Construction element

Abstract

 Construction element (1), comprising at least two strips (6,7,8) joined by at least a longitudinal union. At least one of said strips has one or two crenellated longitudinal edges (4) with alternating projections (9) and recesses (10). Each longitudinal union between strips is made between projections (9) of at least one crenellated longitudinal edge (4) of one strip (6,7) and at least a stripe for longitudinal union (3) belonging to other strip (6,7,8). The number of strips (6-7) having one or two crenellated longitudinal edges (4) is less than or equal to the number of strips (6,7,8) which have stripes for longitudinal union (3).

Description

Object of the invention

[0001] The present invention relates to a construction element, in the form of a profile, comprising two or more strips joined by longitudinal unions. Said strips can be formed in different shapes to allow the creation of profiles of various sections, with a considerable saving of material and improving its properties.

[0002] The construction element of the invention is applicable, for example, in forming the frame for partitions and claddings using prefabricated panels.

Background of the invention.

[0003] Elements for construction of the type disclosed are described for example in US5661881, in which the profile is composed of two strips which are obtained by slitting a band of sufficient width, as a sinuous line which creates, in both strips, adjacent crenellated longitudinal edges, with projections and recesses. The two strips obtained, once separated, are joined together by the projections of the crenellated longitudinal edges.

[0004] A similar construction element is described in W020111038860.

[0005] In both cases, the union between strips which form the profile or construction element is made by the projections of the crenellated longitudinal edges, by partial overlap thereof, leaving the line joining the two strips at approximately the center of the web of the profile obtained by the union of these strips. This circumstance implies a resistance problem that can be the cause of collapse of the profile.

[0006] Furthermore, the profiles obtained with the mentioned systems have a rigid section, which favors the transmission of vibrations between the elements mounted on either side of the profile. This problem is particularly important when the construction element is used in the formation of frames for walls with prefabricated panels.

Description of the invention

[0007] The present invention relates to a construction element, consisting of a profile comprising at least two strips that are joined together by means of at least a longitudinal union.

[0008] According to the invention, at least one of these strips has one or two crenellated longitudinal edges with alternating projections and recesses. Each longitudinal union between strips is made between projections of at least one crenellated longitudinal edge of one strip and at least one stripe for longitudinal union belonging to other strip.

[0009] According to another feature of the invention the number of strips having one or two crenellated longitudinal edges is less than or equal to the number of strips which have at least one stripe for longitudinal union.

[0010] The stripe or stripes for longitudinal union may be located along the longitudinal central zone of the strip to which they belong.

[0011] Also, the stripe or stripes for longitudinal union may be limited by a non-crenellated longitudinal edge.

[0012] According to a possible embodiment the longitudinal union between strips is made between projections of a crenellated longitudinal edge of one first strip and at least two stripes for longitudinal union, belonging to a second strip, separated transversely to each other. In this case said projections can have opposite transversal slopes.

[0013] The union could also be made between projections of crenellated longitudinal edges of a first strip with two crenellated longitudinal edges and at least one stripe for longitudinal union, belonging to a second strip.

[0014] In order to strengthen the construction element, both the strips and the projections of the crenellated longitudinal edges may have reinforcing protrusions.

[0015] For certain applications, the construction element may include at least one strip having at least one non-crenellated longitudinal edge finished as a toothed edge.

[0016] The construction element may be composed of only two strips, one of which presents a crenellated longitudinal edge and is joined longitudinally, by the outer end of the projections from its crenellated longitudinal edge, to a stripe for longitudinal union belonging to one of the surfaces of a strip without crenellated longitudinal edges. Construction elements with sections of different shapes can be achieved depending on the shape of each strip.

[0017] Also the construction element may be composed of three or more strips, with one or more strips having at least one of their longitudinal edges crenellated, forming, as in the previous case, sections of different shapes.

[0018] One of the strips that form the construction element may have two longitudinal edges crenellated, and join, by the outer end of the projections on either longitudinal edge, to two strips without crenellated longitudinal edges. In this way, I-shaped, C shaped, Z shaped, omega, etc. profiles can be achieved.

[0019] Throughout the document, the term "longitudinal union" should be understood as a join between strips along its whole length, regardless of whether this join is made continuously or in isolated sections, by means of occasional or localized connections along its whole length. Likewise, the term "stripe for longitudinal union" should be understood as a continuous zone, delimited by two parallel lines, which runs along the surface of one strip without any interruption, regardless of whether on this "stripe for longitudinal union" the "longitudinal union" is made continuously or in isolated sections.

