JPH1198636A - Cable laying method and cable feeding device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a cable laying method which can be extended without loosening the cable. A cable drum on which a long cable is wound is rotatably installed on a manhole. The long cable 3 pulled out from the cable drum 5 is inserted into the manhole 2
The cable is then extended to the underground cableway 1 as an underground cable installation path. At this time, the long cable 3 is laid out while being pulled out of the cable drum 5 by the cable feeder 47 on the ground while constantly applying a constant braking torque to the cable drum 5 on the ground by a brake capable of adjusting a braking force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable laying method for extending a cable such as a long ultra-high voltage cable from the ground to a cable laying path underground and laying the cable from a cable drum by the laying method. The present invention relates to a cable feeding device for feeding.

[0002]

2. Description of the Related Art Conventionally, a cable laying operation of extending a cable from the ground to an underground cable laying path is performed by attaching a manual brake such as a band brake to a cable drum on the ground.
Apply a brake to the cable drum according to the situation, so that the braking force is too large and the tension does not increase, and the braking force is too small and the cable slacks downward at the cable drum and it comes into contact with the ground etc. Laying work while taking care not to damage them. In particular, when the installation of the cable is stopped, the rotation of the cable does not stop instantaneously due to the inertia of the cable drum, and the cable continues to be extended for the length of the inertia extension during the inertial rotation. It was necessary to apply a brake so that it became loose and did not touch the ground.

[0003]

However, such a conventional method of laying a cable, for example, has a cable length of 1800.
When applied to the installation of a long cable that is difficult to bend and has a large weight, such as a long ultra-high-voltage cable such as a long ultra-high-voltage cable, when the cable is started to be fed, during feeding, or when the feeding is stopped, etc. There is a problem that a great burden must be placed on the operator. In addition, there is a problem that it is very difficult to control the rotation of a cable drum wound with a long cable. Further, there is a problem that it becomes difficult to absorb the inertia feeding length when the rotation of the cable drum is stopped.

[0004] It is an object of the present invention to provide a cable laying method and a cable feeding device capable of feeding a cable without loosening.

It is another object of the present invention to provide a cable laying method and a cable feeding device which can easily start the cable feeding.

Another object of the present invention is to provide a cable laying system which can easily absorb even a long cable having a large rigidity, which is difficult to bend, and a large weight, when the cable is stopped when the cable is stopped. It is to provide a method.

Another object of the present invention is to prevent the rotation of the cable drum when the power supply to the motor is cut off while the motor for rotating the cable drum is connected to the cable drum side. It is an object of the present invention to provide a cable feeding device which can perform the above operation.

Another object of the present invention is to provide a cable feeding device having a brake whose braking force can be easily adjusted.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a cable drum wound with a cable is rotatably installed on the ground, and the cable fed from the cable drum is extended through a manhole to an underground cable laying path and laid. To improve the cable laying method.

In the present invention, the cable is pulled out from the cable drum by the cable feeder on the ground while constantly applying a constant braking torque to the cable drum on the ground by a brake capable of adjusting the braking force.

If the cable is pulled out from the cable drum by the cable feeder on the ground while constantly applying a constant braking torque to the cable drum by the ground brake whose braking force is adjustable, the weight is very large and the inertia is very high. Even when pulling out a long cable that is heavy and difficult to bend from a cable drum that has become large, the wound cable does not come loose and the cable drum rotates constantly according to the cable feeding machine, preventing unnecessary rotation. The cable can be unwound without being loosened.

At this time, at the time of starting the cable feeding, the cable is fed while rotating the cable drum by the drive of the ground motor, and the leading end side of the cable reaches the ground cable feeding machine, and the cable can be pulled out from the cable feeding machine. When the condition is reached, the cable is pulled out from the cable drum by the cable feeder on the ground, while stopping the drive by the motor and applying a constant braking torque to the cable drum on the ground with a brake that can adjust the braking force at all times. Is preferred.

