Tensioning device for applying tensioning to an elongated metal element, machine for manufacturing a reinforced metal metal comprising such a tensioning device and method

Abstract

A tensioning apparatus (200) is configured to apply tension to an elongated metal element (20) that is supplied to a knitting machine (10) for manufacturing a metal mesh (12) for geotechnical protection. The tensioning apparatus (200) comprises a tensioning device (228) having a set of drums (230) around which one or more coils of an elongated metal element to be placed in a tensioned state are wound. A tensioning member (250) is provided which holds the coil in contact with the drum (230) in such a way that the friction between the elongated metal element (20) and the drum (230) itself is adjusted to create a reaction force opposite the pulling action exerted by the knitting machine (10) which tends to unwind the elongated metal element (20) from the drum (230) of the tensioning device (228).

Description

Technical Field

[0001] This invention relates to protective or barrier metal mesh in the field of geotechnical engineering, for example, for constructing protective barriers to prevent rockfalls, avalanches, or snowfall; bark-like coverings for rock walls to suppress rockfall; three-dimensional stabilization of soil, steep slopes, dams, embankments, tunnels, and road structures; retaining walls for constructing embankments; protective banks for water bodies; weirs and other debris barriers for constructing along rivers, streams, and general hydraulic structures; gabions and other products made of metal mesh; and any other known geotechnical engineering applications.

[0002] This invention is specifically developed for tensioning devices for flexible, elongated metal elements supplied to machines used to manufacture protective or reinforcing metal meshes of the type described above. Background Technology

[0003] In geotechnical engineering, various types of barrier or protective metal mesh are known to be used. Of particular interest are woven metal meshes made of interlaced metal wires that form the mesh openings. At the so-called knots, the wires are twisted together in a unidirectional direction. Depending on the number of turns of the wires relative to each other at the knots, the mesh can be single-twisted, double-twisted, or triple-twisted. In known types of double-twisted meshes, the wires are twisted together in a clockwise or counterclockwise direction in each knot to form the mesh openings, which are typically hexagonal. These meshes can be used, for example, to form protective barriers against rockfalls or to impede snow or avalanches. In other cases, they are used to construct barrier or protective structures, such as gabions made of metal mesh, or soil-stabilizing structures, such as the known trade name Terramesh from Officine Maccaferri SpA. ® The products. The wires used to construct the net described above may have protective covers, for example, known zinc or zinc / aluminum based covers, referred to as Galfan. ® Or a plastic coating on a metal wire, such as, for example, the known trade name Polimac for Officine Maccaferri SpA. ® Polymer coverings.

[0004] It is also known to reinforce twisted-pair metal meshes using additional flexible elements and / or elements with greater strength than the other wires in the mesh. Examples of such meshes reinforced with ropes or wires of greater strength are described by the same applicant in WO2005 / 038143, WO2011 / 030316, and WO2018 / 146516. When using these meshes, for example, the known trade name SteelGrid HR from Officine Maccaferri SpA is mentioned. ® and MacArmour ® In products like this, it is particularly advantageous to make the flexible reinforcement elements (whether wire or metal rope) as straight as possible, so that when the net is impacted, the flexible reinforcement elements (whether wire or rope) will immediately taut before the other wires forming the net. Furthermore, the tighter the flexible reinforcement elements in the protective net, the closer the net width will be to the nominal production width. However, if the flexible reinforcement elements woven into the net are undulating, the tension of the flexible reinforcement elements under force will cause the net width to shrink, thus requiring more netting to cover the same surface area to be protected.

[0005] Various types of braking systems are known for supplying wire to various types of machines while maintaining proper and uniform tension. For example, it is known to apply a constant braking force to the wire by means of the supply rollers of a brake reel (from which the wire is drawn). Using this system can be difficult when manufacturing protective netting for the geotechnical engineering industry because the wire reels are very heavy and bulky, and it is also difficult to coordinate the braking systems of all reels to ensure that the tension of all reinforcing wires or ropes in the net is substantially the same. In other words, a net in which the various reinforcing wires or ropes are not evenly tensioned will exhibit a twisted and uneven form.

