JPS63218104A - Curl cord and its manufacturing method - 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 Field of the Invention The present invention relates to a spiral so-called curl cord used for electrical connection between telephones, computers and other equipment, and a method for manufacturing the same.

2. Description of the Related Art In general, when electrically connecting a telephone and a handset to each other, an extensible curl cord formed into a spiral shape is often used. By the way, all curl cords of this kind that have been used in the past use a ζ-coated conducting wire in which a plurality of core wires are arranged in a straight line in the center of the outer sheath, as shown in FIG. Each core wire is coated with a thermoplastic resin having a high modulus of rigidity (modulus of elasticity) such as polyester or nylon, and a soft vinyl chloride resin or the like is often used for the outer skin.

Problems to be Solved by the Invention However, in this type of curl cord that has been conventionally used, the core wire is located at the center of the outer shell (i.e., at the position where a=bζ in FIG. 6), and during use, The present invention eliminates the above-mentioned drawbacks of the conventional technology, and has a simple structure that prevents the occurrence of reversal, unraveling, and drooping. , twist, entanglement,
The purpose is to provide an excellent curl cord with less tangles.

Means for Solving the Problems In order to achieve the above object, the present invention uses a coated conductor in which the core wire is positioned slightly away from the center of the outer sheath, and the coated conductor is formed into a spiral shape. In this state, the core wire is configured to shift from the center of the outer skin to a side closer to the center of the circle constituting the spiral.

Function The present invention is configured such that the position of the core wire is shifted to the side closer to the center of the spiral, and therefore the diameter of the spiral as a whole becomes substantially smaller, preventing inversion, unraveling, It has the advantage that droop, twisting, tangling, tangles, etc. are significantly reduced.

Embodiment FIG. 1 is a sectional side view of an embodiment of the curl cord of the present invention. In FIG. 1, 1 is a spirally molded coated conductor; 2a, 2b, 2C, and 2d are core wires constituting the coated conductor 1; 3a + 3b y 3
c+3d are core wires 2a, 2b, 2c, respectively
, 2d are individually covered with a coating made of a thermoplastic resin having a high rigidity (modulus of elasticity) such as polyester, nylon, polypropylene, polyethylene, etc., and 4 is a coating made of a thermoplastic resin having a high modulus of rigidity (modulus of elasticity) such as polyester, nylon, polypropylene, polyethylene, etc., and 4 is a coating made of a thermoplastic resin that covers the entire coated core wires 2a, 2b, 2c, and 2a. This is an outer skin made of soft vinyl chloride, etc.

In addition, a plurality of core wires 2a, 2b, 2c, 2d
are arranged in parallel on a straight line, and
It is arranged so that its position is closer to the center of the spiral than the center of the outer skin 4.

FIG. 2 is an explanatory diagram of one manufacturing process for producing the curled cord of the present invention. When producing the curled cord of the present invention, first, the core wires 2a and 2b are produced.

A coated conductor 1 is used in which wires 2C and 2d are placed at positions slightly offset from the center of the jacket 4, and the core wire 5 is placed so that the core wires 2a, 2b, 2c, and 2d are on the inside as shown in FIG. Wrap it in a spiral. In this case, the core material 5 used is a core material having an outer diameter f that is slightly smaller than the inner diameter e of the curled cord that is desired to be finally obtained. For example, if the inner diameter e of the final ζ curl cord is 9.6 mm, the outer diameter f of the core material is 7 mm.
You can use one.

In this state, the spirally wound coated conductor 1 is heated to a temperature slightly lower than the melting temperature of the thermoplastic resin (for example, 110°C
~160° C.) for a certain period of time (for example, 10 minutes to 30 minutes) for heat treatment. In this way, the outer cover 4 and the cover fi3
Since a, 3b, 3c, and 3d are softened and become a semi-molten state, a cooling treatment (cooling condition: 5 to 25° C. for about 10 to 30 minutes) is performed next. After that, the core material 5 is removed and unwinding and reversing processing is performed. That is, if the core material 5 is removed by heat treatment and cooling treatment, the coated conductive wire 1 will be formed into a spiral shape and take the form of a curl cord, but if left as it is, the contraction force of the curl cord will not be very strong (
- Therefore, in order to strengthen this, if the covered conductor 1 was wound in the direction of right-hand thread, then it should be wound in the direction of left-hand thread. Each is reversed in the direction of the right-hand thread.Then, at the time of reversal, the number of windings is increased by 10 to 20% to eliminate external disturbance of the curl cord.

