Multilayer golf grip and method for manufacturing the same

Abstract

The present invention relates to a golf grip that is attached to the other side of the shaft to which the club head is attached, and is characterized by comprising: a lower inner layer attached to the shaft so as to enclose the shaft with a thickness set to be able to absorb the impact transmitted from the head; an intermediate layer that encloses the upper region including the upper end of the inner layer so as to be able to prevent the shaft from twisting during the process of the user swinging or hitting the ball; and an outer layer that encloses the intermediate layer and the inner layer, having a pattern set to be able to prevent the shaft from slipping from the user's hand during the process of gripping and swinging or hitting. Accordingly, according to the present invention, by forming a multilayer structure to correspond to the various functions of the grip, each layer can stably and effectively perform the grip's original functions of impact absorption, twist prevention, and slip prevention as its main function, and a multilayer golf grip can be provided that can efficiently meet the demands of consumers with diverse power levels.

Description

Technical Field

[0001] The present invention relates to a multi-layer golf grip and a method for manufacturing the same. More specifically, the present invention relates to a multi-layer golf grip having a multi-layer structure including three layers, laminated with synthetic resins having different characteristics including the hardness of the synthetic resin material, and a method for manufacturing the same, in which the structure is improved by molding with a method of injecting materials of different colors into a mold on the upper layer.

Background Art

[0002] A golf club generally includes a club head, a club shaft, and a club grip. The material of the club grip usually includes, for example, a silicone resin. By forming the club grip with such a material, when a golfer, who is a user, holds the club grip, a better grip feeling (grip comfort) can be provided, and better wear resistance and anti-slip effects of the club grip can be obtained.

[0003] When a user hits a golf ball (hereinafter, the ball, the golf ball, the sphere, etc. are also used in the same meaning), the impact angle between the club face and the ball greatly affects the traveling direction of the ball. In order for the ball to travel in the direction intended by the user, it is necessary for the club face to meet the ball at an accurate angle. When the golf club impacts the ball, the force is transmitted to the ball, and the force caused by the impact with the ball is transmitted to the user's hand through the club face, the club shaft, and the club grip.

[0004] Generally, the forces generated by such impacts are understood to have the following effects on the golf club: Specifically, the change in head speed during the swing and the force generated by the clubface impacting the ball cause torsional deformation in the shaft. This causes the clubface to meet the ball at an angle tilted relative to the vertical, resulting in the ball traveling in a direction slightly different from the user's intended direction.

[0005] Based on this understanding, various methods have been proposed to reduce torsional deformation of the club shaft. Furthermore, this phenomenon can occur when the central axis of the club shaft and club grip does not coincide with the point of impact between the ball and the club face.

[0006] Recently, as golf has become more popular, the importance of golf club grips has begun to emerge. Consequently, their importance is being emphasized through various means, including numerous media outlets and online education programs, covering everything from how to hold the club to the function of the grip itself. In particular, the shock absorption, torsional, and slipperiness of the club grip are being highlighted.

[0007] The base of a golf club shaft is the part where the club grip is attached, and it's called the butt. The performance of a golf club grip depends on whether the butt of the grip can absorb the impact energy from a strong impact, minimizing twisting, or preventing the grip from slipping.

[0008] Therefore, leading golf grip manufacturers worldwide invest heavily in research and development to maintain a unique grip feel while suppressing the elasticity of the butt portion where the golf club grip connects.

[0009] Standard club grips employ two methods to prevent twisting in the butt section.

[0010] One is a multi-compound structure, which is a mixed-hardness bonding structure in which the tip of the club grip is joined with low-hardness rubber and the base with high-hardness rubber. The other is a duplex structure, which is a double-layered structure in which the upper layer of the club grip is soft and low-hardness, and the lower layer is hard and high-hardness.

[0011] Here, the multi-compound structure with different hardness levels allows for a high-hardness grip feel at the base, while the duplex structure, although having the disadvantage of higher manufacturing costs due to being composed of two layers, strengthens the overall twist of the club grip while simultaneously providing a softer grip feel.

[0012] On the other hand, alongside twisting, another important function of a club grip is its ability to prevent slippage during the swing. Methods to prevent club grip slippage include effectively selecting materials and adding functional patterns to the surface of the club grip.

[0013] An effective method for selecting materials is to mix a reinforcing material for slip prevention with rubber or synthetic resin. However, adding a large amount of reinforcing material alters the physical properties of the rubber, so only a small amount can be added, and the effect is considered to be minimal. Therefore, recently, a method has been proposed to achieve a more effective grip, slip prevention, and twist prevention by adding a concave functional pattern to the surface of the club grip.

[0014] One of these proposals suggests forming various protrusions on the grip surface and then forming the grip by double injection molding.

[0015] However, it is preferable to have a multi-layered golf grip with three separate layers so that each layer can perform the three functions of a golf club grip: shock absorption, twist prevention, and slip prevention. [Prior art documents] [Patent Documents]

[0016] [Patent Document 1] Korean Registered Patent Publication No. 10-2499567 (Published February 13, 2023) [Patent Document 2] Korean Registered Patent Publication No. 10-2163128 (Published October 8, 2020) [Patent Document 3] Japanese Patent Publication No. 2013-048736 (Published March 14, 2013) [Overview of the project] [Problems that the invention aims to solve]

[0017] The object of the present invention is to provide a multi-layer golf grip and a method for manufacturing the same, which allows each layer to stably and effectively perform its primary function as the grip's main function, such as shock absorption, twist prevention, and slip prevention, by forming a multi-layer structure that corresponds to the diverse functions of the grip.

