BE1020106A3 - BLOCK AND MOLD PRESS FOR MANUFACTURING A HOLLOW CONCRETE BLOCK WITH A BACKWALL AND METHOD OF MANUFACTURING A HOLLOW CONCRETE BLOCK BY A BLOCK PRESS. - Google Patents

Abstract

The press comprises a support plate of a block (10) defining an outer mold (30) with an inner core (40) defining between them a volume corresponding to the side walls (11), the inner core (40) arranged to extend away from the tray to define together a volume corresponding to the bottom wall (12). The press comprises means for compacting the concrete in the volume of the side walls (11) and the outer mold (30) comprising means (50) for horizontal settlement of the concrete in the volume of the outer mold corresponding to the bottom wall (12). ).

Description

The invention relates to the manufacture of hollow concrete cans with a bottom. The invention relates to the manufacture of a hollow concrete block with a bottom wall and to a method of manufacturing by a block press of a hollow concrete block. and in particular junction boxes of a plurality of liquid lines, and more particularly, junction boxes for rainwater transmission pipes and / or for transporting wastewater of a dwelling.

When it is desired to connect one or more liquid lines to one or more evacuation lines, it is possible to use a hollow connection box having orifices into which said ducts open, the volume of the box thus constituting the placing in communication pipes with each other. Such a box eventually fulfills the role of a collector.

In use, the liquid or the inlet pipe enters the internal volume of the junction box and then flow into the outlet pipe or pipes, the junction box ensuring continuity in the conduct of the liquid between the pipes. Thus, the junction box must be watertight to prevent any leakage of liquid.

By way of example, with reference to the schematic figure 1, a connection box 10 is connected at the inlet to sanitation pipes 1, 2 carrying waste water from a shower and a sink of a dwelling. and at the outlet to a discharge pipe 3 of the wastewater to a sanitation nozzle 4.

Conventionally, a junction box is in the form of a hollow parallelepiped concrete box with a solid bottom wall and side walls comprising (at least for some) orifices for receiving the ends of the liquid pipes. The upper face of the box is removably closed by a hood that can be lifted to inspect the interior volume of the box and, if necessary, remove debris disrupting the flow of liquid.

Traditionally, a junction box is made according to a tedious manufacturing process. This method requires the use of a parallelepipedal mold with an open face, defining the outer shape of the box, and a core defining the inner shape of the box. The core is placed in the outer mold and concrete is poured between them and above the core, thus filling a volume corresponding to that of the side walls and bottom of the junction box, arranged upside down. The set is packed, returned and unmolded to obtain the junction box. Such a process is long and poorly suited to production of an industrial nature.

Also known are presses of the type "block press" arranged to efficiently manufacture industrial blocks of concrete. Nevertheless, such blocks generally do not comprise a bottom wall. If they include, their use does not require that the wall has a density and sealing comparable to those required for the bottom wall of a junction box, which must be completely waterproof. Therefore, block presses are not suitable for the manufacture of junction boxes.

The aim of the invention is to propose a method of manufacturing connection boxes that is effective and can be implemented industrially.

The invention arose from a problem relating to connection boxes but the applicant does not intend to limit the scope of its rights to this application, the invention applies more generally to the manufacture of hollow concrete blocks with a background.

Thus, the invention relates to a block press for the manufacture of at least one hollow concrete block with side walls and a bottom wall, the press comprising a horizontal support plate of the block during its manufacture an outer mold with an inner core arranged to define between them a volume corresponding to the side walls of the block, the inner core being arranged to extend away from the plate to define with it a volume corresponding to the bottom wall of the block, the press further comprising means for vertical settlement of the concrete in the volume corresponding to the side walls of the block and the outer mold comprising means for horizontal settlement of the concrete in the volume of the outer mold corresponding to the bottom wall of the block.

A block press according to the invention makes it possible to industrially produce blocks having a bottom of large and homogeneous density, since it is packed. This makes it possible to obtain connection boxes whose bottom is sealed according to a manufacturing process whose duration is advantageously reduced. When the mold is removed, the block formed is thus directly supported by the tray which can convey it to a drying zone for example.

Preferably, the horizontal packing means comprise at least one tamping pylon actuated by a jack, the pest exerting a compressive force along a packing axis.

A pestle is used to exert a force distributed in the mold so as to form a bottom wall of homogeneous density. ______

More preferably, the tamping pestle is arranged to be drivable in horizontal translation, preferably in a reciprocating motion.

