Cable jacket extrusion mold, cable manufacturing method, and optical cable manufactured thereby

Abstract

The present invention relates to a cable jacket extrusion mold, a cable manufacturing method, and an optical cable manufactured thereby, the mold allowing, during the extrusion process, a ripcord for stripping a cable jacket to be stably accommodated in a notch region formed on the inner circumferential surface of the cable jacket.

Description

Cable jacket extrusion mold, cable manufacturing method, and optical cable manufactured thereby

[0001] The present invention relates to a cable jacket extrusion mold, a cable manufacturing method, and an optical cable manufactured thereby. More specifically, the present invention relates to a cable jacket extrusion mold capable of stably receiving a rip cord for cable jacket stripping in a notch area formed on the inner surface of the cable jacket during the cable jacket extrusion process, a cable manufacturing method, and an optical cable manufactured thereby.

[0002] With the recent rise in demand for ultra-high-speed communications, demand for optical cable-based communications networks is also steadily increasing. Compared to conventional copper cables, optical cables offer greater bandwidth and are lighter and more compact, making them advantageous for building ultra-high-speed transmission networks.

[0003] The structure of the optical cable may include, as an example, a cable core in which a plurality of optical units are assembled, a cable jacket wrapping the cable core, and at least one rip cord disposed on the inner surface of the cable jacket for stripping the cable jacket.

[0004] Meanwhile, in order to improve workability during stripping of the cable jacket, the optical cable may have at least one notch formed outwardly along the length of the inner surface of the cable jacket, and in this case, the rip cord may be placed in the inner space of each notch.

[0005] In order to cover the cable jacket with the ripcord placed on the inner surface of the jacket, the optical cable core and the ripcord on the outer surface are put into the extrusion mold together and the cable jacket is extruded.

[0006] However, during the process of wrapping and covering the outer surface of the core with the highly viscous extrudate in a molten state, the fiber bundle-shaped ripcord may be pushed out and its position may be changed, so that it may not be covered within the originally intended notch and may be displaced. Alternatively, after the extrudate is cooled, the ripcord placed within the notch may move to an unintended position and be displaced due to the clearance between the core and the jacket. This will be examined in detail below.

[0007] Fig. 6 illustrates a process for extruding a cable jacket using a conventional extrusion mold, and Fig. 7 illustrates a cross-sectional view of an optical cable manufactured using the extrusion mold illustrated in Fig. 6.

[0008] As illustrated in FIG. 6, in a cable jacket extrusion mold according to the prior art, the rip cord (30) is supplied between the core penetration portion (220) of the nipple (200) and the extruded material (20') applied to the cable core (C) along the length direction of the cable core (C) while the cable core (C) is drawn out at a constant speed.

[0009] In the conventional extrusion process, the ripcord (30) is inserted into an area for forming a notch on the inner surface of the cable jacket among the extruded product outlets of the nipple, and the extruded product (20') extruded from the extruded product outlet (410) is applied to the outside of the ripcord (30), so that the ripcord (30) can be extruded so that it is placed inside the notch (21) formed on the inner surface of the cable jacket (20).

[0010] As shown in Fig. 7, when manufacturing an optical cable (100) using a cable jacket extrusion mold and a cable manufacturing method according to the prior art, there was a problem in that the rip cord (30) was disposed outside the notch (21) area formed on the inner surface of the cable jacket (20) and in a space between the cable jacket (20) and the cable core (C) other than the notch (21) formation space.

[0011] Here, the cause may be that the magnitude of the tensile force applied to each of the cable core (C) and the ripcord (30) is different during the process of drawing out the cable core (C) and the ripcord (30) in the longitudinal direction, or that the ripcord is pushed by the viscosity of the extrudate, or that the ripcord moves into the empty space between the core (C) and the cable jacket (20) after the extrudate is cooled.

[0012] If the ripcord of the optical cable is not accommodated inside the notch and is placed in a different space between the cable core and the cable jacket where the notch is not formed, the worker needs more work to expose the ripcord, which significantly reduces workability, and a mistake that damages the cable core or optical unit inside the cable jacket may occur during the process of stripping the cable jacket to expose the ripcord located in a location other than the notch.

