JP7383242B2 - Telescoping ladder, method of manufacturing telescoping ladder, underground work support system - Google Patents

Description

The present invention relates to a telescoping ladder, a method for manufacturing the telescoping ladder, and an underground work support system using the telescoping ladder.

Patent Document 1 discloses a telescoping ladder that includes a pair of columns and a plurality of horizontal bars provided between the columns. The support of this telescoping ladder is constructed by connecting multiple cylindrical bodies with different diameters so that they can be stored in a nested manner, and the length can be easily changed between extending and contracting like a feeding rod. is now possible.

JP 2019-35289 Publication

By the way, the telescoping ladder of Patent Document 1 is a so-called unidirectional extension type that extends only in one direction. Therefore, the cylindrical body located at one end (for example, the base end) is the thickest, and the cylindrical body located at the other end is the thinnest. In the case of such a one-way swing type, there is no particular problem as long as the number of joined cylindrical bodies is small, but if the number of joined cylindrical bodies increases, the cylindrical body on the proximal end side may become thicker than necessary and increase in weight.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a telescoping ladder that can be reduced in weight.

The telescoping ladder 1 of the present invention includes a support 2 and a horizontal crosspiece 6, and the support 2 includes an outer cylinder 4 and an inner cylinder 5 connected to both ends of the outer cylinder 4. It is characterized in that the body 5 can be nested inside the outer cylindrical body 4.

The above-mentioned telescopic ladder 1 includes a plurality of inner cylindrical bodies 5 having different thicknesses, and the inner cylindrical bodies 5 are connected to each other in such a way that the inner cylindrical bodies 5 gradually become thinner toward the ends, and are tapered at the tip. It is preferable that

Further, it is preferable that the outer cylinder body 4 is provided with a hinge portion 4a that allows the outer cylinder body 4 to be folded.

Further, it is preferable that the support column 2 is made of a magnesium alloy.

The method for manufacturing a telescopic ladder according to the present invention is characterized in that the struts 2 are formed by cold-forming a hot-formed pipe.

The underground work support system of the present invention is connected to any one of the above-mentioned telescopic ladders 1, a wireless connection means 11 that wirelessly connects to an Internet line, and a wireless connection means 11 to construct a wireless communication environment within a tunnel 30. When the telescoping ladder 1 is installed in the manhole 20, the wireless connection means 11 is located in the part of the telescoping ladder 1 that protrudes above the ground, and the relay means is located in the part of the telescoping means located inside the tunnel 30. 12 is located.

Further, another underground work support system of the present invention includes one of the above-mentioned telescopic ladders 1, a wireless connection means 11 that wirelessly connects to the communication network 40, and a video shooting means 14 that connects to the wireless connection means 11. When the telescoping ladder 1 is installed in the manhole 20 and a part of the telescoping ladder 1 is lowered into the tunnel 30, the wireless connection means 11 and the video capturing means 14 are located in the part of the telescoping ladder 1 that protrudes above the ground. It is characterized by

Another underground work support system of the present invention includes one of the above-mentioned telescopic ladders 1, a wireless connection means 11 for wirelessly connecting to the communication network 40, and a position grasping means 16 for grasping the position of the telescopic ladder 1, When the telescopic ladder 1 is installed in the manhole 20 and a part of the telescopic ladder 1 is lowered into the tunnel 30, the wireless connection means 11 and the position grasping means 16 are located in the part of the telescopic ladder 1 that protrudes above the ground. It is characterized by

In yet another underground work support system of the present invention, one of the above-mentioned telescopic ladders 1, an identification code 15 attached to the manhole 20, a database storing information corresponding to the identification code 15, and an identification code are input. The present invention is characterized in that it includes an input means for outputting information based on the identification code 15, and an output means for outputting information based on the identification code 15.

In the telescopic ladder of the present invention, the support column includes an outer cylinder body and an inner cylinder body connected to both ends of the outer cylinder body, and the inner cylinder body can be nested inside the outer cylinder body. That is, since it is a so-called bidirectional type, it can be made lighter than a one-way type.

