JP2528904Y2 - Power cut-off device for aerial work vehicles - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power connection / disconnection device for an aerial work vehicle.

[0002]

2. Description of the Related Art Conventionally, this type of aerial work vehicle is constructed as follows. That is, as shown in FIG. 6, a turning table 2 is provided on a vehicle 1 so as to be freely turned, and a turning means 3 (comprising a hydraulic motor, a speed reducer, etc.) is provided between the vehicle 1 and the turning table 2, and the turning table is provided for the vehicle 1. 2 is configured to be capable of turning drive. The revolving base 2 is provided with a base boom 4 whose base end is pivotally supported, an intermediate boom 5 which is fitted to the base boom 4 so as to be able to expand and contract sequentially, and a tip boom 6. Intermediate boom 5 from base boom 4)
A telescopic boom 8 that can extend and contract the boom 6 ahead of the intermediate boom 5 is arranged, and a bucket 9 is provided at a tip end of the telescopic boom 8. The telescopic boom 8 is arranged so as to be able to undulate by means of an undulating means 10 (comprising an undulating hydraulic cylinder) interposed between appropriate positions of the base boom 4 and the swivel base 2, and an insulating section formed of an insulating material on the leading boom 5. To insulate the bucket 9 from the vehicle 1. Bucket 9
A bucket swiveling means 11 (not shown, comprising a hydraulic motor or an electric motor, a speed reducer, etc.) and a bucket are disposed between the bucket 9 and the tip of the telescopic boom 8 so as to be pivotable and vertically movable with respect to the tip of the telescopic boom 8. Elevating means 12 (not shown, but constituted by a hydraulic cylinder or the like) is provided.

In the aerial work vehicle configured as described above, the upper control device 13 is mounted on the bucket 9 in order to enable the related driving operation of the telescopic boom 8 and the bucket 9 from the bucket 9 and the vehicle 1. The lower control device 14 is disposed on the vehicle 1. This upper control device 13
The lower control device 14 is configured as shown in FIG. The upper control device 13 includes an upper operation means 15, an upper calculation means 16, a bucket turning control means 17, a bucket elevating control means 18, and an upper conversion means 19. The upper operation means 15 is a means for generating an operation signal operated by an operator who has boarded the bucket 9 to perform a related drive operation of the telescopic boom 8 and the bucket 9. The upper calculation means 16 receives the signal from the upper operation means 15 and calculates and separates into a bucket-related drive control signal and a boom-related control signal. Raise control signal to bucket
This is an arithmetic unit that transmits the control signal related to the boom to the upper conversion unit 19 while transmitting the control signal to the descending control unit 18 . Based on the bucket swing control signal and the bucket elevation control signal, the bucket swing control means 17 controls the driving of the bucket swing means 11, and the bucket elevation control means 18 controls the drive of the bucket elevating means 12. The upper conversion means 19
A boom-related control signal is received from the upper calculating means 16, the signal is converted into an optical signal and transmitted to the lower control device 14, and a bucket-related control signal from the lower control device 14 is received as an optical signal and received. Electricity transmitted to 16-
Optical signal conversion means. Therefore, the upper computing means 16
Receives the bucket associated control signals from the lower control device 14 via the upper conversion means 19, transmits the bucket pivot control signal from the lower to the bucket pivot control means 17, the bucket elevator bucket elevator control signals from the lower Control means 1
8 .

[0004] The lower control device 14 is provided with a lower operating means 2
0, a lower operation means 21, a boom swing control means 22, a boom extension / contraction control means 23, a boom undulation control means 24, and a lower conversion means 25. Lower operating means 20
Is a means for generating an operation signal operated by an operator from the vehicle 1 to perform a related driving operation of the telescopic boom 8 and the bucket 9. The lower operation means 21 is
, And calculates and separates into a bucket-related drive control signal and a boom-related control signal, transmits a boom rotation control signal to the boom rotation control means 22, and transmits a boom expansion / contraction control signal to the boom expansion / contraction control means 23 The boom-up / down control signal is transmitted to the boom-up / down control unit 24 and the bucket-related control signal is transmitted to the lower conversion unit 25. Based on the boom swing control signal, the boom extension / contraction control signal, and the boom up / down control signal, the boom swing control unit 22 drives and controls the swing unit 3, the boom extension / contraction control unit 23 drives the extension / contraction unit 7 and the boom up / down control unit 2
4 controls the driving of the undulating means 10. Lower conversion means 25
Receives a bucket-related control signal from the lower calculating means 21, converts this signal into an optical signal and transmits it to the upper controller 13, and receives a boom-related control signal from the upper controller 13 as an optical signal and It is an electric-optical signal conversion means to be transmitted to the calculation means 21. Therefore, the lower operation means 2
1 receives a boom-related control signal from the upper control device 13 via the lower conversion means 25, transmits a boom swing control signal from the upper part to the boom swing control means 22, and transmits a boom stretch control signal to the boom stretch control means. 23, and a boom up / down control signal to the boom up / down control means 24 .

