JP7266294B2 - Elevating safety fence for manholes - Google Patents

Description

The present invention relates to an elevating safety fence for manholes installed in manholes provided as passages for maintenance and inspection to underground facilities such as underground sewers and wiring facilities.

Generally, manholes are provided as passages for maintenance and inspection to underground facilities such as underground sewers and wiring facilities. Normally, the manhole opens to the ground surface of a road or the like, and the opening is provided with a cover plate made of cast iron that seals the vertical hole.

Maintenance and inspection of underground facilities is carried out by opening this heavy cover plate made of cast iron and entering the manhole, and normally the cover plate is left open during work. Therefore, workers on the ground or passers-by on the road or the like may accidentally fall into the manhole during work.

In order to prevent such falls, an elevating safety fence for manholes has been proposed in which a safety fence that can be freely raised and lowered is provided inside the manhole, and the safety fence is raised at the opening of the manhole during work. (See Patent Document 1, for example).

The elevating safety fence for manholes described in Patent Document 1 includes a ladder attached to the inner peripheral wall of the manhole, movable struts provided on both struts of the ladder so that they can be lifted and lowered, and a safety fence provided on the movable struts. , and a cover provided on the upper end of the safety fence, and the movable strut is lowered to store the safety fence in the manhole.

The safety fence consists of each movable pillar, a plurality of arc-shaped horizontal beams that are vertically spaced between the movable pillars, and a plurality of horizontal beams along each horizontal beam. It consists of vertical bars.

Since the elevating safety fence for manholes described in Patent Document 1 has a lid on the upper end of the safety fence, even if the cover plate of the manhole is removed, the lid of the safety fence prevents workers from falling into the manhole. can be prevented.

JP-A-9-279615

By the way, in the safety fence of the lifting type safety fence for manholes described in Patent Document 1, horizontal beams are formed in an arc shape along the opening of the manhole. This safety fence narrows the manhole opening.

If the opening of the manhole is narrow, it is necessary for workers to enter and exit the manhole opening in an unreasonable posture such as crouching down. There was a problem that it was difficult to

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an elevating safety fence for a manhole that can secure the opening of the manhole.

In order to solve the above problems, the manhole lifting safety fence according to the present invention is a ladder having two posts fixed to the inner peripheral wall of the manhole, and is attached so as to be able to go up and down along each of the posts. An elevating safety fence for manholes comprising a movable strut and a safety fence stretched between the movable struts,
In a state where the safety fence is at a position higher than the opening of the manhole, the movable struts can be held against the struts, and the safety fences are attached to the respective movable struts via a first hinge portion. and a second rail portion swingably connected via a second hinge portion so as to span between the first rail portions. , the second fence is formed by connecting a plurality of fences to each other via a third hinge so as to be able to swing, and when the safety fence is positioned higher than the opening of the manhole, the safety The fence has a folded state in which the first hinge portion, the second hinge portion, and the third hinge portion are positioned above the opening of the manhole, and a folded state in which the third hinge portion is positioned above the outer peripheral portion of the opening of the manhole. The safety fence can adopt a configuration in which the safety fence is arranged in the manhole in the folded state.

In this configuration, the safety fence is folded and placed inside the manhole before use. When in use, the movable strut is raised relative to the strut so that the safety fence is positioned higher than the opening of the manhole. When the safety fence is deployed, the plurality of fence bodies of the second fence can be positioned above the outer peripheral portion of the opening of the manhole.

The safety fence may employ a configuration in which the second hinge portion is positioned above the outer peripheral portion of the opening of the manhole in the deployed state.

With this configuration, in the unfolded state, the third hinge portion and the second hinge portion of the safety fence are positioned above the outer peripheral portion of the opening of the manhole, so a larger opening of the manhole can be ensured.

The post is formed of a cylindrical member having a slit extending in the vertical direction, the movable post has a protruding plate portion protruding from an outer peripheral portion, and the movable post is in a state in which the protruding plate portion protrudes from the slit of the post. A post is arranged inside the post, the protruding plate portion has a plurality of guide bodies fixed at intervals in the vertical direction, and at least one of the plurality of guide bodies is positioned on both sides of the slit of the post. Edge-contacting configurations can be employed.

