Fixing tool and fixing method

Abstract

A fixing tool 1 for temporarily fixing a cable to a groove, the tool including: an elastic body 11 of an arbitrary length; a first contact part 12a provided at one end of the elastic body; a second contact part 12b provided at the other end of the elastic body; and a draw part 13 having one end attached to one end of the elastic body or the first contact part and the other end attached to the other end of the elastic body or the second contact part.

Description

Fixtures and fixing methods

[0001] The present disclosure relates to a fastener and a fastening method.

[0002] There are techniques for laying optical cables on the ground. For example, a trench is dug in the ground and an optical cable is laid in the trench (see Patent Document 1 and Non-Patent Document 1). A mat is laid on the ground, a trench is dug in the mat, and an optical cable is laid in the trench (see Non-Patent Document 1). An installer places the optical cable in such a trench, pours in a repair material, and lays the optical cable by allowing the repair material to harden.

[0003] Japanese Unexamined Patent Publication No. 63-55204

[0004] Makoto Sakurai and six others, "Study on Improving the Installation Efficiency of Optical Fiber Cables for Road Surface Wiring," Institute of Electronics, Information and Communication Engineers General Conference, 2023, B-13-12, p.264

[0005] However, because it takes time for the repair material to harden, if the optical cable is twisted, the optical cable may pop out of the groove before the repair material hardens. Furthermore, if part of the groove width is narrower than the diameter of the optical cable, or if the groove width is the same as the diameter of the optical cable, it becomes difficult to lay the optical cable in the groove ideally. Part of the optical cable may get caught in the groove, causing the optical cable to pop out of the groove. This can cause installers or passersby to trip over the protruding optical cable, potentially compromising the safety of the optical cable installation work.

[0006] The present disclosure has been made in consideration of the above circumstances, and an object of the present disclosure is to provide a technology that can improve the work of laying optical cables.

[0007] A fixing device according to one embodiment of the present disclosure is a fixing device for temporarily fixing a cable in a groove, and includes an elastic body of any length, a first contact portion provided at one end of the elastic body, a second contact portion provided at the other end of the elastic body, and a pull-out portion having one end attached to one end of the elastic body or the first contact portion and the other end attached to the other end of the elastic body or the second contact portion.

[0008] A fixing method according to one aspect of the present disclosure is a fixing method for fixing a cable in a groove, in which the cable is placed in the groove and temporarily fixed in the groove with a fixture comprising an elastic body of any length, a first contact portion at one end of the elastic body, a second contact portion at the other end of the elastic body, and a pull-out portion having one end attached to one end of the elastic body or the first contact portion and the other end attached to the other end of the elastic body or the second contact portion, a repair material is placed in the groove, and after the repair material has set, the fixture is removed from the groove.

[0009] According to the present disclosure, a technique that can improve the work of laying optical cables can be provided.

[0010] FIG. 1 is a diagram showing an example of the configuration of an optical cable fixture according to this embodiment. FIG. 2 is a diagram showing a method for fixing the fixture in a groove. FIG. 3 is a diagram showing a method for removing the fixture from the groove. FIG. 4A is a diagram showing a method for laying an optical cable in a groove. FIG. 4B is a diagram showing a method for laying an optical cable in a groove. FIG. 5 is a reference diagram for explaining the characteristics of the fixture relative to the groove width. FIG. 6 is a diagram showing an example of the configuration of a fixture realized by a leaf spring. FIG. 7 is a diagram showing a method for fixing a fixture realized by a leaf spring in a groove. FIG. 8 is a diagram showing a method for removing a fixture realized by a leaf spring from a groove. FIG. 9 is a reference diagram for explaining the characteristics of the width between both ends of the leaf spring.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same parts are designated by the same reference numerals and the description thereof will be omitted.

[0012] [Summary of the Disclosure] The disclosure discloses a technology for temporarily fixing an optical cable in a trench when laying the optical cable in the trench. Specifically, the disclosure discloses a fixture for temporarily fixing an optical cable in the trench and a method for temporarily fixing and fixing the optical cable in the trench using the fixture. By temporarily fixing the optical cable in the trench with the fixture until the repair material hardens, it is possible to prevent the optical cable from protruding, ensuring safe and secure optical cable laying work.

