Screening slat made of wood composite for a lattice fence

Abstract

The invention relates to a screening slat made of wood composite with a brushed surface finish, which has a constant cross-section and comprises two faces (20a; 20b) which are mainly planar, which each define a main frontal plane (P) and which are located on either side of a frontal plane (PI) at mid-thickness of the screening slat, and two longitudinal edges (20c; 20d) which connect the two faces (20a; 20b) of the screening slat, without protruding from the main frontal planes (P). The screening slat has asymmetry characteristics.

Description

[0001] COMPOSITE WOOD-BASED SCREEN BLADE FOR LATTICE FENCE

[0002] Technical field

[0003] The present invention relates to the field of rigid or flexible mesh fences comprising screening slats.

[0004] Prior art

[0005] A mesh fence is made from mesh panels that can be rigid or flexible. A rigid mesh panel is generally made from a mechanically welded assembly of vertical and horizontal rigid metal wires or bars. A flexible mesh panel is a flexible and most often rollable mesh.

[0006] Lattice panels, whether rigid or flexible, have openwork mesh, and therefore have the disadvantage of not blocking the view through the fence. For this reason, various variants of screening slats (also commonly called screening slats) have been developed to date, which can be inserted vertically into a rigid lattice panel and / or a flexible lattice panel. The screening slats can be rigid, semi-rigid or flexible and can be positioned vertically in the same plane in the rigid or flexible lattice panel, being juxtaposed or slightly spaced from each other.

[0007] One type of privacy screen that is popular for its aesthetic and strength features is a privacy screen made from composite wood.

[0008] Composite wood is known as a mixture of wood fibers and thermoplastic polymer(s), for example polyethylene (PE), and preferably high-density polyethylene (HDPE), polypropylene (PP) or polyvinyl chloride (PVC). Composite wood gives the privacy slat a modern and natural look and provides a warm finish similar to solid wood. However, unlike solid wood, privacy slats made from composite wood require little maintenance and are very resistant, particularly to climatic conditions.

[0009] A composite wood privacy slat can advantageously be manufactured by mono-extrusion followed by cutting each extruded slat to the desired length.

[0010] A composite wood-based screening blade can also be manufactured by coextrusion, so as to obtain a composite wood screening blade covered on at least each of its two faces with a layer of thermoplastic polymer.

[0011] In both cases (mono-extrusion or co-extrusion), in order to give them a more natural and less plastic appearance, the two faces of the extruded wood composite screening slats are preferably and usually brushed in the direction of their length, in order to obtain a brushed surface finish resulting in a structured and non-smooth effect on both faces.

[0012] European patent application EP 3 249 139 describes a particular variant of a screening blade for a trellis fence, which can advantageously be manufactured by extrusion. The blade also has a through hole near its upper end to allow it to be attached.

[0013] French patent application FR 2 945 064 describes another particular variant of a screening blade for a trellis fence comprising at its upper end a retaining stop which is transverse and protrudes from one of its two faces. Due to the presence of this retaining stop, this screening blade cannot be manufactured by extrusion, but must for example be manufactured by injection molding, which compared to extrusion significantly reduces the production rate and significantly increases production costs.

[0014] European patent application EP 3660 244 describes another particular variant of a screening blade for a lattice fence comprising two opposite longitudinal edges in the form of longitudinal ridges projecting from one of the two faces of the screening blade. In one variant, these two longitudinal ridges respectively comprise two transverse notches intended to cooperate with a retaining wedge positioned on the lattice panel of the fence. This screening blade can be manufactured by extrusion. However, the projecting longitudinal ridges detract from the aesthetics of the screening blade and, above all, are in practice difficult to reconcile with brushing the face of the screening blade from which they project.

[0015] When examining a screening slat made of composite wood, both sides of which have been brushed, there is usually no significant visual difference to the naked eye between the two sides of the screening slat. However, it was nevertheless possible to observe, after installing a trellis fence composed of several screening slats, similar for example to those described in the aforementioned European patent application EP 3249 139, made of composite wood and brushed on both sides, that each side of the trellis fence most often had a non-uniform visual appearance that was detrimental to the aesthetics of the trellis fence, and in particular had different shades of color that were visible to the naked eye.

[0016] Objective of the invention

[0017] The invention aims to propose a new screening blade based on composite wood for trellis fencing, which can be manufactured by extrusion (mono-extrusion or co-extrusion), both sides of which have a brushed surface finish and which makes it possible to reduce, and preferably eliminate, the aforementioned homogeneity defects.

[0018] Summary of the invention

[0019] The invention thus relates to a screening blade based on composite wood for a trellis fence. The screening blade has a constant cross-section and comprises two faces which are mainly flat, each of which defines a main frontal plane (P), and which are located on either side of a frontal plane (P1) at mid-thickness of the screening blade, and two longitudinal edges which connect the two faces of the screening blade, without projecting from the main frontal planes (P). Both faces have a brushed surface finish and the occulting blade has at least one of the asymmetry characteristics (a) or (b): (a) the cross-section of the occulting blade is asymmetrical with respect to the frontal plane (P1) at mid-thickness of the occulting blade or (b) the cross-section of the occulting blade is asymmetrical with respect to a sagittal plane (P2) at mid-width of the occulting blade.

[0020] In this text, the terms "occultation blade" are synonymous with the terms "occultation slat" also commonly used for this type of product.

