JPH07213659A - Multi-layered lightweight rubber grip and its manufacturing method - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] To manufacture a 10% lighter rubber grip, that is, a lighter rubber grip of 50 g or less per piece. [Structure] Regarding the mandrel, a hole having a diameter of 3 to 5 mm that does not penetrate from one end to the other is opened in the length direction, and a diameter of 0.5 to 5 mm that extends from this hole to the surface of the mandrel.
By providing at least one 1.0 mm hole, preferably 3 to 4 holes, the residual foaming gas generated in the molding of the sponge rubber layer 2 is sucked off by a vacuum pump through the hole in the central portion, A sponge rubber layer 2 is formed by forming a complete rubber sponge layer 2 having no voids or partial defects in the sponge rubber layer 2 due to gas entrapment, and then molding the outside with a fibrous cord and rubber. And the outer rubber layer 3 are joined together to produce a lightweight rubber grip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightweight rubber grip having a multilayer structure and a method for manufacturing the same.

[0002]

2. Description of the Related Art A club that can fly a ball farther away during golf play is a great attraction for golfers, both professionals and amateurs. Although young and physically fit players can use relatively heavy clubs, general golfers are weak, and since everyone's physical strength declines with age, it is preferable to use light clubs rather than heavy clubs. The shaft that composes is also lighter and stronger, from steel to carbon, titanium alloy, etc.
It is changing to a material with a bend.

The head is a portion that hits the ball, and the material, weight, and the like as well as the strength under a certain shape are naturally determined according to the type, application, and the like. On the other hand, the grip is the only point of contact between the club and the golfer, and is an important part that conveys the energy of the person to the club.Because the grip performance such as its shape and feel is determined under certain requirements. is there. Further, the weight of a grip mounted on a club, which is composed of a fixed head and a shaft, has a great influence on the speed of the head when swinging together with the center of gravity of the club.

That is, according to the swing theory of golf, the flight distance of a ball depends on the speed at which the club head swings out, and is determined by the initial velocity at which the ball jumps out. It increases in proportion to the square of the distance from the center of gravity of the club to the grip end. In the case of No. 1 wood (also called a driver) for general men, the head weight is about 200-
250g, shaft weight about 50-60g, grip weight about 55g, the total club weight is about 300-35.
It's like 0g.

The center of gravity of the club is in a proper and proper position for each club depending on its type, use, individual swing form, and the like. Reducing the weight of a grip without changing the shape, feel or other performance of the grip moves the position of its center of gravity towards the head for the same club, i.e. increases the distance from the center of gravity to the end of the grip. It means that it is possible to make a club that improves the flight distance from the above law of motion moment.
This is of great interest to golfers. It can be said that the weight of the grip portion is preferably as light as possible.

For this reason, many attempts have been made to foam rubber to form a sponge, to replace it with a polymer material having a smaller specific gravity, or to use a foam sponge as the inner rubber and a solid two-layer structure as the outer side. However, the grip surface is not satisfactory in terms of abrasion resistance, weather resistance, delicate feel, and other performances.For forming the inner rubber layer into a foam sponge, many foam gases are involved during molding. No finished product could be obtained due to the formation of voids or partial defects, and a light rubber grip of 50 g or less per bottle was not possible.

The present invention has conventionally required performance, that is,
The present invention relates to a method for manufacturing a rubber grip having a slip surface of the grip surface, abrasion resistance, weather resistance, a delicate feel, and the like, which is about 10% lighter, that is, a light rubber grip having a weight of 50 g or less, as shown in FIG. As described above, the purpose of the present invention is to develop a grip having a three-layer structure, in which the inner rubber layer is a foamed sponge, and the outer side is a conventional fiber cord and a rubber layer.

[Means for Solving the Problems]

As a result of earnest studies, the present inventors have found that the mandrel used in the manufacturing method described in detail below is
As shown in FIG. 2, a hole having a diameter of 3 to 5 mm is opened in the length direction from the end on the side communicating with the outside to the vicinity of the tip, and a diameter of 0.5 to 1.0 m communicating from the hole to the surface of the mandrel.
By providing at least one hole, preferably three to four holes of m, the residual foaming gas generated in the molding of the sponge rubber layer is sucked by a vacuum pump through the hole in the central portion and removed, and the inside sponge rubber layer is removed. After forming a complete sponge rubber layer that does not have voids or partial defects due to inclusion of foaming gas in molding, the outer side is sponge rubber layer and outer rubber layer by molding the outside with fibrous cord and rubber. It is also possible to manufacture a lightweight rubber grip that is completely joined to. Further, the outer rubber layer is manufactured by a conventional method using a rubber material with a cord to produce a light rubber grip having the required performance.

That is, as shown in FIG. 5, after the set of mold and mandrel used is heated to 150 ° C.,
Put a predetermined amount of rubber cloth based on sponge rubber in a predetermined gauge into the lower mold, set the above mandrel on it, and then place the same amount of the same sponge rubber cloth on the mandrel, Heat through the mold at 150 ° C. for 5 minutes under pressure. During this time, the gas generated inside the mold during pressurization and heating is removed from the hole at the end communicating with the outside of the mandrel by a vacuum pump at appropriate times.

After molding the sponge rubber portion in this way, a rubber mold with a design for the outside is used as shown in FIG. After setting the sponge rubber part molded in advance together with the mandrel as described above, similarly, a rubber material with a cord is placed on the sponge rubber part and heated under pressure at 150 ° C. for 5 minutes through the upper mold. As described above, a lightweight rubber grip having a three-layer structure including a rubber sponge inside and a cord-containing rubber outside can be manufactured.

【The invention's effect】

As shown in FIG. 2, the mandrel used for molding the rubber grip is provided with a hole from the end on the side communicating with the outside in the length direction thereof, and a hole communicating with the surface of the mandrel is provided from this hole. , The residual foaming gas generated during the molding of the sponge rubber layer is sucked from the end communicating with the outside of the mandrel with the vacuum hole through the hole in the center and wiped off. After forming a complete rubber sponge layer with no cavities or partial defects, by molding the outside with fibrous cord and rubber, the sponge rubber layer and the outer rubber layer are also completely joined, The rubber layer was able to produce a light rubber grip with conventional performance.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a rubber grip having a three-layer structure according to the present invention.

2 is an enlarged cross-sectional view of a rubber grip taken along the line AA of FIG.

FIG. 3 is a perspective view of a mandrel used for manufacturing a rubber grip according to the present invention.

4 is a cross-sectional view of the mandrel in FIG. 3 in the longitudinal direction.

FIG. 5 is a sectional view showing an outline of molding of a rubber sponge portion according to the present invention.

FIG. 6 is a sectional view showing an outline of molding of a rubber grip having a three-layer structure according to the present invention.

[Explanation of symbols]

 1 Code Layer 2 Sponge Rubber Layer 3 Rubber Layer 4 Mandrel Main Body 5 Hole with Diameter 0.5 to 1.0 mm 6 Hole with Diameter 3 to 5 mm 7 Upper Mold for Sponge Rubber Layer Molding 8 Lower Mold for Sponge Rubber Layer Molding 9 Mandrel tip support 10 Rubber fabric for sponge rubber molding 11 Upper mold for outer design molding 12 Lower mold for outer design molding 13 Mandrel tip support 14 Rubber cloth with cord 15 Sponge rubber 16 Holes leading to outside of mandrel

Claims (1)

[Claims] 1. A method for producing a rubber grip having a multi-layer structure in which a pore is provided in a central portion of a mandrel and a gas generated inside through the pore is removed by suction.