WO2008120850A1

WO2008120850A1 - Optical cable lead-in clamp

Info

Publication number: WO2008120850A1
Application number: PCT/KR2007/005841
Authority: WO
Inventors: Eui Keon Lee; Bun Hee Park
Original assignee: EUN JIN CO Ltd
Current assignee: EUN JIN CO Ltd
Priority date: 2007-03-30
Filing date: 2007-11-21
Publication date: 2008-10-09
Anticipated expiration: 2009-09-30
Also published as: TW200909898A; KR20080089137A

Abstract

Disclosed therein is an optical cable lead-in clamp for supporting and anchoring an optical cable connected from an electric pole to a house. The optical cable lead-in clamp includes a housing (20), a guiding holder (30), a guiding column (40), and a nut (60). The housing (20) has a front face (22), a rear face (24), and a finger stop (90) mounted on a side thereof. The guiding holder (30) is mounted on the other side of the housing (20), which is opposed to the side where the finger stop (90) is mounted, protrudes forwardly from the front face (22) of the housing (20), and has a guiding surface (32) formed vertically in an arc shape. The guiding column (40) is mounted on the housing (20) between the guiding holder (30) and the finger stop (90), protrudes forwardly from the front face (22) of the housing (20), and has a guiding surface (42) and a screw surface (44) formed in a round shape. The nut (60) is engagedly coupled to the screw surface (44) of the guiding column (40). Through the above configuration, the optical cable (1) is wound and coupled along the guiding surface (32) of the guiding holder (30) and the guiding surface (42) of the guiding column (40) and led in and out in a direction of the guiding column (40).

Description

[DESCRIPTION] [Invention Title]

OPTICAL CABLE LEAD-IN CLAMP [Technical Field]

The present invention relates to an optical cable lead-in clamp, and more particularly, to an optical cable lead-in clamp for supporting and anchoring an optical communication cable connected from an electric pole to a house. [Background Art]

In general, a communication cable connected to a house is connected to an electric pole via an underground communication pipeline, and then, is connected from the electric pole to the house.

In this instance, the communication cable connected from the electric pole to the house is supported and anchored by a cable clamp adapted to protect the communication cable. Such a cable clamp serves to induce a direction of the cable led into the house and to prevent drooping of the cable or protect the cable from the external shock.

As described above, for the cable clamp for supporting and fixing the cable, Japanese Patent Laid-open No. 2004-95305 entitled "binding pulley insulator for lowering high pressure and method of anchoring insulating wire for lowering high pressure" discloses a structure of twisting and anchoring a cable in zigzags.

However, a cable clamp according to the prior art has a problem in that a transmission speed gets slow and the cable gets damaged by shock applied to the cable (is the general term for self-weight, wind, a tensile force applied from the outside, and so on) since the cable is twisted in zigzags. Particularly, since the introduction of an optical cable, the cable clamp stands out in bold relief in the problem of a lowering of the transmission speed and a damage of the optical cable due to the twisting of the cable.

In the meantime, Japanese Patent Laid-open No. 2004-343834 entitled "outdoor wire anchor and outdoor wire managing method using the same" and Korean Utility Model Registration No. 20-0395497 entitled "clamp for anchoring cable" respectively disclose cable clamps, each of which is anchored by a separate steel wire, for supporting a cable to the steel wire (and for supporting the cable on the cable clamp) and inducing the cable to a house.

The cable clamp according to the above technology can minimize transformation of the optical cable to thereby minimize the lowering of the transmission speed and the damage of the optical cable, but has a problem in that the optical cable cannot be effectively anchored. That is, a company using the cable clamp like Korea Telecom (KT) demands to fix the optical cable with more than a predetermined tensile force not to move when the optical cable is anchored by the cable clamp. However, the cable clamps according to the prior arts have a problem in that they cannot satisfy the above demand.

