WO2015114177A1

WO2015114177A1 - Method and machine for producing mesh sheets

Info

Publication number: WO2015114177A1
Application number: PCT/ES2014/070073
Authority: WO
Inventors: Juan Antonio Torres Vila
Original assignee: 3S Geotecnia Y Tecnologia S.L.
Priority date: 2014-02-03
Filing date: 2014-02-03
Publication date: 2015-08-06
Also published as: EP3103926A4; EP3103926A1

Abstract

The invention relates to a method and machine for producing mesh sheets, wherein: wires are shaped such as to form a spiral with each wire; different adjacent spirals are interlaced with one another, in pairs, in order to create a mesh; different meshes are interlaced with one another in order to create a mesh assembly (3); a lateral closure is made at both lateral ends (30) of the mesh assembly (3); and the mesh assembly (3) is subjected to a pre-stressing process, thereby producing a mesh sheet. The lateral closures of a mesh assembly (3) are made simultaneously, and each lateral closure is made by creating a plurality of closure knots. Each closure knot is made by twisting one end of one spiral around one end of another spiral, and by subsequently bending the ends inwards.

Description

DESCRIPTION

"Procedure and machine for the manufacture of mesh canvases"

SECTOR OF THE TECHNIQUE

The present invention relates to manufacturing processes for steel wire mesh canvases, more specifically to those manufacturing processes for single wire steel wire mesh canvases, with machines adapted for manufacturing mesh canvases of this type. . Likewise, the present invention also relates to the possible field of application of steel wire mesh canvases obtained from the claimed manufacturing process or with the machine.

PREVIOUS STATE OF THE TECHNIQUE

In general, a steel wire mesh canvas consists of a metallic framework obtained by braiding or weaving steel wires, of which there are different typologies that differ from each other generally by their different geometric configurations, by their manufacturing procedure, by the size of the internal crosslinking, by the use of different diameters and resistance of the wires or by the use of different types of corrosion protection among others. In general, steel wire mesh canvases constitute a widely used element in a large number of applications, with a history of different types of steel wire mesh canvases used primarily in enclosures and industrial uses being known, in these cases, No structural function. In a general way and from now on, the structural function will be understood as the mechanical behavior of steel wire mesh canvases when, subject to external actions or forces, a flat tension state of the canvas or a plurality of canvases is derived of meshes when these are connected to each other. It is understood as the flat tensional state of the element the tensional physical state that is produced in it by the efforts generated and that are contained in the plane of the mesh canvas that are caused by external actions or forces, which can be applied both in the directions contained within the plane that forms the canvas of meshes, as in the direction perpendicular to it or a combination of both.

Characteristic is the behavior, both of the mesh of meshes and of the mesh canvases connected to each other, according to which, before external actions, mainly in the direction perpendicular to the plane that contains it, tensile stresses are generated inside in the directions contained in the plane of the same, where the main direction is identified as the longitudinal direction where the resistance is greater and the secondary direction as the transverse direction where the resistance is equal to or less than the main one, being able to assimilate its behavior from the physical point of view and mechanical like that of a structural membrane.

The structural function of a membrane is characterized by the fact that the element must have a tensile strength such that it can withstand the external actions to which it will be subjected under a controlled stress-strain behavior, which implies that the levels of deformation must be low for high effort levels caused by external actions or forces. In general, the structural membranes have a two-dimensional character, which means that two dimensions predominate over the third, which is negligible.

In general, within the different steel wire mesh canvases, those comprising hexagonal inner reticles, known colloquially as double or triple twist meshes, are known and customary. This typology of steel wire mesh canvases are manufactured by weaving, presenting an inner lattice formed by individual hexagons that arise from the fabric by repeated twisting of two wires alternately, so that these twisted wires run in the longitudinal direction from braided and diagonally to one side and the other until the canvas of steel wire meshes is obtained.

In this case, the type of wire is limited to the use of ductile steel, which has the quality of being easily folded, which makes it suitable according to the method of manufacturing by commented fabric, which causes a plastic deformation on the wire by repeated torsion without recovering its original form once the manufacturing action that conforms it ends. The tensile strength of the wire used to allow this type of manufacturing generally reaches 550MPa with wire diameters generally less than or equal to 3.0mm. These characteristics are those that allow the manufacturing of the canvas of meshes by bending and twisting the constituent wires thereof in the manner described without causing breakage in the wires or dismantling of the canvas fabric once manufactured.

This type of mesh canvas is characterized by its flat or two-dimensional character, given the type of fabric and fabric manufacturing procedure which would make it preliminary for use as a structural membrane. However, due to external actions, it has a very high deformation, so its use as a structural membrane is not suitable.

Also colloquially called simple twist meshes are also common and known within the different steel wire mesh canvases. In this case the manufacturing process also uses technology of a traditional nature and widely known as in triple or double twist mesh canvases. In this case, a folding or bending of the steel wire is carried out which allows the formation of individual wire turns, which are placed transversely to the manufacturing progress of the mesh of meshes, are interwoven with each other two by two to generate meshes and these are intertwined obtaining the final configuration of a canvas of steel wire meshes.

