MC336A1 - Continuous manufacture of profiled parts such as sheets, plates, tubes, etc., having a lacunar structure, and in particular reticulated - Google Patents

Description

PATENT FOR INVENTION

Continuous manufacturing of profiled parts such as sheets, plates, tubes, etc., exhibiting a gap structure, and in particular a reticulated one.

RICAL Company

The present invention relates to a method and a machine for the continuous manufacture of profiled parts such as sheets, plates, tubes, etc., having a void structure, in particular reticulated (mesh, trellis, net, fabric, etc...), in particular in synthetic material.

A process and a machine are already known for the continuous production of sheets or tubes with a reticulated structure. They employ the continuous extrusion of the material through two sets of dies, which are moved relative to each other in a direction transverse to the extrusion direction. The two sets of dies simultaneously produce two independent, juxtaposed sheets of extruded yarns. The yarns of one sheet are locally bonded by spontaneous adhesion to those of the other at each coincidence of the dies of one set with those of the other, thus forming the "nodes" of the network. Consequently, the network can never have a uniform thickness, since its "nodes" are only slightly less than twice the thickness of each extruded yarn, which presents disadvantages for certain applications (fishing nets). Furthermore, the production of the two sets of dies is very expensive.

The present invention makes it possible to manufacture sheets, plates or tubes under much more economical conditions

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of reticulated and more generally lacunar structure, which can also offer the advantage of having a uniform thickness,

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including at the crossing points of the bars, strips or wires that make up the network (no extra thickness at the "nodes" of said network); the reduction in the cost price of networks manufactured according to the invention results in particular from the use of simpler means to manufacture them.

More generally, the present invention makes it possible to manufacture very economically profiled parts of any cross-section, presenting a lacunar structure.

The manufacturing process according to the invention is characterized by the fact that it consists of continuously flowing the liquid or pasty material along a sheet, having the cross-section of the profiled part to be manufactured, creating in this sheet the necessary gaps by preventing the flow of the material at the corresponding places, and then immediately solidifying the gap-filled sheet thus formed.

The machine for implementing the process according to the invention is characterized by the fact that it essentially comprises at least one die for extruding the material according to the profile to be obtained, as well as means for preventing at least temporarily the material from exiting said die at the places corresponding to the necessary gaps, and for solidifying it as soon as it exits its die.

As an example, several forms of embodiment of the machine allowing the process according to the invention to be implemented have been described below and schematically illustrated in the attached drawing.

Figures 1 and 2 respectively represent two different phases of the operation of a machine enabling the continuous production of plates or sheets of reticulated structure with rectangular or square meshes.

Figures 3 and 4 represent, respectively in bottom view and in section along line IV-IV of figure 3, a variant of the machine of figures 1 and 2.

Figures 5 to 8 illustrate an improvement to the machine shown schematically in figures 3 and 4.

Figures 9 and 10 schematically represent two different phases of the operation of a machine enabling the continuous production of sheets with a reticulated structure and diamond-shaped mesh.

Figure 11 shows a bottom view of a machine for the continuous production of tubes with reticulated structures with rectangular or square meshes.

Figure 12 shows in cross-section by a diametral plane an embodiment comprising a fixed cylindrical die, around which a concentric annular die can slide axially.

Figure 13 is a perspective view from below of the two dies of the machine illustrated in Figure 12.

Figure 14 represents a variant of the machine in figures 12 and 13 in cross-section by a diametrical plane.

Figures 15 to 17 represent another embodiment, allowing the extrusion of a lacunar structure with a rectangular cross-section.

Figures 18 and 19 represent two different phases of the operation of a machine according to the invention with two extrusion dies.

Figure 20 represents a wire mesh produced using the machine shown in Figures 18 and 19.

Figures 21 and £3 represent in cross-section two embodiments of a machine according to figures 18 and 19.

Figures 22 and 24 represent a wire mesh frame and a packaging box made of synthetic material, which can be manufactured respectively using the machines, figures 21 and 23.

Figures 25 and 26 respectively represent, in cross-section and in section along line XXVI-XXVI of Figure 25, another embodiment of the nschine of the figures

Figures 27 and 28 illustrate two different phases of operation of another embodiment of the machine according to the invention, with two extrusion dies.

In these various figures, only the parts absolutely essential to understanding the principle of the invention have been represented; the parts not shown are known and their combination with those shown presents no particular technical difficulty.

The embodiment schematically represented in Figures 1 and 2 essentially comprises a machine for extruding the material into sheets, of which there are many well-known types, each adapted to the nature of the extrudable material used. The figure shows almost exclusively the flat die 1 with which machines of this type are equipped, and into which the material 2 is brought in a physical state suitable for extrusion. Below the outlet 1* of the flat die 1, and in its immediate vicinity, is arranged, in a horizontal plane, that is to say perpendicular to the direction of flow of the material out of said die 1, a comb 3, provided with regular teeth 3', of a straight shape in the illustrated example. This comb 3 is positioned parallel to the outlet 1' of the flat die 1, so that its teeth 3* are perpendicular to the sheet material exiting said die 1. The comb 3 is mounted so as to be able to slide perpendicularly to the die 1, notably by means of guide elements 4 at its ends; positive control elements such as the connecting rod 5 allow the comb 3 to be moved by sliding between a first position, where its teeth partially obstruct the outlet 1' of the flat die 1 (Fig. 1), and a second position, where its teeth 3' are fully extended relative to said outlet 1' (Fig. 2). Means, not shown but known, are provided for acting on the positive control elements such as 5 so as to alternately move the comb 3 from one to the other of its two positions defined above; these known means may consist, for example, of cams, connecting rod-lever systems

y velle, etc.*. controlled by a suitable motive power source.

When the comb 3 is in its first position shown in Figure 1, the material exits the flat die 1 not in the form of a continuous sheet, but in the form of linear elements 6, which are vertical in the illustrated example, and which flow through the gaps between the teeth 3' of the comb 3,

each of the said teeth 3* preventing the flow of material over its entire width, resulting in the formation of gaps 7 separating the linear elements 6.