The upper control device 13 and the lower control device 1
Signal transmission between the four is performed by light to maintain insulation between the bucket 9 and the vehicle 1. That is, the upper conversion means 19 and the lower conversion means 25 are connected by one or more optical fibers 26 so that signals can be transmitted to each other. In order to maintain the insulation, the power supply to the upper controller 13 is performed separately from the lower battery 28 which is the power supply to the lower controller 14.
Is mounted on the bucket 9 and supplied from this. Therefore, power is supplied to the upper control device 13 and the lower control device 14 by arranging the upper power switch 29 and the lower power switch 30 on the bucket 9 and the vehicle 1, respectively. 28.

[0006]

[Problems to be Solved by the Invention] However, the aerial work vehicle constructed as described above has the following problems. That is, when the worker who has boarded the bucket 9 finishes the work and gets down from the bucket 9, he often forgets to turn off the upper power switch 29. In some cases, the work could not be performed due to the discharge. Therefore, the worker pays particular attention to forgetting to turn off the upper battery 27. When the operator forgets to turn off the upper power switch 29, the operator turns off the upper power switch 29 or turns off the upper power switch 29. In order to confirm that the user has not forgotten, he has to work to get on the bucket 9 again, which is troublesome. The purpose of the present invention is to solve such a problem. When the upper power switch 29 is turned on and off, the aerial work vehicle is in a retracted state, and at this time, a bucket or Paying attention to the fact that the tip of the telescopic boom and the appropriate position on the vehicle facing it take a close position, the upper control device is located between the tip of the bucket or telescopic boom and the appropriate position on the vehicle facing the same. An object of the present invention is to solve the above-mentioned problem by enabling transmission of a signal for controlling disconnection of a power supply.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a power connection / disconnection device for an aerial work vehicle according to the present invention is provided with a swivel that can be turned on a vehicle and a telescopic boom that can be raised and lowered on the swivel. Equipped with a bucket at the tip of the telescopic boom,
An aerial work vehicle in which the telescopic boom can be driven and operated from above the bucket by an upper control device provided at the tip of the bucket or the telescopic boom , wherein an insulating section is provided at an appropriate position of the telescopic boom, and a bucket side and a vehicle side The aerial work vehicle, which insulates the space and receives power from an upper battery mounted on the tip of the bucket or telescopic boom to operate the upper control device, puts the aerial work vehicle in the retracted position. A signal generating means provided at an appropriate position on the vehicle side where the tip of the bucket or the telescopic boom faces when positioned, and capable of generating an appropriate signal by operation from the vehicle or the turntable, and a storage position for the aerial work vehicle Is provided at the tip of a bucket or telescopic boom substantially facing the signal generating means when it is positioned at a position, and receives a signal from the signal generating means. No. receiving means, and is characterized in providing the switching means for connecting and disconnecting the control to the upper control device the power supply from the upper battery based on the signal from the signal receiving means.

[0008]

The power cut-off device for an aerial work vehicle constructed as described above operates as follows. That is, the aerial work vehicle is positioned in the storage position, and is operated from the vehicle or the swivel base to generate an appropriate signal from the signal generating means. The signal is received by the signal receiving means, and the signal from the signal receiving means is received. The switching means controls the connection and disconnection of the power supply from the upper battery to the upper control device. In short, when the aerial work vehicle is in the stowed state, power can be supplied from the upper battery to the upper control device or the supply can be stopped by operating the vehicle or the turntable. Therefore, power can be supplied to the upper control device from the upper battery or the supply thereof can be stopped by operation from the vehicle or the swivel platform. Therefore, forgetting to turn off the power switch of the upper control device and boarding the bucket again. it is possible to eliminate the work, such as. The signal line for controlling the power supply of the upper controller is connected between the tip of the bucket or telescopic boom and the vehicle.
Is not directly connected after passing
The insulation between the tip of the bucket or the telescopic boom and the vehicle in the working posture in which the boom is raised is not impaired.

