JPS6036304B2 - Manufacturing method for leather-covered balls for ball games - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a leather-covered ball for ball games, and more specifically, a method for efficiently and reliably attaching leather to balls such as basketballs and handballs having rubber ribs (or channels) on the ball base. The present invention relates to a new manufacturing method for manufacturing.

As shown in FIGS. 1 and 2, a conventional leather-covered ball of this kind, for example, a leather-covered basketball, is made up of a hollow spherical rubber tube a equipped with an air injection valve f, and a
A reinforcing layer b made of thread, cloth, etc. and a rubber cover layer c are attached to the car and vulcanized and molded in a mold having rib grooves in a predetermined pattern to obtain a ball base having ribs d in a predetermined pattern on the surface. , has a structure in which each skin panel e made of natural leather, synthetic leather, etc., cut into a shape corresponding to the partition pattern formed by the ribs d, is stuck in each partition surrounded by the ribs d.

Until now, in the manufacture of leather-covered balls having the above-mentioned structure, there has been no industrially superior method for attaching a skin panel over the metal surface to the surface of a ball base having ribs.

Conventionally, the method of attaching leather to this type of ball was to attach adhesive-applied skin panels E one by one to the surface of the section surrounded by ribs D, without leaving any gaps, to achieve an excellent appearance. I was making a ball.However, this method is
There were drawbacks such as a considerable amount of manpower and time being required, the efficiency of the leather pasting process being extremely poor, and the workers involved in the leather pasting process requiring a high degree of skill. In order to improve the above method, Hakama Kosho No. 52-4307 proposes a method in which the entire surface is simultaneously pasted within the mold.

This method uses a hemispherical mold that has partition ridges and a large number of intake holes on its inner surface, and attaches a skin panel with a thin periphery to the compartment formed by the partition ridges by suction from the intake holes. A ball base without ribs is housed in a mold made by combining these into a spherical shape, and internal pressure is applied inside the ball base while suction is simultaneously applied from the air intake holes to remove the rubber layer on the outer surface of the base from around the skin panel. This is a method in which the rubber is extruded to the outside and thickened to the dividing protrusions on the inner surface of the mold, and a thin part of the outer periphery of the skin panel is crimped to the side surface of the extruded rubber part. However, this method has many drawbacks for the reasons described below, and is difficult to adopt as a production process.In other words, in the above method, the rubber layer on the outer surface of the ball base is pushed out from the periphery of the skin panel to the outer surface of the ball to form partition protrusions. At the same time as the outer surface of the skin panel is brought into contact with Because of the presence of the ridges that are the main purpose, when suctioning and layering a flat skin panel on the inner surface of a mold, it is extremely difficult to suction and layer it completely three-dimensionally up to the ridges. It is difficult to achieve leather bonding and strong adhesion in a short time with just one step as in the method using rubber-based adhesives, and furthermore, ``Leather-covered balls taken out in only one step, Partial peeling off of small rocks and the surrounding area of the skin panel, or running onto ribs, is likely to occur, and it is rare to obtain a finished product with a beautiful appearance.The present invention was made in view of the above-mentioned circumstances. The purpose is to provide a method that eliminates all of the above-mentioned drawbacks, and that can industrially produce leather-covered balls with a beautiful appearance at high production efficiency.

As a result of the inventor's intensive research, the above-mentioned object of the present invention is basically to not only simultaneously attach the skin panel to the ball base but also to increase the adhesive strength between the skin panel and the ball base so as to cover the entire surface. By adding a heating and pressing process that gives an ironing effect, and as a mold used in the simultaneous adhesion process, we have created a guide channel consisting of two protrusions that form grooves that correspond to the rib pattern on the surface of the ball base. A hemispherical mold with a spherical inner surface and an intake hole in the area surrounded by the guide channel is used, while the mold used for the heating and pressing process is This is accomplished by using a hemispherical heating mold with patterned ridges that can be pressed.

In other words, "The method for producing a leather-covered ball for ball games according to the present invention is as follows:
Basically, the area surrounded by the guide channel of a spherical mold having a guide channel corresponding to the protruding rib pattern on the surface of the ball base on the inner surface has substantially the same size as the area and the peripheral area thereof. After layering a large number of thin skin panels, the ball base is positioned and housed in the mold so that the protruding ribs are aligned with the guide channels, and the internal pressure of the ball base is The surface of the ball base is pressed against the skin panel, and the entire skin is applied to the entire area surrounded by the protruding ribs of the ball base through the adhesive applied in advance to at least one of the back surface of the skin panel or the surface of the pole base. First step of simultaneously pasting the panels; inside a spherical mold formed with protrusions formed at least in an area adjacent to the area corresponding to the protrusion ribs of the ball base ~ the leather-attached ball obtained in the first step is positioned and housed so that the protruding ribs correspond to the protruding ribs, the mold is heated and at the same time the internal pressure of the leather-covered ball is increased, and the protruding ribs of the spherical mold are used to The present invention is characterized in that it includes a second step of performing the adhesion process on the skin panel again while increasing the pressing force of the ball base against the skin panel.

