JPH0525633Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a ball for ball games such as volleyballs and soccer balls, which has a cloth layer such as a woven fabric as a reinforcing layer.

<Conventional technology> The cross-sectional structure of the ball using the conventional technology includes the sixth
There are those shown in Figures 8 through 8. In both cases, a rubber hollow sphere tube 1 filled with compressed air, a cloth layer 2 for covering the tube surface and giving it sphericity and durability as a ball, and adhesiveness between the cloth layer 2 and the leather panel 3 are shown. A thin rubber layer 4 that improves the performance of the ball, a plurality of leather panels 3 that form the ball skin...
Consists of. These structural differences are due to the fabric layer 2
It is located at the sewn part of multiple cloth pieces that make up the sixth
What is shown in the figure is a thread 6 at the edge of the cloth pieces 5, 5.
The one shown in Fig. 7 is made by overlapping the stitched outer pieces 7, 7... of the cloth pieces 5, 5... and folded back in the same direction, and the one shown in Fig. 8 is made by overlapping stitches. , the sutured portion protrudes toward the tube 1 side. The structure shown in FIG. 8 is described, for example, in US Pat. No. 2,091,455. In addition, in the current products such as volleyballs, there are no fabric layers that are sewn together to form a reinforcing fabric layer, and most of them are made using thread-wound reinforcing layers (thousands of meters of nylon thread wrapped around a tube). layer) is used.

<Problems to be solved by the invention> Recently, especially in women's volleyball or boys' soccer games, it has been developed to reduce the pain felt when the ball collides with the ball.
There is a strong desire to create volleyballs and soccer balls that have a softer feel that better fits the hands and legs. However, with the current balls using thread-wound reinforcing layers, it is difficult to dramatically improve the soft feel. The inventors of the present invention discovered that a ball with a softer feel could be achieved by replacing the thread-wound layer with a cloth layer, that is, a structure in which multiple pieces of cloth such as woven fabric were sewn together to form a sphere, and a tube was housed in this. In reaching this goal, we conducted various studies regarding its specific structure.

The stitched fabric layer gives the ball a soft feel, but it also provides dimensional stability and
It also has the function of imparting sphericity and durability to the ball. However, with the ball having the structure shown in Fig. 6, compression tests (33° in the diameter direction of the ball)
% compression test), the limit is about 5000 to 6000 times, and at this point, 5 pieces of cloth are compressed at seam A.
Most of them were damaged to the extent that they were unusable, and the structure shown in Figures 7 and 8 had a limit of approximately 150,000 cycles.

The reason why the structures shown in FIGS. 6 to 8 are mechanically weak is considered to be as follows. That is,
This is because the fixing of the cloth pieces 5, 5 depends only on the suturing force of the thread 6. FIG. 9 shows a schematic enlarged view of FIG. 6 (an example in which the cloth pieces have a plain weave structure), and the internal pressure P applied from the tube (not shown) to the cloth pieces 5, 5... corresponds to this. A tensile force T is generated. This tensile force T becomes strong when the ball is kicked or bounced, but the warp threads a, a... of the cloth pieces 5, 5 are caused by the weft threads b, b... and the thread 6. Since it is only being pressed, it cannot withstand this huge tensile force T and is pulled out.

FIG. 10 shows a schematic enlarged view of FIG. 8, and the same thing as mentioned above can be said, and the suturing force of the thread 6 against the tensile force T is weak.

Furthermore, the structure shown in FIG.
The overlapping part and the protruding part of the thread 6 are the leather panel 3
Mirror through (a phenomenon that appears as unevenness on the ball surface) B and C occurs on the ball surface, making the ball surface unpleasant to the touch and causing a decrease in commercial value.

<Means for Solving the Problems> The present invention solves all of the above problems and provides a fabric layer seam portion with excellent durability.

The inventors of the present invention found that when the ball having the structure shown in FIG. The tear in the seam A is large, and on the contrary, the outer piece 7 of the seam
The present invention was developed by noting that the stitched portion D of the cloth piece 5 folded back by 180 degrees was hardly torn. That is, in the present invention, in order to increase the strength of the seamed portion of the cloth layer 2, the cloth pieces 5, 5...seamed portion outer piece 7,
7... were each folded back by 180 degrees toward the tube side, and the folded portions, that is, the pieces on the outside of the seam portion, were pressed against each piece of cloth by the internal pressure of the tube.

