JP2592557Y2 - Mobile ladder - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable ladder removably attached to, for example, a step bar protruding from an inner wall of a manhole.

[0002]

2. Description of the Related Art For example, as shown in FIG. 10, when stepping into and out of a manhole 4 along a step bar 2 and a manhole ladder 3 projecting from an inner wall surface 1a of a manhole entrance 1, the step bar 2 is slippery. In addition, since the bar interval α is wide, there is no support for the body, and it is necessary to climb up and down in an unstable posture, there is a danger of falling, which is very dangerous.

Therefore, a ladder is conventionally attached to the step bar 2 with a construction metal fitting, a wire or the like.

[0004]

[Problems to be Solved by the Invention] In the above conventional configuration,
The installation and removal of the ladder was troublesome, and the ladder sometimes came off the step bar unexpectedly.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a portable ladder that can be easily and securely attached to a step bar and can be easily removed from the step bar.

[0006]

According to one aspect of the present invention, there is provided a portable ladder attached to a plurality of step bars protruding from a wall at predetermined intervals in a vertical direction. A ladder main body composed of a pair of left and right stringers and a plurality of treads arranged at predetermined intervals in the vertical direction between the two stringers, and attached to the lower part of each stringer at a predetermined interval in the vertical direction, A downward fitting concave portion formed at the tip portion is pivotally supported by four step bar fitting frames, upper, lower, left and right, which are respectively fitted to the two step bars, and both lower step bar fitting frames. A hook for closing the fitting recess which is urged by the connector to close the entrance of the fitting recess, and is provided at an upper portion of the ladder main body, and the two hooks are opposed to a spring via a cord in a fitting recess opening direction. With an operating lever for rotating It is characterized in Rukoto.

According to a second aspect of the present invention, of the four upper, lower, left and right step bar fitting frames attached to the lower portions of the two vertical beams, the lower two step bar fitting frames are fixed to the vertical beams. In addition, the upper step bar fitting frames can be moved along the vertical girder, and the upper step bar fitting frames are integrally connected to each other by a tread bar.

[0008] The invention according to claim 3 is characterized in that the upper part from the central part of the two vertical beams is bent in a substantially rectangular shape toward the tip end side of the step bar fitting frame.

According to a fourth aspect of the present invention, the cord body is divided into an upper cord body part and a lower cord body part, and a cord body moving length extension mechanism is interposed between the upper and lower cord bodies. The cable body moving length expanding mechanism has a rotating rod pivotally supported by a vertical rail,
The lower end of the upper rope portion is connected to the base end of the turning rod, and the upper end of the lower rope portion is connected to the tip of the turning rod.

[0010]

According to the first aspect of the present invention, when the portable ladder is attached to the step bar, the operation lever is operated to rotate the hook for closing the fitting recess in the opening direction of the fitting recess, and the up and down movement is performed. It is only necessary to release the operation of the operation lever after fitting the fitting recesses of the four left and right step bar fitting frames to the upper and lower two step bars, respectively. Thereby, since the entrance of the fitting recess fitted to the lower step bar is closed by the fitting recess closing hook, the portable ladder can be securely attached to the step bar so as not to accidentally come off. You can safely climb up and down along the portable ladder. Also, when removing the portable ladder from the step bar, simply operate the operation lever to rotate the fitting recess closing hook in the fitting recess opening direction, and then simply pull up the portable ladder, thereby easily. Can be removed.

According to the present invention, of the four step bar fitting frames, the upper and lower step bar fitting frames are movable along the vertical girder. Since the interval between the step bar fitting frames can be adjusted so as to be freely scalable, the portable ladder can be attached to various step bars having different bar intervals in accordance with the bar interval.

According to the third aspect of the present invention, since the upper portions of the two longitudinal beams from the central portion are bent in a substantially rectangular shape toward the distal end portion of the step bar fitting frame, they travel along the portable ladder. When climbing up and down, the upper part of the ladder main body does not get in the way and can easily climb up and down.

According to the present invention, the cord is divided into an upper cord portion and a lower cord portion, and a cord moving length extension mechanism is interposed between the upper and lower cord portions. Since the operation of the operation lever can be enlarged and the hook for opening and closing the fitting recess can be largely rotated, the opening and closing of the fitting recess can be easily performed only by operating the operation lever small.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 9 shows a portable ladder attached to a step bar 2 protruding from the inner wall surface 1a of the manhole doorway 1. As shown in FIGS.
a, 6a and a plurality of tread bars 6b arranged at predetermined intervals in the vertical direction between the two vertical beams 6a, 6a.
And four step bar fitting frames 8a which are attached to the lower portions of the vertical beams 6a, 6a at predetermined intervals in the vertical direction and are fitted to the two step bars 2, 2, respectively.
To 8d.

