TECHNICAL FIELD The present invention relates to horizontal formworks.

PRIOR ART Flexible or non-modular formworks in which the different parts forming the formwork do not have fixed positions and are assembled depending on the needs of the formwork are known. Such systems are very flexible but have low assembling and disassembling efficiencies. On the other hand, modular formworks in which the positions of the elements are fixed are known. Such systems offer high assembling and disassembling efficiencies and furthermore the assembling and disassembling processes are safer than in non- modular formworks. In contrast, such systems have the drawback that they are systems with reduced flexibility.

For example WO 02/084050 A1 discloses a modular horizontal formwork comprising a plurality of grids. Each grid comprises four heads arranged at the vertices of said grid, each head being supported by a respective prop. Each basic grid further comprises two main beams arranged parallel to one another, each end of said main beams being supported on one of the heads, and two edge beams arranged parallel to one another and perpendicular to the main beams, each end of said edge beams being supported on one of the heads. The main beams comprise supports for panels on which the formwork panels are arranged. ES 8700375 A1 discloses a modular horizontal formwork comprising a plurality of grids. Each grid comprises four heads arranged at the vertices of said grid, each head being supported by a respective prop. Each basic grid further comprises two main beams arranged parallel to one another, each end of said main beams being supported on one of the heads, and two edge beams arranged parallel to one another and perpendicular to the main beams, each end of said edge beams being supported on one of the heads. Each of the main beams comprises a housing at each longitudinal side. Each basic grid further comprises a central beam supported by the respective housings. FR 2136813 A5 discloses a modular horizontal formwork comprising a plurality of grids. Each grid comprises four heads arranged at the vertices of said grid, each head being supported by a respective prop. Each basic grid further comprises two main beams arranged parallel to one another, each end of said main beams being supported on one of the heads, and two edge beams arranged parallel to one another and perpendicular to the main beams, each end of said edge beams being supported on one of the heads. Each of the main beams comprises a longitudinal support surface at each longitudinal side, such that central beams can be supported on said support surfaces. JP S63206559 A discloses a modular horizontal formwork comprising a plurality of grids. Each grid comprises four heads arranged at the vertices of said grid, each head being supported by a respective prop. Each basic grid further comprises two main beams arranged parallel to one another, each end of said main beams being supported on one of the heads, and two edge beams arranged parallel to one another and perpendicular to the main beams, each end of said edge beams being supported on one of the heads. Each of the main beams comprises a longitudinal central part and a support surface on each longitudinal side of the central part. The support surfaces are disposed at a height lower than the central part such that central beams can be supported on either side of said central part.

DISCLOSURE OF THE INVENTION

The object of the invention is to provide a horizontal formwork, as defined in the claims. The horizontal formwork of the invention comprises a support base and a plurality of formwork panels which are supported on said support base. The support base comprises a plurality of basic grids. Each basic grid comprises four heads arranged at the vertices of said basic grid, each head being supported by a respective prop. Each basic grid further comprises two main beams arranged parallel to one another, each end of said main beams being supported on one of the heads, and two edge beams arranged parallel to one another and perpendicular to the main beams, each end of said edge beams being supported on one of the heads.

Each basic grid also comprises a plurality of central beams which are arranged parallel to the edge beams and supported on the main beams, the main beams comprising housings adapted for receiving an end of a respective central beam.

The formwork panels are supported on respective support surfaces of the edge beams and the central beams.

At least one basic grid comprises at least one main beam comprising a plurality of support sections for additional beams for supporting the formwork panels. Said support sections comprise a support surface for additional beams which is arranged below the formwork panels, allowing, if necessary, additional beams to be supported on said support surface projecting on both sides of the main beam, extending the support base by means of the portion of said additional beams projecting out of the basic grid.

As the additional beams project on both sides of the main beam, same sized additional beams can be used to extend the support base adapting it to different areas. In order to do so, the portion of the additional beams that is necessary to cover the specific area is projected out of the basic grid, while the remaining portion projects towards the inside of the basic grid. This is not possible in the horizontal formworks of the prior art, because the main beams of said formworks can only support beams on one longitudinal side or the other. Therefore, as a result of this configuration of the main beam, a modular system with flexibility for extending its support base longitudinally is provided, thereby being able to cover a remaining space in which an additional basic grid does not fit. The horizontal formwork of the invention is therefore a hybrid system combining the advantages of modular formworks with the advantage of longitudinal flexibility which is obtained with flexible formworks.