The most preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

First, a reinforcing layer 4 is layered uniformly on the entire surface of a hollow spherical rubber tube, such as a butyl rubber tube 3, using yarn, cloth, etc., such as nylon twisted yarn, and a cover layer 5 made of natural rubber is molded on top of the reinforcing layer 4, and rib grooves are formed. The ball base 1 having the structure shown in FIGS. 3 and 4 is obtained by vulcanization molding using a mold having the same structure as in the conventional method.

Thereafter, a rubber adhesive is applied to the surface of the obtained ball base 1 and preliminarily dried. Note that it is advantageous to make the top surface of the protruding rib 2 concave as shown in FIG. 4, since this makes it easier to fit in the hand during competitions and prevents slipping. On the other hand, as shown in Figure 5, the natural leather or synthetic leather that will become the outer skin panel is cut to a predetermined size, the surrounding area is scraped off to a predetermined thickness, and a rubber adhesive is applied to the back side (see Figure 5). Apply to the entire surface (lower surface) and pre-dry.

As shown in Figure 6, the mold used in the process of simultaneously pasting the skin panel and the ball base is a hemispherical mold that is divided into upper and lower halves, and the pins 9 and pin holes 10 match the upper and lower parts accurately. Use mold 8 (one hemispherical mold is not shown)
.

A multi-segmented mold is also possible, but this is not preferable because the operation becomes complicated. The spherical inner surface of the hemispherical mold 8 has a diameter somewhat larger than the outer periphery of the ball base 1 shown in FIG. A guide channel 11 consisting of two protrusions 13, 13' forming a ridge is provided, and a large number of air intake holes 14 are bored in each area defined by the guide channel 11, which communicates with the air intake chamber 15. The intake chamber 15 is connected to a vacuum pump (not shown) via an intake pipe 16. Here, if we show the relationship between the protruding rib 2 on the surface of the ball base 1 and the guide channel 11 of the hemispherical mold 8 (see FIGS. 4 and 7), we can see that the inner radius of the protruding rib 2 and the concave groove are The relationship with W in 12 is WZ
R, the relationship between the height T of the rib 2 and the depth of the groove 12 is preferably HZT, and the thickness of the two protrusions 13, 13' of the guide channel 11 is In terms of the appearance of the ball, it is preferable that the rib be smaller than 0.5 ribs.

Furthermore, the relationship between the thickness P of the circumferential twill portion of each skin panel 7 and the height h of the two-striped protrusions 13, 13' from the inner surface of the mold is h<
It is necessary that there is a relationship of P. In the first leather pasting step (simultaneous pasting step), a vacuum is applied to the skin panel 7 in the area defined by the guide channel 11 so that its front surface is in contact with the spherical inner surface of the mold 8. The skin panels 7 are arranged one after another while being suctioned, and all the skin panels 7 are suctioned and layered on the spherical inner surface of the mold 8, as shown in FIG. A skin panel is similarly placed on the spherical inner surface of the upper mold by suction. Here, each skin panel 7 is pupiled without displacement within each area defined by the guide channel 11 of the hemispherical mold 8. Next, after the hemispherical mold with the skin panels arranged in this way, the ball base 1 is inserted into the concave groove 12 of the guide channel 11 provided with the protruding rib 2 on the inner surface of the mold. Afterwards, the mold 8 is closed to form a spherical shape, and high pressure air is injected into the ball base 1 through the air injection valve 6 attached to the ball base 1.
The surface of each skin panel 7 is pressed against the back surface of each skin panel 7, and each skin panel 7 is adhered to the ball base 1.

Thereafter, the internal pressure of the ball base 1 is removed and the ball is taken out, and as shown in FIG. get the ball. An air injection needle is attached to the air injection valve 6 to inject air into the ball base through the needle, and an insertion hole for inserting the needle is provided at a predetermined position in the hemispherical mold. Just set it up. The above process is a process of attaching the entire skin panel to the ball base and performing preliminary adhesion.

However, in this first step alone, the chicks in each skin panel,
There is a lack of three-dimensional effect (insufficient ironing effect) due to unevenness and insufficient pressing of the seams (periphery of each panel), and due to unsolidified rubber adhesive, there may be peeling or full surface damage due to partial lifting around each skin panel. Insufficient adhesive strength is unavoidable due to the nature of the adhesive. In order to solve these problems, the following second step (heating and pressing step) is performed.