[0018] Another objective of the present invention is to provide a multi-layer golf grip and a method for manufacturing the same that can efficiently meet the demands of consumers with diverse power levels.

[0019] Another object of the present invention is to provide a multi-layer golf grip and a method for manufacturing the same that can express various colors in appearance without applying paint, cutting materials, or using separate adhesives in the process of realizing various colors.

[0020] Another object of the present invention is to provide a multi-layer golf grip and a method for manufacturing the same that enables stable and continuous operation during the process of forming a multi-layer structure.

[0021] Another object of the present invention is to provide a multi-layer golf grip and a manufacturing method thereof that can vary various properties such as the material and hardness of each layer according to applications and user characteristics, such as male and female, and changes in swing speed, and can expand the scope of application.

Means for Solving the Problems

[0022] An object of the present invention is a golf grip that is coupled to a shaft including a club head, and is provided to be coupled to the shaft so as to wrap the shaft with a thickness set to absorb an impact transmitted from the head, and an inner layer, and during the process of a user swinging or hitting a ball, a middle layer coupled to the outside of the inner layer in an upper region including an upper end portion of the inner layer to prevent the shaft from twisting, and a pattern formed to prevent the shaft from slipping from a hand during the process of a user swinging or hitting, and an outer layer coupled to the outside of the middle layer and the inner layer. The object is achieved by a golf grip characterized by including these layers.

[0023] Further, it is preferable that the inner layer, the middle layer, and the outer layer are sequentially molded by injecting different materials into different molds respectively.

[0024] Further, it is preferable that the middle layer wraps the inner layer by a length set from an upper end portion of the inner layer, and the outer layer is coupled to the outside of the inner layer and the middle layer.

[0025] Further, it is preferable that the protruding heights of the pattern from the outer layer are different from each other, and the height of an upper region, which is a region where a user grips, in the outer layer is higher than that of a lower region.

[0026] Further, it is preferable that the hardness of the middle layer is selected to be different according to the speed of a user's golf club.

[0027] Furthermore, it is preferable that the outer layer includes a first color portion having a first color extending from the upper side to a set length, and a second color portion extending from the first color portion to the lower side having a second color different from the first color.

[0028] Furthermore, it is preferable that the outer circumferential surface of the intermediate layer includes a separation dam protruding at a height close to that of the outer layer, and that the material of the first color portion is injected through a mold from the upper side up to the separation dam, and the material of the second color portion is injected from the separation dam through another mold to form the outer layer.

[0029] Furthermore, it is preferable that the separation levee has a curved shape along the circumferential direction, and that the width of the region where the pressure of the material is concentrated during the injection process of the material of the second collar portion is wider than that of other regions.

[0030] On the other hand, the object of the present invention is a method for manufacturing a golf grip that is attached to a shaft containing a club head, comprising the steps of: forming a cap that forms the upper end of the grip; attaching a rod-shaped mandrel to the central region of the cap along the longitudinal direction of the golf grip to be molded; attaching the mandrel and the cap to a mold A, injecting an inner layer material into the outer circumferential surface of the mandrel and the cap in a set first length to form the inner layer; and attaching the mandrel, the cap, and the inner layer to a mold B, and attaching a setting from the cap to the outer circumferential surface of the inner layer This can also be achieved by a golf grip manufacturing method characterized by including the steps of: injecting intermediate layer material to a second length to form the intermediate layer; joining the mandrel, the cap, the inner layer, and the intermediate layer to a mold C, injecting first color material to the outer surface of the intermediate layer in a region shorter than the second length from the cap to form the first color portion; and joining the mandrel, the cap, the inner layer, the intermediate layer, and the first color portion to a mold D, injecting second color material to the region other than where the inner layer and the first color portion are formed to form the second color portion.

[0031] Furthermore, the hardness of the inner layer, the intermediate layer, and the outer layer including the first and second color portions differs from that of the inner layer, with the intermediate layer having the highest hardness to prevent twisting that occurs when the user strikes the golf ball with the club head, and the inner layer preferably absorbs the impact generated when the club head strikes the golf ball. [Effects of the Invention]

[0032] Therefore, according to the present invention, by forming a multilayer structure to correspond to the diverse functions of the grip, it becomes possible to provide a multilayer golf grip and a method for manufacturing the same in which each layer stably and effectively performs the grip's original functions of shock absorption, twist prevention, and slip prevention as its main function.

[0033] Furthermore, it becomes possible to provide a multi-layer golf grip and a manufacturing method thereof that can efficiently meet the demands of consumers with diverse power levels.

[0034] Furthermore, in the process of realizing various colors, it becomes possible to provide a multi-layer golf grip and a method for manufacturing the same that can express various colors in appearance without applying paint, cutting materials, or using separate adhesives.

[0035] Furthermore, it becomes possible to provide a multi-layer golf grip and a method for manufacturing the same, which allows for stable and continuous operation during the process of forming a multi-layer structure.

