JP3958438B2 - Communication cable cutter for communication cable cutter and communication cable cutter combined with the device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
This invention is for a communication cable cutter that prevents a communication cable other than the communication cable to be removed from being mistakenly cut with a communication cable cutter from among a plurality of installed communication cables when removing the communication cable. The present invention relates to an erroneous cutting prevention device and a communication cable cutter combined with the device.
[0002]
[Prior art]
In supporting the modern advanced information society, communication cables play an important role as a pipeline that conveys information. To meet the demands of society, the number of lines becomes enormous, and roads, utility poles, racks In many cases, several tens to several hundreds are bundled in one place. For this reason, it is inevitable that adjacent communication cables of the same line type are unavoidable, and for each communication cable, a tag that describes a use or the like is captured at a constant interval to distinguish individual communication cables.
[0003]
By the way, along with the recent development of the communication industry, in addition to the new installation and expansion of communication cables, the change of the laying route and the change of the line type of the communication cables are increasing, and the removal work associated therewith also tends to increase. In addition, the use of existing communication cables as optical cables has spurred this.
[0004]
Usually, the local line cable of the communication cable is several kilometers from the exchange to the subscriber's house, and the relay cable is longer than that. There are also underground manholes and aerial routes for laying communication cables. For example, on the exchange side, one communication cable of 3600 pairs branches off on the way to the subscriber side and gradually branches into many branches. When removing one of these 3600 pairs of communication cables, it is cut into several tens of meters that can be removed. The type and logarithm of the cable also varies depending on the city. Also, the principle of thorough removal is to confirm and cut off the communication cable that should be removed from one end (subscriber side) where the communication cable is cut, but there are many cases where it is cut in the middle due to construction conditions etc. .
[0005]
As a conventional method of confirming the communication cable to be removed under such conditions,
(1) Inspect the communication cable to be removed from the record drawing and mark the communication cable.
(2) If the communication cable is marked with a tag, etc., check the communication cable to be removed according to the description, and mark the communication cable.
(3) Pull the communication cable, check the communication cable to be removed by the movement, and mark the communication cable.
(4) Search for and confirm the communication cable to be removed with a confirmation device using a leakage magnetic field or electrostatic induction (for example, DCL-6 type cable searcher sold by Takachiho Sangyo Co., Ltd.). Mark.
The marked part is cut using a cable scissors, an electric communication cable cutter, a hydraulic communication cable cutter, or the like.
[0006]
[Problems to be solved by the invention]
However, there are cases of misjudgment due to mistakes in drawing or display or misunderstanding of the investigator when the above methods (1) and (2) are used as a method of confirming the cable to be removed. In addition, when using the method (3) above, there are cases in which communication cables other than the pulled communication cable move together and misjudgment, so these confirmation methods are not reliable. There is. Moreover, it can be said that these confirmation methods are inefficient for confirming one communication cable to be removed. Although the confirmation method (4) is more reliable than the methods (1) to (3) above, it requires judgment while adjusting the sensitivity of the confirmation device. Because it takes time to make a judgment, this method is not sufficiently efficient.
[0007]
In addition, when marking the communication cable to be removed confirmed by the methods (1) to (4) above, it may be possible to mark other communication cables and cause incorrect cutting, or use a cutter immediately after confirmation. Since the marking work was omitted for the reason of cutting, there are no other examples of cutting other communication cables.
[0008]
Then, considering these cases, humans are involved in the two operations of the communication cable checking operation and the communication cable cutting operation. That is, it is a human error.
[0009]
The present invention has been made to solve the above-described problems, and eliminates misjudgment and inefficiency that occur at the time of confirming the communication cable to be removed and at the time of disconnecting the communication cable. An object of the present invention is to provide an erroneous cutting prevention device for a communication cable cutter that prevents erroneous cutting, and a communication cable cutter combined with the device.
