Paddle tennis racket having core rib sheet and manufacturing method thereof

Abstract

The present invention illustrates a paddle tennis racket (1) having a core rib sheet (132), which includes a ball hitting portion (10) and a handle portion (20). The ball hitting portion (10) includes a racket frame (11), a first surface layer (12), a second surface layer (14), and an internal structure (13). The racket frame (11) has an inner wall (111) and an accommodating space. The internal structure (13) is disposed in the accommodating space and includes an upper core material layer (131), a lower core material layer, (133) and a core rib sheet (132) piled between the upper core material layer (131) and the lower core material layer (133). The first surface layer (12) is laid on the top surface of the upper core material layer (131). The second surface layer (14) is laid on the bottom surface of the lower core material layer (133). The aforementioned racket frame (11), first surface layer (12), second surface layer (14) and core rib sheet (132) are all made of carbon fiber reinforced composite material, and the first surface layer (12), the second surface layer (14) and the core rib sheet (132) are all integrally connected with the racket frame (11). By the structural configuration of the aforementioned paddle tennis racket (1), the overall rigidity of the paddle tennis racket (1) is raised.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The present invention relates to a method for manufacturing a paddle tennis racket and specifically speaking, to a manufacturing method of a paddle tennis racket having a core rib sheet, which has a relatively better rigidity in overall structure.2. Description of the Related Art

[0002] Paddle tennis is a sport played with a racket for hitting a ball and similar to tennis. Paddle tennis can be played as singles or doubles, which is smaller in both activity quantity and exercise quantity than tennis and thus suitable for people of all ages, gradually becoming popular and liked by the general masses in recent years.

[0003] The traditional paddle tennis racket is provided therein with a uniform core which is made of a single core material. Limited by the material and structure of the core, the rigidity of the traditional paddle tennis racket is relatively lower. Therefore, when the player hits the ball, the ball bounces off the racket with relatively smaller force, that may weaken the performance of the player attacking and counterattacking during the game. CN216653316 U discloses a racket tool with a frame body, a handle. The frame body comprises a frame wall and a grab handle which are connected with each other, and the frame wall encloses an accommodating space; the three-dimensional net rack is arranged in the accommodating space, one circumferential side of the three-dimensional net rack is fixedly connected to the frame wall, and the three-dimensional net rack comprises a plurality of channels penetrating through the two sides of the three-dimensional net rack in the thickness direction. The two face patting parts are arranged on the two opposite sides of the three-dimensional net rack and fixedly connected to the frame wall, each face patting part comprises a plurality of through holes, and the through holes correspond to and are communicated with the channels.SUMMARY OF THE INVENTION

[0004] It is one of the objectives of the present disclosure to provide a paddle tennis racket with a brand-new structural configuration, the overall structure of which has a relatively better rigidity.