The manufacturing process begins with the formation of the individual turns from the steel wire, obtained by bending the wire along a tool that rotates with a spiral groove and that pulls the wire to form the spiral, which is characterized by an angle of advance, a height, a length of passage and an interior light of the spiral that is achieved by the configuration of the manufacturing tool. The variation of these parameters allows obtaining different geometric configurations. Therefore, the characteristics of the type of wire used are such that the ductility of the steel must allow the fabrication of the turns by bending the constituent wires, and steel wires with a diameter of up to 5.0mm and generally tensile strength can be used not exceeding LOOOMPa. This type of mesh canvas is characterized by its three-dimensional character, given the type of fabric and braided manufacturing process. The three-dimensionality of the fabric is marked by the interior light of the loop that is obtained in manufacturing. This three-dimensionality causes that, under the hypothesis of its use as a structural membrane before external actions that generates a tensional state inside the canvas of steel wire meshes, it presents a very high deformation, by reversing the three-dimensionality of the element, therefore its use as a structural membrane is not suitable. In particular, this type of steel wire mesh canvases or the union of several individual canvases, when subjected to external actions present the problem of high deformation mentioned, phenomenon controlled mainly by the three-dimensionality of the mesh of meshes, among other factors . This phenomenon becomes more pronounced the greater the tenacity of the wire, which also hinders its bending and therefore does not reduce the interior light of the loop. Therefore, this deformation under the action of external loads is excessive to allow the use of these canvases of simple twist steel wire mesh or the union of several canvases as a structural membrane.

In general, the deformation of the canvas of meshes of simple torsion under external actions has three components, the first component being a function of the manufacturing process and of the form that the mesh of the mesh of meshes itself acquires and which gives it a three-dimensional character. In particular, in the canvases of simple torsion meshes manufactured by individual bending of turns and interlacing thereof, this phenomenon is controlled by a reduction of interior light of the individual turns and by a reduction of the radius of curvature of the vertices of the windings when subjected to external actions that cause tensile stress inside the mesh of meshes. This deformational component is permanent and non-recoverable after the end of the application of the external actions, since the canvas of meshes when subjected to stress is deformed in a plastic way, reducing the interior light of the turns that make up the canvas of meshes and decreasing the radius of curvature of the vertices of the turns, resulting in permanent deformation in the main direction of the mesh of meshes.

The second component is a function of the type of lateral closing knots of the turns used in the manufacture of the mesh canvas. This deformational component is of permanent and non-recoverable character after the end of the application of the external actions since the canvas of meshes, being subjected to stresses, at the same time as the reduction of the interior light of the turns and reduction of the radius of curvature in the vertices of the turns, also tends to open the lateral closing nodes of the turns, and as a result introduces a deformation in the main direction of the mesh of meshes. In a usual and known manner, the ends of steel meshes of the simple twist type closed ends by bending the wires on themselves have been used for the manufacture of the steel mesh canvases. This type of closure does not allow interconnection between mesh canvases or the application of significant transverse stresses to the joint line if two mesh canvases are joined by the knot line.

The third component is elastic, due to the deformation of the steel under the stresses caused by the external application of actions. This deformational component is recoverable provided that the elastic range of behavior of the materials is not exceeded, and it is controllable, from the physical point of view, since it is a function of the magnitude of the external actions applied on the mesh of meshes and mechanical characteristics of said mesh canvas.

Therefore, conventional plain torsion mesh canvases may have a suitable tensile strength due to their geometric configuration and the type and diameter of the steel wire used, but they have a deformational creep phase when subjected to external actions. This phenomenon is characterized by a non-recoverable deformation for low increases in load or external action at the beginning of its application. This deformation is a function of the structure of the fabric of the steel wire mesh canvas, in particular of the interior light of the turns, as well as the type of lateral closure of the turns.

In particular, the existence of simple torsion mesh canvases made of high elastic steel wire, with resistance of steel wires that can reach 2,200MPa, is pointed out. The production of these mesh canvases requires a complex production process and specific technology due to the difficulty of folding and manufacturing of flat turns with high elastic steel wire due to the lack of ductility of the steel wire and the excessive fragility of the steel. Same product of its high tenacity. Although these mesh canvases have a high tensile strength, in practice they present the problems of deformational creep when subjected to actions External function of the structure of the fabric of the wire mesh of steel wire marked by the interior light of the turns, as well as by the type of lateral closure of the turns. In addition, they present specific problems induced by the fragility of the wire which causes that, under external actions of a punctual or concentrated nature, their breakage or failure occurs for loads less than theoretically expected.

In the field of Geotechnics, and in particular in the treatment of slopes and slopes, applications are known in which structural membranes are used within a mechanical system constituting a flexible stabilization and slope protection system.

These systems have the function of avoiding the movements of the ground since they fix the unstable soil and rock masses in their original position avoiding their displacement, where the structural membrane formed by different canvases are connected to each other continuously, with a support function of the efforts generated by possible movements and thrusts of the terrain, combining said structural membrane with bolts anchoring to the ground that deepen the stable area of the terrain.

