How billiard cues are manufactured

Abstract

To manufacture a billiard cue capable of solving the problems of a shaft of the conventional billiard cue where vigorously hitting a cue ball in a predetermined direction and using the shaft for a long period of time are slightly difficult and strange sound is caused by use for a long time.SOLUTION: A billiard cue manufacturing method includes: providing a hollow hole on a shaft of a billiard cue; as a core material to be inserted thereto, manufacturing a pipe made from fiber-reinforced composite material having a structure having partially different rigidity in a longer direction and composed of glass fibers and carbon fibers whose rigidity difference is large, using integral molding for performing bonding and molding at the same time; manufacturing a core material having foam synthetic resin buffer material filled in a hollow of the pipe and inserting the core material into the hollow hole of the shaft; and fixing the wooden shaft and a wooden bat using a detachable device.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a billiard cue consisting of a shaft and a butt. In particular, the present invention relates to a method for manufacturing a billiard cue shaft that has good controllability over the bending of the shaft when the ball is struck, and has an internal structure that will not break even after long-term use and does not emit abnormal noises to the outside. [Background technology]

[0002] A conventional billiard cue has six pillar-shaped pieces of wood cut into a sector-shaped (pie-shaped) cross section inserted in the longitudinal direction of the hollow part of the shaft (see Patent Document 1: JP-A-11-502428).

[0003] However, with the billiard cue shaft described in JP 11-502428 A, there was a problem in that it was somewhat difficult to bend and control the shaft when striking the cue ball with the tip of the shaft, making it difficult to strike the cue ball forcefully in the desired direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 11-502428 Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention is to solve the above problems and to invent a method of manufacturing a billiard cue that allows the cue ball to be struck in a predetermined direction with a predetermined force when struck with the tip of the shaft. The invention also relates to a method of manufacturing a billiard cue having a billiard cue shaft whose internal structure will not break even after long-term use and which does not emit abnormal noises to the outside. [Means for solving the problem]

[0006] In the present invention, a hollow hole is created in the shaft of a billiard cue and a core material is inserted. The core material is made of two materials with different strength and flexibility, namely glass fiber and carbon fiber, which are fibers with a large difference in rigidity. A pipe made from these fiber-reinforced composite materials is integrally molded and the hollow space inside the pipe is filled with a foamed synthetic resin cushioning material. By attaching this wooden shaft and wooden butt with a detachable device, it has been possible to manufacture a billiard cue with an internal structure that will not break even with long periods of use and that will not emit abnormal noises to the outside.

[0007] The present invention relates to product The present invention relates to a method for producing a billiard cue having the structure described in the following (A) to (C). (A) A billiard cue comprising a wooden shaft having a cylindrical tapered shape with a hollow hole with a circular cross section that runs from the tip to the rear end, and a wooden butt attached with a detachable device, the wooden shaft having a core material inserted therein, the core material being formed by arranging and stacking prepregs of a short glass fiber reinforced plastic, a long carbon fiber reinforced plastic, and a long glass fiber reinforced plastic in the hollow hole of the shaft so that, from the tip, they appear in that order, with the hollow space filled with a long piece of foamed synthetic resin cushioning having a circular cross section. (B) A billiard cue, comprising a wooden shaft having a cylindrical tapered shape with a hollow hole with a circular cross section that runs from the tip to the rear end, and a wooden butt attached with a detachable device, the wooden shaft having a core material inserted therein, the core material being formed by arranging and stacking prepregs of a long glass fiber reinforced plastic, a long carbon fiber reinforced plastic, and a short glass fiber reinforced plastic in that order from the tip to form an integral fiber reinforced composite pipe, the hollow space inside which is filled with a long length of foamed synthetic resin with a circular cross section. (C) A billiard cue, comprising a wooden shaft having a cylindrical tapered shape with a hollow hole with a circular cross section that runs from the tip to the rear end, and a wooden butt attached with a detachable device, the wooden shaft having a core material inserted therein, the core material being formed by arranging and stacking prepregs of a long carbon fiber reinforced plastic in the center and a short glass fiber reinforced plastic at each end to form a fiber reinforced composite pipe into which a long foamed synthetic resin with a circular cross section has been filled. The meaning of "appearance-wise" above is that, as described in claims 1 and 2 of the scope of claims of the present invention, when manufacturing a fiber-reinforced composite pipe, a glass fiber prepreg sheet, which has a relatively short width, is wrapped around a mandrel (core rod) and laminated, but because the glass fiber prepreg sheet and glass fiber reinforced plastic are transparent or translucent, from the outside, the carbon fiber reinforced plastic (black) underneath appears to be parallel to the carbon fiber reinforced plastic.