[0010]
[Means for solving the problems and their functions and effects]
In order to achieve the above object, the erroneous cutting prevention device for a communication cable cutter according to the present invention is connected to a communication cable to be removed from among a plurality of installed communication cables, and the communication cable to be removed A beacon signal transmitter for transmitting a beacon signal, which is an electrical signal for confirmation, and transmitting it to the communication cable to be removed, and removable to any one of the plurality of laid communication cables A signal detector attached to the communication cable, and when receiving an electric signal from the communication cable equipped with the signal detector via the signal detector, the electric signal is identified as the indicator signal. When the electrical signal is the beacon signal, the beacon signal receiver for confirming that the communication cable equipped with the signal detector is the communication cable to be removed, and the signal detector When the indicator signal receiver confirms that the attached communication cable is the communication cable to be removed, after the confirmation, only while the signal detector is in the attached state to the communication cable to be removed, A cutting permission signal generator that generates a cutting permission signal that enables the communication cable cutter to perform a cutting operation and continues to output the signal to the communication cable cutter.
[0011]
In such a device, the beacon signal transmitter is connected to a communication cable to be removed from among a plurality of installed communication cables, and is an electrical signal for confirming the communication cable to be removed. A beacon signal is transmitted and transmitted to the communication cable to be removed, while the signal detector is detachably attached to any one of the plurality of laid communication cables, and When the sign signal receiver receives an electric signal from the communication cable equipped with the signal detector via the signal detector, the sign signal receiver identifies whether the electric signal is the sign signal, and the electric signal is If it is the sign signal, it is confirmed that the communication cable to which the signal detector is attached is the communication cable to be removed. Then, when the sign signal receiver confirms that the disconnection permission signal generator is the communication cable to which the signal detector is attached is the communication cable to be removed, the signal detector is removed after the confirmation. Only when the communication cable cutter is attached to the communication cable to be cut, a cutting permission signal that allows the communication cable cutter to perform a cutting operation is generated and output to the communication cable cutter.
[0012]
Therefore, according to this device, the communication cable cutter can be cut only while the signal detector is attached to the communication cable that has been confirmed to be a cable to be removed. By cutting the communication cable on which the detector is attached with a communication cable cutter, it is possible to reliably cut only the communication cable to be removed without marking the communication cable to be removed. Therefore, it is possible to reliably prevent erroneous cutting by eliminating the space for human error and to make the confirmation work efficient.
[0013]
In the erroneous cutting prevention device for a communication cable cutter according to the present invention, the indicator signal transmitter has a constant current circuit that maintains a constant current value of the indicator signal transmitted to the communication cable to be removed. In this way, the level of the beacon signal output from the signal detector is automatically adjusted even if the resistance value varies due to the difference in the cable length of the communication cable to be removed or the ground resistance value varies. Therefore, it is not necessary to manually adjust the sensitivity of the beacon signal receiver, and even a non-expert can easily check the communication cable to be removed.
[0014]
Further, in the erroneous cut prevention device for a communication cable cutter of the present invention, the signal detector includes an annular magnetic core that can be partially opened and closed to sandwich the communication cable, and a winding wound around the annular magnetic core. The clamp type induction coil may be used, and in this way, the signal detector can be easily attached to and detached from the communication cable, so that the confirmation work can be made more efficient.
[0015]
Furthermore, in the erroneous cutting prevention device for a communication cable cutter according to the present invention, the signal detector may be integrated with the cutting permission signal generator. In this way, the signal detector and the cutting permission are provided. Since the handling of the signal generator becomes easy, the confirmation work can be made more efficient.
[0016]
In addition, the communication cable cutter of the present invention is combined with the erroneous cutting prevention device for communication cable cutter, and can perform a cutting operation only while the cutting permission signal is input. According to the above, the operational effect of the above-described erroneous cutting prevention device for a communication cable cutter can surely prevent erroneous cutting and can make the confirmation work efficient.
