JPH07177629A - Cable pulling apparatus - Google Patents

Abstract

PURPOSE:To ensure required hauling power by employing an endless inner belt being driven together with a hauling belt while fitting the outer peripheral face thereof tightly to the hauling belt at a part where the hauling belt touches a cable. CONSTITUTION:When a driving wheel 4 is driven, a hauling belt 2 begins to rotate in the direction of an arrow 15 and a cable 1 held between a pair of hauling belts 2 is pulled in the direction of an arrow 16. At that time, an inner belt 7 fitted tightly, by a predetermined length, to the inner peripheral face 2B of the hauling belt 2 begins to rotate together with the hauling belt 2. The inner belt 7 is a conventional belt having flat face and pressed, with constant force at a relatively short pitch, against the hauling belt 2 by means of an inner roller 9 slightly wider than the inner belt 7.

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 having a structure in which a side surface of a cable is sandwiched from both sides and a pulling belt having an endless structure is used to pull the cable.

[0002]

2. Description of the Related Art A cable pulling device for gripping a cable and pulling it in a certain direction is used in a cable manufacturing line and a cable laying work. FIG. 2 shows a side view of a conventional cable pulling device used for cable laying and the like. This apparatus has a structure in which a pair of endless traction belts 2 are provided so as to sandwich a cable 1 and the traction belts 2 are rotationally driven.

The outer peripheral surface 2A of the tow belt 2 is pressed against the side surfaces of the cable 1 in a pair of upper and lower sides. Also,
On the inner peripheral surface 2B of the traction belt 2, tooth grooves 3 are continuously provided at a constant pitch. A drive wheel 4 and a driven wheel 5, which are toothed so as to mesh with the tooth groove 3, adjust the overall tension of the traction belt 2. Further, in the portion where the outer peripheral surface 2A of the traction belt 2 continuously and linearly contacts the side surface of the cable 1, the plurality of support rollers 6 are provided with the tooth grooves 3 of the traction belt 2.
Are arranged at substantially equal intervals so as to mesh with. In the cable pulling device configured as described above, the drive wheel 4 is rotationally driven by a driving device (not shown), and the pair of pulling belts 2 sandwich the cable 1 and pull the cable 1 in a fixed direction.

[0004]

By the way, the above-mentioned conventional apparatus has the following problems to be solved. FIG. 3 shows an explanatory diagram of the force applied to the cable pulling device and the cable. As shown in the figure, if the cable 1 is sandwiched between a pair of traction belts 2 and the cable is pulled, the following force acts on each part. First, the cable 1 of the tow belt 2
Let W be the force pushing the side surface of. Further, the friction coefficient between the traction belt 2 and the cable 1 is μ. In this way, the following relational expression holds. F = 2 μW For example, to pull an optical fiber cable, F = 200 Kg
f is required, but μ = 0.3, so W = 330 Kgf
Becomes

In order to increase the cable pulling force F from the above relational expression, the force W for pushing the cable 1 by the pull belt 2 must be increased. For this purpose, it is particularly preferable that the outer peripheral surface 2A of the traction belt 2 contacts the side surface of the cable 1 with a uniform pressure over a wide area as much as possible.

However, the supporting roller 6 as shown in FIG. 2 has a gear cut on its outer peripheral surface so as to mesh with the tooth groove 3 provided on the traction belt 2. Therefore, in order to maintain good meshing between the support roller 6 and the traction belt 2, there is a restriction that the support roller 6 must have a radius of a certain value or more. Therefore, there is a problem in that the number of support rollers 6 cannot be increased unnecessarily, and it is not easy to press the traction belt 2 on the side surface of the cable 1 as a whole. Further, since the radius of the supporting roller 6 is limited and becomes large, there is a problem that the weight of the entire laying device cannot be reduced.

The present invention has been made in view of the above points, and provides a cable pulling device having a structure capable of strongly pressing a traction belt having a tooth groove on its inner peripheral surface to a cable side surface at its straight portion. The purpose is.

[0008]

SUMMARY OF THE INVENTION A cable pulling device of the present invention is formed on an endless traction belt arranged so as to contact an outer peripheral surface of a cable and sandwich the cable, and an inner peripheral surface of the traction belt. A gear wheel meshing with the tooth groove is formed on the outer peripheral surface, and a drive wheel for applying a driving force to the traction belt, and an outer peripheral surface on the inner peripheral surface of the traction belt at least at a portion where the traction belt contacts the cable. And an inner roller having an endless structure that is driven by the traction belt in close contact with each other, and an inner roller that secures a contact pressure exerted on the cable by the traction belt via the inner belt. .

[0009]

In this device, the inner belt having the endless structure is arranged along the inner peripheral surface of the traction belt having the tooth groove on the inner peripheral surface. The inner belt is a smooth belt on both the inner and outer surfaces,
It is pressed against the tow belt by the smooth inner roller. Since the inner roller does not require gear cutting, a large number can be provided with a sufficiently small outer diameter, so that the traction belt is pressed against the side surface of the cable by the inner belt with a uniform force along the longitudinal direction.

