JPH11350511A - Manhole ladder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely and easily access a manhole. SOLUTION: A manhole ladder so constituted that an upper hook f1 and a lower hook f2 are locked respectively to an upper landing step T1 and a lower landing step T2 inside a manhole from the upper side and lower side and that the upper half thereof is projected upward from a manhole to mount. Then, at least one of both upper and lower hooks f1 and f2 is mounted to a pair of right and left cylindrical posts P1 and P2 of the ladder in a coaxially rotable manner, and it is mounted to a rotationally driven male screw bar 6 by rotational operation of a handle in the upper part of the ladder through a power transfer device in a vertically movable manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manhole ladder.

[0002]

2. Description of the Related Art A conventional manhole laid on a road or the like generally has a ramp for raising and lowering inside, and there is no ramp or a substitute for the ramp near the road surface. For this reason, when entering and exiting using the internal ramp, there was no place to catch at the beginning or end, which was dangerous.

[0003] That is, near the road surface, the only place that can be grasped is the edge of the manhole or the road surface, and there is no substitute for a railing or ramp, so the posture of the first step when entering the manhole and the posture of the last step when exiting the manhole are unstable. It was dangerous because it could become corrupt.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a ladder for manholes which makes entering and exiting the manhole safe and easy. I do.

[0005]

A ladder for a manhole provided by the present invention is provided with an upper hook and a lower hook on an upper ramp and a lower ramp in the manhole, respectively, from above and below, or from below and above. A ladder to be hung and mounted with the upper half protruding upward from the manhole, wherein at least one of the upper hook and the lower hook is coaxially rotatably attached to a cylindrical support of the ladder, The ladder is vertically movably attached to a male screw rod which is rotationally driven through a power transmission means by a rotation operation of a handle on an upper part of the ladder.

[0006]

The ladder for manhole of the present invention can be mounted on the manhole by hooking the upper hook and the lower hook on the ramp in the manhole.

In the mounted state, the upper half of the ladder projects upward from the manhole or stands upright.

[0008]

Embodiments of the present invention will be described below with reference to embodiments.

(Embodiment 1) FIG. 1 is a front view showing a state in which a ladder for manhole of Embodiment 1 is mounted on a manhole, and FIG.
Is a side view of the ladder, and FIG. 3 is a view schematically showing an operation structure of the ladder of FIG.

In the figure, H ₁ is a ladder main body, which has a structure in which a horizontal pipe Y is integrally formed on a pair of right and left columns P ₁ and P ₂ . The horizontal pipe Y is attached to pipes 1 to 4 described later. The pair of left and right supports P ₁ and P ₂ are configured by connecting left and right upper pipes 1 and 2 and left and right lower pipes 3 and 4 with left and right male screw rods 5 and 6, respectively.

A pair of left and right downward first hooks f ₁ are attached to the lower horizontal pipes Y of the upper pipes 1 and 2, and a pair of left and right upward second hooks are attached to the horizontal pipes Y of the lower pipes 3 and 4. hook f ₂ is attached.

As shown in FIG. 3, the externally threaded rods 5, 6 are mounted on upper pipes 1, 2 by bearings 7, 8, and are rotatable coaxially with the pipes 1, 2.
The lower ends of the male threaded rods 5 and 6 are screwed into female threads provided in the lower pipes 3 and 4.

Reference numerals 9 and 10 denote first power transmission shafts disposed in the upper pipes 1 and 2 and having lower ends connected to the externally threaded rods 5 and 6, respectively, and are coaxially rotatable with the threaded rods 5 and 6. Has become.

Reference numeral 11 denotes a second power transmission shaft which is rotated by a rotating operation of the handle 12, and the rotation of the second power transmission shaft is made via a pair of right and left helical gears 13 and 14 to the first power transmission shafts 9 and 10.
Is transmitted to Reference numerals 15 and 16 denote the above-mentioned gears 1
3 and 14 are gab boxes in which are stored.