[0021] In this text, the term "composite wood" refers to any mixture comprising wood fibres and one or more thermoplastic polymers, the wood fibres preferably, but not exclusively, being in the majority (i.e. at least 50% by weight). The mixture may also include additives or adjuvants.

[0022] In this text, the term "mainly flat face" means a face of which the greater part of its surface is flat and defines said main frontal plane, and preferably of which at least 90% of its surface is flat and defines said main frontal plane.

[0023] In this text, the "cross section" of the occultation blade can also and indifferently be designated by the synonymous terms "cross section" of the occultation blade.

[0024] In this text, the terms "transverse profile" of a longitudinal edge or face of the occulting blade designate the cross-sectional (or equivalently cross-sectional) profile of the longitudinal edge or face of the occulting blade in a plane perpendicular to the direction of the length of the occulting blade.

[0025] The brushed surface finish on both sides of the screening blade gives them a textured, rather than smooth, appearance. This brushed surface finish is usually obtained by a mechanical, post-extrusion surface treatment of both sides of the screening blade, such as brushing both sides of the screening blade to a greater or lesser depth and in the length direction of the blades.

[0026] Without being bound by this interpretation, the aforementioned homogeneity defects, which have been observed with the prior art brushed composite wood screening blades, would be caused by differences between the brushed effects of the two faces of the screening blade.

[0027] In the invention, the aforementioned asymmetry characteristic (a) or (b) advantageously makes it possible to differentiate at least the two faces of the occulting blades.

[0028] In particular, this differentiation of the two faces advantageously allows an operator, during the surface finishing step, by brushing the two faces or equivalent, to pass the occulting blades into the brushing machine with the same orientation of the faces of the occulting blades.

[0029] This differentiation of the two faces also allows the installer of the mesh fence to install the screening slats with the same orientation of the faces of the screening slats. Thus, the faces of the screening slats corresponding to each face of the mesh fence have the same brushed effect. This thus makes it possible to reduce, and preferably in most cases to eliminate, the aforementioned homogeneity defects.

[0030] More particularly, the occulting blade of the invention may comprise the following additional and optional features, each additional and optional feature being able to be combined with any of the other technical features of the occulting blade:

[0031] - The occulting blade has both characteristics (a) and (b).

[0032] - The transverse profile of at least one of the longitudinal edges is asymmetrical with respect to the frontal plane (P1) at mid-thickness.

[0033] - The transverse profile of each longitudinal edge is asymmetrical with respect to the frontal plane (P1) at mid-thickness.

[0034] - the transverse profiles of the two longitudinal edges are identical and symmetrical to each other with respect to a sagittal plane (P2) at mid-width.

[0035] - The occulting blade comprises at least characteristic (a) and said longitudinal edge with asymmetrical transverse profile or each longitudinal edge with asymmetrical transverse profile comprises a chamfer at the junction with one of the two blade faces.

[0036] - The occulting blade comprises at least the characteristic (a) and said longitudinal edge with asymmetrical transverse profile or each longitudinal edge (20c; 20d with asymmetrical transverse profile forms a bevel.

[0037] - The width (e) of the chamfer or bevel-shaped transverse profile, measured in the direction (X) of the width of the concealing blade, is less than or equal to the thickness (E) of the concealing blade.

[0038] - The transverse profiles of the two longitudinal edges are different.

[0039] - The occulting blade has at least characteristic (b) and one of the longitudinal edges is rounded.

[0040] - The occulting blade has at least characteristic (a) and the two faces of the occulting blade have different transverse profiles.

[0041] - One of the two faces has a longitudinal and eccentric groove.

[0042] - Both faces are completely flat and parallel.

[0043] - The Concealment Blade has a through hole near one of its two ends.

[0044] - The through hole is centered relative to a sagittal plane (P2) at mid-width.

[0045] - The privacy slat is made of composite wood and is mono-extruded.

[0046] - The occulting blade is solid. - The occulting blade has a honeycomb structure.

[0047] - Composite wood comprises wood fibers mixed with at least one thermoplastic polymer chosen from the following group: polyethylene (PE), high-density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC).

[0048] - The thickness (E) of the occultation blade is between 2mm and 6mm.

[0049] The invention also relates to a method for manufacturing a plurality of the aforementioned screening blades in which at least one composite wood material is extruded through an extrusion die and cutting operations are carried out in order to obtain semi-finished screening blades having the same length, the extrusion die being adapted to obtain semi-finished screening blades which comprise said characteristic (a) and / or said characteristic (b) and which comprise a downstream end and an upstream end, and in which the two faces of the semi-finished screening blades are brushed in the direction of their length so as to give them a brushed surface finish.

[0050] Preferably, the brushing operation is carried out by introducing, between at least two brushes, all the semi-finished occulting blades by the same upstream or downstream end and by orienting the faces of the semi-finished occulting blades in the same direction relative to the brushes, and all the semi-finished occulting blades are passed between the brushes and oriented so as to brush the two faces of the semi-finished occulting blades longitudinally.

[0051] More particularly in a particular implementation of this method, a through hole is drilled near the same downstream or upstream end of the occulting blades, and preferably centered relative to a sagittal plane at mid-width of the occulting blade, this drilling operation being able to be carried out before or after brushing the semi-finished occulting blades.

[0052] The invention also relates to an assembly for installing a trellis fence comprising several screening blades mentioned above or obtained by implementing the above manufacturing method, the screening blades preferably having identical cross-sections.