[0013] In order to prevent such a problem, a method was attempted in which an adhesive material such as EAA (Ethylene Acrylic Acid) was coated on the outer surface of the ripcord and the ripcord was adhered to the inner space of the notch using the adhesive material to fix the ripcord inside the notch.

[0014] However, since this conventional method requires a separate process for coating the adhesive material on the ripcord and the adhesive material for the ripcord, the overall manufacturing cost of the cable increases, and during the cable manufacturing process, the adhesive material coated on the outer surface of the ripcord is detached or separated, and foreign substances such as the adhesive material are introduced into the core and contaminate the optical units, which causes a deterioration in the quality of the optical cable.

[0015] Therefore, a new method is required to stably secure a ripcord to a notch area formed in the cable jacket of an optical cable.

[0016] The present invention aims to provide a cable jacket extrusion mold capable of stably receiving a rip cord for stripping a cable jacket in a notch area formed on the inner surface of the cable jacket during the extrusion process of the cable jacket, a method for manufacturing a cable, and an optical cable manufactured through the same.

[0017] In order to solve the above problem, the present invention provides a method for manufacturing an optical cable, comprising: a core supply step of supplying a cable core including a plurality of optical units; an extrusion step of supplying an extrudate, one or more ripcords, and a plurality of tension members to the outside of the cable core; and a jacket forming step of cooling the extrudate to form a cable jacket; wherein the one or more ripcords and the plurality of tension members are supplied through the extrudate, and in the jacket forming step, the plurality of tension members are embedded in the cable jacket, and the ripcord is partially embedded in the inner peripheral surface side of the cable jacket.

[0018] Here, the cable core may include a plurality of optical units including a plurality of optical fibers and a bundle member wrapping the plurality of optical units.

[0019] In addition, one or more notches are formed on the inner surface of the cable jacket, and the rip cord can be disposed in the notches so as to be partially embedded on the inner surface of the cable jacket.

[0020] Furthermore, in order to solve the above problem, the present invention provides an optical cable comprising: a plurality of optical units including a plurality of optical fibers and a bundle member wrapping the plurality of optical units; a cable core including the plurality of optical units; a cable jacket formed by cooling an extrudate that accommodates the cable core; a plurality of tensile members built into the cable jacket; and at least one rip cord disposed between the cable jacket and the cable core; wherein, in a cable manufacturing step, the at least one rip cord is supplied by penetrating the extrudate, so that the rip cord is disposed to be partially embedded in the inner peripheral surface of the cable jacket.

[0021] Here, one or more notches are formed on the inner surface of the cable jacket, and the ripcord can be disposed in the notches so as to be partially embedded on the inner surface of the cable jacket.

[0022] Additionally, an identification means may be formed in an area corresponding to the position where the notch is formed among the outer peripheral areas of the cable jacket.

[0023] Furthermore, in order to solve the above problem, the present invention provides an extrusion mold for extruding a cable jacket of a cable including a cable core, a cable jacket having a notch formed on an inner surface thereof while surrounding the cable core, and a rip cord provided inside the notch, comprising: a main body; a core penetration portion formed by a core penetration tube at the center of the main body portion and through which the cable core passes; at least one rip cord supply port formed spaced apart from the core penetration portion so that the rip cord is supplied to the main body portion spaced apart from the cable core; and at least one tensile member supply port for supplying a tensile member embedded in the cable jacket to the main body portion; And, a die disposed in front of the nipple and having an inner circumference corresponding to the outer circumference of the main body of the nipple; an extrudate flow path is formed between the outer circumference of the main body of the nipple and the inner circumference of the die through which a molten extrudate for extruding a cable jacket can be supplied, and an extrudate outlet is formed at the end of the extrudate flow path through which the extrudate is discharged to the outer circumference of the cable core applied to the die in the outlet region of the core penetration portion of the nipple, and the ripcord supply port is disposed radially outwardly from the core penetration portion.

[0024] Here, the lip cord supply port can be formed parallel to the core penetration portion and along the longitudinal direction of the core penetration portion.

[0025] In this case, a pair of the above-mentioned ripcord supply ports may be provided at positions symmetrical to the reference point of the core penetration portion.

[0026] In addition, the extrusion outlet may have a protrusion having a shape that protrudes radially in at least a portion of the core penetration tube to form a notch, which is a space on the inner surface of the cable jacket in which the ripcord is received, and the ripcord supply port may be arranged radially outside the protrusion.