[0020] The projections of each crenellated longitudinal edge can make contact, with the surface of the strip to which are joined, along a single stripe for longitudinal union or along more stripes for longitudinal union, separated transversely to each other. In the second case, the projections can have different slopes, for example alternately opposite transversal slopes, enabling the section of the construction element to be not completely rigid, but having a certain capacity for transverse deformation, which also spreads along the construction element, providing a spring effect which will reduce or dampen vibration transmission across the profile and between the panels or elements fixed to said strips.

[0021] This circumstance is particularly important when the construction element is used in the formation of frames for partitions using prefabricated panels, since such construction elements will reduce the transmission of vibrations and sounds from the rooms located on either side of the partition.

[0022] As a means of reinforcing, the strips in the construction element may have deformations which may run along the strip and / or on the projections of the crenellated longitudinal edges.

[0023] The join between the outer end of the projections and the stripe for longitudinal union of the strip, can be made by welding, soldering, sewing or stitching, clinching, folding, bending, pressure, clipping, gluing, riveting, etc.

[0024] All the projections of one or both crenellated longitudinal edges, belonging to one strip, may be of equal size. Also, the projections of one or both crenellated longitudinal edges, belonging to one strip, may be of different size.

[0025] Furthermore, the strips with one or two crenellated longitudinal edges can be obtained from a band of greater width, through one or more longitudinal cuts, of sinuous path, with straight or curved sections, in order to obtain two or more strips with crenellated longitudinal edges. By this cutting system it is possible to obtain strips with one or two crenellated longitudinal edges.

Brief description of the drawings

[0026] The accompanying drawings show possible shapes of construction elements, given by way of non-limiting examples, and obtained according to the invention.

[0027] Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It should be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention.

[0028] In the drawings, wherein similar reference characters denote similar elements throughout the several views:

Figure 1 is a perspective view of a construction element comprising two strips.

Figure 2 is a rear elevation view of the construction element of figure 1

Figure 3 is a side view of the construction element of figure 1.

Figure 4 shows the flat pattern development of the two strips from which is formed the construction element Figure 1.

Figure 5 shows a partial perspective of a construction element consisting of three strips.

Figure 6 shows an alternative embodiment of a similar profile to that shown in figure 5.

Figure 7 is a cross section of the construction element, according to the line VII-VII of figure 6.

Figure 8 is a view, similar to Figure 5, showing a construction element with a different section.

Figures 9 and 10 show in perspective and cross section, according to the line X-X of figure 9, respectively, an alternative embodiment of the profile of Figure 8.

Figure 11 shows a partial perspective of a construction element consisting of five strips, having an omega shape.

Figure 12 shows a partial perspective of a construction element consisting of three strips, having a Z shape.

Figure 13 is a cross section of the construction element according to the line XIII-XIII of figure 12.

Figure 14 shows in perspective a variant of the profile shown in figure 5.

Figure 15 shows one possible way of union between strips.

Figure 16 shows in perspective a construction element of closed-section, obtained according to the invention.

Figure 17 shows in perspective a variant of the a construction element of closed-section.

Figure 18 shows in perspective a variant of the profile shown in figure 17.

Figures 19a to 19c' represent schematically a possible process for obtaining strips with one or two crenellated longitudinal edges

Figures 20 to 22 show in side elevation, vertical cross section, according to the line XXI-XXI of figure 20, and horizontal cross section, according to the line XXII-XXII of figure 21, a similar profile as shown in Figure 6, in the resting state.

Figures 23 to 25 are views, similar to Figures 20 to 22, showing the same profile in loading state.

Figure 26 shows, in plan view, a possible configuration of a strip with two crenellated longitudinal edges.

Figure 27 is a section of the same strip, according to the line XXVII-XXVII of figure 26.

[0029] The following is a list of references used in the subsequent detailed explanation of the drawings and in the detailed descriptions of the invention.

1. Profile

3. Stripe for longitudinal union

4. Crenellated longitudinal edge

5. Non crenellated longitudinal edge.

6. Strip with one crenellated longitudinal edge

6'. Flat strip with one crenellated longitudinal edge

7. Strip with two crenellated longitudinal edges

8. Strip without crenellated longitudinal edges

8'. Flat strip without crenellated longitudinal edges

9. Projections

10. Recesses

11. Outer end

12. Tab.

14. Reinforcing protrusions

15. Reinforcing groove

16. Bottom of the groove

17. Longitudinal folds

19. Web of the profile

20. Flange of the profile

21. Lateral fold.

23' -23". Planes of the projections with different slope

25. Band.

27. Contact edge

28. Toothed edge

29. Longitudinal central zone

30. Longitudinal lateral zone

31. Longitudinal cuts

Detailed description of the invention

[0030] Figures 1 to 3 show a profile (1) formed according to the invention, which is composed of two strips (6, 8), joined together by a longitudinal union.