<Function> In FIGS. 1 and 11, the cloth pieces 5, 5 are
At the seam portion, the seam portion outer pieces 7, 7 are folded back by 180 degrees. In this folded part, tube 1
Since an internal pressure P is applied to the fabric layer, a predetermined tensile force T
At the same time, the outer pieces 7, 7 of the suture portion...
is pressed against the cloth pieces 5, 5... When the internal pressure P and tensile force T momentarily become strong, such as when playing a ball, the internal pressure P presses the warp threads a, a, etc., and prevents them from being pulled out by the tensile force T. Therefore, the stitching structure (referred to as ground stitching or split stitching) in such a seamed portion has a strength greater than the fixing force provided by the thread 6 alone, and prevents this portion from tearing. Further, the thickness of the cloth of the outer seam pieces 7, 7, . . . is absorbed by the deformation of the tube 1, and the spherical shape of the surface of the cloth pieces 5, 5, . . . is maintained.

<Example> In FIG. 1, reference numeral 1 denotes the aforementioned tube filled with compressed air, which is formed into a hollow sphere of rubber with low air permeability such as butyl rubber. A valve (not shown) for injecting air is fixed to this tube 1, and air is injected through the valve so that the internal pressure of the tube 1 is approximately 0.4 to 0.5 kg/cm ² (for volleyball). is injected.
2 is the above-mentioned cloth layer which covers the tube 1 and serves as a reinforcing layer. Twelve approximately rectangular cloth pieces 5, 5, etc. as shown in FIG. 2 are sewn together to form a spherical bag shape. It is something. The shape of the piece of cloth 5 is cut slightly larger than the size (indicated by the broken line) that can completely cover the surface of the tube 1, and a piece 7 on the outside of the seam part 7 is provided as a seam allowance of about 1 cm width. ing. The broken line portion is the suture line 8. The sides of the cloth piece 5 are curved slightly outward in order to lie along the spherical surface of the tube 1. The two cloth pieces 5, 5 having the same shape are sewn together by overlapping the cloth pieces 5, 5 and sewing the seam line 8 thereof using a sewing machine. As suture thread 6, 40 to 30
Thread with high tensile strength such as aramid fiber,
Nylon or polyester sewing thread is used, and the sewing pitch can be 1.5 mm.
The material of the cloth piece 5 is a cloth that has excellent physical properties such as tensile strength, bending strength, and elasticity that gives elasticity to the ball, especially a polyester/cotton blend (65%-35%, commonly known as gold cloth), 100% nylon. , 100% polyester can be used, and the number of threads (number of warp and weft threads per inch) is 30-30.
Fabrics ranging from 150 to 150 can be used.

The fabric is made of the above materials and thread counts.
It is possible to realize a bag-shaped fabric layer that can withstand the pressure applied by the tube and maintain its spherical shape. Also, the ratio of the number of threads per warp to the number of threads per weft is set to, for example, 30-30,
The stretch rate of the fabric is equal in the longitude and latitude directions of the ball.
Therefore the spherical shape is maintained for a long period of time.

As shown in FIG. 3, the pair of cloth pieces 5, 5 are sewn together on their longest sides to form a left-right symmetrical equilateral quadrilateral piece 9 via this central seam line. Six equilateral quadrilateral pieces 9 are formed in this way, and each center suture line is adjacent to the quadrilateral pieces 9, 9...
They are juxtaposed and sutured so that they are perpendicular to each other. In this way, the bag-shaped cloth layer 2 is formed by leaving only one short side of the cloth piece 5.
is formed. At this time, the stitched portion has a structure in which the stitched portion outer pieces 7, 7, . . . of the cloth pieces 5, 5, . . . protrude outward. Therefore, it is necessary to fold it back 180 degrees and fix it to the cloth pieces 5, 5, . . . .
This is done by applying an adhesive or adhesive such as urethane rubber adhesive, chloroprene rubber adhesive, natural rubber adhesive, etc. to the seam part, and manually folding back the outer pieces 7, 7... of the seam part. Pieces of cloth 5, 5...
This is done by fixing... After that,
The fabric layer 2 is turned over through the hole in the unsewn part of the short side of the fabric piece 5, and then the deflated tube 1 is stored.
The short sides are sutured.

