JPH0642332B2 - Cal code and method for producing the same - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral so-called curl cord used for electrical connection between a telephone, a handset and other devices and a method for manufacturing the same.

2. Description of the Related Art Generally, when a telephone and a handset are electrically connected to each other, a curl cord that is expandable and contractible in a spiral shape is often used. By the way, this kind of curl code
In each case, as shown in FIG. 6, a plurality of core wires arranged in a straight line in the center of the outer cover is used as the coated conductive wire. Each core wire is covered with a thermoplastic resin having a high rigidity (elastic modulus) such as nylon.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in this type of curl cord that has been conventionally used, the core wire is arranged at the center of the outer skin (that is, a position where a = b in FIG. 6), and the core wire is covered. Since nylon with a high flexural modulus is used for the core wire, the core wire will be broken if the number of times of bending the core wire increases, the rate of change of its own weight will be large, and it will turn over or come apart during use of the curl cord. There was a problem that there were many cases of drooling.

The present invention eliminates the above-mentioned conventional defects, extends the life so that the core wire does not break even when the number of bending times increases, reduces the rate of change of its own weight, and further disperses, twists,
It is intended to provide an excellent curl cord with less entanglement and entanglement.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention individually coats core wires with a thermoplastic resin having a low bending elastic modulus, and arranges the coated core wires in parallel on a straight line. The core wire is arranged as a conducting wire at a position slightly displaced from the center of the soft outer skin of the elliptic approximation shape, and when the coated conducting wire is molded in a spiral shape, the core wire is the center of a circle forming the spiral from the center of the outer skin. It is configured to be on the side closer to.

Action The present invention is configured such that the position of the core wire is offset to the side close to the center of the spiral in this way, and therefore the diameter of the spiral is substantially reduced as a whole, and the spiral, inversion, loosening, and drooping, It has an advantage that twisting, entanglement, and entanglement are significantly reduced.

Embodiment FIG. 1 is a sectional side view of an embodiment of a curl cord according to the present invention. In FIG. 1, reference numeral 1 is a spirally-shaped coated conductor wire, 2a, 2b, 2c and 2d are core wires constituting the covered conductor wire 1, 3a, 3b, 3c and 3d are core wires 2a, 2b and 2c, respectively.
Rigidity (elastic modulus) of polyester etc. that individually coat 2d
Is a coating made of a low thermoplastic resin, and 4 is an outer coat made of soft vinyl chloride or the like provided so as to cover the whole of the coated core wires 2a, 2b, 2c, 2d.

The plurality of core wires 2a, 2b, 2c, 2d are arranged in parallel on a straight line, respectively, and further, their positions are arranged so as to be offset from the center of the outer cover 4 to the side closer to the center of the spiral. .

FIG. 2 is an explanatory view of one manufacturing process for producing the curl cord of the present invention. When producing the curl cord of the present invention, first, the coated conductive wire 1 in which the core wires 2a, 2b, 2c, 2d are arranged at positions slightly deviated from the center of the jacket 4 is used, and this is shown in FIG. As shown, the core wires 2a, 2b, 2c, 2d are spirally wound around the core material 5 so as to come inside. In this case, as the core material 5, a core material having an outer diameter f slightly smaller than the inner diameter e of the curl cord to be finally obtained is used. For example, if the inner diameter e of the curl cord to be finally obtained is 9.6 mm, the outer diameter f as the core material
It is enough to use the one with 7 mm. Then, in this state, the sheathed wire 1 and the sheaths 3a, 3b, 3c,
A temperature (for example, 110 ° C. to 160 ° C.) slightly lower than the melting temperature of the thermoplastic resin forming 3d is applied for a certain period of time (for example, 10 minutes to 30 minutes) and heat treatment is performed. By doing so, the outer skin 4 and the coatings 3a, 3b, 3c, 3d are softened and become a semi-molten state, and in that state, the cooling treatment (cooling condition of 5 to 25 ° C. for about 10 to 30 minutes) is performed next. To do. Then, after that, the core material 5 is removed and a rewinding and reversing process is performed. That is, if the core material 5 is removed by heat treatment and cooling, the coated conductor 1 is tentatively molded into a spiral shape and takes the form of a curl cord. In order to reinforce, the coated conductor 1 that has been wound in the direction of the right-hand thread is in the left-hand thread direction, and the coated conductor 1 that is wound in the left-hand direction is in the right-hand thread direction. Invert. Then, the number of windings is increased by 10 to 20% at the time of reversing so as to eliminate the external disturbance of the curl cord. By doing so, the coated conductive wire 1 wound as shown in FIG. 2 is wound in the opposite direction as shown in FIG. 1, and the contracting force between the coated conductive wires per each rotation is reduced. The curl cord is remarkably improved and has less slack as a whole.

Further, according to the above-described embodiment, the core wire 2 is used as the covered conductor wire 1.
It is assumed that a, 2b, 2c, and 2d are arranged at positions slightly deviated from the center of the outer skin 4 closer to the center of the spiral, so that the diameter of the spiral is considered to be substantially reduced as a whole. , The coated conductor 1 which has been once subjected to the inversion treatment as shown in FIG. 1 is re-inverted again during use as shown in FIG. 2 again, and the occurrence of twisting, entanglement, entanglement, etc. is extremely reduced. Has the advantage. Further, according to the above-mentioned embodiment, there is an advantage that scattering, drooling and the like are remarkably reduced for the same reason, and it is very strong against bending. FIG. 3 and FIG. 4 show this state, which will be described below in more detail with reference to these figures.