As described above, at the start of the cable feeding, if the cable is fed while rotating the cable drum by the drive of the motor on the ground, even if the cable drum is wound up and becomes extremely heavy, the cable drum can be easily drawn. The cable can be fed by rotating the cable. When the leading end of the cable reaches the cable feeding machine on the ground and is in a state in which the cable can be pulled out from the cable feeding machine, the rotation of the cable drum by the motor is stopped.
Next, when the cable is pulled out and laid by the cable feeding machine while constantly applying a constant braking torque to the cable drum with a brake that can adjust the braking force on the cable drum, the cable is very heavy and the inertia is very large When pulling out a long cable which is heavy and hard to bend from the drum, unnecessary rotation of the cable drum can be prevented, and therefore, the cable can be drawn out without slack.

At the time of stopping the feeding of the cable, it is preferable to stop the rotation of the cable drum within a time period in which the bent portion of the cable from the manhole to the cable laying path can change its curved shape to absorb the inertial feeding length.

With this arrangement, even if the cable has a large rigidity, is hard to bend, and has a large weight, the inertial feeding length at the time when the feeding of the cable is stopped is reduced so that the absorption from the manhole to the cable installation path is reduced. This can be easily done by changing the curved shape at the curved portion of the cable at the point.

A cable feeding device used in such an application has a structure including a motor for forcibly rotating a cable drum around which a cable is wound, and a torque transmitting mechanism for transmitting the torque of the motor to the cable drum. Use A clutch is interposed between the motor and the torque transmitting mechanism. The clutch is "disengaged" in the torque transmission mechanism
The brake is operated to apply a brake to the cable drum, and a brake capable of adjusting the braking force that operates so as not to apply a brake to the cable drum when the clutch is "on" is connected.

When the cable feeding device is configured as described above, at the time of starting feeding of the cable, the cable can be fed while rotating the cable drum by driving the motor by setting the clutch to "on". For this reason, even if the cable drum has a very large weight by winding a long cable, the cable can be easily rotated and fed out. When the leading end of the cable reaches the cable feeding machine on the ground and the cable can be pulled out from the cable feeding machine, the clutch is turned off to stop the rotation of the cable drum by the motor. The cable can be laid while being pulled out of the cable drum by the cable feeding machine while always applying a constant braking torque by the brake whose braking force is adjustable. For this reason, even when a long cable that is heavy and hard to be bent is pulled out from a cable drum having a very large weight and a large inertia, unnecessary rotation of the cable drum can be prevented, and the cable can be relaxed. Can be paid out without any need.

In this case, it is preferable to connect a mechanical brake that applies a brake to the cable drum when the power supply to the motor is stopped while the clutch is in the “on” state.

If the mechanical brake is provided in this way, the cable drum rotates when the motor for rotating the cable drum is connected to the cable drum side and power supply to the motor is cut off. Can be prevented, and unnecessary rotation of the cable drum can be prevented.

When a powder brake is used as a brake whose brake force can be adjusted, the brake force can be easily adjusted by adjusting the exciting current.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 5 show an example of an embodiment in which a long cable is laid by a cable feeding device for carrying out a cable laying method according to the present invention.

In the present example, a cableway 1 as a cable laying route provided along a laying route deep underground is provided.
From manhole 2 weight 43 kg / m, cable length 1800
A case is shown in which a long cable 3 made of a long CV cable, such as m, which has a large cable rigidity, is hard to bend, and has a large weight, is used. Cable drum 5 on which such a long cable 3 is wound
Has a weight of, for example, about 90 ton. Although not shown in FIG. 1, other manholes are provided at appropriate intervals along the cave 1. In this case, the distance between the manholes is set as small as possible to reduce the number of connection portions of the long cable 3.
They are provided at intervals longer than normal intervals.