[0006] In other known systems, the tensioned wire passes through one or more small-diameter heavy-duty pulleys that apply specific friction to the wire, thus braking it. These systems are often complex, difficult to adjust precisely, and difficult to adjust in a way that ensures all reinforcing wires or ropes in the net experience the same constant and uniform tension. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art by providing a tensioning device for reinforcing wires or ropes supplied to a weaving machine for geotechnical engineering protection, wherein the tensioning device allows tension to be applied to the reinforcing wires or ropes supplied to the weaving machine. Another purpose is to ensure that the tension applied to the reinforcing wires and ropes of the metal mesh remains constant and uniform over a long period. Yet another purpose is to provide a simple, efficient, economical, and long-term reliable tensioning device.

[0008] These and other objectives are achieved by a tensioning device having the features indicated in the appended claims.

[0009] The present invention also relates to a machine and method for constructing a protective net having the features claimed below.

[0010] According to a first aspect, a tensioning device is described, configured to apply specific tension to an elongated metal element supplied to a weaving machine for manufacturing a metal mesh for geotechnical engineering protection. Hereinafter, the term "geotechnical protection" is intended to be understood to include all specific fields of application to which the invention relates, as indicated above. The tensioning device may include a tensioning apparatus with a set of rollers around which one or more coils of the elongated metal element to be tensioned are wound. The tensioning device also includes a tensioning member configured to keep the coil in contact with the rollers in such a way that friction between the elongated metal element and the rollers is adjusted. In this way, a reaction force is generated that acts opposite to the pulling action applied by the weaving machine, which tends to unwind the elongated metal element from the rollers of the tensioning apparatus. The elongated metal element tensioned by this tensioning device is thus a reinforcing element that remains more stretched relative to other elongated metal elements forming the mesh of the mesh.

[0011] Depending on the specific aspect, the rollers wound with slender reinforcing metal elements of the geotechnical protective netting are rotatable rollers. In particular, the rollers are all fixed to a rotatable tensioning shaft, which ensures that the rollers rotate synchronously, thereby applying uniform tension to all the slender reinforcing metal elements wound on the rollers.

[0012] Depending on specific aspects, the position of each roller can be adjustable along the longitudinal axis of the shaft, thus accommodating different configurations and measurement dimensions of the reinforced metal mesh. Not only can the position of the rollers on the tensioning shaft be adjusted, but rollers can also be added or removed as desired.

[0013] According to a preferred aspect, the rotatable tensioning shaft may be provided with a braking device configured to selectively decelerate and / or brake the rotation of the rotatable tensioning shaft with a specific force, thereby acting in opposition to the pulling action applied when the mesh weaving machine obtains elongated metal elements from a corresponding supply reel. The term "deceleration" is intended to be understood as indicating a reduction in speed, while the term "braking" is intended to be understood as indicating a slowing of speed so that it does not increase.

[0014] In a preferred but not limiting manner, the braking device may include at least one brake disc, which is coaxially mounted on the shaft. At least one brake caliper is also provided, which can be controlled to selectively clamp the brake disc, thereby braking and / or slowing the rotation of the shaft on which rollers are mounted. The brake may be of an automatic, semi-automatic, or manually actuated type.

[0015] According to various aspects, a machine for manufacturing reinforced metal mesh is described, the reinforced metal mesh comprising a plurality of metal wires interwoven with each other and interwoven with metal ropes to define the mesh openings of the mesh. Upstream of the weaving device, the machine may include a tensioning device of the type indicated above, configured to apply greater tension to the metal ropes supplied to the machine, thereby keeping the metal ropes more straight than the metal wires as the mesh openings of the reinforced mesh are formed.