Meanwhile, Japanese Patent Laid~open No. 5-153716 entitled "clamp for anchoring wires having different diameter" and Japanese Patent Laid-open Publication No. 6-153369 entitled "wire clamp" respectively disclose cable clamps for supporting and anchoring untwisted cable to thereby minimize transformation of the cable.

However, the cable clamp according to the above prior arts have a problem in that they may cause a loss of a transmission signal due to a sudden transformation of the cable (especially, optical cable) since the cable is bent at right angles when the cable is led in (when the cable clamp is mounted on an electric pole) or led out (when the cable clamp is mounted in the house) .

[Disclosure]

[Technical Problem]

Accordingly, the present invention has been made in an effort to solve the above-mentioned problems occurring in the prior arts, and it is an object of the present invention to provide a new type optical cable lead-in clamp, which can minimize a transformation of the optical cable and a loss of a transmission signal when the optical cable is led in from an electric wire to a house.

Particularly, the present invention provides a new type optical cable lead-in clamp, which can lead in the optical cable in a round type without any twisted portion when the optical cable is induced, minimize a loss of a transmission signal while maximizing power for anchoring the optical cable (anchoring force), and anchor the optical cable more stably even when a tensile force is applied to the optical cable. [Technical Solution]

To achieve the above objects, in an aspect of the present invention, the present invention provides an optical cable lead-in clamp for supporting and anchoring an optical cable (1) connected from an electric pole to a house comprising: a housing (20) having a front face (22), a rear face (24), and a finger stop (90) mounted on a side thereof; a guiding holder (30) mounted on the other side of the housing (20), which is opposed to the side where the finger stop (90) is mounted, the guiding holder (30) protruding forwardly from the front face (22) of the housing (20) and having a guiding surface (32) formed vertically in an arc shape; a guiding column (40) mounted on the housing (20) between the guiding holder (30) and the finger stop (90), the guiding column (40) protruding forwardly from the front face (22) of the housing (20) and having a guiding surface (42) and a screw surface (44) formed in a round shape; and a nut (60) engagedly coupled to the screw surface (44) of the guiding column (40), wherein the optical cable (1) is wound and coupled along the guiding surface (32) of the guiding holder (30) and the guiding surface (42) of the guiding column (40) and led in and out in a direction of the guiding column (40).

The screw surface (44) of the guiding column (40) has a thread formed to have a direction in which the nut is fastened to the guiding column (40) when the nut (60) is rotated with respect to a direction in which a tensile force is exerted to the optical cable (1). The optical cable lead-in clamp further comprises: an additional guiding holder (30') and an additional guiding column (40') respectively formed on the rear face (24) of the housing (20) and having the same structures as those of the guiding holder (30) and the guiding column (40), the additional guiding holder (30') and the additional guiding column (40') being formed symmetrically to the guiding holder (30) and the guiding column (40) relative to the housing 20; and additional nut (60') having the same structure as the nut (60) and coupled to the additional guiding column (40').

The housing (20), the guiding holder (30) and the guiding column (40) are injection-molded of a plastic material in such a way as to be formed integrally with one another.

The guiding column (40) further includes a stopper (46) extending upwardly from the screw surface (44), and the nut (60) further includes a locking flange (64) caught to the stopper (46) when it is coupled to the guiding column (40).

In another aspect of the present invention, the present invention provides an optical cable lead-in clamp for supporting and anchoring an optical cable (1) connected from an electric pole to a house, comprising: a housing (20) having a flat front face (22) and a finger stop (90) mounted on a side thereof; a guiding holder (30) formed integrally with the other side of the housing (20), which is opposed to the side where the finger stop (90) is mounted, the guiding holder (30) protruding forwardly from the front face (22) of the housing (20) and having a guiding surface (32) formed vertically in an arc shape and a guiding flange (34) outwardly extending from the guiding surface (32) at the front end thereof in such a way as to have a guiding space (33) defined between the front face (22) of the housing (20) and the guiding flange (34); a guiding column (40) formed integrally with the housing (20) between the guiding holder (30) and the finger stop (90), the guiding column (40) protruding forwardly from the front face (22) of the housing (20) and having a guiding surface (42) and a screw surface (44) formed in a round shape and a screw surface (44) extending forwardly from the guiding surface (42); and a nut (60) engagedly coupled to the screw surface (44) of the guiding column (40), wherein the optical cable (1) is wound and coupled along the guiding surface (32) of the guiding holder (30) and the guiding surface (42) of the guiding column (40) and led in and out in a direction of the guiding column (40).

