Patent Publication Number: US-2022220765-A1

Title: Structure for providing a physical or visual barrier

Description:
FIELD OF THE INVENTION 
     The present invention relates to a structure for providing a physical or visual barrier and a method for providing such a barrier, for example a fence or landscaping screen. 
     BACKGROUND TO THE INVENTION 
     There is often a need for barrier structures in both domestic and commercial environments. Barrier structures may be used to provide a visual barrier, for example for privacy, shade, or concealment, and/or a physical barrier, for instance to prevent access, or to provide shelter or containment. Being conspicuous by nature, the visual appearance of barrier structures is important. 
     Barrier structures typically include parts for assembly in situ, such as upright posts and cross-members or panels, which span between the posts. A widely used barrier structure is a fence comprising spaced apart concrete posts, each post having a vertical retaining groove on opposite sides. The posts are typically cemented in the ground. Prefabricated panels, typically of wood, are used to fill the space between the posts. Each panel is slid vertically into the grooves in two adjacent posts such that a panel spans between two posts. Such barrier structures may also comprise horizontal concrete beams, spanning between the lower ends of the posts, each bar having a horizontal retaining groove in which the lower edge of a panel can be seated. In this arrangement, the panels contribute little to the overall strength of the barrier structure. Instead, the structural integrity of the barrier is determined largely by the concrete posts, which are therefore vulnerable to damage, and may be inconvenient to replace. 
     The grooves in the posts and beam may collect rainwater, which can cause rotting of the edges of each wooden panel, requiring replacement of the entire panel. A further problem associated with these structures is that under high winds, the panels can deform and escape the retaining grooves. In addition, the concrete posts and beams are often considered unsightly. 
     It is an object of the present invention to provide a structure for providing a physical or visual barrier, and also a method of assembling such a structure, that addresses at least some of these problems. 
     SUMMARY OF THE INVENTION 
     According to a first aspect of the invention, there is provided a structure for providing a physical or visual barrier as set forth in Claim  1  of the appended set of claims. 
     The structure when in situ to provide the physical or visual barrier, comprises at least one post mounted to a supporting surface and to which is secured at least one slat by at least one wedge. The post comprises a beam that extends upwards from a footing. The beam comprises at least one longitudinally extending plate which at least partially encloses a hollow. The, or each, plate need not be planar but may be curved and in one embodiment there is just one plate that is curved into a cylindrical tube. 
     The beam may have at least one plate that extends between opposite left and right sides of the beam, and also may have at least one plate that extends between opposite front and rear sides of the beam. The beam is cut through by at least one slot that extends rearwards from the front side part of the way towards the rear side. The slot is configured to receive a portion of a slat when inserted into the slot in an insertion direction from the front side of the beam. The slat then extends laterally away from at least one of the sides. 
     Each slot has a width that provides a sufficient clearance gap with the slat whereby a tip of the wedge may be driven into the gap from one side of the beam to secure the slat to the beam. 
     In some embodiments of the invention, the elongate beam has a substantially square or rectangular envelope in a plane transverse to the longitudinal direction. 
     The post is preferably metallic. For example, the post may be formed from corrosion resistant steel. The slats are preferably non-metallic. For example, the slats may be planks, such as wooden planks, or lengths of plastic board. The material of the slats is most preferably more compliant in comparison with that of the post and wedges, so that the post and/or wedges can dig into the slats when the wedges are driven into place. The use of wedges to secure the slats allows the use of slats having different thicknesses. 
     The, or each, hollow allows air to circulate around edges of the slot and over a portion of the slat that intersects the hollow. This helps to prevent rot or corrosion of materials, for example metal of the beam and particularly the slat, when this is wooden. 
     The presence of the, or each hollow will also reduce the surface area of parts of the slot in contact with the slat (all other dimensions being equal). This has the effect of increasing the force in the engagement between these contact surfaces, which helps to secure the slat within the slot. 
     In a preferred embodiment of the invention, there are at least two wedges, and a first one of the wedges is driven into the clearance gap from one side of the beam and a second one of the wedges is driven into the clearance gap from an opposite side of the beam. 
     In one embodiment of the invention, the faces comprise at least one surface so shaped in the transverse plane perpendicular to the longitudinal direction as to encompass on three adjacent sides a hollow that extends longitudinally along the beam. Preferably, the hollow is a substantially U-shaped recess of the beam. In this case, the sides of the U are provided by the at least one plate extending between one pair of opposite sides of the beam and the base of the U is provided by the at least one plate extending between another pair of opposite sides of the beam. The beam may be provided by a U-section beam. The post may be manufactured from U-section mild steel. 
     In another embodiment of the invention, the faces comprise on each one of two opposite sides of the beam at least one surface so shaped in the transverse plane as to encompass on three adjacent sides a hollow that extends longitudinally along the beam. In this way, the beam is provided with a pair of hollows, the hollows extending along opposite sides of the beam. Preferably, each hollow is a substantially U-shaped recess of the beam. In this case, the beam may be provided by an I-section beam. 