[0016] According to another aspect, a method for manufacturing a metal mesh for geotechnical engineering protection is described, wherein metal wires are interwoven in a weaving machine, the metal wires are interwoven with metal ropes, and wherein the metal ropes are supplied to the weaving machine by applying a reaction force opposite to the pulling action of the metal ropes being supplied by the weaving machine. Preferably, the reaction force applied to the metal ropes is generated by friction of the metal ropes on a corresponding tensioning surface. According to another preferred aspect, the tensioning surface is defined by a cylindrical cover of a roller, around which some coils of the metal ropes are wound. Attached Figure Description

[0017] Additional features and advantages will become apparent from the following detailed description of preferred embodiments, given only by way of example and not limitation, and wherein:

[0018] Figure 1 is a view of a known machine used for weaving metal protective netting;

[0019] Figure 2 The image shows a detailed diagram of a known machine used for weaving a metal protective or suppressive net, which is provided with woven reinforcing ropes interwoven with the metal wires of the net.

[0020] Figure 3 It is applicable to, according to the present invention, to Figure 2 A plan view of a known machine supplying rope and metal wire rope tensioning device;

[0021] Figure 4 yes Figure 3 Enlarged images of the details; and

[0022] Figure 5 It is along Figure 3 The cross section of the marked plane VV. Detailed Implementation

[0023] In the following embodiments, features that allow for the implementation of the invention are described. The described features can be combined with each other in various ways and are not necessarily limited to the precise embodiments described in the drawings and related descriptions. In other words, those skilled in the art who read the following specification will know how to obtain information items that facilitate understanding how to implement one or more of the described features by combining one or more of the described features with one or more of the other described features, and the specific formulation of the specification, paragraphs, terms, or drawings does not constitute a limitation on the possibility of isolating one or more of the described and illustrated features without combining them with one or more of any other described and illustrated features. More specifically, in this specification, it should be understood that any combination of any two explicitly described features is explicitly described, even if these features are extracted individually from the specific context in which they can coexist or be combined with other different features. Given the ability and knowledge of those skilled in the art, they understand the possibility of functionally combining these features without functionally applying other different features. Unless otherwise specified, every and every element, component, device, system, part, or object described and illustrated in this specification must be understood as separately described and capable of being modified independently, and capable of being separated from and / or combined with any and every other element, component, device, system, part, or object described and illustrated. The materials, forms, and functions described and illustrated are not intended to limit the invention, but are merely set forth to allow those skilled in the art to understand and practice the invention according to preferred but non-exclusive embodiments.

[0024] Referring now to Figure 1, a known machine for manufacturing a metal protective or suppressive net 1 for geological structural applications is schematically shown. The machine includes a weaving mechanism 2 that provides alternating weaving of a series of metal wires supplied from a reel 3 with similar metal wires removed from a rod 4, these similar metal wires interwoven with the metal wires from the reel 3. The resulting net 3 (which may be a net with double-twisted hexagonal meshes) passes around a roller or beam 5 for subsequent winding into a roll 6. A development of the invention relates to a reinforced net in which several wires supplied from the reel 3 are replaced by wires with greater resistance, or more preferably by ropes or cables, which generally have a greater thickness and strength than the other metal wires forming the net.

[0025] The same applicant has described known schemes for constructing reinforcement nets in documents WO2005 / 038143, WO2011 / 030316 and WO2018 / 146516, which are incorporated herein by reference in their entirety in order to describe the characteristics of reinforcement nets and their manufacturing facilities.

[0026] Figure 2This is a partial cross-sectional perspective view of a portion of machine 10 used to manufacture protective netting 12, particularly metal protective netting for civil engineering applications, such as rockfall barriers, snow barriers, debris barriers for waterways, bark-like coverings, and other protective measures for steep rock slopes or terrain. More specifically, the protective netting 12 comprises an assembly of metal wires 14 interwoven to form a series of meshes 16. In the embodiment shown, the meshes 16 are approximately hexagonal. In the field of twisted pair metal mesh, the size of hexagonal mesh is generally known and standardized, although any type and kind of hexagonal mesh can naturally be constructed according to the configuration of machine 10. There is a given ratio between the width and height of the hexagonal mesh, which is generally (even in a non-limiting manner) a value between about 0.70 and about 0.85 in the field, for example, at least nominally about 0.75 (for 60mm × 80mm mesh), about 0.80 (for 80mm × 100mm mesh) and about 0.83 (for 100mm × 120mm mesh).