These and other advantages and features of the invention will become evident in view of the drawings and the detailed description of the invention.

DESCRIPTION OF THE DRAWINGS

Figure 1 shows a perspective view of the horizontal formwork according to a first embodiment of the invention, wherein the support base comprises, in addition to a plurality of basic grids and a plurality of edge grids, extensions of the support base both in the longitudinal direction and the transverse direction.

Figure 2 shows a perspective view of a basic grid of the horizontal formwork shown in Figure 1.

Figure 3 shows a perspective view of a basic grid of the horizontal formwork shown in Figure 1 with a formwork panel arranged on said basic grid.

Figure 4 shows a perspective view of a basic grid of the horizontal formwork shown in Figure 1 with an extension of the support base in the longitudinal direction.

Figure 5 shows a perspective view of an edge grid of the horizontal formwork shown in Figure 1 with an extension of the support base in the transverse direction. Figure 6 shows a perspective view of a head of the basic grid shown in Figure 2.

Figure 7 shows another perspective view of the head of the basic grid shown in Figure 2. Figure 8 shows a perspective view of a main beam of the basic grid shown in Figure 2.

Figure 9 shows a perspective view of an edge beam of the basic grid shown in Figure 2.

Figure 10 shows a perspective view of a central beam of the basic grid shown in Figure 2.

Figure 1 1 shows a perspective view of an additional beam of the basic grid shown in Figure 2.

Figure 12 shows a perspective view of a modified edge beam of the edge grid shown in Figure 5. Figure 13 shows a perspective view of a filler of the basic grid shown in Figure 3.

Figure 14 shows a perspective view of an embodiment of a grid for bypassing a pillar. Figure 15 shows a perspective view of the horizontal formwork according to a second embodiment of the invention, wherein the support base comprises, in addition to a basic grid, a plurality of cantilever grids.

Figure 16 shows a perspective view of a perimetral head of the cantilever grids shown in Figure 15.

Figure 17 shows a perspective view of the horizontal formwork according to a third embodiment of the invention, wherein the support base comprises, in addition to a plurality of basic grids, a plurality of grids for a hanging beam.

Figure 18 shows a perspective view of a grid for a hanging beam of the horizontal formwork shown in Figure 17.

Figure 19 shows a perspective view of a grid for a hanging beam with a formwork panel and two stop ends arranged on said grid. Figure 20 shows a perspective view of a hanging beam support of a grid for a hanging beam shown in Figure 18.

DETAILED DISCLOSURE OF THE INVENTION

A horizontal formwork 1 according to the invention comprises a support base and a plurality of formwork panels 17 which are supported on said support base. The support base comprises a plurality of basic grids 10.

The basic grids 10 form a modular formwork. Furthermore, the horizontal formwork 1 according to the invention can comprise extensions of the support base both in the longitudinal direction and the transverse direction adapting said support base to wall finishings, as shown, for example, in the embodiment of Figure 1 .

To understand this description, longitudinal direction will be considered the direction perpendicular to the main beams 3, i.e., the direction indicated with an "x" in Figure 1 , whereas transverse direction will be considered the direction parallel to the main beams 3, i.e., the direction indicated with a "y" in Figure 1 .

A horizontal formwork 1 according to the invention can also comprise grids that are adapted to pillars, cantilever elements and hanging beams. The horizontal formwork 1 of the invention therefore offers the advantages of a modular formwork since a large part of the assembly is performed with basic grids 10, but at the same time offers a great adaptability since said basic grids 10 can be extended and/or combined with adaptable grids that are adapted to the support based on the previously indicated cases.

Figures 2 and 3 show an embodiment of a basic grid 10 according to the invention.

A basic grid 10 comprises four heads 2 arranged at the vertices of said basic grid 10, each head 2 being supported by a respective prop 18. The basic grid 10 also comprises two main beams 3 arranged parallel to one another, each end of said main beams 3 being supported on one of the heads 2, and two edge beams 4 arranged parallel to one another and perpendicular to the main beams 3, each end of said edge beams 4 being supported on one of the heads 2. Therefore, the main beams 3 and edge beams and 4 form the perimeter of the basic grid 10, the heads 2 being arranged at the vertices of the grid.

