JPS58185892A - Prefabricated type ladder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to a ladder designed as a so-called prefabricated ladder consisting of several different parts that can be interconnected so that the effective length of the ladder can be adjusted and varied; the ladder according to the invention further comprises a profiled ladder. It can be manufactured from raw materials, sold in a broken and disassembled state, and assembled at the site of use.

There are many types of ladders made of different types of aluminum profiles on the market. However, these known ladders are manufactured and assembled at one and the same location. In this case, rivets are often used to connect the visible members of the ladder. This necessitates transporting the ladder fully assembled, which is expensive due to the expensive nature of the ladder, and where the purchaser of the ladder, even if he probably prefers the assembly process, cannot afford to do so. Even those who perform assembly work must pay for the assembly work. When handling or using a ladder in its entirety under diagonal loads, extremely strict conditions are required at the connection points of the ladder, and not only at the connections between different parts of the ladder.

This also applies to the connections (C) between different attachment members constituting one ladder section.Thus, in the case of conventional ladders in which different ladder sections are interconnected, e.g. by a catch, there are many conditions. may become extremely unstable.

In addition, conventional ladders are not immune to accidental disintegration even under load.

One type of loading that may be satisfactorily addressed is the torsion of a ladder about its longitudinal axis. Such loads can occur, for example, if the ladder is placed on uneven ground, one of the ladder's sides digs into the ground, or the top rung is placed on a corner of a building or a thin tree, etc. Like when you place a ladder with support.
This is when the support area is loaded asymmetrically. When a load is applied diagonally in this way, an extremely large load is naturally applied to the connecting parts of different ladder parts, but an even more troubling problem is the torsional load, or torsional stress, that occurs on the rungs themselves and the parts where they are fixed to the side timbers. be. Although the deformation of the rungs of the ladder and their fixings is slight, the considerable forces exerted on them make these details extremely important, especially if the ladder is made of easily deformed aluminum material. You need to pay great attention. For example, when ladders are interconnected using rivets, varying degrees of large loads are applied to these rivet connections as point loads, which immediately deforms the rivet connections and creates play, so that the ladder is not completely becomes unstable. Generally, when this happens, I adjust all the rivet connections.

It is impossible to reset.

The object of the present invention is that the set r can be manufactured as a simple kit,
Moreover, it can withstand extremely large loads that are often applied during use.
7. The object of the present invention is to realize a so-called prefabricated ladder having extremely high resistance.

According to the invention, this purpose is achieved by ensuring that each ladder section has a pair of side beams 1.
and a number of horizontal bars that can be fixed to these, both the side bars and the horizontal bars being constructed of profiled members, the side bars having a substantially closed longitudinal channel section 4 on the one hand and a longitudinally extending section on the other hand. In a prefabricated ladder having a protruding member 3, in which the protruding member 3 of one ladder part can be engaged with the channel part 4 of another ladder part with torsional rigidity and is slidable in the vertical direction, The cross section 2 has a closed cross-sectional profile.

At least one protrusion 15 is provided at each end of the rung, which can be inserted with torsional rigidity into the recess of the side wood 1 when the ladder is completely assembled, and the rung is secured to the rung by fixing means 16 separate from the protrusion 15. This can be achieved by press-fitting it to the side wood.

One embodiment of the ladder according to the invention is characterized in that the rungs have an asymmetrical and symmetrical cross-sectional profile and that the projections and the fixing elements are provided on mutually opposite sides.

A particularly simple and advantageous embodiment of the ladder according to the invention is characterized in that the projection consists of a part of the wall of the rung that projects from the end face of the rung, - eliminating the play between the different ladder parts, and In order to improve the sliding between these parts, in a further embodiment of the ladder according to the invention, the interconnected ladder parts can be connected to each other via a number of longitudinal guide ribs, preferably provided inside the channel part. It is characterized by guided sliding engagement.

The present invention will be described below with reference to the accompanying drawings, and the objects and features of the present invention will be easily understood from the following description.

In FIG. 1, the reference numeral 1 represents all the side pieces in two interconnected ladder sections, and 2 represents the rungs fixed to these side pieces. Thus, FIG. 1 is a detailed view of the two ladder sections viewed from below.

