JP2007125399A - Golf club head with top line insert - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a more forgiving and playable golf club head ideal for a golf beginner. <P>SOLUTION: A recess may be in the top line of the club head. An insert may be placed within the recess. The insert has a density that is less than the density of the club head body. The recess moves material from the club head, which in turn may increase the overall size of the club head, expand the size of the club head sweet spot, lower the club head center of gravity, and/or produce a greater club head moment of inertia. As an alternative to a recess, a thin protrusion may be provided at the top line of the club head and the insert provided with a corresponding groove to facilitate attachment. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a golf club, and more particularly to a golf club head having a top line recess with a lightweight insert.

  This application is a continuation-in-part of currently pending US patent application Ser. No. 10 / 843,622, filed on May 12, 2004, which is incorporated herein by reference in its entirety.

  Golf club heads come in many different forms and configurations, such as wood or metal types, iron types (including wedge type club heads), utility or special types, and putter types. Each of these styles has a predetermined function and configuration. The present invention relates to a golf club head having a substantially solid material region disposed near the top of the club head.

  Iron-type and utility-type golf club heads generally include a front face, that is, a hitting surface, a top line, and a sole. The front face touches the golf ball and hits the golf ball. A plurality of grooves, often called “score lines”, are provided in the face to help spin the ball. The top line is usually shaped to have a specific face to golfer and provide structural rigidity to the striking surface. A portion of the face can have different types of surface-treated areas that extend slightly beyond the score line. Some club heads have a surface treatment wrap at the top line. The golf club sole touches and interacts with the ground during the swing and is particularly important for golf shots.

  In a set of conventional iron-type golf clubs, each club includes a shaft with a club head attached to one end and a grip attached to the other end. The club head includes a face for hitting a golf ball. The angle between the face and the vertical plane is called the loft angle.

  The set typically includes irons, numbered 3 through 9, and a pitching wedge. One or more additional long irons, referred to as No. 1 or No. 2, and wedges such as lob wedges, gap wedges, sand wedges are added to the set depending on the situation. Each iron has a shaft length, but this shaft length usually decreases through the iron set as the loft of each club head increases as it transitions from a long iron to a short iron. The total weight of each club head increases through the set as the shaft length decreases from long irons to short irons. In order to properly ensure that each club maintains the same feel and balance during a golf swing, a measurement known as “swing weight” is used as a reference to define club head weight and shaft length. Often used. Each club in the set is typically designed to have an equal swing weight value for each different loft club head or each given shaft length, so that the weight of the club head Is limited to a certain range.

  The length of the shaft, along with the club head loft, moment of inertia, and center of gravity position, gives various performance characteristics to the launch state of the ball at impact, golf ball launch angle, spin speed, flight trajectory, and ball flight. Affects distance. The flight distance usually increases as the loft angle decreases. However, reducing the loft angle also increases the difficulty of use.

  Iron-type golf clubs can generally be classified into three types: blades and muscle backs, conventional cavity bags, and modern cavity bags made of composite materials. The blade is a traditional club with a nearly uniform appearance from the sole to the top line, but may taper somewhat from the sole to the top line. Similarly, the muscle back is nearly uniform, but has extra material in the back in the form of ribs that can be used to lower the club head's center of gravity. A club head having a center of gravity lower than the center of gravity of the ball facilitates raising the golf ball. Blade and muscle back designs are relatively difficult to master and are generally difficult to master, as the sweet spot is a term that refers to the face area that produces the desired golf shot when hitting a golf ball. Only use it. However, these designs allow a skilled golfer to work the ball and shape a golf shot as desired.

  A cavity back is a recent design that moves some of the mass of the club to the outer edge of the club by providing a hollow or cavity in the back of the club opposite the striking surface. This method results in a more tolerant club with a larger sweet spot. Having a larger sweet spot increases ease of use. The reduction in the mass of the club head due to the cavities also allows the club face size to be increased and also allows the sweet spot to be enlarged. The weighting of the perimeter created by the cavity also increases the club's moment of inertia, which is the magnitude of the club's resistance to torque, such as torque due to off-center hits. These clubs are easier to hit than blades and muscle backs and can therefore be used by novice golfers who are less skilled.

