JPH09177458A - Ladder with free hanging angle - Google Patents

Abstract

(57) [Abstract] [Problem] There is no safe ladder that can be hooked in various places at different angles and that can withstand a load and keep the tread horizontal. SOLUTION: One girder composed of a plurality of parallel girder members is provided in parallel with each other, and a plurality of tread plates are installed in parallel between the parallel girders, and each tread plate has a plurality of girder material gaps at both end portions. And a ladder with a freely adjustable hooking angle, in which a fixing member at the bottom of the handrail frame is detachably attached to each girder, and a parallel of the ladders with freely hanging angles. An anti-swamming tool is provided between a plurality of beam members.The anti-swamming device is installed between a plurality of parallel beam members so that the footboard has an acute angle opposite to that of the parallel beam members. With a ladder that can be freely fixed, with a free hanging angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ladder which can be freely hooked, and more particularly to a ladder which can be freely hooked on a frame scaffold or the like.

[0002]

2. Description of the Related Art A ladder, particularly a ladder that is hung in a narrow and limited place such as a frame scaffold, usually has a single girder material, and a plurality of treads or treads are fixed to parallel girders on both sides. Was there.

A ladder having a plurality of parallel treads is hooked at an inclination angle at which the treads become horizontal due to a fixed angle between the girder and the tread, and is generally used in a place where the inclination is gentle. It was

Further, a ladder having a plurality of parallel treads and a narrow tread is used in a place where the ladder is hooked at an angle close to vertical.

[0005]

However, in the conventional ladder, a plurality of treads are fixed to the girder, and there is a problem that the treads are not horizontal unless the ladder is leaned at a fixed hanging angle. . Therefore, the hanging angle is limited by the ladder, and there is a problem that it cannot be used safely depending on the place.

In particular, when installing a ladder in a narrow and limited space such as a frame scaffold, there are various subtleties such as when it must be hung at a right angle and when a worker wants to use it safely with a gentle slope. A different angle was required. Therefore, frame scaffolds have traditionally been forced to use multiple ladders to increase safety. Further, depending on the construction site, the height and the hanging space may change depending on the time when the object to be hung on the ladder is the building base, and it is necessary to promptly deal with it.

Further, even when the ladder is hooked at an angle close to vertical, there is a problem that the worker becomes unstable when the stepped portion is a step bar, which poses a high risk.

Furthermore, when lifting a heavy object, it is necessary to more securely fix the hooking angle of the ladder.

[0009]

In order to solve the problems, one girder composed of a plurality of parallel girder members is provided in parallel with each other, and a plurality of treads are installed in parallel between the parallel girders. The ladder is rotatably bridged between a plurality of girders at both ends, and a fixing member at the bottom of the handrail frame is detachably provided on each girder. To propose.

Further, one girder composed of a plurality of parallel girder members is provided in parallel with each other, and a plurality of tread plates are rotatably installed between the two parallel girders in a parallel and rotatable manner. Each of them is rotatably bridged between a plurality of girders, and a plurality of fixing members at the bottom of the handrail frame are attached to the girders on both sides so that the girders can be detachably inserted from above the girders. We propose a ladder with fixed hanging angle, which is fixed to the beam.

Further, one girder composed of a plurality of parallel girder members provided with hook portions at the ends of the lower girder members is provided in parallel with each other,
A plurality of treads are installed in parallel between the parallel girders, and each tread is rotatably bridged between a plurality of girders at both end portions, and a fixing member at the bottom of the handrail frame for each girder. In a ladder with freely attachable and detachable hooks, anti-swarming devices are provided between parallel beam members, and the anti-swaying device is in the opposite direction of the acute angle between the step members and the parallel beam members. We propose a ladder with a free hanging angle, which can be fixed between a plurality of parallel girders at an acute angle.