[0027] The metal wires 14 are arranged generally along their length in the preferred longitudinal direction of the protective mesh 12. The metal wires 14 are interwoven in wire interlacing sections 18, each section defined by a segment of the corresponding metal wire 14, which, for each interlacing section 18, are twisted together more than once in a single twisting direction (i.e., in a single clockwise or counterclockwise direction). This type of interlacing, defined as "twisted," is particularly resistive and stable, allowing for the production of protective meshes with robust and resistive mesh. Metal ropes 20, which have greater strength and preferably a larger diameter than the metal wires 14, are interlaced between the sets of metal wires 14 at predetermined, preferably regular intervals.

[0028] exist Figure 2 In embodiments of the reinforcing net, as with other reinforcing nets in the known literature described above, it is particularly advantageous that the metal rope 20 has the longest possible straight extension, although with slight undulations (relative to the undulating extension of the metal wire 14 forming the mesh of the reinforcing net 12), so that the metal rope 20 makes the main contribution to the strength of the protective net 12 after the protective net itself is impacted (e.g., by the impact of rock material from a landslide). Figure 2The example clearly shows that the metal wire 14 adjacent to the metal rope 20 is wound around the metal rope in a rope interlacing section 22, which is defined by segments of the metal wire 14 such that, for each rope interlacing section 22, these segments are re-twisted around the rope more than once in a unidirectional twisting direction (i.e., in a single clockwise or counterclockwise direction). The metal wire 14 is thus interlaced with the metal rope 20, which has lateral undulations relative to the preferred longitudinal direction. These lateral undulations are far less pronounced than the undulations of the metal wire 14, and specifically are almost straight or have very subtle undulations. Therefore, the metal wire 14 forms a so-called "semi-mesh" 24, which, in a protective net where the interlaced metal wires form a hexagonal mesh, can exhibit a semi-hexagonal characteristic form.

[0029] The protective net 12 is flexible and easy to transport. It can be constructed of metal wire 14, for example, made of ordinary steel with a diameter of 2mm to 3mm or larger, such as up to 4mm to 5mm. Naturally, the wire 14 can be completely or partially replaced by a thin metal rope with a diameter of, for example, approximately 2mm to 5mm, which is much smaller than the diameter of the largest and strongest metal rope 20.

[0030] The metal wire 14 and the maximum metal rope 20 may be covered by a protective cover, for example, a cover made of a plastic material that prevents or at least reduces corrosion of the metal wire and / or rope. The total outer diameter of the metal rope 20 (including the potential protective cover) is preferably from about 4 mm to about 6 mm and above, sometimes greater than 8 mm, for example, between 9 mm and 12 mm, preferably about 10 mm, naturally excluding typical dimensional tolerances in the metal rope manufacturing industry.

[0031] like Figure 2 As can be seen, machine 10 includes a roller or beam 32, which is mounted in a housing of the machine by means of a device not shown in the figure, thereby enabling it to rotate at a constant speed about the axis T of the roller or beam in the direction of arrow 34 in synchronization with the speed of the interlacing device of the wire 14. Radial protrusions or pins 38 protrude outward from the curved surface 36 of the roller. These pins are arranged in rows that extend in a direction parallel to the axis T and are spaced at equal angles. In each row, the pins 38 are arranged at a constant spacing, and two successive rows are staggered from each other by half a pitch in the axial direction. These pins are used to form a mesh with hexagonal openings and to block a portion of the formed mesh in the discharge direction of the machine.