The movement of the pestle advantageously makes it possible to compact the concrete in the mold by exerting a plurality of elementary compressions, which makes it possible to compact the concrete in a graduated manner so as to gradually increase the density of the bottom wall.

Still preferably, the outer mold having side walls, the tamping pestle is in the form of a horizontal arm arranged near an end of a side wall of the outer mold. This is possibly the lower end of the side wall.

Preferably still, the tampon has a vertical thickness equal to a thickness of the bottom wall of the block to be manufactured. The pestle thus exerts a homogeneous compressive force in the volume defining the bottom wall of the mold.

Preferably, the outer mold comprises two tamping pencils mounted opposite each other on the outside mold and controlled so as to exert opposite-direction compression forces directed towards the inside of the outer mold. The use of two tamping pestles makes it possible to rapidly densify the bottom wall of the block. In addition, the density that can be obtained for the bottom wall is greater with two tamping pestles. Preferably, these drumsticks are coordinated to perform their movements back and forth concomitantly, their movements to the inside of the outer mold being simultaneous.

According to another characteristic of the invention, the inner core and the support plate are arranged so that the distance between them decreases as one moves inwardly from the side walls of the outer mold, along said settlement direction.

Thus, the shape of the volume defining the bottom wall of the block combines with the pestle to promote the compression of the concrete; indeed, reducing the distance between the walls of the inner core and the support plate physically causes a compression of the concrete when pushed in the direction of the distance reduction. The formation of the bottom wall is thus accelerated and makes it possible to obtain a bottom wall of high density.

According to another characteristic of the invention, the press comprises a punching module arranged to punch at least one side wall of the block, the punching module comprising a punch having the shape of a circular arc extending preferably around an angle at the center strictly less than 360 ° and preferably greater than 340 °. This advantageously makes it possible to form on the wall a breakable zone whose dimensions correspond to a fluid pipe duct; thus, to form a connection port to a pipe, it suffices to break the breakable zone. The use of such a punch has the advantage of forming a breakable zone which only the outer limits are recessed in the side wall, preserving the integrity of the latter when the breakable area is not broken.

Preferably, the parts of the side wall located inside and outside the circular arc whose punch has the shape being connected by a support cord, the punching module is arranged to punch the side wall so that the support cord extends in the lower position of the arc of the side of the horizontal support plate.

After unmolding, the support cord makes it possible to support the breakable part of the lateral wall (situated inside the arc of a circle) in order to prevent the latter from collapsing, due to its weight, during the drying, on the unscored part of the side wall (located outside the arc). Due to the shape of the punch, the dimensions of the punched area are not changed during drying.

The invention also relates to a mold for the manufacture of at least one hollow concrete block with side walls and a bottom wall, for use in a block press, comprising: a body having lateral walls; extending between an upper face and a lower face, the body being open by its upper and lower faces; and horizontal concrete packing means in a volume corresponding to the bottom wall of the block.

Such a mold has the same advantages as the press defined above.

Preferably, the mold comprises an inner core having a bottom, the core being suspended in the body of the mold so as to define between them a volume corresponding to the side walls of the block and under the bottom of the core a volume corresponding to the bottom wall of the block. By dimensioning the dimensions of the mold and the core, it is possible to manufacture hollow blocks of various shapes and of homogeneous density.

According to various embodiments of the invention, the mold comprises the characteristics of the mold of the press defined above.

The invention also relates to a method of manufacturing, by a block press, at least one hollow concrete block with side walls and a bottom wall, the block press comprising: a horizontal support plate of the block during its manufacture, - an outer mold with an inner core arranged to define between them a volume corresponding to the side walls of the block, the inner core being arranged to extend at a distance from the tray to define with it a volume corresponding to the bottom wall of the block, the press further comprising means for vertical settlement of the concrete in the volume corresponding to the side walls of the block and the outer mold comprising means for horizontal settlement of the concrete in the volume of the outer mold corresponding to the bottom wall of the block in which process: - the outer mold is placed on the support plate, the inner core being suspended in the outer mold; - the outer mold is filled with concrete; the vertical packing means are actuated in the volume of the outer mold corresponding to the side walls of the block, the horizontal packing means are actuated in the volume of the outer mold corresponding to the bottom wall of the block.