In this configuration, since the guide body is in contact with both edges of the slit of the support, the projecting plate of the movable support can be prevented from swinging within the slit of the support.

By adopting a configuration in which the plurality of fences are two fences, when the safety fence is in a folded state, the two fences of the second fence are arranged near the central portion of the opening of the manhole. . These two fences can prevent workers from falling into the manhole.

In a configuration in which the plurality of fences are two fences, a lock bar having a hook on one of the first fence and the fence is swingably attached to the other. A receiver is attached to which the hook of the lock bar is detachably engaged, and when the safety fence is in the folded state or the unfolded state, the hook of the lock bar can be engaged with the receiver. configuration can be employed.

In this configuration, the safety fence is held in the folded or unfolded state by engaging the hooks of the lock bar with the receivers. Therefore, the safety fence can be smoothly moved up and down.

According to the present invention, since a part of the safety fence can be developed above the outer circumference of the opening of the manhole, the opening of the manhole is secured and workers can enter and exit the manhole without taking an unreasonable posture. be able to.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the elevating-type safety fence for manholes of 1st Embodiment which concerns on this invention. The perspective view which shows a folding state within the manhole of the lifting type safety fence for manholes same as the above. The top view which shows a folding state in the manhole of the lifting-type safety fence for manholes same as the above. The perspective view which shows the deployment state of the safety fence same as the above. The perspective view which shows a locking member same as the above. Partially cutaway plan view showing the strut and the movable strut same as the above Partially cutaway perspective view showing the strut and the movable strut same as the above Explanatory drawing showing the operation of the lock member same as the above The side view which shows a lock bar and a receiver same as the above. The top view which shows the deployment state of the safety fence same as the above The top view which shows the elevating-type safety fence for manholes of 2nd Embodiment which concerns on this invention.

A first embodiment of the present invention will be described below with reference to the drawings. 1 to 10 show an elevating safety fence for manholes according to a first embodiment of the present invention. This manhole liftable safety fence 1 is fixed to the inner peripheral wall of the manhole M and used when a worker enters the manhole M. As shown in FIG.

As shown in FIGS. 1 to 4, the manhole elevating safety fence 1 includes a ladder 10 having two pillars 11 fixed to the inner peripheral wall W of the manhole M, and a ladder 10 that can be raised and lowered along each pillar 11. It is provided with attached movable posts 12, 12 and a safety fence 20 stretched between the respective movable posts 12, 12. - 特許庁

The ladder 10 has two columns 11 arranged in the vertical direction, and a plurality of treads 11a bridged between the columns 11, 11 at intervals in the vertical direction. As shown in FIG. 3, each post 11 is formed from a long square tubular member, and has a rectangular cross section in the horizontal direction.

Each support 11 has an outer side surface 13 positioned near the peripheral edge of the manhole M, an inner side surface 14 facing the outer side 13, a ladder side 15 positioned on the ladder 10 side, and a ladder side 15 facing each other. , and a fence side portion 16 located on the safety fence 20 side.

The outer side portion 13 has a wider width than the ladder side portion 15 . Fixing metal fittings 2 are provided at the lower ends of the columns 11 and the upper ends of the inner side surfaces 14, respectively, and the respective columns 11 are fixed to the inner peripheral wall and the inner bottom wall of the manhole M by anchor bolts inserted through the fixing metal fittings 2.

The treads 11a are bridged between the ladder side portions 15 of the pillars 11 at predetermined intervals in the vertical direction. An engagement piece 14 a is provided at a position near the fence side portion 16 on the upper edge of the inner side portion 14 . The engaging piece 14a extends upward and engages with a hook 6a of the locking member 6, which will be described later. The fence side part 16 has the slit 16a formed in the up-down direction over the full length in the width direction center.