[0027] In addition, the tension member supply port can be formed parallel to the longitudinal direction of the core penetration portion at a position radially spaced from the core penetration portion.

[0028] Additionally, the ripcord supply port and the tension member supply port may be formed at positions spaced apart from each other in the circumferential direction.

[0029] In addition, the ripcord supply port may be provided radially outside the tension member supply port.

[0030] According to the cable jacket extrusion mold, cable manufacturing method and optical cable manufactured thereby according to the present invention, an optical cable having a structure in which a portion of a rip cord is embedded within the cable jacket can be manufactured, so that the rip cord can be stably accommodated or fixed in a notch area formed on the inner surface of the cable jacket.

[0031] According to the cable jacket extrusion mold, cable manufacturing method and optical cable manufactured through the same according to the present invention, the positional error of the rip cord is reduced, thereby reducing the product defect rate and consistently improving the workability of the optical cable stripping operation, and damage to the optical unit that may occur during the stripping process in an area other than the notch due to the positional deviation of the rip cord can also be prevented.

[0032] Figure 1 illustrates a cross-sectional view of one embodiment of an optical cable according to the present invention.

[0033] Figure 2 illustrates a side cross-sectional view of a cable jacket extrusion mold according to the present invention.

[0034] Figure 3 illustrates a front view of a nipple, which is a component of a cable jacket extrusion mold according to the present invention.

[0035] FIG. 4 is a side cross-sectional view of the nipple illustrated in FIG. 3, which is a component of a cable jacket extrusion mold according to the present invention.

[0036] Figure 5 illustrates a process for extruding a cable jacket using a cable jacket extrusion mold according to the present invention.

[0037] Figure 6 illustrates a process for extruding a cable jacket using a conventional extrusion mold.

[0038] Figure 7 shows a cross-sectional view of an optical cable manufactured by the process illustrated in Figure 6.

[0039] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosure is thorough and complete, and to sufficiently convey the spirit of the invention to those skilled in the art. Like reference numbers designate like elements throughout the specification.

[0040] Figure 1 illustrates a cross-sectional view of one embodiment of an optical cable according to the present invention.

[0041] As illustrated in FIG. 1, an optical cable (100) according to the present invention includes a plurality of optical units (10) including a plurality of optical fibers (11) and a bundle member (12) accommodating the plurality of optical fibers (11), a cable core (C) including the plurality of optical units (10), a cable jacket (20) formed by cooling an extrudate accommodating the cable core (C), a plurality of tensile members (40) built into the cable jacket (20), and at least one rip cord (30) disposed between the cable jacket (20) and the cable core (C), and in the cable manufacturing step, the at least one rip cord (30) is supplied by penetrating the extrudate, so that the rip cord (30) can be disposed to be partially embedded in the inner peripheral surface of the cable jacket (20).

[0042] An optical cable (100) according to the present invention can be manufactured by a cable manufacturing method including a core supply step of supplying a cable core (C) including a plurality of optical units (10); an extrusion step of supplying an extrudate, one or more ripcords (20) and a plurality of tension members (40) to the outside of the cable core (C); and a jacket forming step of cooling the extrudate to form a cable jacket (20). Here, the one or more ripcords (30) and the plurality of tension members (40) are supplied by penetrating the extrudate, and in the jacket forming step, the plurality of tension members (40) are embedded in the cable jacket (20), and the ripcord (30) may be partially embedded in the inner peripheral surface side of the cable jacket (20).

[0043] The above cable core (C) can be formed by binding a plurality of optical units (10) by means of a binding means (not shown) that wraps around the outer circumference of the plurality of optical units (10) in a state where the plurality of optical units (10) are twisted and assembled at a predetermined pitch. Here, the binding means (not shown) can be in the form of a binding tape or binding yarn.

[0044] The plurality of optical units (10) constituting the above cable core (C) may each be configured to include a plurality of optical fibers (11) and a bundle member (12) that accommodates the plurality of optical fibers (11). Here, the bundle member (12) may be a means for gathering the plurality of optical fibers (11), such as a tube, binder yarn, binder tape, etc.