Said structural membrane is subjected to terrain actions that result in tensile stresses and that requires its attachment to the anchor bolts by means of bracing elements and plates that allow the transmission of these efforts, offering coverage to the ground surface and functioning as a support or distribution element of the stabilizing pressure. This structural membrane obtained by the application of a mesh of meshes or the union of different canvases of meshes, so that they are efficient from the mechanical point of view within the system in which they are used, must be characterized because when acting as a membrane they must offer a high tensile strength but with a low deformation against the thrusts exerted by the ground. Therefore, the typology of the canvas must be specifically adapted to the structural membrane requirements described above, in particular, to the requirement of offering a high tensile strength with a low level of associated deformation. This implies that steel wire mesh canvases manufactured by traditional production processes are not suitable for this application due to their excessive deformation under the action of external loads, which is why traditionally wire mesh mesh networks have been used as structural membrane. steel cable, and When steel wire mesh canvases obtained by traditional processes have been used, these have resulted in failures due to the collapse of the slope due to the high deformation of the element used as a structural membrane. In addition, individual mesh canvases must allow their connection securely, guaranteeing the transmission of efforts. For this, it is necessary that in the case of using steel wire mesh canvases as a structural membrane, these have resolved the lateral closing knot of the turns at the edge of the canvases, so that it does not introduce deformation to the structural system or they present a failure under the action of the external loads, also allowing the connection between canvases of adjacent meshes.

In the field of Geotechnics, containment and protection kits against rockfalls and impacts are also known, of the type barriers or dynamic screens composed of a structure anchored to the ground and a collection element or surface connected to the previous structure, between other solutions, steel wire mesh canvases whose function is to serve as an interposing element in the face of possible landslides and thrusts of the ground (and / or snow). The catchment surface is understood as the surface that interposes, supports and retains possible landslides or impacts. In general, in these systems, the deformation of the pick-up element is not a limiting aspect in the use of these types of solutions, but the mesh canvases to be used require a solid connection between the individual mesh canvases to withstand the impacts. In addition, the need often arises, unresolved so far, that deformation in the face of an impact must be controlled and limited, or the thrusts exerted by the ground and / or snow on a containment structure must be limited, so In these cases, the use of a structural membrane with low deformation is required as a collection element.

Under the considerations described above referring to the current state of the art related to the use of steel wire mesh canvases obtained directly from traditional or industrial manufacturing processes, it is not possible to directly apply them as a structural membrane, given the high effect that in its tension-deformation behavior has both the type of node of the lateral closure of the turns that conform it and the three-dimensional structure controlled by the interior light of the turns that form the framework. In document ES 2374127 A1 of the applicant itself a process for the manufacture of prestressed mesh canvases is disclosed so that said mesh canvases do not exhibit structural deformations.

EXHIBITION OF THE INVENTION

An object of the invention is to provide a process for manufacturing mesh canvases as defined in the claims.

In the manufacturing process of the invention, at least a plurality of steel wires are actuated to form, with each wire, an individual loop of a given width, different adjacent turns are intertwined to generate a mesh of a given width each two turns, different meshes are intertwined with each other generating a set of meshes, a lateral closure is made on both lateral ends of the set of meshes and said set of meshes is prestressed obtaining a prestressed mesh of meshes. In the process, in addition, the two lateral closures are made simultaneously and each lateral closure is made by generating a plurality of closing nodes, generating a closing knot for each mesh and making said closing knot through a twisting of one end of one of said turns with one end of the other turn, by a subsequent rotation of one end over the other end an angle of rotation such that it allows to maintain some ends of said ends in the plane of the mesh, and by folding back of said tips into the mesh assembly; and, once the lateral closures have been generated, in the procedure the set of meshes is subjected to a prestressing treatment under controlled load in the direction perpendicular to the meshes that coincides with the longitudinal direction of the set of meshes, obtaining the canvas of mesh.

With the method of the invention, non-deformable closure knots are obtained that allow an appropriate prestressing to be obtained to obtain a mesh of meshes that can act, for example, as a structural membrane (which requires a controlled tensile behavior and with low levels of deformation low load or external actions of the mesh of meshes) or as a collection surface with controlled deformation, since the closing nodes, due to their non-deformable character obtained by how they were made, are not affected during prestressing; and even allow an easy and robust joining of different mesh canvases to each other to increase the size of the structural membrane and / or the containment kit.

In addition, with the closing knot obtained, the phenomenon of discouragement is avoided in the face of efforts that are generated in the mesh of meshes by application of external actions, once said canvas of meshes is in the field. These efforts cause a tendency to reverse the twists made and, due to the folding of the tips, in the closing nodes obtained during the process of the invention the twisting is tightened into the set of meshes (mesh canvas in this case) , preventing the closing knot from unraveling, acting even in the opposite way on said closing node since this action tends to tighten the closing node more, thus giving said closing node greater resistance and therefore a non-deformable character

In addition, thanks to the combination of the closing nodes thus generated and the prestressing of the mesh set, a mesh of meshes is obtained with reduction of the three-dimensional character by reduction of the interior light and the radius of curvature of the vertices of the individual turns. Additionally, thanks to the ends of the ends of the turns that make up a mesh remain in the plane of the mesh once turned, an easy transport and manipulation of the mesh cloths is allowed to avoid possible snagging or awkward situations with those tips , and also facilitate the implementation of mesh canvases for final application since these points must not be taken into account during said implementation.