     In one embodiment where the beam is provided with two opposing hollows, the slot intersects only one of the hollows. Alternatively, the slot may intersect both hollows. For example, where the beam is provided by an I-section beam (also called an I-beam), the slot may intersect the hollow provided on one side of the I-section. Alternatively, the slot may extend through a central wall of the I-section, thereby intersecting each of the opposing hollows. 
     Preferably, the at least one surface encompassing the or each U-shaped recess terminates in free edges at a side of the beam. 
     The advantage of a U-section beam, or an I-section beam, is that the open side or sides of the beam allow water to drain away, making it easier to avoid pooling of water and corrosion or deterioration of the post or slats when the structure is used outdoors. For this reason, it is helpful if parts of the at least one surface terminate along free edges along the sides of the post. Rain water may then flow out past these free edges. 
     When the beam is an I-beam or a U-beam, it is preferred if the plates are substantially flat. Corners or edges between plate are preferably radiused. Adjacent plates may be oriented at right angles to one another, as viewed in the lateral plane. 
     When the beam is an I-beam, the I-beam will have a first plate, a second plate and a third plate. The first and second plates are, respectively, opposite first and second flanges of the I-beam and the third plate is a web of the I-beam that extends between the flanges. The two hollows provided by the I-beam extending longitudinally along the beam on opposite sides of the web and between the flanges. 
     Preferably, the flanges each extend at right angles from longitudinally extending lateral edges of the web. 
     In one embodiment having the I-beam, the first face of the first plate provides the front side of the beam and the first face of the second plate provides the rear side of the beam. The first plate the third plate each have at least one aperture, a first one of the apertures in the first plate extending fully across the first plate between the opposite right and left sides of the beam to provide the opening to the slot and a second one of the apertures in the third plate extending from the first aperture towards the second plate to provide the slot. The slot opening is then in the externally directed face of one of the flanges. 
     In general, each of the first and second plates of the I-beam will have a pair of opposite side edges, these side edges extending between the first and second faces of the respective plate. In another embodiment employing the I-beam, a first one of these side edges of the first and second plates provides the front side of the beam, and a second one of these side edges of the first and second plates provides the rear side of the beam. The first plate and the second plate then each have at least aperture therein, a first one of these apertures in the first plate extending to the first side edge of the first plate and a second one of these apertures in the second plate extending to the first side edge of the second plate. The first and second apertures are aligned with each other in the lateral direction between the opposite right and left sides of the beam to provide the opening to the slot, and each of the apertures extends from the respective side edge towards the third plate to provide the slot. The slot opening is then in the two plate edges providing the front of the beam. 
     When the beam is a U-beam, the U-beam will have a first, second and third plates. The first and second plates are, respectively, opposite first and second flanges of the U-beam and the third plate is a web of the U-beam that extends between the flanges along one longitudinally extending edge thereof. The single hollow provided by the U-beam extends longitudinally along the beam on one side of the web and between the flanges. 
     Preferably, the first and second plates each extend at right angles from longitudinally extending lateral edges of the third plate. 
     In one embodiment employing the U-beam, each of the first and second plates has one side edge and each of these side edges extends between the first and second faces of the respective plate. The side edges of the first and second plates provide the front side of the beam, and a first face of the third plate provides the rear side of the beam. The first plate the second plate each have at least one aperture therein. A first one of these apertures in the first plate extends to the side edge of the first plate and a second one of these apertures in the second plate extends to the side edge of the second plate. The first and second apertures are aligned with each other in the lateral direction between the opposite right and left sides of the beam to provide the opening to the slot, and each of the apertures extends from the respective side edge towards the third plate to provide the slot. The slot opening is then in the two plate edges providing the front of the beam. 
     When the beam is a box-beam, the box-beam will have a first plate, a second plate, a third plate and a fourth plate. The first and fourth plates are opposite one another with a first face of the first and fourth plates providing, respectively the front and rear sides of the beam. The second and third plates are then opposite one another with a first face of the second and third plates providing, respectively the opposite right and left sides of the beam. The second faces of each of these four plates extends longitudinally along the beam to provide one hollow inside the box-beam. Preferably, each of the four plates extends at right angles from longitudinally extending lateral edges of adjacent plates. 
     In one embodiment employing the box-beam the first plate, the second plate and the third plate each have at least one aperture therein. A first one of these apertures in the first plate extends fully across the first plate between the opposite right and left sides of the beam to provide the opening to the slot and a second one and a third one of these apertures in, respectively, the second and third plates extends from the first aperture towards the fourth plate to provide the slot. The slot opening is then in the externally directed face of the first plate. 
     When the beam is a tube, the tube may have a single substantially cylindrical plate. The first face of the plate provides the front, rear, right and left sides of the beam. The second face of the plate extends longitudinally along the beam to provide a single hollow inside the tube. Preferably, the first and second faces of such a plate are concentric. 
     In one embodiment employing the tube the cylindrical plate has at least one aperture therein, the aperture extending across the single plate between the opposite right and left sides of the beam to provide the opening and the slot, 
     In all embodiments of the invention, it is preferred if there are a plurality of apertures spaced apart longitudinally along the length of the beam. Each of the spaces apart aperture provides a set of slots, each of which has an opening leading to a slot. 
