FR2469524A1 - Modular prefabricated hood for fire place - has part truncated pyramid form using precast planks half housing onto angle and joint posts - Google Patents

Abstract

The hood has a part pyramid form and is used over domestic open hearth fires. It is made from a standardised range of precast panels (3) and posts (4,5). An angle hood may have two sides (2,3a) which constitute adjacent sides of a truncated right pyramid. The components are made from a mix of plaster, cement and an expanded lightweight aggregate such as vermiculite or expanded perlite. Components are cast in moulds of expanded polystyrene or similar which remain in place to package the products, and inter component joints use plaster coated tow or adhesive. The joints may be of the half housed- half-concealed type with wall panels (3) to standard sizes.

Description

The present invention relates to prefabricated domestic chimney hoods as well as the prefabricated elements and the methods for building them.

 The technical sector of the invention is that of the construction of hoods for covering domestic fireplaces.

In a prior patent application FR 77/31094, chimney hoods have been described which are constructed by assembling factory prefabricated panels on site, which are composed of a mixture of plaster, a binder and an expanded mineral product. , for example vermiculite or expanded perlite, and which can optionally be reinforced by a reinforcement, for example a rib panel.

The objective of the present invention is to provide improvements to the methods of construction of these prefabricated chimney hoods
A domestic chimney hood constitutes a decorative and therefore very visible part of a housing and an essential quality of such a hood is to present visible surfaces having a very good surface condition and non-spalled edges. However, the prefabricated plaster panels mixed with vermiculite or expanded perlite have a certain fragility and are exposed to being scratched, stained or damaged during transport and storage between prefabrication and assembly on site.

A first objective of the present invention is to overcome this difficulty.

 Domestic chimney hoods can have various shapes and sizes, which would complicate prefabrication and would make it very expensive if it were necessary to prefabricate elements adapted to each shape of hood and each dimension.

 A second objective of the invention is to reduce the cost price by prefabrication of series of standardized elements which can be cast in identical molds and which are then easily adjusted on site thanks to the properties of the material which composes the prefabricated elements. .

 The objectives of the invention are achieved by means of prefabricated domestic chimney hoods which are composed of prefabricated panels of rectangular shape and of prefabricated bars which constitute the edges and possibly the junctions between panels which panels and bars are composed of a mixture of plaster, a curable binder and a low density expanded mineral product such as vermiculite or expanded perlite.

The methods of constructing chimney hoods according to the invention include the following steps
- said panels and said bars are prefabricated in the factory by pouring the mixture into molds made of a low density material, in particular of expanded polystyrene;
- said panels and said bars are transported and stored in a mold glow which serves as lost packaging;
- Etonoenstruitles hoods by assembling said panels on site with each other and with said bars by means of invisible seals, in particular gaskets filled with pigtail braids coated in molding plaster or glued joints.

Preferably, series of rectangular panels and identical bars having standardized dimensions are prefabricated and during the construction of the hood, said panels and said bars are adjusted to the dimensions and shape of the hood by sawing them.

 Advantageously, the panels and the prefabricated bars are sawn in their lost packaging and the packaging is sawn at the same time as the panel or the bar.

 The prefabricated rectangular panels are cast in series in molds of identical dimensions. They have rebates along their four sides. The rebates along two adjacent sides are in the same direction and the rebates along two opposite sides are in the opposite direction.

The invention results in prefabricated domestic chimney hoods. Thanks to the transport of the prefabricated elements in molds made of polystyrene or any other equivalent cellular material, the visible faces of the prefabricated elements are protected during all handling between the prefabrication factory and the assembly site and retain their raw demoulding appearance and a perfect surface finish. The polystyrene molds are light, so that the weight to be transported is increased in very small proportions. In addition, the prefabricated elements contained in their mold can be stacked or stacked without risking scratching or damaging them.

 Another advantage of the chimneys according to the invention composed of panels and bars lies in the fact that it is possible to prefabricate in identical molds series of panels or bars of standardized dimensions which can then be adjusted to the dimensions required by the shape and size of the chimney hood by sawing them.