[0053] More particularly, said assembly of the invention may comprise the following additional and optional characteristics, each additional and optional characteristic being able to be combined with any of the other technical characteristics of said assembly:

[0054] - Said assembly comprises at least one rigid or flexible mesh panel.

[0055] - Each occulting blade comprises a through hole near one of its two ends and preferably centered relative to a sagittal plane (P2) at mid-width, and said assembly comprises at least one assembly part comprising one or more projecting attachment elements which are capable of being passed through the through hole of the occulting blades.

[0056] - Said assembly comprises at least one finishing rail adapted to be fitted onto the top of the lattice panel so as to assemble with the lattice panel at least one assembly part placed on the upper wire or bar of the lattice panel.

[0057] Another subject of the invention is a method of installing a trellis fence in which at least one trellis panel is placed vertically and several screening blades referred to above or obtained by implementing the above manufacturing method are positioned vertically in the trellis panel, the screening blades having the same orientation.

[0058] The invention also relates to the use of the aforementioned screening blades or those obtained by implementing the aforementioned manufacturing method, for screening at least part of a trellis fence panel.

[0059] Brief description of the drawings Other characteristics and advantages of the invention will appear more clearly on reading the detailed description below of several variant embodiments in accordance with the invention, which detailed description is given as non-limiting and non-exhaustive examples of the invention and with reference to the appended drawings in which:

[0060] - Figure 1 is an overall view showing an example of a lattice fence comprising a lattice panel partially concealed by means of three concealing blades in accordance with a first variant embodiment of the invention.

[0061] - Figure 2 is an enlargement of the lattice fence of Figure 1 showing, in exploded view, the upper part of the lattice panel with the three screening blades of Figure 1, a strip for hanging the screening blades and a finishing rail.

[0062] - Figure 3 is an isometric perspective view of a concealing blade, before brushing, which conforms to said first embodiment variant.

[0063] - Figure 3A is a front view of the occulting blade of Figure 3.

[0064] - Figure 3B is an enlargement, in front view, of the upper part of the occulting blade of Figure 3A.

[0065] - Figure 3C is a top view of the occulting blade of Figure 3A.

[0066] - Figure 4A is a front view of a concealing blade, before brushing, in accordance with a second variant embodiment of the invention.

[0067] - Figure 4B is an enlargement, in front view, of the upper part of the occulting blade of Figure 4A.

[0068] - Figure 4C is a first example in top view of the occulting blade of Figure 4A.

[0069] - Figure 4D is a second example in top view of the occulting blade of Figure 4A. - Figure 5A is a front view of an occulting blade, before brushing, in accordance with a third variant embodiment of the invention.

[0070] - Figure 5B is an enlargement, in front view, of the upper part of the occulting blade of Figure 5A.

[0071] - Figure 5C is a top view of the occulting blade of Figure 5A.

[0072] Figure 6A is a front view of a concealing blade, before brushing, in accordance with a fourth variant embodiment of the invention.

[0073] - Figure 6B is an enlargement, in front view, of the upper part of the occulting blade of Figure 6A.

[0074] - Figure 6C is a top view of the occulting blade of Figure 6A.

[0075] - Figure 7A is a front view of a concealing blade, before brushing, in accordance with a fifth variant embodiment of the invention.

[0076] - Figure 7B is an enlargement, in front view, of the upper part of the occulting blade of Figure 7A.

[0077] - Figure 7C is a first example in top view of the occulting blade of Figure 7A.

[0078] - Figure 7D is a second example in top view of the occulting blade of Figure 7A.

[0079] Figure 8A is a front view of a concealing blade, before brushing, in accordance with a sixth variant embodiment of the invention.

[0080] - Figure 8B is an enlargement, in front view, of the upper part of the occulting blade of Figure 8A.

[0081] - Figure 8C is a top view of the occulting blade of Figure 8A.

[0082] - Figure 9A is a front view of a concealing blade, before brushing, in accordance with a seventh variant embodiment of the invention.

[0083] - Figure 9B is an enlargement, in front view, of the upper part of the occulting blade of Figure 9A.

[0084] - Figure 9C is a first example in top view of the occulting blade of Figure 9A.

[0085] - Figure 9D is a second example in top view of the occulting blade of Figure 9A

[0086] - Figure 10 illustrates the main steps of a first variant embodiment of a method for manufacturing a screening blade according to the invention.

[0087] - Figure 11 illustrates the main steps of a second variant embodiment of a method for manufacturing a screening blade according to the invention.

[0088] Detailed description

[0089] Example of lattice fence - Fig.1 to Fig.3

[0090] Figure 1 shows a particular example of a lattice fence. This lattice fence comprises a lattice panel 1 with openwork mesh, into which are vertically threaded screening blades 2A conforming to a first variant embodiment of the invention.

[0091] In Figure 2, the occulting blades 2A are aligned in the horizontal X direction by being coplanar and slightly spaced from each other.

[0092] Alternatively, particularly with other types of openwork mesh panels, the 2A screening blades may be aligned in the horizontal X direction by being coplanar and juxtaposed edge to edge.

[0093] In the particular variant of figure 1, this lattice panel 1 is more particularly constituted by a rigid mechanically welded assembly of horizontal bars or metal wires 10, 10', 10” and vertical bars or vertical metal wires 11.