  A modern cavity back made of composite material is the latest attempt by golf club designers to make the cavity back more forgiving and easier to hit. Some of these designs replace certain areas of the club head, such as the striking surface or sole, with a second material that is heavier or lighter than the first material. These designs can also have deep undercuts or second cavities arising from the rear cavities. By incorporating different density materials or by providing cavities and undercuts, the overall size of the club head is increased, the sweet spot is increased, the moment of inertia is increased, and / or the center of gravity of the club head is increased. Mass can be used so that it can be optimized. However, some of these designs unintentionally thicken the top of the club head due to structural limitations and needs. Nonetheless, these improvements make the composite cavity back design the easiest style to strike among all styles and are well suited for less dexterous or novice golfers.

  As described above, play compatibility is increased by lowering the center of gravity of the club head. One way to lower the center of gravity is to lower the head face profile. However, this worsens the aesthetic appearance of the club head. Another way to lower the club's center of gravity is to lower the hosel height. However, if the hosel height is lowered, the moment of inertia is reduced (because the hosel's mass is away from the center of gravity), shaft coupling concerns, and it becomes impossible to customize the club head for loft / lie by bending. Disadvantages arise. Also, many golfers do not like the appearance of a club head with a very small hosel.

  The present invention relates to a golf club head having a body defining a front face, a top line, a sole, a back, a heel, a toe, and a hosel. The upper portion, preferably the top line, of the club head includes therein a recess located between the heel and toe and extending in the sole direction. This recess removes material from the club head and increases one or more of the following: increase the overall size of the club head, increase the size of the club head sweet spot, lower the club head center of gravity, and Provides the opportunity to produce a greater moment of inertia measured about a vertical or horizontal axis through the center of gravity of the club head. The golf club head in the present invention is preferably an iron type, utility type, or putter type golf club head.

  The insert formed of the second material can be placed in the recess. The insert has a density less than that of the club head body, and the insert is preferably a lightweight insert. This allows the mass removed from the recess to be relocated to a more desirable location on the club head, such as near the periphery and / or the sole. The insert can include one or more damping materials, such as viscoelastic materials, which also has the added value of dissipating vibrations that can occur during golf shots. The incorporation of this second material provides an improved feel and improved weight distribution and enhances club performance while still maintaining an aesthetically pleasing head shape. By incorporating this second material, the viscoelastic material covers the upper toe area of the club, which is mainly due to head scratches that can occur because the club collides with the club when the club is in the player's bag. Also, the wear of the head over time is improved.

  Instead of the recess, an extension may be provided on the upper part of the club head from which the relatively high-density metal material has been removed. The insert is attached to the extension.

The present invention will be described with reference to the accompanying drawings, wherein like reference numerals indicate like elements.
Except for working examples or unless otherwise stated, all numerical ranges, quantities, values, and percentages, such as amount of material, moment of inertia, center of gravity position, alignment, etc. The term “about” can be read as preceding, even if “about” does not appear in the expression for a value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following detailed description and claims are approximations that may vary depending upon the desired properties believed to be obtained by the present invention. It is. At a minimum, each numeric parameter is not intended to limit the applicability of the doctrine of equivalents to the claims, but at least in terms of the number of significant figures reported and applying normal rounding techniques. Should be interpreted.

  Although numerical ranges and parameters indicating the broad scope of the present invention are approximations, the numerical values shown in all specific examples are reported as accurately as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Further, when a variable range of numerical values is indicated herein, it is intended that any combination of these values, including the listed values, can be used.