The screw surface (44) of the guiding column (40) has a thread formed to have a direction in which the nut is fastened to the guiding column (40) when the nut (60) is rotated with respect to a direction in which a tensile force is exerted to the optical cable (1).

The nut (60) further includes a contact flange (70) having a number of projections (72) projecting from the bottom surface thereof at fixed intervals and located on the outer periphery of the guiding surface (42) of the guiding column (40).

The housing (20) further includes a flat rear face (24) opposed to the front face (22) and formed symmetrically to the front face (22); and an additional guiding holder (30') and an additional guiding column (40¹) respectively formed on the rear face (24) of the housing (20) and having the same structures as those of the guiding holder (30) and the guiding column (40), the additional guiding holder (30') and the additional guiding column (40') being formed symmetrically to the guiding holder (30) and the guiding column (40) relative to the housing 20; and an additional nut (60') having the same structure as that of the nut (60) and coupled to the additional guiding column (40'). [Advantageous Effects]

The optical cable lead-in clamp according to the present invention can minimize the transformation of the optical cable and the loss of the transmission signal since the optical cable is coupled and anchored into the clamp in an S form and is led in and out in a parallel or curved form without any twisted portion. Particularly, the optical cable lead-in clamp according to the present invention can maximize power for anchoring the optical cable (anchoring force), anchor the optical cable stably and minimize the loss of the transmission signal since it has the above lead-in, lead-out and anchoring structure and a structure that a nut (and additional nut) presses the optical cable when the tensile force is applied to the optical cable. So, the optical cable lead-in clamp according to the present invention can be effectively applied to various cables, to which a tensile force acts, especially, cables, which have a stable anchoring force against the tensile force and minimize the loss of the transmission signal, like the optical cable. [Description of Drawings]

FIG. 1 is a perspective view of an optical lead-in clamp according to a preferred embodiment of the present invention.

FIG. 2 is a perspective view showing a state where a nut is separated from the optical lead-in clamp of FIG. 1.

FIG. 3 is a view showing a state where an optical cable is coupled to the optical cable lead-in clamp according to the preferred embodiment of the present invention.

FIG. 4 is a sectional view showing essential parts of the optical cable lead-in clamp according to the preferred embodiment of the present invention.

FIG. 5 is a perspective view showing a modification of the optical cable lead-in clamp of FIG. 1.

FIG. 6 is a perspective view showing a state where a nut and additional nut are separated from the optical cable lead-in clamp of FIG. 5 according to the modification.

FIG. 7 is a sectional view showing essential parts of the optical cable lead-in clamp according to the modification.

FIG. 8 is a photograph for explaining a used example of the lead-in cable according to the preferred embodiment of the present invention. [Best Mode]

Reference will be now made in detail to the preferred embodiment of the present invention with reference to the attached figures 1 to 8. In the meantime, illustration and detailed description of configurations, functions and effects, which can be easily obtained from technologies related with general cable clamps, will be simplified or omitted, and parts related with the present invention will be mainly described.

FIG. 1 is a perspective view of an optical lead-in clamp according to a preferred embodiment of the present invention, FIG. 2 is a perspective view showing a state where a nut is separated from the optical lead-in clamp of FIG. 1, FIG. 3 is a view showing a state where an optical cable is coupled to the optical cable lead-in clamp according to the preferred embodiment of the present invention, and FIG. 4 is a sectional view showing essential parts of the optical cable lead-in clamp according to the preferred embodiment of the present invention.