 Advantageously, sawing is carried out by leaving the panels in their polystyrene formwork which is easy to saw and which is sawn at the same time as the panel, so that the panel is protected from any contact with the ground and from any risk. deterioration during the sawing operation.

The panels according to the invention are prefabricated uniformly with rebates along their four edges, which makes it possible to directly assemble a panel with another panel which is juxtaposed or superimposed on it or to assemble it with an edge or with a connecting bar.

When the rebate is not necessary for assembly, it is removed by sawing.

The following description refers to the appended drawings which represent, without any limiting nature, exemplary embodiments of prefabricated chimneys according to the invention.

 Figure 1 is a perspective view of a domestic chimney comprising a prefabricated hood according to the invention.

 Figures 2, 3 and 4 are partial sections of Figure 1 along the lines II-II, 111-111 and IV-IV.

Figure 5 is a variant of a partial section along the line III-III.

Figure 6 is a partial perspective and exploded view of a prefabrication mold of a panel and a panel.

Figure 7 shows in perspective a section of the prefabricated mold of a linear element and in exploded view, a section of prefabricated element.

FIG. 1 represents a domestic chimney comprising a prefabricated hood 1 which covers a drain located behind the hood. Illustrated, by way of example, a corner chimney comprising only a front face 2 and a lateral face 2a. Of course, this example is not limiting and the invention also applies to chimney hoods having two side faces.

 The chimney shown in Figure 1 has the shape of a pyramid trunk, that is to say that the faces 2 and 2a are planar and inclined relative to the vertical and have a width at the base greater than the width at the top. Of course, this is only a non-limiting example.

It is also possible to construct chimney hoods according to the invention having an inclined front face whose width is the same at the base and at the top and vertical side faces whose width at the base is greater than the width at the top or even straight chimney hoods with vertical faces the same width at the base and at the top. It is also possible to construct chimneys according to the invention of rounded shape having a curved horizontal section.

A chimney hood according to the invention is composed of prefabricated elements which are, on the one hand, panels 3 of rectangular shape and, on the other hand, linear elements or bars which serve to produce the edges 4 and possibly the 5 junctions between panels.

 The elements 3, 4, 5 are prefabricated in the factory by pouring into molds a pasty mixture containing plaster, a curable binder, for example white cement, lime or a glue in polymerizable resin and an expanded mineral product such as vermiculite or expanded perlite. A reinforcement can optionally be placed in the mold, for example a ribbed reinforcement panel to reinforce the prefabricated panels 3.

On the construction site, the prefabricated panels 3 are assembled together, either edge to edge, or on prefabricated edges or on connecting bars 5. On the construction site, the joints are lined with woven braids coated in plaster to be molded, then are smoothed with a spatula.

The joints can also be glued joints.

 In Figure 1, we have drawn the joints between panels as well as the joints located at the junction between the panels 3 and the edge 4 to clearly show the cutting of the hood, but of course, when the hood is finished, these joints are not visible and the hood has a smooth and uniform surface.

 According to a characteristic of the invention, the prefabricated elements 3, 4, 5 are cast in the factory, in molds and are then stored and transported in their mold which serves as lost packaging and which protects the prefabricated element during handling. Preferably, these molds or forms are made of expanded polystyrene or any other cellular material and of low equivalent density, for example polyurethane foam.

According to another characteristic of the invention, the rectangular panels 3 are prefabricated in series in molds of the same standardized length.

 On the construction site, the panels and the linear elements are then adjusted to the dimensions and to the shape of the hood and this adaptation is carried out very easily and very cleanly by sawing because the material which composes the prefabricated elements is very easy to saw even with a hand saw and a very precise and very clear sectioning is thus obtained, requiring no retouching.

 According to another characteristic of the invention, the sawing of the panels or of the prefabricated linear elements is carried out, preferably, by keeping the panel or the prefabricated element in the lost mold and by sawing at the same time the mold which is very easy to saw and the prefabricated material. This prevents the visible surfaces of the panels or the edges from being damaged during the sawing operation.