In this way, the coated conductor 1 wound as shown in Figure 2 is wound in the opposite direction as shown in Figure 1, and the contraction force between the coated conductors per rotation is This results in a marked improvement in the curling of the cord, resulting in a curled cord with less sagging as a whole.

According to the above embodiment, the core wire 2 is used as the covered conductor 1.
A, 2b, 2c, and 2d are arranged at slightly shifted positions closer to the center of the spiral than the center of the outer skin 4, and therefore, the diameter of the spiral as a whole seems to be substantially smaller. As shown in FIG. 2, the coated conductor wire 1 that has been subjected to the reverse treatment as shown in FIG. It has the advantage of being less. Further, according to the above-mentioned embodiment, for the same reason, there is a significant reduction in the amount of unraveling and drooping, and there is an advantage that it is extremely strong against bending. FIGS. 3 and 4 show this state, and a more detailed explanation will be given below based on these figures.

First, Figure 3 shows A, 13. in the table below. The conventionally known curl code, the comparative curl code, and the curl code of an embodiment of the present invention each configured as shown in FIG. Return to condition. Conventional product.

The comparison product was also returned to the same state), and in that state, how the dead weight length change rate changed depending on the number of days that had passed was measured and graphed. Here, the dead weight length change rate represents how much the length of the curled cord increases when it is supported at one end and left hanging. and,
According to this comparison, the shape and material of the outer skin 4 of comparative product B are different from those of conventional product A, and as a result, as shown in curve B in Fig. 3, the rate of change in dead weight length was improved to a greater extent than curve A. However, according to Example C of the present invention, the core wire 2
When a + 2 b +' 2 c, 2 d are located closer to the center of the spiral than the center of the outer skin 4, and the diameter of the spiral becomes substantially smaller, the same effect appears, as shown in curve C in Figure 3. It can be seen that the dead weight length change rate is much smaller than curve B of the comparative product.

Further, FIG. 4 is a graph of the results of bending tests and tests performed on the conventional product A, which has been used in the past, and the above-mentioned Example C of the present invention. As is clear from the results, as shown in FIG. 4A, the failure rate of conventional product A suddenly increases when the number of bends exceeds 150,000 times, whereas In Example C, as shown in Figure 4, almost no failure rate occurred even after 300,000 bends. Although not shown, a bending test was similarly conducted on another embodiment of the present invention, which was constructed in the same manner as the above-mentioned embodiment C, except that the material of the outer skin was changed to vinyl chloride without polyester. In this embodiment, the radius of curvature when bent is larger than that of the conventional product A due to the wall thickness and uneven thickness structure on both sides of the outer skin 40 bordering on the core wires 2a, 2b, and 2C92d. Similar to the above, characteristics as shown in Figure 3 were obtained. (Example C
In this case, the characteristics shown in Figure 3 can be obtained even at low temperatures below 0°C. ) As described above, according to an embodiment of the present invention, the rate of change in dead weight length is significantly smaller than that of the conventional one, the strength against bending is stronger, and there is less chance of unraveling, sagging, etc. This has the advantage of reducing the number of emergency calls.

In the embodiment, the shape of the outer sheath 4 constituting the covered conductive wire 1 is shaped like a sweet bean paste in cross section, but the same effect can be obtained even if the shape of the outer sheath 4 is rectangular, circular, or other shape. Further, as shown in FIG. 5, an even greater effect can be expected when the kerf 6 or the like is formed on the side closer to the center of the spiral.

