JPH07207691A - Fall-preventing device for manhole - Google Patents

Abstract

PURPOSE:To prevent such an accident that someone or something falls into a manhole, by a method wherein a fall-preventing device in composed of a main body which has a plurality of vertically-through openings and is placed at the upper part of the inside of the manhole, and fastening members by which the main body is fastened to a cover frame for the manhole. CONSTITUTION:A main body 11 in the shape of a disk has a definite gap between it and an inner wall 2 in a manhole, is placed at the upper part of the manhole, and is formed of a mesh. Fastening members 12 by which the main body 11 is removably fastened to a cover frame 13 for the manhole are fitted to definite positions around the main body 11. When a device 1 for preventing a fall from the manhole is fitted to the cover frame 13 for the manhole, engaging parts 23 for the fastening members 12 are engaged with the flange part 13A of the cover frame 13. After that, bolts 12A each are screwed to boltholes 13B through boltholes 12E and the fastening members 12 are fastened to the cover frame 13, following which a manhole cover 21 is placed on the cover frame 13 and is locked with a key, a chain or the like, if necessary. In this way, such an accident that someone or something falls into the manhole can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manhole fall prevention device, and more particularly to a manhole fall prevention device capable of preventing a fall accident into a manhole when the manhole cover is displaced or comes off. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, for the purpose of inspecting, repairing and cleaning sewers, etc., a manhole for people to come in and out has a lid for the purpose of preventing falling and blocking odors generated from inside the manhole. is set up. This manhole cover is generally installed in a state where it is detachably supported by a cover frame installed inside the opening of the manhole. Then, a simple key or chain is installed on the lid, and the lid is locked by the key or chain so as not to be displaced or come off from a predetermined position due to an external impact or the like. .

[0003]

However, if an unexpected situation occurs such that the sewer becomes full due to heavy rain, for example, the lid of the manhole will be locked by the key or chain when the internal pressure of the manhole becomes large. Even if they are locked, there is a problem that they are displaced from the predetermined position or come off.

If the lid of the manhole shifts or comes off from a predetermined position, there is a problem that a fall accident into the manhole occurs. The present invention has an object to solve such a conventional problem, and even if the manhole cover is displaced from the predetermined position or disengages from the manhole cover even if the internal pressure of the manhole becomes large in an unexpected situation, It is an object of the present invention to provide a fall prevention device for a manhole, which can prevent a fall accident to a floor.

[0005]

In order to achieve this object, the invention according to claim 1 has a size capable of being inserted into the upper part of the manhole with a predetermined gap from the inner wall of the manhole, and penetrates in the vertical direction. A fall prevention device for a manhole, comprising: a main body having a plurality of perforations formed therein; and a fixing member that detachably fixes the main body to a lid frame of a manhole.

The invention according to claim 2 is the same as claim 1.
According to another aspect of the present invention, there is provided a fall preventing device for a manhole, wherein the main body has a disc shape.

[0007]

According to the first aspect of the present invention, the main body inserted into the upper portion of the manhole is detachably fixed to the lid frame of the manhole by the fixing member. Since a plurality of perforations penetrating in the vertical direction are formed in this main body, when the manhole is not covered with a lid, the inside and outside of the manhole are circulated through the perforations. . Therefore, the pressure inside the manhole is kept equal to the pressure outside the manhole. Therefore, even if an unexpected situation occurs and the internal pressure of the manhole increases, the fall prevention device for a manhole according to the present invention,
It will not come off or come off from the manhole cover frame.

Further, even if the lid covering the manhole is displaced from the predetermined position or comes off, the upper part of the manhole is
Since the fall prevention device for the manhole is fixed,
Accidents falling into the manhole are prevented. Further, when the manhole fall prevention device according to the present invention is installed at the time of working in the manhole, it is possible to protect an object falling from the outside of the manhole into the manhole and to cure the opening. Therefore, the safety of workers is ensured.

Further, since the manhole fall prevention device according to the present invention is arranged in the upper part of the manhole, the step difference with the ground outside the manhole can be minimized. Therefore, the risk of the pedestrian or the like due to the step is minimized. Further, since the manhole fall prevention device according to the present invention is detachably fixed to the manhole cover frame, it can be easily attached to or removed from the manhole cover frame.

According to the second aspect of the invention, since the main body has a disk shape, the gap formed by the inner wall of the manhole and the outer periphery of the main body is uniform. Therefore, the size (width) of the gap can be easily controlled. Further, it can be easily attached and detached, and is fixed in a stable state by the manhole cover frame.

[0011]

An embodiment of the present invention will be described with reference to the drawings. 1 is a plan view of a fall prevention device for a manhole according to an embodiment of the present invention, FIG. 2 is a sectional view of the fall prevention device for a manhole shown in FIG. 1, and FIG.
FIG.