[0094] More particularly in this particular embodiment, each vertical bar or wire 11 comprises two V-shaped folds 11a, 11b respectively at the top and bottom. This type of panel with fold(s) may also comprise a single V-shaped fold or more than two V-shaped folds.

[0095] Figures 3A to 3C, 4A to 4D, 5A to 5C, 6A to 6C, 7A to 7D, 8A to 8C, 9A to 9D show different variants of extruded and semi-finished occulting blade, i.e. before brushing both faces of the occulting blade.

[0096] 2A occulting blade before brushing - Characteristic (a) - Fig.3 and Fig.3A to Fig.3C

[0097] The 2A privacy board is a solid, slender board made from composite wood.

[0098] This 2A screening blade is manufactured by mono-extrusion of a composite wood material through an extrusion die. The cross-section (Fig. 3C) of this 2A screening blade is thus constant and corresponds to the cross-section of the extrusion die through which the material is pushed.

[0099] In another variant, the screening blade can also be manufactured by coextrusion of a composite wood material and at least one additional thermoplastic polymer making it possible, in a manner known per se, to form a protective and / or decorative layer on the surface of the screening blade.

[0100] The occulting blade 2A extends longitudinally (Y axis) over a length L1, and has a transverse width L2 (X axis) and a constant thickness E (Z axis).

[0101] In the context of the invention, the thickness E of the composite wood screening blade of the invention may be more or less significant, the screening blade of the invention being able to be rigid, semi-rigid or flexible.

[0102] The thickness E of the occultation blade is preferably, but not necessarily, between 2mm and 6mm.

[0103] The occulting blade 2A has two opposite faces 20a and 20b (Fig.3C) and two opposite longitudinal edges 20c and 20d.

[0104] The two faces 20a and 20b (Fig.3C) are entirely flat and parallel and therefore have in a transverse plane (plane perpendicular to the longitudinal direction Y corresponding to the length of the blade) a rectilinear transverse profile. These two flat faces 20a, 20b are located on either side of the frontal plane P1 at mid-thickness.

[0105] With reference to Figure 3C, the two flat faces 20a and 20b each define a main frontal plane P. The occulting blade 2A makes it possible to define a frontal plane P1 at mid-thickness of the blade (i.e. plane which is parallel to the frontal plane P, which extends longitudinally in the direction (Y) of the length of the blade, which extends laterally in the direction (X) of the width of the blade and which is centered on the thickness E of the blade) and a sagittal plane P2 at mid-width of the blade (i.e. plane which is perpendicular to the frontal plane P1, which extends longitudinally in the direction (Y) of the length of the blade and which is centered on the width L2 of the blade).

[0106] The two opposite longitudinal edges 20c and 20d extend (Fig. 3A) over the entire length L1 of the occulting blade. The two longitudinal edges 20c, 20d connect the two faces 20a and 20b of the occulting blade, without projecting from the main frontal plane P of each face 20a and 20b.

[0107] The cross-section of the occulting blade 2A (or in other words the straight section of the occulting blade) in a transverse plane perpendicular to the longitudinal direction Y which corresponds to the length of the blade, is asymmetrical with respect to the frontal plane P1 [i.e. characteristic (a)].

[0108] In this particular embodiment, this asymmetry is obtained thanks to two longitudinal edges 20c and 20d, which are identical and symmetrical to each other with respect to the sagittal plane P2 at mid-width, but whose transverse profile (Fig. 3C) is asymmetrical with respect to the frontal plane P1 at mid-thickness.

[0109] More particularly in this variant, each longitudinal edge 20c and 20d comprises a broken transverse profile consisting of a rectilinear part 200 which extends from the face 20b and perpendicular to the frontal plane P1, and which extends to the other face 20a by a chamfer 201 conferring said asymmetry to the longitudinal edge.

[0110] The width e (Fig.3C) of each chamfer 201, measured in the direction (X) of the width of the blade, is less than the thickness E of the concealing blade.

[0111] Preferably, this chamfer 201 forms an angle A1 of 45° relative to the frontal plane P1.

[0112] In another variant, this angle A1 may be an acute angle having a value other than 45°. Nevertheless, it is preferable that the width e (Fig.3C) of each chamfer 201 is less than or equal to the thickness E of the occulting blade.

[0113] With reference to Figure 2, the screening blades 2A are mounted on the lattice panel 1 with the same orientation of their faces, that is to say with their faces 20a oriented and visible from the same side of the lattice fence and their faces 20b oriented and visible from the other side of the lattice fence. This orientation of the screening blades is made possible thanks to the aforementioned asymmetry of the longitudinal edges 20c and 20d, (that is to say in this particular variant thanks to their chamfers 201), which allows the installer to easily differentiate the two faces 20a and 20b from each other.

[0114] The aforementioned asymmetry of the longitudinal edges 20c and 20d also allows the manufacturer to differentiate the two faces 20a and 20b from each other upstream, in particular when implementing the surface finishing step (brushing) of the two faces.

[0115] These chamfers 201 are discreet and do not detract from the aesthetics of the mesh fence. On the contrary, the symmetry of the two chamfers 201 with respect to the sagittal plane P2 helps to improve the aesthetics of the screening blade.

[0116] With reference to Figures 3, 3A and 3B, the occulting blade 2A preferably comprises a through hole 21 which is made in the vicinity of its upper end and which is preferably centered relative to the sagittal plane P2 at mid-width. This through hole 21 can have any section and can for example be of circular section or oblong section.