     Each of the openings is preferably in the same side of the beam, so that the slats all have a similar orientation in the lateral direction. 
     In the embodiments in which the slot opening is in the two plate edges providing the front of the beam, the slot is, in effect, divided into two separate slot portions by a gap between the free plate edges. A first one of the slot portions may be cut through a plate extending between front and rear sides of the beam and extend rearwards from the free edge of the plate. Similarly, a second one of the slot portions may be cut through another plate extending between front and rear sides of the beam and extend rearwards from the free edge of the plate. In this way, the first and second slot portions are aligned with each other so that these function as a single slot for receiving the slat. 
     In other embodiments of the invention, the faces comprise at least one surface so shaped in the transverse plane as to fully encompass a hollow that extends longitudinally along the beam. In this case the hollow may be a hollow interior of the beam. Preferably, such a beam is provided by a box-section beam. 
     The advantage of a box-section beam is that the presence plates extending around a longitudinal axis of the beam adds strength against bending, thereby allowing the use of thinner material with lighter overall weight. 
     Preferably, at least part of the at least one plate spanning the front and rear sides of the beam is not cut through by the slot. The advantage of this is that the mechanical integrity of the beam is not compromised by the slots, and the slats can be oriented towards the front side of the beam, and preferably extending forwards of the front side of the beam, in order to provide a pleasing visual appearance which conceals or breaks up the view of the beam from the front side of the structure. 
     The slot may extend substantially perpendicular to the length of the beam, whereby the secured slat extends substantially horizontally in the lateral direction when the beam is oriented substantially vertically. 
     Preferably, the slot is tilted downwardly towards the front side of the beam, whereby a front edge of a secured slat is sloped downwardly relative to a rear edge of the secured slat when the beam is oriented substantially vertically. In this arrangement, the sloped surface of the slat helps to drain water away from the hollow of the beam. 
     The slot may be tilted downwardly towards the front of the beam and may be level in the lateral direction, whereby the front and rear edges of the secured slat are substantially level in the lateral direction. 
     Preferably, the slot does not fully span the hollow, whereby a rear edge of the secured slat is separated from a part of at least one plate defining a rear portion of the hollow by a gap within the hollow. This arrangement helps to prevent collection of water between the slat and a rear surface of the hollow and provides a space through which services, for example an electrical cable, can be routed. 
     In a preferred embodiment of the invention, the slot has a slat receiving portion that extends in the insertion direction from the front side of the beam towards the rear side of the beam. The slat receiving portion may have an extent less than a width of the slat when fully received in the slot. In this way, a free edge of the slat may extend forwards from a front side of the beam. This arrangement may help to drain water away from the beam, when the front edge of the slat is sloped downwardly relative to a rear edge of the slat. 
     Preferably, the slot has an upper side and a lower side when the beam is oriented substantially vertically. The wedge is laterally driven into the clearance gap between a lower side of the slat and the lower side of the slot. In this way, the slat helps to shield the wedge from rainfall, when the post is mounted outdoors, and may also help to visually hide the wedge from view. 
     In addition, the wedge will then lift the downwardly-facing surface of the slat above the upwardly facing surface of the slot, which helps to prevent moisture from collecting beneath the slat, thereby helping to reduce the effects of corrosion or rot over time. 
     Preferably, the upper side of the slot has at least one spike or tooth oriented towards the lower side of the slot, the, or each, tooth being engaged with the slat when the wedge is driven into the clearance gap. The tooth helps to secure the slat in the slot. Additionally, the tooth holds the slat at a distance from the upper side of the slot, thereby providing a water drainage gap between the upper side of the slot and an upper surface of the slat. 
     Preferably, the lower side of the slot is provided with at least one recess, the or each recess being sized to receive and guide a corresponding wedge as the wedge is laterally driven into the clearance gap. The recess facilitates insertion of the wedge into the clearance gap, and helps to prevent movement of the wedge in the insertion direction when the slat is secured in the slot. 
     In a preferred embodiment of the invention, the wedge has a taper leading to the tip of the wedge, the taper being provided by opposite first and second sides of the wedge. The first side of the wedge may have a substantially straight edge that is engaged with the slat. 
     In one embodiment, the straight edge has a ridge extending along its length, the ridge being engaged with the slat. The ridge guides insertion of the wedge and helps to prevent subsequent movement of the slat in the insertion direction. 
     In another embodiment of the invention, the second side of the wedge has an edge with a series of concave scallops. In this case, when the wedge is inserted into the clearance gap, part of the plate on one side of the slot engages with the concave surface of one scallop. In this way, the scallops help to prevent the wedge from working loose in the lateral direction. 
     The wedge will, in general, have opposite third and fourth sides, the third and fourth sides extending between the opposite first and second sides of the wedge. The wedge may then further comprise a base portion at a thick end of the taper, the base portion being provided with a bore therethrough between the third and fourth sides of the wedge. The bore may usefully provide a gripping feature to facilitate withdrawal of the tip of the wedge from the clearance gap. For example, the bore may provide purchase for a screwdriver, or a hooked pulling tool such as those commonly used to pull tent pegs from the ground. In this way, the wedge can be easily removed. 