[0045] As illustrated in FIG. 1, the optical cable (100) comprises a plurality of optical fibers (11) constituting the optical unit (10) to accommodate multi-core optical fibers inside the cable core (C) and can be assembled into the bundle member (12) in the form of a plurality of rollable optical fiber ribbons.

[0046] The above-mentioned rollable optical fiber ribbon (11R) may have a structure in which a plurality of optical fibers (11) are arranged in a longitudinal direction in parallel, and a pair of adjacent optical fibers (11) among the plurality of optical fibers (11) are bonded with a bonding material.

[0047] The above bonding material may include a UV-curable resin or the like, and the bonding material may be intermittently applied along the longitudinal direction of the optical fiber (11) in the area between a pair of optical fibers (11), thereby enabling width-wise rolling of the optical fiber ribbon (11R).

[0048] Since the above-mentioned rollable optical fiber ribbon (11R) is configured to be able to roll in the width direction, it can be assembled by the bundle member (12) in a curved shape based on the cable cross-section.

[0049] In addition, the bundle member (12) constituting the optical unit (10) may be configured so that the shape of the cross section changes depending on the presence or absence of surrounding units or empty space when placed inside the cable jacket (20) while a plurality of optical fibers (11) are accommodated therein.

[0050] The bundle member (12) constituting the optical unit (10) can be transformed into a circular, oval or polygonal shape in a cross-section perpendicular to the longitudinal direction of the optical cable, and when the bundle member (12) is a tube, it can be made of a material that is thin or has relatively low hardness, low elastic modulus or is flexible, and whose shape can be changed in response to the shape of the space arranged within the cable jacket (20).

[0051] In addition, the optical cable (100) according to the present invention may have at least one notch (21) formed on the inside of the cable jacket (20), and the ripcord (30) may be provided inside each of the notches (21).

[0052] In this way, the optical cable (100) according to the present invention has at least one notch (21) formed on the inner surface of the cable jacket (20) and a rip cord (30) provided inside the notch (21), so that the cable jacket (20) can be easily removed by using the rip cord (30) provided inside the notch (21) to expose the cable core (C) during a connection process with another optical fiber, such as an intermediate branch of the optical cable (100).

[0053] In the embodiment illustrated in Fig. 1, the notches (21) are provided in total in two numbers, and are illustrated as being formed one at each of the two notches (21) facing each other, but the number may be increased or decreased.

[0054] The above notch (21) may be formed in a groove shape with rounded corners on the inside of the cable jacket (20) to prevent the cable core (C) or optical unit (10) from being damaged when the cable jacket (20) is removed, and the notch (21) may be formed in a shape in which the thickness of the cable jacket (20) decreases in the radial direction of the cable on the inner surface of the cable jacket (20).

[0055] In this way, the optical cable (100) according to the present invention has at least one notch (21) formed on the inner surface of the cable jacket (20), so that an empty space is formed between the cable jacket (20) and the cable core (C), and a region of the cable jacket (20) having a thickness thinner than the thickness of the cable jacket (20) in the region where the notch (21) is not formed is formed. Therefore, the cable jacket (20) can be removed longitudinally in the region where the notch (21) is located, or the rip cord (30) inside the notch (21) can be partially exposed without damaging it, and then the cable jacket (20) can be torn and stripped by pulling the rip cord (30).

[0056] Furthermore, the optical cable (100) according to the present invention may be configured to further include a plurality of tensile members (40) embedded in the length direction of the cable inside the cable jacket (20), and the tensile members (40) serve to reinforce the tensile strength or tensile strength of the cable.

[0057] The above tensile member (40) may be composed of a wire or fiber-reinforced plastic material, and may be provided along the length of the cable by being embedded inside the cable jacket (20) when the cable jacket (20) is extruded.

[0058] A plurality of tension members (40) can be arranged at positions symmetrical to each other with respect to the center of the cable.

[0059] In addition, the optical cable (100) according to the present invention may have an identification means (50) such as a stripe, a protrusion, or a groove formed in an area corresponding to the position where the notch (21) is formed among the outer peripheral area of ​​the cable jacket (20).

[0060] The above identification means (50) enables external identification of which area of ​​the inner surface of the cable jacket (20) the notch (21) is formed in without directly opening the inside by removing the cable jacket (20).