[0117] With reference to Figure 2, the occulting blades 2A are fixed in the upper part, to the lattice panel 1, by means of a rectilinear assembly part 3 in the form of a strip. This assembly part 3 comprises a plurality of attachment elements 31 projecting on one of its faces 30a and aligned in the direction (X) of the width of the blades while being spaced apart.

[0118] Each of the attachment elements 31 more particularly has the shape of a hook. In another variant, a attachment element 31 may have another shape, and in particular the shape of a cylindrical lug.

[0119] The assembly part 3 is placed on the upper bar or wire 10” of the lattice panel 1. Each screening blade is hooked onto one of the hooking elements 31 passed through the through hole 21 of the screening blade 2A. The hooking element 31 thus makes it possible to hold said screening blade vertically.

[0120] Once the occulting blades 2A are threaded onto the lattice panel 1 and attached to the assembly part 3 which is placed on the lattice panel 1, a finishing rail 4 is fitted onto the top of the lattice panel 1 and onto the assembly part 3, so as to assemble the assembly part 3 with the lattice panel 1, as described in more detail in European patent application EP 3249 139, to which reference may be made.

[0121] Independently and in addition to its function of attaching the occulting blade 2A to the assembly part 3, and due to its eccentric longitudinal position (Y direction), the through hole 21 also serves as a foolproofing device by allowing the two ends (upper and lower) of the occulting blade 2A to be differentiated from one another.

[0122] Other examples of occulting blades 2B to 2G in accordance with the invention will now be described.

[0123] Concealing blade 2B before brushing - Characteristic (a) - Fig.4A to Fig.4D The concealing blade 2B of figures 4A to 4C differs from the concealing blade 2A previously described in that (Fig.4C) the two longitudinal edges 20c and 20d each form a bevel 202 connecting the two faces 20a and 20b and oriented at an angle A1 relative to the frontal plane P1 at mid-thickness.

[0124] The cross-section of the occulting blade 2B is thus asymmetrical with respect to the frontal plane P1 [i.e. characteristic (a)], the rectilinear transverse profile of each longitudinal edge in the shape of a bevel 202 being asymmetrical with respect to the frontal plane P1 at mid-thickness.

[0125] Preferably, for aesthetic reasons, these two bevels 202 are symmetrical to each other with respect to the sagittal plane P2 at mid-width, and their angle A1 is more preferably equal to 45.

[0126] In another variant, the angle A1 may be an acute angle having a value other than 45°. However, it is preferable that the angle A1 is less than or equal to 45° so that the width e (Fig.4C) of each longitudinal edge 20c and 20d in bevel, measured in the direction (X) of the width of the blade, is less than or equal to the thickness E of the occulting blade.

[0127] Referring to Figure 4C, optionally, each junction between the face 20b and each longitudinal edge 20c, 20d in the shape of a bevel is a sharp edge, as is each junction between the other face 20a and each longitudinal edge 20c, 20d in the shape of a bevel.

[0128] In another variant, such as that illustrated in Figure 4D, each junction between the face 20b and each longitudinal edge 20c, 20d in the form of a bevel is an edge which can be rounded (radius of curvature R).

[0129] In the same way as for the chamfers 201 of the screening blade 2A, the two longitudinal beveled edges allow the installer to easily differentiate the two faces 20a and 20b from one another, and thus allow him to install the screening blades 2B in the lattice panel 1 with the same orientation of their faces 20a and 20b. The two longitudinal beveled edges also allow the manufacturer upstream to differentiate the two faces 20a and 20b from one another, in particular during the implementation of the surface finishing step (brushing) of the two faces.

[0130] 2C occulting blade before brushing - Characteristic (b) - Fig.5A to Fig.5C

[0131] The occulting blade 2C of Figures 5A to 5C differs from the occulting blade 2A previously described in that the cross-section (Fig. 5C) of the blade is symmetrical with respect to the frontal plane P1 at mid-thickness, but is asymmetrical with respect to the sagittal plane P2 at mid-width [i.e. characteristic (b)].

[0132] More particularly, this asymmetry is obtained by means of two longitudinal edges 20c and 20d which each have a transverse profile symmetrical with respect to the frontal plane P1, but whose transverse profiles are different.

[0133] More particularly, in this example, the longitudinal edge 20c is rounded and has a curved profile centered and symmetrical with respect to the frontal plane P1 and more particularly in the shape of an arc of a circle. The longitudinal edge 20d is a straight edge whose transverse profile is rectilinear and perpendicular to the frontal plane P1.

[0134] The different profiles of the two longitudinal edges 20c and 20d allow the installer to differentiate them from one another and thus allow him to install the screening blades 2C in the lattice panel 1 with the same orientation of their longitudinal edges 20c and 20d, the curved longitudinal edges 20c being all oriented for example to the left (or to the right) when looking at one of the faces of the lattice fence. This same orientation of the longitudinal edges thus allows the screening blades 2C to be installed in the lattice panel 1 with the same orientation of their faces 20a and 20b. The different profiles of the two longitudinal edges 20c and 20d also allow the manufacturer upstream to differentiate the two faces 20a and 20b from one another, in particular during the implementation of the surface finishing step (brushing) of the two faces.