Referring to FIGS. 1 to 4, the optical cable lead-in clamp 10 according to the preferred embodiment of the present invention includes a housing 20, a guiding holder 30, a guiding column 40 and a nut 60, and is used for supporting and anchoring an optical cable 1 connected from an electric pole to a house.

As shown in FIG. 3, the optical cable lead-in clamp 10 according to the present invention couples and anchors the optical cable 1 in an S shape thereto and allows the optical cable 1 to be led in and out in a parallel form or a curved form. So, the optical cable lead-in clamp 10 according to the present invention can minimize a transformation of the optical cable and a loss of a transmission signal since the optical cable is not twisted.

Referring to FIGS. 1 and 2, the housing 20 of the optical cable lead-in clamp 10 according to the present invention has a front face 22 and a rear face 24, and a finger stop 90 is mounted at a side of the housing 20. Here, as shown in FIG. 8, the finger stop 90 is used when the optical cable lead-in clamp 10 is anchored to a pole 100 such as the electric pole by an intermediate clamp 102, and may be in various forms according to the intermediate clamp 102 or an anchoring structure. Particularly, the finger stop 90 has a sufficient rigidity since it is formed by an insert injection molding of a steel wire when the housing 20 is molded. It is preferable that the front face 22 and the rear face 24 of the housing 20 are formed in flat, but in aspect of characteristics of injection-molded products, the housing 20 may additionally have a reinforcing structure or a structure for guiding the optical cable 1 if necessary.

In addition, the guiding holder 30 is mounted on the other side of the housing 20, which is opposed to the side where the finger stop 90 is mounted. The guiding holder 30 protrudes forwardly from the front face 22 of the housing 20, and has a guiding surface 32 formed vertically in an arc shape. Moreover, the guiding column 40 is mounted on the housing 20 between the guiding holder 30 and the finger stop 90, protrudes forwardly from the front face 22 of the housing 20, and has a guiding surface 42 and a screw surface 44 formed in a round shape.

In this instance, to effectively anchor the optical cable 1, the guiding holder 30 has a guiding flange 34 extending outwardly from the guiding surface 32 at the front end of the guiding holder 30 in such a way as to have a guiding space 33 defined between the guiding flange 34 and the front face 22 of the housing 20. As shown in FIG. 4, the guiding flange 34 guides and supports the optical cable 1 led in and out to thereby more effectively anchor the optical cable 1.

Furthermore, the guiding column 40 is mounted on the housing 20 between the guiding holder 30 and the finger stop 90, protrudes forwardly from the front face 22 of the housing 20, and has a guiding surface 42 and a screw surface 44 formed in a round shape. As shown in FIG. 3, through the guiding column 40 and the guiding holder 30 having the above structures, the optical cable lead-in clamp 10 according to the present invention allows the optical cable 1 to be wound and coupled along the guiding surface 32 of the guiding holder 30 and the guiding surface 42 of the guiding column 40 and led in and out and anchored in a direction of the guiding column 40, whereby the optical cable 1 can be anchored firmly without being twisted.

In addition, the nut 60 made of a plastic material and formed separately has a screw surface 62 formed on the inner surface thereof to thereby be coupled to the screw surface 44 of the guiding column 40, whereby the optical cable 1 can be anchored stably as shown in FIG. 4. Particularly, in the preferred embodiment of the present invention, the screw surface 44 of the guiding column 40 has a thread formed to have a direction in which the nut is fastened to the guiding column 40 when the nut 60 is rotated with respect to a direction in which a tensile force is exerted to the optical cable 1 (preferably, a direction that the optical cable 1 is led in or out in parallel).

For instance, as shown in FIG. 3, after the optical cable 1 is led in parallel and wound on the guiding column 40, when the optical cable 1 is wound on the guiding holder 30 and led out downwardly, even though the tensile force at the lead-in side acts to the optical cable 1, since the nut 60 acts in a direction to be wound on the guiding column 40, a compression force acts to the optical cable 1, and so, a power to anchor the optical cable 1 is increased, whereby the optical cable 1 can be effectively prevented from loosening. In this instance, since twisting of the optical cable 1 is not generated, the loss of the transmission signal can be minimized. Moreover, since the optical cable 1 is supported on the guiding column 40 even though the tensile force acts to the side where the optical cable 1 is led out, the anchoring force is increased likewise to thereby effectively prevent loosening.

