The present invention relates to a beam for formwork systems.

The invention has application in the construction equipment sector, in particular in formwork systems, for example in the provision of floor castings, etc.

Nowadays beams for formwork systems are widespread, like the one shown in Figure 1. Such beam A has a cross-section that is symmetrical with respect to an axis B, which is vertical with respect to the illustration, with, in succession from above:

- a first portion C, conventionally the upper portion, with a U-shaped channel open upward for an optional filler of wood or of plastic and a pair of tabs D which extends laterally outward from the upper edges of the U- shaped channel,

- a core E of constant width,

- a second portion F with a cavity G open downward and tabs H which protrude toward the cavity, in order to keep the head of a screw inside it, and outward for resting the beam on other parts of the formwork systems.

Such beams have a number of drawbacks. First of all, the supporting capacity of the beam is limited by the low resistance of the core to bending, something that is often solved with short lengths which however might not satisfy the dimensional requirements of the system.

The limited supporting capacity implies a limitation in the uses of the beam.

The shape of the upper portion also limits the supporting capacity of the beam from the structural point of view and, as a consequence, it also limits the possible applications.

For example, in formwork systems for floor castings, on a vertical supporting structure of supporting towers, the beams are connected in pairs by way of connection elements such as forks. The pairs of beams constitute a primary framework, and a series of similar beams arranged on them in a transverse direction constitute a secondary framework. The formwork system is completed by wood planking. The beams of the secondary framework are provided with a filler of wood or of plastic in the special channels, which is adapted to create a connection with the planking in contact with the concrete, by way of nails.

The profiled elements known today do not ensure an optimal seal at the interface with the planking, since the upper portion of the beam is subject to separation from the planking if a force of a certain level is applied on it.

Also, the shape in cross-section of conventional beams prevents, or in any case limits, the possibility to connect some useful accessories to formwork systems, such as accessories for connecting to vertical safety railings and accessories for providing low-slung beams.

The aim of the present invention is to provide a beam for formwork systems which is capable of improving the known art in one or more of the above mentioned aspects.

Within this aim, an object of the invention is to provide a beam for the construction industry to be used in formwork systems, which has greater supporting capacity than conventional beams and is subject to deformability to a lesser extent.

Another object of the invention is to provide a beam that can be used in the connection of accessories to formwork systems.

A further object of the present invention is to overcome the drawbacks of the known art in an alternative manner to any existing solutions.

Another object of the invention is to provide a beam that is highly reliable, easy to implement and of low cost.

This aim and these and other objects which will become better apparent hereinafter are achieved by a beam for formwork systems, with a transverse cross-section that is symmetrical with respect to an axis of symmetry and which is characterized in that it has, in succession:

- a first portion with two C-shaped profiles, which are arranged mirror- symmetrically with respect to said axis of symmetry, with mutually opposite cores and cavities directed outward, connected by a plate for connection between two mirror- symmetrical wings thereof,

- a connecting element, which extends along the direction of said axis of symmetry, between said plate for connection and a base,

- a second portion with two protrusions which extend from said base and are provided with transverse end elements.

Further characteristics and advantages of the invention will become better apparent from the description of a preferred, but not exclusive, embodiment of the beam according to the invention, which is illustrated by way of non-limiting example in the accompanying drawings wherein:

- Figure 1 is a cross sectional view of a conventional beam;

- Figure 2 is a cross-sectional view of the beam according to the invention;

- Figure 3 shows a possible application of the beam according to the invention;

- Figure 4 is an enlarged view of the application shown in Figure 3;

- Figure 5 is a detail of the application shown in Figure 3;

- Figure 6 shows another application of the beam according to the invention;

- Figure 7 is a detail of the application shown in Figure 6;

- Figure 8 shows a further application of the beam according to the invention;

- Figure 9 shows another application of the beam according to the invention;

- Figure 10 shows yet another application of the beam according to the invention.

With reference to the figures, and in particular to Figure 2, the beam according to the invention, generally designated by the reference numeral

10, has a transverse cross-section that is symmetrical with respect to an axis of symmetry 11 and has, in succession:

- a first portion 12 with two C-shaped profiles 13, which are arranged mirror- symmetrically with respect to the axis of symmetry 11, with mutually opposite cores 14 and cavities directed outward, connected by a plate for connection 15 between two mirror- symmetrical wings 16 thereof,

- a connecting element 17, which extends along the direction of the axis of symmetry 11, between the plate for connection 15 and a base 18,

- a second portion 19 with two protrusions 20 which extend from the base 18 and are provided with transverse end elements 21.

With reference to Figure 2, the C-shaped profiles 13 each have an upper wing 16a and a lower wing 16.

