JPH0347346B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to a core string made of chemical fibers or natural fibers made of thermoplastic synthetic resin material, or a blend thereof, and a ball made of thermoplastic synthetic resin material as appropriate. This invention relates to an endless synthetic resin ball chain fixed at intervals.

BACKGROUND TECHNOLOGY Conventionally, balls are fixed to a single core string at appropriate intervals, the ends of this string are joined to form an endless loop, and the balls are injection molded onto the joints of the core string. The joint part is hidden by the ball and looks good,
Further, an endless synthetic resin ball chain in which the connection strength of the joint portion is increased is disclosed in Japanese Utility Model Application Publication No. 181391/1983.

Problems to be Solved by the Invention However, when this endless synthetic resin ball chain is used in areas where large tensions are applied, such as operating strings for raising and lowering large blinds, there are still concerns about the tensile strength. There was a problem.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an endless synthetic resin ball chain that can withstand large tensile forces and is difficult to break at joints. .

Means for Solving the Problems According to the present invention, the above problems can be solved by fixing a plurality of balls made of thermoplastic synthetic resin material at appropriate equal pitches to a core string formed by bundling a plurality of strings. , one end and the other end of each of the strings are joined by shifting each other by a length corresponding to one pitch of the ball to form an endless shape, and the position of each joint is covered with the core string. This problem can be solved by fixing a joining ball made of a synthetic resin material.

Embodiments Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

FIG. 1 shows the state of the endless synthetic resin ball chain according to the present invention before joining. In FIG. 1, 1 is a chemical fiber made of thermoplastic synthetic resin material such as polyamide or polyester. The core cord is formed by bundling together a plurality of cords 2, 3, and 4 of appropriate length (three in the illustrated example) made of twisted yarn spun. The material of the strings 2, 3, and 4 is not limited to chemical fibers, but may be natural fibers or a blend of chemical fibers and natural fibers.

A plurality of balls 5 are fixed in advance to the core string 1 at appropriate equal pitches, and one of the first string 2, second string 3, and third string 4 that constitute the core string 1 is fixed to the core string 1 in advance. ends 2a, 3a, 4a and the other end 2b, 3
b and 4b are cut to different lengths.
Note that the pitch refers to the distance from the center of the ball 5 of the core string 1 to the center of the adjacent ball 5.

In the core string 1, one end 2a of the first string 2 is cut to a length corresponding to one pitch of the ball 5, and the other end 2b is cut to a length corresponding to three pitches of the ball 5. In addition, one end 3a of the second string 3 is cut to a length corresponding to two pitches of the ball 5, and the other end 3b is cut to a length corresponding to three pitches of the ball 5, and One end 4a of the third string 4 is cut to a length corresponding to three pitches of the ball 5, and the other end 4b is cut to a length corresponding to one pitch of the ball 5.

FIG. 2 shows a state in which the core string 1 is joined in an endless manner, with one end 2a and the other end 2b of the first string 2, and one end 3a of the second string 3. and the other end 3b, and the one end 4a and the other end 4b of the third string 4 are abutted against each other, and the respective strings 2 are attached using an ultrasonic welder or other heat-sealing device (not shown), adhesive, or the like. , 3, 4 with joints 6, 7,
8 is formed, and the core string 1 is joined in an endless manner by these joint parts 6, 7, and 8.

The joint parts 6, 7, 8 are each shifted by a length corresponding to one pitch of the ball 5 and are spaced apart from each other at different positions so as not to overlap with each other. As shown in FIG. 3, a joining ball 9 having the same shape and size as the ball 5 is fixed.

The ball 5 and the joining ball 9 are made of a thermoplastic synthetic resin material such as polyacetal or polyamide, and the core string 1 is held between an upper mold and a lower mold of a synthetic resin injection molding machine (not shown), and It is fixed to the core string 1 by injecting the synthetic resin material into a spherical fused portion cut into the mold and the lower mold. In the illustrated example, both balls 5 and 9 are formed into elliptical spheres and have the same shape and size, but they are not limited to this shape and size.

FIG. 4 shows joining balls 9 that cover and adhere to the core string 1 at the respective joint portions 6, 7, and 8 of the core string 1.
, each joining ball 9 is connected to a string 2,
The joints 6, 7, 8 of 3, 4 are located approximately in the center of the ball 9 in the lateral direction [the longitudinal direction of the core string 1], and the strings 2, 3, 4 are located in the longitudinal direction of the ball 9 [the strings 2, 3 ,4
The core cord 1 is injection-molded in a bundle at approximately the center in the radial direction of the core cord 1. Note that each ball 5 that has been fixed in advance to the core string 1 is injection molded onto the core string 1 by converging the strings 2, 3, and 4 approximately at the longitudinal center of the ball 5, as shown in FIG. ing.