     Preferably, the beam is of a metallic material. Preferably, the slat is a wooden plank. For example, the beam may be manufactured from steel or another metal, such that the at least one plate is of sufficient strength without being excessively thick and heavy. 
     According to a second aspect of the invention, there is provided a barrier installation as set forth in Claim  24  of the appended set of claims. 
     The supporting surface may be a granular base, and the footing may be a downwardly extending portion with at least one tapered tip driven into the granular base. A tapered tip such as a spike allows the barrier installation to be supported in the ground, for example in a garden or other outdoor space. The barrier installation may comprise a single post, with at least one slat extending from both the first and second sides of the beam. 
     The barrier installation may comprise at least three posts with the beams of the posts being in line with one another. At least two of the slats may be in line with one another sharing one of the slots in at least one of the posts, such that an end of one slat meets an end of another slat in the hollow interior of the beam. Each slat then extends only from one side of the beam. In this way, each slot can function to align two laterally adjacent slats, these slats extending laterally away from opposite sides of the beam, such that the size of the barrier installation is not limited by the length of the slats. Furthermore, the join between the slats can be concealed in the hollow interior of the beam. 
     The barrier installation may comprise at least one electrical fixture mounted to the post. The electrical fixture will, in general, be provided with electrical power by an electrical cable. Such an electrical cable may be routed to extend along the length of the post from the supporting surface to the electrical fixture through the hollow interior of the beam. This arrangement helps to conceal and protect the electrical cable. 
     The footing may comprise a mounting plate. The mounting plate may be provided with means for affixing the plate to a supporting base, for example clearance holes for bolts. 
     The mounting plate may extend transversely away from the post. For example, the plate may extend in a plane perpendicular to the length of the post. In this arrangement, the post can be mounted perpendicular to a solid surface, such as a concrete floor. 
     In another example, the plate may extend in a plane parallel with the length of the post. In this arrangement, the post can be mounted parallel to a solid surface, such as a wall. 
     According to a third aspect of the invention, there is provided a method of assembling a structure for providing a physical or visual barrier, as set forth in Claim  25  of the appended set of claims. 
     The use of wedges facilitates easy and non-destructive assembly and disassembly of the barrier structure. In this way, a method is provided by which the slats can be rearranged or replaced as often as required. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be further described, by way of example only, and with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a structure for providing a physical or visual barrier, according to a first preferred embodiment of the invention, having a post formed from a box-section beam with a hollow interior, a bottom end of which has a tapered tip for driving into the ground, and a plurality of transversely extending slats affixed in downwardly angled slots in a front side of the post; 
         FIG. 2  is a side view of part of the post of  FIG. 1 , showing how each slot has on a lower side at least one recess and on an upper side at least one backwardly-directed tooth, and how the slat is preferably inserted into the slot from the front side of the post; 
         FIG. 3  is a side view of the post after the slat has been inserted into the slot and a wedge has been inserted between a lower side of the slat and one of the recesses, in order to engage an upper side of the slat with the teeth; 
         FIG. 4  shows a first embodiment of the wedge of  FIG. 3 , the wedge having one side along which extends a ridge for engaging with the lower side of the slat, and an opposite side with a series of concave scallops; 
         FIG. 5  shows a second embodiment of the wedge of  FIG. 3 , the wedge having one side along which extends a ridge for engaging with the lower side of the slat; 
         FIG. 6  shows a third embodiment of the wedge of  FIG. 3 , the wedge having opposite tapering sides, each with a flat surface profile; 
         FIG. 7  is a perspective view from a rear side of the post of  FIG. 1 , showing how the wedge of  FIG. 6  is used to secure a slat within one of the slots, one of the scallops being engaged with opposite inner and outer surfaces of a side plate of the post; 
         FIG. 8  is a perspective view of a structure for providing a physical or visual barrier, according to a second preferred embodiment of the invention, similar to that of  FIG. 1  but having a post formed from a U-section beam, the arms of the U-section facing towards a front side of the post; 
         FIG. 9  shows a variation of the post of  FIG. 8 , having a lower mounting plate for bolting the post to a supporting surface, and at an upper end of the post a light fitting on a front plate; 
         FIG. 10  is a perspective view of a structure for providing a physical or visual barrier, according to a fourth preferred embodiment of the invention, similar to that of  FIG. 1  but having a post formed from a I-section beam, the arms of the I-section extending between a front side and a rear side of the post; 
         FIG. 11  is a perspective view of a structure for providing a physical or visual barrier, according to a fifth preferred embodiment of the invention, having a post formed from a I-section beam, the arms of the I-section extending between first and second sides of the post and the slot being cut through a central plate; 
         FIG. 12  is a side view of the post of  FIG. 11  after a slat has been inserted into each slot and wedges have been inserted between a lower side of the slat and a lower side of the slot, in order to engage an upper side of the slat with the teeth, the wedges being inserted from a side of the post and from a front side of the post; 
         FIG. 13  is a perspective view of a structure for providing a physical or visual barrier, according to a sixth preferred embodiment of the invention, having a post formed from a round hollow-section beam, the sides of the beam being curved around a hollow interior; 
         FIG. 14  shows how a series of the posts may be spanned by slats to provide a fence; and 
         FIGS. 15A to 15D  show four different designs of visual barriers, each having a single post and plurality of slats having a variety of lengths to provide visually pleasing outlines. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a first embodiment of a structure  1  for providing a physical or visual barrier. The structure comprises an elongate post  2  having an upper end  4  and a lower end  6 , and a plurality of slats  8 . As shown in  FIGS. 2 and 3 , each of the slats  8  is secured to the post  2  by at least one wedge  10 . The lower end  6  of the post comprises a footing  20 , which in this example is a lower end of the post terminating in a tapered tip  12 . In use, the tapered tip  12  is driven into the ground (not shown) up to a desired depth, indicated schematically by a dot-dashed line  14  on the post in  FIG. 1 . 
