JP3402863B2 - Cable traction device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable pulling device, and more particularly to an endless belt type cable pulling device used for pulling a tip portion or an intermediate portion when aerial installation of an optical fiber cable or the like. Regarding

[0002]

2. Description of the Related Art Conventionally, aerial installation of a cable such as an optical fiber cable has been performed by using a hoisting machine (winch) in addition to manual guidance. In this method, as shown in FIG. 8 (a), the tow rope 2 connected to the tip of the cable 1 is wound by a winch 3 installed on the tip side (front) track or the like, so that the cable This is a method in which the cable 1 delivered from the drum 4 is laid between the electric pole 7 and the like through the bending portion wheel 5 and the pulling wheel 6. In the figure, reference numeral 8 indicates a metal fitting for connecting the cable 1 and the tow rope 2.

In such aerial installation with a winch, along with the lengthening of the cable (1 to 2 km), a tension exceeding the allowable tension (1.5 KN) is applied to the cable by pulling only from the tip side of the cable. In this case, the figure 8 construction method shown below is adopted. In this construction method, as shown in FIG. 8 (b), after the cable 1 fed from a cable drum 4 installed at an intermediate point of laying is wound up by a winch 3 and laid in one direction (direction A), Rewind the remaining cable 9 from the cable drum 4 by hand,
It is a construction method in which the cables 9 which are roughly stacked in the shape of a figure 8 are laid on the ground, and the cables 9 thus stacked are laid in the opposite direction (direction B) by the winch 3 from the winding end side.

Further, as a method of laying a long cable without adopting such an 8-shaped construction method, as shown in FIG. 8C, an endless belt type is installed on each of the pole posts 10 at the laying tip point and the intermediate point. A method of installing a towing machine 11 and pulling the endless belt while gripping the front end portion and the middle portion of the cable 1 and the like is performed.

[0005]

However, these cable laying methods have the following problems.

[0006] That is, in the manual guidance method,
In addition to requiring a large number of people and labor, it is difficult to manage the tension, so that the cable may be pulled by a force exceeding the allowable tension. Also, in the method of pulling the cable 1 from the distal end side with the winch 3 and laying it,
It is difficult to control the traction tension, and there is a dedicated winch that can set the tension, but the setting accuracy is low, so there is a risk that the allowable tension of the cable 1 may be exceeded during work.

Further, in the method of laying a long cable by the figure 8 construction method, the remaining cable 9 laid by pulling in one direction is rewound and stacked in the figure 8 shape.
There was a problem that it required a lot of labor and a large space.

Further, in the method of using the endless belt type tractor 11 to pull the tip end and the middle part of the cable 1, the weight of the endless belt type tractor 11 is large (about 18 kg alone), and The utility pole pedestal 10 for mounting on the utility pole was also heavy (about 20 kg), so the workability of installation and handling was poor. In addition, the conventional endless belt type tractor 11
Is configured to generate a cable gripping force by axial compression of the coil spring, and a coil spring with a large spring constant is used to obtain a sufficient cable gripping force. The part could not be passed through without adjustment. That is, the tow rope 2 (outer diameter
When the connecting part (connecting metal fitting 8) between the cable 1 (outer diameter: 15 to 30 mm) and the cable 1 (outer diameter: 15 to 30 mm) reaches the endless belt type tractor 11, the operation is temporarily stopped and the connecting part is manually pulled by the tractor 11. It was necessary to cause the endless belt type tractor 11 to grip the cable 1 again after proceeding to the end.

The present invention has been made in order to solve these problems. A large pulling force can be obtained with the conventional cable gripping force, and a different diameter portion (outer portion) such as a connecting portion between a cable and a pulling rope is provided. It is an object of the present invention to provide a cable traction device which can continuously pass a diameter variation portion) without adjustment, and which is small and lightweight and easy to handle.

[0010]

In a cable pulling device of the present invention, a plurality of rollers including a drive roller are freely rotatable in a first frame in an arc shape having a radius of curvature equal to or larger than an allowable bending radius of a towed cable. The first cable sending section is provided by winding the driving endless belts around the rollers at both ends, and the driven endless belts at both ends rotatably arranged on the second frame. A second cable sending part arranged at a position opposite to the first cable sending part, and a shaft member inserted substantially parallel to the roller shaft between the rollers at both ends of the second frame. An elongated hole formed in the first frame, into which the shaft member is inserted, and a push-up link that supports both ends of the shaft member,
A pair of urging means for urging the second cable delivery portion toward the first cable delivery portion via the push-up link and the shaft member ; The second cable sending portion approaches and separates from the first cable sending portion in accordance with the size of the towed object that is sandwiched by the second cable sending portion and travels, and the second cable sending portion moves toward and away from the first cable sending portion. It is characterized in that the cable sending unit swings around the shaft member.