 The prefabricated panels 3 have dimensions which allow them to be handled easily without a lifting device. For example, the panels 3 are rectangular panels having 1 m long, 0.50 m wide, a thickness of approximately 10 cm and a weight of the order of 40 Kgs.

 In the example shown in FIG. 1, the lateral face 2a has for example less than one meter in width at the base and a little more than one and a half meters in height. It is built by superimposing four prefabricated panels 3 and the upper panel is sawn to adjust its height to that of the hood.

 In this example, the width of the face 2a at the base is greater than the width at the top. The prefabricated panels are sawn along their edge which joins with edge 4 to give them a shape of a rectangular trapezoid.

 Similarly, the front face 2 is divided into two zones. A first zone situated against the wall has a rectangular shape and a width equal to that of the panels 3 and it is constructed by superimposing prefabricated panels. The height of the top panel is adjusted by sawing. On the other hand, the second zone situated against the edge 4 has a trapezoidal shape and the prefabricated panels are sawed according to a rectangular trapezium whose edge which comes to assemble at the edge is oblique.

 FIG. 6 represents, in perspective and in exploded view, a section of mold 6 made of polystyrene intended for the prefabrication of the panels 3 and a section of panel 3 prefabricated in the mold 6. The mold 6 has the shape of an open rectangular box to the upper part which is laid flat for example on a work table which can be a vibrating table. The mold 6 has stepped recesses 6a along two of its neighboring edges. Along the other two edges, the mold 6 has a hollow notch 6b. Prefabricated in such molds, which have standardized dimensions, series of identical panels 3, which include square rebates 7, 8, along their four sides. The rebates 7 which reproduce the shape of the stairs 6a are in the opposite direction to the rebates 8 which are obtained by the notches 6b. It can be seen that the rebates situated along two opposite sides of a panel 3 are in the opposite direction one of the other.

2 shows a vertical section on which we see the assembly of the rebates of the juxtaposed panels. Thanks to this inverted arrangement of the rebates, each panel 3 rests on the one it overcomes.

 FIG. 6 represents an example of prefabrication of 3-plane panels, but it is clearly specified that the molds 6 can be curved or curved molds making it possible to prefabricate curved panels.

 In certain assemblies described below, the rebates 7 or 8 are not necessary and, in this case, it is easy to remove them by sawing during the assembly of the site. It is more economical to provide them in all cases during the prefabrication because it allows to carry out serial prefabrications of identical panels which meet all the construction cases and the removal on site of superfluous rebates is an easy operation to achieve.

It can be seen that the demolding of the rebate which forms in the notch 6b cannot be carried out without breaking the mold 6, but since these are lost molds, inexpensive, made of an easy-to-break material, this does not has no practical importance.

FIG. 7 shows, in exploded view, a section of mold 9 made of expanded polystyrene and a section of edge 4 prefabricated in the mold 9.

 The mold 9 is composed of two halves 9a and 9b symmetrical with respect to a joint plane 10, which are kept assembled by any means, for example by gluing.

 As can be seen, this mold is of elongated shape and makes it possible to prefabricate bars 4 of determined length. The cross section of these bars 4 is inscribed in a square represented by dotted lines, one of the vertices 12 of which corresponds to the visible edge, is placed at the bottom of the mold.

The two opposite vertices, located on either side of the vertex 12, are replaced by an angled rebate 13a and 13b, which is obtained by means of two ribs îîa and îîb in the shape of a right triangle placed along the side walls of the mold. Finally, the fourth vertex of the square, which is opposite the edge, is replaced by a truncation 14 located in the upper horizontal plane of the mold.

 Figure 3 shows a section on III-III, on which we can clearly see the edges of two panels, placed in the rebates 13a and 13b of a bar 4 whose top 12 serves as an edge of the hood.

In this example, the depth of the rebates 13a and 13b is equal to the thickness of the panels 3. As a variant, the depth of the rebates 13a and 13b can be equal to that of the rebates 7 and 8 of the panels 3 and, in this case, the assembly is done by fitting the two rebates.

