parallel to the X ₀ axis is in the range of about 2800 g-cm ² ~ about 3300 g-cm ^2. The moment of inertia at the center of gravity about an axis parallel to the Z ₀ axis ranges from about 4500 g-cm ² to about 5200 g-cm ² . The club width to face length ratio is greater than 0.94.

In addition, this fourth exemplary club head is provided with a weight that can range from about 200 g to about 210 g. Referring to FIGS. 32A and 32B, to the face length can range from about 118mm~ about 122 mm, the face area can range from about 3900mm ² ~4500mm ^2. The club head width can range from about 116 mm to about 118 mm. It X ₀ direction of the center of gravity of the place can range from about 28mm~ about 32 mm, to Y ₀ direction of the center of gravity of the place can range from about 15mm~ about 19 mm, Z ₀ direction of the center of gravity location about 29mm~ about It can be in the range of 33mm (all measured from the ground zero point).

  For the club head of this example (4), Table X shows a set of nominal spline point coordinates for the heel side of cross section 110. These spline point coordinates are shown as absolute values. As discussed, in some cases, these nominal spline point coordinates can vary within a range of ± 10%.

(Table X) Spline point of section 110 in example (4)

Alternatively, by using the Bezier equations (1a) and (1b) presented above for the club head of this example (4), the x-coordinate and z-coordinate of the upper curve 113 of the cross section 110 can be obtained as follows: Can do.
x _u = 3 (31) (1-t) t ² + (48) t ³ (413a)
z _u = 3 (9) (1-t) ² t + 3 (21) (1-t) t ² + (20) t ³ formula (413b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 113, the x coordinate Bezier control points are defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 31 and Px _u3 = 48, and the z coordinate Bezier control points are Pz _u0 = 0 , Pz _u1 = 9, Pz _u2 = 21 and Pz _u3 = 20. As discussed, in some cases these z-coordinates can vary within a range of ± 10%.

Similarly, by using Bezier equations (2a) and (2b) for this exemplary club head, the x and z coordinates of the lower curve 114 of the cross-section 110 can be obtained as follows:
x _L = 3 (30) (1-t) t ² + (48) t ³ (414a)
z _L = 3 (-17) (1-t) ² t + 3 (-37) (1-t) t ² + (-40) t ³ formula (414b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 114, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 30 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = -17, Pz _L2 = -37 and Pz _L3 = -40. In some cases, these z coordinates may also vary within a range of ± 10%.

From the examination of the data of the embodiment (4) in the cross-section 110, the lower curve 114 has a z coordinate value 100% larger than the z coordinate value of the upper curve 113 at 3 mm along the x-axis from the tip point 112. I understand that. This introduces an initial asymmetry to the curve. From 3 mm to 24 mm along the x-axis, the upper curve 113 extends further 11 mm away from the x-axis (ie Δz _U = 16 −5 = 11 mm) and the lower curve 114 extends further 20 mm away from the x-axis (ie Δz _L = 30-10 = 20mm). Also, from 3 mm to 36 mm along the x axis, the upper curve 113 and the lower curve 114 extend further 14 mm and 26 mm away from the x axis, respectively. In other words, the upper curve 113 is significantly flatter than the lower curve 114 at 3 mm to 36 mm along the x-axis.

Referring now to FIG. 30A, the upper and lower curves 123 and 124 of this first exemplary club head are presented as a table of spline points, similar to the curves 113 and 114 discussed above with respect to FIG. 29A. It can be characterized by a curve. Table XI shows a set of spline point coordinates for the cross section 120 of Example (4). In this table, the spline point coordinates are defined relative to the tip point 112. The z _U coordinate is associated with the upper curve 123 and the z _L coordinate is associated with the lower curve 124.

(Table XI) Spline point of section 120 in example (4)

Alternatively, by using the Bezier equations (1a) and (1b) presented above for the club head of this example (4), the x-coordinate and z-coordinate of the upper curve 123 of the cross section 120 can be obtained as follows: Can do.
x _u = 3 (25) (1-t) t ² + (48) t ³ formula (423a)
z _u = 3 (4) (1-t) ² t + 3 (16) (1-t) t ² + (14) t ³ formula (423b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 123, the x-coordinate Bezier control point is defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 25 and Px _u3 = 48, and the z-coordinate Bezier control point is Pz _u0 = 0 , Pz _u1 = 4, Pz _u2 = 16 and Pz _u3 = 14.

