In one aspect, the technology relates to a golf club head having: a crown; a club face connected to the crown; and a sole connected to and disposed opposite the crown, wherein the crown, the club face, and the sole at least partially define an interior void, and wherein at least one of the crown and the sole define at least one stranded structure, wherein an unsupported section of the at least one stranded structure is separated from at least one of the crown and the sole by a through-hole, and wherein the through-hole is filled with a vibration dampening material. In an embodiment, the stranded structure includes at least one of a cantilevered structure and a beam structure. In another embodiment, the vibration dampening material includes at least one of: an acrylic epoxy, a urethane, a polyurethane, an ionomer, an elastomer, a silicone, and a rubber. In yet another embodiment, at least one stranded structure is cantilevered and substantially spiral. In still another embodiment, the at least one stranded structure has a length to width ratio of at least ten.
In another embodiment of the above aspect, the vibration dampening material alters at least one of an inherent vibration frequency and an inherent vibration duration of the golf club head present in an absence of the at least one stranded structure. In an embodiment, a surface area of the at least one stranded structure is more than about 10% of the at least one of the crown and the sole. In another embodiment, the sole includes a plurality of inherent vibration frequency regions, each having a known inherent frequency. In yet another embodiment, the vibration dampening material is disposed so as to alter a frequency of at least one of the plurality of the inherent vibration frequency regions from the known inherent frequency to a frequency of less than about 200 Hz.
In another aspect, the technology relates to a golf club head having: a metal club face; a metal crown connected to the club face; a metal sole connected to the club face, wherein the metal club face, the metal crown, and the metal sole at least partially define an interior void; and a polymer plug disposed in a through-hole defined by at least one of the metal crown and the metal sole, wherein a surface area of the polymer plug is greater than or equal to about 5% of the at least one of the metal crown and the metal sole, and the polymer plug has a durometer hardness value within a range of about A20 to about D90. In an embodiment, an external surface of the polymer plug is contoured to substantially match a contour of an exterior surface defined by at least one of the metal crown and the metal sole. In another embodiment, the polymer plug is made from a vibration dampening material having at least one of: an acrylic epoxy, a urethane, a polyurethane, an ionomer, an elastomer, a silicone, and a rubber. In yet another embodiment, the through hole is substantially spiral and is defined by a cantilevered strand of a metal material that is substantially spiral. In still another embodiment, the polymer plug alters at least one of an inherent vibration frequency and an inherent vibration duration of the golf club head present in an absence of the through hole.
In another embodiment of the above aspect, at least one of the metal crown and the metal sole comprises a plurality of inherent vibration frequency regions, each having a known inherent frequency. In an embodiment, the polymer plug is disposed at a predetermined inherent vibration frequency region having a predetermined inherent frequency. In another embodiment, the polymer plug is disposed so as to alter a frequency of the predetermined inherent vibration frequency region from the predetermined inherent frequency to a frequency of less than about 200 Hz. In yet another embodiment, at least one additional polymer plug disposed in at least one additional through hole is defined by at least one of the metal crown and the metal sole.
In another aspect, the technology relates to a method for manufacturing a golf club, the method including: forming a golf club head having a face connected to a sole and a crown so as to define an interior void; removing material from at least one of the crown and the sole so as to form a stranded structure, wherein an unsupported section of the stranded structure is separated from the at least one of the crown and the sole by a through-hole; and filling the through-hole with a vibration dampening material. In an embodiment, the method further includes identifying a portion of at least one of the crown and the sole that emits a sound frequency between 300 Hz to 3 kHz when the golf club head strikes a golf ball, and wherein the removing operation removes a part of the identified portion.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
Non-limiting and non-exhaustive examples are described with reference to the following Figures.