[0011]

In the cable pulling device of the present invention, an arcuate gripping portion having a curvature radius greater than the allowable bending radius of the towed cable is formed between the driving endless belt and the driven endless belt. Since the cable is pulled while being gripped, a large pulling force can be secured with the same gripping force as the conventional one, and the pulled cable does not bend beyond the allowable limit.

Further, in the present invention, particularly when the second cable delivery portion is configured to be pressed and biased toward the first cable delivery portion by the elastic force of the torsion coil spring, the gripping diameter of the cable or the like may be increased. Therefore, a constant gripping force can be obtained, and continuous towing work can be performed without adjustment.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing an embodiment of the cable pulling device of the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. 3 is an enlarged cross-sectional view showing the main part of FIG.

In the drawings, reference numeral 12 indicates a first cable feeding portion, which comprises a plurality of upper rollers 14 rotatably supported at one end of a shaft by a main frame 13 and windings at both ends of these rollers. The driven endless belt 15 and a proper tension applied to the endless belt 15 for driving 2
It consists of an individual belt tighter 16 and an upper roller 14
Is composed of one driving roller 17, one driven roller 18 and a plurality of intermediate rollers 19. The upper roller 14 has a driving roller 17 and a driven roller 18 arranged at both ends in an arc shape having a radius of curvature equal to or larger than an allowable bending radius of the cable 20 to be pulled, and a plurality of intermediate rollers 19 are provided therebetween. Are arranged so as to line up in a line, and the endless belt 15 for driving which runs under these rollers has an arc shape with the radius of curvature. Further, the central angle θ of the arc in which the upper rollers 14 are arranged is substantially a right angle (90 °). That is, the drive roller 17 and the driven roller 18 at both ends have two extension lines that extend through the support shafts toward the center of the arc, which is the array line, and are approximately 90 degrees apart.
It is placed in a position on an arc that intersects at an angle of °. Further, a drive motor 21 that rotationally drives the drive roller 17 is provided on the back surface of the main frame 13 (the surface opposite to the mounting surface of the upper roller 14), and the drive shaft thereof can be attached to and detached from the shaft hole portion of the drive roller 17. The handle 21a is attached to the upper portion of the main frame 13.

A second cable sending portion 22 is arranged below the first cable sending portion 12 so as to face it. The second cable delivery portion 22 is guided by two guide rods 23 and is configured to be movable up and down with respect to the main frame 13. The lower frame 24 is rotatably supported at both left and right ends of the lower frame 24. 2 driven rollers 25, 1 idler 26 which is also axially supported in the central portion of the lower frame 24, and a driven endless belt 27 wound around these rollers. Of the driven endless belt 27 so that the upper surface of the driven endless belt 27 traveling above the roller evenly adheres to the arc-shaped lower surface of the driving endless belt 15 when moved (pushed up) to. The length is preset. Note that, as shown in FIG. 4, geta tooth-shaped projections 28 are intermittently formed in the length direction on the roller contact surfaces of the drive endless belt 15 and the driven endless belt 27. However, the driving roller 17 and the driven roller 1
The central portions formed on the main surfaces of the Nos. 8 and 25 mesh with the protruding protrusions to prevent the belt from meandering and coming off. In addition, the drive endless belt 15 (lower traveling surface)
The cable guide 3 is provided on the wire entry side of the cable gripping portion 29 formed by the driven endless belt 27 (upper traveling surface).
0 is detachably installed.

Further, the second cable sending portion 22 as described above is constructed so as to be movable in the vertical direction and is biased upward in the vertical direction. That is, in the second cable sending portion 22, as shown in an enlarged view in FIG. 3, both ends of the idler shaft 32, to which the idler 26 is attached via the bearing 31, are attached to the lower frame 24 and the push-up link, respectively. It passes through 33 in order and is swingably supported by the main frame 13. That is, the bushes 34 with flanges are fitted around the outer circumferences of both ends of the idler shaft 32, and are positioned and fixed by the retaining ring 35. The idler shaft 32 with the bushes 34 fitted therein is
The main frame 13 is inserted into the long holes 36 having the same width as the outer diameter of the flanged bushes 34 provided on both front and back surfaces of the main frame 13. Further, both ends of the idler shaft 32 have the long holes 3
The lower frame 24, through which the idler shaft 32 penetrates, moves in the vertical direction along the elongated hole 36 as it moves in the position 6, and swings up and down about the idler shaft 32.