Another object of the invention is to provide a machine in which the manufacturing process of a mesh canvas as described above can be implemented. Thus, thanks to the machine, a mesh canvas is obtained with at least the advantages already mentioned.

Another object of the invention relates to different possible applications of the mesh canvas obtained with the process of the first object of the invention and / or with the machine of the second object of the invention, such as its use as a flexible stabilization and protection system. of slopes (as a structural membrane), avoiding the three-dimensionality of the mesh of meshes thanks mainly to the typology of the closing knots; or as a containment and protection kit against rockfalls and impacts (as a collection surface with controlled deformation). These and other advantages and features of the invention will become apparent in view of the figures and the detailed description of the invention.

DESCRIPTION OF THE DRAWINGS

Figure 1a shows a loop formed according to a preferred embodiment of the process of the invention.

Figure 1b shows a mesh formed by the interlacing of two adjacent turns of Figure 1a, during the preferred embodiment of the process of the invention.

Figure 1 c shows a set of meshes formed by interlacing a plurality of meshes according to Figure 1 b, during the preferred embodiment of the process of the invention.

Figure 2 shows a side end of a mesh, with the two ends of the turns that make it up.

Figure 3a schematically represents the application of a twist of the end of one turn on the end of the other turn of Figure 2, during the formation of a closing knot according to a first embodiment of the method of the invention, where they are shown one resulting tips from each end.

Figure 3b schematically represents the folding of the tips of Figure 3a, to form the closure node according to the first embodiment of the process of the invention.

Figure 4a schematically represents the application of a twist of the end of one turn on the end of the other turn of Figure 2, during the formation of a closing knot according to a second embodiment of the method of the invention, where they are shown one resulting tips from each end. Figure 4b schematically represents the folding of the tips of Figure 4a, to form the closure node according to the second embodiment of the process of the invention. Figure 5 shows an elongation that is generated in a set of meshes during a prestressing process of the process of the invention, to obtain a canvas of meshes according to the invention.

Figure 6 schematically shows an embodiment of a machine according to the invention.

Figures 7a-7c show a knotting unit according to the machine of Figure 6, with different evolutions of the prestressing process of the process of the invention.

Figure 8 shows a connection detail of an embodiment of a mesh canvas of the invention employed in a slope stabilization and protection system with point connection.

Figure 9 shows a connection detail of an embodiment of a mesh canvas of the invention, used in a slope stabilization and protection system with a bracing line.

Figure 10 shows a connection detail of an embodiment of a canvas of meshes of the invention, used in a slope stabilization and protection system with two bracing lines.

DETAILED EXHIBITION OF THE INVENTION

A first aspect of the invention relates to a method of manufacturing steel wire mesh canvases. The process is initiated by acting on a plurality of steel wires to form, with each wire, a loop 1 of a width A determined as shown by way of example in Figure 1 a, by a winding process in which preferably, at least two wires or wires are operated simultaneously, which provides greater performance than traditional procedures where a single wire or wire is used. The process is then continued by interlacing different adjacent turns 1, two by two, as shown by way of example in Figure 1 b, to generate with each interlaced between two turns 1 a mesh 2 with a width equal to the determined width A, as shown by way of example in figure 3a, and the different successive meshes 2 are intertwined with each other generating a set of meshes 3 as shown by way of example in figure 1c.

The manufactured turns 1 are automatically interwoven with each other, composing sets of meshes 3 with a width A defined by the length of the turn 1, preferably between approximately 2.0 meters and approximately 3.5 meters as this is the most usual measure for the most common applications (for example as a structural membrane or protection kit, which will be discussed later), being in any case different widths to this one.

Once the set of meshes 3 is obtained, a lateral closure thereof is made on both lateral ends 30. Each lateral closure is made by knotting the turns 1 that share the same mesh 2 with each other. In this phase, the lateral closure is carried out simultaneously on both lateral ends 30 of the set of meshes 3, generating a plurality of closure nodes 7; 7 'sides with non-deformable character and high strength in each side closure. Each closing knot 7; T is formed, firstly, by twisting the ends 5 of the two turns 1 that share the same closing node 7; 7 ', and for this purpose, one end 5 of one turn 1 is rotated on the end 5 of the other turn 1. Subsequently, points 6 resulting from the turns 1 are folded, after twisting, into the assembly of meshes 3.

In this way, with the closing knot 7; 7 'obtained the phenomenon of discouraging is avoided before efforts generated in the final mesh 4 by application of external actions, once said canvas of meshes 4 is in the field, which causes a tendency to reverse the torsions made, since due to the fold of the tips 6 the twisted is pressed towards the inside of the set of meshes 3 (canvas of meshes 4 in this case), preventing the knot from falling apart, even acting in the opposite way since this action tends to tighten plus the closing knot 7; 7 ', conferring on said closing node 7; 7 'greater resistance and hence its undeformable character. In a first embodiment, the rotation of one end 5 of one turn 1 over the end 5 of the other turn 1 to generate a closing knot 7 is approximately 360 °. The method of generating the closing node 7 according to the first embodiment is shown in Figures 3a-3b from the state shown in Figure 2.