In the endless synthetic resin ball chain of the present invention having such a structure, one ball chain of a predetermined length is first formed, and then both ends are connected in an endless manner. In this situation, the length of the ball chain itself can be adjusted by increasing or decreasing the number of balls 5 fixed to the core string 1 in advance, and the length of the ball chain itself can be adjusted by increasing or decreasing the number of balls 5 fixed to the core string 1. are formed by the strings 2, 3, and 4, and the joint portions 6, 7, and 8 are formed at mutually different and shifted positions, so that when the joining ball 9 is attached to the core string 1 by injection molding, it is injected. In a state where the molten synthetic resin material surrounds the front and rear outer peripheries of the joint parts 6, 7, and 8, a part of the molten synthetic resin material penetrates into the fiber structure of the core string 1 itself and solidifies. The joining balls 9 are firmly bonded and fixed to the core string 1 and become integrated, thereby increasing the tensile strength.

In the above-mentioned embodiment, the core string 1 was formed by three strings 2, 3, and 4, and the joining balls 9 were fixed to the respective joints 6, 7, and 8 of the core string 1. Although an example has been shown, as shown in FIG. You may. In this case, one end 2a of the first string 2 constituting the core string 1 is cut to a length corresponding to one pitch of the ball 5 fixed to the core string 1 in advance, and the other end 2a
b is cut to a length equal to two pitches of the ball 5, one end 3a of the second string 3 is cut to a length equal to two pitches of the ball 5, and the other end 3b is cut to a length equal to two pitches of the ball 5. is cut into a length corresponding to one pitch of the ball 5. Then, the respective joint portions 6 and 7 of the core string 1
are spaced apart from each other by a length corresponding to one pitch of the ball 5.

Furthermore, the strings 2, 3, and 4 used in the core string 1 do not necessarily have to be twisted yarns, and may be, for example, knitted strings or monofilament strings.

Effects of the Invention As described above, in the present invention, a plurality of balls made of a thermoplastic synthetic resin material are fixed to a core string formed by bundling a plurality of strings at appropriate equal pitches, and one of the strings is fixed to a core string formed by bundling a plurality of strings. A joining ball made of a synthetic resin material, in which one end and the other end are joined by shifting each other by a length corresponding to one pitch of the ball to form an endless shape, and the core string is covered at the position of each joining part. Since this is an endless synthetic resin ball chain made of a ball chain fixed to the core string, even when a large tensile force is applied, each ball is The tensile force applied between the core strings is dispersed and reduced by the plurality of core strings, and therefore the strength of the core string itself can be increased. Further, since there are a plurality of core strings and a joining ball is fixed to each joining part, there is an advantage that the joining strength of that part is increased and it is difficult to break.
Furthermore, since one ball chain of a predetermined length is first formed and then both ends are connected endlessly,
In the state before the core strings are joined, there is an advantage that the length of the ball chain itself can be freely adjusted by increasing or decreasing the number of balls fixed to the core strings in advance.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the endless synthetic resin ball chain according to the present invention in a state before joining, FIG. 2 is a plan view showing the endless synthetic resin ball chain in a joined state, and FIG. 4 is an enlarged perspective view of the portion shown in FIG. 3; FIG. 5 is a perspective view showing a completed product of an endless synthetic resin ball chain;
The figure is a partially enlarged plan view showing another embodiment of the endless synthetic resin ball chain. 1: Core string, 2, 3, 4: String, 5: Ball, 6,
7, 8: joint part, 9: joint ball.

Claims (1)

[Claims] 1 A ball 5 made of a thermoplastic synthetic resin material is attached to a core string 1 formed by bundling a plurality of strings 2, 3, and 4.
A plurality of strings are fixed at appropriate equal pitches, and one end 2a, 3a, 4a and the other end 2b, 3b, 4b of each of the strings 2, 3, 4 correspond to one pitch of the ball 5. It is characterized in that it is made into an endless shape by being joined at different lengths, and joining balls 9 made of a synthetic resin material covering the core string 1 are fixed at the positions of the respective joining parts 6, 7, and 8. Endless synthetic resin ball chain.