[0008] The above (A) and (B) product A method for producing the above-mentioned compound is described. The following steps (1) to (5): (1) A cylindrical, tapered wooden shaft is provided with a hollow hole with a circular cross section that runs from the tip to the back end. (2) Separately, a carbon fiber prepreg sheet having a relatively short width and a glass fiber prepreg sheet having a relatively long width are each impregnated with the same type of thermosetting resin into carbon fiber and glass fiber, which are fibers having different rigidities. The carbon fiber prepreg sheet and the glass fiber prepreg sheet are wound around a metal mandrel (core rod) having a circular cross section in such an arrangement that the widths of the glass fiber prepreg sheet portions protruding from both ends of the carbon fiber prepreg sheet are different lengths, and then a synthetic resin tape is wrapped around the outside of the entire structure, and the entire structure is heated and hardened while being pressed to make it tightly and dense, thereby forming an integral structure in which bonding and molding are performed simultaneously. After that, the mandrel is pulled out, the tape is peeled off, and the outside is shaved to a size such that the outer diameter can be fitted into the hollow hole of the wooden shaft produced in the above step (1), thereby producing an integrally molded fiber-reinforced resin composite pipe having a circular cross section and a structure in which the rigidity in the longitudinal direction is partially different. (3) Filling the hollow of the fiber-reinforced resin composite pipe with a foamed synthetic resin cushioning material to produce a core material; (4) The core material is inserted into the hollow hole of the wooden shaft produced in the above step (1), (5) The wooden shaft and the wooden butt are attached with a detachable device. A method for manufacturing a billiard cue, comprising the steps of: The above "glass fiber prepreg sheet width" is the one with the shorter length facing the tip of the shaft. product (A), and the longer width is directed toward the tip of the shaft. product The answer is (B). By using the same fiber-reinforced resin composite pipe at the end upside down as the core material, the flexibility and usability of the shaft can be easily adjusted, which is convenient.

[0009] The above (C) product A method for producing the above-mentioned compound is described. The following steps (1) to (5): (1) A cylindrical, tapered wooden shaft is provided with a hollow hole with a circular cross section that runs from the tip to the back end. (2) Separately, a carbon fiber prepreg sheet having a relatively short width and a glass fiber prepreg sheet having a relatively long width are each impregnated with the same type of thermosetting resin into carbon fiber and glass fiber, which are fibers having different rigidity. The carbon fiber prepreg sheet and the glass fiber prepreg sheet are wound around a metal mandrel (core rod) having a circular cross section in such an arrangement that the widths of the glass fiber prepreg sheet portions protruding from both ends of the carbon fiber prepreg sheet are the same length, and then a synthetic resin tape is wrapped around the outside of the entire structure, and the entire structure is heated and hardened while being pressed to closely and densely adhere thereto, thereby forming an integral structure in which bonding and forming are performed simultaneously. After that, the mandrel is pulled out, the tape is peeled off, and the outside is shaved to a size such that the outer diameter fits into the hollow hole of the wooden shaft produced in the above step (1), thereby producing an integrally molded fiber reinforced resin composite pipe having a circular cross section and a structure in which the rigidity in the longitudinal direction is partially different. (3) Filling the hollow of the fiber-reinforced resin composite pipe with a foamed synthetic resin cushioning material to produce a core material; (4) The core material is inserted into the hollow hole of the wooden shaft produced in the above step (1), (5) The wooden shaft and the wooden butt are attached with a detachable device. A method for manufacturing a billiard cue, comprising the steps of: Effect of the Invention

