JP7738426B2 - Blanks and handles - Google Patents

Description

This invention primarily relates to the structure of a blank that serves as a component of a fishing rod, as well as a fishing rod handle equipped with this blank.

In this specification, the term "fishing rod" includes not only a fishing rod used to operate a fishing tackle or reel in a fish that has been hooked, but also, for example, the handle of a fishing rod used to reel in a fish that has been hooked.

Fishing rods generally consist of multiple blanks, which are connected longitudinally via a predetermined joint structure. At fishing spots, there are obstacles (typically large, protruding reefs) that can obstruct the angler's ability to use the fishing rod, and in some cases, the fishing rod may come into contact with such obstacles. For example, when reef fishing, the angler reeles in a fish by extending the dipstick handle and scooping it up with a dip net attached to the handle. During this process, the dip net and dipstick handle used to scoop up the fish can be buffeted by swells along the reef, causing the dip net to be smashed against the reef and break or break off. When such an accident occurs, the angler loses not only the dipstick handle, but also the fish and dip net. This can be a serious tragedy, especially if the fish caught in the dip net is large, and can also cause psychological shock.

To prevent accidents such as fishing rod breakage, a fishing rod needs to be designed with practical mechanical strength and reinforcement to prevent damage, so that it will not be easily damaged when colliding with an obstacle. However, because fishing rods are generally made of so-called CFRP, even if strength is improved to a certain extent by designing a thicker structure, there is a limit to how much strength can be increased. Furthermore, since the fishing rod handle must be designed to be light enough that a fisherman operating the fishing rod with one hand can use the other, there is an upper limit to the allowable weight, making it unrealistic to construct the fishing rod handle out of metal, for example. In other words, it is extremely difficult to design a fishing rod that will prevent damage.

Although it has been difficult to prevent damage to the fishing rod handle, methods have been proposed to prevent damaged fishing rod handles from breaking apart (see, for example, Patent Document 1). The fishing rod disclosed in Patent Document 1 has a breakage prevention filament wound in a spiral shape when the prepreg is wound around the mandrel during blank molding. It is said that the breakage prevention filament prevents the blank molded in this way from breaking apart even if it is damaged.

Patent No. 2659580

The orientation of the fibers contained in the prepreg plays an important role in determining the practical mechanical strength of the blank. That is, it is important that the fibers run in a uniform manner around the circumferential direction of the molded blank (the formation of a so-called "reverse grain" layer), and these reverse grain layers are generally arranged in the innermost and outermost layers of the blank.

In the fishing rod disclosed in the above-mentioned document, the anti-splitter filaments are arranged in a spiral pattern above or below the prepreg (between the mandrel and the prepreg). In other words, the anti-splitter filaments are arranged adjacent to the barbed layer on the outside or inside. As a result, during pressure molding, the anti-splitter filaments cause the fibers extending circumferentially of the blank to displace and meander in different directions, drastically reducing the practical strength of the molded blank.

The primary objective of the present invention is to provide a lightweight blank that can prevent a decrease in practical mechanical strength while avoiding fragmentation even if damaged.

(1) The blank according to the present invention comprises a first fiber-reinforced resin layer provided radially inward and having reinforcing fibers extending circumferentially; a second fiber-reinforced resin layer provided radially outward from the first fiber-reinforced resin layer and having reinforcing fibers extending circumferentially; and an intermediate layer provided between the first and second fiber-reinforced resin layers and having anti-severance wires extending axially.

The intermediate layer forms the core of the blank as a structure. A first fiber-reinforced resin layer and a second fiber-reinforced resin layer are arranged radially inside and outside this intermediate layer, respectively, forming what is known as a barbed layer. It is important that the reinforcing fibers contained in the first fiber-reinforced resin layer and the second fiber-reinforced resin layer are aligned circumferentially to achieve a predetermined strength (mainly bending strength); if these reinforcing fibers are displaced anisotropically or meander, the mechanical strength of the blank will decrease.

In this invention, the anti-splitter wire is embedded in the blank, so even if the blank is damaged, it will not split into multiple pieces. In addition, the anti-splitter wire is located between the first and second fiber-reinforced resin layers and extends axially so as to be covered by the intermediate layer. Therefore, when the blank is fired, the anti-splitter wire prevents the reinforcing fibers from displacing anisotropically or meandering, preventing a decrease in the mechanical strength of the blank.