I. When comb 3 occupies its second position

As shown in Figure 2, the outlet 1' of die 1 is thus completely unobstructed, and the material flows uniformly along the entire length of said die, forming one of the linear elements 8, which are horizontal in the illustrated example. It can be seen that the intersection of the vertical linear elements 6 and horizontal linear elements 8 gives

to the sheet emerging from the die 1 a reticulated structure with rectangular or square meshes, to which the solid state is conferred immediately upon its formation, i.e. below the comb 3, by appropriate means known and adapted to the nature of the extrudable material used and not shown. The thickness of the vertical linear elements 6 is close to the width of each of the intervals between the teeth 3', while the width of the meshes 7 corresponds approximately to the width of said teeth 3'. The thickness of the horizontal linear elements 8 and the height of the meshes 7, on the other hand, depend on the extrusion speed of the material in the die 1, and on the other hand, on the time intervals during which the outlet 11 of the flat die 1 is, respectively, totally unobstructed or partially obstructed by the teeth 3' of the comb 3; Insofar as the sheet extrusion speed can be kept constant, the ratio between the successive time intervals during which the teeth of the comb 3 partially obstruct the outlet 1 of the flat die 1, and those during which said teeth 3 are clear, is preferably chosen to be equal to the ratio between the height of the meshes 7 and the thickness

*

Depending on the thicknesses given to the linear elements 6 and 8 and the degree of flexibility they retain after solidification of the extruded material, these linear elements can be considered as bars, the resulting network then being a mesh or lattice, or as wires, the resulting network then exhibiting the flexibility of a fabric, from which it differs notably in that it is made from a single piece, produced without welding or gluing. It should be noted that the network whose manufacture has just been described has, at each of the intersection points of its linear elements 6 and 8, a thickness equal to that of said linear elements; this characteristic clearly distinguishes it from networks that are manufactured in a known manner, such that their intersection points are formed by the joining of at least two independent linear elements, and in which the thickness of the intersection points is generally slightly less than twice that of each of the constituent linear elements.

A tightly woven mesh network can be manufactured in the manner just described from any extrudable material, including:

1°/Synthetic materials, in particular thermoplastics and thermosetting materials, as well as natural and synthetic rubbers; in the first case, the thermoplastic material is heated in the extrusion machine until it reaches its softening temperature and then it is cooled rapidly below the comb 3, for example by immersion in a liquid, by the action of a cold air current, etc.; The flat die 1 of the machine and the comb 3 are then preferably brought to the extrusion temperature, by known means, which it is unnecessary to describe; the comb 3 is then preferably made of a metal that is a good conductor of heat.

1°/ Materials that can be spun in the wet state, such as viscose, which can be extruded at mid, their hardening below the comb 3 being obtained by immersion in, or spraying with, a suitable product.

3°/ of the glass

4°/ Metals and their alloys in a pasty or molten state; the flat die 1 can be replaced in this case by a rolling mill train.

The variant shown schematically in Figures 3 and 4 is equipped with a double comb 3, which is formed by two combs 3 and 32, identical to each other and to the single comb 3 of the embodiment shown in Figures 1 and 2; the two identical combs 3 and 32 are rigidly joined together in such a way that the ends of all the teeth of one are at the same distance j, opposite the ends of the teeth of the other.

this distance being at least equal to the width ,b of the flat die; In the illustrated example, the two combs 3^ and 3^ are made by machining a single metal plate 3. The comb system 3 can slide perpendicularly to the flat die 1 in guide members 4, 4', between the following two extreme positions: a first position in which the teeth 3'^ of the comb 3^ partially obstruct the outlet 1* of the die 1, as shown in figure 4, in cross-section by a plane passing between two consecutive teeth of said comb; a second extreme position, symmetrical to the previous one with respect to the longitudinal plane of symmetry of the flat die 1, and in which it is the teeth 3'2 of the comb 3g that partially obstruct the outlet 1' of the die 1; Between these two extreme positions, the comb system 3 passes through an intermediate position, shown in Figure 3, in which the longitudinal planes of symmetry of the comb system 3 and the flat die 1 coincide. The outlet 1' of said flat die is then completely unobstructed, since its width b is at most equal to the interval a between the corresponding teeth of the two combs 3 and 32. Known means, acting on the positive control member 5, periodically move the comb system 3 from one of its two extreme positions to the other, passing through its intermediate position. The principle of forming the grit using the double comb 3 is the same as that of forming it using the single comb 3 of Figures 1 and 2, the teeth of each of the two half

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°1 and 3^ of said double comb working simply alternately to form the meshes of said network.

The device described using figures 3 and 4 has the following drawback: when the teeth 3'^, 3'2 of the double comb 3 are completely obliterated relative to the outlet of the flat die 1, the material exiting the latter not only passes through the gaps existing between the pairs of opposite teeth of the two combs 3^ and 3^, but it also tends to pass through the gaps existing between the teeth of the same comb; it results in particular that the sheet of lacunar structure obtained by this device has excess thickness at the points of intersection of its linear elements 6 and 8. To overcome this drawback, the variant illustrated in figures 5 to 8 includes a plate |3, shown in elevation in figure 6, which has a median slot 13* of length and width at least equal to those of the outlet of the die, and one face of which supports pieces intended to be intercalated between the teeth of the comb system; In the illustrated example, these pieces are substantially in the shape of parallelepipeds 14; they each have a length corresponding substantially to the interval between the two teeth of the comb 3 between which they must be intercalated respectively, and a depth less than the depth of said tooth interval; this is visible in particular in figure 5 which is a top view of the plate 13 and the double comb 3 placed on it so that the said pieces 14 are intercalated between its teeth 3', 3'2. We see in figure 7 that the said pieces 14 obstruct the intervals between the teeth of the two combs 3, 3'2 when these are erased with respect to the exit of the die 1, so as to prevent the material from passing through these intervals; as the plate 13 and the pieces 14 which it supports are fixed with respect to said die, these latter pieces never obstruct the exit of the die; They also do not prevent the movement of the double comb 3 relative to the said die, as can be seen in particular in Figure 8. As an alternative, it is also possible to remove parts 14 and retain only

that the plate -13, having its median slot 13', of width at least equal to the width b, of the outlet of the die 1, said plate 13 being simply applied against the face of the double comb 3 opposite to the outlet of the die 1.