This manufacturing process has the same advantages as the press presented above.

Preferably, the horizontal packing means is actuated after the vertical packing means. Thus, it pushes horizontally a volume of concrete that has been previously compacted vertically.

Preferably, the horizontal packing means and the vertical packing means are alternately actuated. This makes it possible to pack the concrete into the mold progressively, thus guaranteeing a homogeneous density of the walls of the mold.

More preferably, the outer mold is vibrated during its filling so as to improve the settlement of the concrete in said outer mold.

The invention will be better understood with the aid of the accompanying drawing in which: - Figure 1 shows a schematic sectional view of a dwelling whose sanitation pipes are connected to a junction box; - Figure 2 shows a perspective view of a connection box made with a block press according to a first embodiment of the invention; - Figure 3 shows a schematic sectional view of a block press according to a first embodiment of the invention for the manufacture of junction boxes as that of Figure 2; FIG. 4A represents a top view in transparency of the mold of the block press of FIG. 3, the means for horizontal packing of the mold being in the horizontal compacting position in the right part of the mold and in the filling position in the part. left of the mold; - Figure 4B shows a schematic sectional view of the mold of Figure 4A in the plane E-E; - Figure 4C shows a schematic sectional view of the mold of Figure 4 along the plane F-F, only a tamping pestle being shown on the right side; FIG. 5 represents a schematic sectional view in simplified perspective of the mold of FIG. 4A, the inner core of which is suspended; - Figure 6 shows a schematic sectional view of a mold according to a second embodiment of the invention, the inner core is beveled; and FIG. 7 represents a perspective and transparency view of the junction box of FIG. 2, with an additional stage and a removable cover.

With reference to FIG. 2, a junction box 10 is in the form of a parallelepipedal hollow concrete block comprising four lateral walls 11 and a bottom wall 12, the box 10 being open by its face opposite to the wall of FIG. In the description, the terms "upper" and "lower" are defined with respect to the junction box 10 of FIG. 2, the lower face of which is that of the bottom wall 12 and whose upper face is open.

Furthermore, the junction box and the different elements of the block press are oriented such that the side walls 11 of the junction box are vertical and that its bottom wall 12 is horizontal. Thus, the terms "horizontal", "vertical", "up", "down", "left", "right", "front" and "rear" are defined with respect to the positions of the parts and with reference to the axes represented on FIGS. 3, 4A, 4B, 4C and 5. Thus, the horizontal axis X is oriented from left to right, the depth axis Y is oriented from front to rear and the vertical axis Z is oriented from the bottom to the top. The notions of interior and exterior are taken in relation to the inside or the outside of the junction box or the mold making it possible to form it.

The side walls 11 of the junction box 10 comprise breakable zones 13 for connecting sanitation pipes to the internal volume of the junction box 10. These breakable zones 13 will be presented in detail later.

To manufacture the junction box 10 of FIG. 2, a block press 20, as represented in FIG. 3, is used, comprising a frame 24, a horizontal support plate 21 for a molding module 30 for simultaneous manufacture. of two junction boxes 10, a module 22 for filling the molding module 30 with a mixture of concrete in the pasty state and a vertical settlement module 23 arranged to vertically compact the concrete in the molding module 30 after it has been filled. . The block press 20 comprises demolding arms, not shown, connecting the molding module 30 to the frame 24 and which are arranged to move the molding module 30 vertically during the demolding operations, in order to demold the box formed by the press 20.

In this example, with reference to FIG. 4B, the molding module 30 comprises two elementary molds 30 ', 30 "each comprising an inner core 40 arranged to define the inner shape of a junction box 10, each elementary mold 30' , 30 "defining its external shape. An elemental mold is also referred to as the outer mold as opposed to the inner core. It goes without saying that the molding module 30 may comprise a single or a plurality of elementary molds 30 ', 30 ". When the molding module 30 has only one elementary mold, the molding module is considered as an elementary mold or outer mold, as such. The molding module 30 will be detailed later.

The horizontal plate 21, also known to those skilled in the art under the name board, is preferably in the form of a conveyor arranged to move the demolded connection boxes 10 from left to right, in a known manner. Referring to Figure 3, the support plate 21 is in this case a conveyor belt. The molding module 30 is supported, during molding, by the horizontal plate 21.