The wings 16 are the lower wings, connected by the plate for connection 15, and each one has a circular portion for blending with the respective core 14 of the C-shaped profiles 13.

The two C-shaped profiles 13 provide, with the plate for connection 15, a U-shaped channel in which a filler of wood or of plastic can be present, to which optional wood planking of formwork systems can be fixed.

The connecting element 17 is tubular and shaped like an elongated trapezoid, with two bases constituted by the plate for connection 15 and by the base 18, cited previously, therefore respectively at the first portion 12 and at the second portion 19, and with two mirror- symmetrical sides 22.

The protrusions 20 extend from the base 18 as downward extensions of the mirror- symmetrical sides 22 and the transverse end elements 21 are positioned along a direction perpendicular to that of the axis of symmetry

11.

The base 18 and the two protrusions 20 define a cavity 23 and the portions of transverse elements 21 directed toward each other make it possible to keep the head of any screw used in formwork systems in the cavity 23.

Use of the beam, according to the invention, is the following.

The beam can be used, as in the prior art, in formwork systems for floor castings. In a system of this type, the beams 10 are fixed horizontally on a vertical supporting tower by way of connection elements. The formwork system is completed by fixing a wooden planking on the beams.

The first portion 12 of each beam 10, with the channel filled with a profiled element of wood or of plastic, is adapted to create a connection with the planking. The planking is connected with the profiled element of wood or of plastic mainly with nails, and the profiled element in turn is connected with the beam 10 with a number at will of bolts arranged mainly in a transverse direction in the first portion 12, so as to render the two C- shaped profiles 13 and the profiled element of wood or of plastic integral. By virtue of the particular shape of the first portion 12, the beam 10 supports the planking with better performance than conventional beams, even for relatively high loads. The particular cross-section of the beam 10, with the two C-shaped profiles 13, ensures a more effective seal and overall the formwork thus obtained is more rigid.

Figures 3 to 7 show other possible applications of the beam 10 according to the invention, applications which with conventional beams are difficult to carry out.

Figure 3 shows a safety railing fitted using the beam 10 according to the invention.

In particular, there is a horizontal framework which is obtained with a series of parallel beams 10 above a vertical supporting structure. The beams 10 are all arranged with the first portion 12 upward.

In the enlargement in Figure 4, the connection of the railing to the beams 10 by way of devices 24 is more clearly visible.

The devices 24 are conventional per se and each one of them comprises a substantially C-shaped profile 25, with wings 25a folded in for an end portion to define a seat in which the first portion 12 of a beam 10 is adapted to be positioned, and a tubular element 26 extending at right angles from the C-shaped profile 25 for connection to an upright 27, with which protection planks 28 are associated. The wings 25a are positioned below the wings 16 of the first portion 12 of beam 10, as shown in Figure 5.

Figure 6 shows the application of the beam 10 according to the invention in the provision of low-slung beams.

In this case too a device 29 is used which is conventional per se. It is composed of a triangular frame positioned with a horizontal part with a C- shaped cross-section above the first portion 12 of the beam 10. On the horizontal part there is a bracket 30 which can be adjusted by way of a threaded tension member 31 and a wing-nut 32. The bracket 30 has the lower wings 30a folded in so as to define a space in which the first portion 12 is adapted to be positioned. The wings 30a are folded in below the wings 16 of the beam 10, as shown in Figure 7.

The formwork system is completed by way of the insertion, in the concavity of the vertical profile of the triangular frame, of a wooden batten 33, which is connected by nailing. A plank 34 of wood is connected to such batten 33 and is adapted to define the surface of the low-slung concrete beam.

The beam 10 according to the invention, by virtue of the greater supporting capacity than conventional beams, can be used in further applications, such as: formwork systems for floor slabs with significant cantilevered parts (like the example shown in Figure 8), formwork systems for wall castings (Figure 9), and formwork systems for pillar castings (Figure 10).

For example, in formwork systems for wall castings, beams 10 are arranged vertically and a layer of wood is associated with them on the side of the first portion 12. Horizontal beams made of steel are associated with the beams 10 at the second portion 19.

It is evident that the tubular shape of the connecting element 17 and the particular shape of the first portion 12, with the wings 16, give the beam 10 less deformability and a greater supporting capacity than conventional beams, and that use of the beam 10 is made possible in applications for which to date it was difficult, or even ruled out, to use beams of the same type. The beam 10 according to the invention is easily adopted with devices known today and in use for formwork systems.

In practice it has been found that the invention fully achieves the intended aim and objects by providing a beam for formwork systems that has greater supporting capacity than conventional beams and is subject to deformability to a lesser extent, and which lends itself to being used for connecting to accessories for formwork systems.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Application No. 102018000009730 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.