In a second embodiment, the rotation of one end 5 of one turn 1 over the end 5 of the other turn 1 to generate a closing knot 7 'is approximately 180 °, and the tips 6 are fixed to the set of meshes 3, specifically to the corresponding turn 1, by electric welding or by another equivalent joining method. Thus, the degree of torsion that marks the rotation of one end 5 on the other end can be reduced to approximately 180 ° with respect to the first embodiment. In this case, it is the configuration of rotation, folding and electro-welding together that helps to avoid the phenomenon of opening of the closing nodes 7 ', preventing the closing node 7' from falling apart. The method of generating the closing node 7 'according to the second embodiment is shown in Figures 4b-4c from the state shown in Figure 2.

In the two described embodiments the process of formation of the closing nodes 7; 7 'is done automatically and simultaneously. In the process of the invention, in any of its embodiments, once the closure nodes 7 have been made; 7 ', the prestressed treatment is carried out by stretching under controlled load of said set of meshes 3, obtaining as a result of prestressing the mesh of meshes 4. In this phase of the manufacturing process it is where the structural deformation of the framework due to the three-dimensionality thereof by reduction of the interior light of the turns 1 and by reduction of the radius of curvature of the vertices of said turns 1 that configure the mesh of meshes 4. Such treatment is possible due to the previous obtaining of the closing nodes 7; 7 'of non-deformable character as described above. Therefore, they are the closing nodes 7; 7 ', executed according to the method described above, which allow the prestressing treatment to be carried out under controlled loading of the set of meshes 3 to obtain the mesh canvas 4, due to the non-deformable character thereof and their high resistance.

The prestressing allows eliminating the deformation component based on the structure of the mesh canvas 4, permanently reducing the deformational effect due to the three-dimensionality of said mesh canvas 4, and consists in subjecting the set of meshes 3 to a deformation process preferably under controlled tensile load in the longitudinal direction of the set of meshes 4, keeping the width A of the set of meshes 3 unchanged by restriction of movement in the transverse direction and support in the closing nodes 7; 7 'non-deformable and high strength, which allows to reduce the interior light of the turns 1 and the reduction of the radius of curvature of the vertices of the turns 1 that make up the mesh canvas 4, and causing an elongation AL in the main direction of the set of meshes 3 coinciding with the direction of application of the prestressing as shown in Figure 5, and finally obtaining a canvas of meshes 4 where said elongation AL has occurred and a reduction of the interior light of the turns 1 and of the radius of curvature of the vertices of said turns 1 with respect to the set of meshes 3. The length of the mesh canvases 4 has no limitation, this being generally of a variable nature and attending to specific needs, being generally established by the Maximum required weight of the mesh of meshes 4 obtained which is also capable of being subsequently rolled up for transfer.

In summary, the described manufacturing process allows, in any of its embodiments, to control the load - deformation properties of the manufactured mesh canvas 4 and thus obtain mesh canvases 4 of high strength and low deformation steel wire, under the application of external actions in any direction that subject the canvas of meshes to a flat tension state, being possible its use as a structural membrane. In addition, the closing nodes 7; 7 'obtained allow different meshes of meshes 4 to be joined together in a manner juxtaposed by the line of closure nodes 7; 7 ', thus being able to use mesh canvases 4 thus manufactured and joined together as a continuous structural membrane.

The process of the invention can be executed on a machine 100 as shown by way of example in Figure 6, which corresponds to a second aspect of the invention and will be detailed below. In this case, the procedure includes automatic intermediate stages, which correspond to:

- transporting the set of meshes 3 from a feeding unit 8 of the machine 100 where said set of meshes 3 is formed to a knotting unit 9 of said machine 100 where the side seals are made; Y

- transport the set of meshes 3 with the side closures from the knotting unit 9 to a stretching unit 10 of the machine 100, where the prestressing of said set of meshes 3 is performed and the mesh of meshes 4 is obtained. As mentioned a second aspect of the invention refers to a machine 100 in which the method according to the first aspect of the invention can be implemented in any of its embodiments.

The machine 100 comprises a wire feed unit 8 where individual turns 1 are formed, where the turns 1 are interwoven with each other two by two to generate meshes 2 of a given width A, and where successive meshes 2 are intertwined creating a set of meshes 3. The machine 100 further comprises a knotting unit 9, arranged next to the feeding unit 8, which receives the set of meshes 3 from the feeding unit 8 and where the two side seals are made simultaneously of the set of meshes 3, generating the closing nodes 7; 7 '; and a stretching unit 10 arranged next to the knotting unit 9, which receives the set of meshes 3 with the closing nodes 7; 7 'from said knotting unit 9 and where the prestressing treatment is carried out by stretching under controlled loading of the set of meshes 3, obtaining a canvas of meshes 4 with a width A equal to the width A determined of the set of meshes 3 but with a length greater than the length of said set of meshes 3 (AL greater). Units 8, 9 and 10 are arranged in series and synchronized with each other, such that said machine 100 is adapted to carry out the process of the first aspect of the invention in an automatic manner.