If the entire ladder is treated as a simple beam, a large bending moment will be applied near the center, and almost no bending moment will be applied near the ends. Therefore, if the inner cylindrical bodies are connected so that the inner cylinders become gradually thinner toward the ends and are the thinnest at the tips, it is possible to reduce the stress level and reduce the weight.

If the outer cylindrical body is provided with a hinge portion that allows the outer cylindrical body to be folded, it becomes possible to further reduce the size and make it easier to carry.

Furthermore, if the support pillar is made of magnesium alloy, it will be easier to reduce the weight.

Cold-forming a hot-formed pipe improves its mechanical performance. Therefore, according to the method for manufacturing a telescoping ladder of the present invention, it is easy to reduce the weight.

In the underground work support system of the present invention, when the telescoping ladder is installed in a manhole, the wireless connection means is located in the part of the telescoping ladder that protrudes above the ground, and the relay means is located in the part of the telescoping means located in the tunnel. , it is possible to secure communication with the ground via the communication network even within the tunnel.

In addition, in another underground work support system of the present invention, when a telescoping ladder is installed in a manhole and a part of the telescoping ladder is lowered into a tunnel, a wireless connection means and a video capturing means are attached to the part of the telescoping ladder that protrudes above the ground. Because of this location, the movement of workers up and down can be monitored remotely, ensuring the safety of workers.

In another underground work support system of the present invention, when a telescoping ladder is installed in a manhole and a part of the telescoping ladder is lowered into a tunnel, a wireless connection means and a position grasping means are installed on the part of the telescoping ladder that protrudes above the ground. Therefore, the position of the telescopic ladder can be grasped from a remote location.

Yet another underground work support system of the present invention includes an identification code attached to a manhole, a database storing information corresponding to the identification code, an input means for inputting the identification code, and outputting information based on the identification code. Since it is equipped with an output means, it is possible to easily extract the information necessary for the work from the database.

FIG. 1A is a schematic view of a telescoping ladder according to an embodiment of the present invention, in which FIG. 1A shows the ladder when it is extended, FIG. 1B shows the ladder when it is retracted, and FIG. 1C shows the ladder when it is folded. FIG. 3 is an enlarged cross-sectional view of a main part showing a retaining mechanism. FIG. 3A is an enlarged sectional view of a main part of the locking mechanism, with FIG. 3A showing the unlocked state and FIG. 3B showing the locking state. 1 is a schematic diagram of an underground work support system according to an embodiment of the present invention. It is a block diagram of the above-mentioned underground work support system. It is a schematic diagram of the underground work support system concerning other embodiments of this invention. FIG. 2 is a schematic diagram of an underground work support system according to another embodiment of the present invention. It is a schematic diagram of the underground work support system concerning yet another embodiment of this invention.

Next, one embodiment of this telescopic ladder 1 will be described in detail based on the drawings. As shown in FIGS. 1A and 1B, the telescopic ladder 1 of the present invention includes a pair of supports 2, 2 arranged substantially parallel to each other, and a plurality of horizontal bars 6 provided between the pair of supports 2, 2. It is equipped with

The support column 2 is composed of a cylindrical body 3. The cylindrical body 3 includes an outer cylindrical body 4 and an inner cylindrical body 5 connected to both ends of the outer cylindrical body 4, respectively.

The outer cylinder 4 has a substantially cylindrical shape with openings at both ends in the axial direction. Moreover, as shown in FIG. 1C, a hinge portion 4a that allows the outer cylinder body 4 to be folded is provided at approximately the center in the axial direction. A moving means 4b such as casters or wheels is provided near the hinge portion 4a to facilitate transportation in the folded state.