A pulley 3 is attached to the upper part of the column 11 . A shaft 3a is arranged between the outer side surface portion 13 and the inner side surface portion 14, and the pulley 3 rotates around the shaft 3a. A balance weight 4 is housed in the column 11 so as to be able to move up and down.

The ends of the wire 5 are joined to the balance weight 4 and the movable strut 12, respectively. A wire 5 is wound around the pulley 3 . The balance weight 4 in each strut 11 has a weight of half the total weight of each movable strut 12 and safety fence 20 .

The movable post 12 is an elongated cylindrical member, and has a protruding plate portion 12a that protrudes over the entire length from the outer peripheral portion of the cylindrical member. The protruding plate portion 12a protrudes from the slit 16a of the post 11 to the outside. The movable column 12 is arranged so as to be able to move up and down within the column 11 . Note that the movable strut 12 may be a solid rod-shaped member. If the movable strut 12 is a cylindrical member, weight reduction can be achieved.

When the safety fence 20 is positioned higher than the opening of the manhole M, the joining position of the wire 5 with the movable strut 12 is positioned lower than the pulley 3 . When the safety fence 20 is at a position lower than the opening of the manhole M, the joining position of the wire 5 with the balance weight 4 is at a position lower than the pulley 3.

As shown in FIGS. 5 to 7, the projecting plate portion 12a has a lock member 6 and a handle 12c attached to the surface on the inner side portion 14 side. The handle 12c is arranged outside the locking member 6 in the projecting direction of the projecting plate portion 12a.

As shown in FIG. 1, a regulating member 17 is hung between the handles 12c. The restricting member 17 is formed of a chain, a rope, or the like, and is detachably attached to one of the handles 12c. The restricting member 17 restricts entry into the manhole by persons other than workers.

The lock member 6 is formed of a shaft-like member and is rotatably supported via two support pieces 12b fixed to the upper portion of the projecting plate portion 12a with a space therebetween in the vertical direction. A right-angled hook 6a is provided at the lower end of the lock member 6, and a right-angled lever 6b is fixed to the upper end of the lock member 6. As shown in FIG. An upper stopper ring 6 c and a lower stopper ring 6 d are fixed to the outer peripheral portion of the lock member 6 .

The lock member 6 passes through the two support pieces 12b. The upper stopper ring 6c is placed on the upper support piece 12b, and the lower stopper ring 6d is positioned directly below the lower support piece 12b.

As shown in FIG. 5 , a spring member 6 e is attached between the lock member 6 and the projecting plate portion 12 a of the movable support 12 . The spring member 6e has a helical spring, and biases the hook 6a toward the inner side surface portion 14 of the post 11 by the elastic restoring force of the helical spring. The positional relationship between the hook 6a and the lever 6b is set to 45 degrees to 60 degrees centered on the vertical intermediate portion of the lock member 6 in plan view.

When the movable strut 12 is raised and the safety fence 20 is at a position higher than the opening of the manhole M, the hook 6a of the lock member 6 rests on the upper end surface of the strut 11 and engages with the engaging piece 14a. there is As a result, as shown by the solid line in FIG. 8, the movable column 12 is restricted from being lowered, and the movable column 12 is held with respect to the column 11 .

A plurality of (two in this embodiment) guide bodies 7 are fixed to the projecting plate portion 12a at intervals in the vertical direction. The upper guide body 7 is arranged above the lever 6 b of the lock member 6 , and the lower guide body 7 is arranged below the hook 6 a of the lock member 6 .

As shown in FIGS. 6 and 7, each guide body 7 is formed of a pair of rectangular resin plate pieces 7a. A pair of plate pieces 7a are fixed to the protruding plate portion 12a while being sandwiched by bolts and nuts from both sides of the protruding plate portion 12a.

The end edges of the pair of plate pieces 7a on the support 11 side are linearly in contact with both edges of the slit 16a. The guide body 7 restricts the swinging motion of the projecting plate portion 12a within the slit 16a of the post 11. As shown in FIG. The number of guide bodies 7 may be three, four, and so on. It is sufficient that at least one guide body 7 is in contact with both edges of the slit 16a of the post 11. As shown in FIG.

