JPH0242719Y2 - - Google Patents

Description

[Detailed description of the invention] (1) Industrial application field The present invention relates to a multi-stage telescoping ladder for raising and lowering a workbench carrying cargo or personnel along the ladder.

(2) Prior Art A multi-stage telescopic ladder in which a plurality of ladders each consisting of a pair of channel members with openings facing each other are fitted together in a telescopic manner is described in, for example, Japanese Patent Laid-Open No. 59-57899. This is conventionally known.

(3) Problems that the invention aims to solve However, because conventional multi-level extension ladders have openings, their rigidity against torsion is low, and when a flange is provided at the opening to increase rigidity, it causes damage to the side of the workbench. There was a problem that the directional play became large.

(4) Means for Solving the Problems In order to solve the above problems, the present invention uses a plurality of ladders, each of which is made up of a pair of channel members with openings facing each other, fitted together in a telescopic manner. In a multi-stage extension ladder, two opposing channel members
The outer ladder has the upper edge of the channel member bent toward the outside of the ladder, and the inner ladder has the upper edge of the channel member bent toward the inner side of the ladder.

(5) Effect With the above configuration, by bending the ends of the two opposing sides of the channel member, the rigidity against torsion is increased, and the horizontal play of the workbench is reduced to the outside of the outer ladder. regulated by the folded part or the inward folded part of the inner ladder.

(6) Examples Examples of the present invention will be described below with reference to the drawings.

FIG. 2 shows a load carrying work vehicle equipped with a multi-stage telescoping ladder according to the present invention.
The base end of the multi-stage telescoping ladder 4 is pivotally supported, and the multi-stage telescoping ladder 4 is extended and contracted by a telescoping device (not shown), and is also raised and lowered by an undulation cylinder 6. It is installed to move up and down.

FIG. 1 is a cross-sectional view showing the configuration of a multi-stage telescoping ladder 4, in which the lower surfaces of a pair of channel members 11 and 12 with openings facing each other are connected by a cross member 13, and a first ladder 10 has an opening on the upper surface. inside the
A second ladder 20 configured similarly to the first ladder, a third ladder
The ladder 30 and the fourth ladder 40 are fitted in order in a telescopic manner, and the top edges of the two opposing sides of the opening of each ladder are directed toward the outside of the ladder in the first ladder 10 and the second ladder 20. Flanges 14, 15, 24, 25 bent at approximately right angles are formed in parallel, and in the third ladder 30 and fourth ladder 40, flanges 34, bent at approximately right angles toward the inside of the ladder, 35, 44, and 45 are formed in parallel, and is a conventionally known expansion/contraction device (not shown).
Accordingly, the second ladder 20, the third ladder 30, and the fourth ladder 40 extend and contract simultaneously with respect to the first ladder 10. On the upper surface of the multi-stage telescoping ladder 4, there is a work platform 5 that moves up and down along the multi-stage telescoping ladder 4 by means of left and right rollers 6, 7 and rollers 60, 70 that roll on the channel members of each ladder and rollers 60, 70 that roll along the inner peripheral surface of the channel members. is provided.

With the above configuration, the extension ladder 4 is undulated and expanded/contracted, the tip of the extension ladder 4 is pressed against a window frame of a building, etc., and the workbench 5 on which the cargo is placed is raised and lowered along the extension ladder 4, thereby increasing the height of the cargo. Each ladder 10, 20, 30, 40 has a flange 14, 15,
24, 25, 34, 35, 44, and 45 have increased torsional rigidity, so the telescopic ladder 4
As shown in Figure 3, the twisting of the
Since the lateral movement of the roller 6 is regulated by the flange 14 or 24, and the lateral movement of the roller 60 is regulated by the flange 44 or 34, the play on one side of the workbench 5 is
The play a between the flanges 14 and 24 becomes the play B between the flanges 44 and 34, and the play on the other side of the workbench 5 is also regulated by the rollers 7, 70 and the flanges 15, 25, 45, 35 in the same way as above. and the play a between the flange 14 and the flange 24 is
Since the play b between the flange 44 and the flange 34 is located in the same range, the lateral play of the workbench 5 is significantly reduced compared to the case where the flanges of each ladder are bent in the same direction.

(7) Effects of the invention As described above, according to the invention, the rigidity of a multi-stage telescoping ladder can be increased with a simple structure, and the lateral play of the workbench that goes up and down along the ladder can be reduced. Therefore, the present invention is effective in improving the safety of multi-stage extension ladders.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a sectional view of a multi-stage telescoping ladder, Fig. 2 is a side view of a load carrying work vehicle equipped with a multi-stage telescoping ladder, and Fig. 3 is a detailed view of the main parts. . 4...Multi-tier extension ladder, 5...Workbench, 6,7,
60, 70...roller, 10...first ladder, 20
...Second ladder, 30...Third ladder, 40...Fourth
Ladder, 14, 15, 25, 34, 35, 44, 4
5...Flange.

Claims (1)

[Scope of utility model registration request] In a multi-stage telescopic ladder in which a plurality of ladders each having a pair of channel members with openings facing each other are fitted together in a telescopic manner, the tips of the two opposing sides of the channel members are connected to the tips of the two opposing sides of the channel members, and the outer ladder is connected to the tips of the upper side of the channel members. A multi-tiered telescopic ladder characterized in that the inner ladder has the top end of the channel member bent towards the inside of the ladder.