The machine for manufacturing a reticulated structure sheet with diamond meshes, which is illustrated very schematically in figures 9 and 10 (on which the sheet extrusion die has not been shown, for reasons of clarity), is also equipped with a double comb 3, formed of two identical combs 3^,32, which are rigidly assembled together so that the ends of all the teeth of one come to be intercalated in the middle of the teeth of the other, at the same distance from the bottoms of these teeth; it can be seen in particular in the figures that the ends of the teeth 3*2 of the comb 32 all come at the same distance c_ from the bottoms of the intervals between the consecutive teeth 3'.j of the comb 3^; the distance c, is chosen to be at least equal to the width of the outlet of the flat die (b in figures 3 and 4).

In the illustrated example, the two combs 3^, 3^ are made by machining the same metal plate 3 which is mounted so as to be able to slide perpendicularly to the flat die, not shown, between two extreme positions, symmetrical with respect to the longitudinal plane of symmetry of the flat die, and one of which is shown in figure 9; each of these two extreme positions of the comb system 3 is such that the bottoms of the teeth of comb 3^ or comb 3^ are then substantially opposite the exit of the flat die (1* in figures 3 and 4), so that said exit is then only partially obstructed by the bases of the teeth of the other comb 32 or 3^;

Between these extreme positions, the comb system 3 passes through intermediate positions, in which the outlet of the flat die is partially obstructed by both the teeth 3'1 of the comb 31 and those 3'2 of the comb 32. In the intermediate position corresponding to Figure 10, the material can only flow from the die (the trace of which on the diagram of the comb system 3 has been represented by the dashed line 9) on either side of each

teeth of the two combs 3^, 3^; there is then formation of the threads 10, 10* which constitute the sides of the lozenge meshes" In each of the extreme positions of the comb system 3 (fig. 9), the material can on the contrary only exit the flat die in the intervals remaining between each of the teeth of one of the combs and the bottom of the corresponding tooth interval of the other comb; then half the number of wire elements 11 are formed. The wire elements 10 are formed simultaneously in the intermediate positions, and, due to the continuity of the process, these wire elements 11 constitute crossing points of the wire elements 10, from which results the diamond mesh structure which is illustrated 5. It corresponds to the case where the wire elements 11 are much shorter than the wire elements 10, that is to say, the case where the comb system 3 remains in either of its two extreme positions for time intervals much shorter than those required to pass from one to the other of said extreme positions; By keeping the comb system 3 in either of its two extreme positions for longer intervals of time, it is possible to obtain wire elements 11 whose length approaches that of the wire elements 10, the resulting network then having hexagonal meshes. It should be emphasized that the wire elements 11 that constitute the crossing points of the lozenge-shaped network in Figures 9 and 10 are single wires and do not result from the juxtaposition and spontaneous bonding of two wires, as in the previously mentioned known process; this is particularly evident in the case of a hexagonal network according to the invention, where each of the wire elements 11 constitutes one side of a hexagonal mesh and has exactly the same thickness as the wires 10 constituting the other sides of said mesh. By giving the teeth of the combs 3 and 3, particularly their tips, which are preferably pointed, and the bottoms of their intervals, which are preferably rounded, appropriate shapes and dimensions, it is possible to ensure that the wire elements 10 and 11 have identical or different cross-sections; it is therefore possible to thus eventually give the wire elements 11 constituting the points of

crossing, a section smaller than that of the 10 wire elements

II

forming the sides of the diamond-shaped meshes, whereas this is strictly impossible by the known process mentioned previously.

The machine for manufacturing a reticulated tube with rectangular or square meshes, which is very schematically represented in view from below in Figure 11, essentially comprises a die of elongated rectangular shape, the outlet of which has the same width b on all four sides, and, below this die, and in its immediate vicinity, a system of combs 3, consisting of two combs 31, 32, preferably identical to each other and rigidly assembled one with the other in such a way that the ends of the teeth 3'1 of comb 31 are separated from those of the teeth 3'2 of comb 31 by an interval a at least equal to the width b of the outlet of the die 1; in the illustrated example, the two combs 31 and 32 are made by machining a single metal plate 3, which is mounted so as to be able to slide perpendicularly to the two long sides 11 of the outlet of the rectangular die,

thanks to guide elements, not shown; this sliding takes place in a plane parallel and practically tangent to that of the exit of the rectangular die, between two extreme positions, one of which is illustrated in figure 11, and which are symmetrical with respect to the plane of symmetry of the elongated rectangular die 1;

In each of these two extreme positions, the teeth of one of the two combs (those 3' of 3' in Figure 11) partially obstruct the outlet of one of the long sides of the die (1' in Figure 11), while the outlet of the other long side of said die (1' in Figure 11) is completely unobstructed; in each of these extreme positions of the comb system 3, one of the long sides of the die (1) thus forms vertical linear elements (such as 6 in Figure 1), while the other long side (1') simultaneously forms a single horizontal linear element (such as 8 in Figure 1). The notches 12, 12' provided in the comb system 3 at the level of the interval a between the ends of its two sets of teeth 3',

.3*2 so as to unmask areas continuously vanauios u«s

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two small sides 1g, 1^ of the die, respectively ensure the continuous formation of a linear element joining the two halves of the network which are manufactured respectively by the teeth of the two combs 31, 32.

The tubular network of rectangular cross-section thus obtained can be deformed, possibly before solidification, for example using a template in order to form a tubular network of any cross-section, possibly circular.