(2) The intermediate layer may contain reinforcing fibers extending in the axial direction.

This configuration improves the axial tensile strength of the blank, thereby improving the bending strength of the blank as a structure.

(3) The intermediate layer may contain reinforcing fibers extending in the circumferential direction.

This configuration improves the circumferential tensile strength of the blank. Therefore, the torsional strength of the blank as a structure is further improved.

(4) The intermediate layer may contain reinforcing fibers extending in a direction intersecting the axial direction.

This configuration further improves the buckling (crushing) strength of the blank as a structure.

(5) The intermediate layer may include an inner intermediate layer radially inward from the anti-severance wire and an outer intermediate layer radially outward from the anti-severance wire.

In this configuration, the anti-splitter wire is embedded in the intermediate layer. This reliably maintains the circumferential alignment of the reinforcing fibers contained in the first and second fiber-reinforced resin layers. Therefore, when the blank is fired, the anti-splitter wire reliably prevents the reinforcing fibers from displacing anisotropically or meandering.

(6) It is preferable that at least one of the inner intermediate layer and the outer intermediate layer contains reinforcing fibers extending in the axial direction.

This configuration improves the axial tensile strength of the blank, thereby improving the bending strength of the blank as a structure.

(7) It is preferable that at least the other of the inner intermediate layer and the outer intermediate layer contains reinforcing fibers extending in the circumferential direction.

This configuration improves the circumferential tensile strength of the blank. Therefore, the torsional strength of the blank as a structure is further improved.

(8) It is preferable that at least one of the inner intermediate layer and the outer intermediate layer contains reinforcing fibers extending in a direction intersecting the axial direction.

This configuration further improves the buckling (crushing) strength of the blank as a structure.

(9) It is preferable that at least the other of the inner intermediate layer and the outer intermediate layer contains reinforcing fibers extending in the axial direction.

This configuration improves the axial tensile strength of the blank, thereby improving the bending strength of the blank as a structure.

(10) It is preferable that at least the other of the inner intermediate layer and the outer intermediate layer contains reinforcing fibers extending in the circumferential direction.

This configuration improves the circumferential tensile strength of the blank. Therefore, the torsional strength of the blank as a structure is further improved.

(11) It is preferable that the reinforcing fibers contained in the inner intermediate layer and the outer intermediate layer extend in directions that intersect with each other.

This configuration further improves the axial and circumferential tensile strength of the blank. This further improves the bending strength, torsional strength, and buckling strength of the blank as a structure.

(12) It is preferable that the anti-severance wire extends spirally along the axial direction.

In this configuration, the anti-splitter wire further improves the mechanical strength of the blank as a structure.

(13) A ball handle can be constructed using the blank.

According to this invention, anti-splitter wire is provided in the middle layer that forms the core of the blank, preventing the reinforcing fibers that form the so-called reverse grain layer from displacing anisotropically or meandering during blank molding. This maintains the practical mechanical strength of the blank and, ultimately, the ball handle made from this blank, while preventing it from splintering even if it is damaged.

FIG. 1 is a perspective view showing the appearance of a ball handle according to one embodiment of the present invention. FIG. 2 is a diagram showing a cross-sectional structure of a blank that constitutes a ball handle. FIG. 3 is an enlarged view of the main part in FIG. FIG. 4 is a diagram showing a schematic diagram of the manufacturing process of the blank. FIG. 5 is a diagram showing a schematic diagram of the manufacturing process of the blank. FIG. 6 is a diagram showing a schematic diagram of the manufacturing process of the blank. FIG. 7 is a diagram showing a schematic diagram of the manufacturing process of the blank. FIG. 8 is a diagram showing a schematic diagram of the manufacturing process of the blank. FIG. 9 is a diagram showing a schematic diagram of the manufacturing process of the blank. FIG. 10 is an enlarged cross-sectional view of a part of a ball handle according to another embodiment of the present invention. FIG. 10 is a diagram schematically illustrating a cross-sectional structure of a blank according to a design modification example of one embodiment of the present invention.

A preferred embodiment of the present invention will be described below, with appropriate reference to the drawings. It goes without saying that this embodiment is merely one aspect of the bead handle of the present invention, and that modifications may be made without departing from the spirit of the present invention.