At a location on the ground adjacent to the manhole 2,
A cable feeding device 4 is provided. The cable feeding device 4 is provided with drum rotation support means 6 and 7 for rotatably supporting a large cable drum 5 on which the long cable 3 has been wound up to a required height.
One drum rotation support means 6 includes a rotation shaft 8 inserted into a center hole of one flange 5b at one end in the axial direction of the cable drum 5, and a plurality of bearings rotatably supporting the rotation shaft 8. 9, a horizontal moving table 10 supporting these bearings 9,
A support table 12 having a guide 11 for supporting each bearing 9 at a predetermined height and moving the horizontal moving table 10 in the direction of approaching and separating along the axial direction of the cable drum 5, and attached to the supporting table 12. A hydraulic cylinder 13 and the like for moving the horizontal moving table 10 in the direction of approaching and separating along the axial direction of the cable drum 5 are provided. The other drum rotation support means 7 includes a rotation shaft 14 inserted into the center hole of the other flange 5c at the other end in the axial direction of the cable drum 5, and a plurality of rotation shafts 14 rotatably supporting the rotation shaft 14. Bearings 15, horizontal moving tables 16 supporting these bearings 15, supporting each bearing 15 at a predetermined height, and moving the horizontal moving tables 16 in the direction of approaching and separating along the axial direction of the cable drum 5. A support table 18 provided with a guide 17 and a hydraulic cylinder 19 attached to the support table 18 for moving the horizontal moving table 16 in a direction of approaching and separating along the axial direction of the cable drum 5.
And a kelle 20 composed of an arm which is integrally supported by penetrating a center part of the rotation shaft 14 and holes (not shown) of a flange 5c at the other end of the cable drum 5 protruding from both ends of the kelle 20. It is configured to include a Kellen pin 21 to be inserted. Here, the required height refers to a height at which the flanges 5b and 5c of the large cable drum 5 are rotatably floated from the ground.

The center of the cable drum 5 is positioned between the drum rotation supporting means 6 and 7.
Drum lifting / lowering means 22, 23 for adjusting the height by receiving and raising / lowering the cable drum 5 on the respective flanges 5b, 5c side of the cable drum 5 for positioning with respect to the rotation shafts 8, 14 of the cable drum 5 are provided. Have been. These drum elevating means 22 and 23 are connected to the cable drum 5 by V-shaped recesses on the upper surface.
Support members 22a, 23a supporting the respective flanges 5b, 5c
And hydraulic cylinders 22b and 23b that raise and lower the cable drum 5 via these flange support members 22a and 23a.

Hydraulic cylinders 13, 19, 22b, 23
b is driven by the hydraulic pump 24.

A drum rotation mechanism 25 with a brake for rotating the cable drum 5 at a required number of revolutions while applying a brake so that the cable drum 5 does not rotate by inertia is installed on the horizontal moving table 16 and the support table 18. ing. The drum rotation mechanism with brake 25 includes a motor 26 for forcibly rotating the cable drum 5 and a rotation force transmission mechanism 28 for transmitting the rotation force of the motor 26 to the cable drum 5 via a reduction gear 27 such as a cyclo reduction gear. And

The torque transmitting mechanism 28 includes a gear 29 fixed to the outer periphery of the rotating shaft 14, a gear 30 meshing with the gear 29, and a rotating shaft 31 fixed to the outer periphery of the gear 30.
And a bearing bracket 32 that rotatably supports the rotating shaft 31 on the support base 18, a gear 33 fixed to the outer periphery of the rotating shaft 31, a gear 34 that meshes with the gear 33, and the gear 34 on the outer periphery. The rotating shaft 35 has a spline structure that is slidably supported in the axial direction while being prevented from rotating, and a bearing bracket 36 that rotatably supports the rotating shaft 35 on the support base 18. On both surfaces of the gear 34 in the axial direction, a flange 34a is provided so as to maintain a connected state so as not to come off from the gear 33 when sliding on the rotating shaft 35.

Reducer 27 for reducing the rotational force of motor 26
An electromagnetic clutch 37 is interposed between the rotating force transmission mechanism 28 and the rotating shaft 35 of the rotating force transmitting mechanism 28.

The torque transmitting mechanism 28 operates when the electromagnetic clutch 37 is "OFF" to apply a brake to the cable drum 5, and when the electromagnetic clutch 37 is "ON", applies a brake to the cable drum 5. Work not to call,
A brake 38 with adjustable braking force is connected. In this example, the brake 38 is 600 to 800 kg.
It uses a powder brake that can apply a braking torque of m. This powder brake uses an electromagnetic clutch 37.
Is turned off, a current is applied to apply a brake to the cable drum 5, and when the electromagnetic clutch 37 is turned on, a circuit is provided to cut off the circuit so that no load is applied. The braking force is adjustable. The connection of the brake 38 to the torque transmitting mechanism 28 includes a toothed wheel 40 fixed to the outer periphery of the rotating shaft 39 of the brake 38, a toothed wheel 41 fixed to the outer periphery of the rotating shaft 35, and a toothed wheel 41. This is performed by a toothed belt 42 stretched around 40 and 41.