In this instance, the optical cable lead-in clamp 10 according to the present invention anchors the optical cable 1 more effectively by means of the nut 60 and effectively prevents the loss caused due to a separation of the nut 60 from the guiding column 40. That is, the guiding column 40 in this embodiment includes the guiding surface 42 formed in the round shape, the screw surface 44 forwardly extending from the guiding surface 42, and a stopper 46 upwardly extending from the screw surface 44. In this instance, it is preferable that the stopper 46 is generally in a hook form and a number of the stoppers 46 are formed to provide sufficient elasticity. The nut 60 has a locking flange 64 caught to the stopper 46 when the nut 60 is coupled to the guiding column 40, so that the nut 60 is prevented from a free separation after the nut 60 is coupled to the guiding column 40. Moreover, the nut 60 further has a contact flange 70 located on the outer periphery of the guiding surface 42 of the guiding column 40 and having a number of projections 72 projecting from the bottom surface thereof at fixed intervals. Furthermore, the contact flange 70 has a clearance step 68 formed on the inner portion thereof and having the outer diameter and height larger than those of the guiding surface 42, whereby a compression level of the optical cable 1 can be adjusted as shown in FIG. 4. In addition, embossments or protrusions 66 may be formed on the outer surface of the nut 60 to make locking and unlocking of the nut 60 easy.

In the optical cable lead-in clamp 10 according to the present invention, a height of the guiding space 33 formed on the guiding holder 30 and a height of the guiding surface 42 of the guiding column 40 may be adjusted, so that the optical cable lead-in clamp 10 can be applied to optical cables having different diameters, but it is preferable to keep a stable anchoring force through a small shared range.

In the meantime, the optical cable lead-in clamp 10 according to the present invention can make manufacture easy and reduce costs since the housing 20, the guiding holder 30 and the guiding column 40 are injection- molded with the plastic material integrally with one another. Of course, it is to be appreciated that those skilled in the art can change or modify the material and molding method in various manners without departing from the technical scope and spirit of the present invention. For instance, like the finger stop 90, if necessary, the guiding holder 30 and the guiding column 40 may be formed individually and integrated with the housing 20 through the insert injection molding.

The following Table 1 shows an experimental result in regard to the level of the loss of the transmission signal by the tensile force (based on a tensile strength to the optical cable 1 generated when the tensile force is applied to the optical cable 1) using the optical cable lead-in clamp 10 according to the preferred embodiment of the present invention.

The experiment was achieved using testing equipments, such as DFD LD Soure (Agilent, 816624A) , Powermeter (Agilent, 81624B) and Integrity Test System (United, SSM-IOkN) in relative humidity ranging from 51% R.H. to 53% R.H. and in temperature ranging from 23.3^°C to 23.5°C. In addition, as a measuring process, the steps of coupling the optical cable 1 to the clamp 10 before testing the tensile strength, applying an optical signal to the optical cable 1 using DFD LD Soure and Powermeter, and measuring the intensity of radiation were conducted. In addition, a loss change was measured while the tensile strength was increased at intervals of 10kg from the tensile strength of 50kg, and the maximum tensile strength was measured. [Table 1]

As you can see from the [Table 1], when the optical cable 1 is coupled to the clamp 10 according to the present invention, even when the tensile strength of 70kg, where the optical cable 1 is not broken, acts, the optical cable 1 is not separated from the clamp 10, and the clamp 10 was good in the loss change since the loss change was 0.03dB. That is, Korea Telecom (KT) generally demands a clamp, which prevents the separation of the optical cable 1 and has the loss change of about IdB under a tensile strength of about 50kg, but the clamp 10 according to the present invention showed the superior result than the KT's demands. [Mode for Invention]

FIG. 5 is a perspective view showing a modification of the optical cable lead-in clamp of FIG. 1, FIG. 6 is a perspective view showing a state where a nut and additional nut are separated from the optical cable lead-in clamp of FIG. 5 according to the modification, and FIG. 7 is a sectional view showing essential parts of the optical cable lead-in clamp according to the modification.