[0013] [Configuration Example of Optical Cable Fixture] FIG. 1 is a diagram showing a configuration example of an optical cable fixture 1 according to this embodiment.

[0014] The fixture 1 is a jig for temporarily fixing the optical cable in the groove. That is, the fixture 1 is used to prevent the optical cable from jumping out (protruding) from the inside of the groove when the optical cable is laid in the groove.

[0015] The fixing device 1 includes an elastic body 11 , a first contact portion 12 a , a second contact portion 12 b , and a pull-out portion 13 .

[0016] The elastic body 11 is a structure of any length that can expand and contract in the horizontal direction of the paper (its own longitudinal direction), and has the structure and function of being able to contract to a width equal to or less than the groove width of a groove formed in the road surface and expand to a width greater than the groove width. For example, the elastic body 11 has the function of a spring, and can be contracted to a width equal to or less than the groove width before being inserted into the groove, and can be expanded to the groove width after being inserted.

[0017] The first contact portion 12a is provided at one end of the elastic body 11 and has a plate-like shape that is approximately perpendicular to the longitudinal direction of the elastic body 11. The second contact portion 12b is provided at the other end of the elastic body 11 and has a plate-like shape that is approximately perpendicular to the longitudinal direction of the elastic body 11. After being inserted into the groove, the first contact portion 12a and the second contact portion 12b are pressed by the restoring force of the elastic body 11 and come into contact with and press against two opposing side surfaces in the groove.

[0018] Pull-out portion 13 is used to pull fastener 1 out of the groove, and has one end attached to first contact portion 12 a and the other end attached to second contact portion 12 b. Pull-out portion 13 is, for example, a piano wire or a rope, and when pulled in the direction to come out of the groove, applies force to elastic body 11 in the direction that causes elastic body 11 to contract.

[0019] [Method of Fixing Fixture] FIG. 2 is a diagram showing a method of fixing fixture 1 in a groove.

[0020] After the optical cable 3 is installed in the groove 100 on the road 2, pressure is applied from the outside to the first contact portion 12a and the second contact portion 12b to reduce the width (longitudinal length) of the elastic body 11, and the fixing device 1 with its overall width (length) reduced is inserted into the groove 100 and installed at a position above the optical cable 3.

[0021] When the external pressure is released, the elastic body 11 gradually widens due to its own restoring force, and the first contact portion 12a and the second contact portion 12b are pressed outward by the restoring force, contacting the two opposing side surfaces 100a, 100b in the groove 100 and pressing against the two opposing side surfaces 100a, 100b.

[0022] In this way, the first contact portion 12a and the second contact portion 12b press against the two opposing side surfaces 100a, 100b in the groove 100, generating a frictional force between the fixture 1 and the two opposing side surfaces 100a, 100b, thereby preventing the optical cable 3 located below the fixture 1 from jumping out of the groove 100.

[0023] [Method of Pulling Out Fixture] FIG. 3 is a diagram showing a method of pulling out fixture 1 from the groove.

[0024] Pull-out portion 13 is pulled up in the direction of coming out of groove 100. When pull-out portion 13 is pulled up, the force F presses both ends of elastic body 11 inward, and a force Fx acts in the direction of contracting elastic body 11, allowing fastener 1 to be easily pulled out from groove 100. Because fastener 1 can be easily pulled out, the asphalt of road 2 with which fastener 1 is in contact will not be destroyed.

[0025] Furthermore, even if the optical cable 3 is lifted by twisting and a force is applied from below in a direction pushing up the fixing device 1, the force applied is near the center of the longitudinal direction of the elastic body 11, so no force Fx acts in the direction of contraction on the elastic body 11, and the fixing strength of the fixing device 1 does not decrease.

[0026] [Method of Laying Optical Cable] FIGS. 4A and 4B are diagrams showing a method of laying the optical cable 3 in the groove 100. FIG.

[0027] A trench 100 is dug in a road 2, and an optical cable 3 is placed in the trench 100 (step S1).

[0028] Next, the fixture 1 is inserted into the groove 100 and fixed at a position above the optical cable 3 (step S2). This reduces the possibility that the optical cable 3 will jump out of the groove 100.