A mechanical brake 43, which is a disc brake for applying a brake to the cable drum 5 when the power supply to the motor 26 is stopped with the electromagnetic clutch 37 turned on, is provided in the torque transmitting mechanism 28. It is connected.

In the present embodiment, such a drum rotating mechanism with brake 25 is provided with the ability to cope with the cable drum 5 of 100 ton.

A frame 45 is provided between the cable drum 5 supported by the drum rotation support means 6 and 7 and the manhole 2.
Is installed. A plurality of cable guides 46 for guiding the feeding of the long cable 3 are provided on the mount 45.
And a plurality of cable feeders 47 for feeding the long cable 3 from the cable drum 5.

Each cable guide 46 is a long cable 3
The rotating shaft 46a is rotatably supported on the gantry 45 at predetermined intervals in the feeding direction, and a roller 46b of a predetermined length attached to the rotating shaft 46a. The length of each roller 46b is set so as to gradually decrease from the upstream side to the downstream side in the moving direction of the long cable 3. When the length of each roller 46b is set in this way, the long cable 3 fed from the cable drum 5
At the position close to the cable drum 5, the distance greatly changes depending on the interval between the flanges 5b and 5c of the cable drum 5, and the traverse state of the long cable 3 hardly changes at the cable feeder 47 side.

The cable feeder 47 feeds the long cable 3 by holding the long cable 3 between a pair of endless belts and rotating and driving these endless belts. In this example, three cable feeders 47 having a traction force of 500 kg are used, and 1.5 ton
Have the ability to pay out. This cable feeding machine 4
Reference numeral 7 indicates that when the cable drum 5 is stopped rotating, the cable drum 5 is still rotating by inertia, and the feeding of the long cable 3 is maintained. When the rotation of the cable drum 5 is completely stopped, the feeding is stopped. It has become.

A bending roller guide 48 for guiding the long cable 3 into the manhole 2 from above the gantry 45 is provided at the end of the gantry 45. A cable feeding machine 49 similar to the cable feeding machine 47 is also provided in the manhole 2. In this example, one cable feeding machine 47 having a traction force of 350 kg is used.

From the vertical manhole 2 to the horizontal tunnel 1
A cable guide 50 is provided at a portion where the long cable 3 is supported and gradually curved while hanging down. In consideration of the fact that the height of the hanging part gradually decreases when the long cable 3 extends by inertia when the rotation of the cable drum 5 is stopped, the cable guide 50 is provided from the upstream to the downstream in the moving direction of the long cable 3. A pair of vertically-oriented poles 50a installed at predetermined intervals in the direction, and two vertically-oriented rollers 50b on the paired vertically-oriented poles 50a are gradually lowered in mounting position from upstream to downstream. The vertical interval between these two horizontally oriented rollers 50b is also gradually reduced.

The cable guides 52 are provided at predetermined intervals on the bottom of the installation route in the cave 1 as a cable installation route for accommodating most of the cable guide 50 at the end of the cable feeding device 4 having the above-described structure. Have been.

The cable guide 52 is composed of, for example, a horizontal roller 52a for receiving the lower surface of the long cable 3 and a vertical roller 52b existing on both sides of the long cable 3. The horizontally oriented roller 52a of the cable guide 52 is an electric roller that is forcibly rotated by being rotated by an electric motor (not shown).

As the cable feeding machines 47 and 49, a holing machine is used in this embodiment.

Next, an example of a method of laying the long cable 3 using such a cable feeding device 4 will be described.

