The subject of the invention is a padded formwork, at least one form lining of which is covered with a flexible pad. The invention can be used in formworking for creating stone walls, columns, arches and other profiles.

Cast walls, vaults, arches and domes are known already from the ancient Rome. One of the best known examples of these is the dome of the Pantheon in Rome, casted from concrete. It was built around 126-128 BC. For casting concrete profiles, formworks are used. A means for casting stone walls is, however, still unknown.

Several types of formworks are known. Different types of wall formworks are presented in the course manual Wall formwork systems (original title: Falzsaluzati rendszerek) from Mora Ibolya Eva. The majority of the formworks comprise form linings and frames supporting the form linings. The shape of the finished product is defined by the shape of the form lining. The use of planar form linings is the most widespread and most simple. For creating arches, arched form linings are used. Free-form formworks are also known, the form linings of which are of free form. A free-form formwork is revealed in the patent document with Publication Number EP3501769A1, which presents a method of creating a free form form lining by 3D printing.

The inner surfaces of the known formworks are rigid. Stones are not showing or only very small parts of them are showing from the concrete poured in the known formworks, because the stones touch the inner side of the formwork only on very small surfaces and other surfaces of the stones are flowed around by the binder. The essential of the stone wall is the visible joint (binder), which is clearly and particularly distinct from the stones creating the wall. In stone walls, those surfaces of the stones which look outward are not covered with binder, while the space between the stones are filled with binder. Stone walls cannot be created with the known formworks. The invention aims at proposing a formwork for casting profiles, which have visible stone surfaces and which are made of binder and of stones of at least 40 mm in diameter and which profiles are characterised in that after curing of the binder and removing of the formwork, the stones are showing without being cleaned from the binder in a separate step, or without the binder in the joints requiring separate finishing process or other treatment.

The rationale behind the invention is the recognition that if the form lining is covered with flexible pad, the objectives above are completely realized.

The invention is therefore a padded formwork, which comprises at least one form lining, characterised in that the form lining is covered with a flexible pad.

A preferred embodiment of the padded formwork in accordance with the invention is characterised in that the flexible pad is a sponge.

Another preferred embodiment of the padded formwork in accordance with the invention is characterised in that the flexible pad is an airtight rubber pad equipped with a valve.

A third preferred embodiment of the padded formwork in accordance with the invention is characterised in that the flexible pad is a rubber sheet of a shape fitting the form lining, the edges of the rubber sheet are fixed to the form lining airtightly; the form lining is made of airtight material; there is a valve on the form lining at its part covered with the rubber sheet.

The third preferred embodiment is preferably characterised in that the edges of the rubber sheet are fixed to the form lining by a clamping frame fixed to the form lining with bolts.

Any of the above mentioned preferred embodiments can be preferably supplemented with the characteristic that the padded formwork is a double sided wall formwork with formwork panels facing each other, each of them comprising a form lining and a stiffening panel frame supported by braces. Any of the above mentioned preferred embodiments can be preferably supplemented with the characteristic that the padded formwork is equipped with at least one filler pipe, the length of which is larger than the height of the form lining and at one end of which there is an external thread.

Some preferred embodiments of the invention are presented below with the aid of drawings, wherein

Figure 1 is the vertical section of the formwork padded with a sponge,

Figure 2 is the vertical section of the formwork padded with an airtight rubber pad,

Figure 3 is the front view of the airtight fixing of the rubber sheet,

Figure 4 is the section view of the airtight fixing of the rubber sheet,

Figure 5 is the vertical section of the padded formwork equipped with a filler pipe, after loading the stones,

Figure 6 is the vertical section of the padded formwork equipped with a filler pipe, after inflating the rubber pad,

Figure 7 is the vertical section of the formwork padded with a sponge, after loading the stones,

Figure 8 is the vertical section of the formwork padded with a sponge, after pouring the binder,

Figure 9 is the vertical section of the formwork padded with an airtight rubber pad, after loading the stones,

Figure 10 is the vertical section of the formwork padded with an airtight rubber pad, after inflating the airtight rubber pad,

Figure 11 is the vertical section of the formwork padded with an airtight rubber pad, after pouring the binder, Figure 12 is the vertical section of the formwork padded with an airtight rubber pad, the formwork stripped after the curing time.

Figures 1, 7 and 8 show the arrangement of the sponges 3 as pads 1, of the form linings 2, of the panel frames 8, of the formwork panels 7 and of the braces 9 in a preferred embodiment of the padded formwork in accordance with the invention.

Figures 2, 9, 10, 11 and 12 show the arrangement of the airtight rubber pads 4 as pads 1, of the valves 5, of the form linings 2, of the panel frames 8, of the formwork panels 7 and of the braces 9 in a preferred embodiment of the padded formwork in accordance with the invention.

Figures 5 and 6 show the arrangement of the filler pipe 10, of the external thread 11, of the airtight rubber pads 4 as pads 1, of the valves 5, of the form linings 2, of the panel frames 8, of the formwork panels 7 and of the braces 9 in a preferred embodiment of the padded formwork in accordance with the invention.