Since the ladder of the first embodiment has the above-described structure, when the handle 12 is turned counterclockwise, the lower pipes 3 and 4 are lowered, and the distance between the first hook f ₁ and the second hook f ₂ is increased. Opens. When opened, the first hook f ₁ is hooked from above on the upper ramp T ₁ of the manhole M, the handle 12 is turned to the right, the lower pipes 3 and 4 are raised, and the second hook f ₂ is lowered to the lower ramp of the manhole M. hooked from the lower to T _2.

In this manner, the ladder is mounted in an upright state on the ramps T ₁ and T ₂ of the manhole M, and the upper half protrudes from the opening of the manhole M. Workers can come in and out while holding on to this ladder, and there is no danger of corruption when going in and out.

Further, since the second hook f ₂ is structured to move up and down by a power transmission mechanism using gears, the second hook f ₂ does not loosen due to the movement of the second hook f ₂ and is safe.

(Embodiment 2) FIG. 4 shows a ladder for a manhole according to a second embodiment. This is a modified example of the first embodiment, which is a ladder which can be used for a manhole having a concave opening side.

In this type of manhole M, the positions of the upper wrap 21 and the lower wrap 22 are inclined inward.
When the ladder of the first embodiment is attached to the ramps 21 and 22 having such a positional relationship, the upper opening of the manhole M is obstructed by the ladder and the entrance is narrowed.

The ladder of the second embodiment is such that the upper pipes 1 and 2 of the first embodiment are bent in a U-shape so that the upper half of the ladder stands upright to facilitate access to the manhole M. It is.

In this case, the bent portions of the pipes 1 and 2 of the first power transmission shafts 9 and 10 are constant velocity universal joints, not shown.

(Embodiment 3) FIG. 5 shows a ladder for a manhole according to a third embodiment. In this ladder, the upper pipes 1 and 2 of the ladder of the first embodiment are bent in an S-shape toward the hooks f ₁ and f ₂ so as to easily enter and exit the manhole M. Also in this case, the first power transmission shaft 9,
Reference numeral 10 denotes a constant velocity universal joint in which the bent portions of the pipes 1 and 2 are not shown.

(Embodiment 4) FIG. 6 is a perspective view of a ladder for manholes of Embodiment 4, and FIG. 7 is a diagram schematically showing an operation structure of the ladder of FIG.

In the figure, H ₂ is a ladder main body, and has a structure in which a pair of left and right columns P ₃ and P ₄ is integrally formed with a horizontal pipe Y ₁ . Horizontal Pipe Y ₁ is a pipe 4 to be described later
1 to 46.

The pair of right and left columns P ₃ and P ₄ connect the left and right upper pipes 41 and 42 and the left and right lower pipes 43 and 44 with left and right male screw rods 45 and 46, respectively. Are formed by screwing a pair of left and right intermediate pipes 47 and 48 into female screw portions. A pair of left and right lower pipes 43, 44 a pair of left and right intermediate pipe 47, 48 are integrally connected by a transverse pipe Y _1, respectively.

A first upward hook f ₁ is attached to the lower pipes 43 and 44, and a second downward hook f ₂ is attached to the intermediate pipes 47 and 48.

As shown in FIG. 7, the male screw rods 45, 46 are mounted on upper pipes 41, 42 by bearings 49, 50, and are rotatable coaxially with the pipes 41, 42. The lower ends of the female screw rods 45 and 46 are attached to the lower pipes 43 and 44 by bearings 51 and 52 so as to be axially rotatable.

Numerals 53 and 54 are first power transmission shafts which are disposed in the upper pipes 41 and 42 and whose lower ends are connected to the external threaded rods 45 and 46, and are coaxially rotatable with the threaded rods 45 and 46. Has become.