The cable drum 5 is set on the drum rotation supporting means 6 and 7 by a crane or the like.
Support members 2 of the drum elevating means 22 and 23
The flanges 5b and 5c are placed on the flanges 2a and 23a, and in this state, the cable drums 5 are lifted via the flange supporting members 22a and 23a by driving the hydraulic cylinders 22b and 23b. When the height of the cable drum 5 coincides with the height of the axis of the rotating shafts 8 and 14, the lifting of the cable drum 5 is stopped, and then the hydraulic cylinders 13 and 19 are operated to move the horizontal moving tables 10 and 16 closer to the cable drum 5 side. Then, the rotation shafts 8 and 14 are inserted into holes in the shaft center of the cable drum 5, and the respective kelly pins 21 of the kelly 20 are inserted into holes in the flange 5 c of the cable drum 5. In this state, the flange support members 22a and 23a are lowered by the reverse operation of the hydraulic cylinders 22b and 23b, and the cable drum 5 is made rotatable.

In this state, when the feeding of the long cable 3 from the cable drum 5 is started, the motor 26
Is driven, the electromagnetic clutch 37 of the drum rotation mechanism with brake 25 is turned on. At this time, brake 38
Automatically turns to a state where the brake is not applied to the cable drum 5. When the electromagnetic clutch 37 is turned on, the rotational force of the motor 26 is transmitted to the rotary shaft 14 via the brake-equipped drum rotation mechanism 25, and the cable drum 5 is rotated by the rotation of the kelley 20 accompanying the rotation of the rotary shaft 14. Driven. Due to such forced rotation of the cable drum 5, the long cable 3 is fed from the cable drum 5.

When the distal end of the long cable 3 reaches each of the cable feeders 47 at the terminal side of the gantry 45 and the cable 3 can be pulled out from these cable feeders 47, the drive by the motor 26 is performed. The long cable 3 is laid out while being pulled out from the cable drum 5 by the cable feeder 47 while stopping and applying a constant braking torque to the cable drum 5 on the ground by the brake 38 whose braking force is adjustable. That is, when the long cable 3 can be pulled out from the cable feeder 47, the electromagnetic clutch 37 is set to "off", and the brake 38 whose brake force can be adjusted is automatically activated. In this state, when the long cable 3 is pulled out from the cable drum 5 by the cable feeder 47, a constant braking torque is always applied to the cable drum 5 by the brake 38 whose braking force is adjustable.

As described above, at the start of the feeding of the long cable 3, if the long cable 3 is fed while the cable drum 5 is rotated by the drive of the motor 26 on the ground, the long cable 3 is wound up and the weight is 90, for example. Even a very large cable drum 5 such as a ton can be easily rotated to feed out the long cable 3. When the distal end of the long cable 3 reaches the cable feeding machine 47 on the ground and is in a state where the long cable 3 can be pulled out from the cable feeding machine 47, the rotation of the cable drum 5 by the motor 26 is stopped. The long cable 3 is laid out while being pulled out by the cable feeder 47 while constantly applying a constant braking torque (for example, 600 to 800 kgm) to the cable drum 5 on the ground by the brake 38 whose braking force is adjustable.

When the cable drum 5 is laid in this manner, the cable drum 5 having a very large weight and a very large inertia is provided.
When pulling out the long cable 3 which is heavy and hard to bend, unnecessary rotation of the cable drum 5 can be prevented, so that the long cable 3 can be drawn out without slack. At this time, it is preferable to use a powder brake as the brake 38 whose brake force can be adjusted, because the brake force can be easily adjusted by adjusting the exciting current.

The long cable 3 pulled out from the cable feeder 47 descends in the manhole 2 while the bending roller guide 48 bends, and is fed out while being held by the cable feeder 49 in the middle of the manhole 2. As described above, when the long cable 3 is pulled out by the cable feeder 49 in the manhole 2 while being pulled out, the long cable 3 can be prevented from slipping down due to its own weight even when its own weight is very large. The feeding of the length cable 3 can be performed.

In the lower part in the manhole 2, the long cable 3 hangs down from the cable feeder 49, curves downward, gradually changes the direction from the vertical direction to the horizontal direction, passes through the cable guide 50, and serves as a cable laying path. The wire is extended into the sinus 1 while being placed on each cable guide 52 in the sinus 1.