  FIG. 1 is a plan view of a golf club head 1 of the present invention, and FIG. 2 is a front view of the golf club head 1. The golf club head 1 has a main body 10 that constitutes a front face 11, a top line 12, a sole 13, a back 14, a heel 15, a toe 16, and a hosel 17. The striking surface of the front face 11 and the sole 13 which are preferably provided with grooves 18 may be integral with the body 10 or may be separate bodies such as inserts which are coupled to the body 10. May be. Although the club head 1 is depicted as an iron type golf club head, the present invention is also suitable for a utility type golf club head or a putter type club head.

1 and 2 define a simplified coordinate system that helps to understand the orientation of the golf club head 1 and other terms discussed herein. Origin O is located at the intersection of the center line CL _SH and ground GP of the shaft, the ground GP is called the lie angle LA, defining a predetermined angle from the shaft center line CL _SH, sole at the lowest point of the sole 13 13 The X axis is defined as the vector projected onto the ground GP that is opposite to the orientation of the vector perpendicular to the face 11. The Y axis is defined as a vector that is perpendicular to the X axis and directed to the tow 16. The Z axis is defined as the cross product of the X axis and the Y axis.

The club head 1 has a recess 20 at the top, which is disposed between the heel 15 and the toe 16 and extends toward the sole 13. The recess 20 is disposed on the top line 12 of the club head 1 and preferably extends along the top line 12 by about 10% to 95% of the length of the top line. The length L _TL of the top line is defined as the distance from the point P ₁ to the point P ₂ along the top line 12. Point P ₁ is defined as the intersection of the golf club head 1 and a certain plane, which is defined by the X and Z axes and is on the toe 16 at the toe point furthest from the origin O along the Y axis. It is offset by 0.2 inches (L ₁ ) from the tangent plane and is parallel. The point P ₂ is defined as the uppermost intersection between the club head 1 and a certain plane. This plane is parallel to the plane formed by the shaft center line CL _SH and the X axis, and approaches the toe 16. The distance is offset by 0.3 inches (L ₂ ). The recess 20 removes material from the club head 1 and redistributes the material to other areas of the club head 1 to increase one or more of the following: the overall size of the club head 1 Increasing the size of the sweet spot of the club head, changing the position of the center of gravity of the club head (moving it to another position), and / or passing an axis parallel to the Y or Z axis through the center of gravity of the club head. This can be done by increasing the moment of inertia (MOI) measured at the center. Inertia is the property of a material that the object is stationary or in uniform motion unless affected by some external force. MOI is a measure of the resistance of an object to angular acceleration about a certain axis, and is equal to the sum of the product of each mass component of the object and the square of the distance of each component from the axis. Thus, as the mass distance from the axis increases, the MOI also increases and less energy is lost due to club head twisting on impact, making the club more tolerant of off-center hits. Can be made. Moving or rearranging the mass around the club head enlarges the sweet spot and creates a more forgiving club. Moving as much mass as possible to the outermost area of the club head 1 such as the heel 15, toe 16 or sole 13 maximizes the chance of expanding the sweet spot or creating a larger MOI. Recess 20 preferably has a volume of about 0.001 inch ³ to about 0.2 inch ³ . In comparative terms, the recess 20 preferably has a volume of about 0.5% to about 10% of the volume of the body 10. The recess 20 preferably has a depth D from about 0.01 inches to about 0.25 inches, which can be a constant depth or a varying depth.