As shown in FIG. 1, the safety fence 20 includes two first fence portions 21 that are swingably connected to the respective movable struts 12 via the first hinge portions 22, and and a second fence portion 23 that is swingably connected via a second hinge portion 24 so as to bridge between the portions 21 .

As shown in FIG. 2, each first fence 21 is a rectangular frame member. A middle crosspiece 21a is horizontally arranged in the center portion of the first rail portion 21 in the vertical direction. A handle 21 b is attached to the upper portion of the first rail portion 21 . The handle 21 b is vertically movable between a position higher than the upper end surface of the first rail portion 21 and a position lower than the upper end surface of the first rail portion 21 .

As shown in FIG. 4, the first hinge portion 22 consists of a top hinge portion 22a and a bottom hinge portion 22b. The hinge shafts of the first hinge portion 22 are arranged on the same straight line in the vertical direction. A known pair of upper and lower cabinet hinges can be used for the first hinge portion 22 .

The top hinge portion 22 a is arranged between the upper end portion of the projecting plate portion 12 a and the upper end portion of the first rail portion 21 . The bottom hinge portion 22 b is arranged between the middle position in the vertical direction of the projecting plate portion 12 a and the lower end portion of the first rail portion 21 .

The hinge shafts of the top hinge portion 22a and the bottom hinge portion 22b are provided between the projecting plate portion 12a of the movable strut 12 and the first rail portion 21, but apart from them. The first fence portion 21 swings horizontally with respect to the movable strut 12 .

The second fence portion 23 is formed by connecting a plurality of (two in this embodiment) fence bodies 23a and 23b to each other via a third hinge portion 25 so as to be able to swing. The fences 23a and 23b are the same rectangular frame members as the first fence 21. As shown in FIG. The number of fence bodies of the second fence portion 23 is not limited to two as long as it is plural, and may be three, four, five, and so on.

One of the two first rail portions 21 and the rail body 23a are connected to each other through a second hinge portion 24 so as to be horizontally swingable. Similarly, the other first fence portion 21 and the fence body 23b are connected to each other through the second hinge portion 24 so as to be horizontally swingable.

The second hinge portion 24 consists of a top hinge portion 24a and a bottom hinge portion 24b. The hinge shafts of the second hinge portion 24 are arranged on the same straight line in the vertical direction. The second hinge portion 24 can use a known pair of upper and lower butterfly hinges.

A top hinge portion 24a is attached to an upper portion between the widthwise outer end surface of one first rail portion 21 and the widthwise outer end surface of the rail body 23a. The bottom hinge portion 24b is attached to the lower portion between the widthwise outer end surface of one first rail portion 21 and the widthwise outer end surface of the rail body 23a. Similarly, a top hinge portion 24a and a bottom hinge portion 24b are attached between the other first rail portion 21 and the rail body 23b. The hinge shaft of the second hinge portion 24 is positioned inside the first fence portion 21 (inside the safety fence 20 in the unfolded state).

The third hinge portion 25 consists of a top hinge portion 25a and a bottom hinge portion 25b. The hinge shafts of the third hinge portion 25 are arranged on the same straight line in the vertical direction. The third hinge portion 25 can use a known pair of upper and lower pivot hinges or cabinet hinges.

The hinge shaft of the third hinge portion 25 is positioned away from the fences 23a and 23b and outside the fences 23a and 23b when the safety fence 20 is deployed.

A lock bar 8 is attached to the inner side of the upper end of each first rail portion 21 so as to be able to swing. A receiver 9 is attached to the inner side of the upper ends of the rails 23a and 23b.

The lock bar 8 is formed by bending a shaft-like member. Both ends of the lock bar 8 are bent at right angles in the same direction, and a hook 8a is formed at one bent portion and a shaft portion 8b is formed at the other bent portion. The hook 8a is shorter than the shank 8b.