Effects of the Invention As is clear from the above embodiments, the present invention uses a coated conductor wire in which the core wire is placed at a position slightly shifted from the center of the outer sheath, and the coated conductor wire is formed into a spiral shape so that the core wire is It is configured so that it is shifted from the center of the outer skin to the side closer to the center of the spiral. Therefore, according to the present invention, the rate of change in dead weight length is significantly improved, the strength is increased, and there is no possibility of inversion, unraveling, sagging, etc. It has the advantage of being able to obtain an excellent curled cord with very few twists, tangles, entanglements, etc.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional side view of one embodiment of the curl cord of the present invention, Fig. 2 is an explanatory diagram of one manufacturing process for manufacturing the curl cord of the same embodiment, and Fig. 3 is a conventionally known curl cord. Figure 4 is a characteristic diagram showing the results of measuring the rate of change in dead weight length of the cord and the curled cord of the above-mentioned embodiment of the present invention, and Figure 4 is a characteristic diagram showing the results of a similar bending test.
The figure is a sectional view of a main part of another embodiment. FIG. 6 is a sectional view of a conventional curl cord. 1... Covered conductive wire, 2a, 2b, 2c, 2d1. , core wire, 3;]. 3b, 3c, 3a... Covering, 4. Outer skin, 5. Core wire, 6
...kerf. Name of agent: Patent attorney Toshio Nakao and 1 other famous quote
1 Fig. 2 Fig. 3 Fig. 4 Examination 8 urinary malt (V times p) 2. Name of the invention Curl cord and its manufacturing method - 3. Relationship with the amended case Patent application Address 1006 Kadoma, Kadoma City, Osaka Name
(582) Matsushita Electric Industrial Co., Ltd. Address: Matsushita Electric Industrial Co., Ltd., 1006 Kadoma, Monsu City, Osaka Prefecture [Contact phone: (Tokyo) 437-1121 Kurakyo Legal Affairs Branch]
""-"6 Subject of amendment 6, Contents of amendment (1) The scope of claims column of the specification will be corrected as shown in the attached sheet. (2) Page 3 of the specification, line 7, line 8, Correct "core wire" in line 15, page 4, line 6, line 8, and line 12 of the same page to "core wire." (3) "Figure 4 C" in the 6th line from the bottom of page 9 is corrected to "Figure 4 B." (4) Correct "core wire" in the second line of page 12 to "heartwood." 2. Scope of Claims (1) When a coated conductor wire is used in which the core wire is placed at a position slightly shifted from the center of the outer sheath, and when this coated conductor wire is formed into a spiral shape, the core wire is located at a position slightly offset from the center of the outer sheath. Curl cord configured as shown in the example near the center of the spiral above. (2) The core wires are individually made of polyester, nylon,
The curl cord according to claim 1, which is coated with a thermoplastic resin having a high modulus of rigidity (modulus of elasticity) such as polypropylene or polyethylene, and is arranged in parallel on a straight line. (3) The curl cord according to claim 1 or 2, wherein the outer skin is made of a soft thermoplastic resin such as vinyl chloride. (4) The curl cord according to claim 1 or 2, wherein the outer sheath is made of polyester-containing vinyl chloride/L/. (5) A cut groove is formed on the outer surface of the outer skin on the side closer to the center of the spiral.
戊's curl code. (6) Use a coated conductor whose core wire is placed slightly away from the center of the outer sheath, and wind the coated conductor in a spiral around the core material so that the core wire is close to the center of the spiral. Heat is applied to the coated conductive wire at a temperature slightly lower than the melting temperature of the sheath, and the sheath is cooled in a semi-molten state, and then the core is removed to form the helical sheath. A method for manufacturing a curl cord, characterized in that the width of the conductive wire is reversed in the direction of the left-hand thread if the direction of the spiral is a right-hand thread, and in the direction of the right-hand thread if the direction of the spiral is a left-hand thread.

Claims (6)

[Claims] (1) Use a coated conductor whose core wire is placed at a position slightly offset from the center of the outer sheath, and when this coated conductor is formed into a spiral shape, the core wire is closer to the center of the spiral than the center of the sheath. Curl code configured as in the example. (2) The core wires are individually made of polyester, nylon,
The curl cord according to claim 1, which is coated with a thermoplastic resin having a high modulus of rigidity (modulus of elasticity) such as polypropylene or polyethylene, and is arranged in parallel in a straight line. (3) The curl cord according to claim 1 or 2, wherein the outer skin is made of a soft thermoplastic resin such as vinyl chloride. (4) The curl cord according to claim 1 or 2, wherein the outer skin is made of vinyl chloride containing polyester. (5) The curl cord according to claim 1, wherein a cut groove is formed on the outer surface of the outer skin on the side closer to the center of the spiral. (6) Use a coated conductor in which the core wire is placed at a position slightly offset from the center of the outer sheath, and wind the coated conductor in a spiral around the core wire so that the core wire is close to the center of the spiral. Heat is applied to the covered conductor wire at a temperature slightly lower than the melting temperature of the outer sheath, and the outer sheath is cooled in a semi-molten state, and then the core material is removed to form the spiral shape. A method for manufacturing a curl cord, characterized in that the helical direction of the coated conductor is reversed so that if the helical direction is a right-handed thread, it becomes a left-handed thread, and if the spiral direction is a left-handed thread, the spiral direction is reversed so that it becomes a right-handed thread.