An insert 30 is disposed in the recess 20. The insert 30, which may be a preformed insert or may be cast in place in the recess 20, is configured to closely match the recess 20. That is, the insert 30 is formed and shaped to fit the contour of the recess 20 and substantially fill the recess 20. As a variant, the insert 30 fills only a part of the recess 20. The insert 30 has a density lower than that of the club head body 10. Since the mass of the insert 30 is less than the mass removed by the recess 20, the extra or extra mass can be replaced with a more desirable position of the club head 1. These positions include, for example, the periphery of the club head and / or the sole 13. As a variation, additional mass may not be added to the club head 1. That is, only the recess 20 and the insert 30 may be used to enhance and enhance the play characteristics of the golf club. The insert 30 preferably has a density of about 0.5 g / cm ³ to about 5 g / cm ³ and is preferably at least 3 g / cm ³ lower than the density of the body. The net effect of forming the recess 20 and adding the insert 30 is that the center of gravity of the club head on the sole 13 is compared to the position of the center of gravity of the club head without the recess 20 and the insert 30 (CG ₂ in FIG. 4). To at least 0.01 inches down (CG ₁ in FIG. 4). That is, the golf club head 1 has a center of gravity located at least 0.01 inches from the center of gravity of a substantially similar golf club head without the recess 20 and the insert 30. More preferably, the center of gravity of the club head is lowered by at least 0.025 inches toward the sole 13. Also, the recess 20 and the insert 30 increase the MOI of the club head, measured about an axis parallel to the Z axis and passing through the center of gravity, by at least 20 gm · inch ² . That is, the club head 1 has an increase of at least 20 gm · in ² in a MOI measured about a vertical axis passing through the center of gravity as compared to a substantially similar golf club head without the recess 20 and the insert 30. Have. Thus, the recess 20 and the insert 30 create a golf club that is more forgiving and more playable. 5 and 6 show isometric views of the golf club head 1.

The insert 30 may contain one or more damping materials that reduce club head vibration, including vibrations that occur during off-center hits. Preferred damping materials include materials known as thermoplastic or thermosetting polymers such as rubber, urethane, polyurethane, butadiene, polybutadiene, silicone, and combinations thereof. During the impact, energy is transferred from the club to the ball. However, some energy is lost due to head vibration caused by impact. These vibrations provide an unpleasant sensation for the user in both feel and sound. Since the viscoelastic vibration damping material of the insert 30 is in direct contact with the metal club head (vibrating main body), it is useful for suppressing such vibration and improving sound and feel. Typical hardness values for the insert 30 include 80 Shore A to 50 Shore D. Typical densities for the insert 30 include 1.2 to 2 g / cm ³ .

  FIG. 7 shows a golf club head 2 according to another embodiment of the present invention, and FIG. 8 shows a cross section of the golf club head 2 taken along line 8-8. In this embodiment, material is removed from the metal club head at the top line 12. However, instead of forming a recess in the top line 12, a thin protrusion (projection) 19 is provided. The metal material is removed from the top of the club head as described above, leaving a thin extension 19 in place. The insert 30 has a groove corresponding to the convex portion 19. Therefore, the viscoelastic material can be fitted to the club head main body 10. The insert 30 is connected to a cast (casting) using, for example, epoxy. Using a fixture with a cavity that fits the shape of the outer periphery of the club head 1, the two parts should be held in place while the epoxy is dry. A preferable width A of the convex portion 19 is 0.06 inches, but a wider convex portion 19 can also be used. This width ensures sufficient structural integrity. Although the preferable height of the convex part 19 includes 0.06 inch to 0.25 inch, other heights may be used.

  The size of the metal parts of the club heads 1 and 2 may change during formation and polishing. These changes are generally larger than the size changes resulting from molding the viscoelastic material of the insert 30. To help hide any differences between the two parts of the club head, a groove 32 is formed at the edge of the insert 30 that is visible to the user when the two parts are assembled together. The groove 32 may be formed simultaneously with the remaining portion of the insert 30 or may be formed as a second step. The preferred width and depth of the groove 32 is 1 mm or less.

  7 and 8, the convex portion 19 is formed at the center of the top line 12. As a modified example, the convex portion 19 may be formed toward the front portion or the front portion of the top line 12, or toward the rear portion or the rear portion of the top line 12. The width B of the front part of the insert 30 may be zero in the sense that the convex part 19 forms the upper part of the face 11. As a modification, the width B may be 0.03 inch to 0.25 inch, for example. Similar to the width B, the width C of the rear portion of the insert 30 may be zero in the sense that the convex portion 19 forms the upper portion of the back 14. As a variation, the width C can be 0.03 inches to 0.25 inches, for example. The height of the insert 30 measured along the longest portion can preferably be 0.03 inches to 0.3 inches.