The basic grid 10 also comprises a plurality of central beams 5, three in the embodiment shown in Figures 2 and 3, which are arranged parallel to the edge beams 4. Said central beams 5 are supported on the main beams 3, to that end, the main beams 3 comprise housings 30 adapted for receiving an end of a respective central beam 5.

The formwork panels 17 arranged on the basic grids 10 are supported on respective support surfaces 40, 50 of the edge beams 4 and the central beams 5.

At least one basic grid 10 of the support base comprises at least one main beam 3 comprising a plurality of support sections 31 for additional beams 6 for supporting the formwork panels 17. Said support sections 31 comprise a support surface 32 for additional beams 6 which is arranged below the formwork panels 17, allowing the additional beams 6 that are supported on said support surface 32 to project on both sides of the main beam 3, extending the support base by means of the portion of said additional beams 6 projecting out of the basic grid 10, as shown in Figure 4. Therefore, additional beams 6 can be overlapped on the support surfaces 32 of these main beams 3 since a gap 35 is created between the support surface 32 and the formwork panel 17 which allows arranging an additional beam 6 in said gap 35. Said gap is preferably 80m m since the standard wood beams usually available in construction works tend to have that width and such standard beams can therefore be used as additional beams for extending the support base.

In the embodiments shown in the drawings, all the main beams 3 of the basic grids 10 are the same, i.e., all of them comprise support sections 31 in addition to the housings 30. This gives the invention the additional advantage of minimizing the number of different type of parts to be used in the formwork. Modular formworks are easier to assemble and disassemble than flexible formworks, since the positions of the components are fixed. However, modular formworks have the drawback that they are not flexible when they come into contact with finishings, pillars, etc., and therefore there is usually a need to combine same with other formwork systems in said areas. The horizontal formwork 1 of the invention is a hybrid system combining the advantages of modular formworks with the advantage of the longitudinal flexibility which is obtained with flexible formworks. Said horizontal formwork 1 is modular because it is formed by basic grids 10, the positions of the components of each basic grid 10 being fixed, including the positions of the central beams 5, since they are supported on the housings 30 of the main beams 3. Furthermore, the support sections 31 of the main beams 3 provide the basic grid 10 with the possibility of overlapping additional beams 6 for extending the support base in said longitudinal direction, enabling the horizontal formwork 1 to be adapted for wall finishings, for example.

Figure 8 shows in detail a main beam 3 of this embodiment. The main beams 3 comprise an intermediate portion 3b and two ends 3a, the housings 30 and the support sections 31 being in the intermediate portion 3b, the intermediate portion 3b being arranged at a height lower than the ends 3a.

In this embodiment, the intermediate portion 3b of said main beams 3 comprises a support surface, the housings 30 being arranged on said support surface and the remaining of said support surface forming the support surfaces 32 of the support sections 31 .

In this embodiment, the housings 30 of the main beams 3 are arranged equidistant from one another, the support sections 31 being arranged after said housings 30. The main beam 3 comprises housings 30 at each longitudinal side, since a main beam 3 can be shared by two adjacent basic grids, as shown in the embodiment shown in Figure 1 . The main beam 3 of this embodiment comprises six housings 30, three for each adjacent basic grid 10.

In this embodiment, each housing 30 of the main beams 3 comprises a rectangular base and two side walls 30b extending perpendicularly from the ends of said base, forming a U-shaped housing 30. Each housing 30 of the main beams 3 further comprises a coupling flange 33 extending perpendicularly from the base. Furthermore, in this embodiment the central beams 5 comprise a coupling window 51 in the proximity of each of the ends thereof such that the central beams 5 are coupled to the respective main beam 3 housing the coupling flange 33 of the main beam 3 in the respective coupling window 51 of the central beam 5.

In this embodiment, the main beam 3 comprises a plurality of projections 34 in its lower portion through which they are coupled to respective props 18 and which together with the props 18 which are coupled to the heads 2 support the weight of the basic grids 10.

