JP7493777B2 - Safety fence - Google Patents

Description

The present invention relates to a safety fence that separates a work area from an area for third-party passage during construction of an opening such as a manhole, ensuring the safety of both. It also relates to safety fences for openings at construction sites.

Safety fences are used to prevent pedestrians from falling during manhole construction (for example, as disclosed in Patent Document 1).
8 is an explanatory diagram of a conventional safety fence. As shown in the figure, a conventional safety fence 1 is composed of four legs 2 arranged at the four corners of a rectangle in a plan view surrounding an opening such as a manhole, and a pantograph mechanism 3 connected between the legs 2 and to which multiple X-shaped links are linked. In this type of safety fence 1, the pantograph mechanism 3 between the legs 2 expands and contracts like a bellows, so that when the safety fence 1 is in an extended state, it can be formed into a fence-like shape that surrounds the opening. On the other hand, when the safety fence 1 is in a contracted state, the four legs 2 are close to each other and folded up, making it easy to carry.

However, while conventional safety fences are made of metal and are durable, when an object comes into contact with them, the pantograph mechanism expands and contracts, causing the legs to easily tilt, making them unstable and creating problems with strength. Furthermore, although conventional safety fences are durable, they are heavy and difficult to carry manually.

JP 2017-36547 A

In view of the problems of the conventional technology described above, the problem that the present invention aims to solve is to provide a safety fence that has a simple structure, is easy to assemble, is stable when installed, and is easy to carry.

As a first means for solving the above problems, the present invention provides a fence body having a plurality of legs, an upper cross member having a two-fold structure connected between the upper legs of the legs, an X-link having an upper end connected to the upper cross member and a lower end connected between the lower legs, and a pantograph mechanism consisting of a lower cross member having a two-fold structure connected below the X-link, which extends in an accordion-like manner to surround an opening;
A lower reinforcing frame that fixes the legs of the fence body that is expanded into a fence shape surrounding the opening;
An upper reinforcing bar that is fixed so as to intersect with the upper cross member of the fence body that is expanded into a fence shape surrounding the opening;
having
The objective of the present invention is to provide a safety fence in which the upper reinforcing bar and the lower reinforcing frame have a folding structure in which a plurality of rod-shaped members are foldably connected, and a joint structure is provided at the ends to cross and connect the ends of the plurality of connected rod-shaped members.
According to the first means, even with a simple structure of three members, the fence is stable when installed. When the fence body is fixed with the upper reinforcing bar, a truss structure is formed, ensuring a certain level of strength. All members can be folded, making it easy to carry. After the folded upper reinforcing bar and lower reinforcing frame are unfolded and connected into a frame shape, they do not easily bend, and a certain level of strength can be maintained.

As a second means for solving the above problem, the present invention provides a safety fence as described in the first means, characterized in that the upper reinforcing bar has a clip or fastening means that is fitted into the opposing upper cross member when the upper cross member is fixed.
According to the second means described above, the upper reinforcing bar can be easily fixed to or detached from the fence body, and a predetermined strength can be maintained.

As a third means for solving the above problems, the present invention provides a safety fence as described in the first means, characterized in that the fence main body has a detachable portion that allows the upper end of the X-link of the pantograph mechanism on any one side and the joint of the upper cross member to be removed.
According to the third means described above, an entrance and exit for workers can be easily provided on the side of the fence body which is expanded into a fence shape.

As a fourth means for solving the above problems, the present invention provides a safety fence which, in the first means, is characterized in that when the fence main body is expanded into a fence-like shape surrounding the opening, the length between the lower ends of the X-shaped links is set longer than the length of the upper cross member.
According to the fourth means described above, the opening area of the upper surface of the fence body is smaller than that of the lower surface, so that it can be formed into a pyramid or quadrangular pyramid shape, forming a truss structure and ensuring stability when installed.

The present invention makes it possible to realize a safety fence that is simple in structure, easy to assemble, strong, stable when installed, lightweight, compact, and easy to carry.

FIG. 2 is a side view of the safety fence of the present invention. FIG. 2 is a plan view of the safety fence of the present invention. FIG. FIG. FIG. 13 is an explanatory diagram of the fence body in a folded state. An explanatory diagram showing the fence body being unfolded. This is an explanatory diagram of the entrance and exit of the safety fence. FIG. 1 is an explanatory diagram of a conventional safety fence.

An embodiment of a safety fence according to the present invention will be described in detail below with reference to the drawings.
[Safety fence 10]
Fig. 1 is a side view of the safety fence, Fig. 2 is a plan view of the safety fence, and Fig. 3 is an explanatory diagram of the joint structure.
The safety fence 10 has a fence main body 20 having multiple legs 22, with a pantograph mechanism 24 between the legs 22 extending accordion-like to surround an opening, a lower reinforcing frame 30 that secures the legs 22 of the fence main body 20 which has been expanded into a fence-like shape surrounding the opening, and an upper reinforcing bar 40 that is fixed so as to intersect with an upper cross member 26 of the fence main body 20 which has been expanded into a fence-like shape surrounding the opening.