The technologies described herein contemplate a golf club head that utilizes a sole or a crown having a cantilevered strand or a beam strand formed therein. In addition, a gap around the unsupported portion of a cantilevered strand or a beam strand in the sole or the crown may be filled with a polymer that has a stiffness that is much less than that of the (typically metal or rigid composite) crown or sole material. The polymer absorbs the vibrations in the golf club head, thus altering the sound emitted from the club head. By manufacturing the crown or sole, or in some examples both the crown and the sole, to have at least one stranded structure, such as a cantilevered strand or beam strand, the sound properties of the club head may be altered from that of a golf club head without the stranded structure. For instance, a cantilevered strand is a stranded structure supported at one end, whereas a beam strand is a stranded structure supported on at least two ends. In a particular example, portions of the sole or crown that produce an undesirable inherent sound frequency may have that undesirable frequency reduced or otherwise altered by forming a cantilevered strand or beam strand in that portion of the sole or crown. The gap disposed around the stranded structure may then be filled with a polymer so as to reduce the sound frequency associated with that portion of the crown or the sole to a frequency that is difficult to be heard by the human ear. Thus, by controlling the size and location of the strands, the components of the club head can be “tuned” to produce a more desirable sound.
Prior attempts to alter the sound of a club head when it struck a golf ball primarily focused on adding material to the club head to raise the frequency of certain components of the golf club. By way of example, stiffening ribs would be added to the sole of a club head to stiffen the sole, which would result in an increase in the frequency emitted compared to a golf club without the ribs. The present technology takes a contrasting approach to alter the sound emitted from a club head by removing material from the golf club head to add additional flexibility to the components of the club head. The resulting effect is that rather than increasing the frequency of the sound emitted by the component, the frequency of the sound emitted by the component may be reduced or eliminated.
As discussed above, when the golf club head strikes a golf ball, a sound is emitted. The sound may be characterized as having multiple vibration mode frequencies. The emitted sound is due to vibration of the components of the golf club 100 or regions thereof. Each component, such as the sole 106 and the crown 104, may have one vibration frequency across the entire component, or the component may have multiple vibration frequency regions that each vibrate at a different frequency. Example vibration frequency regions are identified in
As described herein, an “inherent vibration” is a vibration that results from a golf ball strike from a standard golf club head, such as golf club head 100, that does not include the stranded structures as described herein. For example, a TITLEIST 915D3 driver, available from Acushnet Company of Fairhaven, Mass., would produce a sound resulting from inherent vibrations. Similarly, the term “inherent vibration frequency region” is a vibration frequency region of a standard golf club that is unmodified, e.g., that is not altered in accordance with the teachings herein. A particular inherent vibration frequency region produces a particular inherent vibration frequency. A “known inherent vibration frequency” is a measured, predetermined, estimated, calculated, or otherwise derived vibration frequency of a golf club head without the stranded structures described herein. Vibration durations may also be similarly described.
The inherent vibration frequencies of the golf club head 100 can be modified by altering the construction of the golf club head 100. For example, an inherent vibration frequency region that contributes to an undesirable sound frequency can be identified and subsequently modified as described herein to reduce or eliminate that undesirable frequency. In an example, the modification includes forming a cantilevered or beam strand in the identified vibration frequency region and filling a gap proximate to the strand with a polymer or other material so as to alter a flexibility and therefore the frequency thereof. As an example, an inherent frequency region that contributes to an undesirable frequency is identified, and a strand is then cut, punched, formed, or otherwise incorporated into the golf club head at a location corresponding to the identified inherent vibration frequency region. In some examples, the duration of the emitted sound frequency may also be reduced. Depending on the particular construction of the cantilevered strand, the emitted sound frequency from the location of the cantilevered strand may be reduced to a level that is difficult to be heard by the human ear, such as a frequency below about 200 Hz.
As shown in
The elongate cantilevered strand 202C may be described as having a length L and a width W, and having a length-to-width ratio. In examples, the length L may be substantially longer than the width W. Depending on the particular application, length-to-width ratios of 2:1 to ratios exceeding 1000:1 may be used. Stranded structures having higher length-to-width ratios will generally exhibit lower acoustic frequencies when the golf club head 200C strikes a golf ball. The elongate cantilevered strand 202C may also be described as having a ratio of width W and a width of the gap 204C, referred to herein as a strand-width-to-gap-width ratio. In examples, the width W of the elongate cantilevered strand 202C may be substantially the same or larger than the width of the gap 204C. Depending on the particular application, strand-width-to-gap-width ratio of 0.1:1 to 100:1 or higher may be used. Yet another potential ratio that may be used to describe the elongate strand 202C is a ratio between the width of the gap 204C and the thickness of the component, such as the sole 206C, defining the gap 204C, referred to herein as a gap-width-to-component-thickness ratio. In some examples, gap-width-to-component-thickness ratios of 0.5:1 to 5:1 may be used. While the above ratios have been discussed with reference to the elongate cantilevered strand 202C, similar ratios may be used to describe any stranded structure discussed herein, including both cantilevered and beam strands.