The head 2, shown in detail in Figures 6 and 7, comprises in this embodiment four housings 20 which are arranged orthogonal to one another and are adapted for receiving the end of a main beam 3 or the end of an edge beam 4. In fact, in this embodiment the four housings 20 of the head 2 are arranged at the same height and are adapted for receiving interchangeably the end of a main beam 3 or the end of an edge beam 4. In this embodiment, each housing 20 of the head 2 comprises a rectangular base 20a and two side walls 20b extending perpendicularly from the ends of said base 20a, forming a U-shaped housing 20. Each housing 20 of the head 2 further comprises a coupling flange 21 extending perpendicularly from the base 20a. Both the main beams 3 and the edge beams 4 of this embodiment comprise in each of their ends a coupling window such that said main beams 3 and edge beams and 4 are coupled to the respective head 2 housing the coupling flange 21 of the head 2 in the respective coupling window. In this embodiment, the head 2 is a drophead. Therefore, the head 2 comprises a fixed portion and a moving portion. The fixed portion comprises a central rod 22 and an abutment surface 23. The moving portion comprises a part comprising the four housings 20 of the head and a rotating wedge 24. The central rod 22 comprises two flat bars 25 which are arranged longitudinally on a portion of said central rod 22. The rotating wedge 24 comprises a housing copying the outer shape of the central rod 22 together with the flat bars 25. Depending on the radial position of the rotating wedge 24, when the central rod 22 and the flat bars 25 fit into the hole of the rotating wedge 24, the rotating wedge 24 will move down in a guided manner to the abutment surface 23 and along with the rotating wedge 24, the part with the housings 20. This type of drophead aids in disassembling the grid.

In this embodiment, the edge beam 4, shown in detail in Figure 9, comprises at each longitudinal side the previously described support surface 40 on which the formwork panels 17 are supported, and an abutment wall 41 , said support surface 40 and said abutment wall 41 forming a bracket at each longitudinal side of the edge beam 4. Said bracket is adapted for receiving the end of a formwork panel 17, such that the opposing brackets of the two edge beams 4 forming a basic grid 10 form a track for the formwork panels 17. In this first embodiment, the length of the formwork panels 17 arranged on the basic grids 10 coincides with the distance between the opposing brackets of the two edge beams 4 forming a basic grid 10. Therefore, the formwork panels 17 are guided in the tracks and can only move in the longitudinal direction. A horizontal formwork which is safer for the operators is thereby achieved.

In this embodiment, the abutment walls 41 of the edge beams 4 form a housing 42 adapted for receiving a filler 43, such that said filler 43 can seal the gap formed between two adjacent formwork panels 17 in the longitudinal direction. The ends of the fillers 43 are supported on the fixed portions of the respective heads 2. The fillers 43 of two adjacent basic grids 10 are arranged in contact in the longitudinal direction such that they form a continuous surface once assembled.

A good finish is obtained with the horizontal formwork of the invention. On one hand, the formwork panels 17 are arranged in contact with one another in the longitudinal direction and on the other hand, the fillers 43 fill the gap between the formwork panels 17 in the transverse direction, achieving a continuous surface. It is suitable for the filler 43 to project as little as possible with respect to the formwork panels 17 so that the finish is good.

The manner in which the partial disassembly of a basic grid 10 according to this embodiment is performed is described below:

- The props 18 coupled to the main beams 3 are first removed. The heads 2 are then released from the wedge by rotating the rotating wedge 24. Therefore, the moving portions of the heads 2 move down and therefore the housings 20 of the heads 2 move down and together with said housings 20 the main beams 3, the edge beams 4, the central beams 5 and the formwork panels 17 move down. The fixed portions of the heads 2 do not move and therefore support the weight of the slab.

The edge beams 4 are then removed.

The central beams 5 and the formwork panels 17 are then removed.

Finally, the main beams 3 are removed.

The slab will be supported by the props 18 supporting the heads 2. Since the ends of the fillers 43 are supported on the fixed portions of the heads 2, said fillers 43 will also be assembled until the complete disassembly in which they are removed together with the heads 2 and the respective props 18 thereof. Therefore, almost all the elements of the basic grids 10 can be removed once the slab acquires enough strength. The rest of the elements will be removed when the slab is completely dry.