     The post  2  has a main body formed by an elongate box-section beam  16 , which is most preferably metallic, for example of galvanised steel or stainless steel, and which may optionally be powder coated to provide colour. The beam  16  has a hollow interior  18  of substantially square or rectangular section, that extends the full length of the beam  16  along a longitudinal direction between the footing  20  and the upper end  4  of the post  2 . 
     The beam  16  comprises a front plate  21  and opposite this a rear plate  22 , and extending between the front and rear plates, a left side plate  23  and opposite this a right side plate  24 . The hollow  18  is defined by internally oriented faces of each of the four plates  21  to  24 . The front, rear and side plates  21  to  24  define corresponding front, rear, left and right sides  31  to  34  of the beam  16 . In this example, the front, rear and side plates  21  to  24  of the beam are each extend along the length of the beam. In general, the beam needs to have at least one plate spanning opposite front and rear sides of the beam in a first transverse direction and at least one plate spanning opposite left and right sides in a second transverse direction. In this example, a single plate extends transversely around the beam, thereby spanning between front and rear sides  31 ,  32  and left and right sides  33 ,  34  of the beam. The plates extend transversely so that internal surfaces of the plates at least partially enclose a hollow. In this case, the internal surfaces of the plate completely enclose the hollow interior  18 , such that the beam is generally tubular, preferably having a generally square or rectangular cross section. 
     The beam  16  is provided along its length with at least one slot, here a series of slots  28 , each of which opens up towards the front side  31  of the beam  16 . Each slot  28  extends fully across the front plate  21 , preferably in a horizontal direction, and extends across the left and right side plates  23 ,  24  from the front plate  21  part way towards the rear plate  22 . Preferably, each slot  28  is angled downwards towards the front plate  21 . The front, rear and side plates of the beam preferably extend around the hollow interior  18 , as shown in  FIGS. 1 and 7 , except where cut through by the slots. 
     As shown in  FIGS. 1 to 3 , each slot  28  is arranged to receive at least one corresponding slat  8 . One slat  8  may extend continuously across the hollow interior  18  or two laterally adjacent slats  8 ′,  8 ″ may meet or abut one another within the hollow interior  18 . The slats are arranged to extend laterally away from the right and left side plates  23 ,  24 . In  FIG. 1 , the structure is shown with one of the slats removed to show the empty slot. 
     Although the slats  8  may be inserted into the slots  28  in a lateral direction from either the left or rights sides  33 ,  34 , it is more convenient if each slat is offered up from the front side  31  into an opening  30  of the slot in an insertion direction  27  from the front side  31  towards the rear side  32  of the beam  16 , as shown in  FIG. 2 . Once inserted, fully or substantially fully, as shown in  FIG. 3 , then the slat is secured in place by means of at least one wedge  10 . 
     The slats  8  in this embodiment are wooden planks, being elongate and having a width greater than their thickness. In other embodiments, the slats could be of plastic, especially recycled plastic, or metal, or other rigid material. 
     A main feature of the invention is the use of wedges  10  to secure the slats  8  in the slots  28 . Three embodiments of wedges  10 ,  10 ′ and  10 ″ are shown in  FIGS. 4 to 6 . Each wedge  10  is elongate and has a taper  15  defined by opposite first  41  and second  42  sides. The taper  15  ends in a tip  40  at one end of the wedge. Each wedge further comprises third  43  and fourth  44  sides extending along the length of the wedge between the first and second sides  41 ,  42 . The distance between the third and fourth sides  43 ,  44  defines a width of the wedge. To assist hammering or driving of the wedge into the clearance gap  29 , a head  11  is provided at the end of the wedge opposite the tip  40 , where the distance between the first and second sides  41 ,  42  of the wedge is greatest. The head  11  of the wedge meets the second side  42  of the wedge at a ledge  46  which is preferably a right angled ledge. A bore  48  extends through the head  11  between the third and fourth sides  43 ,  44  of the wedge  10 . In use, the first side  41  of the wedge is arranged to engage with a lower side  45  of a slat  8  and the second side  42  of the wedge is arranged to engage with the lower side  36  of a slot  28 . 