The fence body 20 is a fence that surrounds (encloses) the opening, and has four legs 22 and a pantograph mechanism 24 that is arranged between the legs 22 and expands and contracts like an accordion. The pantograph mechanism 24 is arranged between the four legs 22, in other words, on each of the four sides (front, left and right sides, and back). The specific structure of the pantograph mechanism 24 consists of an upper cross member 26, an X-shaped link 27, and a lower cross member 28.

The upper cross member 26 employs a link mechanism (two-fold structure) in which two links are rotatably connected by a joint, and both ends are connected to the upper part of the legs 22 (between the upper legs) via joints.
The X-shaped link 27 is a diagonal brace consisting of two links crossed in an X shape, with its upper end rotatably connected to the upper cross member 26 (each of its two links) via a joint, and its lower end rotatably connected to the lower part of the leg 22 (between the lower leg parts) via a joint.
Similar to the upper cross member 26, the lower cross member 28 employs a link mechanism (two-fold structure) in which two links are rotatably connected by a joint, and is rotatably connected to the lower part of the X-link 27 via a joint.
In addition, when the fence body 20 is expanded into a fence shape surrounding the opening, the length between the lower ends of the X-shaped links 27 is set longer than the length of the upper cross member 26.

When the pantograph mechanism 24 between the legs 22 of the fence body 20 having the legs 22 and the pantograph mechanism 24 configured as described above is extended, the upper cross member 26 and the lower cross member 28 extend linearly, and when the X-links 27 also expand, the upper ends of the legs 22 are tilted inward more than the lower ends, forming a trapezoid in side view. In other words, the rectangle connecting the upper ends of the legs 22 is smaller than the rectangle connecting the lower ends of the legs 22, forming a pyramid or square pyramid shape. Therefore, multiple truss structures are formed within the pantograph mechanism 24. This increases the strength and improves stability when installed.

The lower reinforcing frame 30 and the upper reinforcing bar 40 employ a folding structure in which a number of rod-shaped members are rotatably connected via joints.
The specific configuration of the lower reinforcing frame 30 uses a member having a surface perpendicular (extending vertically) to the ground or floor surface, such as an angle iron (equal leg angle iron). The length of this member is set to be slightly longer than the length between the lower ends of the legs 22 when the fence body 20 is unfolded. In the lower reinforcing frame 30 of this embodiment, four angle irons, the same number as the legs 22, are arranged in a rectangular frame shape in a plan view. In this case, the diagonal corners (opposing corners) of the lower reinforcing frame 30 use a joint 30a and a joint structure 30b. The joint 30a can be any joint that can fold two angle irons, and can be, for example, a hinge. The joint structure 30b can be any joint that can join the intersecting angle irons at right angles (see FIG. 3(1)).
Such a lower reinforcing frame 30 is made up of two angle members connected by joints 30a, with joint structures 30b formed at both ends. The two members are arranged in a square shape in plan view. When the joint structures 30b are fitted together, the four corners of the lower reinforcing frame 30 are held at right angles. At this time, the lower ends of the legs 22 come into contact with the inside of the four corners of the lower reinforcing frame 30 when the fence body 20 is spread out, providing strong support.

Specifically, the upper reinforcement bar 40 uses flat steel. The length of the flat steel is set to be equal to or longer than the length of the upper cross member 28. In this embodiment, the upper reinforcement bar 40 is arranged in a rectangular frame shape in a plan view, with four flat steel pieces, the same number as the legs 22. In this case, the diagonal corners (opposing corners) of the upper reinforcement bar 40 use a joint 40a and a joint structure 40b. The joint 40a can be any joint that allows two flat steel pieces to be folded, and a hinge, for example, can be used. The joint structure 40b can be any joint that allows the intersecting flat steel pieces to be joined at right angles (see FIG. 3(2)).
The upper reinforcing bar 40 is made of two flat steel pieces connected by joints 40a, with joint structures 40b formed at both ends. The two pieces are arranged in a square shape in a plan view. When the joint structures 40b are fitted together, the four corners of the upper reinforcing bar 40 are held at right angles.
When the upper reinforcing bar 40 is fixed on the upper cross member 26 of the fence body 20 that is spread out like a fence surrounding the opening, it is fixed so that it intersects with the longitudinal direction of the upper cross member 26, in other words, so that the four corners do not overlap with the legs 22. At this time, the upper reinforcing bar 40 is provided with a clip 50 or fastening means at a location facing the upper cross member 26. FIG. 4 is an explanatory diagram of a clip. The clip 50 is wedge-shaped (inverted U-shaped) and can be inserted into the upper cross member 26 to be fixed, and a grating clip or the like can be applied. In addition to the clip 50, any other configuration that can fix the upper reinforcing bar 40 to the upper cross member 26 can be used, and fastening means such as bolts and nuts, clamps, etc. can also be applied.

