JP4902600B2 - Auxiliary tube for optical fiber cable - Google Patents

Description

  The present invention relates to an outer gripping member of an existing connector for an optical fiber cable, as the optical fiber cable used for in-house wiring and existing condominium wiring is made thinner to reduce the outer dimension. It is related with the auxiliary tube used when installing in.

  In recent FTTH (Fiber To The Home), on-site connectors have been developed and are widely used so that connectors can be attached to optical fiber cables drawn into homes or existing condominiums. The field-attached connector has an optical fiber connection component with a device, a holding mechanism for holding and fixing the outer cover gripping member, and the outer cover gripping member. A holding mechanism that holds and fixes the outer gripping member is built in, and the outer gripping member that holds the optical fiber cable is stored in the holding mechanism that holds and fixes the outer gripping member of the on-site connector body. A connector is attached.

  When drawing into a house or an existing condominium, etc., there are already many cables in the wiring route, and there are small gaps (spaces) where additional wiring is possible, and it may be difficult to route with conventional optical fiber cable outlines. ing. Therefore, if the wiring is facilitated by using a thin optical fiber cable having a smaller external dimension, it cannot be attached to the outer gripping member of the on-site connector set with the conventional optical fiber cable. In order to solve this problem, by passing an auxiliary tube as an adapter through a thinned optical fiber cable, the outer shape of the portion to be attached to the jacket gripping member can be made substantially the same, and a field-installed connector can be attached in the same manner as before. Is.

  In addition, the handleability of the cable after attaching the on-site connector is also an auxiliary tube that is configured and set so that the gripping force of the outer gripping member of the optical fiber cable is generally 1 kg or more as in the conventional case.

  By the way, Patent Document 1 discloses a technique for gripping and fixing a wire harness using a pressing member formed with a tapered portion. In this system, the wire harness is gripped by the taper portion of the pressing member regardless of the outer diameter of the wire harness, and damage to the connector and the solder connection portion in the housing is prevented. However, in this method, in the case of an optical fiber cable, it is assumed that when tension is applied, excessive side pressure is applied to the side surface of the optical fiber cable due to the taper, or the gripping position moves due to the tapered structure. It may cause a loss abnormality.

Therefore, the configuration described in Patent Document 1 cannot be applied to an optical fiber cable as it is.
Japanese Patent Application No. 2002-183206

  Therefore, in the present invention, as a structure having a holding and fixing function in which excessive side pressure is not applied and the holding position does not move, a general jacket holding member applied in the outer shape of an existing optical fiber cable The conventional field-attached connector can be easily used even with an optical fiber cable that has been reduced in thickness so that the gripping force is, for example, 1 kg or more without applying excessive side pressure to the optical fiber cable that has been reduced in diameter. There is a need.

  The present invention enables an optical fiber cable that is thinner than before to be easily pulled into a house or an existing condominium, etc. It is an object of the present invention to be able to maintain the alignment of the outer shape and the proper gripping force so that an optical fiber cable that is thinner than before can be attached.

The present invention is an annular optical fiber cable auxiliary tube for installing an optical fiber cable on a jacket holding member,
The auxiliary tube is formed in a direction intersecting the first peripheral surface with a first peripheral wall having a first opposing surface that contacts the optical fiber cable when the optical fiber cable is inserted; A second peripheral wall having a second facing surface in which a gap is formed between the optical fiber cable and
An optical fiber configured such that when the auxiliary tube into which the optical fiber cable is inserted is installed on the jacket holding member, the second facing surface is deformed inward to contact the optical fiber cable. This is an auxiliary tube for cables.

In the auxiliary tube for optical fiber cable,
It is an auxiliary tube for an optical fiber cable in which a protrusion is provided on the outer surface of the second peripheral wall .

  Further, in the auxiliary tube for an optical fiber cable, the thickness of the first peripheral wall is larger than that of the second peripheral wall.

  INDUSTRIAL APPLICABILITY The present invention uses an auxiliary tube for an optical fiber cable to an optical fiber cable that has been made thinner with a smaller outer dimension than before, and is easily drawn into a house or an existing apartment, etc. The on-site connector can be used as it is.

  FIG. 1 is a sectional view showing a schematic configuration of an optical fiber cable auxiliary tube 1 according to an embodiment of the present invention, and FIG. 2 is a schematic installation state of the optical fiber cable auxiliary tube 1 according to an embodiment of the present invention. FIG.

  As shown in FIGS. 1 and 2, the auxiliary tube 1 for an optical fiber cable having a substantially rectangular cross section and an annular shape is provided with an optical fiber cable 3 having a rectangular cross section, which is thinned by making the outer dimensions smaller than before. When inserted, the optical fiber cable 3 is provided with a first facing surface 7 whose inner surface contacts, and a first peripheral wall 13 provided with the first facing surface 7 of the auxiliary tube 1 is provided.

  Moreover, it is provided with a second facing surface 9 formed in a direction intersecting with the first facing surface 7, and has a second peripheral wall 15 provided with the second facing surface 9 of the auxiliary tube 1. The shape is substantially rectangular. The first peripheral wall 13 is thicker than the second peripheral wall 15. In other words, the second peripheral wall 15 is formed thinner than the first peripheral wall 13 so as to be more easily elastically deformed than the first peripheral wall 13.