The manhole fall prevention device 1 shown in FIGS. 1 to 3 has a disc-shaped main body 11 which is inserted in the upper part of the manhole, that is, in the vicinity of the upper open part with a certain gap from the inner wall 2 of the manhole. , And a fixing member 12 for detachably fixing the main body 11 to the manhole cover frame 13. The manhole cover frame 13 has a substantially U shape, and is attached to the upper part of the manhole surrounded by the manhole outside 14 with the open side facing up. The flange portion 13A arranged on the manhole center side of the manhole cover frame 13 is provided with a bolt hole 13B through which a bolt 12A for fixing a fixing member 12, which will be described in detail later, penetrates. That is,
The fixing member 12 is detachably fixed to the flange portion 13A.

The disc surface of the main body 11 is a mesh (in this embodiment, a mesh having perforations of about 50 mm × 50 mm) formed by combining stainless steel columnar members (in this embodiment, φ9 mm is used). Used). In other words, the manhole fall prevention device 1 is provided with a plurality of perforations formed in the vertical direction when installed in the manhole. Further, a stainless frame 11A is arranged on the outer periphery of the disc surface.

In this embodiment, the perforations formed by the mesh correspond to the "perforations" recited in the claims. A bolt 1 for fixing the fixing member 12 to the frame 11A.
Four bolt holes 11B through which 2B penetrates are provided at equal intervals. The fixing member 12, as shown in FIG.
A main body support portion 22 having an L-shaped cross section for supporting the main body 11,
The main body supporting portion 22 has a substantially U-shaped cross section continuous from the upper end portion thereof, and includes an engaging portion 23 that engages with the flange portion 13A of the manhole cover frame 13. In this example, a stainless steel fixing member was used.

A bolt 12 for fixing the main body 11 is attached to a flange portion 22A formed at the lower end of the main body supporting portion 22.
A bolt hole 22B through which B passes is provided. Then, the bolt 12B is provided in the bolt hole 11B provided in the frame 11A and the bolt hole 22B provided in the flange portion 22A.
Through, and by screwing the nut 12D into this,
The fixing member 12 is fixed to the main body 11.

The fixing members 12 are fixed to all the positions (four positions in this embodiment) of the main body 11 where the bolt holes 11B are provided, in the same manner as described above. A bolt hole 12E, through which a bolt 12A for detachably fixing the fixing member 12 is inserted, is provided in the manhole cover frame 13 at a portion of the engaging portion 23 that is continuous with the main body supporting portion 22. Then, the engaging portion 23 is engaged with the flange portion 13A, and the bolt 1 is inserted into the bolt hole 12E and the bolt hole 13B.
The fixing member 12 is fixed to the lid frame 13 of the manhole by screwing 2A.

A rubber packing 12C is attached to the rear surface of the engaging portion 23 which comes into contact with the upper portion of the flange portion 13A, that is, the portion where the manhole cover 21 comes into contact. The rubber packing 12C blocks the flow between the inside of the manhole and the outside of the manhole when the manhole cover 21 is covered. Next, a specific operation of the manhole fall prevention device 1 according to the present embodiment will be described.

When the manhole fall prevention device 1 is attached to the manhole cover frame 13, first, the engaging portion 23 of each fixing member 12 is engaged with the flange portion 13A of the manhole cover frame 13. Next, the bolt 12A is screwed into the bolt hole 12E and the bolt hole 13B, and each fixing member 12 is attached to the lid frame 13 of the manhole. After that, the manhole cover 21 is covered, and if desired, locked with a key or a wedge.

In this state, if an unexpected situation occurs, for example, the sewer becomes full due to heavy rain, and the internal pressure of the manhole increases, the internal pressure causes the lid 21 of the manhole to shift or come off. The pressure inside the manhole is released outside the manhole. At this time, since the manhole fall prevention device 1 has a mesh shape, the inside and outside of the manhole is circulated through the perforations of the mesh. Therefore, the pressure inside the manhole can always be kept equal to the pressure outside the manhole. For this reason, the manhole fall prevention device 1 does not shift or come off from the manhole cover frame 13. Therefore, even if the manhole cover 21 is displaced from the predetermined position or comes off, the upper part of the manhole (near the opening) is
Since the manhole fall prevention device 1 is always attached, a fall accident into the manhole can be prevented.

Further, since the manhole fall prevention device 1 is mounted on the upper part of the manhole, it is possible to minimize the step difference formed between the manhole fall prevention device 1 and the ground outside the manhole 14. Therefore, it is possible to avoid a risk that the step causes a pedestrian or the like. On the other hand, when working in the manhole, the manhole fall prevention device 1 is removed from the manhole cover frame 13. Specifically, loosen the bolt 12A to remove the bolt hole 1
The manhole fall prevention device 1 can be easily removed from the manhole cover frame 13 by pulling it out from 3B and the bolt hole 12E.

After that, a worker enters the manhole to perform work. At this time, the manhole cover frame 13 is provided on the manhole cover frame 13 for the purpose of protecting fallen objects from the outside 14 of the manhole and curing the opening of the manhole. Attach the fall prevention device 1 again. At this time, if the engagement portion 23 of the fixing member 12 is engaged with the flange 13A of the manhole cover frame 13, the purpose of protection and curing can be achieved. Therefore, a worker who has entered the manhole can easily and safely attach and detach the manhole fall prevention device 1.

