The present disclosure relates generally to a golf club head with a molded polymeric body.
A golf club may generally include a club head disposed on the end of an elongate shaft. During play, the club head may be swung into contact with a stationary ball located on the ground in an effort to project the ball in an intended direction and with a desired vertical trajectory.
Many design parameters must be considered when forming a golf club head. For example, the design must provide enough structural resilience to withstand repeated impact forces between the club and the ball, as well as between the club and the ground. The club head must conform to size requirements set by different rule setting associations, and the face of the club must not have a coefficient of restitution above a predefined maximum (measured according to applicable standards). Assuming that certain predefined design constraints are satisfied, a club head design for a particular loft can be quantified by the magnitude and location of the center of gravity, as well as the head's moment of inertia about the center of gravity and/or the shaft.
The club's moment of inertia relates to the club's resistance to rotation (particularly during an off-center hit), and is often perceived as the club's measure of “forgiveness.” In typical club designs, high moments of inertia are desired to reduce the club's tendency to push or fade a ball. Achieving a high moment of inertia generally involves moving mass as close to the perimeter of the club as possible (to maximize the moment of inertia about the center of gravity), and as close to the toe as possible (to maximize the moment of inertia about the shaft). In iron-type golf club heads, this desire for increased moments of inertia have given rise to designs such as the cavity-back club head and the hollow club head.
While the moment of inertia affects the forgiveness of a club head, the location of the center of gravity behind the club face (and above the sole) generally affects the trajectory of a shot for a given face loft angle. A center of gravity that is positioned as far rearward (away from the face) and as low (close to the sole) as possible typically results in a ball flight that has a higher trajectory than a club head with a center of gravity placed more forward and/or higher.
While a high moment of inertia is obtained by increasing the perimeter weighting of the club head or by moving mass toward the toe, an increase in the total mass/swing weight of the club head (i.e., the magnitude of the center of gravity) has a strong, negative effect on club head speed and hitting distance. Said another way, to maximize club head speed (and hitting distance), a lower total mass is desired; however a lower total mass generally reduces the club head's moment of inertia (and forgiveness).
In the tension between swing speed (mass) and forgiveness (moment of inertia), it may be desirable to place varying amounts of mass in specific locations throughout the club head to tailor a club's performance to a particular golfer or ability level. In this manner, the total club head mass may generally be categorized into two categories: structural mass and discretionary mass.
Structural mass generally refers to the mass of the materials that are required to provide the club head with the structural resilience needed to withstand repeated impacts. Structural mass is highly design-dependent, and provides a designer with a relatively low amount of control over specific mass distribution. On the other hand, discretionary mass is any additional mass that may be added to the club head design for the sole purpose of customizing the performance and/or forgiveness of the club. In an ideal club design, the amount of structural mass would be minimized (without sacrificing resiliency) to provide a designer with a greater ability to customize club performance, while maintaining a traditional or desired swing weight.
A golf club head includes a forward section and a body section. The forward section has a strike face, a frame that surrounds the strike face, and a flange extending from the frame. The body section is formed from a molded polymeric material, and includes a forward edge that defines a receiving portion adapted to receive the flange and a weight receiving feature spaced apart from the forward edge. The body section further includes a reinforcing structure protruding into the internal volume and extending between the weight receiving feature and the forward edge. The reinforcing structure is operative to transfer impact loads between the weight receiving feature and the metallic forward section, for example, during an impact between the strike face and a golf ball. In one configuration, the forward edge of the body section may be separated from the strike face by a distance of from about 15 mm to about 40 mm.
In one configuration, the flange is orthogonal to a reference plane, and has a width, measured orthogonally to the reference plane, of from about 3 mm to about 2 mm. Additionally, the flange may be adhered to the body section across a total surface area of from about 1300 mm2 to about 3000 mm2. The flange may further fully encircle an internal volume that is at least partially defined by the forward section and the body section.
The body section may be formed from a multi-component construction and may include a first polymeric portion and a second polymeric portion that are adhered together at a body seam to define an internal cavity. The first polymeric portion may include a body flange disposed along a portion of the body seam, and the second polymeric portion may include a second receiving portion adapted to receive the body flange. In this embodiment, when assembled, the body flange extends within the second receiving portion and is adhered to the second polymeric portion. In one configuration, the height of the body flange decreases as a function of an increasing distance from the forward edge.
The above features and advantages and other features and advantages of the present technology are readily apparent from the following detailed description when taken in connection with the accompanying drawings.
Referring to the drawings, wherein like reference numerals are used to identify like or identical components in the various views,
When the club head 10 is held in a neutral hitting position (i.e., where the shaft 16 is maintained entirely in a vertical plane and at a prescribed lie angle relative to a horizontal ground plane) the club head 10 may generally include a lower portion (i.e., a “sole 18”), an upper portion (i.e., a “crown 20”), and a hosel 22. For the purpose of this description, the crown 20 may meet the sole 18 where the surface has a vertical tangent (i.e., relative to the horizontal ground plane). The hosel 22 generally extends from the crown 20 and is configured to receive a shaft adapter or otherwise couple with the elongate shaft 16.