Several tubular networks can be manufactured simultaneously using a single rectangular die, to which several flounder combs are attached, placed side by side*

The process and machine according to the invention make it possible to produce sheets and tubes of reticulated structure with meshes of very diverse types, not only rectangular, square, lozenge or hexagonal as previously described, but also of much more complex shapes; the same process also makes it possible to produce sheets and tubes of lacunar structure, presenting for example designs, analogous to those of embroidery;.

By feeding the process simultaneously with differently colored materials, it is possible to obtain sheets and tobes with parallel multicolored bands.

The comb system associated, according to the invention, with the die of the sheet extrusion machine, must obviously be adapted to the type of mesh of the network to be produced, as well as the movements that must be imparted to this comb system; the expression "comb system" designates not only one or more combs rigidly assembled with each other, as previously described, but it can also designate, within the scope of the present invention, several combs, possibly of different structures, and capable of receiving independent movements relative to the die outlet, in particular for the purpose of producing networks with complex structures.

Figures 12 «t.ii. "... HAS

the invention, for extruding material into tubes, limited to the parts by which it differs from known machines of the same kind; it comprises a fixed die 21 having the form of a solid of revolution about the axis 22; its lower part comprises a ground conical annular surface 23, diverging downwards; an annular piece 24 attached to said die 21, in particular at 24', delimits with the ground surface 23 an annular extrusion channel 25, which descends in the axifuge direction, and whose upper annular inlet is fed by a distribution chamber also annular 26, which, in the illustrated example, is constituted by a groove made in the die 21, above the ground surface 23, said groove being closed on its periphery by the annular piece 24; the material to be extruded is brought, in a suitable physical state, through the upper end of a channel 27, arranged axially in the part of the die 21 located above the distribution chamber 26; radial channels 28 connect the axial channel 27 with the annular chamber 26, to bring the material to be extruded there. A second movable die 29 is constituted by a ring mounted around the lower end of the fixed die 21, above the lower edge of its ground surface 23, so as to be able to slide freely around the ring 24, attached to said die 21; in the illustrated example, the movable die 29 is integral with a ring 29' to which it is fixed, for example by bolts 30, and which can slide around the middle and upper parts of the fixed die 21, also in the direction of the axis 2; The lower end of the moving die 29 has a ground annular surface 23', through which said die 29 can make watertight contact with the ground surface 23 of the fixed die 21, or at least with its lower edge; in the ground surface 23' of the die 29 are formed radial grooves 31, or channels with an open cross-section on said ground surface. A heating sleeve 46, consisting for example of a wound electrical resistance, is fitted around the moving die 29 and the ring 29' attached to it, so as to heat said die and, by thermal conduction, also the fixed die 21, to a

temperature close to the extrusion temperature of the material in the case where the latter is higher than the ambient temperature. The machine further includes means for periodically moving the movable die 29 and the fixed ring 29' attached to it, by sliding around the fixed die 21, in the direction of the axis 22, from a position in which the ground surface 23' of said die 29 is in contact with the corresponding ground surface 23 of the die 21, to another position, higher than the previous one in the illustrated example, and in which the ground surfaces 23 and 23' of the two dies 21 and 29 are sufficiently separated to completely clear the outlet of the annular channel 25.

The manufacture of a rectangular mesh tube using the extrusion machine just described takes place in the following way; each time the two dies 21 and 29 are in contact with each other by their ground surfaces 23, 23', so that the outlet of the annular channel 25 is locally obstructed by the intervals between the transverse channels 31 of the die 29, the material supplied by the distribution chamber 26 is extruded exclusively through said transverse channels 31, forming as many linear elements, such as bars, strips, wires, etc., according to the dimensions of the sections of these linear elements, and consequently of the sections of the transverse channels 31; under the effect of gravity, these different linear elements exiting the transverse channels 25 form a sheet of parallel longitudinal elements 32, 32', presenting a closed section. Conversely, whenever the ground surfaces 23, 23' of the dies 21 and 29 are sufficiently separated from each other, by raising said die 29, so that the outlet of the annular channel 25 is completely unobstructed, the material is extruded through said channel 25 in the form of an annular element 33, transverse to the elements

9

parallel linear elements 32, 32' j this transverse linear element 33 is welded to the longitudinal linear elements 32, 32' in their paints

in the vicinity of its exit; thanks to the periodic formation of a linear transverse element such as 33 we obtain a tube with rectangular meshes T which, because its meshes are delimited both by longitudinal elements 32-32* and by transverse elements 33, exhibits remarkable dimensional stability in its two longitudinal and transverse directions.

The extruded tube T is received immediately below the outlet of the annular channel 25 by a template disc 34, which is fixed, for example, by a screw 35 to the lower end of the a

die 21; by giving this template 35 a shape and/or dimensions different from those of the section of the tube T at the exit of the annular channel 25, it is possible, by taking advantage of the residual plasticity of the extruded material before its solidification, to modify the shape and possibly enlarge or reduce the section of the tube T; it is also possible to modify the length of the extruded tube T before solidification, for example by exerting tensile forces on its longitudinal elements: 32, 32', in particular by loading them with weights.

The means necessary for the solidification of the T tube, which must be adapted to the nature of the extruded material, have not been shown in figures 12 and 13 because they are well known.

The machine just described can be easily modified to obtain tubes of lacunar structure having longitudinal parallel bands of various colours, and possibly of various widths; it is enough to subdivide the annular distribution chamber 26 into a corresponding number of compartments; each supplied by conduits, such as 27 and 28, independent of each other, with material to be extruded of various colours.