[0009]

1 and 2 show an embodiment of the present invention.
This is illustrated and described below. In addition, in the description of the embodiment of the present invention,
In the present embodiment, the same reference numerals 1 to 28 and 30 shown in FIGS. 6 and 7 and described in the related art are the same in the present embodiment. I do.

FIG. 2 shows the distal end of the telescopic boom 8 of the aerial work vehicle in the retracted position,
Is an engaging portion 31b protruding from the vehicle 1 and the intermediate boom 5
And a support part 31a provided below the distal end of the boom rest 31. Reference numeral 32 denotes a first signal generating means, which is formed by an electromagnet attached to a bracket 34 arranged to protrude laterally from the engaging portion 31b. Reference numeral 33 denotes a second signal generating means, which is constituted by an electromagnet mounted on the bracket 34 so as to be arranged in parallel with the first signal generating means 32 with a slight space therebetween. 35 is a first signal receiving means, which is a bucket 9
And a reed switch mounted on the bottom surface of the first device at a position substantially opposed to the first signal generating means 32. 36
Is a second signal receiving means, which is mounted on the bottom surface of the bucket 9 at a position substantially opposed to the second signal generating means 33 and is constituted by a reed switch. The signal generating means 32 and 33 and the signal receiving means 35 and 36 thus attached are connected and operated as shown in FIG.

Hereinafter, description will be made with reference to FIG. Reference numeral 37 denotes an upper power supply operation switch provided on the vehicle 1. The upper power supply operation switch 37 is connected to the lower battery 28 and the first signal generating means 32. When operated to the position, the lower battery 2
8 and the first signal generating means 32 are connected to supply power from the lower battery 28 to the first signal generating means 32 so that the first signal generating means 32 generates a magnetic force. The upper power supply operation switch 37 is also connected to the second signal generation means 33. When the upper power supply operation switch 37 is operated to the OFF position, the lower battery 28 and the second signal generation means 33 are connected. Power is supplied from the lower battery 28 to the second signal generating means 33 so that the second signal generating means 33 generates a magnetic force. Therefore, when the aerial work vehicle is positioned in the storage position, the first signal generating means 32 and the first signal receiving means 35 have the positional relationship as described above.
When the first signal generating means 32 generates a magnetic force, the contact of the first signal receiving means 35 (reed switch) is closed. Similarly, at this time, when the second signal generating means 33 generates a magnetic force, the contact of the second signal receiving means 36 (reed switch) is closed.

Reference numeral 38 denotes a switching unit provided on the bucket 9 and includes a relay R1 and a relay R2. The relay R1 is connected to the first signal receiving means 35 connected to the upper battery 27 and the normally closed contact R2 of the relay R2.
It is interposed in the series circuit of b. Therefore, when the contact of the first signal receiving means 35 is closed, the relay R1 operates. Once activated, the relay R1 is connected to the circuit so that the normally open contact R1a 'of the relay R1 is closed and held by itself. The relay R1 is provided with a normally open contact R1a "to which the upper battery 27 and the upper controller 13 are connected.
The contact is closed by the operation of the relay R1, and power is supplied from the upper battery 27 to the upper controller 13. The relay R2 is connected to the upper battery 27 by the second
Is connected in series with the signal receiving means 36, and the relay R2 is operated when the contact of the second signal receiving means 36 is closed. Therefore, when the relay R2 operates, the normally closed contact R2b is opened to release the self-holding of the relay R1, and the supply of power from the upper battery 27 to the upper controller 13 is stopped.