As generally illustrated in
The strike face 26 generally forms the leading surface of the club head 10 and has a slight convex/arcuate curvature that extends out from the club head 10. In one embodiment, the curvature (i.e., bulge and/or roll) of the strike face 26 has a radius of from about 7 inches to about 20 inches. Additionally, as is commonly understood, the strike face 26 may be disposed at an angle to a vertical plane when the club is held in a neutral hitting position. This angle may be generally referred to as the loft angle or slope of the club. Wood-type club heads (including hybrid woods), such as illustrated in
In one configuration, the frame 28 may include a swept-back sidewall portion 30 that extends away from the strike face 26. The sidewall portion 30 may form a portion of both the sole 18 and the crown 20, and may further include one or more surface profile features, such as an indented compression channel 32. The frame 28 may be rigidly attached to the strike face 26 either through integral manufacturing techniques, or through separate processes such as welding, brazing, or adhering.
In one configuration, to reduce the structural mass of the club head 10 beyond what is capable with traditional metal forming techniques, the body section 14 may be formed from a polymeric material and may be adhered to the forward section 12. The comparatively low density nature of polymeric materials also permits greater design flexibility, at less of a structural weight penalty, than similar designs made from metal. In one configuration, the desired design flexibility may be achieved by molding the polymeric material into shape using a molding technique, such as, injection molding, compression molding, blow molding, thermoforming or the like. To provide the maximum design flexibility, the preferred molding technique is injection molding.
While weight savings and design flexibility are important, the polymeric material must still be strong enough to withstand the stress that is experienced when the club head 10 impacts a ball. This may be accomplished through a combination of structural and material design choices. With regard to material selection, it is preferable to use a moldable polymeric material that has a tensile strength of greater than about 200 MPa (according to ASTM D638), or more preferably greater than about 250 MPa. Additionally, for ease of molding, if the polymeric material is filled, then the material should desirably have a resin content of greater than about 50%, or even greater than about 55% by weight. One such material may include, for example, a thermoplastic aliphatic or semi-aromatic polyamide that is filled with chopped fiber, such as chopped carbon fiber or chopped glass fiber. Other materials may include polyimides, polyamide-imides, polyetheretherketones (PEEK), polycarbonates, engineering polyurethanes, and/or other similar materials.
In general, while polymers may provide weight saving advantages, certain polymers, such as polyamides, may be difficult to reliably adhere due to their low surface energies. This may present a problem, for example, when attempting to secure the body section 14 to the forward section 12. The present design addresses this adhesion problem through the design of the interface/seam 24 between the forward section 12 and the body section 14. More specifically, the interface 24 incorporates a tongue-in-groove-style geometry to maximize contact area with the adhesive. By forming the interface 24 in this manner, the bond surface area is effectively doubled (i.e., opposing sides of a single flange), and the majority of the bond would experience predominantly sheer stress if removal were attempted (which has proven to provide a stronger bond than comparable joints relying on peel/tensile strength).
As shown in
In one configuration, the receiving portion may be defined by a forward edge 38 of the body section 14, and may resemble a continuous channel or groove. To promote easy assembly, the flange 34 is preferably oriented such that it is orthogonal to a reference plane 40, as shown in
In another embodiment, instead of the flange 34 being strictly orthogonal to the reference plane 40, the flange 34 may be pitched inwards by up to, for example, about 10 degrees. This pitch may be a fixed pitch, or may be variable such that the flange 34 is parallel to the body section 14 when inserted into the receiving portion 36. In this specific embodiment, the receiving portion may be, for example a channel that is dimensioned to accept the pitched flange, or may only be a single-sided receiving portion (e.g., similar to a lap joint) rather than a channel.
In one embodiment of the present design, an acceptable bond strength between the forward section 12 and the body section 14 may be achieved using a flange 34 that has a width 44, measured orthogonally to the reference plane 40, of from about 2 mm to about 8 mm (as shown in
As noted above, the highest stress concentrations during a club head impact are generally found near the strike face 26. To ensure that the polymeric body section 14 does not experience stress loads that exceed its design strength, the forward edge 38 of the body section 14 may be separated from the strike face 26 by a distance of from about 15 mm to about 40 mm when assembled. Said another way, the sidewall 30 of the forward section 12 may extend from the strike face 26 by a distance of from about 15 mm to about 40 mm. This distance may be sufficient to allow localized impact stresses to dissipate to a level that can be withstood by the polymer.