     In a one embodiment, shown in  FIG. 4 , the second side  42  of the wedge  10  is provided with a series of concave scallops  52 . The scallops  52  extend parallel to one another between the third and fourth sides  43 ,  44  of the wedge, perpendicular to the length of the wedge. Additionally, or alternatively, as shown in the embodiment  10 ′ in  FIG. 5 , the first side  41  of the wedge  10  comprises a ridge  50  extending along the length of the wedge. The ridge  50  is arranged to engage with the lower side  45  a slat  8 . Alternatively, the wedge may have substantially flat sides  41  to  44 , as in the embodiment  10 ″ shown in  FIG. 6 . 
     Referring again to  FIGS. 2 and 3 , each slot  28  has an upper side  35  and a lower side  36  where the slot passes through each side plate  23 ,  24 . The upper and lower sides  35 ,  36  are substantially parallel to one another. A width W of the slot  28  is defined by the minimum distance between substantially parallel opposed portions of the upper and lower sides  35 ,  36  of the slot  28  in each side plate  23 ,  24 . The width of the slot is sized to receive the thickness of one of the slats  8  with a clearance gap  29  between the lower sides  36  of the slot and the lower side  45  of the slat  8 , as can be seen in  FIG. 3 . 
     The upper sides  35  of each slot  28  are provided with at least one backwardly-directed tooth  38  which points towards the lower side  36  of the slot and away from the opening  30 . Each tooth  38  is arranged to engage with an upper side  47  of a slat  8  in use. Additionally, the or each tooth  38  holds the slat  8  at a distance from the upper side  35  of the slot, thereby providing a water drainage gap  37  between the upper side of the slot and the upper side  47  of the slat  8 . 
     As can be seen in  FIGS. 2 and 3 , each lower side  36  of each slot  28  is provided with a pair of recesses  54  extending into the side plates  23 ,  24  away from the upper side  35  of the slot. Each recess  54  has sides  55  and a base  56 , the distance between the sides  55  being sized to accommodate the width of a wedge  10 .  FIG. 3  shows wedges  10  in the recesses  54 , with a slat  8  received in each slot. 
     In use, one slat  8  (or optionally two laterally adjacent slats  8 ′,  8 ″, which meet within the hollow interior  18  of the beam  16 ) is inserted into each slot  28 . A portion of each slat is inserted in the insertion direction  27  into a slot, preferably from the front side  41  of the beam as shown in  FIG. 2 , such that the slat extends through the side plates  23 ,  24  away from the left and/or right sides  33 ,  34  of the beam. The slat therefore extends in at least one of two opposite second transverse directions  39 ,  39 ′ which are lateral directions with respect to the front side of the beam and the longitudinal direction of the beam, and which are also in this example substantially perpendicular to the insertion direction  27  along which each slat is preferably inserted into the slot. 
     To secure the slat  8  in the slot  28 , the tip  40  of a wedge  10  is inserted into the clearance gap  29  between the lower side  36  of the slot and the lower side  45  of the slat  8 , on each side of the beam. Each wedge is driven from the left or right side  33 ,  34  of the beam  2  towards the hollow interior  18 . As shown in  FIGS. 3 and 7 , each wedge is guided by one of the recesses  54 . Driving of the wedges presses the first side  41  of each wedge into engagement with the lower side  45  of the slat, which in turn presses the upper side  47  of the slat  8  into engagement with the or each tooth  38  on the upper side  35  of the slot. Each tooth digs in to the upper side  47  of the slat and helps secure the slat in the slot. The second side  42  of each wedge engages with the base  56  of the corresponding recess  54  in the lower side  36  of the slot. 
     Where the second side  42  of the wedge  10  has scalloped edges  52 , the base  56  of the recess  54  engages with one of the scallops, as shown in  FIG. 7 . In this way, the wedge may be secured to prevent movement of the wedge in one or the other of the second transverse directions  39 ,  39 ′. Movement of each wedge towards the hollow interior  18  of the beam  16  is limited either by the size of the clearance gap  29 , or by the ledge  46  which may abut the side plate  23 ,  24  at the base  56  of the recess  54 . 
     To remove the slats  8 , the wedges  10  may be pulled out of the gap  29  in one or the other of the second transverse directions  39 ,  39 ′, away from the hollow interior  18  of the beam  16 . To this end, the bore  48  in the head of each wedge may be engaged with a tool to aid removal of the wedge from the slot  28 . It should be noted that the use of wedges to secure the slats  8  allows the slots to accommodate slats having different thicknesses, by adjusting the extent to which the wedge is driven towards the hollow interior  18 . 
     In another embodiment (not shown), only one recess  54  may be provided in each lower side  36  of each slot  28 . In this case, the position of the recess in the left side plate  23  is offset from the position of the recess in the opposing right side plate  24 , such that when wedges are driven from opposing sides of the same slot  28  the tips  40  of the wedges do not collide in the hollow interior  18  of the beam  16 . 
     It should be noted that the positioning of the wedges  10  beneath the slats  8  helps to shield the wedges from rainfall, when the post  2  is mounted outdoors, and may also help to hide the wedges from view. 
     It should also be noted that the water drainage gap  37  allows water to drain between the upper side  35  of the slot  28  and the upper side  47  of the slat  8 , in embodiments with or without a front plate  21 . 
