JPS6221677Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a connection structure between a support such as a ladder and a step.

Conventionally, as shown in FIG. 2C, the connection between the support and the step of a ladder was performed using rivets or the like, and caulking work was performed at both ends of each step, resulting in low assembly efficiency. The present invention improves productivity by eliminating any caulking work, and provides a strut-to-step joint structure that has high durability and is highly workable. Examples will be described below with reference to the drawings. FIG. 1 is a front view of a folding ladder, in which the posts and steps are connected by a conventional riveting method. Figure 2 A,
B is a cross-sectional view in FIG. 1 of the ladders connected according to the present invention. FIG. 2C is a sectional view of the conventional method. Although the ladder in FIG. 1 is an example of a folding type ladder, it is not limited to the folding type, and the present invention can be widely applied.

Mainly in FIG. 2A, numeral 1 is a column having a substantially U-shaped cross section, and 2 is an outer plate of the column, which corresponds to a web having a U-shaped cross section. That is, a pair of hollow box-shaped flanges 3 are integrally extruded with the outer plate 2 toward the inner side from both the front and rear ends (the upper and lower ends in the figure) of the outer plate 2. In the embodiment, the support column 1 is made of an extruded aluminum alloy member. A longitudinal opening 7 is provided on the surface of one flange 3. In this embodiment, as described above, since the extruded shape is used, the opening 7 is formed at the same time as the support column 1 during extrusion without any special machining. 6 is a step, and the shape of the step does not matter, but the figure shows a rectangular tube or U-shaped step, and its tip is fitted between the front and rear (top and bottom in the figure) flanges 3, and is pre-drilled in the support at regular intervals. The support column and the step are connected by inserting a connecting pin 4 through an opening 7 provided on the surface of one flange 3 by aligning the through hole provided in the step with the through hole drilled in the step. Reference numeral 5 indicates a gap created between the tip of the step 6 and the inner wall of the outer plate of the support 1, but in the case of a fixed ladder, there is no need to provide a gap. In the folding type, since the step 6 rotates around the connecting pin 4, it is necessary to provide some play and cut out a relief at the tip of the step 6. 8 is a blind body made of a highly elastic material such as soft synthetic resin or rubber, and has uneven stripes 8a formed on its surface for the purpose of preventing slipping. On both left and right sides of the blind body, narrow grooves 8b are provided in the longitudinal direction so that the blind body can be fitted while holding the opening edge of the flange 3. When a desired number of steps 6 are connected to the column 1, the opening 7 is sealed with a blind body 8, and at the same time, the bottom of the blind body comes into contact with the end surface of the aforementioned connecting pin 4.

FIG. 2B shows a different embodiment of the opening 7, in which the blind body is a band-shaped aluminum plate inserted into a narrow groove formed at the edge of the opening.

With the structure as explained above, when assembling a ladder, etc., there is no need for rivet crimping work to connect the pillars and steps, which are standard parts that are mass-produced in factories, and it is extremely easy to assemble ladders without the need for skilled workers. It is simple and reduces the number of assembly steps, and since the flange 3 formed integrally with the outer plate (web) is rectangular and hollow, it has added rigidity as a support, and is suitable for long work. In addition, if it is made of aluminum alloy, it is lightweight and easy to transport, and when the ladder is placed against the eaves, etc., if the side with the anti-slip blind body 8 is used in contact with the side, the ladder will not slip and will increase stability. The surface is not dotted with protrusions such as rivet heads, which greatly improves the aesthetic appearance and makes a great practical contribution.

[Brief explanation of drawings]

FIG. 1 is a front view of the ladder, FIGS. 2A and 2C are sectional views of the connecting portion according to the present invention, and FIG. 2C is a sectional view of the conventional method. 1... strut, 2... outer plate, 3... flange,
4... Connection pin, 6... Step, 7... Opening,
8...Blind body, 8a... Surface uneven pattern.

Claims (1)

[Claims for Utility Model Registration] (1) A step 6 is disposed between a pair of columns 1 and 1 that are opposite each other and have a U-shaped cross section, and both ends of the step are inscribed in the respective columns and pivoted with a connecting pin 4. In the supporting ladder, the pair of opposing flanges 3, 3 of the U-shaped cross section made of an extruded aluminum alloy section are integrally formed in a hollow box shape, and only one of the pair of flanges is formed on the outer surface of the flange. A longitudinal opening 7 is provided in the face plate, and pin holes are provided in advance in the inner surface plates of the opposing flanges, and after the pins are inserted through the openings 7 to pivotally support the step, the openings are closed in the blind body 8. A connection structure between a sealed column and steps. (2) The blind body 8 has a pair of longitudinal narrow grooves 8b on the left and right sides sandwiched between the opening edges by an elastic body made of synthetic resin, and has uneven stripes 8a on the surface. Connection structure between the pillar and step described in 1).