The module 22 for filling the molding module 30, also known to those skilled in the art under the designation filler drawer, is, for its part, in the form of a carriage arranged to translate horizontally relative to the frame 24 from left to right, and to pour into the volume of the molding module 30 a pasty mixture of concrete composed mainly of sand and aggregates agglomerated with a binder of Portland cement type known to those skilled in the art.

The vertical settlement module 23 is, for its part, in the form of a carriage arranged to translate vertically relative to the frame 24, from top to bottom, so as to compact the concrete vertically in the molding module 30 .

The vertical packing module 23 comprises at least one compaction pylon 25 arranged to translate vertically through the upper face (open) of the molding module 30 in order to vertically compact the concrete in the molding module 30. Such a block press 20 is in itself known to those skilled in the art unlike the molding module 30 which is the subject of the invention.

With reference to FIGS. 4A-4C, the molding module 30 is in the form of a parallelepiped opened by its upper 36 and lower 37 faces and comprising four vertical lateral walls 31, 32, 33, 34. With particular reference to FIG. 4B, the molding module 30 further comprises a partition wall 35 arranged to provide two elementary molds 30 ', 30 "in the molding module 30 for the manufacture of two junction boxes 10. In this example, the wall separation piece 35 is formed in the middle of the molding module 30 so as to define two elementary molds 30 ', 30 "of the same dimensions for the simultaneous manufacture of two identical junction boxes 10. The molding module 30 has a symmetry with respect to its partition wall 35, the elementary molds 30 ', 30 "being symmetrical to each other with respect to the partition wall 35. For the sake of clarity, only the Elemental mold 30 'is going to be detailed.

Still with reference to FIG. 4B, the elementary mold 30 'is generally in the form of a parallelepiped; it comprises a body opened by its upper 36 and lower 37 faces and comprising four lateral walls 31, 35, 33, 34. In the present case, the walls 31, 35, 33, 34 of the body extend between an upper horizontal plane PI and a lower horizontal plane P2 parallel to each other.

Referring to Figure 5 showing the mold 30 'with its core 40, the elementary mold 30' comprises an inner core 40, with a bottom wall 42, which is suspended in its interior. The inner core 40 is substantially in the form of a cube which is suspended in the interior volume of the elementary mold 30 'by support bars 39, passing through said core 40, well known to those skilled in the art. Referring to Figure 5, the support bars 39 pass through the inner core 40 and have a first end connected to the side wall 34 of the elementary mold 30 'and a second end connected to the side wall 35 of the elementary mold 30'. The core 40 comprises four side walls 43, an upper wall 41 and its bottom wall 42 or bottom wall 42.

In a horizontal plane (X, Y), with reference to FIG. 4A, the inner core 40 is centered in the elementary mold 30 'so that the distance between the side walls 43 of the inner core 40 and the side walls 31 , 35, 33, 34 of the elementary mold 30 'are substantially equal to define between them a volume corresponding to the side walls 11 of the junction box 10 to form. Thus, when the inner core 40 is centered in the elementary mold 30 ', the side walls 11 of the box 10 formed in the mold 30' have the same thickness.

In a vertical plane (Z, Y), with reference to FIG. 4B, the upper surface of the upper wall 41 of the inner core. 40 is coplanar with the open upper face 36 of the elementary mold 30 '. The bottom wall 42 of the inner core 40 (and more precisely the lower surface of the bottom wall 42) extends, for its part, away from the open bottom face 37 of the elementary mold 30 ', that is to say say at a distance from the lower horizontal plane P2 defined above; thus, said bottom wall 42 of the core 40 extends in a plane parallel to the plane of the lower face 37 of the elementary mold 30 and remote from it to define with it a volume corresponding to the bottom wall 12 of the connection box 10 to form.

In other words, once the core 40 placed in its elementary mold 30 ', there remains in said elementary mold 30' a volume between the side walls 43 of the core 40 and the side walls 31, 35, 33, 34 of the elementary mold 30 ' to form the side walls 11 of the junction box 10. Likewise, there remains in said elementary mold 30 'a volume between the bottom wall 42 of the core 40 and the lower face 37 of the elementary mold 30' to form the wall of the bottom 12 of the junction box 10; this last volume is in this case closed, on the lower side, by the horizontal plate 21.

