CZ301983B6 - Structural element, use thereof and process for its manufacture - Google Patents

Abstract

In the present invention, there is disclosed a structural element especially a faþade element that separates a cold area (5) from a warm area (6), with a frame stiffener having a hollow box-type section (11) of synthetic material and with a beam (1) arranged therein between the cold area (5) and the warm area (6), which has an outer beam part (2) adjoined to the cold area (5) and an inner beam part (3) adjoined to the warm area (6), wherein the beam (1) being produced from steel as the only material is arranged inside the hollow chamber of the box-type section as reinforcement thereof. The beam (1) is provided between the outer beam part (2) and the inner beam part (3) with rows of openings arranged in offset manner to each other. There is also disclosed a process for manufacturing the above-described structural element wherein the production process comprises forming a beam (1) of a sheet metal and simultaneously creating the mutually offset openings. The beam (1) can be used as an insulation element between cold and warm areas.

Description

Structural element, its use and method of its production

Technical field

The invention relates to a structural element, in particular a facade element which separates the cold area from the warm area, with a frame reinforcement having a hollow chamber profile of synthetic material and a beam arranged therein between the cold area and the warm area having an outer beam member associated with the cold and an inner beam member associated with the warm region, the beam 10 being made of steel as a single material and arranged within the hollow chamber of the hollow chamber profile as reinforcement.

The invention also relates to the use of this component as well as to a method for manufacturing the component.

BACKGROUND OF THE INVENTION

Such structural elements can also serve for sound insulation. Thereafter, the cold zone 20, respectively the warm zone, corresponds to the spaces between which sound insulation is to be provided.

The component closest to the species in question is known from EP 117 308 A. However, there is a strong heat transfer from the hot region to the cold region.

Furthermore, a construction element according to German Utility Model DE 296 10 652 U1 is known. In this component, a beam is provided in the hollow chamber profile of synthetic material, which consists of metal and synthetic material. The arrangement of this beam within the hollow chamber profile of synthetic material shows that the beam between the outside of the window element and the inside of the window element is arranged in such a way that one beam is facing the cold outer region and the other beam is generally warmer. Between them lies a molded part of synthetic material which reduces the heat transfer from the inner beam to the outer beam. The metal outer and inner support metal parts thereby provide sufficient stability, and the synthetic molded part lying between them is firmly held by the cold-rolled inner or outer beam member, so that a one-piece beam member is formed of two different materials.

This known reinforcing profile for hollow plastic profiles ensures that the heat transfer values on the window frame can drop significantly. However, the production of the cross-linking profile is relatively costly, since different materials must be joined together in such a way that sufficient stability can be ensured even with strong temperature differences.

It is furthermore known from EP-A 0 553 688 to use as large as possible extrusions with the greatest possible surface area to reduce the heat transfer through the steel profile in connection between the outer and inner side of the profile. Since this necessarily takes place at the expense of stability, stiffeners are provided which hold the inner and outer supporting members together so that structural requirements for structural analysis can be met. However, the proposed large-scale material removal and the associated weakening of the profile structure can significantly reduce existing safety margins, especially for dynamic loads.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a structural member with a carrier which is suitable for use as a reinforcement of the hollow chamber profile and is, on the one hand, manufactured at low cost and, on the other hand, provides good heat transfer reduction with little stability.

- 1 GB 301983 B6

SUMMARY OF THE INVENTION

This task is solved by a structural element, especially a façade element that separates the cold? an area from a hot area, with a frame reinforcement having a hollow chamber profile of synthetic material and a beam disposed therein between the cold area and the warm area, having an outer beam portion assigned to the cold area and an inner beam portion assigned to the hot area; It is made of steel as a single material and is arranged inside the hollow chamber of the hollow chamber profile as reinforcement, which according to the invention is characterized in that the beam has offset rows of openings between the outer beam part and the inner beam part.

The component according to the invention thus has a beam which can be made of a single material, such as a rolled steel sheet, and yet has considerably reduced heat conduction properties. This is achieved either by providing a frame beam part between the outer and inner girder part, which extends, for example, in the form of a protrusion into the interior of the hollow profile of the frame beam made of synthetic material, or the heat conducting cross-section lying between the inner and outer girder. many through holes.