[0032] The interlacing and / or interconnecting device for metal wires and ropes includes a series of pairs of first guide devices, spaced apart and coaxial, arranged in parallel rows relative to the axis of the roller 32 on one side of a plane of symmetry tangent to the cylindrical periphery of the beam 32. The pairs of guide members are arranged in a radial plane relative to the beam, and the pitch of the pairs of guide members is the same as the pitch of the pin 38. The interlacing and / or interconnecting device for metal wires and ropes also includes a series of pairs of second guide devices, spaced apart and coaxial, arranged on the other side of the plane of symmetry tangent to the roller 32. Each pair of second guide devices is arranged mirror-image of one pair of first guide devices relative to the plane of symmetry. The pairs of first and second guide devices can be moved simultaneously by half a pitch in an alternating manner along opposing directions parallel to the axis of the roller 32. During use, the rotation of the guide device around its axis creates the interlacing of the wires, while the paired first and second guide devices move in opposite directions parallel to the axis of the roller 32 to create hexagonal meshes. The interlacing devices move in a way that is naturally coordinated with the movement of the beam 32, thereby implementing the overall weaving of the net.

[0033] More specifically, two pairs of bars 40, 42 and 44, 46 are arranged below the roller 32. The two pairs of bars are parallel to the axis T and serve as supports for the rotatable semi-cylindrical bodies 60, 62, 64, 66. The function of the semi-cylindrical bodies is to twist the wires and ropes together in pairs to produce the net 12.

[0034] Bars 40, 42 and 44, 46 have a cross-section with a U-shaped profile rotated 90°. The bars are positioned in pairs such that the corresponding open edges of the U face each other and lie in a vertical plane of symmetry tangent to the periphery of roller 32; bars 40 and 42 form an upper pair, and bars 44 and 46 form a lower pair. Naturally, the terms "upper" and "lower" indicate... Figure 2 The arrangement of the bars in the embodiment is shown. However, in practice, it is not excluded that these bars can be arranged differently, for example, as shown in the example. Figure 2 As shown, the wire and rope slide primarily in the horizontal and vertical directions. More generally, the "upper" bar is downstream of the corresponding "lower" bar in the working direction, regardless of the height of the "upper" bar.

[0035] The pairs of bars 40, 42 and 44, 46 are supported by elements 50, 52, 54, 56, which form part of the fixed base of machine 10. Furthermore, these bars can move in a direction parallel to the axis T. The upper bars 40, 42 are similar to the bars 44, 46 of the lower bar pair. At the edge of each bar 40, 42, 44, 46, a semi-cylindrical seat with its axis perpendicular to the axis T is formed, and each semi-cylindrical seat receives a corresponding semi-cylindrical rotatable body 60, 62, 64, 66. The distance between each seat and its adjacent seat on the same bar is substantially equal to the distance between pins 38.

[0036] The semi-cylindrical rotatable body 62 received in the upper bar 42 is aligned with the semi-cylindrical rotatable body 66 of the lower bar 46, and each semi-cylindrical rotatable body has a corresponding through hole 72, 76, the axis of the through hole being parallel to the axis of the corresponding semi-cylindrical rotatable body. The through holes 72, 76 are also aligned. The metal wire 14 to be supplied to the forming mesh passes through the through holes 72, 76, as described in more detail below.

[0037] In the desired location area where the rope 20 is inserted into the net 12, upper semi-cylindrical rotatable bodies 160, 162 and lower semi-cylindrical rotatable bodies 164, 166 are provided. These rotatable bodies are preferably of a different type than the rotatable bodies used for the passage of the wire 14 and allow ropes with a diameter larger than the wire 14 to pass through.

[0038] Below each semi-cylindrical body 60, 160 supported by the upper bar 40, a cylindrical container 90 can be installed, which holds a predetermined length of helically wound wire 14. The wire 14 exits the cylindrical container 90 at the top, passes through a through-hole 72, and is supplied to a web-making machine for forming a web. During use, the cylindrical container 90 rotates around the adjacent wire 14 or around the rope 20.

