Mesh and method of manufacture

Abstract

A mesh having a plurality of elongate bars connected to each other at a plurality of connections along their lengths. Each of the connections includes two link pieces with a cavity between them. A method of making a mesh is also provided and includes extruding a length of material to produce an extrusion with a plurality of bars that are connected by first and second portions of material. The first and second portions of material are spaced apart with cavities between them and the bars. The extrusion can be perforated in regions between the bars and expanded into a mesh.

Description

[0001] Mesh and method of manufacture

[0002] FIELD

[0003] This invention relates to a mesh and a method of manufacturing a mesh.

[0004] BACKGROUND

[0005] Meshes have many uses, for example in gratings, grilles, security barriers, decorative panels, and reinforcement for materials such as concrete or plastic. Meshes typically include several elongate pieces connected to each other. The elongate pieces may be bars, which are known as load bars.

[0006] Meshes can come in various sizes, and a given type of mesh may be manufactured to various sizes by selecting the desired lengths of the elongate pieces and / or number of elongate pieces used.

[0007] SUMMARY

[0008] According to one example embodiment there is provided a mesh having a first side and a second side, the mesh comprising: a plurality of elongate load bars; and a plurality of link pieces; wherein: each of the plurality of load bars is connected to an adjacent load bar at a respective plurality of connections along the load bars; each connection between the load bar and the adjacent load bar comprises first and second link pieces of the plurality of link pieces, each of the first and second link pieces being connected between the load bar and the adjacent load bar; and the first link piece is located towards the first side of the mesh and the second link piece is located towards the second side of the mesh such that there is a cavity defined between the first link piece, the second link piece, the load bar and the adjacent load bar.

[0009] In some examples, a plurality of openings are defined in the mesh, each opening being between a load bar and an adjacent load bar in a region between successive connections along the load bars.

[0010] In some examples, the load bars are solid bars.

[0011] In some examples, each load bar has wider portions towards the first and second sides of the mesh and a narrower region between the wider regions.

[0012] In some examples, the plurality of load bars includes two outermost load bars, each at an edge of the mesh, and one or more inner load bars, wherein each of the inner load bars is connected to a first adjacent load bar towards one edge of the mesh and a second adjacent load bar towards the other edge of the mesh such that the inner load bar is alternatingly connected to the first adjacent load bar and the second adjacent load bar along its length.

[0013] In some examples, the mesh further comprises a plurality of ribs running along the load bars at the first side.

[0014] In some examples, the ribs are knurled.

[0015] In some examples, the mesh is substantially flat at the second side.

[0016] In some examples, the mesh is an expanded mesh.

[0017] In some examples, the load bars and the link pieces are integrally formed.

[0018] In some examples, the mesh is formed from an extrusion.

[0019] In some examples, the mesh is made of metal.

[0020] In some examples, the mesh is made of aluminium. According to another example there is provided a method of manufacturing a mesh, the method comprising: a) extruding a length of material to produce an extrusion, the extrusion having: a first side; a second side; a plurality of bars extending along the length of the extrusion; a first portion of material connecting the plurality of bars, the first portion of material being located towards the first side of the extrusion; a second portion of material connecting the plurality of bars, the second portion of material being located towards the second side of the extrusion; and a plurality of cavities defined therein, each cavity being between the first portion of the material, the second portion of the material, and two of the bars; b) perforating the first portion of the material and the second portion of the material at a first plurality of locations between each pair of adjacent bars, leaving connections between each pair of adjacent bars at a second plurality of locations; and c) expanding the extrusion in a dimension transverse to the length of the bars to produce openings between adjacent bars at the first plurality of locations.

[0021] In some examples, perforating the first and second portions is performed by punching.

[0022] In some examples, punching comprises punching from the first side and the second side.

[0023] In some examples, expanding the extrusion is performed by stretching.

[0024] In some examples, the method further comprises knurling the first side of the extrusion. In some examples, the bars of the extrusion are solid bars.