[0029] Next, the groove 100 is filled with the first repair material 4 (step S3). As shown in the top view of the upper side below step S2, there are gaps 200 between the multiple fasteners 1. The first repair material 4 is poured into the groove 100 through the gaps 200.

[0030] In this way, the presence of the fixing device 1 prevents the optical cable 3 from protruding from the groove 100. Furthermore, because of the presence of the gap 200, even if the optical cable 3 protrudes from the first repair material 4, the state can be confirmed through the gap 200 and appropriate measures can be taken. Even if the optical cable 3 protrudes from the gap 200, the optical cable 3 can be pushed back into the groove 100 using some kind of tool or jig. Thereafter, the first repair material 4 hardens over time, and the optical cable 3 is fixed in the groove 100.

[0031] Next, after the first repair material 4 has hardened, the fixing device 1 is removed from the groove 100 (step S4). When removing the fixing device 1, for example, the pull-out portion 13 is grasped with a tool such as pliers and pulled out while being wrapped around the tool. By wrapping the pull-out portion 13 around the tool and pulling out the fixing device 1, the restoring force of the elastic body 11 can be limited, and the elastic body 11 can be prevented from popping out.

[0032] Finally, the second repair material 5 is poured into the groove 100 (step S5). This eliminates any difference in level with the road 2, and the groove 100 is integrated with the road 2.

[0033] [Characteristics of Fixture 1 with Respect to Groove Width] The diameter of an optical cable varies depending on the number of optical fibers in the optical cable. As the number of optical fibers increases, the diameter of the optical cable increases. The groove width is determined according to the diameter of the optical cable, so the groove width is not constant. Therefore, when temporarily fixing an optical cable with fixture 1, it is necessary to be independent of the groove width.

[0034] In this regard, the elastic body 11 of the fixing device 1 has an elastic structure and elastic function, so it can flexibly accommodate changes in groove width. In other words, because the longitudinal length can be adjusted, one elastic body 11 can accommodate grooves of a certain width, whether the groove width is wide or narrow. As shown in Figure 5(a), it can also accommodate a groove 100 with a large groove width for laying an optical cable 3 with a large diameter. As shown in Figure 5(b), it can also accommodate a groove 100 with a small groove width for laying an optical cable 3 with a small diameter.

[0035] [Embodiment of Fixture] The fixture 1 can be realized by, for example, a leaf spring. A leaf spring is, for example, a single metal plate that is pressed from both ends and has an elastic function inside.

[0036] 6 is a diagram showing an example of the configuration of fixture 1 realized with a leaf spring. In this fixture 1, elastic body 11, first contact portion 12a, and second contact portion 12b are made of leaf springs. Pull-out portion 13 is made of a material such as piano wire, which has excellent flexibility and tensile strength.

[0037] FIG. 7 shows a method of fixing the fixture 1 in the groove using a leaf spring.

[0038] After placing the optical cable 3 in a groove 100 on the road 2, pressure is applied from the outside to both ends (12a, 12b) of the leaf spring to reduce the width (horizontal length on the paper) of the spring portion (11) of the leaf spring, and the leaf spring (1) is inserted into the groove 100 with the spring portion (11) facing downward and placed at a position above the optical cable 3. At this time, pressing the convex portions of the spring portion (11) from both the left and right narrows its width, making it easier to insert.

[0039] When the external pressure is released, the spring portion (11) gradually widens due to its own restoring force, and both ends (12a, 12b) are pressed outward by the restoring force, coming into contact with the two opposing side surfaces 100a, 100b of the groove 100 and pressing against the two opposing side surfaces 100a, 100b.

[0040] In this way, both ends (12a, 12b) press against the two opposing side surfaces 100a, 100b in the groove 100, so that a frictional force is generated between the fixing device 1 and the two opposing side surfaces 100a, 100b, and the optical cable 3 located below the leaf spring (1) can be prevented from jumping out of the groove 100.

[0041] FIG. 8 is a diagram showing a method for removing the fixing device 1 realized by the leaf spring from the groove.