A beam strand 214D is also defined by the sole 206D. The beam strand 214D is connected to the sole 206D on a first supported end 216D and second supported end 218D. The beam strand 214D has an unsupported center portion 220D.
The cantilevered strands 202D and the beam strand 214D depicted in
While the cantilevered and beam strands of
The acoustic spectrogram in
As shown in the acoustic spectrogram in
As shown in the acoustic spectrogram in
Based on further analysis the results of the production driver and the driver with the spiral cantilevered strand, it was determined that the total sound pressure level produced from the driver with spiral cantilevered strand was reduced by approximately 1.7±0.2 dB. For reference, a 10 dB reduction would be perceived by the human ear as about half as loud. Because both the head speed and ball speed were within the measurement error, as discussed above, approximately equal energy was transferred in each collision. Therefore, the observed reduction in sound pressure is most likely due to the spiral cantilevered strand structure being incorporated into the driver. Additional analysis showed that a club having a spiral cantilevered strand without polymer filling in the gap produced a first mode of vibration around 1 Hz. A club having spiral cantilevered strand with a polymer filler produced a first mode of vibration around 890 Hz. As another example, a club having multiple beam strands produced a first mode around 1.4 kHz.
At operation 604 a stranded structure, such as a cantilevered strand or a beam strand, is formed in one or both of a crown or a sole of a golf club head to be manufactured. The stranded structure may be formed by cutting or punching a casted or forged sole or crown. In other examples, the stranded structure may be formed as part of the casting or forging process by incorporating the stranded structure into a mold. In yet another example, the stranded structure may be added as an insert to the crown or the sole. For example, the crown or the sole may be manufactured with a void for which an insert including the stranded structure would be placed.
At operation 606, the gap or gaps surrounding the stranded structure is filled with a dampening material, such as a flexible polymer as discussed above. In examples where the stranded structure is formed in the crown or the sole as an insert, the gap or gaps may be filled prior to placing the insert into the crown or the sole. For instance, a hole may be cut into or otherwise formed in the crown or sole of the golf club head. The hole is configured to accept an insert having the structures described herein incorporated into the insert. The insert may be attached to the crown or sole via any attachment means, such as welding or adhesives. At operation 608, the golf club head is formed with the modified crown and/or sole. In some examples, the golf club head may be formed prior to the stranded structure being formed into the crown or sole. That is, the stranded structure may be formed by cutting or punching the crown or sole even after the golf club head has been formed. In such embodiments, a traditional golf club head could be modified post-manufacturing to include a stranded structure.
Although specific embodiments and aspects were described herein and specific examples were provided, the scope of the invention is not limited to those specific embodiments and examples. One skilled in the art will recognize other embodiments or improvements that are within the scope and spirit of the present invention. Therefore, the specific structure, acts, or media are disclosed only as illustrative embodiments. The scope of the invention is defined by the following claims and any equivalents therein.
This application is a division of and claims priority to U.S. patent application Ser. No. 14/963,059, now U.S. Pat. No. 10,322,322, filed on Dec. 8, 2015 and titled “Golf Club Having Improved Sound Properties”, which is incorporated in its entirety herein. When a golf club head strikes a golf ball, it emits sound due the vibration of the components of the golf club head. When a driver or fairway metal strikes a golf ball, multiple components vibrate and produce sound at different frequencies. In some instances, the different components of the golf club head, such as the crown and the sole, vibrate with different frequencies that produce a combined sound that is heard by the user. In some golf clubs, multiple regions within each of the components may also vibrate at different frequencies, which all contribute to the combined sound that is heard by the user. The emission of sound is particularly noticeable when drivers or fairway metals strike a golf ball, and may influence a golfer's opinion of the golf club. In fact, some golf clubs available today produce sound characteristics that are displeasing to the user.
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Number | Date | Country | |
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Parent | 14963059 | Dec 2015 | US |
Child | 16436336 | US |