JP2000038888A - Ladder for manhole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the safety of a ladder for manhole to be set at a manhole of an underground structure such as conduit line system and set the ladder freely. SOLUTION: A ladder body consisting of two vertical side supports 21, 21 and a plurality of rungs 24, 24 is fixed on a bottom panel 11 of an underground structure 10 through lower end fixing parts 25, 25, while the ladder body is fixed to an interior wall 12 (or underside of upper panel 13) through upper side fixing members 28, 28, whereby the body is set under a manhole 14. Handrail members 26, 26 are slidably mounted to the top ends of the supports 21, 21, respectively, so that each of the members 26 is protruded from the manhole and retracted therefrom. An engaging groove comprising a vertical part and a horizontal part and an engaging means having an engaging protrusion which is slidably engaged in the engaging groove are provided in each of the members 26 and the corresponding support 21 respectively so that the handrail member 26 is engaged in its lowered state or in its lifted state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manhole ladder for a worker performing an inspection or the like to enter or leave a manhole in an underground structure such as a pipeline facility.

[0002]

FIG. 6 is a side elevational view of a conventional manhole ladder. The underground structure 10 such as a pipeline facility includes a bottom plate 1
1, a basement space consisting of an inner wall 12 and an upper plate 13 is provided, and a manhole 14 is provided in the upper plate 13 so that workers who perform inspections and the like enter and leave the manhole 14 in the basement space. I have. In addition, the manhole 14
Normally, when no inspection or the like is performed, it is closed by the lid 15.

On the inner wall 12, a plurality of U-shaped footrest members 4, 4,...
2 and are arranged side by side so as to protrude laterally from the inner wall 12 and form a ladder with these footrest members 4, 4,.... A U-shaped handrail member 6 is provided on the upper surface of the upper plate 13 (the floor surface outside the underground structure 10).
However, there is also a case where a tip portion is embedded in a concrete upper plate 13 and is installed so as to protrude upward from the upper plate 13.

[0004]

The above-mentioned footrest members 4, 4
If the handrail member 6 is not installed, the ladder is not able to support the body by hand when entering and exiting the manhole 14, and it is difficult to ensure safety. On the other hand, if the handrail member 6 is provided outside, there is a problem that the handrail member 6 becomes a hindrance at the time of normal inspection or the like.

Further, since the footrest members 4, 4,... Are buried in the inner wall 12, the manhole 14 needs to be arranged adjacent to the inner wall 12, and the arrangement of the manhole 14 is limited. Also, the footrest members 4, 4
It is difficult to accurately bury the mold, and the mold of the inner wall 12 cannot be diverted, and there is a problem that it takes time to disassemble the mold.

In view of the above problems, the present invention provides a manhole ladder that can be suitably installed in a manhole of an underground structure such as a pipeline facility and that allows a worker to safely move up and down. The purpose is to do.

[0007]

SUMMARY OF THE INVENTION A feature of the present invention is that a ladder body comprising two vertical columns and a plurality of horizontal columns is provided.
It is installed in a manhole of an underground structure, and a handrail member is mounted on an upper end portion of the column so as to be able to ascend and descend so as to protrude and retreat from the manhole.

The handrail member is vertically slidably mounted on an upper end portion of the support, and the handrail member and the support are provided with engaging means for locking the handrail member in a lowered state or a raised state. Is preferred. Further, in this case, the engagement means includes an engagement groove including a vertical portion and a horizontal portion,
It is preferable to include an engaging projection slidably engaged with the engaging groove.

[0009]

1 and 2 show a first embodiment of the present invention. FIG. 1A shows a ladder 20 for a manhole.
Side elevational view of a state in which the handrail members 26, 26 are lowered,
FIG. 1B is a front elevational view thereof, and FIG.
FIG. 4 is a side elevational view of a state in which the handrail members 26 are raised. 2A is an enlarged perspective view of a handrail member 26 in FIG. 1, and FIG. 2B is an exploded view thereof.

As shown in FIG. 1, an underground structure 10 such as a pipeline facility has an underground space composed of a bottom plate 11, an inner wall 12, and an upper plate 13. The upper plate 13 is provided with a manhole 14, Workers performing inspections and the like enter and leave the underground space from the manhole 14. It should be noted that the manhole 14 is normally covered with the cover 15
It is closed by A manhole ladder 20 is provided below the manhole 14.