A shaft portion 8b of the lock bar 8 is rotatably supported by a support piece 8c fixed to the first rail portion 21 . A stopper ring 8d is fixed to the lower end of the shaft portion 8b. The stopper ring 8d prevents the lock bar 8 from slipping out of the support piece 8c.

The receiver 9 is a plate member whose longitudinal central portion is curved, and the hook 8a of the lock bar 8 is detachably engaged with the curved portion 9a from above.

As shown in FIG. 3, when the safety fence 20 is in the folded state, the lock bar 8 of one of the two first fences 21 receives the fence 23b that is not adjacent to the one of the first fences 21. It engages the tool 9. The lock bar 8 of the other first rail portion 21 engages with the receiver 9 of the rail body 23a that is not adjacent to the other first rail portion 21 .

Due to this engagement, the first fence portion 21 and the fence body 23b, which are not adjacent to each other, are held so as to straddle the fence body 23a so as not to swing. In addition, the other first fence portion 21 and the fence body 23a that are not adjacent to each other straddle the fence body 23b and are held so as not to swing. That is, the lock bar 8 holds the safety fence 20 in a folded state.

On the other hand, as shown in FIG. 4, when the safety fence 20 is in the unfolded state, the lock bar 8 of one of the two first fences 21 is positioned on the fence body 23a adjacent to the one of the first fences 21. It engages the receiver 9 . In addition, the lock bar 8 of the other first rail portion 21 engages with the receiver 9 of the rail body 23b adjacent to the other first rail portion 21. As shown in FIG.

Due to this engagement, the first fence portion 21 and the fence body 23a adjacent to each other are held so as not to swing. Further, the other first fence portion 21 and the fence body 23b adjacent to each other are held so as not to swing. That is, the lock bar 8 holds the safety fence 20 in the unfolded state.

In this embodiment, the lock bars 8 may be attached to the fences 23a and 23b of the second fence 23, and the receivers 9 may be attached to the two first fences 21, respectively.

When the safety fence 20 is positioned higher than the opening of the manhole M, the safety fence 20 is in a folded state in which the first hinge portion 22, the second hinge portion 24 and the third hinge portion 25 are positioned above the opening of the manhole. and a deployed state in which the second hinge portion 24 and the third hinge portion 25 are positioned above the outer peripheral portion of the opening of the manhole M.

As shown in FIG. 3, when the safety fence 20 is folded, the two fences 23a and 23b of the first fence 21 and the second fence 23 are positioned above the opening of the manhole M. As shown in FIG. On the other hand, as shown in FIG. 10, when the safety fence 20 is deployed, the fences 23a and 23b of the second fence 23 are positioned above the outer periphery of the manhole M opening.

The elevating safety fence 1 for manholes of this embodiment is configured as described above. Next, a method for using the manhole liftable safety fence 1 will be described.

First, as shown in FIG. 2, before use, each movable strut 12 is at a position lower than the opening of the manhole M, and the safety fence 20 is at a position lower than the opening of the manhole M and in a folded state. At this time, the balance weight 4 is in a state of being pulled up to the highest position within the strut 11 .

Next, the worker P removes the cover (not shown) of the manhole M. At this time, the lock bar 8 holds the safety fence 20 in a folded state. As shown in FIG. 3, when the safety fence 20 is folded, the fence bodies 23a and 23b of the second fence portion 23 are arranged along the diameter of the manhole M. As shown in FIG. Therefore, it is possible to prevent workers from falling into the manhole M.

Subsequently, the handle 21b of each first fence portion 21 is grasped, and the two movable struts 12 are lifted together with the safety fence 20.例文帳に追加At this time, the balance weight 4 can be lifted with a relatively light force.

Here, the hook 6a of the lock member 6 is biased toward the inner side surface portion 14 of the post 11. As shown in FIG. Therefore, the hook 6a rises while contacting the support 11. As shown in FIG.

Further, when the movable column 12 is raised, the hook 6a climbs over the engaging piece 14a of the column 11 and comes into contact with the movable column 12. As shown in FIG. After that, by lowering the movable column 12, the hook 6a is placed on the upper end surface of the column 11. As shown in FIG.