Thus, the beam of a structural member according to the invention can be manufactured as a conventional traditional beam from a single material, such as steel, and the heat transfer is not reduced by another beam part but by a special shaping of the beam or frame beam surrounding the beam. The shaping of the beam can be cheaply changed during the manufacturing of the beam or thereafter in a simple manner without incurring additional costs due to the joining of the various materials. In addition, there are no problems in the joining area between the various materials of the component according to the invention, although the temperatures in the façade area vary greatly and the material used is subject to strong expansion and contraction.

Since hollow profiles of synthetic material are generally extruded, small variations in the mold design can achieve a cheap change in the shape of the hollow chamber profile. This makes it possible to arrange the protrusions or webs within the hollow chamber profile in such a way that the protrusions or webs keep the beam members spaced apart from one another.

Advantageously, the offset rows of holes disposed relative to each other lie in the region of the neutral fiber of the beam. Each beam has a heavier and less heavily loaded area, depending on its loading method. Especially in the case of façade elements, alternating loads often occur on the beam, which are applied in particular to the edge regions of the beam, while the beam region lying between them is much less loaded. There is a neutral fiber in this region, and in order to reduce the stability of the beam as little as possible, it is proposed to cut or reduce the cross-section on the beam directly in this region.

Advantageously, the beam is reinforced by multiple laying of the sheet metal part outside the neutral fiber. In this case, the sheet metal part preferably has a thickness greater than 0.5 mm.

The simple production of rows of holes is made possible by the rows of holes being produced by material removal. For this purpose, for example, holes can be drilled or cut in the neutral fiber region. These openings are preferably arranged such that there are still only small webs between them. Although these webs are sufficient for the required strength, they reduce the heat transfer very much compared to the material used hitherto.

Especially when cold-formed sheets are used, perforated sheets can be used as the base material for the beam. Such a sheet has reduced strength over the entire sheet region. However, this can be compensated for by the shaping of the beam and in particular by the parallel arrangement of multiple sheet metal layers in the heavily loaded areas of the beam. Thus, in a limited, thermally conductive

Preferably, the monolayer perforated sheet remains, while in the adjacent regions, a higher degree of stability is achieved by forming the sheet.

Alternatively or additionally, the rows of apertures may also be formed by shaping the material. Certain cuts or die cuts on the beam allow for the displacement of certain areas of the beam from the plane of the beam to reduce heat transfer.

Particularly in the manufacture of façade elements, such as windows or beams arranged between windows, it is advantageous if the outer and inner beam members are fastened to the hollow chamber profile preferably by means of at least one projection or at least one web. This allows the beam members to be kept at a certain distance from each other without touching the beams, and without using additional parts to keep the beams at a certain distance. Since the hollow chamber profile is generally made of synthetic material and thus has a lower heat transfer coefficient than a steel beam, fastening to the hollow chamber profile results in sufficient attachment of the beam members and at the same time to insulation between the beam members.

A preferred field of application of the component according to the invention is to use as a window frame or sash. In this case, the beam lies between the colder outer side of the facade and the warmer inner side of the facade, so that the embodiment according to the invention can optimally reduce heat transfer between these sides.

In a preferred embodiment, the construction element has two hollow chamber profiles and a beam is arranged between them. This leads to the fact that the beam is arranged outside the hollow chamber profiles but is protected by these hollow chamber profiles arranged on both sides. The beam has both a static function as a support element and a function as a coupling between the hollow chamber profiles which is formed by the connection between the two hollow chamber profiles and the beam arranged between them.

Advantageously, the beam has a shape that allows the position of the insulating element to be adjusted. The beam can be foamed on its inside with insulating material. According to the invention, however, it is envisaged that the insulating molding is inserted into the beam in such a way that its position is adjusted according to the position of the beam. Positioning is to be understood as determining the position of the insulating body relative to the beam while maintaining displaceability in the longitudinal direction of the beam. Depending on the desired situation, the displaceability of the insulating body in the longitudinal direction of the beam can also be suppressed by shaping the beam.

The described positioning can be achieved in a simple manner by having three beams arranged at right angles to one another. These three surfaces make it possible to insert the insulating body in a simple way into the beam and to determine the position of the insulating body by shaping the beam.

By means of a form closure or force closure between the sides of the beam and the insulating body, the insulating body is more or less firmly connected to the beam.