A support shaft 38 having a vertical guide shaft 37 vertically attached to the central portion is provided under the push-up link 33.
Is inserted in parallel with the idler shaft 32. Further, below the support shaft 38, two spring bearing pins 40, each of which has a cylindrical collar 39 rotatably fitted on the outer periphery thereof, are arranged in parallel with the support shaft 38, and at the lower end of the push-up link 33. It is attached through this. Furthermore,
Two spring guides 41 having a diameter slightly smaller than the coil inner diameter of a torsion coil spring, which will be described later, are arranged in the vicinity of these spring bearing pins 40 so as to face each other in parallel with the spring bearing pins 40, and both end portions thereof are arranged. Are supported and fixed to the main frame 13. Further, two torsion coil springs 42 are arranged outside the spring guides 41, and these torsion coil springs 42 are engaged at one end thereof with a fixing pin 43 which is fixed by being inserted into the main frame 13. It is stopped, and the opposite end is assembled in a cylindrical collar 39 fitted on the outer circumference of the spring receiving pin 40 in a state in which the necessary amount is displaced in advance. Then, the vertically upward elastic force generated by the displacement of the torsion coil spring 42 passes through the push-up link 33 and the idler shaft 32 in order, and then the lower frame 24.
The second cable sending portion 22 is always urged upward.

Furthermore, in the lower part of the vertical guide shaft 37,
A screw shaft 45 having a thread formed on the outer peripheral surface and a handle 44 fixed to the lower end is integrally provided.
The screw thread is screwed into a screw groove formed on the inner peripheral surface of the lower cylindrical portion 46 of the main frame 13. Then, by turning the handle 44 and lowering the screw shaft 45, the second cable sending portion 22 is moved downward along the main frame 13 so that the driving endless belt 15 and the driven endless belt 27 hold the cable. It is configured to open.
That is, by turning the handle, the screw shaft 45 and the vertical guide shaft 37 integrated with the screw shaft 45 are moved downward, and the push-up link 33 is pushed down via the support shaft 38.
The entire lower frame 24 and the second cable delivery portion 22 are moved downward to expand the cable gripping portion 29 formed by the driving endless belt 15 and the driven endless belt 27 to release the gripping of the cable. It has become.

The cable pulling device of the embodiment thus constructed is used as a tip or an intermediate pulling device when a cable such as an optical fiber cable is laid overhead, by attaching it to the ground of the power pole using a power pole stand or the like. To be done.

In the cable pulling device of this embodiment, the driving roller 17, the driven roller 18, and the intermediate roller 19 are arranged in an arc shape having a curvature radius larger than the allowable bending radius of the cable 20, and the driving endless belt. Since the cable gripping portion 29 formed by the endless belt 15 and the driven endless belt 27 has an arcuate shape, it has a larger friction with the same gripping force as compared with the conventional traction device having a linear cable gripping portion. A force (traction force) is obtained, and in particular, in the embodiment in which the angle θ at which the extension lines at both ends of the cable gripping portion 29 intersect, which is the central angle of the circular arc, is about 90 °, the same gripping force causes more than double friction. Power is gained.

That is, in the belt type traction device having the linear cable gripping portion shown in FIG. 5 (a), the maximum frictional force (maximum traction force) F is F = μW ... (1)
In the cable pulling device of this embodiment having the arc-shaped cable gripping portion shown in FIG. 5B, F = μWe ^μθ.
(2)

However, F: maximum frictional force (traction force) W: gripping force μ: friction coefficient between the cable and the traction belt is about 0.5 θ in actual measurement value: intersection angle (rad) e: base of natural logarithm (2.718 ...) In equation (2), e ^{μ θ} is the coefficient of frictional force increase and μ
= 0.5 and θ = 90 °, e ^μθ = 2.2, and the cable traction device of the embodiment is ^{similar to} the conventional linear traction device.
It will show 2.2 times the frictional force (traction force).

Further, in the cable pulling device of the embodiment, pulling is performed by the vertical movement and swing mechanism of the lower frame 24 (second cable sending portion 22) and the vertically upward pressing biasing mechanism by the torsion coil spring 42. It is possible to pass a different-diameter portion from a small diameter to a large diameter, such as a connecting portion between a rope and a cable, while keeping the gripping force almost constant. This is because although the displacement of the torsion coil spring 42 increases and the twisting moment increases as the gripping diameter increases, the vertical component force of the twisting moment corresponding to the cable gripping force hardly changes and the initial value is This is because they are almost the same.

