DESCRIPTION

The present patent relates to stay-in-place formwork for the building industry and particularly concerns a new plant for the production of self-supporting stay-in-place formwork made of a foam material with a metal stiffening reinforcement, for use in the preparation of floors and ceilings, generally made of reinforced concrete.

There are known types of formwork for the preparation of concrete floors, which may be of the reusable or stay-in-place type.

The known stay-in-place formwork commonly consists of elements made of polystyrene foam, in a generically parallelepiped shape, on the lateral or upper surface of which there are longitudinal seats suitable for containing metal reinforcement bars for the preparation of the reinforced concrete floor members.

There are known stay-in-place forms for use in floor construction that comprise two half-forms, made side by side so as to obtain a whole form by means of the juxtaposition of two half-forms, and there are also known types of stay-in-place formwork for floor construction that have a central seat.

The stay-in-place formwork of known type typically has a modular width corresponding to the distance between the centres of the floor joists, e.g. approximately 600 mm, and a length sufficient to cover the span or section of floor, that is generally of the order of a few metres. Said stay-in-place formwork is laid and supported directly on the joists or lintels, and must be supported by means of a temporary intermediate reinforcement. Said stay-in-place formwork provides a flat surface at a given elevation, on which the concrete floor can then be cast.

Said formwork has the advantage of being far lighter than the known concrete slabs, or the known ribs with hollow bricks, and it is consequently easier to move and install.

On the other hand, using said stay-in-place formwork makes it necessary to provisionally install some intermediate reinforcement for support, which must remain in place at least until the concrete has set completely.

The known self-supporting formwork also comprises one or more metal reinforcement bars or sheets, embedded and/or arranged longitudinally in the polystyrene foam body.

Said metal reinforcement serves the purpose of supporting not only the self weight of the formwork installed, but also and more importantly the weight of the reinforcement bars, of the cast concrete and of the workers preparing the ribbed floor.

A further advantage deriving from the use of the known stay-in-place formwork lies in that the foam material used to prepare said formwork has excellent thermal and acoustic insulation properties.

The known formwork also comprises metal elements, integral with or incorporated in the underside, designed to enable the subsequent connection, with the aid of screws, of panels (made of plasterboard, for instance) for covering the underside or of nets for the application of plaster.

The known formwork made of polystyrene foam with inner metal reinforcement is usually made by expansion of the polystyrene with the aid of steam in suitable moulds, in which the metal reinforcement bars or sheets have been already inserted.

Thus, to make the known stay-in-place formwork, it is necessary to prepare a mould of a given size and shape, to suitably arrange the metal bars therein and then proceed with the expansion of the polystyrene.

The production process is consequently discontinuous and severely limited by the time it takes to position the reinforcement and to expand the material.

The object of the present patent is a new plant for the production and cutting to size of formwork made of an insulating material with a metal reinforcement.

One object of the new plant is to produce forms made of insulating material and a metal reinforcement of any length required and substantially in an uninterrupted process.

Another object of the new plant is to produce formwork made of insulating material and a metal reinforcement of any required size without using or having to prepare specific moulds.

Another object of the new plant is to prepare the metal reinforcement for the formwork at the time of their use in the making of the form. Another object of the new plant is to prepare said metal reinforcement continuously and with no size restrictions.

Another object of the new plant is to produce formwork made of an insulating material and metal reinforcement with no waste or scraps. These and other, direct and complementary objects are achieved by the new plant for the production and cutting to size of formwork made of insulating material with a metal reinforcement and comprising at least one metal reinforcement loader-feeder unit, at least one dual- head reinforcement bar welding unit, at least one unit for feeding the metal reinforcement bars forward, at least one mould or chamber for moulding, expanding and sintering the insulating material, and at least one cutting unit for cutting the formwork to the required size.

The metal reinforcement loader-feeder unit comprises a storage area where the metal reinforcement for the formwork is stacked. In particular, said loader-feeder unit is suitable for containing generically linear meshed metal reinforcement elements consisting of three parallel linear bars placed at the vertices of a triangle and two bars with a generically undulating shape connecting the two lower bars to the upper bar.