[0036] Furthermore, it becomes possible to provide a multi-layer golf grip and its manufacturing method that can expand its range of application by allowing various changes in the material and hardness of each layer to accommodate the characteristics of the application and user, such as whether the user is male or female, and changes in swing speed. [Brief explanation of the drawing]

[0037] [Figure 1]This is a schematic diagram of a golf club including a club grip according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view taken along line AA in Figure 1. [Figure 3] Plan and cross-sectional views illustrating the pattern of the outer layer. [Figure 4] This photograph shows how the outer layers are represented in different colors, as well as the shape of the detached levee. [Figure 5] This figure shows the test results illustrating the effects of the present invention. [Figure 6A] This is a cross-sectional view illustrating the implementation of two types of colored golf grips, one based on the prior art and the other according to the present invention. [Figure 6B] This is a cross-sectional view illustrating the implementation of two types of colored golf grips, one based on the prior art and the other according to the present invention. [Figure 7] This is a schematic diagram illustrating the process for manufacturing a golf grip according to the present invention. [Figure 8A] This is a cross-sectional view illustrating the process of molding a golf grip by injecting material using a mold. [Figure 8B] This is a cross-sectional view illustrating the process of molding a golf grip by injecting material using a mold. [Figure 8C] This is a cross-sectional view illustrating the process of molding a golf grip by injecting material using a mold. [Figure 8D] This is a cross-sectional view illustrating the process of molding a golf grip by injecting material using a mold. [Figure 9A] This is a cross-sectional view illustrating the change in the thickness of the separation levee. [Figure 9B] This is a cross-sectional view illustrating the change in the thickness of the separation levee. [Figure 9C] This is a cross-sectional view illustrating the change in the thickness of the separation levee. [Figure 9D] This is a diagram showing the inside of a golf grip. [Figure 10] This is a schematic flowchart illustrating the manufacturing process of a golf grip according to the present invention. [Modes for carrying out the invention]

[0038] Hereinafter, a golf club grip (100, hereinafter referred to as "golf grip") according to one embodiment of the present invention and its manufacturing method will be described in more detail with reference to Figures 1 to 10.

[0039] Figure 1 is a schematic diagram of a golf club including a club grip according to one embodiment of the present invention; Figure 2 is a cross-sectional view cut along line AA in Figure 1; Figure 3 is a plan view and a cross-sectional view to illustrate the pattern of the outer layer; Figure 4 is a photograph showing how the outer layer is realized in different colors and the shape of the separation dam; Figure 5 is a diagram showing test results to illustrate the effects of the present invention; Figure 6 is a cross-sectional view to illustrate the realization of two types of colored golf grips, one from the prior art and one according to the present invention; Figure 7 is a schematic diagram to illustrate the process of manufacturing a golf grip according to the present invention; Figures 8A to 8D are cross-sectional views to illustrate the process of molding a golf grip by injecting material using a mold; Figures 9A to 9C are cross-sectional views to illustrate the change in the thickness of the separation dam; Figure 9D is an unfolded view of the inner surface of the golf grip; and Figure 10 is a schematic flowchart to illustrate the manufacturing process of a golf grip according to the present invention.

[0040] In the following explanation, for the sake of clarity, as shown in Figure 1, the longitudinal direction of the club shaft 13 will be referred to as the longitudinal direction or vertical direction, the upper end of the shaft 13 (opposite the head 15) will be referred to as the top or upper end, the lower end of the shaft 13 to which the head 15 is attached will be referred to as the bottom or lower end, and the direction along the circumference of the club shaft 13 will be referred to as the circumferential direction or left-right direction.

[0041] A golf grip 100 according to one embodiment of the present invention preferably includes: a lower inner layer 110 attached to the shaft 13, which is the other side of the shaft 13 to which the club head 15 is attached, and which encloses the shaft 13 with a thickness set to primarily absorb the impact transmitted from the head 15; an intermediate layer 120 that encloses the upper region of the inner layer 110 to primarily prevent the shaft 13 from twisting during the process of the user swinging or hitting the ball; and an upper outer layer 130 that encloses the intermediate layer 120 and the inner layer 110, forming a pattern 170 set to primarily prevent the shaft 13 from slipping from the user's hand during the process of gripping and swinging or hitting.

[0042] Furthermore, it is preferable that the inner layer 110, the intermediate layer 120, and the outer layer 130 are extruded sequentially.

[0043] Furthermore, it is preferable that the intermediate layer 120 encloses the inner layer 110 for a length set from the upper end of the inner layer 110 (see "L1" in Figure 2), and that the outer layer 130 is bonded to the outside of the inner layer 110 and the intermediate layer 120.

[0044] In the outer layer 130, it is preferable that the protruding heights of the patterns 170 differ from each other (see "Ha-2", "Hb-2", and "Hc-2" in Figure 3), and that the upper region of the outer layer 130 is taller than the lower region.

[0045] Furthermore, it is preferable that the hardness of the intermediate layer 120 be selected to vary in accordance with the speed of the user's golf club.

[0046] Furthermore, it is preferable that the outer layer 130 includes a first color portion 133 having a first color up to a set height from the top, and a second color portion 135 extending from the first color portion 133 to the bottom and having a second color different from the first color.

[0047] The functions of each layer 110, 120, and 130 of the golf grip 100 are explained above, focusing on their primary roles. However, this does not mean that each layer 110, 120, and 130 does not perform other functions besides their primary ones. For example, the intermediate layer 120 and the outer layer 130 may also have shock-absorbing functions.