The object of the invention is also solved by the use of a structural element having, in the region of its neutral fiber, offset rows of openings arranged relative to one another as an insulating element between the cold area and the warm area.

In a method of manufacturing a structural member, the beam is formed from sheet metal, and according to the invention, offset rows of apertures are formed when the sheet metal is formed. The beam is surrounded by one or more profile sections made of synthetic material, the heat conducting cross-section is reduced with a certain shape of the sheet. The beams according to the invention are preferably manufactured from cold-rolled sheet metal. It is possible during this forming process, optionally directly before or after it

to form rows of apertures according to the invention. This makes it possible to combine the working step of the forming with the working step of reducing the thermally conductive cross-section. The production of such a beam is therefore only slightly more expensive.

A particularly advantageous method of manufacturing the beam according to the invention is to use a perforated sheet metal as the sheet. This allows the production process to remain unchanged. By using the perforated sheet, the thermally conductive cross-sectional area is reduced in the connecting area between the inner and outer parts, without further action being necessary.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of beams, hollow chamber profiles and facade elements according to the invention are shown in the figures and will be explained in more detail in the following description. Figures 15, 16, 17, 19 and 23 are examples which are not included in the claims and are not exemplary embodiments of the invention. However, these examples allow a deeper understanding of the invention.

In the accompanying drawings, the figures show the following:

Fig. 1 is a perspective view of the beam; Fig. 2 is a perspective view of the beam shown in Fig. 1 inside the hollow chamber profile of synthetic material; Fig. 3 is a perspective view of the beam formed as a connector; Fig. 4 is a perspective view of the beam shown in Fig. 3 in a built-in state between two hollow chamber profiles of synthetic material; Fig. 5 is a perspective view of a single beam with three rows of elongated holes on the base surface; Fig. 6 is two perspective views of single beams with a triple row of elongated holes in the shoulder region; Fig. 7 is a view of a U-shaped beam with an embossed hole; Fig. K is a cross-sectional view of a beam with a 11-shaped profile; 7, FIG. 9 is a cross-sectional view of the region of the beam openings; FIG. 10 is a longitudinal cross-section of the beam member shown in FIG. 9; FIG. Fig. 12 is a longitudinal cross-sectional view of the beam member shown in Fig. 11; Fig. 13 is a cross-sectional view of a third region of the beam apertures; Fig. 14 is a longitudinal section of the beam member shown in Fig. 13; Fig. 15 shows two cut-outs from a beam with a single taper of the cross-section; Fig. 16 shows two cut-outs from a beam part with a double row depression;

Fig. 17 shows two cut-outs of a beam section with a triple-row depression, Fig. 18 shows the arrangement of offset rows of triangular holes on a U-shaped beam, Fig. 19 shows the arrangement of circular holes on a beam with a profiled beam U-shaped, Fig. 20 shows offset arrangement of square holes on a U-shaped beam, Fig. 21 shows cross-sections of different reinforcement profiles, Fig. 22 shows cross-sections of particularly stable reinforcement profiles Fig. 23 is a cross-sectional profile of a joining beam with a single row of holes; Fig. 24 is a cross-sectional profile of a joining beam with a double row of holes; 25 is a plan view of the profile shown in FIG. 25 and hollow 28 is a cross-section of a hollow chamber profile with a C-shaped profile; FIG. 29 is a cross-section of a hollow chamber profile with a rectangular profile; FIG. 30 is a cross-section of a hollow chamber profile; Fig. 31 is a cross-section of a hollow chamber profile with a narrow U-shaped profile; Fig. 32 is a cross-section of a hollow chamber profile with a U-shaped profile with triple folded arms; Fig. 33 is a cross-sectional view of a C-shaped hollow chamber profile with triple-folded C-shaped arms; Fig. 34 is a cross-section of a C-shaped hollow chamber profile with six-folded arms; is a cross section of a hollow chamber profile with a beam with a triple folded special profile in the shape of a letter Fig. 36 is a cross-sectional view of the hollow chamber profile with a U-shaped beam and a large air space between the beam and the inner wall of the hollow-chamber profile; Fig. 37 is a cross-sectional view of the hollow chamber profile with a U-shaped beam. the folded arms and the narrow air space between the arms and the inner side of the hollow chamber profile, FIG. 38 is a cross-section of the hollow chamber profile with U-shaped beam members,

Fig. 39 is a cross-section of a hollow chamber profile with U-shaped beam sections with triple sides of the arm; Fig. 40 is a cross-section of a hollow chamber profile with a U-shaped beam section with six-fold sides Fig. 41 is a cross-section of a frame and leaf profile with mutually insulated beam members, and Fig. 42 is a cross-section of a hollow chamber profile with two opposing C-shaped beam sections, Fig. 43 is a hollow cross-section. a chamber profile with two opposing, partially folded, C-shaped beam members; FIG. 44 is a cross-section of two opposing, six-fold, L-shaped beam members.