These metal reinforcement elements are sent, one after the other, towards the welding unit, which welds together the rear end or head of the parallel bars of the metal reinforcement already fed forward to the front ends or head of the parallel bars of the following metal reinforcement element.

For this purpose, short lengths of bar are attached alongside and welded in line with the ends of the bars of the two reinforcement elements so as to ensure the continuity of said bars at the vertices of the triangle.

At least two metal reinforcement loader-feeder units can be used with corresponding welding units so as to enable a continuous production of forms complete with two or more parallel metal reinforcement elements.

Mechanisms or devices are provided for the attachment and/or fixing of a linear metal member, typically with a "U"-shaped profile, underneath each metal reinforcement element to serve as means for fixing floor covering panels, such as plasterboard panels.

The metal elements for reinforcing the forms, thus arranged, are fed forward and positioned inside the insulating material mould or moulding, foaming and sintering chamber.

In particular, said mould or moulding chamber comprises lateral and upper and lower walls parallel to the length of the metal elements for reinforcing the form and it has the profile of the cross section of the form being made, with a front inlet wall facing towards the metal reinforcement loader-feeders and the welding units.

In particular, said inlet wall of the mould or moulding chamber includes openings to enable the transit of said metal reinforcement elements, as well as means and devices designed to enable the transit of said metal reinforcement elements through said openings during the forward feed stages, and to seal said openings in said inlet wall hermitically around the bars and the other components of the metal reinforcement passing through said inlet wall.

The rear outlet part of the mould or moulding chamber is initially closed by an element made of foamed plastic material identical to the plastic material with which the form is made and having the same cross section as the form being made.

Both the lateral walls and the upper wall or ceiling of the mould or moulding chamber can be moved laterally and parallel to their original position to enable the preparation of moulds of different width and/or height.

On the outside of the mould or moulding chamber, at the end where the prepared form exits, there is a containment sleeve and a cutting unit installed on a mobile trolley.

The containment sleeve comprises walls arranged in the shape of a tubular duct through which the newly-made form transits. This sleeve maintains the shape and size of the newly-made form in the area adjacent to where the form exits from the mould or moulding chamber.

The cutting unit is installed on a trolley sliding parallel to the direction in which the form exits from the mould or moulding chamber.

Said trolley enables the cutting unit to be moved into the required position along the length of the stretch of newly-made form already outside the mould or moulding chamber.

The cutting unit comprises an upper and a lower cutter.

Said upper cutter conveniently consists of a heated metal wire designed to cut the upper part of the plastic material of the newly- made form.

Said lower cutter conveniently consists of a circular blade designed to cut the underside of the form and particularly the metal bars for reinforcing the form.

Said cutting unit is normally positioned orthogonal to the direction in which the newly-made form moves forward, but mechanisms are provided for tilting it in both the vertical and the horizontal plane. The mould or moulding chamber may be equipped so as to enable the preparation of a double form, i.e. a form in the shape of two juxtaposed forms. To achieve the central groove for the ribbing of the floor, the mould or moulding chamber is consequently fitted with a movable or modifiable vertical wall parallel to the lateral walls of the mould or moulding chamber and to the direction in which the form is fed forward.

This vertical wall preferably comprises an upper support to which two partitions are attached that are parallel to one another and to the lateral walls of the mould or moulding chamber. In particular, said partitions have an upper edge attached to said support and a lower edge free. A bending bar is hinged or otherwise attached and connected to said two lower edges of said two partitions. Said bending bar may be raised or lowered by a mechanism equipped with a cam connected to said upper support. The raising of said bar between said two partitions thus causes the lower edges of said partitions to move closer together, thereby acquiring a generically "V"-shaped arrangement, while the lowering of said bar makes the lower edges of said partitions spread apart and thus occupy a position generically parallel to one another. Below is a description of the main aspects of the operation of the new plant for the production and cutting to size of formwork made of insulating material and containing a metal reinforcement.