In addition, once the core 40 is placed in its elementary mold 30 ', the upper face 36 of the elementary mold 30' is only partially opened due to the presence of the inner core 40. In other words, the open top surface 36 of the elementary mold 30 'with its core 40 is in the form of a rectangular peripheral ring 38 whose thickness corresponds to the distance between the core 40 and the elementary mold 30', that is to say at the thickness of the side walls 11 of the junction box 10 to be formed. This surface is designated "filling surface 38" because it corresponds to the filling surface of the elementary mold 30 'by the filling module 22 of the block press 20.

Preferably, the shape of the compacting pest 25 of the vertical settlement means 23 is adapted to correspond to the filling surface 38 of the molding module 30. In order to simultaneously tamp the two elementary molds 30 ', 30 ", the compacting pylon 25 is in the form of two distinct vertical parts which fit into the elementary molds 30, 30 'associated with their cores 40 during the vertical settlement, the horizontal surface of the lower end of each part of the pestle compaction 25 corresponding to the filling surface 38 of each of the elementary molds 30 ', 30 ". More specifically, each portion of the pestle 25 consists of a plurality of sectors which leave between them a passage for the fixing bars 39 of the inner core 40 to the outer mold 30 'during the vertical movement of the sectors of the pestle 25, in a known manner .

The elementary mold 30 'further includes horizontal packing means 50 which are provided at the side walls 31, 35, 33, 34 of the elementary mold 30'. The horizontal packing means 50 are in the form of two tamping piers 51 facing each other on the one side and the other side of the mold 30 'and respectively driven in horizontal translation by two jacks 53 in the elementary mold 30', to exert a force along a settlement axis Xt, parallel to the horizontal direction X. In this case, the drumsticks 51 are formed in the side walls, that is to say they form a movable extension. With reference to FIGS. 4A and 4C, the horizontal packing pestles 51 are respectively formed in the opposite lateral walls 31, 33 of the elementary mold 30 ', the tamping pestles 51 being identical.

A horizontal tamping pylon 51 is in the form of a parallelepiped bar extending along the axis Y and arranged to move in a reciprocating movement along the axis of settlement Xt.

Each horizontal packing drum 51 is formed at the lower vertical end of a side wall 31, 33 of the elementary mold 30 '. In addition, each tamping drum 51 has a length equal to the length of the side face 43 of the core 40 which faces the side wall 31, 33 of the elementary mold 30 'in which the tamping drum 51 is formed. Thus, the horizontal tamping drum 51 makes it possible to compact the concrete under the inner core without compacting the already vertically compacted concrete which is situated near the lateral walls 32, 34 perpendicular and adjacent to the lateral wall 31, 33 of the elementary mold 30 ' wherein the tamping pestle 51 is formed. This prevents excessive settlement of the concrete near said side walls 31, 33.

With reference to FIG. 4B, the vertical thickness of the tamping drum 51 corresponds to the distance between the bottom surface of the bottom wall 42 of the inner core 40 and the horizontal plane P2 corresponding to the lower face 37 of the elementary mold 30 ' , that is to say the thickness of the bottom wall 12 of the connection box 10 to be formed. This makes it possible to pack in a distributed and homogeneous manner the bottom wall of the box 10 to be formed.

With reference to FIG. 4, the tamping drum 51 is arranged to move between two extreme positions: a filling position, in which the tamping drum 51 extends entirely in the extension of the lateral wall 31, 33 in which it is arranged, without protruding into the interior volume of the mold 30 ', and a compacting position, in which the tamping drum 51 is protruding into the interior volume of the elementary mold 30' to horizontally compact the concrete which is there find.

The race of the tamping drum 51, defined between its filling and compacting positions, corresponds in this case to the distance between a side wall of the inner core 40 and the side wall 31, 33 of the elementary mold 30 'facing it, that is to say the thickness of a side wall 11 of the junction box 10 to be formed. In other words, in the filling position, the tamping drum 51 ensures the continuity of the flat lateral wall 31, 33 of the elementary mold 30 ', whereas in the compaction position, the inner end of the tamping drum 51 is at right of the side wall 43 of the inner core 40 facing the side wall 31, 33 of the elementary mold 30 'in which the tamping pylon 51 is formed.