[0025] In some examples, the material is metal.

[0026] In some examples, the material is aluminium.

[0027] It is acknowledged that the terms "comprise", "comprises" and "comprising" may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, these terms are intended to have an inclusive meaning - i.e., they will be taken to mean an inclusion of the listed components which the use directly references, and possibly also of other non-specified components or elements.

[0028] Reference to any document in this specification does not constitute an admission that it is prior art, validly combinable with other documents or that it forms part of the common general knowledge.

[0029] BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of embodiments given below serve to explain the principles of the invention.

[0031] Figure 1 is an isometric view of a mesh according to one example;

[0032] Figure 2 is an enlarged view of a detail of Figure 1;

[0033] Figure 3 is an isometric view of an extrusion according to one example;

[0034] Figure 4 shows three exemplary extrusion profiles;

[0035] Figure 5 is an isometric view of the extrusion of Figure 3 after perforation; and

[0036] Figure 6 is a plan view of the perforated extrusion of Figure 5. DETAILED DESCRIPTION

[0037] Figure 1 illustrates a mesh 1 according to an example embodiment.

[0038] The mesh 1 includes several load bars 2, only some of which are labelled in Figure 1. The load bars 2 are elongate and generally extend from one end 9 of the mesh to the other end 10. The load bars 2 include outermost load bars 2a and 2b at the edges 7 and 8 of the mesh, and inner load bars 2c, 2d and 2e between the outermost load bars 2a and 2b.

[0039] The load bars 2 are connected to each other at connections 3, only some of which are labelled in Figure 1. The connections 3 connect each load bar 2 to an adjacent load bar 2. For example, the load bar 2c is connected to the adjacent load bar 2d at several connections along its length. Only two of the connections, 3a and 3b, between the load bars 2c and 2d are labelled. Each of the inner load bars can be connected to two adjacent load bars, one at each side. For example, the load bar 2c is also connected to the load bar 2e, which is on the opposite side of it from the load bar 2d. Each inner load bar can be alternatingly connected to the adjacent load bar on one side and then the adjacent load bar on the other side. For example, the load bar 2c is connected to the load bar 2d at the connection 3a, to the load bar 2e at the connection 3c, to the load bar 2d at the connection 3b, and so on along its length. The outermost load bars 2a and 2b are each only connected to one adjacent load bar. The connections 3 will be described in more detail with reference to Figure 2, which is an enlargement of Detail A of Figure 1.

[0040] The mesh 1 has openings 4 formed in it. The openings 4 are provided in regions between adjacent load bars 2 where the load bars 2 are not connected to each other. The openings 4 may be offset from each other in the sense that one row of openings 4 at one side of a load bar 2 (e.g. between load bars 2c and 2e) are offset from openings at the other side of the load bar 2 (e.g. between load bars 2c and 2d). In some examples, the mesh 1 can be an expanded mesh. In these examples, the openings 4 may be formed by expanding a perforated material to open up the perforations.

[0041] The mesh 1 has a first side 5 and a second side 6. In the orientation shown in Figure 1, the first side 5 is the upper side and the second side 6 is the lower side. The mesh 1 may be used in this orientation when used as a grating or the like for walking on. The mesh may include grip-improving features such as ribs and / or knurling on the "upper" side, especially when it is intended to be walked on. However, the mesh 1 may be used in any suitable orientation depending on the application.

[0042] The mesh 1 may be made of any suitable material. In some examples, the mesh 1 may be made of metal. The metal may be aluminium. Aluminium may provide good strength-to-weight characteristics and be readily extrudable.

[0043] Turning to Figure 2, the connections 3 and certain features of the load bars 2 of Detail A are shown in more detail.