The rear outlet end of the mould or moulding chamber is initially closed by an element made of an expanded plastic material identical to the plastic material with which the form is to be made, and having the same cross section as the form being made.

The metal reinforcement elements are sent to the mould or moulding chamber and, if necessary, they are connected to subsequent metal reinforcement elements so that the mould or moulding chamber contains a continuous metal reinforcement element covering the full length of injection of the mould or moulding chamber.

The means and devices for sealing the openings in the inlet wall around the bars and other components of the metal reinforcement elements are then operated.

The plastic material comprising the form is injected, moulded or otherwise inserted in the mould or moulding chamber.

If necessary, steam is delivered inside the mould or moulding chamber so as to induce the expansion and/or sintering of the plastic material. When the plastic material has solidified sufficiently, the means and devices for sealing the openings in the inlet wall around the bars and other components of the metal reinforcement are moved away and the unit for feeding the front metal reinforcement elements into the mould or moulding chamber forward is operated. The metal reinforcement elements in front of the mould or moulding chamber are inserted in said mould or moulding chamber.

Said operation for feeding the front reinforcement elements forward into the mould or moulding chamber ejects the previously-made form still contained in the mould or moulding chamber through the outlet end of the mould or moulding chamber.

In particular, this forward feeding of the previously-made form does not discharge the full length of said form from the mould or moulding chamber, but only a portion thereof, so that a stretch of the newly- made form remains inside the mould or moulding chamber and serves to close the mould or moulding chamber on the side from which the previously-made form is discharged.

The insulating material subsequently injected, sintered and moulded inside said mould or moulding chamber creates a further volume corresponding to the space left free inside the mould or moulding chamber, bonding to the surface of the previously-made form serving as the end wall of the mould or moulding chamber.

The two portions of insulating material, moulded one after the other, thus constitute a single, uninterrupted body with continuous internal metal reinforcement elements.

The subsequent forward feed of the metal reinforcement elements at the front of the mould or moulding chamber discharges the newly- made portion of the form.

The newly-made portion of the form discharged outside the mould or moulding chamber is supported and contained by the containment sleeve so that the steam and heat of the subsequent moulding operations do not substantially modify the shape of the newly-made portion of the form.

When necessary, the cutting unit is moved laterally along the newly- made form to cut the front portion of the continuous form to the required length.

The characteristics of the new plant for the production and cutting to size of formwork made of metal-reinforced insulating material are better clarified in the description that follows with reference to the drawings, attached as a non-limiting example.

Figure 1 schematically shows the new plant as a whole, comprising a unit (A) for loading and feeding the metal reinforcement elements (S), a dual-head unit (B) for welding metal bars and wires, a unit (G) for loading the profiles for the underside, a unit (C) for feeding the metal reinforcement elements (S) forward, a mould or moulding chamber (D) for the expansion and sintering of the insulating material, a containment sleeve (E), a cutting unit (F) for cutting the newly-made form to the required size, and a roller bed (H) for unloading the form. The unit (A) for loading and feeding the metal reinforcement elements (S), shown in figure 2, is designed to contain generically linear meshed metal reinforcement elements (S) comprising three parallel linear metal bars arranged at the vertices of a triangle and two bars with a generically undulating shape connecting the two lower bars with the upper bar.

The loader-feeder unit (A) sends said metal reinforcement elements (S), one after the other, towards the welding unit (B), which welds the rear end or head of the parallel bars of the metal reinforcement element (S) already fed forward to the front ends or head of the parallel bars of the subsequent metal reinforcement element (S).

Figure 3 is an axonometric view of a welding unit (B).

At least two units (A) for loading-feeding the metal reinforcement elements (S) can be used, with corresponding welding units (B), so as to enable the preparation of continuous forms complete with two or more parallel metal reinforcement elements (S).

The unit (G) for loading the lower profiles attaches or fixes a linear metal member, typically with a "U"-shaped profile, to the underside of each metal reinforcement element (S) to serve as means for fixing floor covering panels, such as plasterboard panels.