[Action]
The operation of the safety fence 10 of the present invention having the above-mentioned configuration will be described below.
5 is an explanatory diagram of the fence body folded up. As shown in the figure, when the pantograph mechanism 24 of the fence body 20 is contracted, the legs 22 are brought closer to the center and gathered together, and when the attached band 23 provided at the center of the legs 22 is wrapped around the outer periphery, it is packed up compactly, and using the handle 25 provided on the upper cross member 26 makes it easy to carry. It also becomes easier to store. Similarly, the upper reinforcing bar 40 and the lower reinforcing frame 30 can also be folded up and wrapped with a band to pack up compactly and make it easy to carry.
6 is an explanatory diagram of the fence body being unfolded. As shown in the figure, each pantograph mechanism 24 arranged on the four sides of the fence body 20 is extended. When the upper cross member 26 and the lower cross member 28 are linearly extended and the X-link 27 is also unfolded, the upper ends of the legs 22 are inclined inward more than the lower ends, forming a trapezoidal shape in side view.
The lower reinforcing frame 30 is made up of two angle members connected by joints 30a, with joint structures 30b formed at both ends, and these two members are arranged in a square shape in a plan view. When the joint structures 30b are fitted together, the four corners of the lower reinforcing frame 30 are held at right angles. At this time, the lower ends of the legs 22 come into contact with the inside of the four corners of the lower reinforcing frame 30 when the fence body 20 is spread out, providing strong support.

The upper reinforcement bar 40 is made up of two flat steel pieces connected by joints 40a, with joint structures 40b formed at both ends, and these two pieces are arranged in a square shape in a plan view. When the joint structures 40b are fitted together, the four corners of the upper reinforcement bar 40 are held at right angles. When the upper reinforcement bar 40 is fixed to the upper cross member 26 of the fence body 20, which is spread out like a fence surrounding the opening, it is fixed so that it intersects with the longitudinal direction of the upper cross member 26, in other words, so that the four corners do not overlap with the legs 22.
The upper reinforcing bar 40 can be secured by hooking a safety belt for the worker. This allows the safety belt to be connected to a strong safety fence, ensuring the safety of the worker. A ring for attaching the safety belt may also be attached.
In this type of safety fence 10, multiple truss structures are formed within the pantograph mechanism 24 of the fence body 20, which is trapezoidal (pyramidal or quadrangular cone) in side view, and the upper cross member 26, which is fixed by the upper reinforcing bar 40. This increases the strength and improves stability when installed. In addition, the simple structure makes it easy to assemble, and it is lightweight and compact, making it easy to carry.

FIG. 7 is an explanatory diagram of the entrance and exit of the safety fence.
The fence body 20 has a removable attachment part 60 at the joint between the upper end of the X-link 27 of the pantograph mechanism 24 on one side and the upper cross member 26. The attachment part 60 may have any structure as long as it allows a rotatable joint to be removed, and a thumbscrew may be used as one example. With such a configuration of the safety fence 10 equipped with the attachment part 60, after the safety fence 10 is installed surrounding the opening, the attachment part 60 can be used to release the connection between the upper cross member 26 and the X-link 27, thereby easily providing an entrance and exit for workers on the side of the fence body 20.

The shape of the fence body 20 in this embodiment has been described as a rectangle with four legs 22, but is not limited to this and may have three or five or more legs 22.
Furthermore, the safety fence of the present invention can be applied to other openings and objects to be prevented from approaching other than manholes.
Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and various modifications can be made without departing from the spirit and scope of the present invention.
Furthermore, the present invention is not limited to the combinations shown in the embodiments, but can be implemented in various combinations.

Reference Signs List 1 Safety fence 2 Leg 3 Pantograph mechanism 10 Safety fence 20 Fence body 22 Leg 23 Band 24 Pantograph mechanism 25 Handle 26 Upper cross member 27 X-link 28 Lower cross member 30 Lower reinforcing frame 30a Joint 30b Joint structure 40 Upper reinforcing bar 40a Joint 40b Joint structure 50 Clip 60 Detachable part

Claims (4)

a fence body having a plurality of legs, an upper cross member having a two-fold structure connected between the upper legs between the legs, an X-link having an upper end connected to the upper cross member and a lower end connected between the lower legs, and a pantograph mechanism consisting of a lower cross member having a two-fold structure connected below the X-link, which extends in an accordion-like manner to surround an opening;
A lower reinforcing frame that fixes the legs of the fence body that is expanded into a fence shape surrounding the opening;
An upper reinforcing bar that is fixed so as to intersect with the upper cross member of the fence body that is expanded into a fence shape surrounding the opening;
having
This safety fence is characterized in that the upper reinforcing bar and the lower reinforcing frame have a folding structure in which a plurality of rod-shaped members are foldably connected, and a joint structure is provided at the ends to cross and connect the ends of the connected rod-shaped members. 2. The safety fence according to claim 1,
A safety fence characterized in that the upper reinforcement bar has a clip or fastening means that is fitted to the opposing upper cross member when the upper cross member is fixed. 2. The safety fence according to claim 1,
A safety fence characterized in that the fence body has a detachable portion that allows the upper end of the X-shaped link of the pantograph mechanism on any one side and the joint between the upper cross member to be removed. 2. The safety fence according to claim 1,
A safety fence characterized in that when the fence body is expanded into a fence shape surrounding the opening, the length between the lower ends of the X-shaped links is set longer than the length of the upper cross member.

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