Figures 3 and 4 show the arrangement of the form lining 2, of the valve 5, of the rubber sheet 12 as pad 1, of the bolts 13 and of the clamping frame 14 in a preferred embodiment of the padded formwork in accordance with the invention.

The preferred embodiment shown in Figure 1 is characterised in that the padded formwork is a double sided wall formwork with formwork panels 7 facing each other. The formwork panels 7 comprise a panel frame 8 and a form lining 2 fixed to the panel frame 8. Each panel frame 8 is supported with one brace 9 on its outer side opposite the form lining 2. These above are characteristic also to the preferred embodiments shown in Figures 2 and 5 to 12. The specific characteristic of the preferred embodiment shown in Figure 1 is that each of those sides of the form linings 2 which are facing each other is covered with a sponge 3 functioning as the pad 1. Two phases of the use of the preferred embodiment shown in Figure 1 are presented in Figures 7 and 8. The padded formwork shall be built first (i.e. formwork shall be erected), as shown in Figure 1, then the padded formwork shall be loaded with stones of at least 40 mm in diameter, as shown in Figure 7. After that, the spaces between the stones shall be filled with a binder, as shown in Figure 8. The sponge 3 prevents the sides of the stones toward the form lining 2 from being covered with the binder. After the curing time, the formwork panels 7 shall be removed (i.e. formwork shall be stripped).

The preferred embodiment shown in Figure 2 is different from the previous preferred embodiment in that the pads 1 are airtight rubber pads 4 with valves 5 on their tops. The shape of the airtight rubber pads 4 fits the form lining 2 when the airtight rubber pads 4 are deflated, which means that they are flat in this case. The use of this embodiment is shown by series of drawings in Figures 2, 9, 10, 11 and 12. Figure 2 shows the state after erecting the formwork, when the deflated or vacuumed airtight rubber pads 4 are fitted to the form linings 2 and the panel frames 8 are supported by the braces 9. Figure 9 shows the state after loading the stones and Figure 10 shows the state after inflating the airtight rubber pads 4. Figure 10 shows that the inflated airtight rubber pads 4 protrude among the stones and cover the stones on their surfaces toward the form lining 2. Figure 11 shows the next step, when the binder is poured between the stones. After that, when the binder is cured, the surrounded profile is stripped, i.e. the formwork panels 7 are removed, as shown in Figure 12.

Figure 4 presents a section view along line A-A shown in Figure 3. As shown in Figures 3 and 4, a further preferred embodiment of the padded formwork in accordance with the invention is different from the previous one in that the pad

1 is a rubber sheet 12, the edges of which are clamped airtightly to the form lining

2 by a clamping frame 14, which is fixed to the form lining 2 by fixing bolts 13. In the state shown in Figure 4, the space between the rubber sheet 12 and the form lining 2 has an excess pressure, the rubber sheet bulges therefore. These Figures do not show the panel frame 8, but it is evident for professionals how to construct a panel frame 8, because several examples are known among the prefabricated formwork systems.

As shown in Figure 5, a further preferred embodiment of the padded formwork in accordance with the invention is different from the preferred embodiment shown in Figure 2 in that the padded formwork is also equipped with a filler pipe 10, the length of which is larger than the height of the form lining 2 and there is an external thread 11 at its top end. It is worth using a plurality of filler pipes for padded formworks with considerable size. The filler pipe 10 is worth using in case of binders of large viscosity: the one end of the filler pipe 10 with the external thread 11 shall be placed above the level of the form lining 2 or of the form linings 2 , the other end of the filler pipe 10 shall be placed lower than the half of the height of the bottom stones. The filler pipe 10 shall be surrounded by stones, as shown in Figure 5, then the airtight rubber pads 4 shall be inflated through their valves 5. The following steps are similar for those shown in Figures 11 and 12. The filler pipe 10 is left between the stones and the binder, its end sticking out upwards may be cut or used for connecting other profiles, such as ornaments or roof structures, with the aid of the external thread 11.

The presented drawings are only illustrative examples and do not limit the scope of the invention. It is evident for professionals that form linings of a shape different from those presented can also be covered with a flexible pad 1, the invention may be therefore suitable for casting profiles of several different shapes, depending on the shape of the form lining. The invention may be used as a supplement to the known formworks, for example in case of quadrilateral and circular column formworks, slab formworks, circular wall formworks, arched formworks and free-form formworks. The form lining 2 may be a sphere or a cone, its inner surface can be covered with the flexible pad 1.

The advantage of the invention is that, while the known formworks are suitable for casting only concrete walls, the padded formwork in accordance with the invention allows the casting of profiles which have visible stone surfaces and which are made of binder and of stones of at least 40 mm in diameter and which are characterised in that after curing of the binder and removing of the padded formwork, the stones are showing without being cleaned from the binder in a separate step or without the binder in the joints requiring separate finishing process or other treatment.