Fig. 45 is a cross-sectional view of a hollow chamber profile with two opposing L-shaped beam sections; Fig. 46 is a cross-sectional view of a hollow chamber profile with two opposing LJ-shaped beam sections; and Fig. 47 is a cross-sectional view. cross-section of hollow chamber profile with two L-shaped girder sections,

DETAILED DESCRIPTION OF THE INVENTION

The beam 1 shown in FIG. 1 has an outer beam part 2 and an inner beam part 3 which are connected to each other by a web 4. The outer beam part 2 is generally facing the colder cold area 5 and the inner part is generally facing the warmer. In this case, the web 4 has a screw channel 7, and on each side of the screw channel are disposed through each other longitudinal through holes 8 which reduce the thermally conductive cross-section lying in the web 4. In addition, in order to reduce the heat transfer, longitudinal openings 9 are also provided on the outer girder part, which define the heat transfer from the hot regions 6 to the cold regions 5 on the interposed webs 10.

Fig. 2 shows how the beam 1 shown in Fig. 1 can be inserted into the hollow chamber profile 11. The beam 1 thus serves as a reinforcement of the hollow chamber profile 11. For this purpose, the beam f is fastened by the side walls 12 of the cavity formed in the profile, as well as the webs 13 and the projections 14. Also in the built-in state, the beam 1 lies between the cold region 5 and the warm region 6 in such a way that the web 4 bridging The beam members 2 and 3 act as a reduced heat transfer region in cross-section.

In the present case, the beam 1 has been inserted into the hollow chamber profile 11 in such a way that the head 15 of the beam 7 faces the warm region 6 and the heel 16 towards the cold region 5. However, the beam 1

5o can be inserted into the hollow chamber profile 11 also rotated through 180 degrees and in this position also performs the task of reducing heat transfer in comparison with conventional synthetic reinforcement profiles.

-6cl 30i983 Bo

Giant. 3 shows a beam 20 which can be inserted as a coupling between two hollow chamber profiles. To this end, the beam 20 has ribs 21, 23, 24 on both sides which cooperate with the hollow chamber profiles of synthetic material. Between these ribs 21 and 22, respectively 23 and 24, there is always a screw channel 25 or 26 into which the screws can be screwed or the profiles can be inserted. The ribs 21-24 and the profile walls forming the screw channels 25 and 26 increase the stability of the beam 20 in opposing regions, and between them is a web 27 in which the neutral fiber 28 of the beam 20 lies. longitudinal openings 29 to reduce the thermally conductive cross-section. In addition, further longitudinal openings 30 and 31 are arranged parallel to the offset longitudinal holes 29 in the web 27 to further reduce heat transfer.

The construction of the façade element by means of two hollow chamber profiles 32, 33 and a connecting beam 20 between them is shown schematically in FIG. 4. In this case, U-shaped profiles 34, 35 are arranged in the hollow chamber profiles 32, 33 in order to increase the stability of the hollow sections. In order to reduce the heat transfer, longitudinal openings 36, 37, 38, 39 are provided at the base of the U-shaped profiles 34. 35 Between the hollow chamber profiles 32 and 33 there is a connecting beam 20, which is supported by uprights 21 to 24. engages in recesses 40 within the hollow chamber profiles 32 and 33, respectively.

Thus, the longitudinal openings 36-39 in the U-shaped profiles and the longitudinal opening 29 in the connecting profile ensure a reduction in the heat transfer from the cold region 5 to the warm region 6, without substantially reducing the stability of the beams 34, 35. 20.

Examples of U-shaped beams used in Fig. 4 are shown in Figs. 5 and 6.

These beams show that several longitudinal openings can be arranged side by side and offset relative to one another in order to limit the heat transfer between the cold side and the hot side.