[0135] 2D occulting blade before brushing - Characteristics (a) and (b) - Fig.6A to Fig.6C

[0136] The 2D occultation blade of Figures 6A to 6C differs from the previously described 2A occultation blade in that (Fig. 5C) the cross-section of the blade is asymmetrical with respect to the frontal plane P1 at mid-thickness [i.e. characteristic (a)] and is also asymmetrical with respect to the sagittal plane P2 at mid-width [i.e. characteristic (b)].

[0137] More particularly, this double asymmetry is obtained on the one hand thanks to a longitudinal edge 20c whose transverse profile (Fig. 6C) is asymmetrical with respect to the frontal plane P1 at mid-thickness and on the other hand by having two longitudinal edges 20c and 20d which have different transverse profiles.

[0138] More particularly, in this example, the longitudinal edge 20c is identical to the longitudinal edge 20c of the occulting blade 2A and has the same chamfer 201 and the longitudinal edge 20d is a straight edge identical to the longitudinal edge 20d of the occulting blade 2C.

[0139] In another similar variant, the transverse profile of the longitudinal edge 20d could also be asymmetrical with respect to the frontal plane P1, provided that the transverse profiles of the longitudinal edges 20c and 20d are different.

[0140] This double asymmetry has the advantage of allowing the manufacturer of the occulting blades as well as the installer to differentiate not only the two faces 20a and 20b from each other, but also to differentiate the two ends of the occulting blades, before the through hole 21 is drilled in the occulting blade and / or without it being necessary to make a through hole 21 in the occulting blade.

[0141] More particularly, this double asymmetry allows the manufacturer to handle the occulting blades and to introduce them into a surface finishing machine, such as a brushing machine, by checking and ensuring more easily that all the occulting blades are introduced with the same orientation of their faces 20a and 20b relative to the surface finishing machine and by being introduced into the surface finishing machine always by the same end of the blade.

[0142] 2E occulting blade before brushing - Characteristics (a) and (b) - Fig.7A to Fig.7C

[0143] Like the 2D occultation blade, the cross-section of the 2E occultation blade of Figures 7A to 7C is (Fig.7C) asymmetrical with respect to the frontal plane P1 at mid-thickness [i.e. characteristic (a)] and is also asymmetrical with respect to the sagittal plane P2 at mid-width [i.e. characteristic (b)].

[0144] More particularly, this double asymmetry is obtained on the one hand thanks to a longitudinal edge 20c whose transverse profile (Fig.7C) is asymmetrical with respect to the frontal plane P1 at mid-thickness and on the other hand by implementing two longitudinal edges 20c and 20d which have different transverse profiles.

[0145] More particularly, in this example, the beveled longitudinal edge 20c is identical to the longitudinal edge 20c of the occulting blade 2B and the longitudinal edge 20d is a straight edge which is identical to the longitudinal edge 20d of the occulting blade 2C.

[0146] With reference to Figure 7C, optionally, the junction between the face 20b and the longitudinal beveled edge 20c is a sharp edge, as is the junction between the other face 20a and the longitudinal beveled edge 20c.

[0147] In another variant, such as that illustrated in Figure 7D, the junction between the face 20b and the longitudinal beveled edge 20c is an edge which can be rounded (radius of curvature R).

[0148] 2F occulting blade before brushing - Characteristics (a) and (b) - Fig.8A to Fig.8C

[0149] Like the 2D occultation blade, the cross-section of the 2F occultation blade of Figures 8A to 8C is asymmetrical (Fig.SC) with respect to the frontal plane P1 at mid-thickness [i.e. characteristic (a)] and is also asymmetrical with respect to the sagittal plane P2 at mid-width [i.e. characteristic (b)].

[0150] More particularly, in this variant, each longitudinal edge is symmetrical with respect to the frontal plane P1 and the two longitudinal edges are identical and symmetrical to each other with respect to the sagittal plane P2.

[0151] The above-mentioned double asymmetry [characteristics (a) and (b)] is obtained in this variant by a longitudinal and eccentric groove 203 which is made in one 20a of the two faces of the occulting blade 2F.

[0152] In this variant, the two faces 20a and 20b are flat with the exception only of this groove 203, the flat parts of each face 20a and 20b, on either side of this groove 203, defining the main frontal plane P.

[0153] Optionally, this groove 203 has an inverted V-shaped triangular cross-sectional profile and is as wide (L3) as it is deep (E1). In another variant, the groove 203 could be deeper (E1) than wide (L3) or conversely wider than deep.

[0154] 2G concealing blade before brushing - Characteristics (a) and (b) - Fig.9A to Fig.9D

[0155] The occulting blade 2G of figures 9A to 9C differs from the occulting blade 2F only by the geometry, in the shape of an inverted U, of the transverse profile of the longitudinal and eccentric groove 203' which is produced in one 20a of two faces of the occulting blade 2G.

[0156] In Figure 9C, the groove 203' is as wide (L3) as it is deep (E1).

[0157] In Figure 9D, groove 203' is deeper (E1) than it is wide (L3).

[0158] In another variant, the groove 203' may be wider (L3) than deep (E1).

[0159] Manufacturing processes of the occulting blades - Fig.10 and Fig.11

[0160] With reference to Figure 10, the manufacture of the occulting blades 2A to 2G is carried out in a first step (step S1) by extrusion of a composite wood material or by coextrusion of a composite wood material and at least one thermoplastic polymer through an extrusion die whose passage section of the material is identical to the transverse profile (Figure 3C, 4C, 4D, 5C, 6C, 7C, 7D, 8C, 9C or 9D) of the occulting blade before brushing 2A, 2B, 2C, 2D, 2E, 2F or 2G

[0161] Then, immediately at the exit of the extrusion die and in continuity with the extrusion step, successive transverse cuts are made in the usual manner (step S2) so as to form semi-finished (unbrushed) occulting blades of length L1. The cuts can be straight and perpendicular to the direction of the length of the blades or can possibly be inclined, for example at 45°, so as to obtain beveled edges at both ends of the blades.