[0012] Further, one girder composed of a plurality of parallel girder members provided with hooks at the ends of the lower girder members is provided in parallel with each other,
A plurality of treads are installed in parallel between the parallel girders, and each tread is rotatably bridged between a plurality of girders at both end portions, and a fixing member at the bottom of the handrail frame for each girder. In a ladder with freely attachable and detachable hooks, anti-swarming devices are provided between parallel beam members, and the anti-swaying device is in the opposite direction of the acute angle between the step members and the parallel beam members. By installing one end of the anti-smearing tool rotatably to one girder and the other end slidably attached to the other girder between a plurality of parallel girders that form an acute angle We propose a ladder with a free hanging angle that can be fixed between beam members at any angle.

Further, one girder composed of a plurality of parallel girder members provided with hooking portions at the ends of the lower girder members is provided in parallel with each other, and a plurality of treads are installed in parallel between the parallel girders, Each footboard is rotatably bridged between a plurality of girders at each of both side ends, and in each ladder, a fixing member at the lower part of the handrail frame is detachably provided, with a freely adjustable hooking angle, An anti-swamming tool is provided between a plurality of parallel beam members, and the anti-swamming device is composed of a plate-shaped body having a plurality of fixing recesses, and the plate-shaped body is rotatably attached to one beam member and the other. It is possible to fix the mounting angle freely between a plurality of parallel girders so that the foot plate has an acute angle opposite to the acute angle formed by the plurality of parallel girder materials by the fixing concave portion and the fixing bolt in the girder material. We propose a ladder with a free hanging angle.

Further, one girder composed of a plurality of parallel girder members provided with hook portions at the ends of the lower girder members is provided in parallel with each other,
A plurality of treads are installed in parallel between the parallel girders, and each tread is rotatably bridged between a plurality of girders at both end portions, and a fixing member at the bottom of the handrail frame for each girder. In a ladder with freely attachable and detachable hooks, anti-swarming devices are provided between parallel beam members, and the anti-swaying device is in the opposite direction of the acute angle between the step members and the parallel beam members. It is possible to fix the mounting angle freely between a plurality of parallel beam members so that it becomes an acute angle, and the hooking part provided at the end of the lower beam member is rotatable inside the beam member and has a concave right angle inner shape. The present invention proposes a ladder having a free hanging angle, which is a hooking portion having the ladder.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described.
First, FIG. 1 showing the side surface of the ladder according to the first embodiment.
FIG. 2 showing the front, FIG. 3 showing the plane of one footboard, FIG. 4 showing the side surface of the fixing member at the bottom of the handrail frame, FIG. 5 showing the same front, FIG. 6 showing the same plane, and section taken along line AA of FIG. Will be described with reference to FIG. 7 in a state in which the tightening screw is tightened.

The ladder is composed of a girder 1, a step board 2, a handrail frame 3, a hook portion 4 and a base portion 6.

The girder 1 is composed of a plurality of parallel girder members 5 on each side, and in this embodiment, the girder 1 on one side is composed of two parallel girder members 5. Two parallel girder members 5 are rotatable at both sides in the length direction of the mounting brackets 20 provided at the side portions of the plurality of treads 2 and at both ends in the longitudinal direction of the base portion 6 provided at the bottom of the girder. The girder 1 on one side is configured by attaching to one girder, and one girder 1 is composed of two girder materials 5.
Keep the parallel while changing the interval. The beam member 5 is a columnar body having a U-shaped cross section, and is provided with the U-shaped opening facing outward.

The two girders 1 are provided in parallel on both sides of the treads 2 with the treads 2 interposed therebetween. The plurality of treads 2 are rotatably attached to the two girders 5 at the attachment brackets 20 on both sides in the longitudinal direction thereof. In the embodiment, each girder 5 has a length of 2290 mm, the distance from the mounting position of the lowermost base portion 6 to the mounting position of the lowermost tread 2 is 300 mm, and the distance between the plurality of treads 2 is the same. Is 300 mm. The number of treads 5 is seven.

A hooking portion 4 is provided at an upper end portion of a girder member 5 below each girder 1. The hooking portion 4 is composed of a holding metal fitting and is fixed to the upper end of the girder member 5 and can be hooked on a horizontal rod or the like of the frame scaffolding.