The embodiment shown in Figure 1 shows a horizontal formwork 1 with wall finishings both in the longitudinal direction and the transverse direction. When a horizontal formwork 1 is carried out in a space in which vertical walls have already been made, the horizontal formwork 1 must be adjusted to said vertical walls. As mentioned above, the horizontal formwork 1 of the invention is mainly carried out with basic grids 10 forming a modular formwork. What happens is that when the modular formwork is moved close to a wall, a space may remain between the basic grid 10 closest to the wall and the wall is insufficient for another basic grid 10 to fit in. The horizontal formwork 1 of the invention allows extending the support base up to the wall in a simple manner.

Figure 4 shows in detail a wall finishing in the longitudinal direction. To carry out a wall finishing in the longitudinal direction, i.e., to adjust the support base to the wall in the longitudinal direction, the horizontal formwork 1 comprises a plurality of additional beams 6, each additional beam 6 being supported on a support surface 32 of a main beam 3 of a basic grid 10 and on a second support surface 32' external to the plurality of basic grids 10, said additional beams 6 extending the support base formed by said basic grid 10 longitudinally. The formwork panels 17 which are arranged on the extension of the support base are supported on the support surfaces 60 of the additional beams 6. The additional beams 6 are preferably arranged perpendicular to said main beam 3. The horizontal formwork 1 of the invention allows to carry out wall finishings in the longitudinal direction with same sized additional beams 6, regardless of the space between the basic grid 10 closest to the wall and the wall. The additional beams 6 cannot project from the portion of the wall, so to enable carrying out finishings in spaces of different size with one and the same additional beam 6, the additional beam 6 must be able to project from the main beam 3 towards the inside of the basic grid 10 closest to the wall. This overlapping of the additional beam 6 with the main beam 3 allows the extension of the support base for covering the distance between the basic grid 10 closest to the wall and the wall. In the embodiment shown in Figure 4, the second support surface 32' of the additional beams 6 is a support surface 32' of an additional support beam 3' supported by props 18. In this embodiment, the additional support beam 3' is the same as the main beam 3 on which the additional beams 6 are supported and the ends of said additional support beam 3' are supported on respective heads 2' which are the same as the heads 2 of the basic grids 10.

In this embodiment, the additional beam 6 shown in detail in Figure 1 1 comprises a plurality of grooves 62 in its lower portion adapted for fitting in the support sections 31 of the main beam 3 and in the additional support beam 3'. The additional beam 6 also comprises a continuous support section 63 which could be arranged on said support sections of the main beam 3 and on the additional support beam 3'.

The additional beams 6 of this embodiment comprise a nailing block 61 , preferably made of plastic although it could also be made of wood. The nailing block 61 allows nailing the formwork panel 17 arranged on said additional beam 6 and the additional beam 6 itself. This operation may be necessary for safety reasons in certain spaces of the horizontal formwork.

In other possible embodiments, another type of additional beams, for example, standard wood beams that are usually available in all construction works can be used.

In other embodiments, the additional support beams could be different from the main beams as long as the additional beams can be supported on said additional support beam and the end of the additional beam supported on said additional support beam is flush with the end of the additional beam supported on the main beam of the basic grid. Furthermore, in other embodiments another type of heads could be used as long as the heads on which the additional support beam is supported have two housings arranged at 180°, for example.

In this embodiment, the main beams 3 are used as additional support beam 3' and the heads 2' are the same as the heads 2 of the basic grids 10, for reducing the number of different type of parts to be used for assembling the base support of the horizontal formwork 1 .

In this embodiment, the main beam 3 and the additional support beam 3' are arranged parallel to one another but in other embodiments in which the wall has an inclination with respect to the main beam 3, the additional support beam 3' can be arranged parallel to the wall and therefore inclined with respect to the main beam 3.

Figure 5 shows in detail a wall finishing in the transverse direction. To carry out a wall finishing in the transverse direction, the support base comprises a plurality of edge grids 1 1 which are arranged contiguous to the basic grids and in the transverse direction at the end closest to the wall. The edge grids 1 1 differ from the basic grids 10 in that at least one edge beam 4, specifically the edge beam which is arranged closest to the wall, is replaced with a modified edge beam 4'.