[0162] These semi-finished occulting blades can be stored temporarily for later performance, possibly at another manufacturing site, of subsequent S3 and S4 finishing operations,

[0163] Preferably, in the case of occulting blades having a single asymmetry characteristic (a) or (b), the semi-finished blades are stored in such a way that it is possible to subsequently differentiate, for each occulting blade, its downstream end which is the first outlet from the extrusion die, from its other upstream end which is the last outlet from the extrusion die. This differentiation can be achieved by temporarily storing the semi-finished occulting blades by orienting them in the same direction. This differentiation can also be achieved by applying to each semi-finished occulting blade a temporary distinctive mark, such as for example an erasable chalk line or a removable self-adhesive pad, making it possible to identify the downstream end (or the upstream end) of each occulting blade.

[0164] This temporary storage with orientation of the semi-finished occulting blades or this temporary marking of the semi-finished occulting blades is useless in the case of occulting blades presenting the two asymmetry characteristics (a) and (b).

[0165] Then, with reference to Figure 10, (Step S3) each semi-finished blade is drilled in order to make the through hole 21 in the vicinity of the same downstream (or upstream) end for all the occulting blades. Finally, the semi-finished occulting blades are introduced (step S4) into a brushing machine which makes it possible to produce, in the lengthwise direction of the blades, a more or less deep brushed surface finish on the two faces 20a and 20b of the blades. This brushing operation is known. Once brushed, the two faces 20a and 20b of the occulting blade have, in a manner known per se, a brushed surface finish, which gives them a rough, less plastic and more natural appearance.

[0166] The brushing machine may, for example, comprise at least two brushes which are rotating and motorized. Each brush comprises, in a conventional manner, a brushing insert, for example made of hard radial steel bristles, which is capable of penetrating slightly and more or less deeply into one face of the concealing blades.

[0167] The semi-finished occulting blades 2 are introduced between the two brushes:

[0168] - with the same orientation of the faces 20a and 20b for all the blades, that is to say for example with the face 20a of each blade always oriented towards one of the brushes and with the other face 20b of the blade always oriented towards the other brush,

[0169] - and by always orienting the blades in the same direction relative to the working direction of the machine, that is to say by always introducing the blades into the machine from the same downstream end (or respectively from the same upstream end).

[0170] The occulting blades are thus brushed longitudinally on each same face with the same brush and always with the same brushing direction, that is to say from their same upstream end (respectively downstream) to their other downstream end (respectively upstream). The faces 20a and 20b of the occulting blades, after brushing, are not smooth but are textured more or less deeply, each with a brushed finish which is not strictly identical from one face to the other for the same occulting blade.

[0171] Referring to Figure 11, the drilling step S3 can also be performed after the brushing step (S4).

[0172] In the context of the invention, the openwork mesh lattice panel is not necessarily rigid, but may also be semi-rigid or flexible. The assembly of the composite wood-based screening blades of the invention on a lattice panel may be carried out by any known means and is not necessarily carried out by means of the particular assembly part 3 and the rail 4 previously described. In particular, the screening blades do not necessarily have a through hole 21. The screening blades are preferably solid, as illustrated in the attached figures.

[0173] In other embodiments of the invention, the extrusion die can be designed, in a manner known per se, to manufacture screening blades with an internal honeycomb structure, which makes it possible to save material for the manufacture of a blade.

Claims

CLAIMS 1 . A composite wood-based screening slat for a trellis fence, said screening slat has a constant cross-section and comprises two faces (20a; 20b) which are mainly planar, each of which defines a main frontal plane (P) and which are located on either side of a frontal plane (P1) at mid-thickness of the screening slat, and two longitudinal edges (20c; 20d) which connect the two faces (20a; 20b) of the screening slat, without projecting from the main frontal planes (P), the two faces (20a; 20b) having a brushed surface finish and the screening slat having at least one of the following asymmetry characteristics: (a) the cross-section of the screening slat is asymmetrical with respect to the frontal plane (P1) at mid-thickness of the screening slat or (b) the cross-section of the screening slat is asymmetrical with respect to a sagittal plane (P2) at mid-width of the occultation blade.

2. An occulting blade according to claim 1 in which (a) the cross-section of the occulting blade is asymmetrical with respect to the frontal plane (P1) at mid-thickness of the occulting blade and (b) the cross-section of the occulting blade is asymmetrical with respect to a sagittal plane (P2) at mid-width of the occulting blade.

3. Concealing blade according to any one of claims 1 or 2, in which the transverse profile of at least one (20c) of the longitudinal edges is asymmetrical relative to the frontal plane (P1) at mid-thickness.

4. Concealing blade according to claim 3, in which the transverse profile of each longitudinal edge (20c; 20d) is asymmetrical relative to the frontal plane (P1) at mid-thickness.

5. A concealing blade according to claim 4, wherein the transverse profiles of the two longitudinal edges (20c; 20d) are identical and symmetrical to each other with respect to a sagittal plane (P2) at mid-width.