[0048] The inner layer 110 encloses the outer surface of the shaft 13 and is bonded to the outer surface of the shaft 13 with a thickness set (the set thickness is formed by the space in the mold).

[0049] The inner surface of the inner layer 110 that connects to the outer surface of the shaft 13 is the inner surface within the space of the mold formed in the extruder to form the inner layer 110. This space in the mold is filled with synthetic resin material supplied to the extruder by heating and pressurizing the material, and the material filling the space forms the inner layer 110.

[0050] As mentioned above, the inner layer 110 primarily functions to absorb the impact caused by increased or accelerated forces and external forces that occur during the swing of the golfer or during the impact when the head 15 strikes the ball.

[0051] For example, the inner layer 110 is responsible for absorbing the impact transmitted to the user's wrist and other parts of their body due to improper force, such as hitting the ground behind them, during the process of hitting the ball. If this impact absorption is insufficient, the user may injure their wrist or experience painful symptoms of golfer's elbow due to the cumulative impact or strong impact.

[0052] While this shock absorption function is primarily handled by the inner layer 110, in the golf grip 100 according to the present invention, it is also possible for the intermediate layer 120 and outer layer 130, which are successively stacked on the outside of the inner layer 110, to absorb shock.

[0053] The inner layer 110 is made of thermoplastic elastomer (TPE), which possesses properties of both rubber and plastic. It is harder than rubber and more flexible and soft than plastic, and is an environmentally friendly material with excellent resilience and shock absorption.

[0054] In addition to the TPE mentioned above, the material forming the inner layer 110 can also contain additives that have the function of absorbing impact.

[0055] Furthermore, the length of the inner layer 110 (see "L" in Figure 2) is preferably in the range of approximately 260 mm to 300 mm from the end of the shaft 13.

[0056] The intermediate layer 120 primarily serves to prevent twisting that occurs during a golfer's swing or impact. The intermediate layer 120 is formed on the outer surface of the inner layer 110, enclosing it for a length set from the upper end of the inner layer 110 or the upper end of the shaft 13 (see "L1" in Figure 2), corresponding to the portion of the golfer's grip that is primarily held during the swing (in the case of swings with drivers, irons, woods, hybrid clubs, etc.).

[0057] The intermediate layer 120 primarily serves to prevent twisting, as mentioned earlier.

[0058] Furthermore, it is preferable that a separation levee 123 is formed protruding from the upper surface of the intermediate layer 120 so as to be close to the height of the outer layer 130.

[0059] In this way, the separation levee 123 is formed, allowing the first color section 133 and the second color section 135, which are subsequent processes, to be molded more stably and effectively. More specific details will be described later.

[0060] Of the three layers 110, 120, and 130, the intermediate layer 120 has the function of preventing twisting because it has a different structure from conventional golf grips that have only one layer. In other words, of the three layers 110, 120, and 130 according to the present invention, the intermediate layer 120 has the characteristic that its hardness can be formed to be different from that of the other layers. That is, the hardness of the intermediate layer 120 can be made different from that of the other layers, namely the inner layer 110 and the outer layer 130. Such a function is only possible with the golf grip 100 having a three-layer, three-stage structure according to the present invention.

[0061] When a golfer swings with the golf grip 100 connected to the shaft 13, the centrifugal force of the head 15 generates two different stresses: a stress in the direction of the shaft 13 and a stress in the circumferential direction of the golf grip 100.

[0062] In this case, the stress is greater on the inside than on the outside, so to maximize the prevention of twisting of the golf grip 100, a material with a higher hardness for the intermediate layer 120 is selected than that for the outer layer 13. At high swing speeds, twisting can be prevented more effectively, and even at high swing speeds, the golf ball can still be impacted in the sweet spot of the head 15 (see Figure 5).

[0063] The material of the intermediate layer 120 preferably contains additional additives to give the TPE high hardness.

[0064] The outer layer 130 primarily serves to prevent the golf grip from slipping from the golfer's hand during the swing or impact, especially when the golfer is holding the club with their hands (usually wearing gloves).

[0065] The outer layer 130 has a pattern 170 that prevents slippage, eliminates water film phenomena, and maintains breathability.

[0066] The material of the outer layer 130 preferably contains additives in TPE, and various colors can be realized by such additives.

[0067] The pattern 170 formed on the outer layer 130 comprises a groove 173 that is recessed downward from the reference line 172 or reference surface, a groove bottom surface 174 which is the bottom of the groove 173, a single-stage projection 175 that protrudes slightly from the reference line 172, and a double-stage projection 176 that protrudes even further than the single-stage projection 175 (see Figures 3(a) to 3(c)).

[0068] In other words, they draw inspiration from an island and then construct another island independently on top of it.

[0069] Pattern 170 allows seawater and wind to freely pass between islands in the sea, while simultaneously enabling moisture from sweat and rain to naturally flow down to lower areas without the formation of a water film. At the same time, it embodies a structure in which the islands appear to float independently, and wind can pass between the islands, ensuring ventilation.

[0070] Furthermore, the recessed and protruding uneven surface provides an easy-to-use non-slip effect, allowing the user to achieve a stable swing even when moisture is present on the golf grip.

[0071] Furthermore, the difference in height is such that it protrudes from the baseline 172, as shown in Figures 3(a) to 3(c) (see "Ha-1", "Hb-1", "Hc-1", and "Ha-2", "Hb-2", and "Hc-2" in Figures 3(a) to 3(c)).