When the work in the manhole is completed, the manhole drop prevention device 1 may be fixed to the manhole cover frame 13 and the manhole cover 21 may be covered by the same method as described above. In this embodiment, the manhole fall prevention device 1 that is permanently installed (attached when the cover 21 is placed on the manhole) is used during the work in the manhole, but the present invention is not limited to this, and the manhole fall device is not limited to this. At the time of work, for example, as shown in FIG. 4, the manhole fall prevention device 1A in which the main body 110 and the fixing member 120 are integrated may be used.

In this embodiment, the manhole cover frame 1 is also used.
Although the fixing member 12 having a structure in which the engaging portion 23 is engaged with the flange portion 13A of No. 3 has been described, the present invention is not limited to this, and for example, as shown in FIG. The fixing member 120B is bolted, and the frame 1 of the main body 11 is attached to the end of the fixing member 120B on the center side of the manhole.
The fixing member according to the present invention may have another structure as long as the main body is detachably fixed to the lid frame 13 of the manhole, such as a structure in which 1A is detachably fixed.

Further, in this embodiment, the bolt 12B is used.
Thus, the manhole drop prevention device 1 having a structure in which the fixing member 12 is fixed to the main body 11 and the fixing member 12 is detachably fixed to the manhole cover frame 13 has been described, but the manhole according to the present invention is not limited to this. In the fall prevention device for use, the fixing member 12 is fixed to the lid frame 13 of the manhole, and the main body 11 is detachably fixed to the fixing member 12 with the bolt 12B, so that the main body 11 is fixed to the lid frame 13 of the manhole. It may be removable.

Further, in this embodiment, the fixing member 12 is fixed to the four places of the main body 11, but the present invention is not limited to this, and the fixing member 1 is not limited thereto.
The number and the installation location of the two may be arbitrarily set as long as the manhole fall prevention device 1 can be stably and detachably fixed to the manhole cover frame 13. Further, in the present embodiment, the main body 11 has a disc shape, and the main body 11 is provided with perforations by mesh, but the present invention is not limited to this, and the main body according to the present invention may be, for example, fall prevention or fallen objects. A size that can be inserted into the upper part of the manhole with a specified gap from the inner wall of the manhole, such as irregularly piercing holes, provided that it does not interfere with protection or curing of the opening. Other structures may be provided as long as they are provided with a plurality of perforations formed in the vertical direction.

In this embodiment, stainless steel is used as the material for forming the main body 11 and the fixing member 12, but the material of the main body 11 and the fixing member 12 is not limited to this, and is sufficient for the manhole fall prevention device 1. Other materials may be used as long as they have sufficient strength and little deterioration due to rust or the like.

[0027]

As described above, in the manhole fall prevention device according to the first aspect of the present invention, there is provided a main body in which a plurality of vertical holes are formed and which is inserted into an upper part of the manhole, and the main body is a manhole. Since it is configured to include a fixing member that is detachably fixed to the lid frame, when the manhole is not covered with the lid, the manhole and the outside of the manhole can be communicated through the perforation. Therefore, the pressure inside the manhole can always be kept equal to the pressure outside the manhole. Therefore, even if an unexpected situation occurs and the internal pressure of the manhole increases, the manhole is not displaced or disengaged from the cover frame of the manhole. As a result, a fall accident into the manhole is prevented.

Further, at the time of working in the manhole, it is possible to protect the fallen object from the outside of the manhole into the manhole and to protect the opening, so that the safety of the worker can be secured. Further, the step difference with the ground outside the manhole is minimized, and the risk of the pedestrian or the like due to the step difference can be minimized. Also, it can be easily attached to or removed from the manhole cover frame.

Further, in the manhole drop prevention device according to the second aspect, since the main body has a disk shape, the gap formed by the inner wall of the manhole and the outer periphery of the main body can be made uniform. Therefore, the size (width) of the gap can be easily controlled. As a result, in addition to the effects described above, the attachment / detachment can be performed more easily, and the manhole cover frame can be fixed in a stable state.

[Brief description of drawings]

FIG. 1 is a plan view of a fall preventing device for a manhole according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the manhole fall prevention device shown in FIG.

FIG. 3 is a partially enlarged view of FIG.

FIG. 4 is a sectional view of a fall preventing device for a manhole according to another embodiment of the present invention.

FIG. 5 is a sectional view of a fall preventing device for a manhole according to another embodiment of the present invention.

[Explanation of symbols]

 1 Fall prevention device for manhole 2 Inner wall of manhole 11 Main body 12 Fixing member 13 Manhole cover frame 14 Manhole outside 21 Manhole cover

Claims (2)

[Claims] 1. A main body having a size capable of being inserted into an upper part of the manhole with a predetermined clearance from an inner wall of the manhole and having a plurality of perforations vertically formed therethrough, and the main body being attached to and detached from a lid of the manhole. A fall prevention device for a manhole, comprising a fixing member that is freely fixed. 2. The manhole fall prevention device according to claim 1, wherein the body has a disc shape.