[0061] The optical cable (100) is provided with an identification means (50), so that when a worker removes the cable jacket (20) in the area where the identification means (50) is located, a notch (21) formed on the inner surface of the cable jacket (20) is opened, and the cable core (C) or ripcord (30) arranged in the extruded product path (400) of the notch (21) can be exposed without being damaged.

[0062] Meanwhile, the optical cable (100) according to the present invention has at least one notch (21) formed on the inner surface of the cable jacket (20) as described above, and the ripcord (30) can be accommodated in each notch (21).

[0063] The present invention aims to solve the problem of product defects and reduced workability caused by the ripcord not being positioned inside the notch and being displaced in a conventional optical cable, by changing the structure of the extrusion mold so that the ripcord (30) is stably positioned inside the notch (21) during the extrusion process of the cable jacket, thereby minimizing the phenomenon of the ripcord being displaced.

[0064] Hereinafter, with reference to FIGS. 2 to 5, a cable jacket extrusion mold for manufacturing an optical cable (100) according to the present invention will be described in detail.

[0065] FIG. 2 illustrates a side cross-sectional view of a cable jacket extrusion mold according to the present invention, FIG. 3 illustrates a front view of a cable jacket extrusion mold according to the present invention, FIG. 4 illustrates a side cross-sectional view of a nipple illustrated in FIG. 3, which is a component of a cable jacket extrusion mold according to the present invention, and FIG. 5 illustrates a process of extruding a cable jacket using a cable jacket extrusion mold according to the present invention.

[0066] As illustrated in FIGS. 2 to 5, a cable jacket extrusion mold according to the present invention is for extruding a cable jacket (20) of a cable (100) including a cable core (C), a cable jacket (20) having a notch (21) formed on an inner surface to surround the cable core (C), and a rip cord (30) provided inside the notch (21), and may be configured to include a nipple (200) and a die (300).

[0067] The above nipple (200) is configured to include a main body (210); a core penetration portion (220) formed by a core penetration tube (221) at the center of the main body (210) and through which the cable core (C) passes; at least one ripcord supply port (240) formed spaced apart from the core penetration portion (220) so that the ripcord (30) is supplied to the main body (210) spaced apart from the cable core (C); and at least one tensile member supply port (240h) for supplying a tensile member (40) embedded in the cable jacket (20) to the main body (210).

[0068] The above main body (210) may be made of a high-strength material, such as a metal material such as iron, brass, or stainless steel, to ensure durability and wear resistance in high-temperature and high-pressure environments.

[0069] The above die (300) may be placed in front of the nipple (200) and may have an inner surface having a shape corresponding to the outer surface of the main body (210) of the nipple (200).

[0070] In addition, by the relative arrangement of the nipple (200) and the die (300), an extrudate flow path (400) is formed between the outer surface of the main body (210) of the nipple (200) and the inner surface of the die (300) through which a molten extrudate for extruding a cable jacket can be supplied, and at the end of the extrudate flow path (400), an extrudate outlet (410) is formed to form a cable jacket (20) by ejecting the extrudate to the outer surface of the cable core (C) applied to the die (300) in the outlet region of the core penetration portion (220) of the nipple (200).

[0071] The extrudate (20') injected into the extrudate flow path (400) is extruded from the extrudate outlet (410) after flowing and can be applied to the outer surface of the cable core (C) to form a cable jacket. Here, the extrudate (20') is a cable jacket (20) material in a molten and heated state.

[0072] FIG. 4 is a side cross-sectional view of the cable jacket extrusion mold taken along the AA' section of FIG. 3, which is a front view of the nipple (200), which is a cable jacket extrusion mold according to the present invention, and FIG. 2 is a side cross-sectional view of the extrusion mold in which the nipple (200) and die (300) are arranged.

[0073] As illustrated in FIG. 2, the shape of the main body (210) is configured as an inclined shape in which the cross-sectional area of ​​the extrudate flow path of the main body (210) gradually decreases as it goes toward the extrudate outlet (410) based on the cross-section perpendicular to the supply direction of the cable core (C), so that the extrudate (20') injected into the extrudate flow path (400) of the main body (210) can be pressurized and delivered to the extrudate outlet (410).