The inner cylindrical body 5 has a substantially cylindrical shape. The inner cylindrical body 5 can be nested in the outer cylindrical body 4, as shown in FIG. 1B. Specifically, first inner cylinders 5 whose inner diameter (inner dimension) and outer diameter (outer dimension) of the outer cylinder body 4 are approximately equal are slidably connected to both ends of the outer cylinder body 4, respectively. . Further, a second inner cylinder 5 whose inner diameter and outer diameter are approximately equal to each other is located at the end of the first inner cylinder 5 (the side opposite to the side connected to the outer cylinder 4). end). Thereafter, a plurality of inner cylindrical bodies 5 are connected in the same manner. That is, a plurality of inner cylinders 5 having different outer diameters (thicknesses) are connected such that the outer cylinder part is the thickest, gradually becomes thinner toward the end, and becomes the thinnest at the tip. In addition, in the telescopic ladder 1 shown in FIG. 1, when the ladder is used (extended), the side located below the outer cylinder 4 has up to the sixth inner cylinder 5 (n1 to n6 shown in FIG. 1A), and the upper The side located at is connected to the seventh inner cylindrical body 5 (n1 to n7 shown in FIG. 1A). However, the number of inner cylindrical bodies 5 to be connected can be changed as appropriate depending on the required length of the ladder.

The cylindrical body 3 is provided with a retaining mechanism 7 for preventing the connected cylindrical body 3 from coming off. Specifically, as shown in FIG. 2, the inner protrusion 7a is provided on the large diameter side (the side where the outer cylinder 4 and the adjacent inner cylinder 5 have smaller numbers relative to the first inner cylinder), and the inner protrusion 7a is provided on the small diameter side. An outer protrusion 7b is provided on the first inner cylinder with respect to the outer cylinder 4, the side with the larger number of the adjacent inner cylinders 5, and when the inner cylinder 5 on the small diameter side is pulled out by a predetermined amount, the inner protrusion 7a and the outer protrusion 7b are engaged and cannot be pulled out any further.

Further, the telescoping ladder 1 of the present invention includes a locking mechanism 8 for maintaining the inner cylindrical body 5 in the drawn-out state. As shown in FIG. 3, the locking mechanism 8 includes a pin 8a biased by a biasing means 8b such as a spring, and a pin hole 8c. The biasing means 8b and the pin 8a are arranged in the cylindrical body 3 on the small diameter side, and the pin hole 8c is provided in the cylindrical body 3 on the large diameter side. Then, the small diameter cylindrical body 3 is pulled out by a predetermined amount, and when the pin 8a approaches the pin hole 8c, it is automatically inserted into the pin hole 8c by the biasing force of the biasing means 8b, and the pin 8a is automatically inserted into the pin hole 8c by the biasing force of the biasing means 8b. Movement in the axial direction is restricted (see FIG. 3B). Note that the lock mechanism 8 is not limited to this, and various known mechanisms can be employed.

Returning to FIG. 1, the horizontal bar 6 has a substantially rectangular cylindrical shape, and is provided so as to connect the outer cylinders 4 and the inner cylinders 5 together. The horizontal bars 6 are substantially parallel to each other. There are four horizontal bars 6 that connect the outer cylindrical bodies 4 to each other, and one horizontal bar 6 that connects the inner cylindrical bodies 5 to each other.

As the material of the pillar 2 and the horizontal beam 6, metal or plastic can be used. Moreover, different materials may be used for the support column 2 and the horizontal beam 6. Note that from the viewpoint of ensuring strength and reducing weight, it is preferable to use a magnesium alloy. Specifically, AZ31 is preferred.

However, if AZ31 is used as is, its mechanical performance may be inferior to aluminum alloy (A6061TD-T8), which is commonly used as a material for ladders. Specifically, when comparing the yield point stress (0.2% proof stress), AZ31 is lower. Therefore, the support column 2 (cylindrical body 3) is manufactured as follows.