The modified edge beam 4' of this embodiment shown in detail in Figure 12 comprises a support surface 40' for additional beams 6 for supporting the formwork panels 17. Said support surface 40' is arranged below the formwork panels 17, allowing said additional beams 6 to be supported on said support surface 40' projecting on both sides of the modified edge beam 4', extending the support base by means of the portion projecting out of the edge grid 1 1 . The formwork panels 17 which are arranged on the extension of the support base are supported on the support surfaces 60 of the additional beams 6. To carry out the wall finishing in the transverse direction, the support base therefore comprises a plurality of additional beams 6, each additional beam 6 being arranged supported on a support surface 40' of a modified edge beam 4' and on a second support surface 40" external to the plurality of grids 10 and 1 1 , said additional beams 6 extending the support base formed by said grids 10 and 1 1 transversely. In this embodiment, the additional beams 6 are the same as those used in the wall finishing in the longitudinal direction, minimizing the number of different type of parts to be used in the horizontal formwork 1 .

In the embodiment shown in Figure 5, the second support surface of the additional beams 6 is a support surface 40" of an additional support beam 4" supported by props 18. In this embodiment, the additional support beam 4" is the same as the modified edge beam 4' on which the additional beams 6 are supported. Furthermore, the ends of said additional support beam 4" are supported on respective heads 2' which are the same as the heads 2 of the basic grids 10.

The horizontal formwork 1 of the invention, in addition to carrying out finishings on walls, allows carrying out springings on wall. If a basic grid 10 is arranged against a wall which is arranged parallel to the main beams 3 there is no problem since the formwork panel 17 can be supported on said basic grid 10 and against the wall. However, if a basic grid 10 is arranged against a wall parallel to the edge beams 4, there would be a gap between the edge beam 4 and said wall that must be covered with additional formwork panels. To that end, when a formwork is started adjacent to a wall parallel to the edge beams 4, springing grids adjacent to said wall are arranged. The springing grids differ from the basic grids 10 in that the heads closest to the wall are replaced with springing heads which are arranged below the main beams 3 and in that the edge beam 4 closest to the wall is dispensed with, only the other one being maintained. Therefore, the end of the main beams 3 closest to the wall being stuck to the wall, creating a lane for the formwork panels 17 between the wall and the edge beam 4 of said springing grid in which the formwork panels 17 fit. The springing head comprises a U-shaped housing for being coupled to the respective main beam 3 and two housings at 180° adapted for receiving the end of a central beam 5. A central beam 5 is supported on said housings of the springing head to give support to the formwork panels 17. The springing heads are shored up by means of a respective prop.

As mentioned above, in addition to finishing on walls, the horizontal formwork of the invention allows carrying out grids for bypassing pillars.

Figure 14 shows in detail an embodiment of a grid for bypassing a pillar 12. Such grids are arranged between basic grids 10. The grid for bypassing a pillar 12 differs from the basic grids 10 in that, for bypassing a pillar arranged within said grid 12, at least two central beams 5 between which the pillar is arranged, are replaced with modified central beams 5'. The modified central beams 5' comprise respective support surfaces 50' on which additional beams 6 are supported. Therefore, the formwork panels 17 which are arranged on the grid for bypassing a pillar 12 are supported on the respective support surfaces 60, 40 of the additional beams 6 and the edge beams 4 of said grid 12. The additional beams 6 are arranged on both sides of the pillar. In this embodiment, the modified central beams 5' are shored up by means of a respective prop 18. In this embodiment, the central beam 5 that would be arranged flush with the pillar is omitted. In other embodiments in which the pillar is arranged between two central beams 5, it would not be necessary to omit any central beam 5. In other embodiments, depending on the width of the pillar, it may be necessary omit more than one central beam 5.

In this embodiment, the modified central beams 5' are the same as the modified edge beams 4' used in the edge grids 1 1 . Furthermore, the additional beams 6 also are the same as those used in the extensions of the support base. Therefore, no special elements are needed for carrying out such grids.

Figure 15 shows an embodiment of a horizontal formwork 1 in which the support base comprises, in addition to a basic grid 10, a plurality of cantilever grids 13, 14 and 15. The cantilever grids 13, 14 and 15 are those in which a portion of the grid projects with respect to the slab in the which the support base is arranged.

A transverse cantilever grid 13 differs from the basic grids 10 in that the edge beam 4 arranged in a cantilever manner is replaced with a modified cantilever edge beam 4"'. Furthermore, the heads on which said modified cantilever edge beam 4"' is supported are perimetral heads 7 which are supported by a respective inclined prop 18. In this embodiment, the modified cantilever edge beam 4"' is the same as the central beams 5 of the basic grids 10.