[0031] The development of the strips (6,8), shown in Figure 4, corresponds to the flat strips (6',8'), of which one of the flat strips (6') has a crenellated longitudinal edge (4), with projections (9) and recesses (10) alternating, and the other flat strips (8') has two non-crenellated longitudinal edges (5).

[0032] On the flat strips (6', 8') longitudinal folds (17) are performed, represented in the figure 4 by dotted lines. Once the strips (6', 8') are folded, by these longitudinal folds (17), and joined together, the section of the construction element of figure 3 is obtained.

[0033] Once folded the flat strips (6', 8') by the longitudinal folds (17), a strip with a crenellated longitudinal edge (6) and a strip without crenellated longitudinal edges (8) are obtained, respectively. The strip with a crenellated longitudinal edge (6) is joined to the surface of the strip without crenellated longitudinal edges (8) by the outer ends (11) of the projections (9) of the crenellated longitudinal edge (4). In the case shown in figures 3 and 4, the outer ends (11) of the projections (9) are folded according to a longitudinal fold (17) and make contact with a stripe for longitudinal union (3) on the surface of the strip without crenellated longitudinal edges (8).

[0034] In an alternative embodiment, figure 15, the projections (9) of the strip (7) will form tabs (12) which can pass through the strip (8) and join onto a stripe for longitudinal union (3). Connections to said strips can be made by welding, soldering, sewing or stitching, clinching, folding, bending, pressure, clipping, gluing, riveting, etc.

[0035] In the case of figures 1 to 4, a construction element, in the form of a profile (1) made from two flat strips (6 ', 8'), is obtained. The first strip (6'), which has one crenellated longitudinal edge (4), is joined to the second strip (8'), which has two non-crenellated longitudinal edges (5). The union between strips is made between the outer end (11) of the projections (9), which form the crenellated longitudinal edge (4) of the first strip (6'), and a stripe for longitudinal union (3) of the second strip (8').

[0036] Using the described system, construction elements in the form of profiles (1), composed of two or more strips, can be obtained.

[0037] Thus, Figure 5 shows a construction element in the form of a profile (1) consisting of three strips, a central strip with two crenellated longitudinal edges (7) and two external strips without crenellated longitudinal edges (8).

[0038] As in the previous case, the crenellated longitudinal edges (4) of the strips with two crenellated longitudinal edges (7) have projections (9) and recesses (10). Said projections (9) are joined to the strips (8) by means of the outer ends (11) of said projections (9).

[0039] Also the construction element of figure 5 is obtained from flat strips, similarly to that described with reference to Figures 1 to 4. In this case, the outer ends (11) of consecutive projections (9) are oriented alternately in opposite directions but are located in the same plane.

[0040] In both embodiments described, the projections (9), of each crenellated longitudinal edge (4), are coplanar with each other and, likewise, their outer ends (11) make contact on a common stripe for longitudinal union (3) of a strip (8).

[0041] However the projections (9) may have different slopes, for example alternately opposite transversal slopes with respect to the longitudinal central zone (29) of said strip (7). Said projections (9) are located in two different planes and are joined to two stripes for longitudinal union (3), separated transversely to each other, belonging to the same strip (8)

[0042] This is the case of construction elements in the form of a profile (1) shown in Figures 6 and 7, comprising an equal number of strips that the profile of Figure 5, a central strip with two crenellated longitudinal edges (7) and two external strips without crenellated longitudinal edges (8).

[0043] In the case of Figures 6 and 7 the projections (9) of each crenellated longitudinal edge (4) have alternately opposite transversal slopes with respect to the longitudinal central zone (29) of said strip (7). Thus, the projections (9) of each crenellated longitudinal edge (4) are located in two planes (23', 23"), Figure 7, and make contact on two stripes for longitudinal union (3), which are separated transversely to each other, belonging to the same strip (8)

[0044] Using the three strips that compose the construction element in the form of a profile (1) of Figure 5, a construction element with different section could be also obtained, as shown in Figure 8. In this case, the projections (9), of both crenellated longitudinal edges (4), are completely flat and are joined by their outer ends (11) to the surface of the lateral folds (21) of the strips (8), which define the stripes for longitudinal union (3).