[0005] To attain the above objective, this application provides the following manufacturing method: A manufacturing method of a paddle tennis racket having a core rib sheet includes a ball hitting portion, and a handle portion connected with the ball hitting portion. The aforementioned ball hitting portion includes a racket frame, a first surface layer, a second surface layer, and an internal structure. The racket frame has an inner wall, and an accommodating space formed in an encircled manner by the inner wall. The internal structure is disposed in the accommodating space, and includes an upper core material layer, a lower core material layer, and a core rib sheet piled between the upper core material layer and the lower core material layer. The first surface layer is laid on the top surface of the upper core material layer. The second surface layer is laid on the bottom surface of the lower core material layer. The aforementioned racket frame, first surface layer, second surface layer and core rib sheet are all made of carbon fiber reinforced composite material, and the first surface layer, the second surface layer and the core rib sheet are all integrally connected with the racket frame. The manufacturing method includes the steps of: providing a plurality of windable sheet materials coated with resin, and an expandable material, the windable sheet materials being made of carbon cloth; winding the windable sheet materials coated with resin on the exterior of the aforementioned expandable material to form a tube-shaped structure, the aforementioned tube-shaped structure having a first end portion and a second end portion opposite to the first end portion; bending the aforementioned tube-shaped structure in a way that the aforementioned tube-shaped structure is formed with a frame and a column connected with the frame, an accommodating space is formed in an encircled manner by the inner wall of the aforementioned frame, and the first end portion and the second end portion are abutted upon each other linearly to be formed into the aforementioned column; laying a lower composite sheet material, a lower core material layer, a first middle composite sheet material, a second middle composite sheet material, an upper core material layer and an upper composite sheet material in the aforementioned accommodating space in bottom-up order, bending the outer periphery of the first middle composite sheet material downwardly to make the outer periphery of the first middle composite sheet material attached between the inner wall of the frame and the lower core material layer, and bending the outer periphery of the second middle composite sheet material upwardly to make the outer periphery of the second middle composite sheet material attached between the inner wall of the frame and the upper core material layer, wherein the lower composite sheet material, the first middle composite sheet material, the second middle composite sheet material and the upper composite sheet material are all made of carbon cloth; the after-bending tube-shaped structure and the after-laying lower composite sheet material, lower core material layer, first middle composite sheet material, second middle composite sheet material, upper core material layer and upper composite sheet material are collectively defined as a preformed member; pressurizing and heating the aforementioned preformed member and expanding the aforementioned expandable material to make the column heat cured and then formed into the handle portion of the paddle tennis racket, make the frame heat cured and then formed into the racket frame of the paddle tennis racket, make the upper composite sheet material heat cured and integrally connected with the racket frame and then formed into the first surface layer of the paddle tennis racket, make the lower composite sheet material heat cured and integrally connected with the racket frame and then formed into the second surface layer, and make the first middle composite sheet material and the second middle composite sheet material heat cured, integrally connected with each other and both integrally connected with the racket frame and then collectively formed into the core rib sheet of the paddle tennis racket, so that the after-forming upper core material layer, lower core material layer and core rib sheet are collectively defined as the internal structure, the after-forming racket frame, first surface layer, second surface layer and internal structure are collectively defined as the ball hitting portion, and the ball hitting portion and the handle portion are collectively defined as the aforementioned paddle tennis racket.

[0006] By the structural configuration of the aforementioned paddle tennis racket, the first surface layer, the second surface layer and the core rib sheet, which are made of carbon fiber reinforced composite material and have high strength, are all parallel to each other to be connected with the inner wall of the racket frame, so the first surface layer, the second surface layer and the core rib sheet structurally present a parallel connected condition. On the transverse cross section, the integrally connected core rib sheet and racket frame form a structure similar to the English letter "I", that makes the overall rigidity of the paddle tennis racket relatively better. Therefore, the force of the hit ball transmitted to the interior of the paddle tennis racket can be borne relatively better and bounced back to the ball, causing the bouncing ball relatively stronger power, that can be conducive to the performance of the player attacking and counterattacking during the game.

[0007] The upper core material layer and the lower core material layer may be equal in thickness.

[0008] The upper core material layer and the lower core material layer may be made of a same material. In some situations, the upper core material layer and the lower core material layer may be made of different materials.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The detailed structure, features and manufacturing steps related to the paddle tennis racket will be described in the following example. However, it should be understandable that the example and the accompanying drawings to be described herein below are given by way of illustration only, not limitative of the claims of the present invention, and wherein: FIG. 1 is a perspective view of a paddle tennis racket manufactured by the method of the invention; FIG. 2 is a top view of FIG. 1; FIG. 3 is a sectional view taken along the line 3-3 in FIG. 2; FIG. 4 is a sectional view taken along the line 4-4 in FIG. 2; FIG. 5 is a flow chart of the manufacturing method of the paddle tennis racket of an embodiment of the invention; and FIG. 6A to FIG. 6J are schematic views corresponding to the steps in the flow chart of the manufacturing method. DETAILED DESCRIPTION OF THE INVENTION

[0010] The technical content and features of the present invention will be detailedly described by the instanced example and the accompanying drawings given herein below. The directional terms mentioned in the content of this specification, such as 'upper', 'lower', 'in', 'out', 'top' and 'bottom' are all just for illustrative description on the basis of normal usage direction, not intended to limit the claimed scope.

[0011] For the detailed description of the technical features of the present invention, the following example is instanced and described in coordination with the accompanying drawings herein below.