Giant. 7 and 8 show the possibility of placing through holes or regions reducing heat transfer. As can be clearly seen from FIG. 8, only one cut 44 is placed in the beam for this purpose and the beam areas 42, 43 following the cut 41 are subsequently extruded so that the heat transfer area is reduced.

FIGS. 9 to 14 show various possibilities for the heat transfer to be arranged in the beam. In all of the illustrated embodiments, cuts are arranged in the beam and the region between them is shaped.

Giant. 15 to 17 show examples in which the thickness of the beam sheet is reduced by notches or constrictions. This also reduces the heat transfer area.

Giant. Figures 18 to 20 illustrate the possibilities of recesses or shaping on a beam. There are various variation possibilities in the manner of arranging the shaping or through holes and their shape. The illustrated examples of a triangle, a circle and a square, as well as the arrangement of one or more adjacent rows, show that there are a number of possibilities for forming a beam according to the invention.

Giant. 21 shows various beam shapes and positions 50-57 at which the thermally conductive cross-section is preferably reduced in such beam shapes.

Further possibilities of forming beam profiles are shown in FIG. 22, in which areas are indicated

60 to 80 reduced cross-section.

Also in the connection profiles of the beams, there are different types of location of the cross-section reducing regions. 23 to 26 show exemplary embodiments for single-row, double-row and three-row punched row arrangements.

- 7 GB 301983 B6

Various embodiments for the production of reinforcing profiles, which are usable in hollow chamber profiles of synthetic material, are shown in FIGS. 27 to 47. In this case, the frame frame parts have been shown with the reinforcing profile used. Correspondingly, however, similar reinforcing profiles can be used in the sash section as well. This is illustrated by the exemplary embodiment shown in FIG. 40.

Giant. Figures 27 to 31 show simple profiles which are curved in a U, C or rectangular shape and are adapted to the cavity of the hollow chamber profile. These beam sections have a cross-section reduction 81 approximately in the region of the neutral fiber, and by means of a screw, the beam profile elements 83 are attached to the frame section 84. The ribs and webs 85 to allow the support 83 to be firmly gripped in the hollow chamber profile 84. However, these ribs may also be advantageously used to provide a distance between the inner wall 90 of the hollow chamber profile 84 and the support 9f. This distance can be - as shown on i? Fig. 31 - used as an insulating air space which is formed between the beam 92 and the inner wall of the profiled part 84. For this purpose, the U-shaped beam 92 is fastened by ribs and webs 85 to 89 so that it is between the beam 95 An adequate insulating space 97 is provided on the opposite side between the beam member 99 facing the hot region 98 and the inner wall 93 of the profiled hollow chamber member 84.

Giant. 32 to 37 show that the beam members may be made of cold formed metal sheets. In this case, it is possible to lay the metal sheets one over the other several times in order to create a statically more stable beam. Advantageously, the beam outside the neutral fiber thus has a thicker cross-section than in the thermally conductive cross-section 102 lying between the inner and outer beam members 100 and 101, respectively. This reduced area can be further reduced by through holes or material shaping. To this end, a through hole 103 is shown in FIG.

Further Figures 33 to 37 show that different profile shapes can be reinforced by a multilayered design of the beam member, thereby automatically reducing the thermally conductive cross-section lying therebetween.

Giant. Figures 38 to 47 show that heat transfer can also be reduced by providing a frame reinforcement portion 1111 between the first beam member 110 and the second beam member 120.

12. This member 111 is formed as a T-rib and separates the beam members 110 and 120 from one another, while at the same time taking up the anchoring of the beam members within the hollow chamber 11 of the hollow chamber profile 112. In order to prevent sliding of the beam members 110 and 120 In the longitudinal direction of the hollow chamber profile 112, screws 114 and 115 are provided which extend through the hollow chamber profile 112 and each one of the beam members 110 and 120, respectively.

Giant. Figs. 39 to 40 show exemplary embodiments corresponding to Fig. 38 in which the girder parts are reinforced.

The interaction of the frame reinforcement 121 with the sash reinforcement 122 is shown in FIG. 41.

It will be appreciated that the beam members shown in the frame reinforcement example can also be used in the sash frame. In the illustrated embodiment, the beam members 12, 12 and 125, and 125 and 126 respectively are supported by L-shaped holders 127, 128 and 129, 130.