[0072] These height differences are as shown in Figure 2, and the protruding height of pattern 170 may be increased for a certain length from the top of Figure 2 (the "L1" portion in Figure 2), while the remaining portion (referring to the portion of the "L" length in Figure 2 excluding the "L1" portion) may have a lower pattern 170 height. For example, the "L1" portion may be formed in a shape where the protruding heights of the single-stage protrusion 175 and the double-stage protrusion 176 are high, as shown in Figure 3(c), while the remaining portion of the "L" length excluding the "L1" portion may be formed in a shape where the protruding heights of the single-stage protrusion 175 and the double-stage protrusion 176 are intermediate, as shown in Figure 3(b).

[0073] In other words, by making the height of the pattern 170 on the upper part of the golf grip 100 (the "L1" part in Figure 2), which is primarily gripped by the user, higher than other parts, the water film phenomenon can be eliminated, air can pass through the gaps in the pattern 170, and the slipping phenomenon during the swing can be effectively prevented.

[0074] Furthermore, the following points are made regarding the torsional forces acting on the golf club 10 according to the present invention.

[0075] First, the diagrams and formulas related to the twist angle acting on shaft 13 are shown in Table 1 below.

[0076] [Table 1]

[0077] When various forces act on a single axis, the twist angle (Φ) is equal to the sum of the twist angles generated by each force. As shown in Table 1 above, the twist angle (torque) of the entire golf club is equal to the twist angle of the 100 golf grip (Φ in Table 1 above). AB (See "Φ" in Table 1 above) and the twist angle of shaft 13. BC This is the same as the sum of (see "). Expressed as an equation, this is "Φ AC =Φ AB (Grip) + Φ AC (Shaft)

[0078] In other words, if different materials are present on a single shaft, the overall rotational (twist) angle of the torsional moment due to stress will be the sum of the individual twist angles, and the twist angle of the head will be the sum of the twist angles of the grip and shaft.

[0079] For example, if we roughly examine the twist angle of a typical golf club using the above formula, we get the following:

[0080] A typical golf club consists of a shaft and a single-layer golf grip attached to the shaft. In this case, we simply calculate the twist angle of the end of the grip facing the head (see section "A" in Table 1 above). First, assuming that the twist angle of a typical shaft provided by the manufacturer (a long, rod-shaped piece of steel or graphite of a set length to which the head is attached) is "4", and assuming that the twist angle of a golf grip made of synthetic resin including rubber is about "2" greater than the shaft's twist angle of 4, the total twist angle of the golf club will be the sum of "4" and "4+2=6", resulting in "10".

[0081] As shown above, a simple combined twist angle of a golf club may reveal that the head 15 may be significantly open at impact during the swing. However, the twist angle mentioned above is a value simply measured based on the material of the golf club. In reality, the shaft 13 quickly returns to its original state due to its rigidity and restorative force during the swing. Therefore, if a shaft 13 and golf grip 100 of appropriate strength are fitted to match the swing speed and impact power, there is little need to worry.

[0082] On the other hand, golf club grips made of softer, less rigid materials may offer a good grip feel, but they have a larger twist angle and slower recovery force, which can cause changes in the trajectory of the golf ball after impact.

[0083] Therefore, the triple-layered (three-tiered, three-stage) golf grip 100 according to the present invention can be manufactured by changing the strength or hardness of the intermediate layer 120 to accommodate various swing speeds, thereby expanding its range of application, and allowing for the manufacture of customized golf grips 100 as needed.

[0084] Figure 5 shows the position where a golf ball strikes a golf ball when a robotic swing device is used to strike a comparative example (see Comparative Example 1 <Elastomer material golf grip - "Standard"> and Comparative Example 2 <Rubber material golf grip - "Standard2">) and a golf grip according to the present invention (see "Cavier"), when the swing speeds are different.

[0085] As can be seen in the figure, the conventional golf grip 100 does not have a special golf club grip applied in accordance with the swing speed, and it can be seen that the position where the golf ball hits is further away from the sweet spot as the swing speed increases. On the other hand, the golf club grip 100 according to the present invention, by varying the hardness of the intermediate layer 120, can be seen that even when the swing speed increases (as shown in Figure 5, when the swing speed increases from "80 mph" to "100 mph"), the position where the golf ball hits coincides with the sweet spot, or the degree of deviation is very small.

[0086] To illustrate with an example of the present invention, in the case of a swing speed of 80 mph (typically when the shaft strength is "R"), the outer layer material hardness was set to "48", the intermediate layer 120 material hardness to "60", and the inner layer 110 material hardness to "65".

[0087] On the other hand, for a swing speed of 100 mph (typically with a shaft strength of "S"), the outer layer material hardness was set to "48", the middle layer material hardness to "70", and the inner layer material hardness to "65".

[0088] In other words, according to the present invention, the hardness of each layer 110, 120, and 130 can be varied as needed, which has the advantage of being able to appropriately accommodate differences between men's and women's golf clubs, as well as changes in swing speed.

[0089] The cap 150 is a cap-shaped cap with a through hole formed in the center at the upper end of the golf grip 100, as shown in Figure 2, and has a slightly stronger hardness (for example, around "75") compared to the other parts that connect with the inner layer 110, the intermediate layer 120, and the outer layer 130.

