Not Applicable
The present invention relates to a golf club head. More specifically, the present invention relates to a golf club head comprising a novel polymeric material that coats at least a portion of a rear surface of the striking face, which improves the sound of the club head without significantly reducing the golf club head's ball speed or coefficient of restitution.
Golf club heads, and particularly iron-type golf club heads, often include polymeric materials disposed behind the striking face to improve or dampen the sound of the head upon impact with a golf ball. For example, U.S. Pat. No. 5,492,327 discloses an iron with a damping material in a recess, U.S. Pat. No. 6,743,117 discloses a dampening insert behind a strike face insert in an iron, and U.S. Pat. No. 9,168,437 discloses an elastomeric insert attached to the back of the striking face of an iron. Unfortunately, while a polymer fill or insert can improve the sound of the golf club in which it is disposed, this configuration reduces ballspeed off the face, as well as the coefficient of restitution (COR) of the golf club head. This occurs because polymers such as urethane are rigid, with a Poisson's ratio of around 0.5, and when a polymer fills a cavity or space, the polymer prevents the golf club face from flexing. Therefore, there is a need for a golf club head comprising an improved damping material that also preserves, or otherwise optimizes, ballspeed and COR values.
The golf club head comprises a novel material comprising microscopic bubbles (also referred to as hollow beads) made from a strong, lightweight, low-density material such as glass, ceramic, and/or plastic, mixed with a polymeric material, preferably urethane or silicone, at least partially coating a rear surface of a variable thickness striking face. The presence of the microscopic bubbles in the polymeric material prevents the COR of the golf club head from decreasing by more than 0.10, and more preferably by more than 0.05, when compared with a golf club head having all of the same features and characteristics but which lacks a polymeric fill material completely. The fill material is preferably injection molded onto a back surface of the golf club face to fill variable thickness topography and level the rear surface of the golf club face to allow for the attachment of one or more medallions.
One aspect of the present invention is a golf club head comprising a body comprising a striking face, a sole portion, a top portion, a rear portion, and a cavity, and a fill material comprising a first material and a plurality of microscopic bubbles composed of a second material, wherein the second material is different from the first material, wherein the striking face comprises a nonplanar rear surface, wherein the fill material covers at least a portion of the nonplanar rear surface to create a flat plane, and wherein the plurality of microscopic bubbles constitutes 5% to 70% of a volume of the fill material. In some embodiments, the golf club head further comprises a medallion and an adhesive material, and the medallion is affixed to the flat plane with the adhesive material. In a further embodiment, the medallion may comprise or be composed of the fill material.
In yet another embodiment, the golf club head of claim may further comprise a weight, which may be disposed within the cavity. In a further embodiment, the weight may comprise a tungsten alloy. In a further embodiment, the weight may be at least partially enveloped in a urethane material to form a covered weight, which itself may be at least partially or completely enveloped in the fill material. In an alternative embodiment, a combination of the weight and the fill material may completely fill the cavity. In other embodiments, the golf club head may be an iron-type golf club head, each of the plurality of microscopic bubbles may have a diameter of approximately 18-50 microns, and the first material may have a Poisson's ratio of 0.00-0.50. In still other embodiments, the second material (from which the microscopic bubbles are made) may be selected from the group consisting of glass, ceramic, and plastic.
Another aspect of the present invention is a method comprising the steps of providing a golf club head comprising a variable thickness face component with a striking surface and a rear surface, wherein at least a portion of the rear surface is nonplanar, providing a fill material comprising a polymer material and a plurality of microscopic bubbles composed of a low-density material, providing a medallion sized to cover at least a portion of the rear surface, injecting the fill material onto the rear surface to create a flat surface, and affixing the medallion to the flat surface.
In a further embodiment, the method may comprise the step orienting the face component so that the striking surface is parallel with the ground plane, which step may occur prior to the step of injecting the fill material onto the rear surface to create a flat surface. In yet another embodiment, the step of providing a golf club head may comprise the step of casting the variable thickness face component from a metal alloy material. In yet another embodiment, the plurality of microscopic bubbles may constitute 25-30% of the volume of the fill material, and each of the plurality of microscopic bubbles may have a diameter of approximately 18-50 microns.
In another embodiment, the method may further comprise the step of inserting a weight with a density greater than 4 g/cc into a cavity of the golf club head. In a further embodiment, the method may comprise the step of injection-molding the fill material into the cavity and around at least a portion of the weight.
Having briefly described the present invention, the above and further objects, features, and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
The present invention is directed to golf club heads, and particularly iron-type golf club heads, which include a novel fill material comprising a polymeric material and a plurality of microscopic bubbles made of glass, ceramic, and/or plastic, also referred to herein as microscopic, hollow beads. The microscopic bubbles serve two purposes when incorporated with a polymeric material: (1) they lighten the overall fill weight by replacing elastomer with air, thus lowering the material's specific gravity; and (2) they increase the porosity of the fill material, allowing for the formation of micro-holes in the polymeric material. The micro-holes are little air pockets that allow the polymer to flex when the club head impacts a golf ball, thus increasing the COR of the head while at the same time maintaining the sound improvement provided by the polymer itself, such as reduction in dB level and duration. The polymeric material preferably is an elastomer such as polyurethane or silicone having a Poisson's ratio of 0.00-0.50, and more preferably 0.40-0.50, and the microscopic bubbles preferably are measured in D50 micron, which is the median particle size for a measured sample, each microscopic bubble having a diameter of approximately 18-50 microns.