A base portion 6 is provided at the lowermost end of each girder 1. The base portion 6 is an angle having an L-shaped cross section, and is rotatably attached to the lowermost ends of the two girder members 5 by the both side portions in the longitudinal direction of the upright portion, like the attachment bracket 2a of the footboard 2.

The footboard 2 has a length of 4 in this embodiment.
A metal plate having a width of 50 mm, a width of 240 mm, and a thickness of about 30 mm.
0 is provided. The mounting bracket 20 has a trapezoidal portion in a side view protruding upward from the thickness of the step plate, and is rotatably attached to each of the two girder members 5 at two end portions of the trapezoidal portion.

The handrail frame 3a of the first embodiment is detachably provided on each of the beams 1 on both sides. One handrail frame 3a is provided on the upper handrail part 30 and on the lower part of the handrail part 30.
Book pedestal 31 and fixing member 32 provided at the bottom of pedestal 31
Consists of

The handrail portion 30 is composed of a horizontal rod formed by bending the front and rear portions downward in a semicircular shape, and the pedestal 3 is vertically downward from the horizontal rod.
1 is provided. A second horizontal rod is fixedly provided at an intermediate portion of the two pedestals 31.

Fixing member 3 connected and fixed to the lower part of the pedestal 31
Reference numeral 2 denotes an outer member 32a formed by arranging two hollow prismatic bodies in parallel and connected by a plate-like portion, and an inner member 32b similarly formed by arranging two hollow prismatic bodies in parallel and connected by a plate-like portion. , And a connecting portion 32c for connecting the two parts at the upper part, and a fixing bolt 32d for tightening the outer member 32a and the inner member 32b.

The fixing member 32 has a space 32 between the outer member 32a and the inner member 32b, which is wider than the width of the beam member 1 by about 1 mm.
g and are juxtaposed. In this embodiment, the width of the beam member 5 is 2
5 mm, gap 32 between outer member 32a and inner member 32b
The width of g is 26 mm. Outer member 32a and inner member 3
2b is connected and fixed by a connecting portion 32c which is a U-shaped member having a U-shaped cross section which opens downward. Outer member 3
The plate-shaped member 2a is provided with vertically spaced through holes 32e, and the plate-shaped member of the inner member 32b at positions corresponding to the respective through holes 32e is provided with two tightening holes 32f internally threaded. .

When the ladder is hooked and the hooking angle is determined, the fixing member 32 sandwiches the upper and lower girder members 5 in the gap 32g from above in the upper part of the girder 1 so that the connecting portion 32c is the upper girder member 5. Straddle it and push it in until it stops. Further, fix the two fixing bolts 32d, which are butterfly bolts, to the outer part 3 respectively.
The upper and lower through holes 32e of 2a are passed through, passing through the gap 32g, and screwed into the upper and lower tightening holes 32f of the inner portion 32b. One fixing bolt 32d is located between the upper and lower beam members 5, and the other fixing bolt 32d is located below the lower beam member 5.

In the handrail frame 3a, when the hooking angle of the ladder is determined, the fixing members 32 are fixed to the upper portions of the girders 1 on both sides by the fixing bolts 3.
Fix by tightening 2d.

Since the two girder members 5 on each side, the plurality of treads 2 and the base portion 6 are rotatable, the ladder can be hooked at any angle while keeping the plurality of treads 2 horizontal. Then, in order to lock the ladder at the desired angle on the spot such as a frame scaffold and fix the locking angle, the handrail frame 3
This is done by fixing a to the girders 1 on both sides. Since the fixing member 32 of the handrail frame 3a is attached to the two girder members 5 and the gap between the two girder members 5 is fixed by tightening the fixing bolt 32d, the angle between the girder 1 and the step board 2 is fixed.

Next, FIG. 8 is a side view of a ladder which is a second embodiment of the present invention, FIG. 9 is a front view of the same, FIG. 10 is a side view of a handrail frame, and FIG.
1. Similarly, FIG. 12, the third showing the enlarged side surface of the anti-smudge tool.
FIG. 13 is a partial side view of a ladder which is an embodiment, FIG. 14 is a partial side view of a ladder which is a fourth embodiment, and FIG. 15 is a perspective view of a latching portion of a ladder which is a fifth embodiment. It will be explained based on.