[0017]
And the communication cable cutter of this invention may be integrated with at least one of the signal detector and the cutting permission signal generator of the erroneous cutting prevention device for the communication cable cutter. Since it becomes easy to handle at least one of the signal detector and the cutting permission signal generator and the communication cable cutter, the confirmation operation can be made more efficient.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view showing the overall configuration of an erroneous cutting prevention cutter formed by combining an embodiment of the erroneous cutting prevention device for a communication cable cutter according to the present invention and a communication cable cutter. Is a transmitter as a beacon signal transmitter, 2 is a clamped induction coil as a signal detector, 3 is a beacon signal receiver integrated with the induction coil 2 and a receiver as a disconnection permission signal generator, 4 is A communication cable cutter electrically and mechanically separably connected to the receiver 3, and 5 indicates a communication cable. As shown in the figure, in the erroneous disconnection prevention device of this embodiment, the transmitter 1 has a power switch 6, a normal OK lamp 7, a battery shortage lamp 8, and an alarm buzzer 9, and the receiver 3 An induction coil opening / closing button 10, a power switch 11, a battery shortage lamp 12, an adjacent OK lamp 13, an OK lamp 14 and an alarm buzzer 15, and a communication cable cutter 4 includes a cutter blade 16, And a secondary switch 17.
[0019]
FIG. 2 is a block diagram showing the configuration of the transmitter 1. As shown, the transmitter 1 includes an oscillation circuit 21, a constant current circuit 22, a microcomputer (microcomputer) 23, and a display circuit 24. And a battery 25 and a ground detection circuit 26. The power switch 6 is interposed between the battery 25, the circuits 21, 22, 24, 25 and the microcomputer 23, and turns on the power. , Turn off. Here, the oscillation circuit 21 outputs a 300 Hz rectangular wave signal with a voltage value of 48 V when the analog switch is turned on and off with a 300 Hz rectangular wave controlled by the microcomputer 23, and the constant current circuit 22 Transmits a 300 Hz rectangular wave signal with a voltage value of 48 V when ON to 1 mA using a constant current diode and sends it as a marker signal to the core of the communication cable 5. Therefore, the allowable range is 48 kΩ for the combined resistance of cable resistance and earth ground.
[0020]
The ground detection circuit 26 detects the sign signal flowing in the communication cable 5 in order to check whether the transmitter 1 is grounded on both the exchange side and the subscriber side of the communication cable 5 and whether the transmitter 1 is loaded. A current value is detected from the constant current circuit 22 and a signal indicating the current value is sent to the microcomputer 23. In addition to controlling the oscillation circuit 21, the microcomputer 23 determines whether or not the ground is taken based on a signal from the ground detection circuit 26, and the current value of the indicator signal is too small or zero, so that the subscriber side of the communication cable 5 If it is determined that the ground is not connected, the alarm buzzer 9 is sounded through the display circuit 24 with a predetermined sound indicating that the ground is not connected, and the operator is informed that the ground is not connected. Call it a buzzer.) When the remaining amount of the battery 25 is low, the battery shortage lamp 8 is turned on via the display circuit 24.
[0021]
FIG. 3 is a block diagram showing the configuration of the receiver 3 integrated with the induction coil 2 and the communication cable cutter 4 connected to the receiver 3 as described above. Similar to what is used for a non-contact type tester or the like, it has an annular magnetic core that is partially opened and closed, and a winding wound around the annular magnetic core. The induction coil opening / closing button 10 is operated. The receiver 3 includes a changeover switch 31, a voltage amplifier 32 and a filter 33 that constitute a detection circuit based on electrostatic induction, a current amplifier 34 and a filter 35 that constitute a detection circuit based on electromagnetic induction, a frequency detection circuit 36, It has a level detection circuit 37, a microcomputer 38, a display circuit 39, and a battery 40, and the power switch 11 is interposed between the battery 40 and each of the circuits 32 to 37, 39 and the microcomputer 38. Turn the power on and off. The changeover switch 31 is electrically switched by the microcomputer 38. The opening / closing of the annular magnetic core of the induction coil 2 is also detected by the microcomputer 38 via a switch (not shown).