In order to preserve a compact mold, in particular laterally with respect to the conveying direction X of the horizontal plate 21, the horizontal tamping drum 51 is driven in translation by a jack 53 which is offset on a lateral wall 32, 34 of the elementary mold 30 'which is parallel to the axis of settlement Xt and which is perpendicular and adjacent to the side wall 31,33 in which the tamping pylon 51 is formed. The jack 53 comprises a rod driven in translation by a hydraulic piston. The jack 53 is connected to the tamping drum 51 by a support arm 52 having an L shape. One end of the L, whose arm 52 has the shape, is connected to the rod of the jack 53 while the other end is connected to tamping pestle 51.

It has been described here a hydraulic cylinder but it goes without saying that other types of actuators could also be suitable such as a pneumatic cylinder or cams moved electrically.

Preferably, for each elementary mold 30 ', 30 ", there are provided two identical tamping pencils 51 arranged to translate according to compaction law Xt in a back and forth motion. Preferably, the tamping pestles 51 are synchronized so that they are both at the same time in the compacting / filling position. This makes it easier to obtain junction boxes whose bottom walls have a homogeneous density.

With reference to FIG. 4A, the jacks 53 of the tamping pencils 51 of the elementary mold 30 'are formed in one and the same side wall 34 of the elementary mold 30'. Compared to a mold in which the cylinders are formed in two different side walls, this advantageously optimizes the space within the molding module 30 and reduce the mold dimensions. It goes without saying that the cylinders 53 could also be arranged in any side wall of the elementary mold 30 '.

The method of manufacturing a junction box 10 by means of a block press 20 and a molding module 30 according to the invention will now be presented. The manufacturing process will be explained for only one box formed by an elementary mold 30 '.

As shown in FIG. 3, the molding module 30 is placed on the support plate 21 of the block press 20 so that the mold 30 'is closed by its lower face 32 by the support plate 21. mold 30 'and its inner core 40 define between them a volume corresponding to the side walls 11 of the junction box 10 to form, the inner core 40 being arranged to extend away from the plate 21 of the press 20 to define with it a volume corresponding to the bottom wall 12 of the connection box 10 to be formed.

The filling module 22 of the block press 20, filled with concrete in pasty form, moves in horizontal translation, to the right, to be placed above the mold 30 '. The filling module 22 empties its contents through the upper face 36 of the mold, the concrete entering the mold 30 'by the filling surface 38 shown in FIG. 4A.

Under the effect of gravity, the concrete spreads in the mold 30 'heterogeneously, the volume corresponding to the side walls 11 of the junction box 10 being relatively dense while the volume corresponding to the bottom wall 12 of the junction box 10 is less dense. After filling the mold 30 ', the empty filling module 22 is moved to the left so as to make the upper face 36 of the mold 30' accessible for the vertical settlement module 23.

The vertical settlement means 23 are actuated and move vertically downwards in a back-and-forth movement, the compacting pestles 25 pushing the concrete into the volume corresponding to the side walls 11 of the junction box 10. the effect of compression, the concrete moves with difficulty in the volume corresponding to the bottom wall 12 of the junction box 10, the volume corresponding to the side walls 11 of the junction box 10 being dense while the volume corresponding to the bottom wall 12 of the junction box 10 has a heterogeneous density.

The vertical packing means 23 are stopped and the horizontal packing means 50 of the mold 30 'are actuated in the volume corresponding to the bottom wall 12 of the connection box 10, the concrete being located in the lower part of the volume corresponding to the side walls 11 of the junction box 10 being then moved by the tamping piers 51 towards the center of the mold 30 ', under the inner core 40, along the axis of settlement Xt, in the volume corresponding to the bottom wall 12 of the junction box 10. Thus, the volume corresponding to the bottom wall 12 of the junction box 10 is compacted.

Preferably, the vertical settlement means 23 are then actuated again so as to densify the concrete in the volume corresponding to the side walls 11 of the connection box 10, in particular in the lower part of said volume which has been displaced by the horizontal packing means 50. Depending on the desired density, the duration of the horizontal and vertical settlement cycles and the number of cycles are adapted, the horizontal and vertical settlement cycles preferably being alternated.

More preferably, the molding module 30 is vibrated during its filling by the filling module in order to improve the distribution of the concrete in the mold 30 '.

According to a second embodiment of the press of the invention, with reference to FIG. 6, all the other elements being otherwise identical or comparable, the bottom wall 42 of the inner core 40 is bevelled so that the distance between the lower surface of the bottom wall 42 of the core 40 and the support plate 21 is decreasing as the side walls 31, 35 are moved towards the inside of the mold 30 ', 34, 33 of the mold 30 'along the axis of settlement Xt.