A first embodiment of the golf club head is shown in
In an alternative embodiment, shown in
In yet another embodiment, shown in
In each of the embodiments disclosed herein, the microscopic bubbles in the novel fill material 50 preferably constitute 5% to 70% by volume of the fill material 50, more preferably at least 20% of the volume, and most preferably approximately 25-30% of the fill material's 50 volume.
There are several methods of manufacturing the microscopic bubble fill material 50 and incorporating it into the golf club head 10 according to the present invention. The first method 100, shown in
The second, preferred method 200, shown in
The third method of the present invention is shown in
In order to assess the COR performance of the inventive material, test iron-type golf club heads 10 having unfilled (empty) cavities were created and tested, and compared against golf club heads 10 having the same construction and filled with (1) the novel microscopic bubble fill material 50 comprising polyurethane and glass bubbles and made using one of the second 200 and third methods 300 and (2) polyurethane only. As shown in Tables 1 and 2, the polyurethane-only fill significantly lowers the COR of the golf club head 10. In contrast, when a golf club head cavity is filled with the microscopic bubble fill material 50 (glass) of the present invention, the COR decreases, on average, only by 0.04, thereby retaining the performance benefits of an unfilled golf club head 10. This is particularly evident when the microscopic bubbles or hollow microscopic beads constitute approximately 25% or 30% of the volume of the fill material 50, as shown in Table 1.
In order to assess sound performance, another group of test golf club heads 10 incorporating the 30% by volume novel microscopic bubble fill material 50 comprising polyurethane and glass bubbles, and made using one of the second 200 and third methods 300 were tested and compared with golf club heads 10 having: (1) the same construction and filled with only polyurethane; (2) no polyurethane filler at all; and (3) a small polyurethane snubber insert. As shown in
To assess the effects of the novel fill material on ball speed performance, the performance of a Callaway Golf Apex CF 16 6-iron comprising a small polymeric snubber was compared with the performance of test 6-irons having no fill, test 6-irons with a fill having 30% by volume microscopic bubbles (glass material), and test 6-irons with a fill having 20% by volume microscopic bubbles (glass material). As shown in
In yet another embodiment of the present invention, shown in
The embodiment shown in
In a preferred embodiment, shown in
A method of manufacturing the preferred embodiment is illustrated in
From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.
The present application is a continuation of U.S. patent application Ser. No. 16/996,038, filed on Aug. 18, 2020, and issued on Aug. 17, 2021, as U.S. Pat. No. 11,090,534, which is a continuation of U.S. patent application Ser. No. 16/540,917, filed on Aug. 14, 2019, and issued on Aug. 18, 2020, as U.S. Pat. No. 10,744,379, which is a continuation-in-part of U.S. patent application Ser. No. 16/241,859, filed on Jan. 7, 2019, and issued on May 19, 2020, as U.S. Pat. No. 10,653,930, which is a continuation of U.S. patent application Ser. No. 15/927,917, filed on Mar. 21, 2018, and issued on Jan. 8, 2019, as U.S. Pat. No. 10,173,108, which is a continuation-in-part of U.S. patent application Ser. No. 15/807,851, filed on Nov. 8, 2017, and issued on Aug. 21, 2018, as U.S. Pat. No. 10,052,535, which is a continuation-in-part of U.S. patent application Ser. No. 15/718,285, filed on Sep. 28, 2017, and issued on Aug. 7, 2018, as U.S. Pat. No. 10,039,964, which is a division of U.S. patent application Ser. No. 15/665,004, filed on Jul. 31, 2017, and issued on Nov. 7, 2017, as U.S. Pat. No. 9,808,685, which claims priority to U.S. Provisional Patent Application No. 62/457,086, filed on Feb. 9, 2017, the disclosure of each of which is hereby incorporated by reference in its entirety herein.
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Number | Date | Country | |
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20210370146 A1 | Dec 2021 | US |
Number | Date | Country | |
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62457086 | Feb 2017 | US |
Number | Date | Country | |
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Parent | 15665004 | Jul 2017 | US |
Child | 15718285 | US |
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Parent | 16996038 | Aug 2020 | US |
Child | 17399260 | US | |
Parent | 16540917 | Aug 2019 | US |
Child | 16996038 | US | |
Parent | 15927917 | Mar 2018 | US |
Child | 16241859 | US |
Number | Date | Country | |
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Parent | 16241859 | Jan 2019 | US |
Child | 16540917 | US | |
Parent | 15807851 | Nov 2017 | US |
Child | 15927917 | US | |
Parent | 15718285 | Sep 2017 | US |
Child | 15807851 | US |