       FIGS. 8 and 9  show second and third embodiments  101 ,  201  of the invention in which features which are the same as in the first embodiment  1  are indicated with the same reference numerals. Features of the second and third embodiments which are similar to corresponding features of the first embodiment are indicated with reference numerals incremented by, respectively  100  and  200 . 
     In the second embodiment  101  the beam  116  does not have a front plate and so the beam presents an opening  49  that extends along the front side  31  of the beam  116  fully between the opposite upper and lower ends  104 ,  106  of the beam. The front side  31  of the beam  116 ,  216  is therefore defined by free edges  25 ,  26  of the side plates  23 ,  24  such that the beam has a U-shaped cross section, as shown in  FIG. 8 . 
     The post  202  of the third embodiment  201  is similar to that  102  the second embodiment  101  except that the beam  216  has a reinforcing strap  66  at the upper end  204  of the beam  216 . The front side  31  of the beam  216  present an opening  149  between the reinforcing plate and the lower end  206  of the beam  216 . 
     In both the second and third embodiments  101 ,  102 , the beam  116 ,  216  comprises a rear plate  22 , and extending forwards of the rear plate, a left side plate  23  and opposite this a right side plate  24 . In each case, the hollow  18  is therefore defined by internally oriented faces of each of the three plates  22  to  24 , which therefore partially enclose the hollow. 
     Because there is no front plate in the second and third embodiments  101 ,  201 , each slot  128  is divided into separate slot portions  128 ′,  128 ″,  228 ′,  228 ″ by a gap between the free edges  25 ,  26 ,  125 ,  126  of the side plates. One of the slot portions  128 ′,  228 ′ is cut through the left side plate  23  and extends rearwards from the free edge  25 ,  125  of the left side plate. Similarly, a corresponding slot portion  128 ″,  228 ″ is cut through the right side plate  24  and extends rearwards from the free edge  26 ,  126  of the right side plate. In this way, the two slot portions  128 ′,  128 ″,  228 ′,  228 ″ are aligned with each other so that these function as a single slot  128 ,  228  for receiving a slat  8 , as can be seen in  FIGS. 8 and 9 . In this case, where there is only one plate extending between left and right sides  33 ,  34  of the beam, the beam  116 ,  216  may be provided by a U-section beam. 
     The post  102  of the second embodiment  101  has a footing  120  with a tapered tip  112  which has the same taper as the first embodiment 1. 
     In the third embodiment  201 , the footing  220  comprises a mounting plate  60  extending transversely away from the lower end  206  of the post  202 . In one example, shown in  FIG. 9 , the mounting plate  60  is a substantially rectangular plate extending in a plane perpendicular to the length of the post  202 . Mounting holes (not shown) are provided adjacent to each corner  57  of the mounting plate  60 , such that the mounting plate can be secured to a solid surface by fasteners. In the example of  FIG. 9 , the fasteners are bolts, the heads  62  only of which are shown in  FIG. 9 . Although not shown, the bolts are conventional steel bolts each having a shaft that extends through a corresponding hole in the mounting plate  60  to engage with a threaded sleeve which may, for example, be set in a concrete base. In other examples, screws, pins, pegs or other suitable fasteners could be used. In another alternative (not shown), a mounting plate may extend in a plane parallel to the length of the post  202 , such that the barrier structure  201  can be secured to a vertical supporting surface, such as a wall. 
     In the embodiments of  FIGS. 1 and 8 , the footing  20 ,  120  includes the downwardly pointing tapered tip  12  comprising a part of the rear plate  22  and the side plates  23 ,  24 . The rear plate  22  extends further towards the lower end  6 ,  106  of the post  2 ,  102  than the front plate  21 . In these cases, the side plates  23 ,  24  are tapered at the lower end  6 ,  106  of the post  2 ,  102  such that a lower edge  82  of each side plate  23 ,  24  extends downwardly and towards to a bottom edge  81  of the rear plate  22 . 
       FIGS. 10 to 13  show fourth, fifth and sixth embodiments  301 ,  401 ,  501  of the invention in which features which are the same as in the first embodiment  1  are indicated with the same reference numerals. Features of these embodiments which are similar to corresponding features of the first embodiment are indicated with reference numerals incremented by, respectively  300 ,  400  and  500 . 
     In the fourth embodiment  301  of the invention, the beam  316  has only one plate extending between left and right sides  33 ,  34  of the beam, which in this case comprises a middle or central plate  17 . As shown in  FIG. 10 , the central plate  17  extends between left and right side plates  323 ,  324  of the beam, part way between the front and rear sides  31 ,  32  of the beam. In this way, the front and rear sides  31 ,  32  of the beam  316  are defined by free edges of the side plates  323 ,  324 . The front side  31  of the beam is defined by front edges  325 ,  326  of the side plates  323 ,  324  and the rear side of the beam is defined by free edges  325 ′,  326 ′. A pair of hollows  318 ′,  318 ″ is thereby provided between the side plates  323 ,  324 , with one hollow on either side of the central plate  17 . Each of the hollows  318 ′,  318 ″ is defined by internally oriented faces of each of the three plates  17 ,  323 ,  324 , which therefore partially enclose the hollow. 