The relationship between the gripping stroke (corresponding to the gripping diameter) and the gripping force in the torsion coil spring is concretely shown below.

FIG. 6 shows a mounting design example of the torsion coil spring used in this embodiment.

In the figure, d (strand diameter) = 6 mm D (roll diameter) = 50 mm N (effective number of windings) = 8 rolls a ₁ = 40 mm a ₂ = 25 mm a ₃ = 46.5 mm s (stroke) = 35 mm (MAX ) Θ (increased displacement angle) = 45 ° (MAX) θ _s (initial displacement angle) = 77 ° (MAX).

When the relationship between the gripping stroke and the gripping force in such a torsion coil spring was obtained, the graph shown in FIG. 7 was obtained, and it was confirmed that the gripping force hardly changes even if the gripping stroke increases. .

[0029]

As described above, according to the cable pulling device of the present invention, a cable such as an optical fiber cable can be pulled by applying a large frictional pulling force, and the connecting portion between the pulling rope and the cable can be pulled. It is possible to continuously pass such an outer diameter changing portion as described above without adjusting the gripping force. Further, since it is small and lightweight and easy to install and handle, it is suitable as a tip or intermediate traction device for aerial installation.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a cable pulling device of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

3 is a cross-sectional view showing an enlarged main part in FIG.

FIG. 4 is a perspective view showing the shape of protrusions on the roller contact surfaces of the driving endless belt and the driven endless belt used in the embodiment;

5A and 5B are views for explaining the relationship between the maximum frictional force and the gripping force in the cable pulling device, FIG. 5A is a diagram schematically showing a conventional pulling device having a linear grip portion, and FIG.
FIG. 3 is a diagram schematically showing a traction device having an arcuate grip portion of the embodiment.

FIG. 6 is a front view showing a mounting design example of the torsion coil spring used in the embodiment.

7 is a graph showing a relationship between a grip stroke and a grip force in the torsion coil spring shown in FIG.

FIG. 8 is a diagram schematically showing a conventional cable towing and aerial installation method.

[Explanation of symbols]

12 ... The first cable sending unit 13 ... Main frame 15 ... Endless belt for driving 16 ... Belt belt toner 17 ......... Drive roller 18, 25 ......... Driven roller 20 ……… Cable 22 ... The second cable sending section 24 ………… Lower frame 25 ......... Lower driven roller 26 ………… idler 27 ………… Endless belt for driven 32 ………… idler shaft 33 ......... Press up link 36 ......... long hole 37 ... Vertical guide shaft 40 ………… Spring bearing pin 42 ... torsion coil spring 44 ......... Handle

─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Ayu Aida 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation (72) Hiroshi Hosoda 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 1 Showa Densen Denki Co., Ltd. (72) Inventor Seiichiro Sano 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture (56) Showa Densen Denki Co., Ltd. (56) Reference JP-A-50-69591 ) JP-A-61-282265 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 6/00-6/54 B65H 51/00-51/32

Claims (3)

(57) [Claims] 1. A plurality of rollers including a driving roller are arranged in a first frame so as to be rotatable in an arc shape having a radius of curvature equal to or larger than an allowable bending radius of a towed cable, and endless rollers for driving are provided on the rollers at both ends thereof. A first cable sending portion formed by winding a belt and endless belts for driving driven rollers at both ends rotatably arranged on a second frame are wound around the first cable sending portion at a position opposite to the first cable sending portion. A second cable sending portion arranged; a shaft member inserted in parallel to a roller shaft at a substantially central portion between the rollers at both ends of the second frame; and a shaft member formed on the first frame, The elongated cable through which a member is inserted, a push-up link that supports both end portions of the shaft member, and the second cable delivery unit that connects the second cable delivery unit to the first cable delivery unit via the push-up link and the shaft member. One that pushes and urges to the side Urging means, the second cable sending portion being the first cable sending portion depending on the size of the towed object that is sandwiched between the first cable sending portion and the second cable sending portion and travels. A cable pulling device characterized in that the second cable feeding portion swings around the shaft member while approaching and separating from the cable feeding portion. 2. The angle of intersection of two straight lines that are orthogonal to the support shafts of the rollers at both ends of the first cable delivery portion and that pass through the center of the arc is about 90 °. Cable traction device as described. 3. The cable traction device according to claim 1, wherein the urging means is a torsion coil spring.