As shown in FIG. 1, both columns 6a, 6a
The upper part of the ladder body 6 is bent at a predetermined angle γ in a substantially rectangular shape from the center part to the tip end side of the step bar fitting frames 8a to 8d so that the upper part of the ladder main body 6 is obstructed when climbing up and down along the portable ladder. And can easily climb up and down.

Each of the step bar fitting frames 8a to 8d is shown in FIG.
As shown in FIG. 6, the frame body 9 has a U-shape in plan view, and a pair of upper and lower connecting fittings 10 and 11 for integrally connecting both end portions 9a of the frame body 9 to each other. Parts 9a, 9
a, a concave portion 12 is formed downwardly to be fitted into the upper and lower two step bars 2, 2, and the frame bodies 9, 9 of the left and right step bar fitting frames 8 a, 8 b and 8 c, 8 d are connected to the tread bar 6 b. Are integrally connected by

Also, the lower step bar fitting frames 8a,
In FIG. 8b, as shown in FIGS. 3 and 4, the base end of the frame body 9 is fastened to the longitudinal beams 6a, 6a by bolts and nuts 13. In the upper step bar fitting frames 8c, 8d,
As shown in FIGS. 5 and 6, a rectangular fitting hole 16 is formed at the base end of the U-shaped frame 15 fixed to the distal end portion 9 a of the frame main body 9. By being fitted to the beams 6a, 6a, the upper step bar fitting frames 8c, 8d are movable along the vertical beams 6a, 6a. ,
Since the interval β between 8b and 8c, 8d can be adjusted so as to be able to expand and contract freely, a portable ladder can be attached to various step bars 2 and 2 having different bar intervals α in accordance with the bar interval α. .

5 and 6, reference numeral 17 denotes a fitting frame locking device provided on one of the upper step bar fitting frames 8c and 8d, which is fixed to the base end side wall of the frame body 9. Nut 17
a, a bolt 17c with an operation knob 17b screwed to the nut 17a, and a locking piece 17d inserted into the recess of the nut 17a.
The step bar fitting frames 8c and 8d can be locked at predetermined heights of the vertical beams 6a and 6a by making the 7d contact the side surfaces of the vertical beams 6a.

As shown in FIGS. 3 and 4, the lower step bar fitting frames 8a and 8b have a pivot shaft 18 attached to the frame body 9.
A hook 20 for closing a fitting concave portion, which is substantially U-shaped in a side view and is closed by a spring 19 and closed by a spring 19, is provided as shown in a virtual line in FIG. And an operation lever 21 pivotally attached to the upper end of one of the stringers 6a.
By rotating the hook 20, the hook 20 can be turned in the opening direction of the fitting recess against the spring 19 via the cord 22 (see the phantom line in FIG. 3).

As shown in FIG. 2, the cord 22 is divided into an upper cord portion 22a and lower cord portions 22b and 22c, and a cord is provided between the upper and lower cord portions 22a and 22b and 22c. A body moving length expanding mechanism 23 is interposed, and as shown in FIGS. 7 and 8, the cord moving length expanding mechanism 23 is a rotary shaft rotatably inserted into the hollow portion of the tread bar 6b. 2
4 and a pair of rotating rods 2 protruding from both ends of the rotating shaft 24.
5 and 25, and the lower end of the upper cable body portion 22a is connected to the base end of one of the rotating rods 25.
The upper end portions of the lower cord portions 22b and 22c are connected to the distal end portion of the rotating rod 25 from the connection position of the upper cord portion 22a to the axis of the rotating shaft 24 as shown in FIG. Since the distance R from the connecting position of the lower rope portions 22b and 22c to the axis of the rotary shaft 24 is larger than the distance r, the turning operation of the operation lever 21 is enlarged to open and close the fitting recess. The hook 20 can be largely rotated.

In the above configuration, when the portable ladder is mounted on the step bars 2, 2, the interval β between the upper and lower step bar fitting frames 8 a, 8 b and 8 c, 8 d is set to the bar interval of the step bars 2, 2. While slightly larger than α,
Hook 2 for closing fitting recess by operating operation lever 21
0 in the fitting recess opening direction (see the phantom line in FIG. 3),
In this state, the fitting recesses 12 of the lower step bar fitting frames 8a and 8b are fitted to the lower step bar 2, and
The step bar 6b integrally connected to the upper step bar fitting frames 8c, 8d is stepped down and pressed down, so that the fitting recesses 12 of the upper step bar fitting frames 8c, 8d are fitted to the upper step bar 2. After the combination, the operation of the operation lever 21 may be simply released. Thereby, the entrance / exit of the fitting recess 12 fitted to the lower step bar 2 is closed by the fitting recess closing hook 20 (FIG. 3).
The portable ladder can be securely attached to the step bars 2 and 2 so as not to accidentally come off, and as shown in FIG. 9, it is possible to safely climb and descend along the portable ladder. When the portable ladder is to be removed from the step bars 2 and 2, the operation lever 21 is rotated to rotate the fitting recess closing hook 20 in the fitting recess opening direction, and then the portable ladder is moved upward. It can be easily removed just by pulling it up.