[0012] As shown in FIG. 1 to FIG. 4, a paddle tennis racket 1 is provided which includes a ball hitting portion 10, and a handle portion 20 connected with the ball hitting portion 10. The ball hitting portion 10 is the portion of the paddle tennis racket 1 for hitting the ball. In usual situations, the thickness of the ball hitting portion 10 is ranged from 22 millimeters to 38 millimeters (mm), so as to meet the standard of the paddle tennis racket 1. The ball hitting portion 10 structurally includes a racket frame 11, a first surface layer 12, an internal structure 13, and a second surface layer 14. The racket frame 11 is formed from carbon fiber reinforced composite material by pressurizing and heating and then solidified. The inside of the racket frame 11 in this embodiment is hollow in shape. The racket frame 11 has an inner wall 111, and an approximately diamond-shaped accommodating space is formed in an encircled manner by the inner wall 111. The internal structure 13 is disposed in the aforementioned accommodating space. The first surface layer 12 and the second surface layer 14 are the parts for directly contacting the ball. The first surface layer 12 and the second surface layer 14 are also made of carbon fiber reinforced composite material. The first surface layer 12 is integrally connected with the upper rim of the racket frame 11. The second surface layer 14 is integrally connected with the lower rim of the racket frame 11.

[0013] The internal structure 13 is disposed between the first surface layer 12 and the second surface layer 14. The internal structure 13 includes an upper core material layer 131, a lower core material layer 133, and a core rib sheet 132 piled between the upper core material layer 131 and the lower core material layer 133. The aforementioned first surface layer 12 is laid on the top surface of the upper core material layer 131. The upper core material layer 131 is a foam layer structure, and made of EVA (ethylene-vinyl acetate) by foaming. The Shore hardness of EVA is Shore A 10-25. EVA has great rigidity, and is conducive to hitting feeling. The core rib sheet 132 is arranged for providing supporting effect. A plurality of sheets of carbon cloth are piled and solidified to become the core rib sheet 132. The outer periphery of the core rib sheet 132 is integrally connected with the racket frame 11. The second surface layer 14 is laid on the bottom surface of the lower core material layer 133. The lower core material layer 133 is also a foam layer structure, and also made of EVA by foaming. The thickness of the lower core material layer 133 is equal to the thickness of the upper core material layer 131. Because the racket frame 11, the first surface layer 12, the second surface layer 14 and the core rib sheet 132 are all made of carbon fiber reinforced composite material, in the process that a mold and an expandable material, which will be detailedly described in the paragraphs herein below, are used for heating and pressurizing the carbon fiber reinforced composite material, the carbon fiber reinforced composite material will be softened and undergo a crosslinking reaction, so as to be formed into the appearance of each aforementioned component.

[0014] Besides, as shown in FIG. 1 and FIG. 4, the ball hitting portion 10 is further provided with a plurality of through holes 15. Each through hole 15 penetrates through the first surface layer 12, the internal structure 13 and the second surface layer 14, enabling air flow to pass through the ball hitting portion 10 smoothly, thereby lowering wind resistance.

[0015] The handle portion 20 is arranged for the user to hold. The handle portion 20 is integrally connected with the racket frame 11. Besides, the handle portion 20 is covered with a grip strap 21 for anti-slip and anti-vibration.

[0016] By the structural configuration of the aforementioned paddle tennis racket 1, the first surface layer 12, the second surface layer 14 and the core rib sheet 132, which are made of carbon fiber reinforced composite material and have high strength, are all parallel to each other to be connected with the inner wall 111 of the racket frame 11, so the first surface layer 12, the second surface layer 14 and the core rib sheet 132 structurally present a parallel connected condition. On the transverse cross section, the integrally connected core rib sheet 132 and racket frame 11 form a structure similar to the English letter "I", that makes the overall rigidity of the paddle tennis racket 1 relatively better. Therefore, the force of the hit ball transmitted to the interior of the paddle tennis racket 1 can be borne relatively better and bounced back to the ball, causing the bouncing ball relatively stronger power, that can be conducive to the performance of the player attacking and counterattacking during the game.