<Structure of the ball handle>

Figure 1 is an external perspective view of a ball handle 10 according to one embodiment of the present invention. This figure shows the ball handle 10 in use.

As shown in the diagram, the landing net 12 is attached to the fishing handle 10, and the two are used assembled together during actual fishing. That is, the fishing handle 10 is extendable along the axial direction 21, and the landing net 12 is detachably attached to the tip of the fishing handle 10. When landing a fish, the angler extends the fishing handle 10 and uses the landing net 12 to scoop up any fish that have been caught.

The landing net 12 has a net body 13 and a frame 14 that supports it. The frame 14 has a shaft 16, which is formed with a male thread 15. This shaft 16 is screwed onto the tip of the landing net handle 10, and the landing net 12 is fixed to the landing net handle 10.

The hilt 10 has four blanks 17-20 (hilt body 11), which are joined together in a so-called retractable fashion. That is, the blanks 17-20 are cylindrical, with the largest-diameter blank 20 having the other blanks 19, 18, and 17 nested inside it. When the hilt 10 is in use, the blanks 17-19 are pulled out of the blank 20 in the axial direction 21, with blank 17 positioned at the very tip of the hilt body 11. In this embodiment, the hilt body 11 is made up of four blanks 17-20, but there are no particular restrictions on the number of blanks that make up the hilt body 11.

A female thread is formed on the inside of the tip of the blank 17, and a cap 23 is fitted around the tip. The female thread may be formed directly on the inner surface of the blank 17, or, for example, a sleeve may be fitted inside the tip and the female thread may be formed on this sleeve. The male thread 15 is threaded onto this female thread, and the landing net 12 is removably attached to the landing net handle 10. The cap 23 is made of, for example, rubber, and its outer shape is shaped so that it can be removably fitted into the tip of the blank 20. A butt plug 22 is provided at the rear end of the blank 20. This butt plug 22 has a known structure and is removably threaded onto the blank 20.

Figure 2 is a diagram showing a schematic cross-sectional structure of blank 17. Figure 3 is an enlarged view of a key portion of Figure 2.

The blank 17 is made of resin and has a cylindrical outer shape. The resin used to form the blank 17 is generally a thermosetting resin (typically epoxy resin), and the cylindrical blank 17 is formed by heat treatment, as described below. This resin is preferably reinforced with fiber. Carbon fiber is generally used as the fiber reinforcing the resin, but glass fiber or other fibers may also be used. Note that the blanks 18-20 are also made of resin, just like the blank 17. The outer shape of each blank 17-20 is designed to form a predetermined taper. The outer diameter of each blank 17-20 is smallest at the tip end (left side in Figure 1) in the axial direction 21 and gradually increases toward the rear end (right side in Figure 1). The outer diameter of the rear end of the blank 17 is set larger than the inner diameter of the tip end of the blank 18. Therefore, the blank 17 placed inside the blank 18 fits into the blank 18 when pulled out of the blank 18 along the axial direction 21. For the other blanks 18-20, the relationship between adjacent blanks is similar to that of blanks 17 and 18.

As shown in Figures 2 and 3, the peripheral wall 24 of the blank 17 has a four-layer structure. That is, from the inside along the radial direction of the blank 17, a first fiber-reinforced resin layer 31, an intermediate layer 33, a second fiber-reinforced resin layer 32, and a surface coating layer 34 are laminated and integrally formed. The first fiber-reinforced resin layer 31 and the second fiber-reinforced resin layer 32 are respectively disposed on the inside and outside of the radial direction of the blank 17, with the intermediate layer 33 sandwiched between them. A breakage prevention wire 35 is provided in this intermediate layer 33.

The first fiber-reinforced resin layer 31 according to this embodiment is made of epoxy resin and is reinforced using carbon fiber as the reinforcing fiber. However, it goes without saying that thermosetting resins other than epoxy resin may also be used. In this embodiment, the carbon fibers contained in the first fiber-reinforced resin layer 31 extend along the circumferential direction of the blank 17. In other words, the first fiber-reinforced resin layer 31 forms a so-called barbed layer. The second fiber-reinforced resin layer 32 according to this embodiment also has the same composition as the first fiber-reinforced resin layer 31 and is made of epoxy resin or the like reinforced with carbon fiber. The second fiber-reinforced resin layer 32 is also a barbed layer, and the carbon fibers contained in the second fiber-reinforced resin layer 32 extend along the circumferential direction of the blank 17.