[0022]
Here, the change-over switch 31 is initially connected to the terminal a after the power is turned on. Therefore, the output signal from the above-described winding of the induction coil 2 is initially a voltage amplifier of a detection circuit by electrostatic induction. Supplied to 32. The voltage amplifier 32 amplifies the voltage component of the output signal of the induction coil 2 and passes it through the filter 33. The filter 33 passes through only a signal in a predetermined range including 300 Hz out of the voltage amplified output signal, and has the other frequency. The signal is cut. The frequency detection circuit 36 checks whether or not 300 Hz of the beacon signal is included. Based on the result obtained by the frequency detection circuit 36, the microcomputer 38 determines whether or not the output signal of the induction coil 2 matches the sign signal output from the transmitter 1, and the output signal is the sign signal. If they match, the changeover switch 31 is switched to the terminal b. If they do not match, the alarm buzzer 15 is switched via the display circuit 39, and the induction coil 2 is connected to the communication cable 5 (referred to as “the communication cable”) to be removed. It is made to ring with a predetermined ringing state indicating that it is not adjacent (adjacent NG), and informs the operator that it is adjacent NG (this is called “sound adjacent NG buzzer”).
[0023]
In the state where the changeover switch 31 is switched to the terminal b, the output signal from the above-described winding of the induction coil 2 is supplied to the current amplifier 34 of the detection circuit by electromagnetic induction. The current amplifier 34 amplifies the current component of the output signal of the induction coil 2, and the filter 35 cuts signals of other frequencies through only a signal in a predetermined range including 300 Hz out of the current amplified output signal. The frequency detection circuit 36 checks whether or not 300 Hz of the marker signal is included, and the level detection circuit 37 checks the current value of the signal from the filter 35. Based on the results obtained by the frequency detection circuit 36 and the level detection circuit 37, the microcomputer 38 determines whether or not the output signal of the induction coil 2 matches the indicator signal output from the transmitter 1. If they match, the adjacent OK lamp 13 indicating that the induction coil 2 is adjacent to the communication cable 5 in which the indicator signal is flowing is turned on via the display circuit 39. If the frequencies do not match, the adjacent OK lamp 13 is turned on. Is turned on and alarm buzzer 15 is sounded in a predetermined way to indicate that the earth is not connected, and informs the operator that the earth is not connected (this is called "buzzing the earth unconnected buzzer"). Call).
[0024]
Further, the microcomputer 38 determines that the communication cable 5 clamped by the induction coil 2 is used when the frequency and the signal intensity match (when the current value of the signal from the filter 35 is equal to or greater than a predetermined threshold). The OK lamp 14 indicating that the communication signal 5 is carrying the indicator signal is turned on, and communication is performed via the connector 44 that is not visible in FIG. 1 because it is located between the receiver 3 and the communication cable cutter 4. A cutting permission signal is sent to the cable cutter 4. If the frequencies match but the signal strengths do not match, the alarm buzzer 15 is not in the state of the communication cable 5 in which the indicator signal is flowing (the corresponding NG). To indicate to the worker that it is the NG (this is referred to as “ring the NG buzzer”). The connector 44 is in a connected state when the receiver 3 and the communication cable cutter 4 are mechanically connected via a hooking portion (not shown) provided in the receiver 3 and the communication cable cutter 4. When the receiver 3 and the communication cable cutter 4 are mechanically separated by removing the engaging portions, the male and female are separated.
[0025]
The communication cable cutter 4 includes a secondary switch 17, a primary switch 41 that is automatically switched by the cutting permission signal from the microcomputer 38, and a motor that drives the cutter blade 16 to open and close to cut the communication cable. 42 and a battery 43 for supplying power to the motor 42, wherein the primary switch 41 is in an ON state while the disconnection permission signal is sent from the microcomputer 38 of the receiver 3. If there is no disconnection permission signal, it is turned off. The secondary switch 17 is operated manually by an operator to control the operation of the motor 42. Regarding the operation of the motor 42 in the direction in which the cutter blade 16 opens, the primary switch 41 is turned on or off. Control is always possible only with the secondary switch 17, and the motor 42 is operated in the closing direction of the cutter blade 16 only when the primary switch 41 is in the ON state, that is, from the microcomputer 38 of the receiver 3. The secondary switch 17 can be controlled only while the permission signal is being sent.