Figure 9 shows a view of the unit (C) for feeding the metal reinforcement elements (S) forward.

The forward feed of the metal reinforcement elements (S) in the loader-feeder unit (A) is achieved by means of a pneumatic piston (CI) with pneumatic jaws (C2) designed to grip the upper bar of each metal reinforcement element (S).

The metal reinforcement elements (S) are sent to and contained in the mould or moulding chamber, where the insulating material is expanded and sintered.

Figures 4 and 5 show several views of the mould or moulding chamber (D) comprising lateral walls (Dl, D2), and upper (D3) and lower (D4) walls having a profile coinciding with the cross section of the form being made, and an inlet wall (D5) facing towards the metal reinforcement loader-feeder units.

In particular, the inlet wall (D5) of said mould or moulding chamber (D), shown in figure 6, includes openings (D51) designed to enable the transit of said metal elements (S), and also means and devices (D52) designed to enable the transit of said metal reinforcement elements (S) through said openings (D51) during the forward feed stages and then, during the moulding or injection stages, to hermetically seal said openings (D51) in said inlet wall (D5), around the bars and the other components of the metal reinforcement (S) passing through said inlet wall.

Both the lateral walls (Dl, D2) and the upper wall, or ceiling (D3) of the mould or moulding chamber (D) can be moved parallel to their positions to enable the production of forms of different width and/or height.

The mould or moulding chamber (D) includes a movable or modifiable central wall (D6), parallel to the side walls (Dl, D2) of the mould or moulding chamber (D) and to the direction in which the form is fed forward, that enables the production of a double form, i.e. a form in the shape of two juxtaposed forms.

Said central wall (D6), shown in figures 7a and 7b, comprises an upper support (D61) to which two partitions (D62), parallel to one another and to the lateral walls (Dl, D2) of the mould or moulding chamber (D), are attached. Said partitions (D62) have an upper edge attached to said support (D61) and a lower edge left free. A bending bar (D63) is hinged or otherwise included and connected to said two lower edges of said two partitions (D62). Said bending bar (D63) is raised or lowered by a mechanism fitted with a cam (D64) connected to said upper support (D61). Raising said bar (D63) between said two partitions (D62) brings the lower edges of the partitions (D62) closer together, giving them a generically "V"-shaped arrangement (figure 7a), while lowering said bar (D63) makes the lower edges of the partitions (D62) spread apart, into a position in which they are generically parallel to one another (figure 7b).

There is a containment sleeve (E) on the outside of the mould or moulding chamber (D), on the side where the previously-made form exits.

The containment sleeve (E) comprises walls that take the shape of a tubular duct through which the newly-made form transits. Said sleeve maintains the shape and size of the newly-made form in the area adjacent to the point where the form exits from the mould or moulding chamber (D).

The cutting unit (F) is located beyond the containment sleeve (E), in the direction in which the newly-made form exits.

The cutting unit (F), shown in figure 8, is installed on a trolley (F3) that slides parallel to the direction in which the form exits from the mould or moulding chamber (F).

Said trolley (F3) enables the cutting unit (F) to be moved into a suitable position along the length of the newly-made portion of form outside the mould or moulding chamber (D). The cutting unit (F) comprises an upper cutter (Fl) and a lower cutter (F2).

The upper cutter (Fl) consists of a heated metal wire suitable for cutting the upper part of the plastic material of the newly-made form, while the lower cutter (F2) consists of a circular blade suitable for cutting the lower part of the newly-made form, and the bars of the metal reinforcement in the form in particular.

Said cutting unit (F) is normally positioned orthogonal to the direction in which the newly-made form is fed forward e, while mechanisms are provided to enable it to be tilted in both the vertical and the horizontal plane.

Beyond the cutting unit (F), there are one or more roller beds (H) for receiving each newly-made form.

Thus, with reference to the above description and to the attached drawings, the following claims are advanced.