Also, as is clear from Figure 1, the cross section of the side tree is (1
It is constructed from an aluminum U-shaped member with a flexible shape. On one free shank of each side tree there are two projections 3 and on the other free shank there is a bend 4 forming a qualitatively closed channel. Furthermore, as is clear from FIG. 1, the protrusion 3 of one side tree is the channel/L of the other side tree.

4 and in this case consisting of profiles (l
tll One side of the tree is changed to the adjacent tree 4 /
It is inserted into L5. When all the side trees are interconnected in this way,
9111 At the same time the tree can move freely vertically.

Webs of profiled side members can be arranged in the same plane with respect to each other. This makes it possible to construct the ladder parts from the same parts and connect them to each other, so that according to the invention, the ladder can be constructed from many identical parts without having to change the upper part, center part, or lower part. It is possible to form.

The internal dimensions of the channel 4 are such that, with a relatively large play, the protruding part and the adjacent part of one yank T are accommodated in the channel 4 along the longitudinal direction. 1, provided that other foreign objects do not stop or interfere with the relative sliding movement between the cooperating aluminum parts of the two interlocking ladder parts;
However, in order for the ladder not to become unstable during use, it must be ensured that no play is actually formed due to the cooperative action of the side beams, and that in addition the torsional stress about the longitudinal axis of the ladder is It is important that there is effective transmission from one ladder section to another. For this reason, the side piece is provided with a number of guide ribs, of which two guide ribs 8 are provided on the outside of the second shank 9 of the side piece. In this way, the guide ribs 8 are provided inside the channel 4 so as to face each other. Furthermore, two opposing designs 1"l'Jb 10, 17'i are provided in the profiled channel 4, guiding the ladder parts laterally relative to each other.

The first shank 7 of the side wood whose all guide ribs are made of deformed material
Of course, it is also possible to provide the second shank 9 and the inside of the channel 4 flat. What is important is that the side beams exhibit mutually acceptable guiding action, while at the same time
without causing damage.

Also, be sure not to interfere with the mutual movement of the horizontal bars.

The best thing to do is to save a sui-suge for foreign objects.

As alluded to above, this type of ladder is subjected to many times greater compound loads when in use. An example of a simple load that acts symmetrically on a ladder is bending the entire ladder, but with only one bending plane (σ
It is parallel to the web 6 of the side tree. There is no need to worry about such a simple load. This is because very few important questions arise. On the other hand, if a load is applied diagonally to a ladder, for example, if one side tree sinks into the ground where it is installed, or if the ladder is installed with its top end leaning against a corner of a building or a thin tree, a load that is extremely difficult to evaluate will occur. In particular, troublesome loads occur when the ladder is subjected to torsional action about its vertical axis. This torsional action or rotation is transmitted to the crosspiece through the joint between the crosspiece and the side beam, and acts in the form of a torsional load. For this reason, it is important, on the one hand, that the cross-sectional configuration of the cross-piece exhibits torsional rigidity and, on the other hand, that the joint between the cross-piece and the side beam is capable of transmitting the torsional moments that occur. This is a particularly troublesome problem if we take into account that the main point of non-invention is to assemble the product at the site of use, or rather to manufacture and sell it in the form of a kit that cannot be connected by, for example, bathing. Furthermore, the material properties of aluminum materials, such as their softness, pose difficult problems. That's 1. When a ladder is loaded diagonally, localized loads tend to be very high and the material can therefore easily undergo permanent deformation and therefore play, resulting in instability of the ladder.

According to the invention, the crosspiece 2 is preferably manufactured in the form of a profile that can be extruded. The cross section of this profiled material must be such that it can absorb large loads in the vertical direction to the horizontal bars, and at the same time, the horizontal bars themselves must be able to withstand large torsional loads.

The cross-sectional shape of the horizontal rail shown in FIG. 2 was devised with the above in mind. That is, the two opposing vertical side walls 11 of the crosspiece according to FIG. 2 absorb large vertical loads. In order to reduce the risk of slipping, and to make the rung safer and easier to ride on, the upper surface 12 of the rung is of substantially flat and grooved construction. A screw socket 13 for accommodating a screw for joining the horizontal beam and the side wood is provided at an uneven part between the side wall 11 and the north face 12 of the horizontal beam. Furthermore, the lower surface 14 of the crosspiece 2 is also made substantially flat, thereby completely closing the entire cross section of the crosspiece. Flat lower surface 14
Therefore, the protruding tongue portion 15 extending over the entire width of the lower surface of the crosspiece can be easily realized by simple machining.