[0026]
FIGS. 4 to 7 show the work procedure when confirming and cutting the communication cable to be removed using the erroneous cutting prevention cutter formed by combining the erroneous cutting prevention device of the above embodiment and the communication cable cutter 4. First, in step 51 of FIG. 4, as shown in FIG. 1, after confirming the communication cable 5 to be removed on the exchange side (side closer to the exchange), the subscriber side (to the subscriber) The core wires of some of the communication cables 5 marked with stars as the communication cables to be removed on the near side are grounded, or more preferably the core wires of the communication cables 5 to be removed by the method shown in FIG. The ground is set, and the signal output terminal 27 (see FIG. 2) of the transmitter 1 is connected to the core of the communication cable 5 to be removed on the exchange side, and the transmitter 1 is grounded.
[0027]
Next, when the power switch 6 of the transmitter 1 is turned on in step 52, the microcomputer 23 confirms that the power is turned on in step 53, and then checks the remaining amount of the battery 25 in step 54. The battery shortage lamp 8 is turned on. In this case, the operator replaces the battery 25 in step 56. If there is a remaining battery 25, the microcomputer 23 confirms that the communication cable 5 is grounded in step 57 and is loaded, and the exchange side or subscriber side is not grounded or no load is applied. If it is in the state, the ground unconnected buzzer is sounded at step 58, whereby the operator confirms the ground connection and the connection of the transmitter 1 at both the exchange side and the subscriber side at step 59. If it can be confirmed that the ground is removed and the load is applied, the microcomputer 23 turns on the normal OK lamp 7 in step 60 and starts transmitting the marker signal, and transmits the marker signal to the communication cable 5.
[0028]
Next, in step 61 in FIG. 5, the position on the subscriber side where the communication cable 5 to be removed is disconnected (the position where the previous subscriber side is grounded and the position where the transmitter 1 is connected). In the meantime, a part of the annular magnetic core of the clamp type induction coil 2 is opened and closed by operating the induction coil opening / closing button 10 at a position close to the position where the subscriber side is grounded, thereby integrating the induction coil 2 and the coil. The receiver 34 is attached to one communication cable 5 to be inspected among the several communication cables 5 that are grounded. Next, when the power switch 11 of the receiver 3 is turned on in step 62, the microcomputer 38 of the receiver 3 confirms that the power is turned on in step 63, and then in step 64, confirms the remaining amount of the battery 40. If not enough, the battery shortage lamp 12 is turned on. In this case, the operator replaces the battery 40 in step 66. If the remaining amount of the battery 40 is present, the microcomputer 38 sets the changeover switch 31 to the connection state to the terminal a which is the initial state, that is, the detection by electrostatic induction in step 67.
[0029]
At this time, even if the subscriber side of the communication cable (the communication cable) 5 to be removed is not grounded, the induction coil 2 detects the sign signal if it is located in the vicinity of the communication cable 5 to be removed. be able to. Therefore, the microcomputer 38 first checks the frequency of the voltage component of the output signal from the induction coil 2 in step 68, and if this matches the one of the indicator signal, the induction coil 2 is attached to the communication cable 5 to be removed. In step 69, the changeover switch 31 is switched to the connection state to the terminal b, that is, detection by electromagnetic induction. On the other hand, when the marker signal is not detected by the detection by the electrostatic induction, the induction coil 2 is separated from the communication cable 5 and is in the state shown in FIG. 8 (a) or (b). I understand that. In this case, the microcomputer 38 sounds the adjacent NG buzzer at step 70, and the operator selects another communication cable 5 as an inspection target at step 71.