[0044] Each of the three connections 3 shown includes two link pieces 11 and 12. The link piece 11 is located "above" the link piece 12 in the orientation shown. In other words, the link piece 11 is located towards the first side 5 (labelled in Figure 1) and the link piece 12 is located towards the second side 6 (labelled in Figure 1). The link pieces 11 and 12 are spaced apart from each other along an axis running from the first side 5 to the second side 6. Between the two link pieces 11 and 12 and the connected load bars 2 is a cavity 13. As a result, the portion of the mesh 1 in the region of the connection 3 has a generally rectangular or "box" profile.

[0045] The provision of two links pieces 11, 12 in each connection may provide greater strength and stiffness than an equivalent mesh with only one link piece in the connection would have. For example, a connection with only an "upper" link piece approximately in the location of link piece 11 may be much more prone to bending under loads. The open profile of such a mesh in the region of its connections may not hold its shape as well as the closed, rectangular or "box" profile of the mesh 1. As can be seen in Figure 2, the load bars 2 can be solid bars, e.g. without cavities or the like though them. The load bars 2 provide much of the structural strength of the mesh 1 and it may be advantageous to provide more material to the parts of the mesh 1 where it will be most effective. In this case, this is in the load bars 2.

[0046] Ribs 14 can be provided along the load bars 2. In the example of Figures 1 and 2, the ribs 14 are on the first side 5 of the mesh 1, i.e. the "upper" side in the orientation shown. Ribs 14 may help to provide grip, which may be particularly advantageous when the mesh 1 is intended to be walked on with the first side 5 facing upwards. As best shown in Figure 2, the ribs 14 can be knurled. This may improve their ability to provide grip. The other side of the mesh, i.e. the "lower" second side 6 as shown in Figure 1, can be substantially flat. This may help the second side 6 of the mesh 1 to seat firmly and stably against a flat surface. In examples in which the mesh is placed with the second side 6 facing downwards, this may help the mesh 1 to seat firmly and stably on the surface underneath it.

[0047] The load bars 2 may have a "waisted" profile, being wider towards the first and second sides 5, 6 and narrower in the middle between the wider portions. For example, as shown in Figure 2 the load bars 2 are relatively narrow in the middle 15 and wider in the regions 16 and 17 "above" (i.e. towards the first side 5 of) and "below" (i.e. towards the second side 6 of) the middle 15.

[0048] In some examples, load bars 2 and the link pieces 11 and 12 may be integrally formed. In some examples, the mesh 1 can be formed from an extrusion, for example by perforating and expanding an extrusion.

[0049] Figures 3 to 5 show an exemplary extrusion 20 at different stages of the process of forming a mesh, such as the mesh 1 of Figures 1 and 2.

[0050] To produce a mesh, initially a length of material is extruded according to a suitable extrusion profile. As shown in Figure 3, the extrusion profile can be such that the extrusion 20 has a first side 25, a second side 26, bars 22 extending along the length of the extrusion 20, a first portion of material 31 located towards the first side 25 (i.e. an "upper" portion 31 in the orientation of Figure 3), and a second portion of material 32 located towards the second side 26 (i.e. a "lower" portion 32 in the orientation of Figure 3). The first and second portions 31 and 32 connect the bars 22 to each other such that each bar 22 is connected to the adjacent bar(s).

[0051] Any suitable material may be extruded to form the extrusion 20. In some examples, the extruded material is metal such as aluminium.

[0052] Cavities 33 are provided in the extrusion 20 between the first portion of material 31, the second portion of material 32, and adjacent bars 22. The extrusion 20 may be extruded using a porthole die, which allows hollow shapes to be extruded.

[0053] The extrusion 20 can have ribs 34 on one side. As shown in Figure 3, the ribs 34 are extruded without knurling, which is applied later.

[0054] The material can be extruded to any suitable length for the application. In some cases, the material may be extruded in standardised lengths to be later cut to desired lengths for specific applications. In other cases, the material may be extruded to the specific length(s) required for a particular application. The width of the extrusion 20 may be any suitable width by suitable design of extruder parts such as the extrusion die. Wider extrusions 20 may include more bars 22 and narrower ones may have fewer bars 22.