[0039] Pairs of bars 40, 42 and 44, 46 are connected to a moving mechanism that allows two bars 42, 46, one above the other, and two bars 40, 44, one above the other, to simultaneously translate in the same direction parallel to the axis T of the roller 32, but with relative orientations. The moving mechanism is configured such that each semi-cylindrical body carried by the same bar can translate—from a position of the first semi-cylindrical body facing the bar it faces, to a second position of the semi-cylindrical body facing a second semi-cylindrical body adjacent to the first semi-cylindrical body. Furthermore, the semi-cylindrical rotatable bodies are connected by racks (such as...) Figure 2The visible racks 100, 102 are connected to a rotating mechanism that rotates the semi-cylindrical rotatable body in pairs so that two adjacent wires 14 interweave or twist the wires 14 with the rope 20, thereby creating twisted portions to gradually define the mesh of the protective net 12.

[0040] To tension the rope 20, a tensioning device 200 is provided, positioned upstream of the machine used to form the net, between the machine itself and the supply reels of the wire 14 and rope 20. The tensioning device 200 is fixed to the ground to withstand the forces applied to the wire 14 and rope 20, as will be better understood in the description below. The tensioning device 200 includes an inlet area 202 and an outlet area, into which the wire 14 and rope 20 are supplied, and from which they exit for supply to the machine 10. Figure 3 A specific configuration of the tensioning device 200 as viewed from above is shown. Arrow A indicates the supply direction of the wires 14 and ropes 20 from the supply reel to the machine for forming the net. In this specific configuration shown (considered merely an exemplary and not limiting form of the invention), 11 ropes 20 are arranged, spaced apart in groups of three adjacent wires 14. Naturally, the invention can be modified and adapted to suit any other type of supply configuration of wires 14 and ropes 20. For example, the number of wires 14 and / or ropes 20 can differ from that shown, because the number of adjacent wires 14 spaced apart by the ropes 20 can be different, and it is not necessary to use the same number of wires 14 for separation, even though a regular configuration of spacing between the ropes is preferred to provide uniformity of a particular performance level across the entire width of the finished product.

[0041] In the inlet area 202, the tensioning device 200 is provided with an inlet comb 206 mounted on a support 218. The teeth 208 of the inlet comb 206 separate the wire 14 and rope 20 from each other and align them at a predetermined spacing. The inlet comb 206 consists of a series of rods 212, which are preferably vertical and fixed to transverse bars 214. Tubes 216 for reducing friction between the wire 14 and rope 20 on the teeth 208 are rotatably and movablely mounted on the rods 212.

[0042] Downstream of the inlet comb 206, in a state where it is mounted on the same support 218, an inlet deflection roller 220 is arranged. This inlet deflection roller is rotatable and movable on the support 222 and redirects the wire 14 and rope 20 downward from the top of the inlet area 202 (i.e., where the outlet area 204 is located). An outlet comb 224, similar to the inlet comb 206, is provided in the outlet area. Downstream of the outlet comb 224, an outlet deflection roller 226, similar to the inlet deflection roller 220, is installed. The wire 14 and rope 20 are supplied from the outlet deflection roller to the lower portion of the machine 10 and, where applicable, further redirected by one or more other deflection rollers to rise again to face the cylindrical container 90, as described above. Figure 2 As shown.

[0043] In the section between the inlet deflection roller 220 and the outlet deflection roller 226, the wire 14 travels in a straight line without any obstruction. However, in the same section between the inlet and outlet deflection rollers 220 and 226, the rope 20 is associated with a tensioning device 228, which is configured to apply a specific additional tension to the rope. The tensioning device 228 includes an assembly of rollers 230 around which several coils (preferably two or three coils) of the rope 20 are wound. Lateral shoulders 232 are provided on the sides of the rollers 230, defining cylindrical covers 234 on which the coils of the rope 20 are wound. The rope 20 is held in a position aligned with the rollers 230 by guide wings 233. The cylindrical covers of the rollers 230 may be treated or covered with a material that increases the friction of the rope 20. The rollers 230 are mounted on a tensioning shaft 236, which is rotatable on a support 238. Preferably, in addition to arranging supports at the ends of the tension shaft 236, supports 238 are also arranged in the middle section of the tension shaft to prevent deflection of the tension shaft under the load applied by the tension of the ropes 20. The rollers 230 are fixed to the tension shaft 236 in an adjustable position along its axis, reflecting the number and position of the ropes 20 used to manufacture a particular product. As indicated above, the specific example shown in the figures has 11 evenly distributed ropes 20, and therefore 11 rollers 230, which are also evenly distributed along the tension shaft 236. Naturally, the number of ropes and corresponding rollers can vary based on the type of mesh to be constructed, for example, based on the width of the mesh and the spacing between one rope and another.