[0074] A core penetration portion (220) having a circular cross-section can be formed at the center of the main body portion (210), and the core penetration portion (220) can be formed long in the supply direction of the cable core (C) at the center of the main body portion (210).

[0075] The above core penetration portion (220) can penetrate the cable core (C) in the longitudinal direction, and the cable core (C) introduced to the rear of the core penetration portion (220) can exit through the core penetration portion (220).

[0076] As illustrated in Fig. 3, the core penetration portion (220) can be formed by the core penetration tube (221). Accordingly, the extrudate (20') injected into the extrudate flow path (400) is extruded from the extrudate outlet (410), so that the extrudate (20') can be applied to the circumferential area of ​​the cable core (C).

[0077] In addition, the cross-section of the core penetration tube (221) may have a protrusion (230) formed at a position corresponding to the area where the ripcord supply port (240) is formed among the entire circumferential area of ​​the core penetration tube (221).

[0078] As illustrated in FIG. 3, a pair of protrusions (230) formed on the cross-section of the core penetration pipe (221) with respect to the cross-section perpendicular to the supply direction of the cable core (C) may have a shape that protrudes outward along the radial direction of the nipple (200).

[0079] When the number of ripcords (30) increases, the number of protrusions (230) on the ripcord supply port (240) and the core penetration pipe (221) can also be formed at corresponding positions.

[0080] At least one protrusion (230) may be formed on the cross section of the core penetration tube (221) so that at least one notch (21) may be formed on the inner surface of the cable jacket (20).

[0081] Specifically, since the cross-section of the core penetration tube (221) is configured to include the protrusion (230), the extruded material (20') extruded along the cross-sectional shape of the core penetration tube (221) is extruded at a predetermined distance from the cable core (C) arranged inside the core penetration portion (220) along the longitudinal direction of the cable core (C) in the region of the protrusion (230), so that a notch (21) can be formed on the inner surface of the cable jacket as a result.

[0082] The cable jacket extrusion mold according to the present invention may be provided with a ripcord supply port (240) through which a ripcord (30) is supplied at a position radially spaced from the core penetration portion (220) through the extruded material passage.

[0083] At least one ripcord (30) can be introduced from one side of the nipple body (210) along the ripcord supply port (240) and then withdrawn from the other side of the nipple body (210).

[0084] The above ripcord supply port (240) may be formed parallel to a position spaced outward in the radial direction of the core penetration portion (220) from the main body portion (210). The ripcord supply port (240) may be formed parallel to the core penetration portion (220) along the longitudinal direction of the core penetration portion (220). When a plurality of ripcord supply ports (240) are provided, the plurality of ripcord supply ports (240) may be formed spaced apart from each other in parallel.

[0085] In addition, referring to FIG. 3, the ripcord supply port (240) is formed to partially cross the molten material path, so that the supplied ripcord can pass through the main body (210) and be discharged in the direction of the extruded material outlet.

[0086] Here, the outlet of the ripcord supply port (240) may be provided within an area (θ) formed by two imaginary lines connecting the two points where the protrusion (230) is formed in the core penetration tube (221) from the center of the core penetration portion (220), and preferably, may be provided on an extension line connecting a pair of protrusions (230) formed in the core penetration tube (221).

[0087] The above-mentioned tension member supply port (240h) can be configured in the same manner as the above-mentioned ripcord supply port (240). That is, the cable jacket extrusion mold according to the present invention has a tension member supply port (240h) formed through the main body (210) and through which the tension member (40) is supplied at a position radially spaced from the core penetration portion (220).

[0088] The above tensile member supply port (240h) and the above ripcord supply port (240) have a difference in inner diameter size according to the difference in diameter between the tensile member and the ripcord, but the formation position and method are similar to those of the above ripcord supply port (240).

[0089] However, there is a difference in that the ripcord supply port (240) is provided radially outside a pair of protrusions (230) formed in the core penetration pipe (221), while the tension member supply port (240h) is formed outside the extruded product outlet (410), but no protrusions exist inside.

[0090] A pair of ripcord supply ports (240) and a pair of tension member supply ports (240h) may be formed in the main body (210), and the pair of ripcord supply ports (240) are each provided at a position in the region where the protrusions (230) of the core penetration pipe (221) are formed, and the pair of tension member supply ports (240h) may be arranged symmetrically with respect to the pair of ripcord supply ports (240) at equal intervals as much as possible.