[0055] The extrusion 20 can also have various heights - height being the distance between the first side 25 and the second side 26. Figures 4A to 4C show three alternative extrusions 20', 20" and 20"' of different heights. In these examples, the height difference is a result of the bars 22', 22" and 22'" being different heights. The alternative extrusions 20', 20" and 20'" can be similar to each other in other respects.

[0056] Figure 5 shows the extrusion 20 after further processing. Specifically, the first and second portions of material (31 and 32 in Figure 3) are perforated between the bars 22 at multiple places along the lengths of the bars. One perforation is labelled 24 in Figure 5. Perforating the portions of material between adjacent bars 22 leaves connections 23, only one of which is labelled in Figure 5, between the adjacent bars 22. The perforated regions 24 may be offset from each other in the sense that one row of perforations 24 at one side of a bar are offset from perforations 24 at the other side of the bar 22. The connections 23 are formed from the remaining, unperforated regions of the first and second portions of material. Perforating may be performed by any suitable means. In one example, perforating is performed by punching. The punching may be performed from both sides of the extrusion (i.e. from side 25 and side 26 shown in Figure 3). The two sides may be punched one after the other. The punching may be done in a stepped manner along the extrusion 20, rather than punching the whole length at once. In alternative examples, perforating could be performed by other methods such as cutting, routing or milling.

[0057] The process of making the mesh can also include knurling the ribs 34. This may be performed before and / or after perforating the first and second portions. In some examples, the knurling process can also drive the extrusion along a processing line from a perforating location to an expanding location. In the example of Figure 5, the ribs 34 have been perforated.

[0058] Figure 6 shows the general layout of the bars 22, connections 23 and perforated regions 24 (only one of each being labelled in Figure 6) of the extrusion 20 after perforation. The next step of the process involves expanding the extrusion 20 in a dimension transverse to the length of the bars 22. In the example of Figure 6, the extrusion 20 can be expanded in the dimension indicated by axis 28. Expanding the extrusion 20 can be performed by any suitable method. In some examples, expanding is performed by stretching the extrusion 20. For example, the outer bars 22 of the extrusion 20 may be held, for example in jaws, clamps, hooks, or blocks with suitably shaped grooves for retaining the outermost bars, and pulled apart. In addition to expanding the extrusion 20 in transverse dimension (e.g. along axis 28), the extrusion may also be acted on in other directions to change or control its shape during or after expansion. For example, the expansion may be pulled in an axis generally aligned with the length of the bars 22 during or after pulling it in the axis 28. This may help ensure that the expanded mesh retains its approximately rectangular overall shape rather than narrowing in the middle (i.e. between edges 7 and 8 of Figure 1). The extrusion 20 may be held retained at its "upper" and "lower" sides (i.e. sides 25 and 26 of Figure 3) during pulling or it may be flattened after pulling. This may help to prevent or remove twisting, buckling, or bulging of the expanded mesh.

[0059] The length and / or width of the mesh formed by the process set out above may be partly controlled by the expansion step. For example, the amount by which the extrusion 20 is expanded in the transverse dimension (e.g. along axis 28) may be controlled to obtain a mesh with a desired width (width being the distance between the edges, e.g. edges 7 and 8 in the mesh 1 of Figure 1). Additionally or alternatively, the length of the resulting mesh may be controlled by the amount of expansion in the transverse dimension. This is because the extrusion 20 will shorten in the longitudinal dimension as it is expanded in the transverse dimension.