The intermediate layer 33 according to this embodiment forms the core of the blank 17 as a structure. The intermediate layer 33 is made of epoxy resin and is reinforced using carbon fiber as the reinforcing fiber. Other thermosetting resins may be used instead of epoxy resin for the resin constituting the intermediate layer 33. The carbon fibers contained in the intermediate layer 33 extend along the axial direction 21. In other words, the intermediate layer 33 forms a so-called forward grain layer. However, the carbon fibers contained in the intermediate layer 33 may also extend along the circumferential direction of the blank 17. In this case, the intermediate layer 33 forms a reverse grain layer. The carbon fibers contained in the intermediate layer 33 may also extend in a direction intersecting the axial direction 21 of the blank 17.

However, the carbon fibers contained in the intermediate layer 33 may extend in two different directions. That is, some of the carbon fibers may extend along the circumferential direction of the blank 17, and other portions may extend along the axial direction 21 of the blank 17, forming a lattice. Furthermore, some of the carbon fibers may intersect with the axial direction 21 at an angle (θ), while other portions may intersect with the axial direction 21 at an angle (-θ). In other words, some of the carbon fibers and other portions may extend in directions that intersect symmetrically with respect to the axial direction 21 of the blank 17, and be arranged in a lattice pattern. Note that the intermediate layer 33 does not have to contain carbon fibers or other reinforcing fibers.

A distinctive feature of the fishing rod handle 10 according to this embodiment is that the intermediate layer 33 includes a severance prevention wire 35. The severance prevention wire 35 is typically a twisted yarn made up of multiple polyethylene fibers. In other words, a type of fishing line known as "PE line" can be used. However, the material for the severance prevention wire 35 is not particularly limited; aramid fiber or metal (preferably a shape-memory alloy) can also be used as long as sufficient tensile strength (approximately 80 kgf/mm2) is ensured. Shape-memory alloys include titanium-nickel alloys and iron-manganese-silicon alloys. The severance prevention wire 35 extends straight from the leading end to the trailing end of the blank 17 along the axial direction 21. The severance prevention wire 35 is positioned within the intermediate layer 33 during the formation of the blank 17, as described below, and is therefore firmly attached to the intermediate layer 33 in the formed blank 17.

The surface coating layer 34 is formed by applying a specific paint to the outer surface of the molded blank 17. Epoxy and/or urethane paints can be used as this paint.

As shown in Figure 3, the thickness 36 of the blank 17 is the sum of the thicknesses 37-40 of the first fiber-reinforced resin layer 31, the second fiber-reinforced resin layer 32, the intermediate layer 33, and the surface coating layer 34. The thickness 37 of the first fiber-reinforced resin layer 31 is set to 0.02 mm to 0.30 mm, the thickness 38 of the second fiber-reinforced resin layer 32 is set to 0.02 mm to 0.30 mm, the thickness 39 of the intermediate layer 33 is set to 0.15 mm to 1.50 mm, and the thickness 40 of the surface coating layer 34 is set to 0.02 mm to 0.50 mm. These thicknesses 37-39 are set appropriately depending on the strength design of the blank 17. In this embodiment, the outer diameter of the anti-severance wire 35 is set to approximately 0.7 mm, but can be set appropriately within the range of 0.15 mm to 1.50 mm to correspond to the thickness 39 of the intermediate layer 33. In other words, the anti-severance wire 35 is embedded in the intermediate layer 33.

Blanks 18-20 have the same structure as blank 17. However, because the handle body 11 is connected in a telescopic fashion, the outer and inner diameters of each blank 18-20, as well as the thicknesses 37-39 of the first fiber-reinforced resin layer 31, second fiber-reinforced resin layer 32, and intermediate layer 33, are designed appropriately.

<Blank manufacturing method>

Each blank 17-20 is formed in the following manner. Figures 4 to 9 are diagrams that schematically show the manufacturing process for blank 17.