[0045] Figure 9 and 10 show the same construction element of figure 8. In this case, the projections (9) of the two crenellated longitudinal edges (4) take an arrangement similar to that described with reference to Figures 6 and 7. The projections (9) of each crenellated longitudinal edge (4) have alternately opposite transversal slopes, as best seen in Figure 10. Said projections (9) are located on planes (23 ', 23") with different slope and make contact on opposite surfaces of the lateral fold (21) of the strip (8), to which they are joined from a different side.

[0046] In all cases, the union between the outer ends (11) of the projections (9) and the stripes for longitudinal union (3), either located on the surface of the strips or on the surface of the lateral folds (21), can be made by soldering, riveting, clinching, clipping, bending and pressure, etc.

[0047] Figure 11 shows a construction element in the form of a profile (1) in omega, consisting of five strips. Two of these strips are strips with two crenellated longitudinal edges (7), with alternate projections (9) and recesses (10), while the other three strips are strips without crenellated longitudinal edges (8).

[0048] The strips with two crenellated longitudinal edges (7) take the same configuration as the central strip (7) of Figure 8, with the projections (9) of the two crenellated longitudinal edges of each strip (7) in a same plane and making contact along the same side of the lateral folds (21) of the strips (8). As can be understood, the projections (9) can adopt the same arrangement, with alternately opposite transversal slope, described with reference to Figures 9 and 10.

[0049] Figures 12 and 13 show another construction element in the form of a profile (1) with Z-shape, also composed of three strips. As in the case of Figures 5 to 10, having a central strip with two crenellated longitudinal edges (7) and two external strips without crenellated longitudinal edges (8), the central strip having alternate projections (9) and recesses (10). Said projections (9), of each crenellated longitudinal edge (4), have alternately opposite transversal slopes with respect to the longitudinal central zone (29) of said strip (7). The outer ends (11) of the projections (9), belonging to one crenellated longitudinal edge (4), make contact alternately by opposite surfaces of the lateral fold (21) of the strips (8). The surfaces of the lateral fold (21) define the two stripes for longitudinal union (3). Figure 13, shows how the projections (9) of each crenellated longitudinal edge (4) are located in two planes (23 ', 23") with opposite transversal slopes.

[0050] Figure 14 shows a construction element in the form of a profile (1), similar to Figure 5, being the only difference that the strips (8) with non crenellated longitudinal edges (5) are finished as a toothed edge (28). These toothed edges (28) are designed to facilitate and/or improve the mounting or union between the construction element in the form of a profile (1) and other components of the system. The teeth of the toothed edges (28) can adopt different geometries, may also take the form of hooks.

[0051] The toothed edges (28) can adopt configurations different from that shown, that facilitate the assembly of the panels, either directly or via intermediate auxiliary pieces.

[0052] Figure 15 shows one possible form of union, whereby a first strip without crenellated longitudinal edges (8) has deformations in the form of reinforcing groove (15). The bottom (16) of said reinforcing groove (15) is traversed by tabs (12) belonging to the projections (9) of crenellated longitudinal edge (4) of a second strip with two crenellated longitudinal edges (7). Said tabs (12) pass through slots made in the bottom (16) of the reinforcing groove (15) and the contact edge (27), limited between tabs (12), is in contact with the bottom surface (16) of the reinforcing groove (15) of the first strip (8).

[0053] Figure 16 shows a construction element in the form of a profile (1) of closed section, comprising two equal strips (6) with a crenellated longitudinal edge (4), with two longitudinal unions. Said strips (6) present two longitudinal folds (17) that determine in each strip a lateral fold (21), a central zone (29) and a lateral zone (30) with a crenellated longitudinal edge (4), with projections (9) and recesses (10). The projections (9) of a first strip (6) are joined to a stripe for longitudinal union (3) of the lateral fold (21) of the second strip (6) and, similarly the projections (9) of the second strip (6) are joined to a stripe for longitudinal union (3) of the lateral fold (21) of the first strip (6).

[0054] Figure 17 shows a construction element in form of a profile (1) of closed section, similar to the construction element of figure 16, but in this case composed of a strip with two crenellated longitudinal edges (7) and a strip without crenellated longitudinal edges (8) provided with two stripes for longitudinal union (3). The projections (9) of each crenellated longitudinal edge (4) are joined to a stripe for longitudinal union (3), belonging to a lateral fold (21), by any of the aforementioned forms of union. Both the lateral zones (30) and the lateral folds (21) may not be parallel to form construction elements of different section to that shown in Figure 17.

