JPS63147481A - Production of balling ball - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a bowling ball having a two-part structure including an inner core and an outer skin covering the inner core.

[Conventional technology and its problems] Bowling balls are generally required to have two characteristics. In other words, when a pole hits a pin, the impact force that acts in the direction of knocking down other pins without causing the pin to jump up, and the spin (twist) applied to the pole by the contestant are reliably transmitted to the pole, causing the pole to It is necessary to have an appropriate hook effect that curves in the direction desired by the player.

Of these characteristics, the former is influenced by the repulsive force of the pole, and the latter is influenced by the frictional resistance between the pole and the lane, resulting in a large j1! It is desirable that the poles roll in close contact with the lane due to frictional resistance.

Since the above characteristics are affected by the material of the bowling ball, there have been inventions related to improving the material (Japanese Patent Application Laid-open No. 59-2783 and No. 59-22584).
.

However, in order to improve the latter of the above characteristics, it is necessary not only to improve the material, but also to uniformly cover the inner core with an outer skin so that the ball as a whole is balanced.

Conventionally, the outer shell of a bowling ball was formed by a process as shown in Fig.
5).

That is, a stem 2 is attached to an inner core l formed into a spherical shape (a), and the inner core l is fixed in a shaping mold consisting of an upper mold 3a and a lower mold 3b via the stem 2, and then the filling port 4 is fixed. Inject and fill the outer skin material b) to form the outer skin 5. Once the outer skin material has hardened, remove the upper mold 3a and take out the pole body with the outer skin 5 formed.C) Stem 2 protruding from the outer skin 5. At the same time, the surface is polished and shaped to obtain the desired bowling ball (
d).

Note that 6 is a top weight that is attached when a hole (not shown) is made to reduce the weight of that part and also to help rotate the pole.

Normally, bowling balls are thrown onto a lane made of hard material such as maple, and are subjected to considerable impact. Therefore, sufficient adhesion between the outer shell and the inner core is required to withstand this impact. To provide impact resistance, the skin material that fills the mold is injected under high pressure. Therefore, in the case of conventional methods, the inner core becomes secondary due to the pressure.
As shown in Figure (C), the bowling ball is eccentric and the outer skin is not uniformly formed around the inner core, resulting in a bowling ball having a non-uniform outer skin as shown in Figure (d).

When a bowling ball like this rolls on the lane,
It does not rotate uniformly, but moves while swinging, creating a trajectory that is contrary to Polar's will, and not being able to obtain a sufficient hook effect, making it impossible to knock down the bottle using Polar's technique, resulting in the outcome of the game being lost. This means that it depends on chance.

That is, in the conventional method of manufacturing a bowling ball, when the inner core is fixed in the mold, it is supported by a single stem, which causes this problem.

[Means for Solving the Problems] It is an object of the present invention to provide a method for manufacturing a bowling ball that solves the above problems. The stem is fixed in a floating state in the center of the mold, and the outer skin material is filled into the mold, and after hardening, it is taken out from the mold, and the stem protruding from the formed outer skin is cut out, and the entire stem is removed. It is characterized by shaping and forming a hole.

[Function] When the inner core is fixed in the center of the mold by the stems attached at opposite positions, and the outer skin material is injected and hardened, the outer skin is uniformly formed around the inner core.

[Embodiment] An embodiment of the present invention will be described below with reference to FIG. 1 of the attached drawings. Note that the same reference numerals are used for the same parts as in the description of the conventional example above.

The stems 2a and 2b are attached to upper and lower opposing positions of the spherical inner core l with the top weight 6 attached to the top (a
), the stems 2a and 2b are inserted and fixed at the respective stem fixing positions provided on the upper mold 3a and the lower mold 3b,
Inject the outer skin material with pressure through the filling port 4 of the upper mold 3a b). When the filled outer skin material cools and hardens, remove the upper mold 3a and take out this pole body from the lower mold 3b. The stems 2a and 2b protruding from the surface of the outer skin 5 are removed.

The entire outer shell 5 is polished, and a hole (not shown) is formed in the top weight 6 to obtain the intended bowling ball.

The materials used for the inner core, outer skin, and top weight used in the present invention can be those used in the production of known bowling balls, and the stem 2
The material of a and 2b is preferably the same as the outer skin material.

In this embodiment, one stem is provided above and below the inner core.

The order and number are not limited to these, in short, it is sufficient as long as the inner core is reliably positioned in the center of the upper and lower molds and the inner core does not move due to the pressure when filling the outer skin material. .

[Effect] The method for manufacturing a bowling ball according to the present invention having the above configuration fixes the inner core at the center of the mold using a plurality of stems, and when filling the outer skin material, the position of the inner core can be controlled by the injection pressure. Since this does not change, the outer skin is uniformly formed around the inner core, and since the outer skin material can be filled with pressure, sufficient adhesion between the outer skin and the inner core can be obtained.

In summary, in the present invention, since the outer skin is uniformly formed around the inner core, a bowling ball with a well-balanced weight can be obtained, and a hook effect corresponding to the poler's technique is produced on the pole, making it easier to use as a competitive bowling ball. It has many advantages such as increasing the fun, improving the level of polling competitions, and contributing to popularization.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the steps of an embodiment of the method for manufacturing a bowling ball according to the present invention, and FIG. 2 is an explanatory diagram showing the conventional manufacturing process.

Claims (1)

[Claims] In a method for manufacturing a bowling ball, which has a two-part structure consisting of a spherical inner core and an outer shell covering the inner core, the inner core has stems attached to opposing positions, and the inner core is suspended in the center of the mold by the stems. fixed,
The method is characterized in that after filling the mold with a skin material and curing it, the mold is taken out from the mold, and the stem protruding from the formed skin is cut out, and the whole is shaped and a finger hole is formed. How to make bowling balls.