The ladder according to the second embodiment of the present invention is
It is composed of a girder 1, a footboard 2, a handrail frame 3b, a hooking portion 4, a base portion 6 and an anti-slip member 7.

The girder 1 is composed of a plurality of parallel girder members 5 on each side, and in this embodiment, the girder 1 on one side is composed of two parallel girder members 5a and 5b. The two parallel girder members 5a and 5b are rotated at both sides in the longitudinal direction of the mounting bracket 20 provided at the side portions of the plurality of treads 2 and at both end portions in the longitudinal direction of the base portion 6 provided at the bottom of the girder. The girder 1 on one side is configured by being movably attached, and one girder 1 keeps parallel while changing the interval between the two girder members 5. The beam member 5 is a columnar body having a U-shaped cross section, and is provided with the U-shaped opening facing outward.

In the ladder of the third embodiment, since the length of the girder member 5 is relatively long (the length is 3790 mm), two girder members 5 are used.
The width of the lower girder member 5b is wider than that of the upper girder member 5a.

The two girders 1 are provided in parallel on both sides of the treads 2 with the treads 2 interposed therebetween. The plurality of treads 2 are rotatably attached to the two girders 5 at the attachment brackets 20 on both sides in the longitudinal direction thereof. In this embodiment, each girder member 5 has a length of 2290 mm, and from the mounting position of the lowermost base portion 6 to the lowermost tread 2
The distance to the mounting position is 300 mm, and the distance between the plurality of treads 2 is also 300 mm. In this embodiment, the number of treads 2 is 7, but if not shown, the number of treads 2 is 4 when the length of the girder 5 is 1390 mm.
When the length of the sheet or girder material 5 is 3790 mm, the number of treads 2 is 12 sheets. Depending on the length of the girder 5, it is also 2
The number of treads 2 from about 1 to 15 is possible.

A hooking portion 4a is provided at the upper end of the girder member 5 below each girder 1. The hooking portion 4a is formed by fixing a gripping metal member to the girder material 5, and can be hooked on a horizontal rod or the like of a frame scaffold.

The latching portion 4b of the ladder shown in FIG. 15, which is the fifth embodiment, is used when the member to be latched is a square bar having right-angled corners. It is a plate-like body bent at a right angle having a concave right-angled inner shape corresponding to the convex right-angled surface of a certain square bar. The hooking portion 4b is provided on a plate-like body fixed to the upper end of the girder member 5 so as to be vertically rotatable, and is angle-fixed by an angle fixing bolt 40b. After the hooking portion 4b is hooked, it is detachably fixed to the hooked member A by the fixing bolt 41b.

A base portion 6 is provided at the lowermost end of each girder 1. The base portion 6 is an angle having an L-shaped cross section, and is rotatably attached to the lowermost ends of the two girder members 5 by the both side portions in the longitudinal direction of the upright portion, like the attachment bracket 20 of the footboard 2.

The footboard 2 has a length of 4 in this embodiment.
A metal plate having a width of 50 mm, a width of 240 mm, and a thickness of 30 mm. The mounting bracket 2 is provided on both sides in the length direction.
0 is provided. The mounting bracket 20 has a trapezoidal portion in a side view protruding upward from the thickness of the step plate, and is rotatably attached to each of the two girder members 5 at two end portions of the trapezoidal portion.

One handrail frame 3b is detachably provided on each of the girders 1 on both sides, but if the girder member 5 is long, two or two or more handrail frames 3b are provided. Further, when the length of the beam member 5 is short, a shorter handrail frame (not shown) is provided. One handrail frame 3b includes an upper handrail portion 30, two pillars 31 provided at the lower portion of the handrail portion 30, and a fixing member 33 provided at the lower portion of the pillar 31.