[0042] The piano wire (13) is pulled up in the direction coming out of the groove 100. When the piano wire (13) is pulled up, it takes on an upward convex shape and an upward force F is applied. This upward force F causes a component of force Fx perpendicular to the depth direction of the groove 100 to act in a direction that compresses the spring portion (11), weakening the fixing strength of the fixing device 1 and allowing the fixing device 1 to be easily pulled out of the groove 100. Because the fixing device 1 can be easily pulled out, the asphalt of the road 2 with which the fixing device 1 was in contact will not be damaged.

[0043] Furthermore, even if the optical cable 3 is lifted by twisting and a force is applied from below in a direction pushing up the leaf spring (1), the center of the spring part (11) is pushed up, which acts in a direction to widen the spring part (11), thereby strengthening the fixing strength of the fixing device 1.

[0044] [Characteristics of the Width Between Both Ends of the Leaf Spring] Figures 6 to 8 show an example in which the overall shape of both ends (12a, 12b) of the leaf spring in its natural state is upwardly convex (triangle-shaped). However, as shown in Figure 9, the overall shape of both ends (12a, 12b) may be downwardly convex (▽-shaped). This makes it easier to insert the leaf spring (1) into the groove 100.

[0045] In particular, it is preferable that the width W1 between the tips of both ends (12a, 12b) of the leaf spring on the groove insertion side is narrower than the maximum width W2 of the fixture 1. It is even more preferable that the width W1 between the tips is narrower than the width W3 of the groove 100.

[0046] [Others] The groove 100 is, for example, a groove formed in the ground or a groove formed in a mat on the ground, but it may be any groove for laying the optical cable 3 .

[0047] The optical cable 3 is an example of a cable. The fixture 1 of this embodiment can also be used when temporarily fixing various cables, such as electric cables, in the groove 100.

[0048] The pull-out portion 13 may have one end attached to one end of the elastic body 11 and the other end attached to the other end of the elastic body 11. The pull-out portion 13 may have one end attached to one end of the elastic body 11 and the other end attached to the first contact portion 12a or the second contact portion 12b provided at the other end of the elastic body 11.

[0049] [Effect] According to this embodiment, the fixing device 1 for temporarily fixing the optical cable 3 in the groove 100 comprises an elastic body 11 of any length, a first contact portion 12a provided at one end of the elastic body 11, a second contact portion 12b provided at the other end of the elastic body 11, and a pull-out portion 13 having one end attached to the first contact portion 12a and the other end attached to the second contact portion 12b. Therefore, by applying the fixing device 1 to the groove 100, the optical cable 3 can be prevented from jumping out of the groove 100, and safe optical cable installation work can be achieved.

[0050] REFERENCE SIGNS LIST 1 Fixing tool 11 Elastic body 12a First contact portion 12b Second contact portion 13 Pull-out portion 2 Road 3 Optical cable 4 First repair material 5 Second repair material 100 Groove 100a, 100b Two opposing side surfaces 200 Gap

Claims

1. A fixture for temporarily fixing a cable in a groove, comprising: an elastomer of arbitrary length; a first contact portion provided at one end of the elastomer; a second contact portion provided at the other end of the elastomer; and a pulling portion having one end attached to one end of the elastomer or the first contact portion and the other end attached to the other end of the elastomer or the second contact portion.

2. The fixture according to claim 1, wherein the elastomer shrinks to a width less than or equal to the width of the groove and extends to a width greater than or equal to the width of the groove, the first contact portion and the second contact portion press against opposite side surfaces of the groove by the restoring force of the elastomer, and the pulling portion applies a force to the elastomer in a direction in which the elastomer shrinks when pulled in a direction out of the groove.

3. The fixture according to claim 1, wherein the length between the end on the groove insertion side of the first contact portion and the end on the groove insertion side of the second contact portion is shorter than the maximum length of the fixture.

4. A fixing method for fixing a cable in a groove, comprising: inserting a cable into the groove; using a fixture comprising an elastomer of arbitrary length, a first contact portion provided at one end of the elastomer, a second contact portion provided at the other end of the elastomer, and a pulling portion having one end attached to one end of the elastomer or the first contact portion and the other end attached to the other end of the elastomer or the second contact portion to temporarily fix the cable in the groove; inserting a repair material into the groove; and removing the fixture from the groove after the repair material is fixed.

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