[0055] In figure 18 is shown a construction element, similar to the construction element of figure 17, composed of a strip with two crenellated longitudinal edges (7) and a strip without crenellated longitudinal edges (8). In the strip (7), the projections (9) are sloped with respect to the lateral zone (30). The projections of each crenellated longitudinal edge (4) have opposite slopes, converging together, and are joined to the strip (8) along to contiguous stripes for longitudinal union (3), belonging to said strip (8). The outer end (11) of the projections (9) of the two crenellated longitudinal edges of the strip (7) may join the strip (8) on one stripe for longitudinal union (3). Also the projections (9) may have opposite slopes divergent, joining the outer ends (11), of the projections of the two crenellated longitudinal edges, on to parallel stripes for longitudinal union (3).

[0056] As is shown in figures (19a-19c), the strips can be obtained from a band (25) of greater width, by longitudinal cuts (31) thereof. For example, in Figure 19a is shown a band (25) in which are performed three longitudinal cuts (31), Figure 19b, with sinuous path, formed in this case by straight runs, which allow obtaining strips with two crenellated longitudinal edges (7), with alternate projections (9) and recesses (10). As shown in Figure 19c, the strips (7) may be of the desired width, depending on the width of the band (25).

[0057] On the band (25), Figure 19a, a single central longitudinal cut (31) may be performed, Figure 19b ', which would permit to obtain two strips with only one crenellated longitudinal edge (6), Figure 19c'. The strips with a crenellated longitudinal edge (6) could be used in the production of construction elements similar to that described with reference to Figures 1 to 4 and 16. While the strips with two crenellated longitudinal edges (7) could be used for the construction of construction elements in figures 5 to 15 and figures 17 to 18.

[0058] In all cases described, there is at least one strip having at least one crenellated longitudinal edge (4).

[0059] In all cases, each union between strips is made between projections (9) of at least one crenellated longitudinal edge (4) of a strip and at least one stripe for longitudinal union (3) belonging to another strip.

[0060] Also, in all cases, the number of strips having one or two crenellated longitudinal edges is less than or equal to the number of strips which have at least a stripe for longitudinal union.

[0061] The configuration of Figures 1, 6, 9, 12 and 18 has the further advantage that the section of the construction element is not completely rigid, but offers some capacity for transverse deformation.

[0062] In Figures 20 to 22 is shown, in simplified form, the construction element in the form of a profile (1), similar to Figure 6, in a resting state. The longitudinal central zone (29) of the strip with two crenellated longitudinal edges (7) is completely flat and the projections (9), of each crenellated longitudinal edge (4), are located in different planes (23 ', 23"), having alternately opposite transversal slopes.

[0063] In Figures 21 and 22 is shown the position of the projections (9) and the longitudinal central zone (29) of the strip that, as mentioned, is completely flat.

[0064] Figures 23 to 25 represent the same construction element (1) under load. In this situation, both the projections (9) and the longitudinal central zone (29) of the strip are deformed, with a slight curvature, reducing the distance H between the external strips (8). The longitudinal central zone (29) of the central strip (7) adopts, along said strip, a slightly sinuous path as shown in section in Figure 25. Thus, a spring effect is achieved, which reduces the transmission of vibrations between external strips (8), improving their mechanical and acoustic behavior against impact, pressure or seismic actions.

[0065] This circumstance, as indicated above, is particularly important when the construction element is used in the formation of structures or frames for partition composed of prefabricated panels, which are fixed to each side of the structure, for example, fixed on the strips (8) of the construction elements (1). The spring effect of the constructive elements in the form of a profile (1) described will reduce the transmission of noise and, generally, vibrations between dwellings or spaces on either side of the partition walls.

[0066] A further advantage is that this solution achieves a reduction in the thermal transmission between strips, because there is no continuous contact along them, as contact is reduced to the occasional or localized connections between projections (9) and the stripe for longitudinal union (3) of the strips.

[0067] When the construction element (1) includes a strip with two crenellated longitudinal edges (7), for example as shown in Figures 5 to 7, a profile(1) is obtained (1) that works similarly to an articulated structure or truss, with greater efficiency, compared to a profile having a continuous section along its whole length. Thus, less material is required, which represents a reduction in weight and power consumption in its manufacture, with the consequent environmental and economic benefits.