[0090] Furthermore, as shown in Figure 4, unlike the prior art, the golf grip 100 according to the present invention can be formed by extruding or pressurizing an outer layer 130 made of a material having two different colors, a first color portion 133 and a second color portion 135, and molded on the outside of the intermediate layer 120 and the inner layer 110.

[0091] Unlike conventional methods that involve cutting a golf grip to create two different colors (see Figure 6(a)), this molding method, as shown in Figure 6, does not require any additional cutting or adhesive. Instead, the first color portion 133 and the second color portion 135 are molded by high-pressure extrusion (see Figure 6(b)) so that they are stably bonded together. Therefore, the golf grip 100 product according to the present invention has the advantage of increased reliability.

[0092] Figure 7 is a schematic diagram illustrating the process for manufacturing the golf grip 100 according to the present invention.

[0093] In the golf grip 100 according to the present invention, the process of forming the golf grip 100 involves the material part (not shown in reference numerals) moving in and out of the mold part (not shown in reference numerals), and performing primary molding, secondary molding, tertiary molding, and quaternary molding by rotating 90 degrees in accordance with each process, so that the primary mold, secondary mold, tertiary mold, and quaternary mold of the mold part are positioned at positions corresponding to each molding process.

[0094] As a result, each layer, consisting of the inner layer 110, the intermediate layer 120, and the outer layer 130 having the first color portion 133 and the second color portion 135, can be formed by material supplied under pressure to each mold during the primary molding, secondary molding, tertiary molding, and quaternary molding processes.

[0095] In each molding process, liquid material is supplied to the inside of the mold, the supplied material is cooled, and then the next batch of liquid material is supplied onto the cooled material in the mold for the next molding process, and this process is repeated.

[0096] In other words, the inner layer 110 is formed in the primary molding stage, the intermediate layer 120 is formed in the secondary molding stage, the first color portion 133 is formed in the tertiary molding stage, and the second color portion 135 is formed in the quaternary molding stage.

[0097] Multiple golf grips (four in Figure 7) may be molded during each molding process. Since the entry and exit of the material into and out of the mold and the rotation of the material are performed automatically, continuous automated operation is possible, which increases work efficiency.

[0098] The manufacturing process of a golf grip 100 having such a configuration will be explained in detail below with reference to Figures 8A to 10.

[0099] First, as shown in Figures 8A and 10, the cap 150 is molded (the cap is molded by a mold not shown, S510), and then a long rod-shaped mandrel 20 is attached to the central region of the cap 150 (S520). Figure 8A shows the state in which the mandrel and cap are attached to mold A with the mandrel attached to the cap.

[0100] The mandrel 20 and cap 150 are positioned inside the upper and lower molds of mold A (see "Upper Mold A" and "Lower Mold A" in Figure 8A; the same applies to Figures 8B to 8D below), and once the mandrel 20 and cap 150 are positioned inside the set mold A, the upper and lower molds of mold A move to the material injection position.

[0101] At this position, the inner layer material is injected into the internal space of mold A through the material injection port (not shown) of mold A, filling the outer surface of the mandrel 20 and one side of the cap 150 with the inner layer material, and forming the inner layer 110 (S530).

[0102] After the material is injected and the upper and lower molds of mold A are separated after cooling, the cap 150, mandrel 20, and inner layer 110 are separated from mold A and move to the outside of mold A (the "material part" is separated from the "mold part" in Figure 7). Typically, the temperature of the material injected into each mold is about 180°C to 200°C, and the temperature after cooling is about 30°C to 40°C.

[0103] The material temperature and cooling temperature of the intermediate layer 120, described below, and the outer layer 130 including the first color portion 133 and the second color portion 135 are approximately the same.

[0104] Here, as shown in Figure 7, the "mold section" is the region where "mold A," "mold B," "mold C," and "mold D" are located, and the "material section" may be divided into the following regions: a region where the inner layer is formed and the mandrel is supported while the cap and mandrel are joined; a region where the mandrel is supported while the inner layer and intermediate layer are formed on the cap and mandrel; a region where the mandrel is supported while the inner layer, intermediate layer, and first color section are formed on the cap and mandrel; and a region where the mandrel is supported while the inner layer, intermediate layer, first color section, and second color section are joined on the cap and mandrel.

[0105] Next, the configuration formed by the cap 150, mandrel 20, and inner layer 110, which has been separated from and moved from mold A, rotates to the position of mold B, and then positions itself inside mold B (at this position, the upper and lower molds of mold B are separated). Once placed in the fixed position of mold B, the upper and lower molds of mold B are joined together.

[0106] As shown in Figure 8B, a material for forming the intermediate layer 120 is injected into the space formed by the joining of the upper and lower molds of mold B. After cooling, the intermediate layer 120 is formed on the inner layer 110 for a set length from the cap 150 (see "L1" in Figures 8A to 8D) (S540).

[0107] Next, the cap 150 and mandrel 20, on which the inner layer 110 and intermediate layer 120 are formed, are separated from the mold B. The specific separation process is as described above.

[0108] In this case, it is preferable that a separation embankment 123 is formed at a position separated by a set distance from the lower end of the intermediate layer 120, and at a height close to the outside of the outer layer 130, protruding from another plate surface of another intermediate layer 120.