[0060] The expansion process causes the perforated regions 24 to open up and form openings between the bars 22 and connections 23. The bars 22 bend such that they are angled between the connections and follow reticulated or serpentine paths. The result of the perforation and expansion of the extrusion 20 is to turn it into a mesh, such as the mesh shown in Figure 1. Specifically:

[0061] • the bars 22 of the extrusion 20 form the load bars 2 of the mesh 1;

[0062] • the connections 23 left between the bars 22 after perforating the extrusion form the connections 3 of the mesh 1;

[0063] • the unperforated regions of the first and second portions of material 31 and 32 form, respectively, the first and second link pieces 16 and 17 of the of the mesh 1;

[0064] • the expanded perforated regions 24 form the openings 4 of the mesh 1; and • the remaining portions of the cavities 33 in the connections 23 form the cavities 13 of the mesh 1.

[0065] While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the Applicant's general inventive concept.

Claims

CLAIMS:

1. A mesh having a first side and a second side, the mesh comprising: a plurality of elongate load bars; and a plurality of link pieces; wherein: each of the plurality of load bars is connected to an adjacent load bar at a respective plurality of connections along the load bars; each connection between the load bar and the adjacent load bar comprises first and second link pieces of the plurality of link pieces, each of the first and second link pieces being connected between the load bar and the adjacent load bar; and the first link piece is located towards the first side of the mesh and the second link piece is located towards the second side of the mesh such that there is a cavity defined between the first link piece, the second link piece, the load bar and the adjacent load bar.

2. The mesh of claim 1 wherein a plurality of openings are defined in the mesh, each opening being between a load bar and an adjacent load bar in a region between successive connections along the load bars.

3. The mesh of claim 1 or claim 2 wherein the load bars are solid bars.

4. The mesh of any one of claims 1 to 3 wherein each load bar has wider portions towards the first and second sides of the mesh and a narrower region between the wider regions.

5. The mesh of any one of claims 1 to 4 wherein the plurality of load bars includes two outermost load bars, each at an edge of the mesh, and one or more inner load bars, wherein each of the inner load bars is connected to a first adjacent load bar towards one edge of the mesh and a second adjacent load bar towardsthe other edge of the mesh such that the inner load bar is alternatingly connected to the first adjacent load bar and the second adjacent load bar along its length.

6. The mesh of any one of claims 1 to 5 further comprising a plurality of ribs running along the load bars at the first side.

7. The mesh of claim 6 wherein the ribs are knurled.

8. The mesh of any one of claims 1 to 7 wherein the mesh is substantially flat at the second side.

9. The mesh of any one of claims 1 to 8 wherein the mesh is an expanded mesh.

10. The mesh of any one of claims 1 to 9 wherein the load bars and the link pieces are integrally formed.

11. The mesh of claim 10 wherein the mesh is formed from an extrusion.

12. The mesh of any one of claims 1 to 11 wherein the mesh is made of metal.

13. The method of claim 12 wherein the mesh is made of aluminium.

14. A method of manufacturing a mesh, the method comprising: a) extruding a length of material to produce an extrusion, the extrusion having: a first side; a second side; a plurality of bars extending along the length of the extrusion; a first portion of material connecting the plurality of bars, the first portion of material being located towards the first side of the extrusion;a second portion of material connecting the plurality of bars, the second portion of material being located towards the second side of the extrusion; and a plurality of cavities defined therein, each cavity being between the first portion of the material, the second portion of the material, and two of the bars; b) perforating the first portion of the material and the second portion of the material at a first plurality of locations between each pair of adjacent bars, leaving connections between each pair of adjacent bars at a second plurality of locations; and c) expanding the extrusion in a dimension transverse to the length of the bars to produce openings between adjacent bars at the first plurality of locations.

15. The method of claim 14 wherein perforating the first and second portions is performed by punching.

16. The method of claim 15 wherein punching comprises punching from the first side and the second side.

17. The method of any one of claims 14 to 16 wherein expanding the extrusion is performed by stretching.

18. The method of any one of claims 14 to 17 further comprising knurling the first side of the extrusion.

19. The method of any one of claims 14 to 18 wherein the bars of the extrusion are solid bars.

20. The method of any one of claims 14 to 19 wherein the material is metal.

21. The method of claim 20 wherein the material is aluminium.

Images