The perimetral head 7 of this embodiment comprises a central housing 70 with secure fixing system comprising a pin and a fork. The perimetral head 7 of this embodiment further comprises two corner housings 71 , arranged orthogonal with respect to the central housing 70, and having the same characteristics as the housings 20 of the heads 2 of the basic grids 10. The perimetral head 7 also comprises a handrail housing 72 adapted for receiving the support of a handrail and a projection 73 in which a respective inclined prop 18 can be coupled.

In this embodiment, the ends of the main beams 3 are supported on the central housing 70 of the respective perimetral head 7, whereas the ends of the cantilever edge beam 4"' are supported on the corner housings 71 of the perimetral head 7.

To increased safety and to prevent the grid from being able to tilt, the main beams 3 of the cantilever grid 13 are fixed to the heads 2 by means of a respective fixing element. The side walls of the housings 20 of the head 2 comprise a fixing hole 26, whereas the main beams 3 comprise fixing holes 36 at the ends 3a thereof. The fixing holes 36 of the main beam 3 are flush with the fixing holes 26 of the housings 20 of the head 2 when the main beam 3 is coupled to the respective head 2 housing the coupling flange 21 of the head 2 in the respective coupling window. The fixing element goes through said fixing holes 26 and 36, providing a safe, anti-tilt fixing. In this embodiment, the assembly of this transverse cantilever grid 13 after a pre- assembled basic grid 10 is performed in the following manner:

- The main beams 3 are first hanged on the heads 2 of the adjacent basic grid 10.

- A perimetral head 7 is then fixed at the opposite end of said main beams 3.

- A modified cantilever edge beam 4"' is then coupled between the perimetral heads 7.

- The assembly is then hoisted and shored up by means of props 18 which are coupled to the main beams 3 and to the perimetral heads 7.

- A plurality of central beams 5 are then arranged supported on the main beams 3. To that end, in this embodiment the ends of the central beams 5 are housed in housings 30 of the main beams 3. - Finally, the attachment of the main beams 3 with the heads 2 is securely fixed by means of fixing elements.

A longitudinal cantilever grid 14 differs from the basic grids 10 in that the heads on which the main beam 3 arranged in a cantilever manner is supported are perimetral heads 7 supported by a respective inclined prop 18.

Said cantilever grid 14 further comprises an additional main beam 3" which is arranged flush in the transverse direction with the slab on which the horizontal formwork 1 is arranged and which is fixed to an edge beam 4 with an inner head. The additional main beam 3" is supported by a plurality of props 18. In this embodiment, the additional main beam 3" is the same as the main beam 3 of the basic grids 10. The central beams 5 of the grid 14 are also supported on said additional main beam 3" specifically on the support blocks 38.

The inner head of this embodiment comprises two housings arranged at 180°, each of them being adapted for receiving the end of an additional main beam 3'. The inner head of this embodiment comprises a U-shaped housing for coupling the inner head to the edge beam. The head also comprises a projection adapted for being coupled to a respective prop.

For increased safety, the edge beams 4 of the cantilever grid 14 are fixed to the heads 2 by means of a respective fixing element. In this embodiment, the perimetral heads 7 and the fixing elements are the same as those used in the transverse cantilever grid 13.

In this embodiment, the assembly of this longitudinal cantilever grid 14 after a pre- assembled basic grid 10 is performed in the following manner:

- The edge beams 4 are first hanged on the heads 2 of the adjacent basic grid 10.

- A perimetral head 7 is then fixed at the opposite end of said edge beams 4.

- A main beam 3 is then coupled between the perimetral heads 7.

- The assembly is then hoisted and shored up by means of inclined props 18 which are coupled to the perimetral heads 7.

- A plurality of central beams 5 are then arranged supported on the main beams 3 and the attachment of the edge beams 4 with the heads 2 is securely fixed by means of fixing elements. In this embodiment, specifically the ends of the central beams 5 are housed in housings 30 of the main beams 3.