[0030]
When the changeover switch 31 is connected to the terminal b, the microcomputer 38 checks the frequency and strength of the current component of the output signal from the induction coil 2 in steps 72 and 73. First, in step 72, the frequency component is checked, and if it does not match that of the beacon signal, the induction coil 2 is attached to or adjacent to the communication cable 5, but the subscriber side of the communication cable 5 It can be seen that it is not grounded and is in the state shown in FIG. 8 (c) or (d). In this case, the microcomputer 38 turns on the adjacent OK lamp 13 at step 74 and sounds the buzzer without grounding, and the operator confirms the ground connection on the exchange side and the subscriber side in step 75, respectively.
[0031]
Next, in step 73, the signal strength is checked, and when the frequencies match and the signal strength does not match (the threshold value described above is not reached), the communication is carried out and the ground signal is taken and the indicator signal is transmitted. Although the induction coil 2 is located in the vicinity of the cable 5, it can be seen that the induction coil 2 is not attached to the communication cable 5 itself, that is, the state shown in FIG. In this case, the microcomputer 38 turns on the adjacent lamp and sounds the NG buzzer at step 76, and the operator selects another communication cable 5 as an inspection target at step 77. If the frequency and the signal intensity are the same, it can be seen that the ground is taken and the induction coil 2 is attached to the communication cable 5 as shown in FIG. Then, the OK lamp 14 is turned on and transmission of the disconnection permission signal is started. Then, the microcomputer 38 confirms that the induction coil 2 is closed in the next step 79, that is, the induction coil 2 and the receiver 3 remain attached to the communication cable 5 that is currently inspected. When the induction coil 2 is opened, the OK lamp 14 is turned off at step 80 and the transmission of the cutting permission signal is stopped. When the induction coil 2 is in the closed state, the step 81 The lighting state of the OK lamp 14 and the transmission state of the disconnection permission signal are maintained. Thereby, in step 82, the confirmation of the communication cable 5 to be removed on the subscriber side is completed.
[0032]
After confirming that the communication cable 5 to be inspected is the communication cable 5 to be removed, the induction coil 2 and the receiver 3 are left attached to the communication cable 5 to be removed. 6, the cutter blade 16 of the communication cable cutter 4 is opened by operating the secondary switch 17 so that the communication cable 5 on which the induction coil 2 and the receiver 3 are mounted is connected with the cutter blade 16. The communication cable cutter 4 is connected to the receiver 3 by the previous hooking portion while being sandwiched. That is, at this time, the induction coil 2 and the receiver 3 attached to the communication cable 5 that can be confirmed serve as markings.
[0033]
After this connection, since the disconnection permission signal should have been sent from the receiver 3 to the communication cable cutter 4 via the connector 44 connected at the same time, the communication cable cutter 4 sends a disconnection permission signal in step 87. If it has not been sent yet because the induction coil 2 has been opened, etc., it waits until a cutting permission signal is sent in step 85, and a cutting permission signal is sent. If YES in step 86, the primary switch 41 is turned ON in step 86. As a result, the primary switch 41 is turned on, and the motor 42 can be operated in the direction in which the cutter blade 16 is closed by the secondary switch 17. Thereafter, in step 87, the operator operates the secondary switch 17 to cut the communication cable 5 to be removed, and in step 88, the disconnection work on the subscriber side of the communication cable 5 to be removed is performed. Complete.
[0034]
Here, after that, in step 91 in FIG. 7, the power of the receiver 3 is turned off and the communication cable cutter 4 is detached from the receiver 3. Then, after the portion of the disconnected communication cable 5 on the subscriber side is removed, one end of the remaining communication cable 5 is grounded again, and steps 92 to 113 in FIG. 7 are substantially the same as the procedure shown in FIG. Then, the ground connection is confirmed again with the induction coil 2 and the receiver 3, and when the OK lamp 14 is lit and OK is output, the induction coil 2 is removed from the communication cable 5 and the operation is completed.