The handrail portion 30 is composed of a horizontal rod formed by bending the front and rear portions downward in a semicircular shape, and the pedestal 3 is vertically downward from the horizontal rod.
1 is provided. A second horizontal rod is fixedly provided at an intermediate portion of the two pedestals 31. The length of the beam 5 is short 1390m
In the case of a handrail frame (not shown) provided on a ladder with four footboards and four footboards, the front and rear semicircular portions of the handrail portion 30 are only one side, and the other side is a right angle with a horizontal rod. Bend it into a pedestal 31 as it is.

Fixing member 3 connected and fixed to the lower part of the pedestal 31
3 is fixed to the pedestal 31 via a connecting member 33b having two plate-shaped bodies 33a arranged side by side in the width direction of the ladder and having a U-shaped cross section. The plate-like body 33a is provided so that the interval between the two is substantially the same as the width of the beam member 5 and the fixing groove 33c is opened to the side surface side of the plate-like body. Two fixing grooves 33c are provided in the length direction,
The larger the angle at which the ladder is hooked with the horizon, the larger the spacing between the parallel beam members 5, but the width intervals corresponding to the width between the beam members 5 are provided.

A fixing bolt nut 33d is provided in the fixing groove 33c from the opening side. In this embodiment, the fixing bolt nut 33d is composed of a press butterfly bolt and a nut, and by tightening the bolt, the interval between the parallel plate-shaped bodies 33a is narrowed and the girder member 5 is sandwiched and fixed.

The anti-smudge 7 is composed of two parallel beam members 5
The bridges 1a and 5b are provided so as to be provided outside the left and right girders 1, respectively, but it is also possible to provide only on the girder 1 on one side. When the ladder of the present invention is hung, the acute angle and the obtuse angle are formed with respect to the ground plane B except when the ladder is hooked vertically and the angle with the ground plane B differs and the ladder is hooked vertically. The respective angles formed by the girder material 5 of this ladder and the ground plane B are the respective angles of the girder material 5 and the tread plate 2. The anti-sweep tool 7 is attached so as to form an acute angle opposite to the acute angle formed by the girder material 5 and the footboard 2. That is, the anti-smudge 7 is provided between the girders 5 parallel to the direction crossing the direction of the step board 2, and the mounting angle is changed depending on the hooking angle of the ladder. The direction of the acute angle formed by the girder material 5 and the footboard 2 is opposite.

In the second embodiment, the anti-slip 7a
Includes a tie plate 70, a slide plate 71, a bolt 72 that can rotatably connect and fix the two plates 70, 71, and an eye nut 73 that is screwed into the bolt 72. The tie plate 70 has a hole 74 formed at the end opposite to the side where the slide plate 71 is connected, and a fixing pin 75 is fitted into the hole 74 so as to be rotatably attached to an appropriate position of the upper beam member 5a. . Slide plate 71
Is slidably attached to the lower girder 5b. Two stop bolts 76 are projected at a position where the slide plate 71 of the lower girder 5b is slidably attached to a position lower than the pivotal attachment position of the tie plate 70 when the ladder is hooked. It is provided so as to be slidable within the interval range. After adjusting the hooking angle of the ladder, the anti-sweep tool 7a is rotated by tightening the eye nut 73 on the bolt 72 to tighten the tie plate 70 and the slide plate 71.
Are fixed to each other at a tightening angle, and the slide plate 71 is fixed to the girder 5b.

In the anti-swamming tool 7b of the third embodiment, when the length of the girder member 5 of the ladder is long, the width of the lower girder member 50b becomes wider. A slide plate guide 77 having a narrow width is provided, and the slide plate 71 is slidably mounted in the slide plate guide 77. Stop bolts 76 are provided at both ends of the slide plate guide 77. Slide plate 71, tie plate 70, bolt 72, eye nut 73
Is the same as in the second embodiment.

As another example of the anti-smearing tools 7a, 7b of the second and third embodiments, the anti-smearing tools 7a, 7b are shown.
It is also possible to provide the girders 5a and 5b with the top and bottom of b reversed. That is, the lower end of the tie plate 70 is rotatably attached to the lower beam member 5b, and the slide plate 71 is
Is slidably attached to the upper beam member 5a.