[0010] The billiard cue manufactured by the manufacturing method of the present invention, which is the product described in (A) to (C) above, has one feature in that it has a wooden shaft having a core material inserted therein, "a core material characterized by being formed by filling a foamed synthetic resin cushioning material into the hollow space of an integrally molded fiber-reinforced composite pipe." In this way, the core material of the wooden shaft is manufactured so that a long foamed synthetic resin cushioning material is filled in from the tip, which cushions the impact on the wooden part of the shaft when in use, prevents damage to the wooden part of the shaft, allows the billiard cue to be used stably for a long period of time, and does not generate abnormal noises to the outside, even when the billiard cue is used for a long period of time. Furthermore, in the present invention, the carbon fiber reinforced plastic core material and the glass fiber reinforced plastic at both ends are manufactured using prepregs impregnated with the same type of thermosetting resin, which are wrapped around a mandrel to form a laminate; therefore, when the entire structure is wrapped with synthetic resin tape in the next process and pressurized to make it tightly packed and densified, the same type of resin blends together and may become somewhat mixed together; therefore, when the entire structure is heated and hardened, the same type of thermosetting resin also acts as an adhesive, and it is possible to manufacture an integrated mold that performs bonding and molding simultaneously (without using any other adhesives). Therefore, it is possible to produce a core material having a strongly integrated structure with different stiffness in the longitudinal direction. The inventors had previously used pre-formed reinforced plastic pipes (finished products) as the core material, and fixed a short carbon fiber reinforced plastic pipe to the inside of a glass fiber reinforced plastic pipe with an adhesive, thereby producing and using a core material with partially different longitudinal rigidity. However, since the pre-formed pipes were glued afterwards, it was difficult to position them as desired, and the adhesive would peel off while the billiard cue was in use, causing problems such as abnormal noises and a lack of quality stability, such as flexing. The core material produced by the present invention is strong because it is a one-piece molded product that is molded and bonded simultaneously, rather than being glued in later, and it has the advantage that positioning is easy because it is performed at the prepreg stage.

[0011] Here, taking the above product (A) as an example, the effect during actual use will be described. When the cue ball is struck, the first thing that the billiard cue does to the cue ball is the short, integrally molded glass fiber reinforced plastic at the tip, but because glass fiber reinforced plastic has less rigidity than carbon fiber reinforced plastic, the impact it gives to the wooden shaft is small, allowing the billiard cue to be used stably for a long period of time. Professionals and advanced billiard players can then lightly and stably hold the shaft for a short period of time, allowing them to strike the cue ball with a relatively small amount of force at first. Furthermore, professionals and advanced players can take advantage of the properties of long, highly rigid carbon fiber reinforced plastic to strike the cue ball with great force, causing the shaft to bend significantly. This rebound force creates a strong pushing force on the cue ball as it tries to return to its original shape, allowing them to hit the cue ball hard with a combined force that includes the pushing force of the arm used to strike the billiard cue (see Figure 3). Also, beginners in billiards are initially unable to hit the cue ball in the desired direction, and therefore are unable to use the flexibility of the shaft to curve the cue ball in the intended direction, but gradually become able to hit the cue ball so that it curves in the intended direction. In this case, the core of the shaft is filled with foamed synthetic resin cushioning, which prevents beginners from damaging the wooden shaft, and also has the effect of not making any abnormal noises outside, even when the billiard cue is used for a long time, as the foamed synthetic resin cushioning absorbs sound.