As described above, by using Bezier equations (2a) and (2b) for this exemplary club head, the x and z coordinates of the lower curve 124 of the cross section 120 can be obtained as follows, respectively.
x _L = 3 (26) (1-t) t ² + (48) t ³ (424a)
z _L = 3 (-18) (1-t) ² t + 3 (-36) (1-t) t ² + (-41) t ³ formula (424b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 124, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 26 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = -18, Pz _L2 = -36 and Pz _L3 = -41.

In the cross section 120 of the example (4), the lower curve 124 has a z coordinate value that is 175% larger than the z coordinate value of the upper curve 123 at 3 mm along the x axis from the tip point 112. This introduces an initial asymmetry to the curve. From 3 mm to 24 mm along the x-axis, the upper curve 123 extends a further 8 mm away from the x-axis (ie Δz _U = 12−4 = 8 mm) and the lower curve 124 extends a further 20 mm away from the x-axis (ie Δz _L = 31-11 = 20mm). In addition, from 3 mm to 36 mm along the x axis, the upper curve 123 and the lower curve 124 further extend away from the x axis by 10 mm and 26 mm, respectively. In other words, similar to the curve of the cross-section 110, the upper curve 123 is significantly flatter than the lower curve 124 at 3 mm to 36 mm along the x-axis.

Similar to surfaces 113 and 114 discussed above, upper and lower curves 133 and 134 can be characterized by curves presented as a table of spline points. Table XII shows a set of spline point coordinates for the cross section 130 of Example (4). In this table, the coordinates of all spline points are defined relative to the tip point 112. The z _U coordinate is associated with the upper curve 133 and the z _L coordinate is associated with the lower curve 134.

(Table XII) Spline point of section 130 in example (4)

Alternatively, using the Bezier equations (1a) and (1b) presented above for this exemplary club head, the x and z coordinates of the upper curve 133 of the cross-section 130 can be obtained as follows:
x _u = 3 (35) (1-t) t ² + (48) t ³ formula (433a)
z _u = 3 (6) (1-t) ² t + 3 (9) (1-t) t ² + (5) t ³ formula (433b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 133, the x coordinate Bezier control points are defined as Px _u0 = 0, Px _u1 = 0, Px _u2 = 35 and Px _u3 = 48, and the z coordinate Bezier control points are Pz _u0 = 0 , Pz _u1 = 6, Pz _u2 = 9 and Pz _u3 = 5.

As described above, by using Bezier equations (2a) and (2b) for the club head of this example (4), the x coordinate and the z coordinate of the lower curve 134 of the cross section 130 can be obtained as follows: it can.
x _L = 3 (40) (1-t) t ² + (48) t ³ (434a)
z _L = 3 (-17) (1-t) ² t + 3 (-35) (1-t) t ² + (-37) t ³ Formula (434b)
Range: 0 ≦ t ≦ 1
Thus, for this particular curve 134, the x coordinate Bezier control points are defined as Px _L0 = 0, Px _L1 = 0, Px _L2 = 40 and Px _L3 = 48, and the z coordinate Bezier control points are Pz _L0 = 0 , Pz _L1 = −17, Pz _L2 = −35 and Pz _L3 = −37.

In the cross section 130 of the example (4), the lower curve 134 has a z coordinate value 100% larger than the z coordinate value of the upper curve 133 at 3 mm along the x axis from the tip point 112. This introduces an initial asymmetry to the curve. From 3 mm to 24 mm along the x-axis, the upper curve 133 extends 3 mm away from the x-axis (ie Δz _U = 7−4 = 3 mm). The lower curve 134 extends a further 18 mm away from the x axis (ie Δz _L = 26-8 = 18 mm). Also, from 3 mm to 36 mm along the x-axis, the upper curve 133 and the lower curve 134 extend further 3 mm and 24 mm away from the x-axis, respectively. In other words, the upper curve 133 is significantly flatter than the lower curve 134 at 3 mm to 36 mm along the x-axis.