  The auxiliary tube 1 includes the first and second peripheral walls 13 and 15 so that the inner peripheral surface is formed in an annular shape (for example, a rectangular annular shape corresponding to the outer shape of the optical fiber cable 3). When the optical fiber cable 3 having a rectangular cross section is inserted into the auxiliary tube 1 having the above configuration, the first facing surface 7 contacts the side surface of the optical fiber cable 3 so that the optical fiber cable 3 is held and positioned. It is like that. That is, in FIG. 1, the movement in the left-right direction is restricted so that the optical fiber core wire 5 provided in the optical fiber cable 3 is positioned at the center in the left-right direction. A gap 17 is formed between the second facing surface 9 and the optical fiber cable 3. The insertion property of the optical fiber cable 3 into the auxiliary tube 1 is such that a gap 17 is formed between the second facing surface 9 and the optical fiber cable 3, so that the first facing surface 7. In addition, the configuration is such that the optical fiber cable 3 can be easily inserted into the auxiliary tube 1 by reducing the contact surface and reducing the frictional force as compared with the configuration in which both surfaces of the second facing surface 9 are in contact with each other. The auxiliary tube is made of a flame retardant olefin resin.

  By the way, when the auxiliary tube 1 is installed on an existing general jacket holding member 19 with the auxiliary tube 1 attached to the end of the thin optical fiber cable 3, as shown in FIG. The facing surface 9 is elastically deformed inward so as to contact the optical fiber cable 3 from both sides. That is, the protrusion 11 that is pressed by the main body frame 19 a of the outer covering member 19 is provided on the outer surface of the second peripheral wall 15. Further, since the second peripheral wall 15 is thin, it is configured to be easily elastically deformed inward. The protrusion 11 is provided at the center of the second peripheral wall 15 of the auxiliary tube 1, and the shape of the protrusion 11 is an isosceles trapezoid when viewed in a cross section perpendicular to the longitudinal direction of the auxiliary tube 1. ing. And it becomes the structure which followed in the longitudinal direction. Note that a plurality of the protrusions 11 may be arranged in parallel, or may be discontinuous. The auxiliary tube 1 may be made of the same resin as the jacket of the optical fiber cable 3.

  When installed on the jacket gripping member 19, the auxiliary tube 1 into which the optical fiber cable 3 is inserted is inserted into the body frame 19 a of the jacket gripping member 19 as shown in FIGS. 3 (a) and 3 (b). The second peripheral wall 15 is elastically deformed inward by being pushed so that 13 is preceded, and each of the projection 11, the first opposing surface 7, and the second opposing surface 9 of the auxiliary tube 1 is deformed. Since stress concentration occurs at the intersecting portion or the portion where the straight line connecting the upper and lower bases of the projection 11 having the isosceles trapezoidal shape intersects the outer periphery, the installation is performed by chamfering the intersecting portion in an arc shape or the like. Sometimes it is possible to prevent the auxiliary tube 1 from tearing at the intersection.

  As described above, when the optical fiber cable 3 is installed on the jacket holding member 19, the protrusion 11 of the auxiliary tube 1 is pressed, and the second facing surface 9 comes into contact with and presses the optical fiber cable 3 from both the upper and lower sides. The optical fiber core wire 5 is positioned at the center in the vertical direction.

  By using the auxiliary tube 1 for an optical fiber cable according to the present embodiment, the optical fiber cable 3 that is made thin like the conventional optical fiber cable 3 can be used as it is for an existing field connector. At the same time, it is also attached to a conventional optical fiber cable as usual, and can be used properly depending on the conditions of the construction environment.

  By the way, the present invention is not limited to the embodiment as described above, and can be implemented in other modes by making appropriate modifications. That is, the gap 17 between the auxiliary tube 1 and the optical fiber cable 3 is configured to be generated on the long side of the rectangular shape, but may be configured to be generated on the short side. It is also possible to form a holding groove for holding the optical fiber cable 3 on the first facing surface 7 of the auxiliary tube 1. That is, various changes are possible.

It is sectional drawing which shows schematic structure of the auxiliary tube for optical fiber cables. It is a perspective view which shows the general installation state of the auxiliary tube for optical fiber cables which concerns on embodiment of this invention. It is sectional drawing which shows an auxiliary tube deformation | transformation state at the time of installing in a jacket holding member in the state which inserted the optical fiber cable in the auxiliary tube for optical fiber cables.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Auxiliary tube for optical fiber cables 3 ... Optical fiber cable 5 ... Optical fiber core wire 7 ... 1st opposing surface (regulation surface)
DESCRIPTION OF SYMBOLS 9 ... 2nd opposing surface 11 ... Protrusion 13 ... 1st opposing wall part 15 ... 2nd opposing wall part 17 ... Space | gap 19 ... Outer gripping member 19a ...・ Body frame 19b ・ ・ ・ Lid

Claims (3)

An auxiliary tube for an annular optical fiber cable for installing the optical fiber cable on the jacket holding member,
The auxiliary tube is formed in a direction intersecting the first peripheral surface with a first peripheral wall having a first opposing surface that contacts the optical fiber cable when the optical fiber cable is inserted; A second peripheral wall having a second facing surface in which a gap is formed between the optical fiber cable and
When the auxiliary tube into which the optical fiber cable is inserted is installed on the jacket holding member, the second facing surface is configured to be deformed inward so as to contact the optical fiber cable. Auxiliary tube for optical fiber cable. In the auxiliary tube for optical fiber cables according to claim 1,
An auxiliary tube for an optical fiber cable, wherein a protrusion is provided on the outer surface of the second peripheral wall .   The auxiliary tube for an optical fiber cable according to claim 1 or 2, wherein the thickness of the first peripheral wall is thicker than that of the second peripheral wall. .

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