5 shows in cross section, an alternative embodiment of prefabricated bars 4a and the assembly with two prefabricated panels 3. In this example, the cross section of a bar 4a has the shape of a rectangle or a square of which a vertex 12a serves as an edge and of which the two opposite vertices, situated on either side of the edge, are notched in the form of a rebate 15a, 15b to receive the edge of a prefabricated panel 3. In the example shown, the depth of the rebates 15a and 15b is equal to the thickness of a panel 3, but as a variant, it could also be equal to the depth of the rebates 7 and 8.

 Figure 4 shows a section through a vertical junction between two juxtaposed panels. These junctions can be carried out by assembling the panels edge to edge as shown in FIG. 2. However, in certain cases, in particular for constructing large hoods, these junctions can be produced by means of prefabricated bars 5 in the form of Tee, which delimit two rebates 16a, 16b, the depth of which is equal to the thickness of the panels 3. The leg of the tee is arranged between the edges of the two panels and the head of the tee is placed inside the hood.

 The materials are poured into the molds 6 and 9 and into the molds used for the prefabrication of the bars 4 and 5, by placing the molds flat, for example on a vibrating table and by troweling the top of the prefabricated elements with a trowel. to equalize the surface with that of the upper plane of the molds. The visible faces after assembly of the chimney are preferably those which are placed in contact with the mold, which have a good surface appearance and which are well protected during handling.

It can be seen, by examining FIGS. 6 and 7, that it is easy to superimpose molds containing the prefabricated elements during transport.

 Of course, without departing from the scope of the invention, the various elements constituting chimney hoods and molds which have just been described by way of example may be replaced by equivalent elements fulfilling the same functions.

 The rebates 7, 8 of the panels as well as the rebates 13a, 13b, 15a, 15b, 16a, 16b can be replaced by equivalent assembly means, for example by tenons and mortises, in particular tenons and mortises in the shape of a tail. dovetail.

Claims (9)

1 - Prefabricated chimney hood, characterized in that it is composed prefabricated panels, rectangular, and prefabricated bars  bricks, which constitute the edges and possibly the junctions  between panels, which panels and bars are composed of a mixture  plaster, a curable binder and an expanded mineral product of  low density such as vermiculite or expanded perlite. 2 - A method of constructing chimney hoods according to claim 1, characterized in that - said panels and said bars are prefabricated in the factory by pouring mixing in molds of a low density material, in particular  expanded polystyrene; - said panels and said bars are transported and stored in  their mold which serves as a lost packaging;  - and the hoods are built by assembling said panels on site  between them and with said bars by means of invisible joints, in particular gaskets filled with braid of tow wrapped in plaster to be molded or glued joints. 3 - Method according to claim 2, characterized in that it is prefabricated series of rectangular panels and identical bars having  standardized dimensions and, during the construction of the hood, adjusts said panels and bars to size and shape  from the hood by sawing them. 4 - Method according to claim 3, characterized in that the said panels and said bars in their lost packaging and we saw  at the same time said packaging. 5 - Prefabricated rectangular panels to build hoods chimney according to claim 1, characterized in that they are cast  in series in molds of identical dimensions, which they include  rabbets along their four sides and that the rabbets if killed along two adjacent sides are of the same direction and the rabbets  located along two opposite sides are in opposite directions. 6 - Prefabricated bars to build the edges of chimney hoods  according to claim 1, characterized in that they are cast in  series in molds of standardized length. 7 - Prefabricated bars according to claim 6, characterized in that their cross section fits into a square or rectangle, one of which  vertices constitutes the edge, that the two opposite vertices situated on the side and  other of said edge are replaced by a rebate which receives the edge of a prefabricated panel. 8 - Prefabricated bars according to claim 7, characterized in that  the fourth vertex which is opposite the edge is truncated. 9 - Prefabricated bars to construct junctions between panels according to  claim 5, characterized in that their cross section pre  feels the shape of a T which delimits two rebates which each receive  one edge of a prefabricated panel.