Reference numeral 55 denotes a second power transmission shaft which rotates by operating a handle 56. The rotation of the second power transmission shaft is made via a pair of right and left helical gears 57, 58.
4 is transmitted. 59 and 60 are gear boxes in which the above-mentioned bevel gears 57 and 58 are stored.

Since the ladder of the fourth embodiment has the above-described configuration, when the handle 56 is turned to the left, the female screw rod 4
5,46 is rotated counterclockwise, the second is increased hooks f _2, the first interval of the hook f ₁ and the second hook f ₂ is opened. When opened, hook the first hook f ₂ on the upper ramp from above,
Turning the handle 56 to the right, the second hook f ₂ decreases (relatively, the first hook f ₁ is increased), is hooked from below on the lower ramp.

In this manner, the ladder is mounted upright on the ramp of the manhole, and the upper half protrudes from the manhole. An operator can enter and exit while holding on to this ladder.

The male screw rods 45, 4 in the fourth embodiment
Instead of 6, the upper half portion is the right male thread, those lower half portion by using the male screw rod has a left male screw, corresponds to the second intermediate pipe 47, 48 provided with a hook f _2, two pairs prepared However, it is also possible to adopt a configuration in which one is screwed into the right-hand thread portion of the male screw bar and the other is screwed into the left-hand thread portion of the male screw bar. In this way, the hooks simultaneously move in opposite directions.

Further, the ladder of the fourth embodiment has the first hook f
₁ and the second hook f _2, as shown in FIG. 8, prepared as removable attachment _{a 1, a 2, a 3} , a 4,
It is also possible to adopt a configuration capable of coping with a ramp attached by providing steps alternately. At this time, attachment a ₁
And a ₂ and the attachment a ₃ and a ₄ is to be mounted in such a screw is shifted vertically by a step portion of ramp.

(Embodiment 5) FIG. 9 is a perspective view of a ladder for manholes according to a fifth embodiment. The fifth embodiment, the post P _3, P ₄ in Example 4, and only the post P _4, an example in which a horizontal pipe Y ₂ on the left and right sides. The operation and effect are not essentially different from those of the fourth embodiment.

[0035]

As described above, according to the ladder for manholes of the present invention, since it has the above-described structure,
Getting in and out of manholes is safe and easy.

[Brief description of the drawings]

FIG. 1 is a front view of a manhole ladder according to a first embodiment.

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a view showing an operation structure of the ladder of FIG. 1;

FIG. 4 is a side view of a ladder for manholes according to the second embodiment.

FIG. 5 is a side view of a ladder for manholes according to the third embodiment.

FIG. 6 is a side view of a ladder for manholes according to a fourth embodiment.

FIG. 7 is a view showing an operation structure of the ladder of FIG. 6;

FIG. 8 is a perspective view showing a modification of the fourth embodiment.

FIG. 9 is a perspective view of a ladder for manholes according to a fifth embodiment.

[Explanation of symbols]

M manhole H _1, H ₂ ladder body _{P 1, P 2, P 3} , P 4 post Y, Y _1, Y ₂ horizontal pipe 1,2,41,42 upper pipe 3,4,43,44 lower Paibu 5, 6,45,46 male screw rod f ₁ first hook f ₂ second hook 7,8,51,52 bearing 9,10,53,54 first power transmission shaft 11, 15 second power transmission shaft 13,14,57 , 28 thumping bevel gears T ₁ upper ramp T ₂ lower ramp 47 intermediate pipe

Claims (1)

[Claims] 1. An upper hook and a lower hook are respectively hooked from an upper side and a lower side or from a lower side and an upper side, respectively, on an upper ramp and a lower ramp in a manhole, and the upper half projects upward from the manhole. A ladder to be mounted and mounted, wherein at least one of the upper hook and the lower hook is coaxially rotatably attached to a cylindrical support of the ladder, and is rotated via a power transmission means by a rotation operation of a handle on the ladder upper part. A ladder for manholes, characterized in that it is attached to a male screw rod that is driven to rotate and that can be moved up and down.