[0091] Accordingly, as shown in FIG. 3, a pair of protrusions (230) of the core penetration tube (221) and a ripcord supply port (240) on the outer side thereof are formed at 180-degree intervals, and the tension member supply port (240h) can be formed at a symmetrical position at 90-degree intervals with respect to the ripcord supply port (240).

[0092] Furthermore, the die (300) according to the present invention may be configured to include a circular die outlet pipe (310) through which the extrudate (20') applied on the outer surface of the cable core (C) passes, so as to make the outer surface shape of the cable jacket formed by extruding the extrudate (20') circular.

[0093] The die outlet pipe (310) may have a hollow space (not shown) formed therein through which the cable core (C) can pass. As the cable core (C) to which the extruded material is applied passes through the hollow space of the die outlet pipe (310), the extruded material (20') surrounding the outer circumferential surface of the cable core (C) passes through the die outlet pipe (310) and is formed into a circular shape.

[0094] Since the above extruded product (20') begins to cool and harden from the time it is discharged from the extruded product outlet (410), it may be extruded onto the outer surface of the cable core (C) and have an uneven surface, but it can be formed into a uniform shape and hardened as it passes through the die outlet pipe (310) to become a cable jacket.

[0095] Referring to FIG. 5, the present invention can provide a cable jacket extrusion method that supplies an extrudate at a constant hourly flow rate to an extrudate flow path (400) of the cable jacket extrusion mold described above, supplies a cable core (C) by penetrating it through the core penetration portion (220), and supplies a ripcord (30) to the ripcord supply port (240) to extrude a cable jacket (20).

[0096] The above cable core (C) is covered with an extruded material, and the covered cable core (C) and the ripcord (30) may be each included in the cable jacket (20) of the optical cable (100) at the rear of the die (300) and pulled in the longitudinal direction at a preset line speed.

[0097] The ripcord (30) drawn out from the ripcord supply port (240) is embedded in the extrudate on the side of the ripcord supply port (240), but as it moves toward the extrudate outlet (410), it is pushed toward the inside of the uncured extrudate and can move toward the center of the core penetration portion (220).

[0098] Accordingly, the ripcord (30) is completely embedded in the extruded product (20') and pulled out near the ripcord supply port (240), but due to the state of the uncured extruded product and the tensile force applied to the ripcord (30), it moves toward the center of the core penetration portion (220), and finally, the ripcord (30) is arranged on the inside of the extruded product (20'), i.e., in the notch (21) area, so that a portion of it can be embedded inside the cable jacket (20).

[0099] Preferably, only a portion of the ripcord (30) is buried in the inner surface of the notch (21) area inside the cable jacket (20), so that the ripcord (30) can be stably positioned at a desired position, and at the same time, the inner surface of the cable jacket (20) can be removed at once when the cable jacket (20) is removed through the ripcord (30).

[0100] In this case, the ripcord (30) digs into the inside of the extruded material (20') applied on the cable core (C) as it moves toward the center of the core penetration portion (220) and is placed on the inside of the extruded material (20'), so when examining the cross-sectional structure of the optical cable (100) manufactured using the cable jacket extrusion mold according to the present invention, a part of the ripcord (30) may be partially embedded or attached to the inside of the cable jacket (20).

[0101] In this way, the positions of the ripcord and notch can be aligned evenly, reducing the defect rate and cost, and thus providing consistent quality and workability.

[0102] And each tension member (40) can be inserted along a pair of tension member insertion paths provided on both sides of the core penetration portion (220) and then pulled out of the nipple (200). At this time, the direction of movement of the tension member (40) can be parallel to the direction of the cable core (C).

[0103] Here, the extruded material (20') is applied between the tensile member (40) and the cable core (C) and to the outer area of ​​the tensile member (40), so that the tensile member (40) can be embedded inside the cable jacket (20).

[0104] And, as shown in Fig. 3, the tension member supply port (240h) does not have a protrusion (230) on the inner core penetration pipe (221), so that a notch (21) is not formed, and the tension member (40) can also remain embedded in the cable jacket (20) without being exposed to the inner surface of the cable jacket (20).