As shown in Figures 7a-7c, the knotting unit 9 comprises a plurality of twisting tools 12 for each of the lateral ends 30 of the mesh assembly 3, and a static structure 13 for each side of the assembly. meshes 3. The twisting tools 12 are attached to the corresponding structure 13, said twisting tools 12 having freedom of rotation on their own longitudinal axis 12a and simultaneous displacement towards the turns 1. Each twisting tool 12 comprises a head 18 which holds the ends 5 of the turns 1 sharing the same closing node 7; 7 ', a ring 16 by means of which a rotating horizontal axis 15 inserted in the ring 16 with an inner spiral 17 is fixed to the corresponding structure 13 to allow its torsion rotation on said ends 5 and its simultaneous longitudinal displacement out of the mesh assembly 3 without the possibility of retraction of the head 18, conferring a continuous pressure without the possibility of reducing it to the lateral end 30 in the direction of rotation and of the displacement that allows the knotting without the possibility that the deformation conferred to the ends of the wires 6 of the corresponding adjacent and intertwined turns 1 are reversed, the twisting tool 12 being adapted to cause a twist of up to 360 °, such that it is adapted to cause a twist of 360 ° (first embodiment of the process of the invention) or a 180 ° twist (second embodiment of the process of the invention).

The twisting tools 12 are therefore allowed longitudinal displacement to guarantee their approach to the lateral end 30 of the mesh set 3 and to continue with the outward movement of the mesh canvas while forming the closure knot. 7; 7 'corresponding, maintaining the pressure on said closing node 7; 7 'to not allow torsion to reverse (Figure 7b). The twisting tools 12 are coupled to a motor (not shown in the figures) by, for example, a gear system, the motor providing sufficient torque to cause the necessary twisting to each pair of wire tips 6 comprised in each knot of close 7; 7 'from the side end 30 of the mesh set 3.

The heads 18 of the twisting tools 12 allow the formation of the closing knot 7; 7 'as described above, and also allow the folding of the tips 6 towards the inside of the mesh assembly 3, the heads 18 comprising a cone-shaped or double wedge folding tool 18a, which can be pneumatically or mechanically actuated by example, which pushes the tips 6 towards the inside of the mesh set 3 and positions them parallel to the axis of the closing knot 7; Corresponding T (Figure 7c).

The knotting unit 9 further comprises a terminal (not shown in the figures) associated with each torsion tool 12, and more specifically to the head 18 of said torsion tool 12, for when the second embodiment of the machine 100 is implemented in the machine 100 First aspect of the invention. Once the tips 6 are folded, the knotting process is completed with an equivalent welding or joining phase, which is executed by means of the arrangement on the heads 18 that allow the folding of an analogous number of terminals to infer the welding. Said terminals fix the tips 6 of the ends 5 of the turns to the wires of the corresponding turns 1 by contacting the two wire strands with each other and passing a certain current that forms an arc and allows the joint of solidarity and resistance between they. In the machine 100, as mentioned once the side closures have been made, the set of meshes is transported to the stretching unit 10 where said set of meshes 3tal is stretched and as shown in Figure 5, obtaining a canvas of meshes 4 with an increase in its length (AL) but without reduction or variation in its width A, and with reduction of the interior light of the turns 1 and decrease in the radius of curvature of the vertices of said turns 1.

The means of transport used in the machine 100 to transport the set of meshes 3 from one unit to another may correspond to conventional means of transport that could be used by a person skilled in the art, so they are not detailed.

A mesh of meshes 4 obtained according to the process of the first aspect the invention or in the machine 100 of the second aspect the invention can be used, by itself or together with other canvases of analogous meshes 4, in different applications due to its undeformable characteristics already mentioned .

An example of application is as a structural support and pressure distribution membrane in a slope stabilization and protection system, combined with a bolt system, which fixes the canvas of meshes 4 (or mesh canvases 4) to the ground. The wire mesh canvases 4 will be sized according to the level of resistance required, defining the pitch of the loop 1 and the diameter and tensile strength of the steel wires that make it up, thus obtaining a structural membrane with a resistance level at a given traction and a controlled deformational behavior, obtained in the prestressing phase of the process by reducing the interior light of the turns 1 and reducing the radius of curvature of the vertices of said turns 1 of the mesh canvas 4, and allowing adjustment the structural membrane solution to be used to the ground support requirement.

When a mesh of meshes 4 (or of the arrangement of more than one canvas of meshes 4 of simple torsion steel wire) works as a structural membrane in a system of stabilization and protection of slopes, said canvas of meshes 4 must guarantee continuity in the transmission of the efforts of a canvas of meshes 4 to another canvas of meshes 4 when they are arranged adjacently and joined together, which is achieved by the existence of the closure knots 7; 7 'non-deformable that allow to transfer the efforts of some mesh canvases 4 to other mesh canvases 4, transferring the same to a bolt head by means of distribution plates or connecting plates, and, in some cases, cables and spirals of union, always with low levels of deformation of the canvas of meshes 4 and without opening or deformation of the closing nodes 7; 7 '. The connection of the different canvases of meshes 4 adjacent to each other to form a structural membrane of continuous support, is therefore carried out with connection elements that guarantee the transmission of stresses between a canvas of mesh 4 and the adjacent one and that both are held in solidarity. mesh canvases 4 with one another, preferably using a steel cable or other element that guarantees the strength of the connection.