[0012] As described above, the billiard cue manufactured by the present invention has the advantage that the length of the glass fiber reinforced plastic core material can be easily adjusted by the manufacturing method of the present invention, and therefore it can be controlled to suit the experience, technique, and preference of beginners, professionals, and advanced billiard players. Furthermore, the manufacturing method of the present invention allows the shaft core material, carbon fiber reinforced plastic and glass fiber reinforced plastic, to be molded as a single unit, making it strong. In addition, since the tip of the shaft is filled with a long foamed synthetic resin cushioning material with a circular cross section, it cushions the impact on the wooden part of the shaft when in use and prevents damage to the wooden part of the shaft, which has the effect of allowing the billiard cue to be used stably for a long period of time, and also has the effect of not generating abnormal noises to the outside, even when the billiard cue is used for a long period of time, since the cushioning material absorbs sound.

[0013] As mentioned above, by using the high-strength core material produced by the one-piece molding of the present invention, there is an advantage in that there is a greater degree of freedom in terms of shaft hardness and taper fineness. When the end faces of each molded reinforced plastic (molded product) were later glued together, cracks would appear in the adhesive when the shaft flexed, resulting in frequent malfunctions. However, the integrally molded product produced by this invention has improved strength, so malfunctions are virtually eliminated. Currently, users tend to prefer shafts with a thin taper, but the new, high-strength, one-piece molded material produced by this invention makes it possible to manufacture shafts with a thinner taper than ever before, and by making the taper thinner, it has the advantage that defects are less likely to occur even if more flex occurs.

[0014] The wood used for the shaft in the present invention may be any of the woods normally used for shafts (eg, maple, ebony, rosewood, etc.).

[0015] The mandrel (core rod) used in the present invention is known to be made of metal, resin, ceramic, and the like, but from the viewpoint of productivity, metal is preferred.

[0016] Known reinforcing fibers include organic fibers such as carbon fiber, glass fiber, and aramid fiber, and inorganic fibers such as silicon carbide fiber. In the present invention, it is preferable to use a combination of carbon fiber and glass fiber in order to increase the difference in rigidity.

[0017] Examples of the thermosetting resin used in the present invention include epoxy resins, polyester resins, vinyl ester resins, phenolic resins, and polyurethane resins, with epoxy resins being particularly preferred. The temperature and time for heat curing vary depending on the type of resin, but for example, when an epoxy resin is used, it is preferable to heat and cure it at 130 to 140 degrees (°C) for about two hours.

[0018] Examples of materials for the synthetic resin tape include polypropylene, polyethylene, polyester, cellophane, and polyimide. From the viewpoint of a good balance of the tape shape, it is preferable to use polypropylene and polyester. The pressure applying means may be in the form of a tube such as a heat shrink tube or a rubber tube, in addition to a tape.

[0019] Examples of foamed synthetic resins that can be used as the cushioning material in the present invention include foamed polyethylene, foamed polystyrene, foamed polypropylene, and foamed polyurethane, with foamed polyethylene and foamed polyurethane being particularly preferred.

[0020] To explain the "flexibility" of the shaft when it is in use, "flexibility" occurs when the ball is struck with a billiard cue. When the shaft flexes, the ball's rotation speed increases. When comparing the bending of the "glass fiber reinforced plastic" and "carbon fiber reinforced plastic" in this invention, the glass fiber reinforced plastic is softer (less rigid) and more flexible. However, the flex performance that can be achieved throughout the shaft will vary depending on the various combinations of factors such as the length and position of the glass fiber reinforced plastic, the length and position of the carbon fiber reinforced plastic, and the narrowness of the shaft taper. As a general trend for shafts, as the carbon fiber reinforced plastic gets longer, it becomes harder and less flexible, and as the carbon fiber reinforced plastic gets shorter and the shaft taper gets thinner, the flexibility increases. Here, an example of "curving the cue ball" using flexibility will be explained with reference to Figure 3. For example, to bend the cue ball 31 to the left of its center line 32, the properties of the glass fiber reinforced plastic of the shaft and the slightly stronger long carbon fiber reinforced plastic can be used to strike the cue ball with a slightly large force at a position (strike point 34A) to the right of center line 32 passing through the center 33 of the cue ball 31, as shown in Figure 3. Then, as the tip of the shaft bends to the right, the cue ball can be bent to the left. In this case, as shown in Figure 7, the shaft bends significantly (35) and generates a force pushing the cue ball diagonally to the left, so that this force pushing the cue ball diagonally to the left combines with the force of the arm used to strike the billiard cue, allowing the cue ball to be hit hard and curved with great force. Please note that Figure 3 is an explanatory diagram of the force vectors caused by the bending of the shaft when it is in use, and the relative sizes of the cue ball and shaft in the diagram are different from those in the actual situation. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a plan view of a billiard cue manufactured according to the present invention. [Diagram 2] 1 is an enlarged cross-sectional view of various portions of a shaft manufactured according to the present invention. [Diagram 3] FIG. 2 is an explanatory diagram of a shaft manufactured according to the present invention in use. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The present invention will be described in more detail below with reference to examples. However, the technical scope of the present invention should not be construed as being limited to the contents of these examples. EXAMPLES