When the extension of the long cable 3 is stopped, the curved shape of the curved portion of the long cable 3 from the manhole 2 to the cave 1 as the cable laying path is changed so that the inertia extended length can be absorbed. The rotation of the cable drum 5 is stopped (for example, within a few seconds). At this time, the cable feeding machine 47 maintains the feeding of the long cable 3 when the cable drum 5 is still rotating by inertia, and stops feeding when the rotation of the cable drum 5 is completely stopped.

In this way, even with a long cable 3 that is hard to bend and has a large weight, such as a stainless steel sheath, the inertial feeding length when the feeding is stopped is reduced, and the absorption of the cable is reduced from the manhole 2 by the cable. It can be easily performed by changing the curved shape at the curved portion of the long cable 3 at the place reaching the sinus 1 as a laying path.

In this example, the relationship between the brake torque (τ) by the brake 38 and the rotation stop time (t) of the cable drum 5 is as follows: τ = GDD × (V / πD) / (375 × t) (1) Here, GDD: flywheel effect V: laying speed D: twice the distance from the center of the drum 5 to the feeding position of the cable 3 Using equation (1), GDD = 735201 k in equation (1)
FIG. 6 is prepared by substituting gm, V = 7 m / min, and D = 3.51 m. From FIG. 6, the relationship between the brake torque (τ) by the brake 38 and the rotation stop time (t) of the cable drum 5 is shown. I asked. That is, when it is desired to set the rotation stop time (t) of the cable drum 5 to 2 sec, the brake torque (τ) by the brake 38 is set to 600 kgm.

In this example, when the feeding of the long cable 3 from the cable drum 5 is completed, the cable drum 5 is detached from the drum rotation support means 6, 7, and
The new cable drum 5 on which the long cable 3 has been wound is set on the drum rotation support means 6, 7, and the end of the long cable 3 is connected to the end of the long cable 3 wound on the new cable drum 5. Is temporarily connected to resume the installation.

In the present invention, after the feeding of the long cable 3 from one cable drum 5 is completed and the installation in one section is completed, the installation can be similarly performed from the manhole 2 at the start end of the next section.

[0053]

According to the present invention, the cable is laid while being pulled out from the cable drum by the cable feeder on the ground while constantly applying a constant braking torque to the cable drum on the ground by a brake capable of adjusting the braking force.
Even when pulling out a long cable that is heavy and hard to bend from a cable drum that has a very large weight and very large inertia, unnecessary rotation of the cable drum can be prevented, so that the cable is not loosened. Can be paid out.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an embodiment of a cable feeding device for performing a cable laying method according to the present invention.

FIG. 2 is a perspective view showing a configuration of a drum rotation support means and a drum rotation mechanism with a brake in the cable feeding device shown in FIG. 1;

FIG. 3 is a front view showing a configuration of a drum rotation supporting means and a drum rotation mechanism with a brake in the cable feeding device shown in FIG. 1;

FIG. 4 is a left side view of the drum rotation support means on the right side of FIG. 3;

FIG. 5 is a system diagram of the drum rotating mechanism with brake shown in FIG. 2;

FIG. 6 is a characteristic diagram showing a relationship between a brake torque (τ) by a brake used in the present example and a rotation stop time (t) of the cable drum.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cave (cable laying path) 2 Manhole 3 Long cable (cable) 4 Cable feeding device 5 Cable drum 5a Winding drum 5b, 5c Flange 6,7 Drum rotation support means 8 Rotary shaft 9 Bearing 10 Horizontal slide 11 Guide 12 Support stand 13 Hydraulic cylinder 14 Rotary shaft 15 Bearing 16 Horizontal moving table 17 Guide 18 Support stand 19 Hydraulic cylinder 20 Kelley 21 Kelley pin 22, 23 Drum lifting / lowering means 22a, 23a Flange support member 22b, 23b Hydraulic cylinder 24 Hydraulic pump 25 Drum with brake Rotating mechanism 26 Motor 27 Reducer 28 Rotating force transmitting mechanism 29, 30 Gear 31 Rotating shaft 32 Bearing bracket 33, 34 Gear 34 a Flange 35 Rotating shaft 36 Bearing bracket 37 Electromagnetic clutch 38 Brake (powder brake) 39 Rotating shaft 4 , 41 toothed wheel 42 toothed belt 43 mechanical brake (disc brake) 45 gantry 46 cable guide 46a rotation axis 46b roller 47 cable feeder 48 roller guide 49 cable feeder 50 cable guide 50a vertical pole 50b horizontal roller 52 Cable guide 52a Horizontal roller 52b Vertical roller