  The center of gravity of the main body is determined by its weight distribution. Mass directly added to or removed from the centroid does not affect the centroid position. In contrast, mass added or removed away from the center of gravity has a significant effect on the movement of the center of gravity. Moving the mass from the highest region of the club head has a significant effect on lowering the center of gravity. Adding the mass removed from the high area to the lower part of the club head further lowers the center of gravity. The top line area and the top area of the hosel are the two highest areas in the vertical direction in relation to the ground for the iron type head (when the head is in the address position). Depending on the design of the viscoelastic part, roughly 20 to 50 grams are removed from the top of the head by removing the topline part of the face from the molding (casting) and replacing it with a lighter viscoelastic part. . Such weight is redistributed to the lower part of the club, which allows a lower center of gravity relative to a similar club head made entirely of a metallic material such as steel.

  MOI is also a property that is affected by mass distribution. A body with mass distributed far from the center of gravity has a higher MOI around the center of gravity than a body with mass concentrated near the center of gravity. Removing mass from the top of the face lowers the MOI around the center of gravity for a particular axis. The axis of rotation involved in iron tolerance is the axis of rotation from the heel to the toe direction, centered on the center of gravity, parallel to the Z axis. A higher MOI around this axis indicates a greater resistance to torsion due to off-center hits and thus a greater tolerance. By removing the metal material from the top line 12 by adding the mass removed from the top line 12 back to the low heel and low toe regions of the club head, the reduction in MOI in the heel to toe direction is minimal. It becomes the limit.

Table 1 shows a comparison of the center of gravity and MOI for a No. 6 iron (head mass / 238.3 g) with a urethane insert 30 as shown in FIGS. 7 and 8 and a similar club head made entirely of steel. Represents. Note that the measurements shown in Table 1 do not include any weight that may be added to the club head.

Table 1

CG _x , CG _y , and CG _z are the x, y, and z components of the centroid position, respectively. I _xx , I _yy , and I _zz are MOIs about the x, y, and z axes, respectively. k is a spring constant.

  The use of the insert 30 as shown in FIGS. 7 and 8 has the additional advantage of increasing the durability of the club head 2. While playing, clubs carried together in a bag collide with each other. Such an impact damages the club head. The toe portion at the tip of the club is an area where impact is easily applied to other clubs. By making the area of a softer material, the risk of scratching the head due to a club-club collision is reduced.

  FIG. 9 shows a cross-sectional view of another golf club head 3 of the present invention with the toe portion removed. In this embodiment, the metal material is also removed from the top line 12 and replaced with a lightweight viscoelastic insert 30. The convex portion 19 is also provided in the club head 3, but unlike the club head 2 described above, it is directed rearward so as to be away from the face 11. The insert 30 includes a groove corresponding to the convex portion 19. Mounting is facilitated by the convex portion 19 and the groove. The metal face material extends to the top of the face 11 at the top line 12. As a variant, the viscoelastic material could extend below the top of the face 11, for example up to 0.3 inches.

  Although preferred embodiments of the present invention have been described above, it is to be understood that these embodiments are shown by way of example only and not limitation. It will be apparent to those skilled in the art that various modifications can be made in form and detail without departing from the spirit and scope of the invention. Therefore, the present invention should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

1 is a plan view of a golf club head of the present invention. It is a front view of the golf club head of FIG. FIG. 3 is a cross-sectional view of the golf club head of FIG. 1 taken along line 3-3. FIG. 3 is a cross-sectional view of the golf club head of FIG. 1 taken along line 3-3 with an insert. FIG. 2 is a first isometric view of the golf club head of FIG. 1. FIG. 3 is a second isometric view of the golf club head of FIG. 1. 3 is another golf club head of the present invention. FIG. 8 is a cross-sectional view taken along line 8-8 of the golf club head of FIG. 2 is a cross-sectional view of another golf club head of the present invention. FIG.