When the horizontal beam 2 is attached to the side wood, a pair of openings corresponding to the screw holes 13 are formed in the side wood, and the screws 15 can be passed through these openings. However, screw joints alone are not sufficient in terms of providing the necessary stability to the ladder, especially in terms of the torsion weight applied to the rungs.

For this reason, K uses the tongue portion 15 of the lower surface 14 of the crosspiece during assembly. Therefore, apart from the opening of the screw 16, an opening 13 is provided in the web 6 of the side tree 1, adapted to fit tightly with the tongue 15.

As described above, since the cross section of the horizontal beam 2 is completely closed, the resistance to torsional load is significantly increased.

Further, by setting the fixed points between the horizontal beam 2 and the side wood as far apart as possible, the effect of the load applied to the joint area can be completely reduced. In the present invention, the cooperation of the tongue 15 on the underside of the sidewall and the corresponding opening in the sidewall web 6 is of particular importance.

Therefore, the torsional V (stress) transmission capacity of the joint is increased, and the cross-sectional shape of the cross-section can be stabilized so that the cross-section does not deform at all even under conditions where a large load is applied.

The above-mentioned method of fully joining the crosspiece and the side beam is very advantageous. One reason for this is that the ladder can be simply and easily assembled directly at the location where the ladder is used without relying on special tools. Furthermore, according to the above-described joining method, high strength can be ensured even when a large load is applied. Finally, if the ladder is overloaded and damaged, the joint frame is easy to reset and realign. ladders with permanent fixings;
Especially in the case of ladders manufactured by folding or riveting, such a reset (
(reconstruction) and realignment are almost impossible.

Non-invention (1) Changes may be made without departing from the spirit and scope of the claims.7 Therefore, the invention shown in FIG.
It is also possible to use a horizontal cross-section having a cross-sectional shape slightly different from the cross-sectional shape. For example, it is also possible to configure the cross section of the cross-piece in such a way that the lower part of the side wall 11 is substantially straight, in which case a tongue corresponding to the tongue 15 is provided in this lower part. Also.

The protruding tongue at the end of the horizontal beam? Of course, it is also possible to provide them in other parts, or in some cases, in many other parts as explained above.However, if too many protruding tongues or too large protruding tongues are provided, Care must be taken, since the strength of the web 16 will be considerably weakened. .

[Brief explanation of drawings]

Fig. 1 is a partial view from below of two mutually connected ladder sections, and Fig. 2 is a view showing all the ends of the rungs, 1. side beams, 2. 3.Protruding portion, 4...Channel, 15...Protruding tongue, 16...Screw.

Claims (1)

[Claims] 11) Each ladder part is fixed to a pair of side trees 1 [1]
Consists of a large number of horizontal crosspieces, both the side wood and horizontal crosspieces are v4.
The side beams consist of a substantially closed longitudinal channel section 4 on the one hand and a longitudinally extending projecting member 3 on the other hand.
and a protrusion kA 3 ff of one ladder part:
In a prefabricated ladder that can be maintained with torsional rigidity within the channel part 4 of the other ladder parts, and is provided with a vertical blade lisuI/this sliding 11th function, the transverse cross section in which the horizontal rung 2 is closed It has a surface contour shape, and when assembling the ladder, the concave part (
at least one protrusion 1 which can be inserted with torsional rigidity;
5 is provided on each part Q' of the horizontal crosspiece, and apart from the protruding part 15, a certain means 166'' is used to press the horizontal crosspiece against the side wood. (2) The horizontal beam 2 has a non-rotating and symmetrical cross section, and the protrusion 15 and the fixing means 16 are disposed on the iJ side of each other. A prefabricated ladder according to claim 2. (3) A prefabricated ladder according to claim 2, in which the protruding portion 15 is a part of the wall material 14 of the horizontal crosspiece 2 protruding from the end face of the horizontal crosspiece 2. (4) Channel portion 4 The ladder part is preferably