JPS601452Y2 - Seal cap for coaxial cable core extrusion coating - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sealing cap for extruding a coaxial cable core with a Cordel cord.

For example, in a leaky coaxial cable, a Cordel cord is wound around a center conductor, and an outer conductor is coated around the outer circumference of the Cordel cord.

Since the outer conductor is very thin, there is a risk that it will fall between the winding pitches of the Cordell string and be deformed.

Such deformation of the outer conductor is undesirable in terms of the characteristics and appearance of the coaxial cable.

In order to prevent the above-mentioned deformation of the outer conductor, a coaxial cable core is coated with an extruded plastic tube in contact with the outer periphery of the Cordel cord, and the outer conductor is coated on top of the extruded plastic tube.

To form the above tube, air is blown from the core inlet side of the extruder while extrusion coating is carried out while preventing deformation of the molten resin, and then a sizing process is performed to determine the outer shape of the tube.
Adjust the dimensions.

A die is installed inside the extruder to seal the outer periphery of the wire core to prevent air leakage, but the seal of the conventional die is not sufficient and air leaks from the core inlet side.
There was a risk that it would not reach the tip of the nipple.

The present invention was developed based on the above-mentioned circumstances, and provides a sealing cap that can provide almost complete sealing when extrusion coating is applied to a coaxial cable core with a Cordel cord.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

In the drawing, a pair of sealing members 3 are spaced apart in the axial direction and are concentrically and rotatably arranged in a cylindrical cap holder 2 screwed onto the wire center entry end of a commonly used nipple holder 1. It is set in.

The sealing members 3 are supported by bearings 4, and spacers 5 are inserted between the bearings 4 to define the spacing between the sealing members 3.

Note that the sealing member 3 is fixed by a retaining tube 6 screwed onto the end of the holder 2.

Further, the seal member 3 has the following structure.

That is, the through hole 7 has a diameter approximately equal to the outer diameter of the central conductor of the wire core.
The inner circumferential surface of the through hole 7 is provided with a groove 8 having a cross-sectional shape almost equal to the cross-sectional shape of the Cordell string, and forming a part of a spiral similar to the spiral wound around the Cordell string. .

To perform extrusion coating with the sealing cap of the present invention having the above configuration, the cordel cord of the wire core is engaged with the groove 8 of the sealing member 3, and the wire core is run, from a position on the nipple exit side of the sealing cap. Extrusion coating is carried out in a conventional manner while blowing air into the nipple.

As the wire core travels, the sealing member rotates due to the engagement of the groove 8 and the Cordel cord, thereby receiving a circumferential force.

In the seal cap of the present invention, the center conductor of the wire core is sealed by the through hole 7 of the sealing member, and the Cordel cord wrapped around it is sealed by the groove 8, so that air does not enter the wire core inlet side. There is almost no leakage, the tube reaches the tip of the nipple, the air pressure inside the extrusion coated tube is never insufficient, and a well-shaped tube is formed.

Note that the present invention is not limited to the above embodiments.

For example, the number of seal members is not limited to one pair.

[Brief explanation of the drawing]

The figure is a sectional view of an embodiment of the present invention. 2...Cap holder, 3...Sealing member, 4...Bearing, 5...Spacer, 6...
... Stop tube, 7 ... Through hole, 8 ...
·groove.

Claims (1)

[Scope of Claim for Utility Model Registration] ■ A cylindrical cap holder attached to the core entrance side of the nipple, and a cylindrical cap holder that is concentrically and rotatably supported within this cap holder and that is approximately on the outside diameter of the center conductor of the wire core. A coaxial cable core extrusion covering comprising a through hole of the same diameter and a sealing member having a groove on the peripheral wall of the through hole that is a part of a spiral formed by the Cordel string and has a cross section that is approximately equal to the cross section of the Cordel string. Seal base. (2) The coaxial cable core extrusion coated metal seal cap according to claim 1, wherein the sealing member has a plurality of cylinders distributed in the axial direction of the cap holder.