6. Concealing blade according to any one of claims 3 to 5, in which at least (a) the cross-section of the concealing blade is asymmetrical relative to the frontal plane (P1) at mid-thickness of the concealing blade and in which said longitudinal edge (20c) with asymmetrical transverse profile or each longitudinal edge (20c; 20d) with asymmetrical transverse profile comprises a chamfer (201) at the junction with one (20a) of the two blade faces.

7. Concealing blade according to any one of claims 3 to 5, in which at least (a) the cross-section of the concealing blade is asymmetrical relative to the frontal plane (P1) at mid-thickness of the concealing blade and in which said longitudinal edge (20c) with asymmetrical transverse profile or each longitudinal edge (20c; 20d) with asymmetrical transverse profile forms a bevel (202).

8. Concealing blade according to claim 6 or 7, wherein the width (e) of the chamfer (201) or of the bevel-shaped transverse profile, measured in the direction (X) of the width of the concealing blade, is less than or equal to the thickness (E) of the concealing blade.

9. Concealing blade according to any one of claims 1 to 4, in which the transverse profiles of the two longitudinal edges (20c; 20d) are different.

10. A screening blade according to claim 9, wherein at least (b) the cross-section of the screening blade is asymmetrical relative to a sagittal plane (P2) at mid-width of the screening blade and wherein one (20c) of the longitudinal edges is rounded.

11. Concealing blade according to any one of claims 1 to 10, in which at least (a) the cross-section of the concealing blade is asymmetrical with respect to the frontal plane (P1) at mid-thickness of the concealing blade and in which the two faces (20a; 20b) of the concealing blade have different transverse profiles.

12. Concealing blade according to claim 11, in which one (20a) of the two faces comprises a longitudinal and eccentric groove (203 or 203').

13. Concealing blade according to any one of claims 1 to 12, in which the two faces (20a; 20b) are entirely flat and parallel.

14. Concealing blade according to any one of claims 1 to 13 and comprising a through hole (21) near one of its two ends.

15. A screening blade according to claim 14, wherein the through hole is centered relative to a sagittal plane (P2) at mid-width.

16. Concealment blade according to any one of claims 1 to 15, made of composite wood and mono-extruded.

17. A screening blade according to any one of claims 1 to 16, said screening blade being solid.

18. A screening blade according to any one of claims 1 to 16, said screening blade having a honeycomb structure.

19. A screening blade according to any one of claims 1 to 18, wherein the composite wood comprises wood fibers mixed with at least one thermoplastic polymer chosen from the following group: polyethylene (PE), high density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC).

20. Concealing blade according to any one of claims 1 to 19, and having a thickness (E) between 2mm and 6mm.

21. A method of manufacturing a plurality of screening blades according to any one of claims 1 to 20, in which at least one composite wood material is extruded (S1) through an extrusion die and cutting operations are carried out (S2) in order to obtain semi-finished screening blades having the same length (L1), the extrusion die being adapted to obtain semi-finished screening blades of which (a) the cross-section is asymmetrical with respect to the frontal plane (P1) at mid-thickness of the screening blade and / or of which (b) the cross-section is asymmetrical with respect to a sagittal plane (P2) at mid-width of the screening blade and which comprise a downstream end and an upstream end, and in which the two faces of the semi-finished screening blades are brushed (S4) in the direction of their length so as to give them a brushed surface finish.

22. Manufacturing method according to claim 21, in which the brushing operation is carried out by introducing, between at least two brushes, all the semi-finished occulting blades by the same upstream or downstream end and by orienting in the same direction the faces (20a; 20b) of the semi-finished occulting blades relative to the brushes, and all the semi-finished occulting blades are passed between the brushes and oriented so as to longitudinally brush the two faces (20a; 20b) of the semi-finished occulting blades.

23. Manufacturing method according to claim 21 or 22, in which a through hole (21) is drilled (S3) near the same downstream or upstream end of the occulting blades, and preferably centered relative to a sagittal plane (P2) at mid-width of the occulting blade, this drilling operation (S3) being able to be carried out before or after the brushing (S4) of the semi-finished occulting blades.

24. Assembly for installing a trellis fence comprising several screening slats according to any one of claims 1 to 20 or obtained by implementing the manufacturing method of any one of claims 21 to 23, the screening slats preferably having identical cross-sections.

25. Assembly according to claim 24, comprising at least one rigid or flexible mesh panel.

26. Assembly according to any one of claims 24 or 25, in which each occulting blade comprises a through hole (21) near one of its two ends and preferably centered relative to a sagittal plane (P2) at mid-width, and said assembly comprises at least one assembly part (3) comprising one or more projecting attachment elements (31) which are capable of being passed through the through hole (21) of the occulting blades.

27. Assembly according to claims 25 and 26 and comprising at least one finishing rail (4) adapted to be fitted on top of the lattice panel (1) so as to assemble with the lattice panel (1) at least one assembly part (3) placed on the upper wire or bar (10”) of the lattice panel.

28. Method for installing a lattice fence in which at least one lattice panel (1) is placed vertically and several screening blades according to any one of claims 1 to 20 or obtained by implementing the manufacturing method according to any one of claims 21 to 23 are positioned vertically in the lattice panel, the screening blades having the same orientation.

29. Use of occulting blades according to any one of claims 1 to 20 or obtained by implementing the manufacturing method according to any one of claims 21 to 23, to conceal at least part of a lattice fence panel.

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