EP0019598A1

EP0019598A1 - Improvement in high resistance extruded panels and containers made with them

Info

Publication number: EP0019598A1
Application number: EP80830028A
Authority: EP
Inventors: Emilio Benvenuti; Enzo Maria Notargiacomo
Original assignee: Selenia Industrie Elettroniche Associate SpA
Current assignee: Leonardo SpA
Priority date: 1979-05-17
Filing date: 1980-05-15
Publication date: 1980-11-26

Abstract

The present invention refers to high resistance extruded panels and to the containers made with them.

The panels realized bythistechniquedemonstrate a satisfactory rigidity. Their internal structure is placed obliquely with respect to the plane of the panel forming a series of isosceles triangles having alternativelythe base on one plane of the panel, and the vertex on that opposite, every pair of successive triangles also having an oblique common side. This structure is such that any portion of the panel contained by any two section parallel to each other and orthogonal to the direction of the extrusion behaves as a reticular beam, thus conferring on the panel characteristics of high resistance.

Description

The present invention refers to high resistance extruded panels and to the containers made with them.
An extrusion technique is known of directlyproducing panels formed of two flat sheets of suitable material, suitably spaced and connected to each other by means of a series of stiffening struts which give rigidity to the whole structure.
The panels realized by this technique and known upto the present time are characterized by internal stiffening struts parallel to one another and orthogonal to the surface planes of the panel.
This structure while demonstrating a satisfactory rigidity in the direc tion of the estrusion remains lacking in resistance to bending in the direction orthogonal to it.
To overcome this problem which results in a disadvantageous irregularity in the known panels of the present technique,recourse is made, in accord ance with this invention, to a new arrangement of the internal ribbing which is placed obliquely with respect to the plane of the panel. Each rib is connected to each of the two planes that contain the panel along the line from which the next parts, In this way a structure is determined consisting of a series of isosceles triangles having alternately the base on one plane of the panel and the vertex on that opposite, every pair of successive triangles also having an oblique common side. This structure is such that any portion of the panel contained by any two sectionsparallel to each other and orthogonal to the direction of the extrusion behaves as a reticular beam, thus conferring on the panel characteristics of high resistance also in this direction.
Finally the panel exhibits, by means of this arrangement of the ribbing, as a characteristic of the present invention, a resistance to bending and to shearing practically equal both in the direction of the extrusion and in that orthogonal to it.
The panels constructed in accordance with the principles now described fend themselves ideally not only to the realization of containers of every type and dimension, having particulary notable characteristcs of resistance, but also to the realization of industrial products for building, for the mechanical industries and the motor-vehicle industry, etc.
Still within the confines of this invention a particularly robust container has been realized which exploits the features of the panels here in described in a special way.
To give a better understanding of the following part of the description reference is made to the drawings where Fig. 1 shows an orthogonal section of a panel in accordance with the invention, Fig.2 a corner element, Fig.3 a connecting element and Fig.4 an example of the connection of these elements.
It should be emphasized that the various elements can be joined to one another by welding, rivetting, with adhesives or with specially designed clip joints.
Now considering Fig.4 it should be borne in mind that the element illustrated in Fig. 1 together with the two straight pieces of the corner elements connected to it is used to construct one of the sides of the container. If we suppose that this side is subject to a uniform load, every section of it, as stated previously, will behave as a fixed reticular beam simply subject to a uniform load.
It is known that along this beam the bending moment will be such that in two particular sections of the beam it reaches nulls.
The relative lengths of the element in Fig. 1 and of the sides of the corner elements in Fig. 2 have been specially calculated so that the areas of the joints occur in the aforsaid sections of minimum force on the sides of the container.
Still referring to Fig. 1 it may be noted that the two extreme ribs of the panel are provided with two nail-shaped struts, placed on the opposite sides of the rib at a preset distance from the point of junction with the external planes of the panel.
The purpose of these struts is as follows. When it comes to the joining of the various elements of the container by riveting it is necessary to make two series of holes along the lines parallel to the direction of the extrusion corresponding to the zones indicated with arrows in Fig. 1. These holes must affect not only the external walls of the panel but also the cblique ribbing. This would present a certain difficulty in the making the holes due to the fact that the drill would be deviated by the said oblique surfaces. The presence of the struts in providing a support for the point of the drill overcomes this disadvantage.
in order to minimize the weight of the panel, rendering its resistance ba maximum, it has been found that in a preferred form of the invention the above-mentioned isosceles triangles forming the reticular beam must have angles at the base of 50° 15' and the angle at the vertex of 79⁰ 30'. The two triangles at the extremes of the panel element of Fig.1, however, are slightly different and have the angles respectively of 50°15', 84°45' and ⁴5°.
This invention has been illustrated only by way of example and not in a limiting sense, and can contain within its area of protection variations and modifications in the form and in its structure.

Claims

1. High resistance extruded panels formed by two parallel planes joined to each other and reinforced by means of ribs and characterized by the fact that the said ribs are placed obliquely with respect to the said planes, each rib having the connecting lines with the said parallel planes in common with the two adjacent to it so as to realize a structure consisting of a series of isosceles triangles, in the section trans verse to the direction of the extrusion, having alternately the base on one plane of the panel and the vertex on that opposite, also with each pair of successive triangles having an oblique side in common.

2. High resistance panels as in claim 1 characterized by being formed by an extrusion of aluminium alloy.

3. High resistance panels as in claim 1 characterized by being formed by an extrusion of plastic material.

4. High resistance panels as in claim 1 characterized by the fact that the said isosceles triangles have-base angles of 50° 15' and the vertex of 79° 30'.

5. Panel linear element realized in accordance with the preceding claims in which the said end triangles have angles respectively of 50° 15', 840 45' and 45°.

6. Panel corner element realized in accordance with claims 1 to 4 formed by two panel elements placed at right angles.

7. Panel linear element in accordance with claim 5 characterized by the fact that in each of the two end ribs two nail-shaped struts are provided, one inside and one outside, having the purpose of providing a support for the point of the drill when the holes for rivetting the joint are made.

8. Panel element in accordance with claims 6 and 7 characterized by the fact that the ratio of the length of the panel element to the angle and the length of the linear element is such as to make the connecting section at the said elements coincide with the bending moment null when the said linear element is joined to two of the corner elements and loaded with a uniformly distributed load.

9. Container realized by means of the panel elements of the preceding claims.