The manhole ladder 20 is provided with a ladder body composed of two vertical columns 21, 21 and a plurality of horizontal bars 24, 24,.
Lower end fixing portions 25 are provided, and linear upper fixing members 28 are fixed to upper portions of the columns 21 so as to protrude laterally. And the pillars 21, 21
The handrail members 26, 26 are provided at the upper end portion of the manhole 1.
4 so as to be able to ascend and descend so as to protrude and retreat.

As shown in FIG. 2, the support 21 is formed in a pipe shape having an opening 22 at the upper end.
On the side surface of the upper end portion, an inverted L-shaped engagement groove 23 composed of a lower vertical portion 23a and an upper horizontal portion 23b is provided penetrating in and out. On the other hand, the handrail member 26 is formed in an inverted J-shape including a lower linear slide portion 26a and an upper inverted U-shaped protrusion 26b, and an engagement protrusion 27 is formed on the slide portion 26a. It is protruded.

The handrail member 26 has a sliding portion 26.
a is slidably inserted from the opening 22 into the upper end portion of the support 21, the engagement protrusion 27 is slidably engaged with the engagement groove 23, and the protrusion 26 b is located above the upper end of the support 21. It is attached to the upper end portion of the column 21 in a protruding form.

When the engagement projection 27 is engaged with the lower engagement position L at the lower end of the vertical portion 23a of the engagement groove 23,
The handrail member 26 is locked in a lowered state. From this state, lift the handrail member 26 upward,
The engagement protrusion 27 is moved to the upper end of the vertical portion 23 a of the engagement groove 23, and further, the handrail member 26 is rotated to the side, and the engagement protrusion 27 is moved to the tip of the horizontal portion 23 b of the engagement groove 23. When engaged with the upper locking position H, the handrail member 26 is locked in the raised state.

The tip of the lateral portion 23a of the engaging groove 23 is formed slightly downward, so that the engaging projection 27 is securely locked at the upper locking position H. When the engagement protrusion 27 is engaged with the lower locking position L, the protrusion 26b of the handrail member 26 faces in a direction parallel to the horizontal rails 24, 24,. The engaging groove 23 or the engaging protrusion 27 is arranged so that the protruding portion 26b faces in a direction perpendicular to the horizontal rails 24, 24,.

When the structure in which the handrail member 26 can be lifted and lowered by sliding the handrail member 26 with respect to the column 21 is simpler and more robust than a structure in which the handrail member is folded with respect to the column, for example. can do. Further, when the structure is such that the handrail member 26 is locked by the engagement groove 23 formed by the vertical portion 23a and the horizontal portion 23b and the engagement protrusion 27, the structure can be relatively simplified, and the handrail member 26 itself can be formed. Can be operated by moving the, so that the operation becomes easy. .

As shown in FIG. 1, the manhole ladder 20 has the lower end fixing portions 25, 25 fixed to the bottom plate 11 of the underground structure 10 by anchor bolts and the like, and the upper fixing members 28, 28 are connected to the underground structure. 10 is fixed to the inner wall 12 by an anchor bolt or the like and installed below the manhole 14. Then, when the handrail members 26, 26 are raised and lowered, they protrude and retreat from the manhole 14 up and down.

Therefore, when an operator performing an inspection or the like enters or exits the manhole 14, the handrail members 26 are protruded upward, so that the handrail members 26 are held by hand and safely moved up and down. On the other hand, at normal times when inspection or the like is not performed, the manhole 14 can be covered with the lid 15 by retracting the handrail members 26, 26 downward.

FIGS. 3 and 4 show a second embodiment in which the engaging means in the present invention is modified. The other parts are the same as those of the first embodiment, and the description thereof is omitted.

The engaging means in this embodiment includes an engaging projection 30 projecting from the handrail member 26 so as to be able to freely move in and out in the radial direction, and a locking means in which the engaging projection 30 is fitted when the handrail member 26 is pulled up. And a hole 31.
As shown in FIG. 4, the engagement protrusion 30 is fitted into the hole 32 on the outer peripheral surface of the handrail member 26 from the inside, and is urged in a protruding direction by a spring 33.

In the figure, reference numeral 34 denotes a retaining projection protruding from the handrail member 26, and reference numeral 35 denotes a retaining cap fixed to the column 21 to prevent the projection 34 from passing therethrough.

In this embodiment, the handrail member 26 is pushed into the support column 21 with the engagement projection 30 pushed in, and the engagement projection 30 is pulled up from this state so that the engagement projection 30 is locked.
By being directed to the position, the engaging projection 30 is pushed out by the pushing force of the spring 33 and is fitted into the locking hole 31, whereby the handrail member 26 is projected so as not to be pushed.