First, a raw tube is made by hot forming (hot extrusion). Subsequently, cold forming (cold drawing) is performed to form the cylindrical body 3. Cold forming is carried out so that the area reduction rate is reduced by 10 to 20%, preferably 12 to 18%, and more preferably 14 to 15%. Note that the cross-sectional reduction rate is (A0-A1)/A0, where A0 is the cross-sectional area of the raw pipe before cold forming, and A1 is the cross-sectional area of the raw pipe (cylindrical body 3) after cold forming. This is the value calculated by A comparison of mechanical performance is shown below.

The aluminum alloy (A6061TD-T8) has a tensile strength of 265 MPa and a 0.2% yield strength of 190 MPa, which indicates that sufficient strength is obtained after cold forming. Furthermore, since the area reduction rate is within a predetermined range, it is possible to suppress breakage and cracking during cold forming while improving mechanical performance.

There is no need to cold form the horizontal crosspiece 6. However, cold forming may also be performed.

Next, an underground work support system 10 using the above-mentioned telescopic ladder 1 will be explained. As shown in FIGS. 4 and 5, the underground work support system 10 is connected to the telescopic ladder 1, the wireless connection means 11 that wirelessly connects to the communication network 40, and the wireless connection means 11, and relay means 12 for constructing a communication environment.

When the telescoping ladder 1 is installed in the manhole 20 and a part of the telescoping ladder 1 is lowered into the tunnel 30, the wireless connection means 11 is located in the part of the telescoping ladder 1 that protrudes above the ground. The relay means 12 is configured to be located in a portion located within the road 30. Specifically, when a descending ladder is installed in the manhole 20, it is made to protrude from the manhole 20 to the ground side by 600 mm or more, and the wireless connection means 11 is arranged in this protruding part. Further, the relay means 12 is disposed in a portion located within the tunnel 30 which is shaped like a horizontal hole with respect to the manhole 20 which is shaped like a vertical hole. The wireless connection means 11 and the relay means 12 may be attached to the telescopic ladder 1 in a contracted state in advance, or may be attached after the telescopic ladder 1 is extended.

Note that the communication network 40 may be, for example, the Internet, but other networks may be used. As the wireless connection means 11, for example, a portable mobile router can be used. The relay means 12 may be, for example, a wireless LAN router. It is preferable that the wireless connection means 11 and the relay connection means are connected by wire. However, wireless connection may also be used.

(Securing underground communications)
By using the underground work support system 10 configured as described above, communication with the ground via the communication network 40 can be ensured even within the tunnel 30.

Therefore, an information terminal 13 (wearable device, smart device, etc.) connectable to the relay means 12 includes a calculation unit (CPU), a storage medium (RAM and/or ROM, HDD, SSD, etc.) and an input unit (keyboard, joystick, etc.). , a microphone, etc.) and an output section (display and/or speaker)), or the part of the telescoping ladder 1 located inside the tunnel 30 can be connected to the relay means 12. By attaching the image capturing means 14, various things become possible.

(Remote instruction)
For example, instructions can be issued to workers inside the tunnel 30 in real time from the command center 50 on the ground. If the wearable device is in the form of eyeglasses and has a display in its lens section, it is also possible to display work details on the display in real time. Furthermore, since information can be sent from workers inside the tunnel 30 to the command center 50 on the ground, if the information terminal 13 has a camera function, images of the work can be sent to the command center 50 in real time. can. Note that the video may be sent by providing a separate dedicated camera and directly connecting the camera to the relay means 12 by wireless, or by interposing a communication terminal in between. In this way, two-way communication becomes possible in real time, which reduces the number of workers dispatched to the site and improves work efficiency.

(Understanding the situation inside cave 30)
Furthermore, the situation inside the tunnel 30 can be grasped in real time by the video photographing means 14 attached to the telescoping ladder 1. Therefore, the safety of workers can be ensured.