[0010]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a side view showing an embodiment of a cable pulling device of the present invention. This device is provided with a pair of traction belts 2 arranged so as to press the outer peripheral surface of the cable 1 on the side surface thereof, as in the conventional device. The outer peripheral surface 2A of the tow belt 2 is in contact with the side surface of the cable 1, but the inner peripheral surface 2
A tooth groove 3 is formed in B similarly to the conventional device, and a driving wheel 4 and a driven wheel 5 are provided so as to fit into the tooth groove 3.

Further, in the device of the present invention, another inner belt 7 having an endless structure is provided inside the traction belt 2. The inner belt 7 is stretched around a pair of tension rollers 8, and the outer peripheral surface 7A thereof is a pull belt 2.
Is arranged so as to be in close contact with the inner peripheral surface 2B. That is,
An outer peripheral surface 7A of the inner belt 7 is a portion where the traction belt 2 is in close contact with the side surface of the cable 1 linearly along the longitudinal direction.
Is in close contact with the inner peripheral surface 2B of the tow belt 2.

FIG. 4 is a sectional view of the apparatus shown in FIG. 1 taken along the line XX. As shown in FIG. 4, the cable 1 is directly sandwiched between the pair of traction belts 2 and is pressed against the cable 1 by an inner belt 7 having a width slightly wider than the traction belt 2. When the drive wheel 4 shown in FIG. 1 is driven, the cable pulling device of the present invention configured as described above starts rotating the traction belt 2 in the direction of arrow 15, and the cable 1 sandwiched between the pair of traction belts 2 is indicated by arrow 16. Is taken in the direction. At this time, as the traction belt 2 rotates, the inner belt 7 that is in close contact with the inner peripheral surface 2B of the traction belt 2 for a certain length starts to rotate. The inner belt 7 is a belt having a normal flat surface, and is pressed against the traction belt 2 with a uniform force at a relatively short pitch by an inner roller 9 having a slightly wider width as shown in FIG.

A tension adjusting bolt 10 is attached to one of the rotary shafts of the tension roller 8 around which the inner belt 7 is stretched. The tip of the tension adjusting bolt 10 is a frame 1 provided on a frame of a device (not shown).
1 is supported by using an adjusting nut 12. By rotating this adjusting nut 12, the tension adjusting bolt 1
0 moves in the longitudinal direction, and the tension state of the inner belt 7 can be adjusted.

Since the inner peripheral surface of the inner belt 7 has no tooth groove and the inner roller 9 does not need to be toothed, the inner roller 9 can have a sufficiently small outer diameter. The inner belt 7 is made of rubber, leather, steel or the like. The inner roller 9 is made of metal or rubber.

With the above-described structure, in the cable pulling device of the present invention, the outer peripheral surface 2A of the traction belt 2 is
Can be pressed against the side surface of the cable 1 with a maximum pressure over a wide area, and thus high traction force can be exhibited.

The present invention is not limited to the above embodiments. In the above embodiment, the traction roller is driven by one drive wheel, but the drive wheel and the driven wheel may be driven by both wheels without making a distinction. Further, the number and radius of the inner rollers 9 for pressing the inner belt 7 against the tow belt 2 may be freely selected according to the shape and design of the device.

[0017]

As described above, the cable pulling device of the present invention is one in which the traction belt has the tooth groove formed on the inner peripheral surface thereof and is driven by the drive wheel having the tooth groove formed on the outer peripheral surface thereof. Since the endless inner belt that is driven together with the traction belt is used by bringing the outer peripheral surface into close contact with the traction belt at the portion that comes into contact with the cable, an inner roller is used to secure the contact pressure that the traction belt exerts on the cable. The outer diameter can be sufficiently small.
Therefore, it is possible to obtain the required traction force by pressing the outer peripheral surface of the traction belt against the side surface of the cable with a uniform force by a large number of inner rollers.

Further, as compared with the case of using a supporting roller that meshes with the tooth groove formed on the inner peripheral surface of the traction belt, the chance of damaging the tooth groove of the traction belt is reduced, and the life of the traction belt is extended. Can be achieved. Also, since the inner roller can have a sufficiently small radius,
The overall size and weight of the device can be reduced. For example, when the inner belt is used, the minimum outer diameter of the inner roller can be set to about 20 mm, as compared with the case where the conventional supporting roller having teeth has an outer diameter of 40 mm.

[Brief description of drawings]

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

FIG. 2 is a side view of a conventional cable pulling device.

FIG. 3 is an explanatory diagram showing a relationship of forces applied to respective parts of the cable pulling device.

FIG. 4 is a cross-sectional view taken along line XX in FIG. 1 of the cable pulling device of the present invention.

[Explanation of symbols]

 1 Cable 2 Traction Belt 2A Traction Belt Outer Surface 2B Traction Belt Inner Surface 4 Drive Wheel 7 Inner Belt 9 Inner Roller

Claims (1)

[Claims] 1. A traction belt having an endless structure arranged so as to sandwich the cable by bringing the outer peripheral surface into contact with the cable, and a gear cutting meshing with a tooth groove formed on the inner peripheral surface of the traction belt is formed on the outer peripheral surface. And a drive wheel that gives a driving force to the traction belt, and an endless structure in which at least a portion where the traction belt comes into contact with the cable, an outer peripheral surface is closely contacted with an inner peripheral surface of the traction belt and is driven together with the traction belt. And an inner roller that secures a contact pressure exerted on the cable by the traction belt via the inner belt.