[0017] According to the invention a manufacturing method is provided for manufacturing the paddle tennis racket 1'. Referring to FIG. 5 to FIG. 6J, the aforementioned manufacturing method includes the following steps: The step S1: the start step: provide a plurality of windable sheet materials S coated with resin, and an expandable material F, as shown in FIG. 6A. The windable sheet materials S are essentially a plurality of layers of carbon cloth. The expandable material F in this embodiment is a gas bag. The gas bag can be inflated to expand. According to different manufacturing processes, the gas bag may be filled with foam material.

[0018] The step S2: wind the windable sheet materials S coated with resin on the exterior of the expandable material F to form a tube-shaped structure T, as shown in FIG. 6B. The aforementioned tube-shaped structure T has a first end portion E1 and a second end portion E2 opposite to the first end portion E1. At this time, the expandable material F is not inflated to expand yet.

[0019] The step S3: place the aforementioned tube-shaped structure T in a cavity C of a mold M, and bend the aforementioned tube-shaped structure T to make the tube-shaped structure T formed with a frame 30 and a column 40 connected with each other, as shown in FIG. 6C, wherein an accommodating space R is formed in an encircled manner by the inner wall of the frame 30, and the first end portion E1 and the second end portion E2 are abutted upon each other linearly to be formed into the column 40.

[0020] For the convenience of illustrating the following steps, FIG. 6D to FIG. 6H are drawn as sectional views from the same perspective with that along the line L-L in FIG. 6C.

[0021] The step S4: in the cavity C and in the accommodating space R, lay a layer of lower composite sheet material 16 on the inner wall of the cavity C (as shown in FIG. 6D), lay a lower core material layer 133 on the lower composite sheet material 16 (as shown in FIG. 6E), lay a first middle composite sheet material 17 and a second middle composite sheet material 18 on the lower core material layer 133, bend the outer periphery of the first middle composite sheet material 17 downwardly to make the outer periphery of the first middle composite sheet material 17 attached between the inner wall of the frame 30 and the lower core material layer 133, and bend the outer periphery of the second middle composite sheet material 18 upwardly (as shown in FIG. 6F). After that, lay an upper core material layer 131 on the second middle composite sheet material 18 to make the outer periphery of the second middle composite sheet material 18 attached between the inner wall of the frame 30 and the upper core material layer 131, as shown in FIG. 6G. At last, lay an upper composite sheet material 19 on the upper core material layer 131, as shown in FIG. 6H. In some situations, a reinforcing rib 50 (shown in FIG. 6J) may be further placed. The lower composite sheet material 16, the first middle composite sheet material 17, the second middle composite sheet material 18 and the upper composite sheet material 19 are all made of carbon cloth. The upper core material layer 131 and the lower core material layer 133 may be made of EVA by foaming, and the upper core material layer 131 and the lower core material layer 133 are equal in thickness. The after-bending tube-shaped structure T and the after-laying lower composite sheet material 16, lower core material layer 133, first middle composite sheet material 17, second middle composite sheet material 18, upper core material layer 131 and upper composite sheet material 19 are collectively defined as a preformed member.

[0022] The step S5: pressurize and heat the aforementioned preformed member through the aforementioned mold M, and inflate the expandable material F to expand the aforementioned expandable material F, so that the column 40 is heat cured and then formed into the handle portion 20, the frame 30 is heat cured and then formed into the racket frame 11, the upper composite sheet material 19 is heat cured and integrally connected with the racket frame 11 and then formed into the first surface layer 12, the lower composite sheet material 16 is heat cured and integrally connected with the racket frame 11 and then formed into the second surface layer 14, the first middle composite sheet material 17 and the second middle composite sheet material 18 are heat cured, integrally connected with each other and both integrally connected with the racket frame 11 and then collectively formed into the core rib sheet 132 (as shown in FIG. 6I), and thus the after-forming upper core material layer 131, lower core material layer 133 and core rib sheet 132 are collectively defined as the internal structure 13, the after-forming racket frame 11, first surface layer 12, second surface layer 14 and internal structure 13 are collectively defined as the ball hitting portion 10, and the ball hitting portion 10 and the handle portion 20 are collectively defined as the paddle tennis racket 1' (as shown in FIG. 6J).