First, FIG. 3 forcibly inverts the conventionally known curl cords, the curl cords for comparison, and the curl cords of one embodiment of the present invention, each of which has the structure shown in A, B, and C of the following table ( In the case of one embodiment of the present invention, the condition is returned to that shown in Fig. 2. The conventional product and the comparative product are returned to the same condition).
In this state, how the rate of change in self-weight changes according to the number of days elapsed is measured and graphed. Here, the self-weight change rate represents how much the length of the curl cord increases when it is supported by one end and left hanging. According to this comparison, since the comparative product B is different in shape and material of the outer cover 4 from the conventional product A, the rate of change in self-weight is significantly improved as compared with the curve A as shown by the curve B in FIG. According to the embodiment C of the present invention, the core wires 2a, 2b, 2c, 2d are located closer to the center of the spiral than the center of the outer cover 4, and the diameter of the spiral is substantially reduced. It can be seen that the same effect appears, and as shown by the curve C in FIG. 3, the rate of change of the self-weight length is much smaller than that of the curve B of the comparative product.

Further, FIG. 4 shows the conventional product A which has been conventionally used.
And a graph of the bending test of Example C of the present invention. As is clear from the results, in the conventional product A, as shown in FIG. 4A, when the number of bendings exceeds 150,000, the failure defect rate rapidly increases. In Example B, as shown in FIG. 4C, the failure defect rate hardly occurred even when the number of flexing was 300,000 times. Although not shown, the material of the outer cover was changed to vinyl chloride without polyester, and another bending test was conducted on another embodiment of the present invention having the same configuration as the above-mentioned embodiment C of the present invention. Also in the embodiment, the thickness of both sides of the outer skin 4 bounded by the core wires 2a, 2b, 2c, 2d and the uneven thickness structure make the radius of curvature at bending larger than that of the conventional product A. Third as well as Example C
The characteristics shown in FIG. C were obtained. (0 ° C. in Example C
The characteristics shown in FIG. 3C can be obtained even at the following low temperatures. As described above, according to the embodiments of the present invention, the rate of change in self-weight length is significantly smaller than that of the conventional one, the strength against bending is also increased, and there is less dislocation, sagging, and twisting, entanglement, and entanglement. It has the advantage of being very few.

In addition, in the embodiment, the shape of the outer cover 4 forming the covered conductor 1 is formed into a pan-shaped cross section, but the same effect can be obtained even if the outer cover 4 has a rectangular shape, a circular shape or the like. Further, as shown in FIG. 5, when the cut groove 6 and the like are formed on the side close to the center of the spiral, a further great effect can be expected.

EFFECTS OF THE INVENTION The present invention, as is clear from the above-mentioned embodiment, uses a core wire which is arranged at a position slightly deviated from the center of the outer skin of an elliptic approximation as the coated conductor, and when the core wire is formed into a spiral shape, the core wire is Since it is configured so that it is closer to the center of the circle that forms the spiral than the center of the outer skin, it has the advantage of not breaking even after repeated bending and extending the life, and the rate of change of its own weight is significantly improved and strength is also improved. Strengthen, flip, spill, who,
It has an advantage that an excellent curl cord with very little twist, entanglement, and entanglement can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view of an embodiment of the curl cord of the present invention, FIG. 2 is an explanatory view of one manufacturing process for manufacturing the curl cord of the same embodiment, and FIG. 3 is a conventionally known curl cord. FIG. 4 is a characteristic diagram showing the result of measuring the rate of change in self-weight length of each of the curl cords of the examples of the present invention. FIG. 4 is a characteristic diagram showing the result of the same bending test.
FIG. 6 is a sectional view of a main part of another embodiment, and FIG. 6 is a sectional view of a conventional curl cord. 1 ... Coated conductor, 2a, 2b, 2c, 2d ... Core wire, 3a, 3b, 3
c, 3d …… Coating, 4 …… Outer skin, 5 …… Core material, 6 …… Groove.

 ─────────────────────────────────────────────────── ───Continued from the front page (56) References JP-A-58-189907 (JP, A) Actually opened 50-68287 (JP, U) Actually opened 61-169909 (JP, U) Actually opened 62- 89714 (JP, U)

Claims (2)

[Claims] 1. A core wire is individually coated with a thermoplastic resin having a low flexural modulus, the coated core wires are arranged in parallel on a straight line, and the core wire is covered with a soft outer skin of an elliptic shape. A curl cord arranged at a position slightly deviated from the center so that the core wire is closer to the center of the circle forming the spiral than the center of the outer cover when the coated conductive wire is molded in a spiral shape. 2. A coated conductor wire, in which a core wire is arranged at a position slightly deviated from the center of an outer cover, is used, and the coated conductor wire is used as a core material so that the core wire is on the side close to the center of a circle forming a spiral. It is spirally wound, and in that state, heat is applied to the coated conductor at a temperature slightly lower than the melting temperature of the outer cover, and the outer cover is cooled in a semi-molten state, after which the core material is removed. It is characterized in that the above-mentioned spirally-coated coated wire is reversed to the left-hand thread direction when the spiral direction is the right-hand thread direction, and to the right-hand thread direction when it is the left-hand thread direction. Curling code manufacturing method.