In one configuration, the body section 14 may be entirely molded through a single process. If complex geometries are desired, molding techniques such as lost core molding or injection molding with collapsible slides may be used to form any internal recesses or cavities. In another configuration, instead of a unitary design, the body section 14 may be formed as two or more portions that are subsequently joined together (i.e., shown in
With continued reference to
The various portions of the body section 14 may be affixed together using any suitable means, such as, for example, welding or gluing. Suitable welding methods may include stir welding, ultrasonic welding, or laser welding. If adhesive is used, the design of the joint may employ a similar tongue-in-groove-style joint as between the forward section 12 and the body section 14. Such a design promotes proper alignment, while also maximizing total bond surface area, and maximizing bond surface area that resists removal via sheer strength. In the embodiment shown in
At the most forward portion (i.e., closest to the forward edge 38 of the body section 14), such as shown in
Referring again to
In the design provided in
In one embodiment, one or more removable weight members may be selectively secured to the body section 14 for the purpose of modifying the center of gravity or moment of inertia of the club head 10. These removable weight members may alter the dynamics of the club head 10 throughout the swing and at impact, and provide a user with a desirable amount of post-purchase customization.
From a structural perspective, however, the inclusion of variably sized, localized masses can potentially impart large structural stresses throughout the swing in the proximity of the mass. To account for these stresses, in one configuration, one or more support flanges 80 may be positioned in a manner to buttress a localized mass (or weight-receiving feature configured to receive and retain the mass).
In one configuration, such as shown in
Other examples of weight receiving features 84 may include, for example, threaded openings, slider tracks, or cam-lock mechanisms that are adapted to receive at least a portion of the weighting member 86. Similarly, other examples of weighting members 86 may include masses that are adapted to, for example, screw into the receiving feature 84, lock into the receiving portion 84 (e.g., via a set screw or cam-lock mechanism), or be secured within the receiving portion using a threaded cap.
To further buttress the weight receiving feature 84, for example, if the weight receiving feature 84 is cantilevered into the internal volume 50, the body section 14 may include a reinforcing structure protruding into the internal volume 50 and extending between the weight receiving feature 84 and the forward edge 38. As shown, for example, in
The support flange 90 may extend from the sidewall 30 or frame 28 and may generally intersect the flange 34 at an angle of, for example, from about 80 degrees to about 100 degrees. Similar to the joints already described above, the support flange 90 may be secured/adhered to the body section 14 using a tongue-in-groove-style joint that maximizes bond surface area and prevents removal primarily via sheer strength.
More specifically, during assembly, the support flange 90 may be inserted and adhered within a corresponding receiving portion 92 formed by the reinforcing structure buttressing the weight receiving portion 84 of the body section 14. The receiving portion 92 may be a channel that is formed between two uniformly spaced walls/protruding ridges that are positioned to extend on opposing sides of the flange 90 when the forward section 12 is joined with the body section 14. In the illustrated embodiment, the support flange 90 and receiving portion 92 may be aligned such that the support flange 90 is operative to support the weight receiving feature 84 along the longitudinal axis of the weight tube, for example, during an impact with a golf ball.
While the present disclosure describes certain specific arrangements for the tongue-in-groove-style joints, these are meant for illustrative purposes only. For example, it would be equally possible for the body flange 68 to extend from the upper portion 60 of the body section 14 into a receiving portion 70 provided in the lower portion 62. Likewise, the support flange 80 may extend from the lower portion (and specifically from the weight receiving feature 84) and be adhered into a corresponding receiving portion 82/channel provided in the upper portion 60.
“A,” “an,” “the,” “at least one,” and “one or more” are used interchangeably to indicate that at least one of the item is present; a plurality of such items may be present unless the context clearly indicates otherwise. All numerical values of parameters (e.g., of quantities or conditions) in this specification, including the appended claims, are to be understood as being modified in all instances by the term “about” whether or not “about” actually appears before the numerical value. “About” indicates that the stated numerical value allows some slight imprecision (with some approach to exactness in the value; about or reasonably close to the value; nearly). If the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring and using such parameters. In addition, disclosure of ranges includes disclosure of all values and further divided ranges within the entire range. Each value within a range and the endpoints of a range are hereby all disclosed as separate embodiment. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated items, but do not preclude the presence of other items. As used in this specification, the term “or” includes any and all combinations of one or more of the listed items. When the terms first, second, third, etc. are used to differentiate various items from each other, these designations are merely for convenience and do not limit the items.
This is a continuation of U.S. patent application Ser. No. 17/014,887 filed Sep. 8, 2020, which is a continuation of U.S. patent application Ser. No. 16/122,620, filed on Sep. 5, 2018, and issued as U.S. Pat. No. 10,765,919 on Sep. 8, 2020, which is a continuation of U.S. application Ser. No. 15/793,852, filed on Oct. 25, 2017, and issued as U.S. Pat. No. 10,092,799 on Oct. 9, 2018, which is a continuation of U.S. application Ser. No. 14/724,328, filed on May 28, 2015, and issued as U.S. Pat. No. 9,833,666 on Dec. 5, 2017, all of which are hereby incorporated by reference in their entirety.
Number | Date | Country | |
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Parent | 17014887 | Sep 2020 | US |
Child | 17664698 | US | |
Parent | 16122620 | Sep 2018 | US |
Child | 17014887 | US | |
Parent | 15793852 | Oct 2017 | US |
Child | 16122620 | US | |
Parent | 14724328 | May 2015 | US |
Child | 15793852 | US |