[0109] Next, the cap 150, mandrel 20, and the configuration with the inner layer 110 and intermediate layer 120, which have been separated from and moved from mold B, are rotated to the position of mold C, and then positioned inside mold C (at this position, the upper and lower molds of mold C are separated). Once placed in the fixed position of mold C, the upper and lower molds of mold C are joined together.

[0110] As shown in Figure 8C, the material that will form the first color section 133 is injected into the space formed by the joining of the upper and lower molds of mold C, and after cooling, the first color section 133 is formed in the space from the cap 150 to the separation dam 123 (S550).

[0111] Next, the cap 150 and mandrel 20, on which the inner layer 110, intermediate layer 120, and first color portion 133 are formed, are separated from the mold C. The specific process of separation is as described above.

[0112] Next, the cap 150, mandrel 20, and the configuration formed by the inner layer 110, intermediate layer 120, and first color portion 133, which have been separated and moved from mold C, are rotated to the position of mold D, then positioned inside mold D (at this position, the upper and lower molds of mold D are separated), and when placed in the fixed position of mold D, the upper and lower molds of mold D are joined together.

[0113] As shown in Figure 8D, the material for forming the second color portion 135 is injected into the space formed by the joining of the upper and lower molds of mold D, and after cooling, the second color portion 135 is formed in the space from the separation dam 123 to the lower side of the golf grip 100 (S560).

[0114] Next, the cap 150 and mandrel 20, on which the inner layer 110, intermediate layer 120, first color portion 133, and second color portion 135 are formed, are separated from the mold D. The specific separation process is as described above.

[0115] The golf grip 100, which includes the cap 150, inner layer 110, intermediate layer 120, first color section 133, and second color section 135 bonded to the mandrel 20 after undergoing this process, is separated from the mandrel 20 and undergoes final inspection followed by packaging and other processes.

[0116] Here, referring to Figures 8C to 9C, the function of the separation levee 123 during the process of forming the first color section 133 and the second color section 135 can be explained as follows.

[0117] As shown in Figure 9A, the separation levee 123 is formed as a projection on the lower part of the intermediate layer 120. If the longitudinal direction of the golf grip 100 is taken as the Y-axis and the circumferential direction of the golf grip as the X-axis, then the shape is a regular arrangement of generally concave and bulging parabolic shapes, as shown in Figure 9A.

[0118] Here, as shown in Figures 9B and 8C, when the material for the first collar section 133 is injected into the internal space of the mold C, the pressure pressing down on the material pressurizes the separation dam 123. This pressurization causes the surface of the mold C that supports the left side of the separation dam 123 to resist the pressure from the material (see "F mold" in Figure 9B), and the resistance force of the mold C becomes more stable because the mold C is made of metal.

[0119] On the other hand, as shown in Figures 9C and 8D, when the material for the second color section 135 is injected into the internal space of the mold D, the pressure that pressurizes the material pressurizes the separation dam 123. This pressurization causes the separation dam 123 of the mold D and the first color section 133 to the right of the separation dam 123 to exert a force that resists the pressure applied to the material (see "F" in Figure 9C). Since the temperature of the second color section 135 is approximately 180°C to 200°C, the high temperature affects the separation dam 123 and the first color section 133 which is close to the separation dam 123, and the ability to prevent the second color section 135 from flowing into the separation dam 123 or the first color section 133 is reduced compared to Figure 9B.

[0120] Furthermore, as shown in Figure 9A, in this phenomenon, as force is transmitted from the second color section 135 on the left to the separation levee 123 or the first color section 133 on the right, the pressing force concentrates in the concave region. Therefore, it is preferable that the concave portion where the force concentrates (indicated as "W2" in Figure 9A) is wider than the convex portion (indicated as "W1" in Figure 9A). In other words, as shown in Figure 9A, it is preferable that "W2" is wider than "W1".

[0121] This structure allows the outer layer 130 to be made of two different colors, resulting in a beautiful appearance.

[0122] Furthermore, by configuring the lower, bulging portion of the parabolic concave or bulging section as the area where the user's thumb rests when gripping the golf grip 100, it becomes possible to manufacture a golf grip 100 with a pattern 170 shape that allows the user to maintain a more stable grip when hitting a golf ball with the golf grip 100, preventing the hand from slipping.

[0123] The through-holes 180 are holes that allow material to pass through to other layers, so that even when the plastic material is bonded to each other inside each mold, the bonding between layers is more effective. It is preferable that such through-holes 180 are formed spaced apart from each other according to the set positions of each layer.

[0124] Such through-holes 180 include inner layer through-holes 183 formed in the inner layer 110 and intermediate layer through-holes 185 formed through the intermediate layer 120 and the inner layer 110. Although not shown in the figures, through-holes formed only in the intermediate layer 120 may also exist.

[0125] The intermediate layer 120 material flows into the inner layer through-hole 183, making the bond between the inner layer 110 and the intermediate layer 120 stronger, and the outer layer 130 material flows into the intermediate layer through-hole 185, making the bond between the intermediate layer 120 and the outer layer 130 or the inner layer 110 stronger.

[0126] Figure 9D is an unfolded view of the inner surface of a golf grip to show an example in which such inner through-holes 183 and intermediate layer through-holes 185 are formed up to the inner surface of the golf grip. [Industrial applicability]

[0127] By forming a multi-layer structure to accommodate the diverse functions of the grip, it is possible to provide a multi-layer golf grip and a method for manufacturing the same, in which each layer stably and effectively performs the grip's original functions of shock absorption, twist prevention, and slip prevention as its primary function.