[0105] While this specification has described preferred embodiments of the present invention, those skilled in the art will appreciate that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention as defined in the claims below. Therefore, any modified implementation that fundamentally includes the elements of the claims should be considered within the technical scope of the present invention.

Claims

1. In the method of manufacturing an optical cable, A core supply step for supplying a cable core including a plurality of optical units; An extrusion step for supplying an extruded material, one or more ripcords and a plurality of tensile members to the outer surface of the cable core; and A jacket forming step of cooling the extruded material to form a cable jacket; The one or more ripcords and the plurality of tensile members are supplied through the extruded body, In the above jacket forming step, the plurality of tensile members are embedded in the cable jacket, A cable manufacturing method characterized in that the above ripcord is partially embedded in the inner surface side of the cable jacket.

2. In paragraph 1, A cable manufacturing method characterized in that the cable core includes a plurality of optical units including a plurality of optical fibers and a bundle member wrapping the plurality of optical units.

3. In paragraph 1, One or more notches are formed on the inner surface of the above cable jacket, A cable manufacturing method characterized in that the ripcord is partially embedded in the inner circumferential surface of the cable jacket in the above notch.

4. A plurality of optical units including a plurality of optical fibers and a bundle member wrapping the plurality of optical units; A cable core comprising the plurality of optical units; A cable jacket formed by cooling an extruded material that accommodates the cable core; A plurality of tensile members built into the above cable jacket; and comprising one or more ripcords disposed between the cable jacket and the cable core; An optical cable characterized in that, in the cable manufacturing step, the one or more ripcords are supplied by penetrating the extruded material, so that the ripcords are partially embedded and arranged on the inner surface side of the cable jacket.

5. In paragraph 4, One or more notches are formed on the inner surface of the above cable jacket, An optical cable characterized in that the ripcord is partially embedded in the inner circumferential surface of the cable jacket in the above notch.

6. In paragraph 4, An optical cable characterized in that an identification means is formed in an area corresponding to a position where the notch is formed among the outer peripheral area of ​​the cable jacket.

7. In an extrusion mold for extruding a cable jacket of a cable including a cable core, a cable jacket having a notch formed on the inner surface while wrapping the cable core, and a ripcord provided inside the notch, A nipple including a main body portion; a core penetration portion formed by a core penetration tube in the center of the main body portion and through which the cable core passes; at least one ripcord supply port formed spaced apart from the core penetration portion so that the ripcord is supplied to the main body portion spaced apart from the cable core; and at least one tension member supply port for supplying a tension member embedded in the cable jacket to the main body portion; and, A die is disposed in front of the nipple and has an inner surface having a shape corresponding to the outer surface of the main body of the nipple; An extrudate flow path is formed between the outer surface of the main body of the above nipple and the inner surface of the above die, through which molten extrudate for cable jacket extrusion can be supplied, At the end of the above extrusion flow path, an extrusion outlet is formed through which the extrusion is discharged to the outer surface of the cable core applied to the die in the outlet area of ​​the core penetration portion of the nipple. A cable jacket extrusion mold characterized in that the above ripcord supply port is arranged radially outwardly from the core penetration portion.

8. In paragraph 7, A cable jacket extrusion mold characterized in that the above ripcord supply port is formed parallel to the core penetration portion along the longitudinal direction of the core penetration portion.

9. In paragraph 8, A cable jacket extrusion mold characterized in that the above ripcord supply port is provided in pairs at positions symmetrical to the reference point of the core penetration portion.

10. In paragraph 7, The extrusion outlet has a protrusion having a shape that protrudes radially in at least a portion of the core penetration tube to form a notch, which is a space on the inner surface of the cable jacket in which the ripcord is received. A cable jacket extrusion mold characterized in that the above-mentioned ripcord supply port is positioned radially outside the above-mentioned protrusion.

11. In paragraph 7, A cable jacket extrusion mold characterized in that the above tensile member supply port is formed parallel to the longitudinal direction of the core penetration portion at a position radially spaced from the core penetration portion.

12. In paragraph 7, A cable jacket extrusion mold characterized in that the above-mentioned ripcord supply port and the above-mentioned tensile member supply port are formed at positions spaced apart in the circumferential direction.

13. In paragraph 12, A cable jacket extrusion mold characterized in that the above ripcord supply port is provided radially outside the above tension member supply port.

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