Since the channels 31 with which the die 29 is provided have their transverse section open, and since the ground surface 23' is preferably brought, when said die 29 occupies its upper position, into the extension of the upper wall of the annular channel 25, formed by the part 24, the material extruded by said *

1*

that there is no interruption in the formation of the longitudinal linear elements 32-32' during the formation of each of the annual elements

/

cross areas 33; in other words, at each of the nodes of its meshes, the tube made using the die illustrated in figures 12 and 13 has a cross section whose area is close to the sum of the cross sections of the linear elements respectively longitudinal and transverse which intersect at this node; the formation of the longitudinal elements 32-32' can, on the other hand, be interrupted during the formation of each of the transverse elements 33, by means of appropriate means, consisting for example of a ring 36 which comes to close the outlets of the transverse channels 31 of the die 29 when the latter is in the high position; this auxiliary arrangement makes it possible to obtain a tube of uniform thickness including i5 at the nodes of its meshes.

In the illustrated example, the width of the auxiliary channel 25 is determined by the distance between the lower edge of the part 24 and the ground surface 23 of the die 21; this width can therefore be modified either by making the part 24 movable relative to the die 21 in the direction of the axis 22, or by exchanging the part 24 for another of a different axial length; this arrangement allows the thickness of each of the transverse linear elements 33 to be adjusted to the desired value; it would obviously be possible for the part 24 to be fixed to the die 21, the width of the annular channel 25 then being invariable. As an alternative, the two dies 21 and 29

can be permanently maintained in a relative position such that the outlet of the annular channel 25 is always completely unobstructed, so as to extrude a solid tube; the linear elements that are then extruded by the transverse channels such as 31 of the two dies 21 and 29, or of only one of them, then form continuous longitudinal projections on at least one of the opposite faces of said solid tube; different materials can be used to ensure the extrusion of the solid tube and that of these longitudinal projections; the same possibility exists, moreover, in the general case, for the real-

different degrees; in the case where the outlet of the annular canal is always clear, means may also be provided for periodically modifying the width of the outlet of this annular canal, "5 so as to form on at least one of the faces of the extruded solid tube, continuous projections, transverse to the parallel continuous projections formed by the transverse canals*

Tubes with a lacunar structure, particularly a reticulated one,

Tubes manufactured by extrusion using the machine illustrated in Figures 12 and 13, particularly in synthetic materials, can be cut lengthwise and flattened into a sheet; these two operations can optionally be carried out, in the case of a relatively rigid synthetic material, before the material has solidified. The tubes themselves can be used, for example, to make various types of bags, by closing at least one of their ends by any known method, particularly by welding, especially before the material has solidified, by gluing, stapling, etc.

In the variant represented in cross-section by a diametrical plane on figure 14, it is the fixed die 21 which has an annular shape, its smooth ground surface 23 having in particular the shape of a zone of a cone of revolution; the mobile die 29 is on the other hand placed at the center of the annular fixed die 21, so that its ground surface 23, also in the shape of a zone of a cone of revolution, can be brought into tight contact with the ground surface 23 of the fixed die 21 by a movement in the direction of the arrow 22', that is to say in the direction of the common axis of the two dies 21 and 29; the ground surface 23' of the mobile die 29 is notched by channels with open section, in particular channels with a semi-circular section 31, and a single channel 31', of larger section, for example rectangular; 3. The material is brought, in a physical state suitable for its extrusion, into the annular distribution chamber 26, via the channel 28. When the die 29 occupies its lowest extreme position in

26 is extruded exclusively through the channels 31, 31*, forming respectively the vertical bars 38 and the wider vertical band 38'; when, on the contrary, the moving die 29 occupies the position shown in Figure 14, in which the two ground surfaces 3 and 3' of the two dies are separated from each other so as to leave between them a narrow annular interval 39, the material brought into the annular distribution chamber 26 is not only extruded through the channels 31, 31*, forming the vertical linear elements 38, 38', but is also extruded through the annular interval 39, forming an annular linear element such as 40; the various annular elements such as 40 which are formed successively during each of the periodic openings of the interval 39, resulting from the oscillatory movement of the mobile die 29 in the direction of arrow 22', welding at their points of intersection with the vertical elements 38, 38' so as to form a tube of reticulated structure, with a circular cross-section; by cutting this tube along the median longitudinal axis of its band 18'

and by developing it, one can obtain a kind of wire mesh frame with solid edges} these two operations can be carried out in particular before the solidification of the first layer.

In the embodiment illustrated in Figures 15 to 17, the fixed die 21 also has an annular shape, but with a rectangular outline; transverse channels 31, 31' are formed in its ground surface 23, differing in particular in the shape and dimensions of their cross-sections; the moving die 29 also has a rectangular outline, but no transverse extrusion channel is formed in its peripheral ground surface 23', which is made so as to be able to make a tight contact with the ground surface 23 of the die 21 when said die 29 is in its lowest extreme position; the material is brought by a conduit 28 into an annular groove 26, from where it passes into the extrusion channels 31, 31', and possibly also into the gap between the two dies 21 and 29; the j

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23* <is in contact with the ground surface 23 of the fixed die 21 we can therefore see that the material is extruded continuously through the intervals 42, 42', forming the two opposite solid walls 43, 43' of the tube with a lacunar structure T which is illustrated in Figure 17, in cross-section by a longitudinal plane: these two solid walls 43, 43' are connected to each other by two mesh walls, only one of which is visible in Figure 17; these; The wire mesh walls are each made up of vertical linear elements 44, 44', which are continuously extruded respectively through the channels 31, 31', and of horizontal linear elements 45, which are extruded into the interval that is periodically established between the ground surfaces 23, 23' of the two dies 21 and 29. The rectangular tube thus obtained can be split along one of its edges, possibly before solidification; it allows the production of packaging boxes, particularly in relatively flexible synthetic material, comprising at least two wire mesh walls.