[0044] A brake assembly 240 is mounted at one of the two ends of the tensioning shaft 236. This brake assembly is configured to brake the rotation of the tensioning shaft 236, which is caused by the movement of the rope 20 pulling the roller 230, which is fixedly engaged with the tensioning shaft 236, thereby applying a predetermined tension to the rope 20 due to friction of the rope on the roller 230. The brake assembly 240 may include a brake disc 242, which is coaxially fixed to the end of the tensioning shaft 236. A brake caliper 244 (e.g., a pneumatic, hydraulic, or electric brake caliper, and manually actuated where applicable) may be actuated to clamp the wall of the brake disc 242 as desired, thereby acting in opposition to the rotation of the tensioning shaft 236 and thus to the rotation of the roller 230 (on which the rope 20 is wound) in order to dynamically tension the rope 20 itself. The clamping force of the brake caliper 244 may be fixed and predetermined, or it may be automatically adjustable to maintain a constant tension in the rope 20. To automatically adjust the braking of the tension shaft 236 via the brake assembly 240, an electronic control system (not shown) can be used. This electronic control system can receive signals, for example, indicating the rotational speed of the tension shaft 236 or the torsional force experienced by the tension shaft, and thereby adjust the clamping force of the brake caliper 244 on the brake disc 242. The actuation of the brake can be automatic, semi-automatic, or manual.

[0045] The tensioning device 200 also includes a tensioner 250 that acts on the rope 20 upstream of the tensioning device 228 to maintain a specific clamping of the loops provided at the rope 20 onto the drum 230. Figure 5 As shown more clearly, each rope 20 passes through a corresponding tensioner 250, which functions by redirecting the straight path of the rope 20 to a greater or lesser extent. The rope 20 passes between a set of fixed idler pulleys 252 and a set of opposing movable idler pulleys 254. In the exemplary embodiment shown, three fixed idler pulleys 252 are provided, mounted on a fixed support 256, having parallel axes of rotation aligned one after another at predetermined intervals along the sliding direction of the rope 20. Two movable idler pulleys 254 are also provided, mounted on a movable support 258, having parallel axes of rotation aligned along the sliding direction of the rope 20. The axes of the two movable idler pulleys 254 are intersected with the axes of the fixed idler pulleys 252, such that when the movable support 258 approaches the fixed support 256, the rope 20 is redirected from a straight configuration and forced to bend, thereby creating more or less noticeable undulations around the opposing idler pulleys 252, 254. The movement of the movable support 258 and the fixed support 256 toward and apart from each other can be achieved manually, for example, by rotating the screw-type adjustment member 260, or automatically by pneumatic, hydraulic or electrical control.

[0046] To create the reinforcing mesh, wire 14 and rope 20 are supplied to machine 10 from corresponding reels, allowing the wire and rope to pass through a tensioning device. Wire 14 passes through the space allocated to the wire between the two teeth 208 of the inlet comb 206, bends above the inlet deflection roller 220, and continues to extend in a straight line—until it passes through the corresponding space between the two teeth of the outlet comb 224—before bending upwards, it wraps around the outlet deflection roller 226 in order to be supplied to machine 10.

[0047] The rope 20 also passes through the space allocated to the rope between the two teeth 208 of the inlet comb 206 and bends over the inlet deflection roller 220 so as to be guided toward the outlet comb 224 and the deflection roller 226 in the same manner as the wire 14. However, before reaching the outlet comb 224, the rope 20 is first introduced into the tensioner 250 so as to be wound continuously on the roller 230 of the tensioning device 228 with a certain number of coils, preferably two or three coils.