The power connection / disconnection device of the aerial work vehicle thus constructed according to the present invention operates as follows. First, a case where the work is started will be described. Naturally, the aerial work vehicle is in the retracted position as shown in FIG. 2, and the telescopic boom 8 is supported by the boom rest 31. Therefore, the first signal generating means 32 and the first signal receiving means 35 (reed switch)
And second signal generating means 33 and second signal receiving means 3
6 (reed switch) is in a nearly confronting position. Here, the operator operates the lower power switch 30 to supply power from the lower battery 28 to the lower control device 14 and activates the lower control device 14. The operator also sets the upper power supply operation switch 37 to the ON state, and
Of the signal generating means 32 is operated. The first signal receiving means 35 operates by the magnetic force generated by the first signal generating means 32 and closes its contact. Therefore, the relay R1 is held by itself, and the normally open contact R1 of the relay R1 is operated by the operation of the relay R1.
a 'is closed and the upper control device 13
And the upper controller 13 is operated. As described above, the operator gets on the bucket 9 from above the vehicle 1 with the lower power switch 30 and the upper power operation switch 37 turned ON, and operates the upper operation means 15 from above the bucket 9 as described in the related art. It is only necessary to operate the aerial work vehicle.

Next, a case where the operation is completed will be described. Naturally, the aerial work vehicle is a telescopic boom 8 as shown in FIG.
In a retracted position to be supported by the boom rest 31. Yo
Te, said first signal generating means 32 and the first signal receiving unit 35 (reed switch) and the second signal generating means 33
And the second signal receiving means 36 (reed switch) are in a position where they are closely opposed to each other. Here, the worker
When the vehicle 1 descends, the lower power switch 30 and the upper power switch 37 are turned off. When the lower power switch 30 is turned off, the supply of power from the lower battery 28 to the lower controller 14 is stopped. The second signal generating means 33 is activated by the OFF state of the upper power supply operation switch 37. The second signal receiving means 36 operates by the magnetic force generated by the second signal generating means 33 to close its contact. Accordingly, the normally closed contact R2b of the relay R2 is opened to release the self-holding of the relay R1, and the normally opened contact R1a ″ of the relay R1 is opened to stop supplying power from the upper battery 27 to the upper controller 13.

Therefore, since the power switch of the upper control device 13 is not provided on the bucket 9 side and is operated from the vehicle 1, the power switch of the upper control device 13 may be forgotten to be turned off and the user may board the bucket 9 again. Work can be eliminated. In addition, since the signal line for controlling the power supply of the upper control device 13 is not directly connected between the bucket 9 and the vehicle 1, the insulation between the bucket 9 and the vehicle 1 is not impaired.

In the above embodiment, the case where the upper power supply operation switch 37 is provided on the vehicle 1 side has been described. However, as shown in FIG. 3, the operation can be performed without using the upper power supply operation switch 37. . Hereinafter, FIG. 3 will be described. Reference numeral 39 denotes a main switch which is always turned off when the aerial work vehicle is not used to prevent the lower battery 28 from being discharged. That is, the main switch 39 is always turned on when traveling on a high work vehicle and performing high work. When using the aerial work vehicle, the telescopic boom 8 and the bucket 9 related to the aerial work vehicle must be driven, and a hydraulic pump driven by a traveling engine of the aerial work vehicle is used to drive these. The drive related to the telescopic boom 8 and the bucket 9 is performed by the hydraulic pressure source from. And when driving this hydraulic pump with the driving engine,
The rotational output from the traveling engine is taken out by PTO.

That is, when the aerial work vehicle is driven, the PTO must always be turned off (the main switch 39 is set to O
N) and the main switch 39 is turned off (the PTO is sometimes in contact) when the aerial work vehicle is not used.
A PTO switch 40 that is activated when touching the
When the PTO switch 40 and the main switch 39 are in the ON state, the aerial work is performed by the aerial vehicle, and when any of the switches is in the OFF state, the aerial work is not performed by the aerial work vehicle. You can see that. Therefore, FIG.
The power supply is supplied to the upper controller 13 and the lower controller 14 when both switches are ON. That is, through the series circuit of the main switch 39 and the PTO switch 40, the lower controller 14 and the first signal generator 32 are connected to the lower battery 28.
The power is supplied from. R3 is a relay with an off-timer, which is connected in parallel to the lower control device 14 and the first signal generating means 32 through a series circuit of the main switch 39 and the PTO switch 40. This relay operates only for a short time when any of the PTO switches 40 is turned off. R3a is a normally open contact of the relay R3 with an off-timer. When the relay R3 with an off-timer operates for a short time, the contact is closed, and the power from the lower battery 28 is supplied to the second signal generating means 33. I am trying to supply.