[0023] (1) As shown in FIG. 1, a billiard cue 6 consists of a wooden shaft 1 and a wooden butt 5. The wooden shaft 1 is cylindrical and tapered, and has a hollow hole 1A with a circular cross section that runs through it from the tip to the back end. (2) Separately, a carbon fiber prepreg sheet having a relatively short width and a glass fiber prepreg sheet having a relatively long width were each impregnated with the same epoxy resin using carbon fiber and glass fiber, which are fibers with different rigidity. The carbon fiber prepreg sheet was then wrapped around a thin, cylindrical metal mandrel (core rod) with a circular cross section. Next, one to three glass fiber prepreg sheets were wound on top of the carbon fiber prepreg sheet in such an arrangement that the width of the glass fiber prepreg sheet portion protruding from the carbon fiber prepreg sheet was short on one side and long on the other. After that, while applying tension, polypropylene resin tape was wrapped around the outside of the entire sheet, and pressure was applied to make it tightly and densified. The entire sheet was then heated at 130 to 140 degrees for approximately two hours to harden it, and a one-piece molding was performed in which bonding and molding were performed simultaneously. After the temperature had cooled, the mandrel was removed, the tape was peeled off, and the outside was shaved down to a size such that the outer diameter would fit into the hollow hole of the wooden shaft produced in step (1) above, producing an integrally molded fiber-reinforced resin composite pipe with a circular cross-section and a structure in which the rigidity in the longitudinal direction is partially different. (3) Filling the hollow space of the fiber-reinforced resin composite pipe with a shock-absorbing material made of foamed polyethylene to produce a core material; (4) The core material is inserted into the hollow hole of the wooden shaft produced in the above step (1), (5) The wooden shaft and the wooden butt are attached with a detachable device. The billiard cue having a billiard cue shaft with a structure that has good controllability of the bending of the shaft when a ball is struck, does not break even when used for a long time, and does not emit abnormal noise to the outside is manufactured by carrying out the steps consisting of the steps. [Industrial Applicability]

[0024] The present invention focuses on two materials with different strengths and flex effects, namely glass fiber and carbon fiber, which are fibers with a large difference in rigidity, as the core material to be inserted into a hollow hole in the shaft of a billiard cue, and uses these to manufacture a fiber-reinforced composite pipe with a structure in which the rigidity in the longitudinal direction is partially different, by one-piece molding, which simultaneously performs bonding and molding, and manufactures a core material in which the hollow of the pipe is filled with a foamed synthetic resin cushioning material and inserted into the hollow hole in the shaft. By attaching this wooden shaft and wooden butt with a detachable device, it is possible to manufacture and provide a billiard cue with good flex controllability, an internal structure that will not break even with long periods of use, and a structure that does not emit abnormal noises to the outside. Therefore, the present invention has great industrial applicability. [Explanation of symbols]

[0025] 1 Wooden shaft 5. Wooden bat 6 Billiard cues (whole) 1A Wooden shaft hollow hole 2 G Fiber Reinforced Plastic 3 mosquito Carbon fiber reinforced plastic 4 Departure Synthetic foam cushioning 31 cue ball 32 Line passing through the center of the cue ball 33 Center of the cue ball 34A Point of impact when the cue ball is struck 35 Shaft flex (image) 36 Force vector when hitting the cue ball