  Furthermore, in the embodiment of this example (4), when comparing the curve of the cross section 110 (ie, the cross section facing 90 degrees from the center line) with the curve of the cross section 120 (ie, the cross section facing 70 degrees from the center line), the upper curve is While remarkably different, it can be recognized that the lower curves are very similar. Specifically, the z-coordinate value of the upper curve 113 differs from the z-coordinate value of the upper curve 123 by a maximum of 43% (relative to the upper curve 123). The upper curve 123 is significantly flatter than the upper curve 113. With respect to the lower curves 114 and 124 of the cross-sections 110 and 120, respectively, the z coordinate values deviate by less than 10% from each other over the x coordinate range of 0 mm to 48 mm, and the lower curve 124 is slightly smaller than the lower curve 114. When comparing the curve in this example (4) of section 110 (i.e. 90 degrees from the centerline) with the curve of section 130 (i.e. 45 degrees from the centerline), the x coordinate between 0 mm and 48 mm It can be seen that over the range, the z-coordinate value of the lower curve 134 of the cross-section 130 differs from the z-coordinate value of the lower curve 114 of the cross-section 110 in the range of 2 mm to 4 mm. Therefore, in the embodiment (4), the curve of the lower curve 134 is slightly different from the curve of the lower curve 114. On the other hand, over the x-coordinate range of 0 mm to 48 mm, the difference between the z-coordinate value of the upper curve 133 of the cross-section 130 and the z-coordinate value of the upper curve 113 of the cross-section 110 steadily increases from a difference of 1 mm to a difference of 15 mm. You can recognize that In other words, the curve of the upper curve 133 is significantly different from the curve of the upper curve 113, and the upper curve 133 is significantly flatter than the upper curve 113.

  Given the benefits of this disclosure, streamlined regions 100 that are smoothed in the same manner as sections 110, 120, 130 have the same drag reduction as the specific sections 110, 120, 130 defined by Tables I-XII. It will be apparent to those skilled in the art that the benefits of Accordingly, the cross-sections 110, 120, 130 presented in Tables I-XII can be enlarged or reduced to accommodate various sized club heads. Furthermore, given the benefits of this disclosure, streamline regions 100 having upper and lower curves that substantially match the upper and lower curves defined by Tables I-XII are also listed in Tables I-XII. It will be apparent to those skilled in the art that the same drag reduction benefits are generally realized with the particular upper and lower curves presented. Thus, for example, the z-coordinate values can differ from the z-coordinate values presented in Tables I-XII by up to ± 5%, up to ± 10%, and in some cases up to ± 15%.

  While basic novel features of various aspects have been shown, described and pointed out, it will be apparent to those skilled in the art that the form and details of the apparatus illustrated and the various omissions, substitutions and modifications of their operation are within the spirit and scope of the present invention. It will be understood that this can be done without departing from the scope. For example, the golf club head can be any driver, wood, etc. Moreover, it is expressly intended that all combinations of elements that perform substantially the same function in substantially the same way to achieve the same result are within the scope of the invention. Substitution of elements from one described embodiment to another is also fully contemplated and contemplated. Accordingly, it is intended that the scope of the claims appended hereto be limited only by the instructions.

Claims (34)

A golf club head for a driver having a volume of 400 cc or more and a club width to face length ratio of 0.90 or more,
A body member further comprising a leading edge within the heel defined as a surface of the heel having a crown, a sole and a heel and having a vertical bevel when the club head is in a 60 degree lie angle position. A body member further comprising a first cross section including a tip point located on the leading edge, a first crown side surface extending from the tip point, and a first sole side surface extending from the tip point. Including
The first cross section is oriented perpendicular to the center line of the club head;
The tip point represents the origin of a _first x ₁ and z ₁ coordinate system oriented in the plane of the first cross section at a roll angle of about 15 °, and the first crown side surface is defined by the spline point Stipulated:

z A golf club head whose _1U coordinates can vary ± 10%. The first sole side surface is defined by the following spline points:

2. The golf club head according to claim 1, wherein the z _1L coordinate can vary ± 10%. The body member further has a second cross section including a tip point located on the leading edge, a second crown side surface extending from the tip point, and a second sole side surface extending from the tip point. ,
The second cross section is oriented approximately 70 ° from the center line of the club head;
The tip point further represents the origin of a _second x ₂ and z ₂ coordinate system oriented in the plane of the second cross section at a roll angle of about 15 °, and the second crown side surface is the spline point Specified by:

2. The golf club head according to claim 1, wherein the z _2U coordinate can vary ± 10%. The second sole side surface is defined by the following spline points:

_4. The golf club head according to claim 3, wherein the z _2L coordinate can vary ± 10%. The body member further has a second cross section including a tip point located on the leading edge, a second crown side surface extending from the tip point, and a second sole side surface extending from the tip point. ,
The second cross section is oriented approximately 45 ° from the center line of the club head;
Further representing the origin of a _second x ₂ and z ₂ coordinate system, wherein the tip point is in the plane of the second cross section at a roll angle of about 15 °;
The second crown side surface is defined by the following spline points:

z _2U coordinates can vary ± 10%, and the second sole side surface is defined by the following spline points:

2. The golf club head according to claim 1, wherein the z _2L coordinate can vary ± 10%. The body member is configured to be attached to a shaft having a longitudinal axis, and the tip point is located from about 15 mm to about 25 mm from the longitudinal axis of the shaft;
2. The golf club head according to claim 1. The body member is configured to be attached to a shaft having a longitudinal axis, and the tip point is located about 20 mm from the longitudinal axis of the shaft;
2. The golf club head according to claim 1.   The golf club head of claim 1, wherein the body member further includes a groove extending at least partially along a horizontal length of the tow and extending at least partially along the horizontal length of the back surface.   2. The golf club head according to claim 1, having a volume of 420 cc or more.   2. The golf club head according to claim 1, having a face height of 53 mm or more.   The golf club head of claim 1, having a club width to face length ratio of 0.92 or greater. A golf club head for a driver having a volume of 400 cc or more and a club width to face length ratio of 0.90 or more,
A body member further comprising a leading edge within the heel defined as a surface of the heel having a crown, a sole and a heel and having a vertical bevel when the club head is in a 60 degree lie angle position. A body further comprising a first cross section including a tip point located on the leading edge, a first crown side surface curve extending from the tip point, and a first sole side surface curve extending from the tip point Including members,
The first cross section is oriented perpendicular to the center line of the club head;
Tip endpoint, represents the origin of the first x ₁ and z ₁ coordinate system in the roll angle of approximately 15 ° oriented in the plane of said first section, and x ₁ and said first crown surface curve z ₁ coordinate is defined by the following Bezier equation:
x _1U = 3 (17) (1-t) t ² + (48) t ³
z _1U = 3 (10) (1-t) ² t + 3 (26) (1-t) t ² + (26) t ³
Range: 0 ≦ t ≦ 1
A golf club head in which the value of z _1U can vary ± 10%. The x ₁ and z ₁ coordinates of the first sole side surface curve are defined by the following Bezier equation:
x _1L = 3 (11) (1-t) t ² + (48) t ³
z _1L = 3 (-10) (1-t) ² t + 3 (-26) (1-t) t ² + (-32) t ³
Range: 0 ≦ t ≦ 1
13. The golf club head according to claim 12, wherein the value of z _1L can vary ± 10%. The body member further includes a second cross section including a tip point located on the leading edge, a second crown side surface curve extending from the tip point, and a second sole side surface curve extending from the tip point. Have
The second cross section is oriented approximately 70 ° from the center line of the club head;
The tip point further represents the origin of a _second x ₂ and z ₂ coordinate system oriented in the plane of the second cross section at a roll angle of about 15 °, and x _{2U of the} second crown side surface curve And z _2U coordinates are defined by the following Bezier equation:
x _2U = 3 (19) (1-t) t ² + (48) t ³
z _2U = 3 (10) (1-t) ² t + 3 (25) (1-t) t ² + (25) t ³
Range: 0 ≦ t ≦ 1
13. The golf club head according to claim 12, wherein the value of z _2U can vary ± 10%. The x _1L and z _1L coordinates of the second sole side surface curve are defined by the following Bezier equation:
x _2L = 3 (13) (1-t) t ² + (48) t ³
z _2L = 3 (-10) (1-t) ² t + 3 (-26) (1-t) t ² + (-30) t ³
Range: 0 ≦ t ≦ 1
_15. The golf club head according to claim 14, wherein the value of z _2L can vary ± 10%. The body member is configured to be attached to a shaft having a longitudinal axis, and the tip point is located from about 15 mm to about 25 mm from the longitudinal axis of the shaft;
13. A golf club head according to claim 12. The body member is configured to be attached to a shaft having a longitudinal axis, and the tip point is located about 20 mm from the longitudinal axis of the shaft;
13. A golf club head according to claim 12.   13. A golf club head according to claim 12, wherein the body member further includes a groove extending at least partially along the length of the toe and extending at least partially along the length of the back surface.   13. The golf club head according to claim 12, wherein the club head has a volume of 420 cc or more and a club width to face length ratio of 0.92 or more. A body member having a ball striking surface, a crown, a toe, a heel, a sole, a back surface, and a hosel region located at an intersection of the ball striking surface, the heel, the crown and the sole,
Configured to be attached to a shaft having a longitudinal axis, including a tip point located on the heel from about 10 mm to about 30 mm from the longitudinal axis of the shaft;
Having a first cross section oriented approximately 90 ° from the center line of the club head;
A body member further having a second cross section oriented about 45 ° from the centerline of the club head;
Each of the first cross section and the second cross section includes a front end point located on the heel and has a crown side surface curve extending from the front end point and a sole side surface curve extending from the front end point. ,
The first cross section has a first airfoil curve in the heel and a first concave surface opposite the heel, and the second cross section is a second airfoil in the heel; A golf club head having an airfoil curvature and a second concave surface opposite the heel. Tip point, represent the origin of the first x ₁ and z ₁ coordinate system in the roll angle of approximately 15 ° facing the first plane of section, and the first crown surface curve is defined by the following spline points :