Figures 18 and 19 schematically illustrate the operation of the most general embodiment of the machine according to the invention, which comprises two extrusion dies movable relative to each other, and at least one of which is provided with parallel channels. In Figures 18 and 19, the two dies 50 and 51 shown by way of example are straight and parallel; they could also be curved. They are provided with channels 53, 53', parallel to each other but perpendicular to the direction of extension of the dies, so that they are seen end-on in Figures 18 and 19. In the illustrated example, the channels with which the two dies 50 and 51 are provided have closed cross-sections, which differ in both their shape and their dimensions, not only from one die to the other, but also within the same die. Die 50, for example, comprises channels with

circular section 53, and channels 53' with rectangular section,

\

tondfo.mio ■Filière 51 ne comDorte aue des canaux à »•—

cular 53; on the other hand, the two dies DU and ûi have different numbers of channels, and the channels of one are not arranged opposite the channels of the other; finally, the two dies 50 and 51 can be moved relative to each other, one being, for example, fixed and the other movable. It is already known to use pairs of dies of this kind to manufacture sheets, plates, or tubes of reticulated structure, by moving the two dies 50 and 51 relative to each other in the direction of arrow 54 in Figure 19, that is to say, by sliding the two dies 50 and 51 while keeping them in contact with each other, or at least at a constant distance from each other. The present invention, on the contrary, proposes to manufacture sheets, plates or tubes with a porous and in particular reticulated structure using a pair of movable dies such as that illustrated in Figures 17 and 18, by alternately bringing one of the two dies closer together and moving them apart in the direction of arrow 55 in Figure 18: the process of forming the reticulated structure is then as follows: when the two dies 50 and 51 are brought into contact with each other as illustrated in Figure 19, the material, which is assumed to be continuously fed over the two dies 50 and 51,

in the direction of their channels 53, 53', is extruded only through said channels 53, 53', forming as many parallel linear elements between them, which, in Figure 20, have been designated by the same reference numbers, followed by the letter a, as the extrusion channels which formed them. When, on the contrary, the two dies 50 and 51 have been separated from each other in the direction of arrow 55 and there is consequently between them an interval 56 of uniform width, as shown in Figure 18, the material is also extruded through this interval 56, forming a single linear element, transverse with respect to the parallel linear elements extruded through the channels 53, 53'; In the illustrated example, where these channels 53, 53' have closed sections, the junction between the linear elements 53a, 53'a, and the linear elements 56a which are formed successively, obviously takes place after the exit of the ma-

say below the 50 and 51 dies in the example illustrated in figures 18 and 19; As an alternative, the channels 53, 53' of the dies 50 and 51 can, on the other hand, open outside the corresponding die, that is to say in the interval 26 existing between the said dies when they are separated from each other (fig. 18), the said channels being closed by the wall of the other die when they touch (fig. 19); in this case, the junction between the linear elements 53a, 53'a, and the linear elements 56a takes place precisely in the interval 56 between the two dies 50, 51. In the example just described, the linear elements 53a, 53'a are found on one side or the other of the linear elements 56a, depending on whether they have been closed by the die 50 or the die 51; they can all be obtained from one side of said linear elements 56a by removing the extrusion channels of the other die; it is finally possible to obtain a sheet or plate of reticulated structure having a thickness, by also providing means to obstruct the outlets of the channels of the extrusion dies 50, 51 when these are separated from each other (fig. 18).

A particular operating method for the machine which has just been described with the help of figures 18 and 19 consists of maintaining its two dies 50 and 51 permanently at a constant distance from each other, so as to ensure simultaneously the continuous extrusion of the material through the channels 53, 53' of the 5,5* two dies, as well as through their gap 56 (fig. 18); the product thus manufactured consists of a sheet or plate of uniform thickness, presenting on at least one of its two faces continuous parallel projections, analogous to reinforcing ribs; by periodically changing the spacing of the two dies, one can also form continuous projections*, transverse to the previous ones.

In figures 21 and 23, a cross-section is shown by a plane perpendicular to the direction of flow of the ma-

machine whose operation has been explained previously with the help of figures 18 and 19; the representation has been limited in each case to the two dies 50 and 51, which are mounted so as to be able to slide relative to each other in a direction perpendicular to their extrusion channels 53, 53*, which is indicated by the arrow 55; more precisely the die 50 has an internal recess, in which the die 51 is embedded so as to be able to be moved alternately between two positions,

one in which the two dies 50, 51 are in contact by their faces adjacent to their extrusion channels 53, 53* (fig. 21), and the other in which said faces of the two dies 50 and 51 are separated from each other so as to provide between them an interval 56 (fig. 23); in the embodiment of figure 21, only the movable inner die 51 has extrusion channels, open on the face of said die 51 which is turned towards the die 50; there are two kinds 53 and 53', differing in the shapes and dimensions of their cross-sections in the embodiment of figure 23, on the other hand, only the fixed die 50 has extrusion channels 53, of closed cross-section, and all identical to each other.

We will briefly describe the production of the wire mesh frame in Figure 22 using the two dies in Figure 21: the two solid "vertical" edges 58, 58' of the frame in Figure 22 are formed by continuous extrusion of the material through the 2*5 recesses 62, 62* of the die 50 in Figure 21, which are never obstructed by the die 51 during its movements; the vertical bars 6 are formed by extrusion of the material through the channels 53 of the die 51; the median strip 59 is also formed by extrusion of the material through the channel 53' of the die 51; the horizontal bars 8 connecting the edges 58, 58' of the frame and the vertical bars 6, as well as the median strip 59, are formed by extrusion of the material through the existing gap between the two channels 50 and 51 when the face of channel 51 onto which the channels 53, 53' open comes to coincide sensi-

I*i'

βlement with the plane whose trace is shown by the dashed line §3 in Figure 221; means can obviously be provided to then obstruct the outlets of the extrusion channels 53, 53' so as to interrupt the formation of the vertical bars 6 and the 5 median strip 59 during the formation of the horizontal bars 8. The fusion between the vertical elements 58, 58*, 59 on the one hand and the horizontal elements 8 and 60 - the latter forming the lower solid border of the frame - takes place in the interval between the two dies 50 and 51, through the open parts of the extrusion channels 53, 53' #

In the case of the plastic packaging crate with a wire mesh base, which is shown in Figure 24, the solid sides 61, 61' are formed by continuous extrusion of the material through recesses 64, 64' of the fixed die 50, which are never obstructed by the die 51; these recesses 63, 63' also allow the formation by continuous extrusion of the solid edges 58, 58' of the wire mesh base of the crate; the horizontal strips 8 of this wire mesh base are formed by extrusion of the material through the gap 56 existing between the two dies 50 and 51 when they occupy the respective positions illustrated in Figure 23; the vertical bars 6 of the wire mesh base are formed by continuous extrusion of the material through the closed cross-section channels 53 of the fixed die 50, the outlets of these channels being kept permanently open; so that the junction between the vertical bars 6 on the one hand, and the horizontal elements of the bottom of the box u8 and 60 on the other hand, is made below the dies 50 and 51, that is to say beyond the outlets of the extrusion channels 53.