In the present case, with reference to FIG. 6 representing an elementary mold 30 'with its packing pestles 51 in the filling position, the bottom wall 42 of the inner core 40 comprises two adjacent oblique surfaces 42a, 42b separated by a median ridge. extending in the direction Y, orthogonal to the settlement axis Xt, the slopes of said oblique portions 42a, 42b for guiding the concrete in the volume defining the bottom wall 12 of the box 10 so as to increase the density thereof . A beveled core makes it possible to increase the density of the bottom wall 12 during horizontal settlement, since their effect is to compress the concrete pushed in the direction of the volume reduction.

After tamping, the mold 30 'is moved vertically relative to the frame 24 of the block press 20 by the demolding arms connecting the elementary mold 30' to the frame 24. The displacement of the elementary mold 30 'causes the mold to be demolded. 10, the concrete is dense and wet, the demolded box 10 remaining on the support plate 21. After total release of the elementary mold 30 ', the support plate 21, here a treadmill, is moved to cause the demoulded connection boxes 10 to a drying zone. After drying, the junction boxes 10 are packaged on pallets for distribution.

Thanks to the block press and its molding module 30, it is then possible to immediately manufacture new junction boxes. To do this, the demolding arms deposit the molding module 30 on the support plate 21, the latter then being in position to be filled again by the filling module 22 of the block press 20. It is thus possible to renew the previous steps to manufacture junction boxes whose bottom wall has a uniform density. The manufacturing is fully automated.

According to another characteristic of the invention, each elementary mold 30 'of the molding module 30 comprises punching means arranged to punch the side walls 11 of the junction box 10 so as to form breakable zones 13 in said side walls 11 as shown in Figure 2.

With reference to FIGS. 4B, 4C, the punching means 60 comprise a punch 62 formed in a side wall 31, 35, 33, 34 of the elementary mold 30 'and arranged to translate towards the inside of said mold 30' so as to punching a side wall 11 of the junction box 10 orthogonal to the plane in which said side wall 11 extends. The punch 62 is actuated by a jack 61 which is formed in a side wall 31, 35, 33, 34 of the mold elementary 30 ', preferably in the same wall of the mold 30' in which is formed the punch 62.

The punch 62 has a circular arc shape extending around a center angle strictly less than 360 ° and preferably greater than 340 °. During the punching, the punch 62 translates inwardly of the elementary mold 30 'and penetrates the side wall 11 of the connection box 10 not yet dry, without opening on the other side of this wall 11. After punching, the punch 62 is translated to the outside of said mold 30 'to enter the inside of the side wall of the elementary mold 30' in which it is formed.

The punched zone of the side wall 11 of the junction box 10 is in the form of an almost complete circular arc except for an angular portion, forming a support bead 14 observable in FIG. 6, connecting the parts of the wall located inside and outside the circular arc whose punch 62 has the shape.

Thus, after demolding, the wall portion located inside the arc is retained by the support cord 14, thus avoiding collapse during the drying of the connection box 10. The part of wall located inside the arc is designated breakable zone 13 of the side wall 11. The punching module is arranged to punch the side wall so that the support cord extends to the lower side of the the arc of the circle, that is to say on the side of the horizontal support plate. After unmolding, the support cord makes it possible to support the breakable part of the lateral wall (situated inside the arc of a circle) in order to prevent the latter from collapsing, due to its weight, during the drying, on the unscored part of the side wall (located outside the arc).

Thanks to the breakable zone 13, an operator can easily create an opening in a side wall 11 by giving, for example, a hammer blow in the breakable zone 13 so as to yield the side wall 11 with its support cord 14. Prior punching of the side wall 11 allows for a clear circular opening, without excessive effort. Moreover, the shape of the punch 62 is adapted so that the circular opening made in the side wall 11 of the box 10 has a standard diameter for receiving a standard elastomeric sealing gasket, preferably of the Forsheda type. the company Trelleborg, known to those skilled in the art. This makes it possible to connect a sanitization pipe of standard size, adapted to the seal, to the junction box 10.

With reference to FIG. 7, a junction box 10 with a dense bottom can be produced which can be used either directly or with at least one junction box stage 10E, fitting on the top of the junction box. 10 connection, and a removable closure cover 14. The 10E junction box stage has no bottom and can be manufactured by a block press with a traditional mold.