Claims (29)

A golf club head,
A body formed of a first material and comprising a front face, a sole, a back, a heel, a toe, and a top;
A convex portion provided on the top and extending away from the main body;
An insert formed of a second material connected to the convex portion,
Golf club head.   The golf club head according to claim 1, wherein the convex portion is located at a top line of the club head. The first material has a first density;
The second material has a second density;
The first density is greater than the second density;
The golf club head according to claim 1. The golf club head of claim 3, wherein the first density is at least 3 g / cm ³ greater than the second density. The golf club head of claim 3, wherein the second density is from 0.5 g / cm ³ to 5 g / cm ³ .   The golf club head according to claim 1, wherein the second material is a vibration damping material.   The golf club head according to claim 6, wherein the vibration damping material is a thermoplastic material or a thermosetting material. The damping material includes one or more of rubber, urethane, polyurethane, butadiene, polybutadiene, and silicon;
The golf club head according to claim 7.   The golf club head of claim 1, wherein the first material extends to an uppermost portion of the face at the top line.   The golf club head of claim 1, wherein the second material forms part of the face. The club head has a center of gravity;
The club head has a moment of inertia measured about a vertical axis through the center of gravity of at least 20 gm · inch as compared to a substantially similar golf club head in which the second material is replaced with the first material. ² increase,
The golf club head according to claim 1. The body has a first volume;
The insert has a second volume;
The second volume is 0.5% to 10% of the first volume;
The golf club head according to claim 1. A golf club head,
A body formed of a first material and comprising a front face, a sole, a back, a heel, a toe, and a top;
An insert formed of a second material having nylon and connected to the body at the top;
Golf club head. The top is provided with a convex portion extending away from the main body, and the insert is connected to the main body at the convex portion,
The golf club head according to claim 13.   The golf club head of claim 14, wherein the club head comprises a top line formed by the insert and a portion of the body.   The golf club head of claim 15, wherein all of the front face is formed of the first material.   The insert is made of reinforced nylon and has a tensile strength of 15 kpsi to 20 kpsi, a bending rate of 650 kpsi to 750 kpsi, a notch impact strength of 3 ft · Ib / inch to 4 ft · Ib / inch, and 73 ° at 50% relative humidity. 14. A golf club head according to claim 13, having a specific gravity of 1.25 to 2 when F is selected.   The golf according to claim 17, wherein the tensile strength is 17.5 kpsi, the bending rate is 600 kpsi, the notch impact strength is 3.5 ft · Ib / inch, and the specific gravity is 1.4. Club head.   The golf club head according to claim 13, wherein the sole includes an upper surface forming a recess between the heel and the toe.   The golf club head of claim 19, further comprising a second insert positioned within the recess, wherein the second insert is formed of a viscoelastic material.   The golf club head of claim 20, further comprising a weight member having a surface defining a second recess and connected to the second insert in the second recess.   21. A golf club head according to claim 20, further comprising a third insert coupled to the back opposite the front face, wherein the third insert is formed of a viscoelastic material.   14. A golf club head according to claim 13, comprising a second insert coupled to the back opposite the front face, wherein the second insert is formed of a viscoelastic material.   The golf club head of claim 13, comprising both a free layer damping system and a constrained layer damping system. The free layer vibration control system comprises a second insert coupled to the back opposite the front face;
The constraint layer damping system includes a third insert coupled to the upper surface of the sole, and a weight member coupled to the upper surface of the third insert.
25. A golf club head according to claim 24. The first material has a first density;
The second material has a second density;
The first density is greater than the second density;
The golf club head according to claim 13. The first of at least 3 g / cm ³ greater than the second density Density, golf club head according to claim 26. 28. A golf club head according to claim 27, wherein the second density is 0.5 g / cm < ³ > to 5 g / cm < ³ >.   The golf club head of claim 13, wherein the second material has a glass reinforcement of 25% to 50%.