Referring to FIGS. 5 to 7, the optical cable lead-in clamp 10 according to the modification of the present invention has the same configuration as the preferred embodiment of the present invention, but further includes additional guiding holder 30' additional guiding column 40' and additional nut 60 coupled to the additional guiding column 40 coupled to the rear face 24 of the housing 20, which are formed on the rear face 24 of the housing 20, so that the optical cable 1 can be led into both sides of the housing 20.

In this instance, the additional guiding holder 30 and the additional guiding column 40 respectively have the same structures as the guiding holder 30 and the guiding column 40, and are formed integrally in such a way as to be symmetric to the guiding holder 30 and the guiding column 40 relative to the housing 20. In addition, the additional nut 60 has the same structure as the nut 60, and is coupled to the additional guiding column 40' As described above, the structures and actions of the additional guiding holder 30', the additional guiding column 40' and the additional nut 60 are the same as the guiding holder 30, guiding column 40 and the nut 60, and so, their detailed descriptions will be omitted.

The following Table 2 shows an experimental result in regard to the level of the loss of the transmission signal by the tensile strength using the optical cable lead-in clamp 10 according to the modification of the present invention.

The experiment according to the modification of the present invention was conducted in the same experimental conditions as the preferred embodiment of the present invention. [Table 2]

As you can see from the [Table 2], when the optical cable 1 is coupled to the clamp 10 according to the modification of the present invention, even when the tensile strength of 70kg, where the optical cable 1 is not broken, acts, the optical cable 1 is not separated from the clamp 10, and the clamp 10 was good in the loss change since the loss change was 0.22dB. That is, Korea Telecom (KT) generally demands a clamp, which prevents the separation of the optical cable 1 and has the loss change of about IdB under a tensile strength of about 50kg, but the clamp 10 according to the present invention showed the superior result than the KT¹ s demands.

FIG. 8 is a photograph for explaining a used example of the lead-in cable according to the preferred embodiment of the present invention.

Referring to FIG. 8, the optical cable lead-in clamp 10 according to the preferred embodiment (the illustrated product is the modification of the present invention) has a side anchored to the intermediate clamp 102 coupled to the electric pole or the pole 100 installed in the house by means of the finger stop 90 and the other side for supporting and anchoring the optical cable 1 led in and out.

While the optical cable lead-in clamp according to the present invention has been described with reference to the particular illustrative embodiment, it is not to be restricted by the embodiment but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiment without departing from the scope and spirit of the present invention. [Industrial Applicability]

As described above, the optical cable lead-in clamp according to the present invention can be effectively applied to various cables, to which a tensile force acts, especially, cables, which have a stable anchoring force against the tensile force and minimize the loss of the transmission signal, like the optical cable.

Claims

[CLAIMS] [Claim 1]

An optical cable lead-in clamp for supporting and anchoring an optical cable (1) connected from an electric pole to a house, the optical cable lead- in clamp comprising: a housing (20) having a front face (22), a rear face (24), and a finger stop (90) mounted on a side thereof; a guiding holder (30) mounted on the other side of the housing (20), which is opposed to the side where the finger stop (90) is mounted, the guiding holder (30) protruding forwardly from the front face (22) of the housing (20) and having a guiding surface (32) formed vertically in an arc shape; a guiding column (40) mounted on the housing (20) between the guiding holder (30) and the finger stop (90), the guiding column (40) protruding forwardly from the front face (22) of the housing (20) and having a guiding surface (42) and a screw surface (44) formed in a round shape; and a nut (60) engagedly coupled to the screw surface (44) of the guiding column (40), wherein the optical cable (1) is wound and coupled along the guiding surface (32) of the guiding holder (30) and the guiding surface (42) of the guiding column (40) and led in and out in a direction of the guiding column (40). [Claim 2]