In this state, the safety fence 20 is positioned higher than the opening of the manhole M. At this time, even if the lever 6b of the lock member 6 is rotated, the hook 6a is engaged with the engaging piece 14a. With this lock member 6 , the movable support 12 can be held against the support 11 in a state where the safety fence 20 is positioned higher than the opening of the manhole M.

Next, the lock bar 8 is extracted from the receiver 9 and the safety fence 20 is deployed. After that, the hook 8a of the lock bar 8 is engaged with the receiver 9, and the gap between one first rail portion 21 and the rail body 23a adjacent to the one first rail portion 21 and the other first rail portion 21 and the fence body 23b adjacent to the other first fence portion 21 are held so as not to swing. As a result, the safety fence 20 is held in the unfolded state.

In this unfolded state, the second hinge portion 24 and the third hinge portion 25 of the safety fence 20 are positioned above the outer peripheral portion of the opening of the manhole M. That is, the fences 23a and 23b of the second fence 23 are positioned above the outer peripheral portion of the manhole M opening.

Due to this positional relationship, as shown in FIG. 10, the worker P can move up and down the ladder 10 with a gap between his shoulders and the safety fence 20, thereby ensuring a larger opening of the manhole M. can do.

After confirming that the safety fence 20 is held in the unfolded state, the worker P descends into the manhole using the ladder 10, and performs work such as maintenance and inspection of the wiring equipment of the sewage system and underground facilities, for example. .

While the worker P is working underground, the restricting member 17 is hung between the handles 12c of the movable struts 12 to restrict the entry of passers-by into the manhole M.

After finishing the work, the worker P who has climbed up to near the ground with the ladder 10 removes the restricting member 17 and goes out to the ground through the opening of the manhole M. After that, the worker P removes the hook 8a of the lock bar 8 from the receiver 9 and folds the safety fence 20.例文帳に追加

To fold the safety fence 20 , first, the third hinge portion 25 is moved toward between the two movable supports 12 while the second hinge portion 24 is moved above the opening of the manhole M. Further, the fence body 23a and the fence body 23b of the second fence portion 23 are overlapped. In this state, the hooks 8a of the respective lock bars 8 are inserted into the receivers 9 to hold the safety fence 20 in the folded state.

Subsequently, as shown by the dashed line in FIG. 8, the handle 21b is held and the safety fence 20 is slightly lifted. In this state, the lever 6b of the locking member 6 of each movable support 12 is rotated toward the first rail portion 21. As shown in FIG.

Rotation of the lever 6b causes the hook 6a to rotate. The hook 6a is disengaged from the upper end surface of the post 11 in a plan view and disengaged from the engaging piece 14a. At this time, the handle 21b is held and the safety fence 20 is lowered to a position lower than the opening of the manhole M. Finally, a lid is fitted to the opening of the manhole M to complete the work.

The manhole elevating safety fence 1 used in this manner can deploy the two fence bodies 23a and 23b of the second fence portion 23 of the safety fence 20 above the outer peripheral portion of the opening of the manhole M. . Therefore, the opening of the manhole M is secured, and the worker P can enter and exit the manhole without taking an unreasonable posture.

Next, FIG. 11 shows an elevating safety fence for manholes according to a second embodiment of the present invention. In the manhole lift type safety fence 1 of this embodiment, the second fence portion 23 is composed of four fence bodies, ie, a fence body 23a, a fence body 23b, a fence body 23c and a fence body 23d, and the safety fence 20 is deployed. This differs from the above-described first embodiment in that the second hinge portion 24 is positioned above the opening of the manhole M in this state. Configurations similar to those of the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

As shown by the dashed line in FIG. 11, in the manhole elevating safety fence 1 of this embodiment, the first fence portion 21 has a smaller width in the horizontal direction than the first fence portion of the first embodiment. are using.