Sewn outer pieces 7, 7 of cloth pieces folded back 180°
In order to fix ... in the folded state, it is possible to create two more suture lines parallel to the suture line in the center and fix the folded part.
Since there are three suture lines, it may cause deformation if the tensile strength of each suture line differs, and some of the threads making up the two suture lines may
Considering that the protrusion on the surface of the mirror may cause mirror through, the above-mentioned fixing method using an adhesive or adhesive is optimal. Note that the adhesive or pressure-sensitive adhesive can be applied by spraying, and only the area where the 180° folded cloth piece is fixed is sufficient.

FIGS. 4 and 5 show the completed state of the volleyball having the above-mentioned structure, and 4 is the aforementioned thin rubber layer called the middle layer formed by covering the cloth layer 2;
Reference numerals 3, 3, . . . are leather pieces having a thin portion around the periphery that are bonded onto the thin rubber layer 4 via an adhesive, and 18 pieces of approximately rectangular natural leather or synthetic leather are pasted together. Here, the shape of the leather pieces 3, 3... is different from the shape of the cloth pieces 5, 5.... Also leather pieces 3,3
The shape of ... is commonly used in design,
Since the leather pieces themselves do not have shape retention or elastic recovery, just because the leather pieces 3, 3... are shaped similar to the cloth pieces 5, 5... and are attached to the ball surface, this is the only effect. There is no improvement in dimensional stability or sphericity.

In addition, in order to reduce the weight of the ball, a thin rubber layer 4
Leather pieces 3, 3 are attached directly to the fabric layer 2 with adhesive.
... can also be attached.

<Effects of the invention> According to the invention, the cloth layer that acts as a reinforcing layer is made up of a plurality of pieces of cloth sewn together into a spherical shape, and the outer side of the stitched portion of each piece of cloth is folded back 180° toward the tube. Therefore, in addition to fixing the cloth piece with the thread, the pressure inside the tube can be used to strengthen the suturing force, and the strength of this sutured portion is significantly improved. With this structure, even after approximately 370,000 cycles of the compression test described above, no tears were observed in the seams of the cloth pieces.

Furthermore, according to the present invention, the outer piece of the stitched portion is folded back 180° toward the tube, and since the thickness of each piece of cloth is extremely thin, this folded portion does not appear on the ball surface as a mirror through. Similarly, since the sewing thread does not appear on the surface of the fabric layer, it does not cause mirror through.

Furthermore, according to the present invention, the material of the cloth layer is polyester/cotton blend, nylon, or polyester cloth, which has excellent physical properties such as tensile strength, bending strength, and elasticity that gives elasticity to the ball. Therefore, a ball having appropriate elasticity and excellent durability can be realized. In addition, the number of strokes of the cloth is in the range of 30-30 to 150-150, which is much larger than normal cloth (the number of strokes is about 15-20), and therefore the strength of the cloth is extremely high. This also greatly contributes to improved durability.

[Brief explanation of the drawing]

Figure 1 is a perspective view of essential parts of an embodiment of the present invention;
3 is a front view showing the appearance of the cloth layer, FIG. 4 is a front view showing the surface shape of the volleyball, and FIG. 5 is a front view showing the shape of the cloth layer.
The cross-sectional views, FIGS. 6 to 8 are cross-sectional views of conventional examples,
9 is an enlarged perspective view of the main part of Fig. 6, Fig. 10 is an enlarged perspective view of the main part of Fig. 8, and Fig. 11 is an enlarged perspective view of the main part of Fig. 1.
FIG. 2 is an enlarged perspective view of the main part of the figure. 1... Tube, 2... Fabric layer, 3, 3... Leather panel, 4... Rubber thin layer, 5, 5... Cloth piece, 7,
7... Outer piece of suture part, 8... Suture line.

Claims (1)

[Claims for Utility Model Registration] (1) A hollow rubber tube filled with compressed air, a fabric layer covering the surface of the tube to give the ball dimensional stability, sphericity, and durability;
In a ball game ball having a leather layer adhered directly or through a thin rubber layer on the cloth layer,
The above cloth layer is made of one of polyester/cotton blend, nylon, or polyester, and the number of strokes is 30-30 or more.
A plurality of pieces of cloth made of cloth in the range of 150-150 mm are sewn into a spherical shape, and the outer side of the stitched part of each cloth piece is folded back 180 degrees toward the tube, and the inner pressure of the tube causes the cloth to be sewn into a spherical shape. A ball game ball characterized in that it is pressed into two pieces (2) A utility model characterized in that the outer piece of the seamed portion is adhered or adhered to the opposing fabric layer with an adhesive or a pressure-sensitive adhesive. Ball for ball games as set forth in Claim 1 of the Registered Claims