 ──────────────────────────────────────────────────続 き Continuing from the front page (71) Applicant 000005186 Fujikura Co., Ltd. 1-5-1, Kiba, Koto-ku, Tokyo (72) Inventor Yoshiaki Gomi 2-3-24, Yokota, Atsuta-ku, Nagoya-shi, Aichi Prefecture Chubu Electric Power Company (72) Inventor: Hayato Ishihara 2-3-24 Yokota, Atsuta-ku, Nagoya, Aichi Prefecture Chubu Electric Power Co., Inc.Central Transmission & Substation (72) Inventor: Katsuhiro Nakazawa 2, Yokota, Atsuta-ku, Nagoya, Aichi Chubu Electric Power Co., Inc. Chuo Electric Power Substation Construction Center (72) Inventor Toshio Yamazaki 2-3-24 Yokota, Atsuta-ku, Nagoya City, Aichi Prefecture Chubu Electric Power Co., Inc. Central Power Transmission Substation Construction (72) Inventor Mitsuhiro Ogiso 2-72, Yokota, Atsuta-ku, Nagoya-shi, Aichi Pref. Chubu Electric Power Co., Inc. 2-3-24 Yokota, Atsuta-ku, Nagoya-shi, Aichi Chubu Electric Power Co., Inc. Inventor Shigeo Takagi 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Tetsuji Miyamoto 2- 13-2 Sakurashinmachi, Setagaya-ku, Tokyo Sumitomo Electric Industries, Ltd. Tokyo Construction Center (72) Inventor Hiroshi Matsumoto 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Inside the Hidaka Factory, Hitachi Cable Co., Ltd. (72) Inventor Kazuaki Yoshida 1-1-5 Kiba, Koto-ku, Tokyo Stock Company Inside Fujikura

Claims (6)

[Claims] 1. A cable laying method in which a cable drum wound with a cable is rotatably installed on the ground, and the cable unreeled from the cable drum is extended and laid through a manhole to an underground cable laying path. A cable laying method, wherein the cable is laid while being pulled out from the cable drum by a cable feeder on the ground while constantly applying a constant braking torque to the cable drum by a brake capable of adjusting a braking force on the ground. 2. A cable laying method in which a cable drum wound with a cable is rotatably installed on the ground, and the cable unreeled from the cable drum is extended and laid through a manhole to an underground cable laying path. At the start of the cable feeding, the cable is fed while rotating the cable drum by the drive of the ground motor, and the leading end side of the cable reaches the ground cable feeding machine so that the cable can be pulled out from the cable feeding machine. At this time, the cable is pulled out from the cable drum by the cable feeder while stopping the driving by the motor and applying a constant braking torque to the cable drum on the ground by a brake capable of adjusting a braking force. Cable laying characterized by Law. 3. A rotation of the cable drum within a time period in which the cable can be bent at a bent portion of the cable from the manhole to the cable installation path to absorb an inertia feeding length when the cable feeding is stopped. The cable laying method according to claim 1 or 2, wherein the cable is stopped. 4. A motor for forcibly rotating a cable drum around which a cable is wound, and a rotational force transmitting mechanism for transmitting a rotational force of the motor to the cable drum, wherein a rotational force transmitting mechanism is provided between the motor and the rotational force transmitting mechanism. A clutch is interposed in the rotational force transmission mechanism, and operates when the clutch is "off" to apply a brake to the cable drum, and applies a brake to the cable drum when the clutch is "on". A cable feeding device comprising a brake capable of adjusting a braking force that operates so as not to be connected. 5. A mechanical brake for applying a brake to the cable drum when power supply to the motor is stopped in a state where the clutch is “on”, is connected to the torque transmitting mechanism. The cable feeding device according to claim 4, wherein 6. The cable feeding device according to claim 4, wherein the brake whose brake force can be adjusted is a powder brake.