- Finally, an additional main beam 3" is arranged flush with the end of the slab on which the horizontal formwork 1 is arranged and is fixed to an edge beam 4 with an inner head which is shored up to the slab with a respective prop. A pair of additional props 18 are arranged for shoring up the additional main beam 3"

A cantilever vertex grid 15 is arranged between a transverse cantilever grid 13 and a longitudinal cantilever grid 14, in a cantilever vertex of the support base. The cantilever vertex grid 15 comprises a main beam 3 arranged flush in the transverse direction with the slab on which the horizontal formwork 1 is arranged and is fixed to the edge beam 4 which it shares with the longitudinal cantilever grid 14 by means of the inner head. Said main beam 3 is supported by means of a plurality of props 18.

The cantilever vertex grid 15 further comprises a plurality of additional beams 6 that are supported on the main beam 3 which it shares with the transverse cantilever grid 13 and on the main beam 3 arranged flush in the transverse direction with the slab. Therefore, the formwork panels are supported on support surfaces 60 of the intermediate beams 6.

For increased safety, the additional beams 6 are fixed to the main beam 3 that the cantilever vertex grid 15 shares with the transverse cantilever grid 13 by means of a respective fixing element.

In this embodiment, the assembly of this cantilever vertex grid 15 is performed in the following manner:

- A main beam 3 is arranged flush in the transverse direction with the slab on which the horizontal formwork 1 is arranged and is coupled to the edge beam 4 which it shares with the longitudinal cantilever grid 14 by means of the inner head which is shored up to the slab with a respective prop 18.

- Said main beam 3 is shored up by means of a plurality of props 18.

- A plurality of additional beams 6 are then arranged supported on the main beam 3 which it shares with the transverse cantilever grid 13 and on the main beam 3 arranged flush in the transverse direction with the slab. - Finally, the additional beams 6 are fixed to the housings of the main beam 3 which it shares with the transverse cantilever grid 13 by means of a respective fixing element.

Figure 17 shows an embodiment of the support base comprising a plurality of grids for hanging beams 16 and Figure 18 shows in detail one of said grids for hanging beams 16. Such grids are arranged between basic grids 10.

A grid for a hanging beam 18 comprises two hanging beam supports 9 which are arranged parallel to one another. A hanging beam support 9, shown in detail in Figure 20, comprises a base 90 and a support 91 which is arranged at each end of said base 90. Each support 91 comprises a coupling element 92 and a telescopic shaft 93. The coupling element 92 is adapted for being supported both on the housing 20 of a head 2 of an adjacent basic grid 10, as shown in Figure 17, and on a support surface 32 of a main beam 3 of the adjacent basic grid 10 or on a support surface 40' of a modified edge beam 4' of an adjacent edge grid 1 1. The telescopic shaft 93 of the support 91 has one of its ends fixed to an end of the base 90 and the other end fixed to the coupling element 92, and since it is telescopic, the distance between the two ends thereof can vary such that it allows carrying out hanging beams at different heights depending on the positioning of said telescopic shaft 93. The base 90 comprises a plurality of holes 95 in which a head with housings 96 can be fixed. In this embodiment, each head comprises two housings adapted for receiving the end of a respective main beam 3 and a U-shaped housing that fits in the base 90. In other embodiments, the base could have the housings incorporated therein. The base 90 of the hanging beam support 9 comprises a projection adapted for being coupled to a prop 18.

A grid for a hanging beam 16 also comprises at least two main beams 3 arranged parallel to one another and perpendicular with respect to the bases 90 of the hanging beam supports 9, the ends of the main beams 3 being housed in respective housings 96 of the hanging beam support 9. The main beams 3 are supported by a plurality of props 18. The main beams 3 of this embodiment are the same as the main beams 3 of the basic grids 10 so it is not considered necessary to describe them again.

A grid for a hanging beam 16 also comprises a plurality of additional beams 6 which are supported on the main beams 3.

To carry out a hanging beam, in addition to arranging at least one formwork panel 17 on the support surfaces 60 of the additional beams 6, at least two stop ends 97 are arranged on said at least one panel formwork 17. The stop ends 97 are arranged parallel to one another and perpendicular with respect to the formwork panel 17 on which they are arranged. In this embodiment, brackets are used to fix the stop ends 97 to the corresponding formwork panel 17.

The stop ends 97 together with the formwork panel 17 demarcate the space for creating the hanging beams.