In the variant of figures 25 and 26, the die 51 3o has open extrusion channels 53^ , 53g on its two faces which can cooperate with the corresponding faces of the internal recess of the die 50 during its movements in the direction of arrow 5; a sort of tube with a rectangular cross-section is obtained, presenting nothing* efttéa , ... _. ....

Claims (1)

dies continuously through the intervals of constant width '64, 64', as well as two other gridded sides, which are made in the same way as the frame of figure 22, their horizontal elements 8 being only offset in height as seen on figure 26; a plate 13 with a rectangular ring slot is arranged below the dies 50 and 51 (figure 26) to regularize the thickness of the extruded tube; by slitting this along one of its edges, a packaging element can be obtained, in particular in flexible synthetic material. In the embodiment illustrated in figures 27 and 28, the die 50 alone is provided with extrusion channels 53C substantially parallel to the direction of the relative movement of the two dies 50 and 51 and to the direction of arrival of the material to be extruded 2; in the relative position illustrated in figure 27, the material is extruded exclusively by the channels 53 forming as many parallel (vertical) linear elements 6; in the relative position illustrated in figure 28, the material is extruded in addition by the uncovered slot between the two dies 50, 51, forming a single (horizontal) linear element 8; of course, appropriate means y ^, not shown, can then interrupt the formation of the parallel elements 6. - DEMANDS - 1 - A process for the continuous manufacture of profiled parts, such as sheets, plates, tubes, etc., having a porous structure, particularly a reticulated one (mesh, netting, netting, fabric, etc.), especially in synthetic materials, characterized in that it consists of continuously flowing the liquid or pasty material along a sheet having the cross-section of the profiled part to be manufactured, creating the necessary voids in this sheet û ! i by preventing the flow of material at the corresponding locations, then to immediately solidify the resulting porous layer. 2 - Machine for the continuous manufacturing of profiled parts such as sheets, plates, tubes etc... featuring a 5. A lacunar structure, in particular a reticulated one (mesh, lattice, net, fabric, etc.), especially in synthetic material, characterized by the fact that it essentially comprises at least one die for extruding the material according to the profile to be obtained, as well as means to prevent at least temporarily the material from exiting said die at the places corresponding to the necessary gaps, and to solidify it as soon as it exits the die. 3 - Machine according to 2, characterized by the fact that the means, for temporarily preventing the material from exiting the die at the places corresponding to the gaps in the part to be manufactured, consist of a system of combs, the teeth of which can be temporarily brought across the exit of said die. 4 - Machine followed 3, characterized by the fact that each comb is mounted in the immediate vicinity of the outlet of the die, so as to be able to be moved, preferably perpendicular to said die, between a position where its teeth partially obstruct the outlet of the die and another position where its teeth are erased with respect to said outlet. 5 - Machine according to 3, characterized in that §,•5 the die and the comb system are permanently maintained at the extrusion temperature of the material. 6 - Machine according to 3 for the continuous manufacture of a sheet or plate of reticulated structure with rectangular or square meshes, characterized in that the comb system comprises a single comb, preferably with straight teeth, mounted so as to be able to slide perpendicularly to the flat die, and that the ratio between the successive time intervals during which the teeth of said comb partially obstruct the outlet of the flat die, and those during which the teeth are obliterated, es'fc^,>| chosen equal to the ratio between the width of the meshes and 1*thickness of the wires or bars of the network to be made. 7 - Machine following 3, for the continuous production of a sheet and a plate of reticulated structure with rectangular meshes 5" or square, characterized by the fact that the comb system is combs ^ consisting of two identical combs, rigidly assembled together so that the ends of all the teeth of one are opposite the ends of the teeth of the other, from which they are separated by an interval at least equal to the width of the outlet of the flat die, and that this comb system is mounted so as to be able to slide perpendicularly to said flat die, between two positions where the teeth of one or the other comb partially obstruct the outlet of the flat die, passing through an intermediate position where the outlet of the flat die is completely clear. 8 - Machine according to 3, for the continuous manufacture of a mesh or a reticulated structure plate with diamond or hexagonal meshes, characterized in that the comb system consists of two identical combs, preferably with teeth ^ pointed, rigidly assembled one with the other so that the ends of all the teeth of one come to be inserted in the middle of the intervals between the teeth of the other, and to be placed at the same distance from the bottoms of these intervals, this distance being at least equal to the width of the outlet of the flat die, and that this system of combs is mounted so as to be able to slide perpendicularly to the said flat die between two positions, where the bottoms of the intervals between the teeth of one of the other combs are substantially opposite the outlet of the flat die, so that the latter is then partially obstructed only by the teeth of only one of the two combs, passing through intermediate positions, where the outlet of the flat die is partially obstructed at the same time by the teeth of both combs. 9 - Next machine 3, for continuous manufacturing ^ p4—\ of a reticulated tube with rectangular or square meshes, using an elongated rectangular die, the outlet of which has a uniform width*, characterized by the fact that the comb system consists of at least one group of two combs, rigidly assembled together so that the ends of the teeth of one are separated from the ends of the teeth of the other by an interval at least equal to the width of the die outlet, and that this comb system is mounted so as to be able to slide perpendicularly to the two long sides of the rectangular die outlet, in two extreme positions, where the teeth of one of the two combs partially obstruct the outlet of one of the long sides of the die, while the outlet of the other long side of said die is completely unobstructed* 10 - Machine according to 3, characterized in that means are provided to prevent material from passing through the gaps between the teeth of the comb system when said teeth are offset from the die outlet, in particular to obtain a sheet, plate, or tube of a porous structure having a uniform thickness, and that these means are preferably provided either by fixed parts interposed in - SU, tre les. dents du system de combs, soit par un pièce appliqué contre la visage de la system de combs contraire à la die, ces différents pièces étant au autre disposition pour se obstruction des intervals entre les dents de system de combs sans ^5 opposer de ses déplacements à la rapport de la dit die, nor obstruction de l’out de l’e ... 