_21. A golf club head according to claim 20, wherein the value of the z _1U coordinate can vary ± 10%. The first sole side surface curve is defined by the following spline points:

_21. A golf club head according to claim 20, wherein the value of the z _1L coordinate can vary ± 10%. The tip point further represents the origin of the second x ₂ and z ₂ coordinate system with a roll angle of about 15 ° in the plane of the second cross section, and the second crown side surface curve is defined by the spline point below Is:

_21. A golf club head according to claim 20, wherein the value of the z _2U coordinate can vary ± 10%. The second sole side surface curve is defined by the following spline points:

_24. A golf club head according to claim 23, wherein the value of the z _2L coordinate can vary ± 10%.   21. A golf club head according to claim 20, wherein the tip point is located about 15 mm to about 25 mm from the longitudinal axis of the shaft.   21. A golf club head according to claim 20, wherein the tip point is located about 20 mm from the longitudinal axis of the shaft.   The first concave surface and the second concave surface are formed by continuous grooves extending at least partially along the length of the tow and at least partially along the length of the back surface. 20. A golf club head according to 20. A golf club head for a driver having a volume of 400 cc or more and a club width to face length ratio of 0.90 or more,
A body member further comprising a leading edge within the heel defined as a surface of the heel having a crown, a sole and a heel and having a vertical bevel when the club head is in a 60 degree lie angle position. A body member further comprising a first cross section including a tip point located on the leading edge, a first crown side surface extending from the tip point, and a first sole side surface extending from the tip point. Including
The first cross section is oriented perpendicular to the center line of the club head;
The tip point represents the origin of a _first x ₁ and z ₁ coordinate system oriented in the plane of the first cross section at a roll angle of about 15 °, and the first crown side surface is defined by the spline point Stipulated:

z _1U coordinates can vary ± 10% and the first sole side surface is defined by the following spline points:

z A golf club head whose _1L coordinates can vary ± 10%. A golf club head for a driver having a volume of 400 cc or more and a club width to face length ratio of 0.90 or more,
A body member further comprising a leading edge within the heel defined as a surface of the heel having a crown, a sole and a heel and having a vertical bevel when the club head is in a 60 degree lie angle position. A body further comprising a first cross section including a tip point located on the leading edge, a first crown side surface curve extending from the tip point, and a first sole side surface curve extending from the tip point Including members,
The first cross section is oriented perpendicular to the center line of the club head;
Tip endpoint, represents the origin of the first x ₁ and z ₁ coordinate system in the roll angle of approximately 15 ° oriented in the plane of said first section, and x ₁ and said first crown surface curve z ₁ coordinate is defined by the following Bezier equation:
x _1U = 3 (22) (1-t) t ² + (48) t ³
z _1U = 3 (8) (1-t) ² t + 3 (23) (1-t) t ² + (23) t ³
Range: 0 ≦ t ≦ 1
And the value of z _1U can vary ± 10%, and the x ₁ and z ₁ coordinates of the _first sole-side surface curve are defined by the following Bezier equation:
x _1L = 3 (18) (1-t) t ² + (48) t ³
z _1L = 3 (-12) (1-t) ² t + 3 (-25) (1-t) t ² + (-33) t ³
Range: 0 ≦ t ≦ 1
z A golf club head whose _1L value can vary ± 10%. A golf club head for a driver having a volume of 400 cc or more and a club width to face length ratio of 0.90 or more,
A body member further comprising a leading edge within the heel defined as a surface of the heel having a crown, a sole and a heel and having a vertical bevel when the club head is in a 60 degree lie angle position. A body member further comprising a first cross section including a tip point located on the leading edge, a first crown side surface extending from the tip point, and a first sole side surface extending from the tip point. Including
The first cross section is oriented perpendicular to the center line of the club head;
The tip point represents the origin of a _first x ₁ and z ₁ coordinate system oriented in the plane of the first cross section at a roll angle of about 15 °, and the first crown side surface is defined by the spline point Stipulated:

z _1U coordinates can vary ± 10% and the first sole side surface is defined by the following spline points:

z A golf club head whose _1L coordinates can vary ± 10%. A golf club head for a driver having a volume of 400 cc or more and a club width to face length ratio of 0.90 or more,
A body member further comprising a leading edge within the heel defined as a surface of the heel having a crown, a sole and a heel and having a vertical bevel when the club head is in a 60 degree lie angle position. A body further comprising a first cross section including a tip point located on the leading edge, a first crown side surface curve extending from the tip point, and a first sole side surface curve extending from the tip point Including members,
The first cross section is oriented perpendicular to the center line of the club head;
Tip endpoint, represents the origin of the first x ₁ and z ₁ coordinate system in the roll angle of approximately 15 ° oriented in the plane of said first section, and x ₁ and said first crown surface curve z ₁ coordinate is defined by the following Bezier equation:
x _1U = 3 (17) (1-t) t ² + (48) t ³
z _1U = 3 (5) (1-t) ² t + 3 (12) (1-t) t ² + (11) t ³
Range: 0 ≦ t ≦ 1
And the value of z _1U can vary ± 10%, and the x ₁ and z ₁ coordinates of the _first sole-side surface curve are defined by the following Bezier equation:
x _1L = 3 (7) (1-t) t ² + (48) t ³
z _1L = 3 (-15) (1-t) ² t + 3 (-32) (1-t) t ² + (-44) t ³
Range: 0 ≦ t ≦ 1
z A golf club head whose _1L value can vary ± 10%. A golf club head for a driver having a volume of 400 cc or more and a club width to face length ratio of 0.90 or more,
A body member further comprising a leading edge within the heel defined as a surface of the heel having a crown, a sole and a heel and having a vertical bevel when the club head is in a 60 degree lie angle position. A body member further comprising a first cross section including a tip point located on the leading edge, a first crown side surface extending from the tip point, and a first sole side surface extending from the tip point. Including
The first cross section is oriented perpendicular to the center line of the club head;
The tip point represents the origin of a _first x ₁ and z ₁ coordinate system oriented in the plane of the first cross section at a roll angle of about 15 °, and the first crown side surface is defined by the spline point Stipulated:

z _1U coordinates can vary ± 10% and the first sole side surface is defined by the following spline points:

z A golf club head whose _1L coordinates can vary ± 10%. A golf club head for a driver having a volume of 400 cc or more and a club width to face length ratio of 0.90 or more,
A body member further comprising a leading edge within the heel defined as a surface of the heel having a crown, a sole and a heel and having a vertical bevel when the club head is in a 60 degree lie angle position. A body further comprising a first cross section including a tip point located on the leading edge, a first crown side surface curve extending from the tip point, and a first sole side surface curve extending from the tip point Including members,
The first cross section is oriented perpendicular to the center line of the club head;
Tip endpoint, represents the origin of the first x ₁ and z ₁ coordinate system in the roll angle of approximately 15 ° oriented in the plane of said first section, and x ₁ and said first crown surface curve z ₁ coordinate is defined by the following Bezier equation:
x _1U = 3 (31) (1-t) t ² + (48) t ³
z _1U = 3 (9) (1-t) ² t + 3 (21) (1-t) t ² + (20) t ³
Range: 0 ≦ t ≦ 1
And the value of z _1U can vary ± 10%, and the x ₁ and z ₁ coordinates of the _first sole-side surface curve are defined by the following Bezier equation:
x _1L = 3 (30) (1-t) t ² + (48) t ³
z _1L = 3 (-17) (1-t) ² t + 3 (-37) (1-t) t ² + (-40) t ³
Range: 0 ≦ t ≦ 1
z A golf club head whose _1L value can vary ± 10%. 34. A golf club comprising a shaft and the golf club head of any one of claims 1, 12, 20, 28, 29, 30, 31, 32 and 33 secured to a first end of the shaft.

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