In the above embodiment, the case where the portable ladder is attached to the step bars 2 and 2 protruding from the inner wall surface 1a of the manhole entrance 1 has been described as an example. However, the present invention is not limited to this. It can also be attached to a step bar protruding from a concrete wall such as a dike or dam.

[0023]

According to the first aspect of the present invention, when the operation lever is operated and the hook for closing the fitting recess is rotated in the opening direction of the fitting recess, four step bars, up, down, left and right are fitted. After fitting the fitting recesses of the mating frame to the upper and lower two step bars respectively, simply releasing the operation of the operation lever closes the fitting recess by the hook, and the portable ladder is unexpectedly attached to the step bar. Since it can be securely attached so as not to come off, it is possible to climb up and down safely along the portable ladder, and the portable ladder can be easily removed from the step bar in the reverse procedure.

According to the second aspect of the present invention, the upper two step bar fitting frames of the four upper, lower, left and right step bar fitting frames are movable along the vertical girder.
A portable ladder can be easily attached to various step bars having different bar intervals according to the bar intervals.

According to the third aspect of the present invention, since the upper part of each of the two vertical beams is bent substantially in the shape of a letter toward the tip of the step bar fitting frame, the upper part of the ladder main body is bent. You can easily climb up and down along the mobile ladder without being disturbed.

According to the fourth aspect of the present invention, the cord is divided into an upper cord portion and a lower cord portion, and a cord moving length extension mechanism is interposed between the upper and lower cord portions. Therefore, the turning operation of the hook for opening and closing the fitting recess can be easily performed only by operating the operation lever small.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a portable ladder according to an embodiment of the present invention.

FIG. 2 is a rear view of the same.

FIG. 3 is a vertical sectional view of the lower step bar fitting frame on the lower side.

FIG. 4 is a plan view of the fitting frame.

FIG. 5 is a partially cutaway side view of both upper and lower step bar fitting frames.

FIG. 6 is a partially cutaway plan view of the fitting frame.

FIG. 7 is a longitudinal sectional view of the cable body moving length expanding mechanism.

FIG. 8 is a horizontal sectional view of the mechanism.

FIG. 9 is a side view showing a state where the ladder is attached to a step bar.

FIG. 10 is a longitudinal sectional view of a manhole.

[Explanation of symbols]

 1a Inner wall surface 2 Step bar 6 Ladder main body 6a Vertical girder 6b Stepping bar 8a, 8b Lower step bar fitting frame 8c, 8d Upper step bar fitting frame 12 Fitting recess 19 Spring 20 Fitting recess closing hook 21 Operation lever 22a Upper cable body part 22b, 22c Lower cable body part 23 Cable body movement length enlargement mechanism 25 Rotating rod

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hisao Nishio 2-5 Marunouchi, Takamatsu City, Kagawa Prefecture Inside Shikoku Electric Power Company (72) Inventor Yoshio Daimon 2-3-21 Higashitenma, Kita-ku, Osaka-shi, Osaka Nichido (58) Field surveyed (Int. Cl. ⁶ , DB name) E06C 1/00-1/58

Claims (4)

(57) [Scope of request for utility model registration] 1. A portable ladder attached to a plurality of step bars protruding from a wall surface at predetermined intervals in a vertical direction, comprising a pair of left and right vertical girders and arranged at predetermined vertical intervals between the two vertical girders. A ladder main body composed of a plurality of tread bars provided, and a downward fitting recess formed at a lower portion of each of the longitudinal beams at a predetermined interval in the vertical direction, and formed at a tip portion thereof is fitted to each of the two step bars. Four step bar fitting frames which are fitted together, and a fitting recess closing hook which is pivotally supported by the lower step bar fitting frames and is urged by a spring to close the entrance of the fitting recess. A portable ladder provided on an upper portion of the ladder main body and configured to rotate the hooks in a fitting recess opening direction against a spring via a cord body. 2. A lower step bar fitting frame is fixed to a vertical girder among upper, lower, left and right four step bar fitting frames attached to a lower portion of the both column girders, and an upper step bar is provided. 2. The portable ladder according to claim 1, wherein the fitting frame is movable along the longitudinal girder, and the upper two step bar fitting frames are integrally connected by a treadle. 3. The portable ladder according to claim 1, wherein the upper part of each of the two vertical girders is bent substantially in the shape of a letter toward the tip of the step bar fitting frame. . 4. The cord body is divided into an upper cord body part and a lower cord body part, and a cord body moving length expanding mechanism is interposed between the upper and lower cord bodies. The enlargement mechanism has a rotating rod pivotally supported by a vertical bar, a lower end of the upper rope portion is connected to a base end of the rotating rod, and a lower rope is connected to a distal end of the rotating rod. The portable ladder according to any one of claims 1 to 3, wherein an upper end of the body part is connected.