The blank 17 is manufactured by heat-treating (curing) the prepreg wrapped around the mandrel and then removing the mandrel. In other words, the blank 17 is manufactured through the following steps: (1) cutting process, (2) rolling process, (3) taping process, (4) heat-treating process, (5) core removal and tape removal process, and (6) finishing and cutting process.

(1) Cutting process

The prepreg is a sheet in which the reinforcing fibers (carbon fibers in this embodiment) are impregnated with resin. An example of the resin is epoxy resin. The mechanical strength of the blank 17 is determined by the tensile modulus of the reinforcing fibers. As shown in Figure 4, this prepreg 41 is cut to predetermined dimensions to form a cross pattern 42. In this embodiment, the cross patterns 42 corresponding to the first fiber-reinforced resin layer 31, the second fiber-reinforced resin layer 32, and the intermediate layer 33 are cut. The dimensions and shape of the cross pattern 42 are determined according to the length, outer diameter, rigidity, and other mechanical strength factors of the blank 17.

(2) Rolling process

As shown in Figure 5, the cross pattern 42a that forms the first fiber-reinforced resin layer 31 (see Figure 3) is positioned relative to the mandrel 43 and completely wrapped around the mandrel 43. At this time, the carbon fibers contained in the cross pattern 42a are wound along the circumferential direction of the mandrel 43 (the same direction as the circumferential direction of the molded blank 17). In this embodiment, the cross pattern 42a is a single sheet, but multiple cross patterns 42a may be wound around the mandrel 43 so that they are overlapping, depending on the strength design of the blank 17.

As shown in FIG. 6, the cross pattern 42b forming the intermediate layer 33 (see FIG. 3) is wound overlapping the cross pattern 42a. At this time, the carbon fibers contained in the cross pattern 42b are wound along the axial direction of the mandrel 43 (the same direction as the axial direction 21). Additionally, the anti-splitter wire 35 is arranged straight on the cross pattern 42a along the axial direction 21. In this embodiment, the cross pattern 42b is cut to make a complete circle around the outside of the cross pattern 42a (see FIG. 3). Therefore, the edges of the cross patterns 42b face each other circumferentially on the cross pattern 42a, and the anti-splitter wire 35 is arranged to be sandwiched between the edges of the cross pattern 42b, as shown in FIG. 3. Alternatively, the cross pattern 42b may be cut to overlap the cross pattern 42a. In FIG. 6, the cross pattern 42b is a single sheet, but multiple cross patterns 42b may be wound overlapping each other depending on the strength design of the blank 17.

In this embodiment, the cross pattern 42b is wound around the mandrel 43 so that the carbon fibers extend along the axial direction 21. However, the cross pattern 42b may also be wound so that the carbon fibers extend along the circumferential direction or a direction intersecting the axial direction 21. Furthermore, when multiple cross patterns 42b are wound, the carbon fibers may be wound to form a lattice. For example, one cross pattern 42b may be wound around the mandrel 43 so that the carbon fibers extend along the axial direction 21, and another cross pattern 42b may be wound around the mandrel 43 so that the carbon fibers extend along the circumferential direction. Furthermore, one cross pattern 42b may be wound around the mandrel 43 so that the carbon fibers intersect with the axial direction 21 at an angle (θ), and another cross pattern 42b may be wound around the mandrel 43 so that the carbon fibers intersect with the axial direction 21 at an angle (-θ). The cross patterns 42b may not necessarily contain carbon fibers.

As shown in Figure 7, the cross pattern 42c that forms the second fiber-reinforced resin layer 32 (see Figure 3) is wound so that it overlaps the cross pattern 42b. At this time, the carbon fibers contained in the cross pattern 42c are wound along the circumferential direction of the mandrel 43. In this embodiment, the cross pattern 42c is a single sheet, but similar to the cross patterns 42a and 42b, multiple cross patterns 42c may be wound overlapping each other.

(3) Taping process

As shown in Figure 8, tape 45 is wrapped around the cross pattern 42 to prevent the cross pattern 42 from peeling off from the mandrel 43. This tape 45 is made of, for example, polypropylene, and is wrapped around the cross pattern 42 and mandrel 43 to fasten them together.