Further exemplary embodiments of the beam members and brackets are shown in Figs. 42 to 47, wherein the ribs or L-shaped brackets on the hollow chamber profile serve to retain the single-layer or multilayer beam members in the hollow chamber profile cavity at a particular location. distance to each other.

- 8 GB 301983 B6

The component 140 shown in FIG. 48 has a substantially U-shaped beam 141 whose arms 142, 143 are laid double in the end regions to increase stability. The legs 142 and 143 in the present case form the outer beam and the inner beam, and the underlying surface forms a reduced beam 14 in cross-section. The cross-section reduction is achieved by a particular beam shape as shown in Figures 9 to 14. ,

The U-shaped cross-sectional area of the beam forms a bounded cavity in which the insulating body 145 is arranged. The size and shape of the insulating body are adapted to the U-shaped beam so that the insulating body can be inserted into the beam and then held by the arms 142 and 143.

Giant. 49 shows that a more stable beam can be achieved by repeatedly bending the metal sheet. Said exemplary embodiment relates to a substantially L-shaped beam 150, which is placed next to the other L-shaped beams 151, can be inserted into a (not shown) frame reinforcement. The insulating bodies 152 and 153 are held by the sides of the L-shaped beam 150 and 151, respectively, and the short holding arm 154 and 155, respectively.

This makes it possible to freely combine the girder parts, as shown, for example, in Figs. 48 and 49, in order to achieve sufficient stability of the frame and at the same time prevent heat transfer.

The shaping and number of layers allow high variability in the dimensioning of the beams.

The described beams can be used without an insulating body. However, a further increase in insulation can be achieved by using insulating bodies. The insulating bodies are simply plugged into the beam profile and fastened there by force. Then, a combination of beam and insulating body can be inserted into the hollow body synthetic profile to improve stability and insulating properties.

Claims (16)

PATENT CLAIMS A structural element, in particular a facade element, which separates the cold area (5) from the warm area (6), with a frame reinforcement having a hollow chamber profile (11) of synthetic material and a beam (1) disposed therein between the cold area ( 5) and a warm region (6) having an outer beam member (2) associated with the cold region (5) and an inner beam member (3) associated with the warm region (6), wherein the beam (1) is made of a single steel and is arranged within the hollow chamber of the hollow chamber profile as a reinforcement. n a c u j ϊ c ϊ s c 11 m, zc the beam (1) has arranged rows of holes disposed between the outer beam member (2) and the inner beam member (3). A component according to claim 1, characterized in that the rows of openings lie in the neutral fiber region of the beam (1). -9EN 301983 Bo A component according to claim 1 or 2, characterized in that: that the beam (1) is reinforced by multiple laying of the sheet metal part. io A component according to claim 3, characterized by a thickness greater than 0.5 mm. 5. A component according to any one of the preceding claims, wherein the rows of apertures are produced by material removal. A component according to any of the preceding claims, wherein the beam (1) has a perforated sheet. 7. A component according to any of the preceding claims, wherein the rows of holes are formed by shaping the material. with it. The sheet metal part of the claims, characterized by the claims, characterized by the claims The component according to claim 7, characterized in that the outer and inner beam members (2, 3) are preferably fastened to the hollow chamber profile (11) by at least one projection (14) or at least one web (13). A component according to any one of the preceding claims, characterized in that the component is a window frame or a sash. A component according to any one of the preceding claims, characterized in that 2s. The structure element has two hollow chamber profiles (32, 33) and a beam (20) is arranged between them. A component according to any one of the preceding claims, characterized in that the beam (1,20) has a shape adapted to adjust the position of the insulating element. A component according to claim 11, characterized in that the beam (1, 20) has three surfaces arranged at right angles to one another, Component according to either of Claims 11 or 12, characterized in that 55 has an insulating element which is adjacent to the beam (1, 20) on three surfaces arranged at right angles to one another. Use of a structural element according to any one of the preceding claims, wherein the beam (1, 20) has arranged rows of openings disposed relative to one another in the region of its neutral fiber (28), such as 40 of an insulating element between the cold area (5) and the warm area (6). Method for manufacturing a component according to any one of claims 1 to 13, wherein the beam (I) is formed from sheet metal, characterized in that offset rows of apertures are formed relative to one another during sheet forming. Method according to claim 15, characterized in that perforated sheet metal is used as the sheet.