JPH0123221B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape longitudinal application device, and mainly to a tape longitudinal application device suitable for performing tape longitudinal application in cable manufacturing.

Cable manufacturing may involve a step of vertically wrapping a metal tape around the cable insulating layer for the purpose of imparting a water-shielding function. In such a process, the tape is fed in the longitudinal direction as the cable core moves, and both are passed through a tape longitudinal attachment device equipped with a forming die that matches the outer shape of the cable core. It is common practice to apply the tape vertically around the cable core so that both edges overlap, and at the same time deform the tape to match the outer shape of the cable core.

FIG. 1 shows a cross section of an example of a forming die used in a conventional tape longitudinal application device of this type. In FIG. 1, the die 1 is simply a cylindrical rigid body, the inner diameter of which matches the maximum tolerance Dmax of the outer diameter of the cable core 3. Therefore,
In the vicinity where the outer diameter of the cable core 3 is the maximum, the cable core 3 and the tape 2 are almost vertically attached, but when the outer diameter of the cable core 3 is around the minimum value Dmin, the cable core 3 and the tape 2 are attached vertically. The tapes are attached vertically with a gap between them, and in a later step, a sheath is extruded and coated on two circumferences of the tape using an extruder. In such a case, if the tape 2 is made of a relatively elastic material such as aluminum, the tape will be in close contact with the outer periphery of the cable core due to the compressive force exerted by the provision of the sheath. However, if the cable is made of a material with low elasticity, such as lead, this compressive force causes partial deformation, which not only spoils the appearance of the finished cable, but also causes the tape to lose its characteristics. For this reason, when a conventional tape longitudinal application device is used, an additional step is required to finish the tape so that it matches the cable core diameter immediately before applying the sheath.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a tape longitudinal spreading apparatus that can overcome the drawbacks associated with conventional tape longitudinal spreading apparatuses.

According to the present invention, the above object is achieved by making the inner diameter of the tape longitudinal application device flexible.

Hereinafter, one embodiment of the present invention will be described in detail based on FIGS. 2 to 4.

FIG. 2 is a schematic diagram showing the main part of a portion in which a plurality of thin rods are configured into a tapered drum shape.

In FIG. 2, a plurality of thin metal rods 5 have one ends fixed to a metal ring 4 at equal intervals by welding. More specifically, each thin metal rod 5 is arranged with its other end facing inward of the metal ring 4 and at the same time being inclined at appropriate angles θ ₁ and θ ₂ toward the circumferential direction, so that the entire metal rod has a tapered drum shape. The thin rods 5 are configured to provide an opening with a reduced diameter near the rear end. Figure 3 is the second
FIG. The straight line φD of this opening is selected in advance to be equal to the minimum diameter of the cable, and the thin rod 5
Allows itself to bend so that φD can reach its maximum diameter.

By arranging the plurality of thin metal rods 5 in a drum shape in this way, the passage of the metal tape through this portion becomes extremely smooth, and the tightening force of the thin metal rods 5 against the metal tape increases continuously. Therefore, the metal tape can be formed into an ideal shape.

FIG. 4 is a schematic cross-sectional view of a tape longitudinal application device in which a plurality of thin metal rods providing such an adjustable inner diameter are provided at the tape exit side end of a forming die. In FIG. 4, a presser ring 11 is arranged on the outer periphery of the tape exit side end of the forming die 1, which may be a conventional one, and a semicircular shape is placed on the inner periphery of the presser ring 11 and the outer periphery of the tape exit side end of the forming die 1. A groove 12 is provided, the metal ring 4 is placed in the groove having a circular cross section, and a plurality of thin metal rods 5 shown in FIG.
It is formed so as to protrude toward the rear. Note that metals are usually used as the material for the forming die 1 and the presser ring 11, but the material is of course not limited to this, as long as it has a predetermined mechanical strength. Other examples include, for example, hard plastics.
The same applies to the material of the thin rod 5. Further, the entire presser ring 11 is divided into two halves in the axial direction, and is configured to be detachably attached to the forming die 1.

When the lead tape 2 for longitudinal attachment is introduced into the tape longitudinal attachment device configured in this way in parallel with the cable core 3 whose outer diameter changes, the tape 2 first passes through the forming die 1 at the entrance. Therefore, it is sequentially rolled in the longitudinal direction so that both ends are overlapped, and after being sequentially covered longitudinally on the circumference of the cable core 3, it is tightly attached to the outer circumference of the cable core 3 by the thin rod 5. In this way, the tape diameter matching the diameter of the cable core 3 is automatically obtained, and a fully satisfactory longitudinal application of the tape can be achieved.

In the embodiment described above, the thin rod is cantilever-supported by a metal ring at the end of the tape exit side of the forming die, but a ring capable of reducing the diameter is also provided at the rear end. The inner diameter near the rear end can also be made variable by rotating the section.

According to the tape longitudinal attachment device of the present invention, the longitudinally attached tape is constantly pressed onto the core circumference of the cable wire by a forming die, and then the cable is Because it is further tightened by following the change in the outer diameter of the wire core,
Adhesion of the tape to the outer surface of the cable core is sufficiently improved.

Therefore, the separate process for shaping the longitudinally attached tape, which was conventionally required, can be omitted, which is extremely advantageous in cable manufacturing.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a forming die used in a conventional tape longitudinal application device, and Fig. 2 is a schematic diagram of the main parts of a plurality of thin rods used in the tape longitudinal application device of the present invention. 3 is a side view taken at - in FIG. 2, and FIG. 4 is a sectional view schematically showing the tape longitudinal application device of the present invention. 1: Forming die, 2: Lead tape, 3:
Cable core, 4: Metal ring, 5: Metal thin rod,
11: Presser ring.

Claims (1)

[Claims] 1. Roll up a tape running along with a filament such as a cable running in the longitudinal direction in the longitudinal direction until both ends abut or overlap,
It consists of a forming die 1 having a guide hole for longitudinally supporting the tape on the periphery of the filament, and a plurality of thin rods 5 provided rearward from the tape exit end of the forming die 1. , the plurality of thin rods 5 are evenly distributed in the circumferential direction of the forming die 1, and each thin rod 5 is arranged so as to face inward of the forming die 1 and at the same time be inclined toward the circumferential direction. , a tape longitudinal attachment device characterized in that the entire tape is configured in a tapered drum shape.