(4) Heat treatment process

As shown in Figure 9(a), the tubular and taped cross pattern 42 is placed in a furnace 46 together with a mandrel 43. This furnace is typically an electric oven, and the cross pattern 42 is heated, for example, in an atmosphere of 140°C for 120 minutes. This causes the epoxy resin contained in the cross pattern 42 to harden while being reinforced by the carbon fibers, and a lightweight blank 17 with excellent tensile strength and bending strength is baked.

(5) Core removal and tape removal process

Once the heat treatment process is complete, the mandrel 43 is pulled out of the blank 17, as shown in Figure 1(b). The tape 45 is removed from the fired blank 47.

(6) Finishing and cutting process

The cylindrically formed blank 17 is cut to a predetermined length. The surface of the blank 17 is polished and the required paint is applied. This paint forms the surface coating layer 34.

The other blanks 18-20 are manufactured in a similar manner. The cap 23 is attached to the leading end of blank 17, and the butt plug 22 is attached to the trailing end (see Figure 1). These processes are well known, so a detailed description will be omitted.

<Effects of the ball handle>

The blanks 17-20 manufactured in this manner are joined in a telescopic fashion to form the handle body 11. As shown in Figure 1, a landing net 12 is attached to the handle body 11, and the angler can use the net 12 to scoop up fish by manipulating the handle body 11. In this landing net handle 10, as shown in Figure 3, the middle layer 33 is sandwiched between the first and second fiber-reinforced resin layers 31 and 32, which are barbed layers. Therefore, the carbon fibers contained in the first and second fiber-reinforced resin layers 31 and 32 ensure sufficient strength (mainly bending strength) of the blanks 17-20, allowing the angler to comfortably operate the landing net handle 10 during actual fishing.

Even if the handle body 11 hits a rocky shore during actual fishing, the breakage prevention wire 35 embedded in the intermediate layer 33 prevents the blanks 17-20 from breaking apart, even if they are damaged. This prevents the blanks 17-20 from breaking and separating, resulting in the loss of the landing net 12 and the fish scooped up by the net 12. Furthermore, the breakage prevention wire 35 is covered by the intermediate layer 33, positioned between the first fiber-reinforced resin layer 31 and the second fiber-reinforced resin layer 32, and extends in the axial direction 21. Therefore, when the blanks 17-20 are fired, the breakage prevention wire 35 prevents the carbon fibers contained in the first fiber-reinforced resin layer 31 and the second fiber-reinforced resin layer 32 from displacing anisotropically or meandering. As a result, the incorporation of the breakage prevention wire 35 into the intermediate layer 33 prevents a decrease in the mechanical strength of the blanks 17-20.

When the carbon fibers contained in the intermediate layer 33 extend in the axial direction 21, i.e., when the intermediate layer 33 forms a forward-grain layer, the tensile strength of the blanks 17-20 in the axial direction 21 is improved. Therefore, the bending strength of the blanks 17-20 is improved. Furthermore, when the carbon fibers contained in the intermediate layer 33 extend in the circumferential direction, i.e., when the intermediate layer 33 forms a reverse-grain layer, the tensile strength of the blanks 17-20 in the circumferential direction is improved. Therefore, the torsional strength of the blanks 17-20 is further improved. Furthermore, when the carbon fibers contained in the intermediate layer 33 extend in a direction intersecting the axial direction 21, the buckling (crushing) strength of the blanks 17-20 is further improved.

<Other embodiments>

Figure 10 is an enlarged cross-sectional view of a portion of a ball handle 50 according to another embodiment of the present invention.

The ball handle 50 according to this embodiment differs from the ball handle 10 in that the intermediate layer 51 is divided into an inner intermediate layer 52 and an outer intermediate layer 53, sandwiched between the anti-severance wire 35. The remaining configuration of the ball handle 50 is the same as that of the ball handle 10.

As shown in Figure 10, the peripheral wall 24 of the blanks 17-20 that make up the ball handle 50 has a five-layer structure. That is, from the inside out along the radial direction of the blanks 17-20, the first fiber-reinforced resin layer 31, the inner intermediate layer 52, the outer intermediate layer 53, the second fiber-reinforced resin layer 32, and the surface coating layer 34 are layered and integrally formed. The separation prevention wire 35 is located at the boundary between the inner intermediate layer 52 and the outer intermediate layer 53. However, the separation prevention wire 35 only needs to be located at the intermediate layer 51, and the center of the separation prevention wire 35 does not have to be located at the boundary between the inner intermediate layer 52 and the outer intermediate layer 53.