[0023] The step S6: the end step: drill a plurality of through holes 15 in the ball hitting portion 10 of the paddle tennis racket 1', and wind the grip strap 21 on the handle portion 20.

[0024] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims, by which the invention shall be solely defined.

Claims

1. A manufacturing method of a paddle tennis racket (1'), the paddle tennis racket (1') comprising a ball hitting portion (10) and a handle portion (20) connected with the ball hitting portion (10), the ball hitting portion (10) comprising a racket frame (11), a first surface layer (12), a second surface layer (14) and an internal structure (13), the racket frame (11) having an inner wall (111) and an accommodating space formed in an encircled manner by the inner wall (111), the internal structure (13) being disposed in the accommodating space and comprising an upper core material layer (131), a lower core material layer (133) and a core rib sheet (132) piled between the upper core material layer (131) and the lower core material layer (133), the first surface layer (12) being laid on a top surface of the upper core material layer (131), the second surface layer (14) being laid on a bottom surface of the lower core material layer (133), the racket frame (11), the first surface layer (12), the second surface layer (14) and the core rib sheet (132) being all made of carbon fiber reinforced composite material, the first surface layer (12), the second surface layer (14) and the core rib sheet (132) being all integrally connected with the racket frame (11), the manufacturing method being characterized in comprising the steps of: providing a plurality of windable sheet materials (S) coated with resin, and an expandable material (F), the windable sheet materials (S) being made of carbon cloth; winding the windable sheet materials (S) coated with resin on exterior of the expandable material (F) to form a tube-shaped structure (T), the tube-shaped structure (T) having a first end portion (E1) and a second end portion (E2) opposite to the first end portion (E1); bending the tube-shaped structure (T) in a way that the tube-shaped structure (T) is formed with a frame (30) and a column (40) connected with the frame (30), an accommodating space (R) is formed in an encircled manner by an inner wall of the frame (30), and the first end portion (E1) and the second end portion (E2) are abutted upon each other linearly to be formed into the column (40); laying a lower composite sheet material, a lower core material layer (133), a first middle composite sheet material (17), a second middle composite sheet material (18), an upper core material layer (131) and an upper composite sheet material (19) in the accommodating space (R) in bottom-up order, bending an outer periphery of the first middle composite sheet material (17) downwardly to make the outer periphery of the first middle composite sheet material (17) attached between the inner wall of the frame (30) and the lower core material layer (133), and bending an outer periphery of the second middle composite sheet material (18) upwardly to make the outer periphery of the second middle composite sheet material (18) attached between the inner wall of the frame (30) and the upper core material layer (131), wherein the lower composite sheet material, the first middle composite sheet material (17), the second middle composite sheet material (18) and the upper composite sheet material (19) are all made of carbon cloth; the after-bending tube-shaped structure (T) and the after-laying lower composite sheet material, lower core material layer (133), first middle composite sheet material (17), second middle composite sheet material (18), upper core material layer (131) and upper composite sheet material (19) are collectively defined as a preformed member; pressurizing and heating the preformed member and expanding the expandable material (F) to make the column (40) heat cured and then formed into the handle portion (20), make the frame (30) heat cured and then formed into the racket frame (11), make the upper composite sheet material (19) heat cured and integrally connected with the racket frame (11) and then formed into the first surface layer (12), make the lower composite sheet material heat cured and integrally connected with the racket frame (11) and then formed into the second surface layer (14), and make the first middle composite sheet material (17) and the second middle composite sheet material (18) heat cured, integrally connected with each other and both integrally connected with the racket frame (11) and then collectively formed into the core rib sheet (132), so that the after-forming upper core material layer (131), lower core material layer (133) and core rib sheet (132) are collectively defined as the internal structure (13), the after-forming racket frame (11), first surface layer (12), second surface layer (14) and internal structure (13) are collectively defined as the ball hitting portion (10), and the ball hitting portion (10) and the handle portion (20) are collectively defined as the paddle tennis racket (1').

2. The manufacturing method as claimed in claim 1, which is characterized in that the upper core material layer (131) and the lower core material layer (133) are equal in thickness.

3. The manufacturing method as claimed in claim 1 or 2, which is characterized in that the upper core material layer (131) and the lower core material layer (133) are made of a same material.

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