In any case, the union between two canvases of adjacent meshes 4 by the corresponding lateral ends 30 with closure nodes 7; T is assured and guaranteed before the application of external actions that generate efforts in the mesh canvases 4, by the typology of the same as described in the present invention, since these are closing knots 7; 7 'non-deformable high strength, which guarantees that in the case of the use of a connecting element such as that described, the failure of the lateral end 30 does not occur due to opening of the closing nodes 7; 7 'under load.

The total distribution area thus obtained, by repetition of the joint described between canvases of adjacent meshes 4, must be braced throughout the perimeter of the land area to be stabilized. Internally, the structural membrane may be jointly connected to bolts 22 by means of connection elements 21; 23, with internal perforation to accommodate the bolt 22 and allow the support of a connecting nut 29, the assembly may or may not be reinforced by means of bracing 24, preferably horizontal, consisting of one or more cables to confer a higher level of support to the assembly and which will determine the geometric configuration of the connection element 21; 23. Depending on the type and arrangement of the bracing 24 and connecting elements 21; 23 to which the structural membrane is fixed to guarantee the efficient and continuous transmission of the efforts from it to the bolts 22 that connect it to the stable area of the land, the system achieved will have a behavior according to a geotechnical model that allows establishing the level of stabilizing support conferred to the unstable ground.

Thus, reference can be made to a stabilization system with punctual connection as shown in Figure 8, when the canvas of meshes 4 (or meshes of meshes 4 joined together), acting as a structural membrane, is bracing perimeter continuously and punctually fixed by means of at least one distribution plate 21 directly to the head of the bolts 22 in the inner zone thereof, with a density and arrangement thereof preferably to the triplet (not shown in the figures) and determined by the calculations Geotechnical stability of ground thrust.

Reference may also be made to a reinforced stabilization system when a canvas of meshes 4 (or meshes of meshes 4 joined together), acting as a structural membrane, is perimeter-mounted continuously and fixedly attached to the head of bolts 22 in the inner zone thereof by means of connecting plates 23 and horizontal reinforcement bracing 24, with a bracing line as shown in Figure 9 or with two bracing lines as shown in Figure 10, preferably high strength steel cables, which are placed longitudinally along the slope and evenly spaced thereon. Preferably, it is used for the connection of the reinforcement cables to the structural membrane as shown in Figures 9 and 10, spirals 25 of diameter steel wire and the same type of wire used for the manufacture of the canvas of meshes 4, with a step proportional to that of the canvas of meshes 4 to allow its connection in the exposed manner. Optionally, different mesh canvases 4 can also be connected to each other by using a steel cable or other element that guarantees the strength and continuity of the connection.

The different sectors of connection of the bracing to the structural membrane can be independent and alternated, providing solid unions that prevent, in the case of breakage of any connection, the transmission of the fault to the rest of the sectors.

This distribution surface, once installed, loaded and correctly attached to the ground as a structural membrane of a stabilization system, due to the low level of deformation that it presents when it is loaded by the action of the ground thrust, allows to obtain a system adequate to the levels of ground support requirements adapting the structural membrane to be used in terms of its geometry, strength of steel and wire diameter.

Another example of application is as a structural membrane used as a collection surface within a kit to contain mudflows or debris, soil thrusts and / or snow and protection against rockfalls and impacts, conveniently fixed to the support structure of the kit so that in the event of a force of thrust or an impact transfer the efforts generated on it to the structure of posts, cables and bolts to the ground without opening or deformation of the knots and with deformation control.

In general, the technology of wire mesh canvases 4 currently existing, in particular those known as simple twist and manufactured with different diameters and grades of steel, are applicable in general uses and cannot be used directly as structural membranes with resistant function where high resistance with low deformation is essential.

The mesh canvases 4 of the invention allow them to be subjected to external actions that produce a flat tension on them, but with low levels of deformation.

These structural membranes allow working conditions thereof, and in particular within their preferred use as a structural support and distribution membrane as part of a slope stabilization system, catchment surface of a mud flow containment kit or debris, snow thrusts and protection against rockfalls and impacts, or in general for any application in which a structural function is required, a controlled load-deformation behavior with low levels of deformation for high levels of load.

Claims

Procedure for the manufacture of steel wire mesh canvases, where a plurality of steel wires are acted upon to form a coil (1) of a given width (A) with each wire, different coils (1) are intertwined with each other. ) adjacent, two by two, to generate a mesh (2) of a given width (A), different meshes (2) are intertwined with each other, generating a set of meshes (3), a lateral closure is made at both lateral ends (30) of the set of meshes (3), and the set of meshes (3) is subjected to a prestressing treatment by stretching under controlled load in the direction perpendicular to the meshes.