The inner intermediate layer 52 is formed using the same process as the intermediate layer 33 of the ball handle 10. That is, the inner intermediate layer 52 consists of a single or multiple cross patterns, and the carbon fibers reinforcing the inner intermediate layer 52 are arranged in the circumferential direction (left and right in the figure), the axial direction 21 (the direction perpendicular to the paper surface in the figure), or a direction intersecting the axial direction 21. In particular, when the inner intermediate layer 52 consists of multiple cross patterns, the carbon fibers may be arranged to form a lattice.

The outer intermediate layer 53 is also formed using the same process as the intermediate layer 33 and consists of a single or multiple cross patterns. The carbon fibers reinforcing the outer intermediate layer 53 are arranged along the circumferential direction, the axial direction 21, or a direction intersecting the axial direction 21. As with the inner intermediate layer 52, when the outer intermediate layer 53 consists of a multiple cross pattern, the carbon fibers may be arranged to form a lattice.

The direction of the carbon fibers reinforcing the inner intermediate layer 52 and the outer intermediate layer 53 is selected appropriately depending on the strength design of the blanks 17-20.

For example, in the design of blanks 17-20, the carbon fibers in either or both of the inner intermediate layer 52 and the outer intermediate layer 53 are arranged so that they extend along the axial direction 21. This design improves the tensile strength of blanks 17-20 in the axial direction 21, and improves the bending strength of blanks 17-20 as structures.

Furthermore, when the carbon fibers in at least one of the inner intermediate layer 52 and the outer intermediate layer 53 are arranged so that they extend along the circumferential direction of the blanks 17-20, the carbon fibers are arranged in a lattice pattern, improving the tensile strength of the blanks 17-20 in the circumferential direction. This further improves the torsional strength of the blanks 17-20.

In the design of blanks 17-20, the carbon fibers in either or both of the inner intermediate layer 52 and the outer intermediate layer 53 may be arranged so that they extend in a direction that intersects with the axial direction 21. In particular, it is preferable that the direction of the carbon fibers contained in the inner intermediate layer 52 intersects the direction of the carbon fibers contained in the outer intermediate layer 53. This design improves the buckling (crushing) strength of blanks 17-20.

<Example of design changes>

Figure 11 is a diagram showing the cross-sectional structure of blanks 17 to 20 according to design modifications of the above embodiments.

In blanks 17-20 according to this design modification example, the anti-severance wire 35 extends spirally along the axial direction 21. By winding the anti-severance wire 35 around blanks 17-20 in this way, the mechanical strength of blanks 17-20 as structures is further improved.

DESCRIPTION OF SYMBOLS 10: Bead handle 11: Handle body 17: Blank 18: Blank 19: Blank 20: Blank 21: Axial direction 31: First fiber reinforced resin layer 32: Second fiber reinforced resin layer 33: Intermediate layer 35: Severance prevention wire 50: Bead handle 51: Intermediate layer 52: Inner intermediate layer 53: Outer intermediate layer 54: Edge 55: Edge

Claims (2)

A ball handle having a blank made of a plurality of resin layers,
The blank is
A first fiber reinforced resin layer provided radially inside and containing reinforcing fibers extending in the circumferential direction;
A second fiber reinforced resin layer provided radially outside the first fiber reinforced resin layer and containing reinforcing fibers extending in the circumferential direction;
an intermediate layer having one anti-severance wire extending along the axial direction, adjacent to the first fiber reinforced resin layer and the second fiber reinforced resin layer, and provided between the first fiber reinforced resin layer and the second fiber reinforced resin layer;
The intermediate layer is
an inner intermediate layer located radially inward of the anti-severance wire;
an outer intermediate layer radially outward from the anti-severance wire;
One of the inner intermediate layer and the outer intermediate layer contains reinforcing fibers extending in the axial direction,
The other of the inner intermediate layer and the outer intermediate layer contains reinforcing fibers extending in the circumferential direction. The ball handle according to claim 1 , wherein the anti-breakage wire is disposed between the edges of the inner intermediate layer and between the edges of the outer intermediate layer.