Next, an underground work support system 10A according to a different embodiment of the present invention will be described. This underground work support system 10A, as shown in FIG. When the ladder is lowered, the wireless connection means 11 and the image capturing means 14 are located at the part of the telescopic ladder 1 that protrudes above the ground. Specifically, when a descending ladder is installed in the manhole 20, it is made to protrude from the manhole 20 to the ground side by 600 mm or more, and the wireless connection means 11 and the image capturing means 14 are arranged in this protruding part. . The image capturing means 14 is, for example, a surveillance camera, and includes a capturing section that captures moving images and still images, a calculation section that converts the captured images into digital data, and an output section that outputs the digital data to the outside. There is. The digital data is sent in real time to the command center 50 via the wireless connection means 11 that is wirelessly connected to the communication network 40 . Note that the image capturing means 14 itself may be provided with the wireless connection means 11. This image capturing means 14 mainly faces downward (toward the manhole 20 side).

(Ensuring safety)
In the underground work support system 10A having the above configuration, it is possible to check in real time from the command center 50 on the ground whether the worker has been able to climb up and down the ladder without any problems.

Next, an underground work support system 10B according to still another embodiment of the present invention will be described. This underground work support system 10B, as shown in FIG. When a part of the telescopic ladder 1 is lowered into the tunnel 30, the wireless connection means 11 and the position grasping means 16 are located in the part of the telescopic ladder 1 that protrudes above the ground. Specifically, when a descending ladder is installed in the manhole 20, it is made to protrude from the manhole 20 to the ground side by 600 mm or more, and the wireless connection means 11 and the position grasping means 16 are arranged in this protruding part. . Examples of the position grasping means 16 include a transmitter using satellite positioning such as GPS or WiFi (registered trademark) positioning. The position information grasped by the position grasping means 16 is sent to the command center 50 through the wireless connection means 11, which is integrated with or separate from the position grasping means 16.

(Position confirmation, safety confirmation, recovery of workers)
In the underground work support system 10B, the current location of the extension ladder 1 can be grasped in real time. Therefore, the command center 50 can always know where the worker is working. For example, if the location of the extension ladder 1 does not change for a long time, it can be determined that a problem may have occurred. The same applies if it is not possible to contact the worker who is supposed to be working. Furthermore, by knowing the position of the telescoping ladder 1, it is possible to easily know where to go to pick it up after the work is completed.

Next, an underground work support system 10C according to yet another embodiment of the present invention will be described. This underground work support system 10C, as shown in FIG. and output means for outputting information based on the code 15. The identification code 15 is, for example, a bar code or a two-dimensional code. The input means is, for example, a camera built into the information terminal 13 or a barcode scanner. The output means is, for example, a display of the information terminal 13. The database is recorded on a storage medium installed in the information terminal 13. However, it may be recorded in an external device, for example, in a device installed in the command center 50. In this case, the underground work support system 10B further includes a wireless connection means 11 that wirelessly connects to the communication network 40 and a wireless connection means 11 that connects with the communication network 40 to ensure communication with the surface. It also includes relay means 12 for constructing a communication environment. The information in the database includes, for example, location information, a format for inputting work results, and precautions during work.

(Simplification of work)
In the above-mentioned underground work support system 10C, by inputting the identification code 15 attached to the manhole 20 into the information terminal 13, the worker can input the position information of the manhole 20, the format for inputting the work result, and the precautions during work. can be called and work can be done efficiently. Furthermore, by transmitting the position information to the command center 50, it is possible to know in real time which manhole 20 the worker is working on. In this case, for example, when a vehicle picks up a large number of workers who are working separately at multiple locations, the vehicle can be run efficiently, such as by taking the shortest distance. Furthermore, an identification code 15a may be added to the extension ladder 1 to assist in inputting work results into the format. For example, a person who uses the telescopic ladder 1 may be registered in advance in the database, and by inputting the identification code 15a into the information terminal 13, the name of the worker may be automatically input into the format.