That is, as shown in FIGS. 10 and 11, the structure is such that the periphery of each skin panel can be particularly strongly compressed, and the ball base 1 has a bisected ridge 18 that is wider than the ridge rib 2 of the ball base 1. Hemispherical heating mold 17 (see FIG. 10) or two parallel pattern protrusions 19, 19 that can particularly press the peripheral area of the skin panel 7 near the protrusion ribs 2 of the ball base 1.
A hemispherical heating mold 17' (see FIG. 11) having a shape of 17' is prepared for manufacture. Next, the ball that has undergone the first step is inserted into the hemispherical heating mold 17 or 17', the heating mold 17 or 17' is closed to form a spherical shape, and the air injection valve 6 is passed into the ball base 1. The first step is completed by applying a higher internal pressure (approximately 6 to 9 kg') than in the first step by injecting air and heating the hemispherical heating mold 17 or 17' in an appropriate manner. After applying a high temperature (approximately 40 to 90 oo) to the ball to strengthen the adhesion between each skin panel 7 and the ball base 1 and giving an ironing effect to the entire surface, the internal pressure inside the ball base 1 is reduced. The mold is opened, and a leather-covered ball that is durable and has a beautiful appearance is taken out. As described above, the method of the present invention separates the pasting process of leather-covered balls into two steps, a simultaneous pasting process and a heating and pressurizing process, and uses a mold that is used in the simultaneous pasting process to form a mold on the surface of the ball base. A hemispherical mold having a guide channel consisting of two protrusions forming grooves corresponding to the striped rib pattern on the inner surface of the mold and an air intake hole in the area defined by the guide channel is used. By using the double protrusions to guide the positioning of the skin panels, suction layering of each skin panel onto the inner surface of the mold can be done quickly, reliably, and extremely easily.

In addition, by performing a heating and pressing process in addition to the above simultaneous adhesion process, the adhesive force can be strengthened, so there is no partial peeling around the skin panel, and the adhesive is melted and solidified uniformly over the entire surface of the sphere. Since an ironing effect can be imparted, there is no occurrence of squeaks and the feel of the ball is also excellent. By combining these two processes, it is possible to produce leather-covered balls with excellent durability and a beautiful appearance with kudzu production efficiency.

[Brief explanation of the drawings] Figure 1 is a side view of the leather-covered basketball, and Figure 2 is the side view of the leather-covered basketball.
FIG. 3 is a side view of the ball base; FIG. 4 is an enlarged cross-sectional view taken along the line X-Y in FIG. 3; FIG. 5 is a perspective view of the skin panel; The figure is a longitudinal cross-sectional view showing an example of a hemispherical mold used in the simultaneous pasting process of the method of the present invention, Figure 7 is an enlarged cross-sectional view of the Z section in Figure 6, and Figure 8 is a simultaneous pasting process of the present invention method. A partial cross-sectional explanatory view showing how the ball base is inserted into the hemispherical mold in the process, FIG. 9 is a partial cross-sectional view of the ball after the simultaneous adhesion process, and FIG. FIG. 11 is a partial cross-sectional view showing the relationship between the hemispherical heating mold and the ball, and FIG. 11 is a partial cross-sectional view showing the relationship between another mold and the ball. 1 is a ball base, 2 is a protruding rib, 7 is a skin panel, 8 is a hemispherical mold, 11 is a guide channel, 12 is a groove, 13,
13' is a double protrusion, 14 is an intake hole, 17 and 17' are hemispherical heating molds, and 18, 19, and 19' are pattern protrusions. Figure 1 Figure 2 Figure 3 Figure 4 Figure 7 Figure 10 Figure 5 Figure 6 Figure 8 Figure 9 Figure 11

Claims (1)

[Scope of Claims] 1. A spherical mold having a guide channel corresponding to the protruding rib pattern on the surface of the ball base on its inner surface, the area surrounded by the guide channel having substantially the same size as the area and After arranging a large number of skin panels with thin peripheral parts, the ball base is positioned and housed in the mold so that the protruding ribs match the guide channels, and the internal pressure of the ball base is increased. The surface of the ball base is pressed against the skin panel, and the entire skin panel is simultaneously applied to the entire area surrounded by the protruding ribs of the ball base through the adhesive applied in advance to at least one of the back surface of the skin panel or the surface of the ball base. First step of adhering: The leather-covered ball obtained in the first step is placed in a spherical mold having a protrusion formed at least in an area adjacent to the area corresponding to the protrusion rib of the ball base. Positioned and housed so that the ribs correspond to the protrusions,
At the same time as heating the mold, the internal pressure of the leather-covered ball is increased, and the skin panel is bonded again with the protrusion of the spherical mold increasing the pressing force of the ball base against the skin panel in the vicinity of the protrusion rib. A method for manufacturing a leather-covered ball for ball games, comprising: a second step of performing treatment. 2. The method for producing a leather-covered ball for ball games according to claim 1, wherein the guide channel is comprised of two protrusions forming grooves corresponding to the protrusion rib pattern on the surface of the ball base. 3 In the first step, the skin panel is placed in the mold by forming a large number of minute air intake holes in each area of the mold's inner surface divided by guide channels, and drawing air through the air intake holes to draw the skin panel into the mold. A method for manufacturing a leather-covered ball for ball games according to claim 1, characterized in that the manufacturing method is carried out by adhering the panel to the wall surface of a mold. 4. The leather-covered ball for ball games according to claim 1, wherein the heating temperature and internal pressure of the leather-covered ball by the mold in the second step are set higher than those values in the first step. manufacturing method.