A fourth embodiment of the anti-smudge device 7c shown in FIG. 14 is a rectangular plate-like member, and is provided with a plurality of fixing recesses 70c in the lengthwise direction which are open on both upper sides.
The lower end is rotatably attached to the lower beam member 5b by a rotating pin 74c. The anti-swoom tool 7c of the fourth embodiment has a fixing recess 70c corresponding to an appropriate position depending on the hooking angle of the ladder, and a fixing hole 72c of the fixing plate 71c fixed to the upper beam 5a. To be fixed by tightening the fixing bolt 73c.

As another example of the anti-boom member 7c of the fourth embodiment, the fixing plate member 71c is turned upside down so that the upper end portion is rotatably attached to the upper beam member 5a, and a plurality of them are provided. It is also possible to detachably fix the fixing recess 70c to the lower beam member 5b.

Since the two girder members 5 on each side, the plurality of treads 2 and the base portion 6 are rotatable, the ladder can be hooked at any angle while keeping the plurality of treads 2 horizontal. Then, in order to lock the ladder at a desired angle at a site such as a frame scaffold, and fix the locking angle, the handrail frame 3b is fixed to the girders 1 on both sides, and the sliding portions of the anti-smudge tools 7a and 7b are fixed. The side is fixed to the lower beam members 5b and 50b, and the anti-smudge 7c is performed by fixing the fixing recess 70c to the upper beam member 5a.

[0049]

Therefore, according to the present invention, the footboard can be kept horizontal regardless of the hanging angle of the ladder, and the worker can work safely and reliably. Therefore, it is possible to immediately cope with the site where the height is different.

In particular, when a ladder is installed at a construction site such as a frame scaffold, the ladder can be hung with a single ladder according to the size of the space that requires it, and angles up to nearly right angles and gentle inclination angles can be achieved. Since it can be hooked at any angle, work efficiency on site is greatly improved. In addition, since one type of ladder can be used at various sites, it is easy to carry and store.

[Brief description of the drawings]

FIG. 1 is a side view of a ladder showing a first embodiment of the present invention.

FIG. 2 is also a front view

FIG. 3 is a plan view of one tread plate.

FIG. 4 is a side view of a fixing member below the handrail frame.

FIG. 5 is also a front view

FIG. 6 is a plan view of the same.

7 is a cross-sectional explanatory view showing a cross-section taken along the line AA of FIG. 5 with a fixing bolt tightened.

FIG. 8 is a side view of the ladder showing the second embodiment of the present invention.

[Figure 9] Similarly, a front view

FIG. 10 is a side view of the handrail frame of FIG.

FIG. 11 is a plan view of the same anti-smudge device.

FIG. 12 is a side view of the anti-swoom tool as well.

FIG. 13 is a partial side view of a ladder showing the third embodiment of the present invention.

FIG. 14 is a partial side view of a ladder showing the fourth embodiment of the present invention.

FIG. 15 is a perspective view of a hooking portion of a ladder showing a fifth embodiment of the present invention.

[Explanation of symbols]

 1 Girder 2 Footboard 20 Mounting Bracket (of Footboard) 3a Handrail Frame (First Embodiment) 30 Handrail Part 31 Leg Pillar 32 Fixing Member 32a Outer Member 32b Inner Member 32c Connecting Part 32d Fixing Bolt 32e Through Hole 32f Tightening Hole 32g Air gap 3b Handrail frame (2nd, 3rd, 4th, 5th embodiment) 33 Fixing member 33a Plate-like body 33b Connecting member 33c Fixing groove 33d Fixing bolt nut 4a Hooking part 4b Hooking part 40b Angle fixing Bolt 41b Fixing bolt 5 Girder material 5a Upper girder material 5b Lower girder material 50b Wide lower girder material 6 Base portion 7 Anti-smoke tool 7a Anti-smoke tool 70 Type plate 71 Slide plate 72 Bolt 73 Eye nut 74 hole 75 Fixing pin 76 Stop bolt 7b Anti-smoke tool 77 Slide plate guide 7c Anti-smoke Ingredients 70c fixing recesses 71c securing the plate member 72c fixed holes 73c fixing bolt 74c pivot pin

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Nagayoshi Yamaguchi 1-10-12 Nihonbashi Horidomecho, Chuo-ku, Tokyo Chuo Built Industry Co., Ltd.