Each of the above-mentioned underground work support systems 10 to 10C may additionally include a lighting 17 that illuminates the inside of the tunnel 30, a portable electrode supply means 18 such as a generator or battery, and a sensor 19 such as a gas sensor. If the electrode supply means 18 is attached to the telescoping ladder 1, power can be appropriately supplied to devices that require power. Note that the electrode supply means 18 is preferably placed on the ground. A power cable is used to connect each device, but wireless power supply may also be used. If the sensor 19 such as a gas sensor is provided, the safety of work inside the tunnel 30 can be further improved. Note that the sensor 19 is preferably disposed underground, particularly within the cave 30. It may be attached to the telescopic ladder 1 in advance.

Although the embodiments of this invention have been described above, this invention is not limited to the above embodiments, and can be implemented with various changes within the scope of this invention. For example, the cross-sectional shape of the outer cylindrical body 4 and the inner cylindrical body 5 of the support column 2 is not limited to a circle, but may be a triangle, a rectangle, or a polygon of pentagon or more.

1 Telescopic ladder 2 Support 3 Cylindrical body 4 Outer cylinder 4a Hinge part 4b Moving means 5 Inner cylinder 6 Horizontal bar 7 Retaining mechanism 7a Inner protrusion 7b Outer protrusion 8 Locking mechanism 8a Pin 8b Biasing means 8c Pin hole 10, 10A, 10B, 10C Underground work support system 11 Wireless connection means 12 Relay means 13 Information terminal 14 Video shooting means 15 Identification code (for manhole)
15a Identification code (for telescopic ladder)
16 Position grasping means 17 Lighting 18 Power supply means 19 Sensor 20 Manhole 30 Tunnel 40 Communication network 50 Command center

Claims (7)

The pillar and
Equipped with a horizontal bar,
The support column includes an outer cylindrical body and an inner cylindrical body connected to both ends of the outer cylindrical body,
The inner cylindrical body can be nested inside the outer cylindrical body,
A telescopic ladder whose struts are made of magnesium alloy. Equipped with multiple inner cylinders of different thicknesses,
2. The telescoping ladder according to claim 1, wherein the inner cylindrical bodies are connected to each other in such a way that the inner cylinders become gradually thinner toward the ends, and are tapered at the tip. 3. The telescoping ladder according to claim 1, wherein the outer cylindrical body is provided with a hinge portion that allows the outer cylindrical body to be folded. 4. A method for manufacturing a telescoping ladder according to any one of claims 1 to 3, wherein the telescoping ladder uses struts formed by cold-forming hot-formed pipes. The apparatus includes a support and a horizontal beam, the support includes an outer cylinder and an inner cylinder connected to both ends of the outer cylinder, and the inner cylinder can be nested in the outer cylinder. A telescopic ladder,
a wireless connection means for wirelessly connecting to a communication network;
A relay means that is connected to a wireless connection means and establishes a wireless communication environment within the tunnel,
When the telescoping ladder is installed in the manhole and a part of the telescoping ladder is lowered into the tunnel, the wireless connection means is located on the part of the telescoping ladder that protrudes above the ground, and the relay means is located on the part of the telescoping means located inside the tunnel. Located in an underground work support system. The apparatus includes a support and a horizontal beam, the support includes an outer cylinder and an inner cylinder connected to both ends of the outer cylinder, and the inner cylinder can be nested in the outer cylinder. A telescopic ladder,
a wireless connection means for wirelessly connecting to a communication network;
Comprising a wireless connection means and a video shooting means to be connected,
This is an underground work support system in which a telescoping ladder is installed in a manhole, and when a part of the telescoping ladder is lowered into a tunnel, a wireless connection means and a video capturing means are located on the part of the telescoping ladder that protrudes above the ground. The apparatus includes a support and a horizontal beam, the support includes an outer cylinder and an inner cylinder connected to both ends of the outer cylinder, and the inner cylinder can be nested in the outer cylinder. A telescopic ladder,
a wireless connection means for wirelessly connecting to a communication network;
and a position grasping means for grasping the position of the telescoping ladder,
An underground work support system in which a telescoping ladder is installed in a manhole, and when a part of the telescoping ladder is lowered into a tunnel, a wireless connection means and a position grasping means are located on the part of the telescoping ladder that protrudes above the ground.

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