(2), which coincides with the longitudinal direction of the set of meshes

(3), obtaining a mesh canvas

(4), characterized in that in the procedure, in addition, the two lateral closures of a set of meshes (3) are carried out simultaneously and each lateral closure is carried out by generating a plurality of closure knots (7, 7'), generating a closure knot (7; 7') for each mesh (2) and by lateral closure, and each closure knot (7; 7') being made by twisting one end (5) of one of the coils. (1) corresponding on one end (5') of the other corresponding coil (1) with an angle of rotation such that it allows maintaining some tips (6, 6') of said ends (5,

5') in the plane of the mesh (2), and by subsequently folding said tips (6, 6') towards the interior of the set of meshes (3).

Procedure according to claim 1, wherein the set of meshes (3) is generated in a feeding unit (8), and, in the procedure, said set of meshes (3) is automatically moved to a knotting unit (9) where the lateral closures of said set of meshes (3) are made simultaneously, generating the closure knots (7; 7'), and said set of meshes (3), with the lateral closures made, is automatically moved to a prestressing unit (10) where the prestressing of said set of meshes (3) is carried out, generating the mesh canvas (4) in said prestressing unit (10).

Procedure according to claims 1 or 2, wherein during the prestressing treatment of the set of meshes (3) the closing knots (7, 7') remain supported laterally, allowing only their simultaneous longitudinal displacement, obtaining a canvas of meshes ( 4) in which a longitudinal elongation (AL) has occurred and a reduction in the interior light of the turns (1) and of the angle of the vertices of said spirals (1) with respect to the set of meshes (3) while keeping their width (A) constant.

Procedure according to any of claims 1 to 3, wherein the angle of rotation of one end (5) of a coil (1) with respect to an end (5') of the other coil (V) of a mesh (2) to generate a closing knot (7) is 360°.

Procedure according to any of claims 1 to 3, wherein the angle of rotation of one end (5) of a coil (1) with respect to an end (5') of the other coil (V) of a mesh (2) to generate a closing knot (7') is 180°, and where the points (6,

6'), folded, are joined to the corresponding coil (1) by electrowelding or by another equivalent joining method.

Machine for the manufacture of steel wire mesh canvases, which comprises a wire feeding unit (8) where individual coils (1) are formed, where the coils (1) are intertwined with each other two by two to generate meshes (2) of a determined width (A) and where successive meshes (2) are intertwined with each other, creating a set of meshes (3), characterized in that it also comprises a knotting unit (9) arranged after the feeding unit ( 8), which receives the set of meshes (3) from the feeding unit (8) and where the two lateral closures of said set of meshes (3) are carried out simultaneously, generating the closing knots (7, 7') , and a stretching unit (10) arranged after the knotting unit (9), which receives the set of meshes (3) with the closing knots (7, 7') already made from said knotting unit ( 9) and where the prestressed treatment is carried out by stretching under controlled load of said set of meshes (3), obtaining a canvas of meshes (4), said units (8, 9, 10) being arranged in series and synchronized with each other.

Machine according to claim 6, wherein the knotting unit (9) comprises a twisting tool (12) for each of the closing knots (7,

7') and a fixed structure (13) for each lateral closure of the set of meshes (3), with all the twisting tools (12) associated with the same lateral closure of the set of meshes (3) attached to the structure (13). ) corresponding with freedom of rotation about its own transverse axis (12a) and with freedom of simultaneous transverse movement, each torsion tool (12) comprising a head (18) to hold a closing knot (7; 7'), a ring (16) fixed to the structure (13) corresponding, a transverse axis (12a), an internal spiral (17) to allow the torsional rotation of the torsion tool (12) on the ends (5) of the corresponding closing knot (7; 7') and its simultaneous longitudinal displacement towards the interior of the set of meshes (3) without the possibility of recoil of the head (18) of the twisting tool (12) and to impart a certain pressure to the corresponding closing knot (7; 7') in the direction of rotation and of the displacement that allows knotting without the possibility of the deformation conferred on the tips (6) of the ends (5) of the coils (1) that share said closing knot (7; 7') being reversed, the tool also being torsion bar (12) adapted to rotate a predetermined rotation angle of at least 360°.

8. Machine according to claim 7, wherein the head (18) of the twisting tools (12) comprises a cone or double wedge shape actuated pneumatically or mechanically to fold the tips (6) the ends (5) of the knot closure (7; 7') corresponding to the interior of the mesh canvas (4).

9. Machine according to claim 8, wherein the head (18) of the twisting tools (12) is adapted to cause the joining of said folded tips (6) to the mesh canvas (4), preferably by electrowelding.

10. Steel wire mesh canvas characterized in that it is manufactured with the procedure according to claims 1 to 5 and/or with the machine according to claims 6 to 9.

Flexible slope stabilization and protection system, characterized in that it comprises at least one mesh canvas (4) according to claim 10 as a structural membrane in a mechanical system where the manufacturing process allows controlling the level of deformation under possible external actions caused by thrusts. of the land. 12. Containment and protection kit against rock falls and impacts, characterized in that it comprises at least one mesh canvas (4) according to claim 10 as a collection surface with controlled deformation.