11 - Machine according to 3, - characterized by the fact that, when the teeth of the comb system have been brought across the outlet of the die, their ends cooperate with a piece located in or formed by the extension of the edges of the outlet of the die. 12 - Machine according to 2, comprising two straight or curved extrusion dies, movable relative to each other the other and juxtaposed by faces preferably parallel, in the vicinity of which at least one of said dies comprises one or more extrusion channels, parallel to each other, characterized by the fact that it is provided with means for animating the two dies with an alternating reciprocal movement having no component transverse to their extrusion channels, so that the material is extruded through said channels in the form of linear elements (such as bars, strips, wires... etc.) parallel to each other and/or periodically, in the form of a single linear element, transverse to said parallel linear elements. 13 - Machine according to 12, characterized in that it further comprises means for obstructing the outlets of the extrusion dies during the formation of each transverse linear element, in particular to obtain a sheet, a \S plate or :iun tube of lacunar structure exhibiting a uniform thickness. 14 - Machine according to ':J12, characterized in that the extrusion channels with which at least one of the two dies is provided may differ from each other in the shape and/or dimensions of their cross-section, which may also be closed or open with respect to the other die" 15 - Machine following 12, characterized in that the extrusion channels with which each of the two dies may be provided can differ from one die to the other in their number, ^ as well as by the shape and/or dimensions of their section, which 4f small be further closed or open with respect to the other channel. 16 - Machine following 12, characterized in that the two dies have ground surfaces on their juxtaposed faces by which they can be brought into contact with each other# 17 - Machine according to 16, characterized in that the extrusion channels with which at least one of the two filaments is provided -OKKiXV- The ères have their section open on the ground surface of the corresponding die. 18 - Machine following 12, characterized by the fact that conduits and possibly a distribution channel 5- tion, for example annular, are arranged in the fixed die or in the juxtaposed faces of the two dies, to bring the material to be extruded to the entrances of the different eutrusion channels. 19 - Maehine. following 12, characterized by the fact that means are provided to maintain the two dies in the vicinity of the extrusion temperature of the material f for example in the form of a heating sleeve attached to the die fie. 20 - Machine according to 18, characterized by the fact that means are provided for obtaining sheets, plates or tubes of lacunar structure - exhibiting parallel bands - The gitudinales are variously colored, and possibly of various widths, for example by subdividing the material distribution chamber into a corresponding number of compartments, fed independently of each other. 21 - Machine following 12, characterized by the fact that t Its two dies are maintained in an invariable position relative to each other, so that the material is constantly extruded between their juxtaposed faces in the form of a sheet, plate, or tube of uniform thickness, as well as through their extrusion channels in the form of continuous protrusions. £§" parallel on at least one of the faces of said sheet, continuous transverse projections relative to the previous ones may have formed periodically increasing the gap between the two dies. 22 - Machine according to 12, characterized in that the parallel extrusion channels with which at least one of its two dies is provided are arranged so that the linear elements of extruded material exiting them form a sheet, and that a single extrusion channel is further arranged transversely to said parallel extrusion channels so as to open near ■m. m- "v" 'v-:- 1 - ;Ï!; -,.e I' their outlets, the outlet of said single channel being able to be, for two different relative positions of the two dies, either obstructed at least locally, or totally cleared so as to extrude a linear element of material, transverse with respect to said parallel linear elements" 23 - Machine according to 22, characterized by the fact g that the transverse extrusion channel is arranged in one of the two dies so that its outlet can be obstructed at least locally by the other die for a determined relative position of the two dies. 24 - Machihe following 23, characterized by the fact that one of the two walls of the transverse extrusion channel arranged in one of the two dies is formed by a fixed part to said channel, in particular so that it can be moved or exchanged to adjust the width of the outlet of said channel. 25 - Machine following 22, characterized in that the transverse extrusion channel is delimited by the two dies so that its outlet is constricted, at least locally, when the two dies are brought into contact with each other. 26 - Machine following 22, for extruding a tube with a porous structure, characterized by the fact that one of the two dies has a cylindrical shape and the other the shape of a ring, mounted around the first one in such a way as to allow their relative sliding. 27 - Machine following 26, characterized by the fact that means are provided to modify the shape and/or dimensions of the section, and possibly the length of the extruded tube, before its solidification. 28 - Profiled parts with a gap structure and in particular a reticulated structure, such as wire mesh, netting, netting, fabrics, etc., manufactured by extrusion, particularly in synthetic materials, characterized by the fact that they have a uniform thickness, including a level of the crossing points of bars, strips or wires that constitute them. 29 - Reticulated structure tube (mesh, lattice, net, fabric, etc.), manufactured by extrusion, particularly in synthetic material, characterized by the fact that at least some of the parallel linear elements (such as bars, strips, wires, etc.) that form its mesh are oriented longitudinally and others transversely, which gives the tube perfect dimensional stability. p.p. Société Anonyme R cal The Agent- ORIGINAL 31 pages. Without erasures or overwriting, 1 word, interlinear, Pj26 pp. Sosj An.Rical T i g TVff*} n ^