[0048] When machine 10 is put into operation to weave metal wire 14 and rope 20 and construct a reinforcing mesh, the machine obtains the required quantity of wire and rope by pulling them from the corresponding reels. Unwinding the wire 14 from the reels proceeds without any particular obstruction, while unwinding the rope 20 involves a tensioning effect applied to the rope primarily by tensioning device 228. Specifically, machine 10 encounters specific resistance when pulling the rope 20 to construct the reinforcing mesh. This resistance encountered when obtaining the rope 20 keeps the rope taut during weaving, ensuring that the rope remains nearly straight during the formation of the mesh, as... Figure 2 As shown. The tension of rope 20 depends to a large extent on the friction applied to the cylindrical cover of roller 230 during the sliding of rope 20. This friction depends not only on the material of the rope 20, but also, particularly, on the tension of the loops on roller 230 and the degree to which the movement of roller 230 is slowed or braked relative to the sliding of rope 20. The clamping of the loops of rope 20 on roller 230 is primarily regulated by tensioner 250, while the relative speed of the rope sliding on roller is regulated by the braking intensity applied by braking assembly 240 to the rotation of tensioning shaft 236.

[0049] Naturally, while keeping the principles of the invention unchanged, the form and construction details of the embodiments can vary considerably from those described and shown, without departing from the scope of the invention.

Claims

1. A tensioning device for applying tension to an elongated metal element (20) supplied to a weaving machine for manufacturing a metal mesh for geotechnical engineering protection, the tensioning device comprising a tensioning apparatus (228) having a set of rollers (230), a coil or more coils of the elongated metal element to be placed in a tensioned state being wound around the rollers, a tensioning member (250) keeping the coil in contact with the rollers in such a way that friction between the elongated metal element and the rollers is adjusted to generate a reaction force opposite to the pulling action applied by the weaving machine, the pulling action tending to unwind the elongated metal element from the rollers of the tensioning apparatus (228).

2. The tensioning device according to claim 1, wherein, The roller (230) is rotatable.

3. The tensioning device according to claim 2, wherein, All of the rollers (230) are fixed to a rotatable shaft (236) so that they can rotate synchronously.

4. The tensioning device according to claim 3, wherein, The position of each roller (230) is adjustable along the longitudinal axis of the shaft.

5. The tensioning device according to claim 3 or 4, wherein, The rotatable shaft (236) is provided with a braking device (240) which is configured to selectively decelerate and / or brake the rotation of the shaft.

6. The tensioning device according to claim 5, wherein, The braking device (240) includes at least one brake disc and at least one brake caliper coaxially mounted on the shaft, the brake caliper being controllable to selectively clamp the brake disc, thereby braking and / or decelerating the rotation of the shaft on which the roller is mounted.

7. A machine for manufacturing a reinforced metal mesh (12) comprising a plurality of metal wires (14) interwoven with each other and interwoven with metal ropes (20) to define the mesh of the reinforced metal mesh, the machine comprising, upstream of a weaving device, a tensioning device according to any one of the preceding claims, the tensioning device being configured to apply tension to the metal ropes (20) supplied to the machine, thereby keeping the metal ropes more straight than the metal wires (14) when forming the mesh of the reinforced metal mesh.

8. A method for manufacturing a reinforcing metal mesh (12) for geotechnical engineering protection, wherein, In the braiding machine, metal wires (14) are interwoven with each other and with metal ropes (20), and the metal ropes are supplied to the braiding machine by applying a reaction force opposite to the pulling action of the braiding machine on the metal ropes being supplied.

9. The method according to claim 8, wherein, The reaction force applied to the metal rope (20) is caused by the friction of the metal rope on the corresponding tensioning surface.

10. The method according to claim 9, wherein, The tensioning surface is defined by a cylindrical cover (234) of a roller (230), around which one or more coils of the metal rope (20) are wound.

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