[0035]
Although the present invention has been described based on the illustrated example, the present invention is not limited to the above-described example. For example, the communication cable cutter 4 and the receiver 3 are connected with a cord to enable transmission of a disconnection permission signal. Alternatively, the communication cable cutter 4 and the receiver 3 may be integrated. Then, the induction coil 2 may be separated from the receiver 3 and connected by a cord so that the detection signal of the induction coil 2 can be transmitted. Further, by using a conventionally known cable searcher for the transmitter 1 and the receiver 3, the receiver of the cable searcher outputs a disconnect permission signal only while checking the communication cable to be removed. The apparatus of this invention can also be comprised by modifying.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an overall configuration of an erroneous cutting prevention cutter that is a combination of an embodiment of an erroneous cutting prevention device for a communication cable cutter according to the present invention and a communication cable cutter.
FIG. 2 is a block diagram showing a configuration of a transmitter of the erroneous cutting prevention device of the embodiment.
FIG. 3 is a block diagram showing a configuration of a receiver and a communication cable cutter of the erroneous cutting prevention device of the embodiment.
FIG. 4 is a part of a flowchart showing a work procedure when performing confirmation and cutting work of a communication cable to be removed using the erroneous cutting prevention cutter.
FIG. 5 is a part of a flowchart showing a work procedure when performing confirmation and cutting work of a communication cable to be removed using the erroneous cutting prevention cutter.
FIG. 6 is a part of a flowchart showing a work procedure when performing confirmation and cutting work of a communication cable to be removed using the erroneous cutting prevention cutter.
FIG. 7 is a part of a flowchart showing a work procedure when performing confirmation and cutting work of a communication cable to be removed using the erroneous cutting prevention cutter.
FIG. 8 is an explanatory diagram showing an operating state of the receiver of the erroneous disconnection prevention device of the embodiment in the confirmation and disconnection work of the communication cable.
[Explanation of symbols]
1 Transmitter
2 induction coil
3 receivers
4 Communication cable cutter
5 Communication cable
6 Power switch
7 Normal OK lamp
8 Battery low lamp
9 Alarm buzzer
10 Induction coil open / close button
11 Power switch
12 Low battery indicator
13 Adjacent OK lamp
14 OK lamp concerned
15 Alarm buzzer
16 Cutter blade
17 Secondary switch
22 Constant current circuit

Claims (6)

It is connected to the communication cable (5) to be removed from among a plurality of communication cables laid out, and transmits a marker signal, which is an electrical signal for confirming the communication cable to be removed. Beacon signal transmitter (1) to be transmitted to the communication cable
A signal detector (2) removably attached to any one of the plurality of laid communication cables;
When an electrical signal is received via the signal detector from the communication cable equipped with the signal detector, the electrical signal is identified as the sign signal, and the electrical signal is the sign signal And a sign signal receiver (3) for confirming that the communication cable to which the signal detector is attached is the communication cable to be removed,
When the indicator signal receiver confirms that the communication cable to which the signal detector is attached is the communication cable to be removed, after the confirmation, the attached state of the signal detector to the communication cable to be removed A cutting permission signal generator (3) that generates a cutting permission signal that allows the communication cable cutter (4) to perform a cutting operation and continues to output to the communication cable cutter only during
An accidental cutting prevention device for communication cable cutters. The erroneous cut for a communication cable cutter according to claim 1, wherein the beacon signal transmitter has a constant current circuit that maintains a constant current value of the beacon signal to be transmitted to the communication cable to be removed. Prevention device. The signal detector is a clamp-type induction coil having an annular magnetic core capable of opening and closing a part thereof and sandwiching the communication cable, and a winding wound around the annular magnetic core. The erroneous cutting prevention device for a communication cable cutter according to claim 1 or claim 2. The erroneous cutting prevention device for a communication cable cutter according to any one of claims 1 to 3, wherein the signal detector is integrated with the cutting permission signal generator. The communication cable cutter combined with the erroneous cut prevention device for a communication cable cutter according to any one of claims 1 to 4, wherein the cutting operation can be performed only while the cutting permission signal is input. 6. The communication cable cutter according to claim 5, wherein the communication cable cutter is integrated with at least one of the signal detector and the cutting permission signal generator of the erroneous cutting prevention device for the communication cable cutter.

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