When the handrail member 26 is pushed in, the engagement is released by pushing the engagement projection 30 deeper than the locking hole 31 using a hand or a tool. In this state, the handrail member 26 is inserted into the support column 21. It is returned to the original state by pushing it.

FIG. 5 shows a third embodiment of the present invention.
It is a side elevation view in the state where the handrail members 26, 26 of the manhole ladder 20 were lowered. The description of the same parts as in the first embodiment is omitted, and the same reference numerals are used.

An L-shaped upper fixing member 29, 29 is fixed to the manhole ladder 20 near the upper end of the column 21, 21 so as to protrude upward.
Reference numeral 0 denotes a manhole 1 in which the upper fixing members 29, 29 are fixed to the lower surface of the upper plate 13 of the underground structure 10 by bolts or the like.
4 below. Therefore, it is not necessary to arrange the manhole 14 of the underground structure 10 adjacent to the inner wall 12, and the degree of freedom in designing the underground structure 10 is increased.

In the above-described embodiment, the case where the handrail member is attached to both the two pillars of the manhole ladder has been described. However, the handrail member may be attached to one of the pillars. .

[0027]

According to the present invention, a ladder body composed of two vertical columns and a plurality of horizontal rails is fixed to a bottom plate of an underground structure at a lower portion, and an upper portion of the underground structure is fixed at an upper portion. It is fixed to the inner wall or the lower surface of the upper slab, installed below the manhole of the underground structure, and a handrail member is attached to the upper end of the column so that it can move up and down so as to protrude and retract from the manhole, so that the worker can When entering and exiting from, the handrail member can be protruded from the manhole and safely raised and lowered,
In normal times when no inspection or the like is performed, the handrail member can be retracted so as not to be in the way. In addition, there is no need to place the underground manhole adjacent to the inner wall,
The degree of freedom in designing underground structures increases.

A handrail member is vertically slidably mounted on the upper end portion of the column, and the handrail member and the column are provided with engaging means for locking the handrail member in a lowered state or a raised state. Possible handrail members can be of relatively simple and robust construction.

Further, the engaging means is constituted by an engaging groove formed of a vertical portion and a horizontal portion, and an engaging protrusion slidably engaged with the engaging groove. Since the handrail member itself can be operated by moving the handrail member itself, the operation of the engagement means is facilitated.

[Brief description of the drawings]

FIG. 1 is a side elevation view of a first embodiment of the present invention, in which a handrail member of a manhole ladder is lowered.
FIG. 4B is a front elevational view (b), and a side elevational view (c) with the handrail member raised.

2 is an enlarged perspective view (a) and an exploded view (b) of a handrail member in FIG. 1;

FIG. 3 is a perspective view of a second embodiment of the present invention.

FIG. 4 is a partially enlarged sectional view of the same.

FIG. 5 is a side elevation view of the third embodiment of the present invention, in which a handrail member of a ladder for manholes is lowered.

FIG. 6 is a side elevation view of a conventional manhole ladder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Underground structure 11 Bottom plate 12 Inner wall 13 Upper plate 14 Manhole 15 Cover 20 Ladder for manhole 21 Prop 22 Opening 23 Engagement groove 23a Vertical portion 23b Horizontal portion 24 Horizontal beam 25 Lower end fixing portion 26 Handrail member 26a Slide portion 26b Projection Part 27 Engagement protrusion 28 Upper fixing member 29 Upper fixation member 30 Engagement protrusion 31 Lock hole 32 Hole 33 Spring 34 Detachable protrusion 35 Detachable cap L Lower lock position H Upper lock position

Claims (4)

[Claims] A ladder body comprising two vertical columns and a plurality of horizontal rails is installed in a manhole of an underground structure, and a handrail member is provided at an upper end portion of the column with the manhole. A ladder for manholes that can be moved up and down so that it protrudes and retracts. 2. A handrail member is slidably mounted on an upper end portion of a support up and down.
The ladder for manholes according to claim 1, further comprising an engaging means for locking the handrail member in a lowered state or a raised state. 3. An engaging means according to claim 2, wherein said engaging means comprises an engaging groove comprising a vertical portion and a horizontal portion, and an engaging projection slidably engaged with said engaging groove. Ladder for manhole. 4. The engaging means is capable of freely moving in and out of the outer periphery of the handrail member in the radial direction, and is opened through the engaging projection urged by a spring in the projecting direction and the peripheral wall of the column. 3. The ladder for manholes according to claim 2, wherein the ladder has a locking hole into which the engaging projection is fitted.