In the embodiment configured as described above,
It works as follows. When working at heights with an aerial work vehicle, the main switch 39 and the PTO switch 40 are turned off.
Since the N state is set, the first state is set in the same manner as in the previous embodiment.
Of the first signal receiving means 35
The power is supplied from the upper battery 27 to the upper controller 13 by holding the relay R1 via the upper battery 27. Next, when the aerial work vehicle is not used for aerial work, the main switch 39 and PT
Since at least one of the O switch 40 is turned off, if at least one of the main switch 39 and the PTO switch 40 is turned off, the relay R3 with the off timer is activated for a short time to make the normally open contact R3a. Close. Then, the second signal generating means 33
Is activated and the relay R is transmitted through the second signal receiving means 36.
The self-holding of the relay R1 is released by the operation of 2, and the power supply to the upper control device 13 is stopped.

The above embodiment has the following effects in addition to the effects of the above embodiment. That is, since the power supply operation is performed without using the upper power supply operation switch 37, the operation of disconnecting the power supply to the upper controller 13 and the lower controller 14 can be automatically performed, and the operation of the power switch can be performed. This frees you from the hassle that must be done, and also eliminates forgetting to cut.

In the above embodiment, the case where two sets of signal generating means and signal receiving means are used has been described. However, a case where only one set is required as shown in FIG. 4 will be described. here,
A case in which the first signal generating means 32 and the first signal receiving means 35 are used will be described. Therefore, it goes without saying that the first signal generating means 32 and the first signal receiving means 35 are attached as described above. In FIG. 4, R4 is a relay with an on-timer, which operates only for a short time when the lower power switch 30 is turned on. R5 is a relay with an off timer, which is activated for a short time when the lower power switch 30 is turned off. R4a
Is a normally open contact that is closed by the operation of the relay R4 with an on-timer. R5a is a normally open contact that is closed by the operation of the relay R5 with an off timer. 41 is a first signal receiving means 3
The switching means is operated by the operation of No. 5, and is constituted by a ratchet relay R6. R6c is a contact point of the ratchet relay R6, and the connection is alternately connected to the a side and the b side with the operation of the ratchet relay R6. That is, in the case of FIG. 4, power is supplied from the upper battery 27 to the upper controller 13 or stopped in accordance with the alternate operation of the ratchet relay R6.

In the embodiment configured as described above,
It works as follows. When working at a high place with the aerial work vehicle, the lower power switch 30 is turned on. Then, while supplying power to the power supply of the lower control device 14 ,
Activate relay R4 with on-timer. When the lower power switch 30 is turned on, the relay R4 with the on-timer is activated for a short time, and the normally open contact R4a is closed for a short time. Then, the first signal generating means 32 operates for a short time, and the first signal receiving means 35 operates for a short time. Then, the ratchet relay R6 is operated, the contact of the ratchet relay R6 is connected to the a side, and power is supplied from the upper battery 27 to the upper controller 13. Next, if you are not going to work at height with an aerial vehicle,
The lower power switch 30 is turned off, the supply of power to the lower controller 14 is stopped, and the relay R5 with an off timer is operated. When the lower power switch 30 is turned off, the relay R5 with an off timer is activated for a short time, and the normally open contact R5a is closed for a short time. Then, the first signal generating means 32 operates for a short time, and the first signal receiving means 35 operates for a short time. Then, the ratchet relay R6 is activated, and the contact of the ratchet relay R6 is connected to the b side,
The power supply from the upper battery 27 to the upper controller 13 is stopped. FIG. 5 shows a diagram in which the operation relationship of the above embodiment is easily understood. In FIG. 5, A
Indicates the operating status of the lower control device 14, B indicates the operating status of the relay R4 with the on-timer, C indicates the operating status of the relay R5 with the off-timer, and D indicates the operating status of the upper control device 13.

In the above embodiment, the signal generating means and the signal receiving means are arranged between the vehicle 1 and the bucket 9. However, the signal generating means and the signal receiving means may be provided between the vehicle 1 and the distal end of the telescopic boom 8 because insulation is not impaired. Of course. When the bucket 9 is located on the driver's seat of the vehicle 1 in the storage posture of the aerial work vehicle, the signal generating means and the signal receiving means are arranged between the driver's seat of the vehicle 1 and the bucket 9 or on the driver's seat of the vehicle 1. And telescopic boom 8
May be arranged between the front end portions.