Claims (6)

[Claims] 1. A single girder composed of a plurality of parallel girder members is provided in parallel with each other, and a plurality of tread plates are installed in parallel between the parallel girders, and each tread plate has a plurality of girder members at both end portions thereof. A ladder with a freely adjustable hanging angle, which is rotatably bridged in between and a fixing member at the bottom of the handrail frame is detachably attached to each girder. 2. One girder made of a plurality of parallel girder members is provided in parallel with each other, and a plurality of tread plates are rotatably and rotatably installed between the two parallel girders. Each of them is rotatably bridged between a plurality of girders, and a plurality of fixing members at the bottom of the handrail frame are attached to the girders on both sides so that the girders can be detachably inserted from above the girders. A ladder with a free hanging angle, which is fixed to the girder material. 3. One girder composed of a plurality of parallel girders provided with hooks at the ends of the lower girders is provided in parallel with each other, and a plurality of treads are installed in parallel between the parallel girders, Each footboard is rotatably bridged between a plurality of girders at each of both side ends, and in each ladder, a fixing member at the lower part of the handrail frame is detachably provided, with a freely adjustable hooking angle, An anti-swamming tool is provided between a plurality of parallel girder materials, and the anti-swamming tool is provided between a plurality of parallel girder materials such that the footboard has an acute angle opposite to that of the parallel girder material. A ladder with a freely adjustable hook angle that can be fixed at any angle. 4. One girder composed of a plurality of parallel girder members provided with hooking portions at the ends of the lower girder members is provided in parallel to each other, and a plurality of treads are installed in parallel between the parallel girders. Each footboard is rotatably bridged between a plurality of girders at each of both side ends, and in each ladder, a fixing member at the lower part of the handrail frame is detachably provided, with a freely adjustable hooking angle, An anti-swamming tool is provided between a plurality of parallel girder materials, and the anti-swamming tool is provided between a plurality of parallel girder materials such that the footboard has an acute angle opposite to that of the parallel girder material. , Characterized in that one end of the anti-smearing tool is rotatably attached to one girder material and the other end is slidably attached to the other girder material so that the mounting angle can be freely fixed between the girder materials. A ladder with a free hanging angle. 5. One girder composed of a plurality of parallel girders provided with hooking portions at the ends of the lower girders is provided in parallel with each other, and a plurality of treads are installed in parallel between the parallel girders, Each footboard is rotatably bridged between a plurality of girders at each of both side ends, and in each ladder, a fixing member at the lower part of the handrail frame is detachably provided, with a freely adjustable hooking angle, An anti-swamming tool is provided between a plurality of parallel beam members, and the anti-swamming device is composed of a plate-shaped body having a plurality of fixing recesses, and the plate-shaped body is rotatably attached to one beam member and the other. It is possible to fix the mounting angle freely between a plurality of parallel girders so that the foot plate has an acute angle opposite to the acute angle formed by the plurality of parallel girder materials by the fixing concave portion and the fixing bolt in the girder material. A ladder with a flexible hanging angle. 6. One girder composed of a plurality of parallel girder members provided with hooks at the ends of the lower girder members is provided in parallel with each other, and a plurality of treads are installed in parallel between the parallel girders. Each footboard is rotatably bridged between a plurality of girders at each of both side ends, and in each ladder, a fixing member at the lower part of the handrail frame is detachably provided, with a freely adjustable hooking angle, An anti-swamming tool is provided between a plurality of parallel girder materials, and the anti-swamming tool is provided between a plurality of parallel girder materials such that the footboard has an acute angle opposite to that of the parallel girder material. Mounting angle that can be fixed freely, and that the latching part provided at the end of the lower beam is a latching part that is rotatable on the beam and has a concave right angle inner shape. Free ladder.