Claims

1. The following steps (1) to (5): (1) A cylindrical, tapered wooden shaft is provided with a hollow hole having a circular cross section that runs from the tip to the rear end. (2) Separately, a carbon fiber prepreg sheet having a relatively short width and a glass fiber prepreg sheet having a relatively long width are each formed by impregnating carbon fiber and glass fiber, which are fibers having different rigidities, with the same type of thermosetting resin, and are wound around a metal mandrel (core rod) having a circular cross section in such an arrangement that the widths of the glass fiber prepreg sheet portions protruding from both ends of the carbon fiber prepreg sheet are different lengths, and then a synthetic resin tape is wrapped around the outside of the entire structure, and the entire structure is heated and hardened while being pressed to closely and densely adhere thereto, thereby forming an integral structure in which bonding and forming are performed simultaneously. Thereafter, the mandrel is pulled out, the tape is peeled off, and the outside is shaved to a size such that the outer diameter fits into the hollow hole of the wooden shaft produced in the above step (1), thereby producing an integrally molded fiber-reinforced resin composite pipe having a circular cross section and a structure in which the rigidity in the longitudinal direction is partially different. (3) Filling the hollow of the fiber-reinforced resin composite pipe with a foamed synthetic resin cushioning material to produce a core material; (4) The core material is inserted into the hollow hole of the wooden shaft produced in the above step (1), (5) The wooden shaft and the wooden butt are attached with a detachable device. A method for manufacturing a billiard cue, comprising the steps of:

2. The following steps (1) to (5): (1) A cylindrical, tapered wooden shaft is provided with a hollow hole having a circular cross section that runs from the tip to the rear end. (2) Separately, a carbon fiber prepreg sheet having a relatively short width and a glass fiber prepreg sheet having a relatively long width are each formed by impregnating carbon fiber and glass fiber, which are fibers having different rigidities, with the same type of thermosetting resin, and are wound around a metal mandrel (core rod) having a circular cross section in such an arrangement that the widths of the glass fiber prepreg sheet portions protruding from both ends of the carbon fiber prepreg sheet are the same length, and then a synthetic resin tape is further wrapped around the outside of the entire structure, and the entire structure is heated and hardened while being pressed to closely and densely adhere thereto, thereby forming an integral structure in which bonding and forming are performed simultaneously. Thereafter, the mandrel is pulled out, the tape is peeled off, and the outside is shaved to a size such that the outer diameter fits into the hollow hole of the wooden shaft produced in the above step (1), thereby producing an integrally molded fiber-reinforced resin composite pipe having a circular cross section and a structure in which the rigidity in the longitudinal direction is partially different. (3) Filling the hollow of the fiber-reinforced resin composite pipe with a foamed synthetic resin cushioning material to produce a core material; (4) The core material is inserted into the hollow hole of the wooden shaft produced in the above step (1), (5) The wooden shaft and the wooden butt are attached with a detachable device. A method for manufacturing a billiard cue, comprising the steps of:

3. 3. The method for manufacturing a billiard cue according to claim 1, wherein the thermosetting resin is one selected from the group consisting of epoxy resin, polyester resin, vinyl ester resin, phenolic resin, and polyurethane resin.

4. The method for manufacturing a billiard cue according to any one of claims 1 to 3, wherein the winding is performed by first winding a carbon fiber prepreg sheet around a mandrel and then winding one or more glass fiber prepreg sheets on top of the carbon fiber prepreg sheet, or by first winding a glass fiber prepreg sheet around a mandrel, then winding a carbon fiber prepreg sheet on top of the glass fiber prepreg sheet, and then winding one or more glass fiber prepreg sheets on top of the carbon fiber prepreg sheet.

5. The method for manufacturing a billiard cue according to any one of claims 1 to 4, wherein the foamed synthetic resin is one selected from the group consisting of foamed polyethylene, foamed polystyrene, foamed polypropylene, and foamed polyurethane.

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