Claims (13)

A block press (20) for manufacturing at least one hollow concrete block (10) with side walls (11) and a bottom wall (12), the press (20) comprising a horizontal plate (21) ) of the block (10) during its manufacture, an outer mold (30) with an inner core (40) arranged to define between them a volume corresponding to the side walls (11) of the block (10), the inner core (40) being arranged to extend away from the plate (21) to define with it a volume corresponding to the bottom wall (12) of the block (10), the press (20) further comprising means (23). vertical settlement of the concrete in the volume corresponding to the side walls (11) of the block (10) and the outer mold (30) comprising means (50) for horizontal settlement of the concrete in the volume of the outer mold corresponding to the bottom wall (12) of the block (10). 2. Press according to claim 1, wherein the means (50) for horizontal settlement comprise at least one tamping pestle (51) actuated by a jack (53), the pestle (51) exerting a compressive force along an axis of settlement (Xt). 3. Press according to claim 2, wherein the tamping pylon (51) is arranged to be drivable in horizontal translation, preferably in a back and forth motion. 4. Press according to one of claims 2 to 3, wherein, the outer mold (30) having side walls (31, 32, 33, 34), the tamping pestle (51) is in the form of a horizontal arm arranged near an end of a side wall (31, 33) of the outer mold (30), preferably at the lower end of said side wall (31, 33). 5. Press according to one of claims 2 to 4, wherein the tamping pestle (51) has a vertical thickness equal to a thickness of the bottom wall (12) of the block (10) to be manufactured. 6. Press according to one of claims 2 to 5, wherein the outer mold (30) comprises two tamping pestles (51) mounted vis-a-vis on both sides of the outer mold (30) and ordered so as to exert opposite direction compressive forces directed inwardly of the outer mold (30). 7. Press according to one of claims 1 to 6 wherein the inner core (40) and the support plate (21) are arranged so that the distance between them is decreasing as one moves away inwardly of the sidewalls (11) of the outer mold (30) along said settlement direction (Xt). 8. Press according to one of claims 1 to 7, comprising a punching module (60) arranged for punching at least one side wall (11) of the block (10), the punching module (60) comprising a punch (62). ) having the shape of an arc extending preferably around a center angle strictly less than 360 ° and preferably greater than 340 °. Mold for manufacturing at least one hollow concrete block (10) with side walls (11) and a bottom wall (12) for use in a block press (20), comprising: a body having side walls (31, 32, 33, 34) extending between an upper face (PI) and a lower face (P2), the body being open at its upper and lower faces; and means (50) for horizontally compacting the concrete in a volume corresponding to the bottom wall (12) of the block. The mold of claim 9, wherein the mold (30) has an inner core (40) having a bottom (42), the core (40) being suspended in the mold body (30) so as to define between them a volume corresponding to the side walls (31, 32, 33, 34) of the block and under the bottom (42) of the core (40) a volume corresponding to the bottom wall (12) of the block. A method of manufacturing a block press (20) of at least one hollow concrete block (10) with side walls (11) and a bottom wall (12), the block press (20) comprising: - a horizontal plate (21) for supporting the block (10) during its manufacture, an outer mold (30) with an inner core (40) arranged to define between them a volume corresponding to the side walls (11) of the block ( 10), the inner core (40) being arranged to extend away from the plate (21) to define with it a volume corresponding to the bottom wall (12) of the block (10), the press (20) comprising elsewhere means (23) vertical settlement of the concrete in the volume corresponding to the side walls (11) of the block (10) and the outer mold (30) comprising means (50) of horizontal settlement of the concrete in the volume of the outer mold corresponding to the bottom wall (12) of the block (10), in which process: - the outer mold (30) is placed on the support plate (21), the inner core (40) being suspended in the outer mold (30), - the outer mold (30) is filled with concrete; the vertical settlement means (23) are actuated in the volume of the outer mold corresponding to the side walls (11) of the block (10), and the horizontal settlement means (50) are actuated in the volume of the outer mold corresponding to the wall; bottom (12) of the block (10). 12. The method of claim 11, wherein is actuated alternately means (50) of horizontal settlement and the means (23) of vertical settlement. 13. Method according to one of claims 11 to 12, wherein the outer mold (30) is vibrated during its filling so as to improve the settlement of the concrete in said outer mold (30).