The optical cable lead-in clamp according to claim 1, wherein the screw surface (44) of the guiding column (40) has a thread formed to have a direction in which the nut is fastened to the guiding column (40) when the nut (60) is rotated with respect to a direction in which a tensile force is exerted to the optical cable (1). [Claim 3]

The optical cable lead-in clamp according to claim 1 or 2, further comprising: an additional guiding holder (30') and an additional guiding column (40') respectively formed on the rear face (24) of the housing (20) and having the same structures as those of the guiding holder (30) and the guiding column (40), the additional guiding holder (30') and the additional guiding column (40') being formed symmetrically to the guiding holder (30) and the guiding column (40') relative to the housing (20); and an additional nut (60') having the same structure as that of the nut (60) and coupled to the additional guiding column (40'). [Claim 4]

The optical cable lead-in clamp according to claim 1 or 2, wherein the housing (20), the guiding holder (30) and the guiding column (40) are injection-molded of a plastic material in such a way as to be formed integrally with one another. [Claim 5]

The optical cable lead-in clamp according to claim 1 or 2, wherein the guiding column (40) further includes a stopper (46) extending upwardly from the screw surface (44), and wherein the nut (60) further includes a locking flange (64) caught to the stopper (46) when it is coupled to the guiding column (40). [Claim 6]

An optical cable lead-in clamp for supporting and anchoring an optical cable (1) connected from an electric pole to a house, the optical cable lead- in clamp comprising: a housing (20) having a flat front face (22) and a finger stop (90) mounted on a side thereof; a guiding holder (30) formed integrally with the other side of the housing (20), which is opposed to the side where the finger stop (90) is mounted, the guiding holder (30) protruding forwardly from the front face (22) of the housing (20) and having a guiding surface (32) formed vertically in an arc shape and a guiding flange (34) outwardly extending from the guiding surface (32) at the front end thereof in such a way as to have a guiding space (33) defined between the front face (22) of the housing (20) and the guiding flange (34); a guiding column (40) formed integrally with the housing (20) between the guiding holder (30) and the finger stop (90), the guiding column (40) protruding forwardly from the front face (22) of the housing (20) and having a guiding surface (42) and a screw surface (44) formed in a round shape and a screw surface (44) extending forwardly from the guiding surface (42); and a nut (60) engagedly coupled to the screw surface (44) of the guiding column (40) , wherein the optical cable (1) is wound and coupled along the guiding surface (32) of the guiding holder (30) and the guiding surface (42) of the guiding column (40) and led in and out in a direction of the guiding column (40). [Claim 7]

The optical cable lead-in clamp according to claim 6, wherein the screw surface (44) of the guiding column (40) has a thread formed to have a direction in which the nut is fastened to the guiding column (40) when the nut (60) is rotated with respect to a direction in which a tensile force is exerted to the optical cable (1). [Claim 8]

The optical cable lead-in clamp according to claim 6 or 7, wherein the nut (60) further includes a contact flange (70) having a number of projections (72) projecting from the bottom surface thereof at fixed intervals and located on the outer periphery of the guiding surface (42) of the guiding column (40). [Claim 9]

The optical cable lead-in clamp according to claim 8, wherein the housing (20) further comprises a flat rear face (24) opposed to the front face (22) and formed symmetrically to the front face (22); and an additional guiding holder (30') and an additional guiding column (40') respectively formed on the rear face (24) of the housing (20) and having the same structures as those of the guiding holder (30) and the guiding column (40), the additional guiding holder (30') and the additional guiding column (40') being formed symmetrically to the guiding holder (30) and the guiding column (40) relative to the housing (20); and an additional nut (60') having the same structure as that of the nut (60) and coupled to the additional guiding column (40').