Further, in the aerial work vehicle having the storage posture as described above, it is more convenient to dispose the lower control device 14 on the vehicle 1 side. Switch 30 and upper power switch 37
Is described on the vehicle 1 side, but the swivel base 2 is rotatable with respect to the vehicle 1. If it is difficult to transmit a signal in the rotating part, the swivel base 2 is arranged on the swivel base 2. You may. In the above-described embodiment, the aerial work vehicle capable of driving and operating the telescopic boom 8 and the bucket 9 from both the upper side of the bucket 9 and the upper side of the vehicle 1 or the upper side of the bucket 9 and the upper side of the swivel 2 has been described. Of course, the present invention can also be applied to an aerial work vehicle that is not provided with an aerial vehicle or an aerial work vehicle that cannot perform a drive operation related to the telescopic boom from the lower side (the swivel 2 or the vehicle 1 side).

Next, in the above-described embodiment, an example has been described in which an electromagnet and a reed switch are used for signal generation means and signal reception means and magnetic force is used. , Static electricity, etc. may be used. However, when these are used, it is needless to say that the consumption of the upper battery 27 must be reduced.

[0025]

[Effects of the Invention] The power cut-off device for an aerial work vehicle according to the present invention, which is constructed and operated as described above, can be operated from a vehicle or a swivel base when the aerial work vehicle is in a stowed position and can be operated from an upper battery to the upper battery. The power can be supplied to the control device or the supply can be stopped. Therefore, if you forget to turn off the power switch of the upper control device and board the bucket again
Troublesome work can be eliminated. A signal line for controlling the power supply of the upper controller is connected directly between the tip of the bucket or telescopic boom and the vehicle through the boom.
Work that raised the telescopic boom
There is no loss of insulation between the tip of the bucket or telescopic boom in the position and the vehicle.

[Brief description of the drawings]

FIG. 1 is an explanatory view illustrating a power connection / disconnection device of an aerial work vehicle according to the present invention.

FIG. 2 is an explanatory view illustrating the storage posture of the aerial work vehicle according to the present invention;

FIG. 3 is an explanatory view illustrating another embodiment of the power connection / disconnection device of the aerial work vehicle of the present invention.

FIG. 4 is an explanatory view illustrating another embodiment of the power connection / disconnection device of the aerial work vehicle of the present invention.

FIG. 5 is an explanatory diagram illustrating an operation relationship of each unit in FIG. 4;

FIG. 6 is an explanatory diagram illustrating an aerial work vehicle.

FIG. 7 is an explanatory diagram illustrating a power supply disconnection device for a conventional aerial work vehicle.

[Explanation of symbols]

 Reference Signs List 1 vehicle 2 turntable 8 telescopic boom 9 bucket 13 upper control device 27 upper battery 32 first signal generating means (signal generating means) 33 second signal generating means (signal generating means) 35 first signal receiving means (signal Receiving means) 36 Second signal receiving means (Signal receiving means) 38 Switching means 41 Switching means

Claims (1)

(57) [Scope of request for utility model registration] 1. An upper control device provided with a swivel that can be swiveled on a vehicle, a telescoping boom that can be raised and lowered on the swivel, a bucket at the tip of the telescoping boom, and a tip of the bucket or the telescoping boom. Aerial work vehicle that enables the telescopic boom to be driven from above the bucket.
An insulation section is provided at an appropriate position of the telescopic boom to insulate between the bucket side and the vehicle side, and receives power supply from an upper battery mounted on the tip of the bucket or the telescopic boom to operate the upper control device. When the aerial work vehicle is in the retracted position, the bucket or the telescopic boom is provided at an appropriate position on the vehicle facing the tip end of the telescopic boom. A signal generating means capable of generating a signal, and a signal from the signal generating means provided at a position of a tip end of a bucket or telescopic boom substantially opposed to the signal generating means when the aerial work vehicle is positioned in the retracted position. Signal receiving means, and a switch for disconnecting and controlling the power supply from the upper battery to the upper control device based on a signal from the signal receiving means. Aerial power disconnection device characterized by providing the etching device.