[0068] In the particular case of profiles working like a articulated structure or truss, as shown in Figures 5, 6, 14 and 18, the articulated joints are of particular importance, which are obtained by the type of joint shown in Figure 15, in which the tabs projecting (12) pass through the strip (8).

[0069] Also in the case in which the construction element in the form of a profile (1), for example as shown in Figures 5 and 6, that includes a strip with two crenellated longitudinal edges (7), an advantage is obtained by reducing the thickness of said strip (7), which constitutes the web (19) of the profile (1).

[0070] Likewise, said central strip (7) or web (19) may be of a different length to the length of the external strips (8) or flanges (20) of the profile (1). When the length of the strip (7) is less than the length of the strips (8), said central strip (7) or web (19) can be pre-stressed, being stretched or tensed during the joining process between strips. In the state of the art, profiles are made by roll-forming. By this technique, deep reinforcements are difficult to make due to the stresses and strains that are created around such reinforcing reinforcements. These stresses may modify in any cases the geometry of the profile.

[0071] According this invention, as different strips and different lengths of said strips are used, the reinforcing deformations can be made pronounced, without affecting, as they are in different strips, the geometry of the profile.

[0072] The different length between the strips allows reinforcing protrusions (14) to be made, in transversal and very pronounced form, to stiffen these strips:

• the central strip (7), for example, with continuous ribs on the pairs of opposites projections (9) of the crenellated longitudinal edges (4), and on the central longitudinal zone (29).
• The external strips (8), with reinforcing ribs to increase the apparent thickness and facilitate the screwing of prefabricated elements.

[0073] As indicated above, the union between the outer end (11) of the projections (9) and the stripe for longitudinal union (3) can be made by welding, clinching, riveting, clipping, bending, pressure and folding, etc.

[0074] As is shown in figures 26 y 27, the strips of the construction element (1) and the projections (9) of the crenellated longitudinal edges (4), may have reinforcing deformations (14,15), for example in the form of grooves.

[0075] Although in the shown examples, all the projections (9) belonging to the same strip have equal size, the projections (9) may have different sizes, in only one crenellated longitudinal edge (4) or in opposite crenellated longitudinal edges (4) of the same strip.

[0076] The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all aspects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Claims

1. Construction element in form of a profile (1), comprising at least two strips joined by at least a longitudinal union, characterized in that:

- at least one of said strips (6-7) has one or two crenellated longitudinal edges (4), with alternating projections (9) and recesses (10);

- each longitudinal union between strips is made between projections (9) of at least one crenellated longitudinal edge (4) of one strip (6-7) and at least one stripe for longitudinal union (3) belonging to other strip (6,7,8);

- the number of strips (6-7) having one or two crenellated longitudinal edges (4) is less than or equal to the number of strips (6,7,8) which have at least one stripe for longitudinal union (3).

2. Element according to claim 1, characterized in that the stripe or stripes for longitudinal union (3) of at least one of the strips (6,7,8) are located along the longitudinal central zone (29) of said strip.

3. Element according to claim 1, wherein the stripe or stripes for longitudinal union (3) of at least one of the strips (6,8) are close or limited by a non crenellated longitudinal edge (5).

4. Element according to claim 1, characterized in that the longitudinal union between strips is made between projections (9) of a crenellated longitudinal edge (4) of a first strip (6-7) and at least two stripes for longitudinal union (3), belonging to a second strip (6,7,8), separated transversely to each other.

5. Element according to claim 1, characterized in that the longitudinal union between strips is made between projections (9) of crenellated longitudinal edges (4) of a first strip with two crenellated longitudinal edges (7) and at least one stripe for longitudinal union (3), belonging to a second strip (6,7,8).

6. Element according to claim 4 or 5, characterized in that the projections (9), through which the longitudinal union between strips is made, have opposite transversal slopes

7. Element according to any of the preceding claims, characterized in that the strips (6,7,8) have reinforcing protrusions (14,15).

8. Element according to claim 1, characterized by comprising at least one strip having at least one non-crenellated longitudinal edge (5) finished as a toothed edge (28).

9. Element according to claim 1, wherein the strips (6,7,8) having at least one stripe for longitudinal union (3) are deformed in the form of reinforcing groove (15), coinciding said groove with said stripe for longitudinal union (3).

10. Element according to claim 1, characterized in that at least one strip (6,7) with at least one crenellated longitudinal edge (4) has all their projections (9) of equal size.

11. Element according to claim 1, characterized in that at least one strip (6,7) with at least one crenellated longitudinal edge (4) includes projections (9) of different sizes.

Drawing