The fence 23a, the fence 23b, the fence 23c, and the fence 23d of the second fence portion 23 are rectangular frame members of the same size, and are connected to each other via the third hinge portion 25 so as to be able to swing. ing. One of the two first rail portions 21 and the rail body 23a are connected via a second hinge portion 24 so as to be swingable to each other. The other first rail portion 21 and the rail body 23d are connected to each other through the second hinge portion 24 so as to be swingable.

The first hinge portion 22 in the second embodiment is positioned above the opening of the manhole M in the folded state of the safety fence 20 (see the dashed-dotted line in FIG. 11). On the other hand, as shown by the solid line in FIG. 11, only the third hinge portion 25 is located above the outer peripheral portion of the opening of the manhole M when the safety fence 20 is deployed.

In the second embodiment, when the safety fence 20 is deployed, the fences 23c and 23d of the second fence 23 are positioned above the outer periphery of the manhole M opening. Therefore, during work, the worker P can ascend and descend the ladder 10 with a gap between his shoulders and the safety fence 20, and a larger opening of the manhole M can be ensured.

1 Elevating type safety fence for manhole 2 Fixing bracket 3 Pulley 4 Balance weight 5 Wire 6 Lock member 6a Hook 6b Lever 6e Spring member 7 Guide body 7a Plate piece 8 Lock bar 8a Hook 9 Receiver 10 Ladder 11 Post 12 Movable post 12a Protrusion Plate 13 Outer side 14 Inner side 14a Engaging piece 15 Ladder side 16 Fence side 16a Slit 17 Regulating member 20 Safety fence 21 First fence 22 First hinge 23 Second fence 23a, 23b, 23c, 23d Rail body 24 Second hinge portion 25 Third hinge portion M Manhole P Worker W Inner peripheral wall

Claims (5)

a ladder (10) having two posts (11) fixed to the inner peripheral wall of the manhole;
An elevating safety fence for manholes, comprising a movable support (12) attached so as to be able to move up and down along each of the supports (11), and a safety fence (20) stretched between the respective movable supports (12). ,
said movable strut (12) can be held against said strut (11) with said safety fence (20) positioned higher than said manhole opening;
a first fence (21) to which the safety fence (20) is pivotably connected to each of the movable struts (12) via a first hinge (22); and each of the first fences. a second rail section (23) swingably connected via a second hinge section (24) so as to span between the sections (21);
The second fence (23) is formed by connecting a plurality of fences to each other via a third hinge (25) so as to be able to swing,
When the safety fence (20) is at a position higher than the opening of the manhole, the safety fence (20) includes the first hinge part (22), the second hinge part (24) and the third hinge part ( 25) is positioned above the opening of the manhole, and the third hinge part (25) is positioned above the outer peripheral portion of the opening of the manhole.
An elevating safety fence for a manhole, wherein the safety fence (20) is arranged in the manhole in the folded state. 2. The manhole according to claim 1, wherein the safety fence (20) has the second hinge portion (24) located above the outer peripheral portion of the opening of the manhole in the unfolded state. Elevating safety fence. The strut (11) is formed of a cylindrical member having a slit (16a) extending in the vertical direction, and the movable strut (12) has a protruding plate portion (12a) protruding from the outer peripheral portion,
The projecting plate portion (12a) protrudes from the slit (16a) of the post (11), and the movable support post (12) is arranged in the support post (11). has a plurality of guide bodies (7) fixed at intervals in the vertical direction, and at least one of the plurality of guide bodies (7) is at both edges of the slit (16a) of the support (11) 3. The elevating safety fence for manholes according to claim 1 or 2, wherein the manhole safety fence is in a state of being in contact with the . The elevating safety fence for a manhole according to any one of claims 1 to 3, wherein the plurality of fences are two fences (23a, 23b). A lock bar (8) having a hook (8a) is swingably attached to one of the first fence (21) and the fence, and the hook of the lock bar (8) is attached to the other. (8a) is detachably engaged with a receiver (9), and when the safety fence (20) is in the folded state or the unfolded state, the hook (8a) of the lock bar (8) is A liftable safety fence for a manhole according to claim 4, characterized in that it is engageable with said receiving device (9).

Images