[0128] Furthermore, it is possible to provide a multi-layer golf grip and a method for manufacturing the same that can efficiently meet the demands of consumers with diverse power levels.

[0129] Furthermore, in the process of realizing various colors, it is possible to provide a multi-layer golf grip and a method for manufacturing the same that can express various colors in appearance without applying paint, cutting materials, or using separate adhesives.

[0130] Furthermore, it is possible to provide a multi-layer golf grip and a method for manufacturing the same, which allows for stable and continuous operation during the process of forming a multi-layer structure.

[0131] Furthermore, it is possible to provide a multi-layer golf grip and a method for manufacturing the same, which can expand its range of application by allowing various changes in the material and hardness of each layer to accommodate the characteristics of the application and user, such as whether the user is male or female, and changes in swing speed. [Explanation of symbols]

[0132] 100: Golf Grips 110: Inner layer 120: Middle class 123: Separation embankment 130: Outer layer 133: First Color Section 135: Second color section 150: Cap 170: Pattern 172: Reference plane 173: Groove 174:Groove bottom 175: 1 step protrusion 176: 2-stage protrusion 180: Through Hole 183: Inner layer through hole 185: Intermediate layer penetration hole 10: Golf Club 13: Shaft 15: Head 20: Mandrel

Claims

1. A golf grip that is attached to a shaft containing a club head, An inner layer is provided that can be coupled to the shaft so as to enclose the shaft with a thickness set to be able to absorb the impact transmitted from the head, An intermediate layer is bonded to the outer surface of the inner layer in an upper region including the upper end of the inner layer, so as to prevent the shaft from twisting during the user's swing or when hitting the ball, It includes an outer layer bonded to the outside of the intermediate layer and the inner layer, which has a pattern set to prevent the shaft from slipping from the user's hand during the swing or strike process. A golf grip characterized by the following features.

2. The inner layer, the intermediate layer, and the outer layer are molded sequentially by injecting different materials into each of them using different molds. The golf grip according to claim 1.

3. The intermediate layer encloses the inner layer for a length set from the upper end of the inner layer, and the outer layer is bonded to the outside of the inner layer and the intermediate layer. The golf grip according to claim 1 or 2.

4. The heights of the patterns protruding from the outer layer differ from one another, and the upper region of the outer layer, which is the area held by the user, is higher than the lower region. The golf club according to claim 1 or 2.

5. The hardness of the intermediate layer is selected to vary in accordance with the speed of the user's golf club. The golf club described in claim 3.

6. The outer layer includes a first color portion having a first color extending from the upper side to a set length, and a second color portion extending from the first color portion downwards and having a second color different from the first color. The golf club described in claim 3.

7. The outer periphery of the intermediate layer includes a separation embankment that protrudes at a height close to that of the outer layer. The material for the first color section is injected through the mold from the upper side up to the separation levee. The material for the second color section is injected from the aforementioned separation levee through another mold to form the outer layer. The golf club according to claim 6.

8. The aforementioned separation embankment has a shape that is bent along the circumferential direction, During the process of injecting the material into the second color section, the area where the pressure of the material is concentrated is formed to be wider than other areas. The golf club according to claim 7.

9. A method for manufacturing a golf grip that is attached to a shaft containing a club head, The steps include forming a cap that forms the upper end of the grip, The steps include: attaching a rod-shaped mandrel to the central region of the cap, along the longitudinal direction of the golf grip to be molded; The steps include: joining the mandrel and the cap to mold A, injecting the inner layer material into the outer surface of the mandrel and the cap in a predetermined first length, and forming the inner layer; The steps include: joining the mandrel, the cap, and the inner layer to mold B, injecting the intermediate layer material onto the outer surface of the inner layer at a second length set from the cap, and forming the intermediate layer; The steps include: bonding the mandrel, the cap, the inner layer, and the intermediate layer to a mold C, injecting the material for the first color portion into the outer surface of the intermediate layer in a region shorter than the second length from the cap, thereby forming the first color portion; The process includes the steps of: joining the mandrel, the cap, the inner layer, the intermediate layer, and the first color portion to a mold D; injecting the material for the second color portion into the area other than where the inner layer and the first color portion are formed; and forming the second color portion. A method for manufacturing golf grips characterized by the following features.

10. The hardness of the inner layer, the intermediate layer, and the outer layer including the first color portion and the second color portion differs from that of the other. By making the hardness of the aforementioned intermediate layer the highest, it is possible to prevent twisting that occurs during the process of the user hitting the golf ball with the club head. The aforementioned inner layer absorbs the impact generated when the club head strikes the golf ball. The method for manufacturing a golf grip according to claim 9.

11. A separation embankment is formed on the outer circumferential surface of the intermediate layer, protruding at a height close to that of the outer layer. The material for the first color section is injected through the mold from the upper side up to the separation levee. The material for the second color section is injected from the aforementioned separation levee through another mold to form the outer layer. The method for manufacturing a golf club according to claim 9.

12. The aforementioned separation embankment has a shape that is bent along the circumferential direction, During the process of injecting the material into the second color section, the area where the pressure of the material is concentrated is formed to be wider than other areas. The method for manufacturing a golf club according to claim 11.

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