     As in the second and third embodiments  101 ,  201 , there is an opening  249  between front edges  325 ,  326  of the side plates  323 ,  324  which in this case leads to a front one  318 ′ of the hollows. 
     The beam  316  is provided with slots  328  opening at the front side  31  of the beam. Since there is no front plate, each slot  328  is divided into slot portions  328 ′,  328 ″ by a gap between the free edges  325 ,  326  of the side plates. One of the slot portions  328 ′ is cut through the left side plate  323  and extends rearwards from the free edge  325  of the left side plate. Similarly, a corresponding slot portion  328 ″ is cut through the right side plate  324  and extends rearwards from the free edge  326  of the right side plate. In this way, the two slot portions  328 ′,  328 ″ are aligned with each other so that these function as a single slot  328  for receiving a slat  8 , as can be seen in  FIG. 10 . In this case, having a central plate  17  instead of front and rear plates, the beam  316  may be provided by an I-section beam. 
     In this fourth embodiment, the footing  320 , comprises a tapered tip  312 . As shown in  FIG. 10 , the central plate  17  extends further towards the lower end  306  of the post  302  than the side plates  323 ,  324 . The side plates  323 ,  324  are tapered at the lower end  306  of the post  302  such that a lower edge  82  of each side plate  323 ,  324  extends downwardly and towards to a bottom edge  381  of the central plate  17 . 
     Although not shown, in the second, third and fourth embodiments  101 ,  201 ,  301 , the slats  8 ,  8 ′,  8 ″ are secured using the same wedges  10  and technique as described above in relation to the first embodiment  1 . The slots  128 ,  228 ,  328  may also have any of the same arrangements of teeth  38  and recesses  54  as described above. 
     In the fifth embodiment  401  of the invention, shown in  FIG. 11 , the beam  416  does not have side plates, instead having a middle or central plate  117 . The central plate  117  extends between front and rear plates  421 ,  422 , part way between the left and right sides  33 ,  34  of the beam  416 . In this way, the front and rear sides  31 ,  32  of the beam are defined by the front and rear plates  421 ,  422 . The left and right sides  33 ,  34  of the beam are defined by free edges of the front and rear plates  421 ,  422 . The left side  33  of the beam is defined by left edges  71 ,  72  of the front and rear plates  421 ,  422 . and the right side of the beam is defined by right edges  71 ′,  72 ′ of the front and rear plates  421 ,  422 . A pair of hollows  418 ′,  418 ″ is thereby provided between the front and rear plates  421 ,  422 , with one hollow on either side of the central plate  117 . Each of the hollows  418 ′,  418 ″ is defined by internally oriented faces of each of the three plates  117 ,  421 ,  422 . 
     The beam  416  is provided with slots  428  opening at the front side  31  of the beam  416 .  FIG. 11  shows the structure with one of the slats  8  removed to show the empty slot  428 . Each slot is cut through the front plate  421  and through the central plate  117 . Each slot extends upwardly and towards the rear side  32  of the beam. In this way, each slot intersects both hollows  418 ,  418 ″. 
       FIG. 12  shows a side view of the beam  416 , showing a slat  8  secured in each slot  428 . In a similar manner to the first embodiment  1 , the lower side  436  of each slot is provided with a recess  54  for guiding a wedge  10  and the upper side  435  of each slot is provided with teeth  38  for engaging with the upper surface  47  of a slat  8 . 
     Additionally, in this fifth embodiment  401 , the slot  428  is arranged to receive wedges  10  in the insertion direction  27 , where the slot cuts through the front plate  421 . An opening  430  of the slot  428  is defined where the slot is cut through the front plate  421 . A lower side  73  of the opening is provided with two recesses  154  cut into the front plate  421 , as shown in  FIG. 11 . The recesses  154  are spaced apart on the lower side  73  of the opening, such that the central plate meets the front plate between the recesses. Each recess  154  in front plate  421  is shaped to accommodate the width of a wedge  10 . 
     To secure a slat  8  in a slot  428 , a wedge is driven into the clearance gap  29  in one of the second transverse directions, guided by the recess  54  in the central plate  117 , in a similar manner to the first embodiment  1 . Additionally, wedges  10  are driven through a clearance gap  129  between the lower side  45  of a slat and the lower side  73  of the opening  430 . Each additional wedge  10  is driven in the insertion direction  27  from the front side  31  of the beam  416  and is guided by one of the recesses  154 . In  FIG. 12 , a wedge  10  can be seen extending towards the rear side of the beam  416 . The tip  40  of the wedge extends towards the rear plate  422 , underneath the slat  8 . 
     In this fifth embodiment, the footing  420  comprises a tapered tip  412 . As shown in  FIG. 11 , the central plate  117  extends further towards the lower end  406  of the post  402  than the front and rear plates  421 ,  422 . The front and rear plates  421 ,  422  are tapered at the lower end  406  of the post  402  such that lower edges  482  of the front and rear plates  421 ,  422  extend downwardly and taper towards to a bottom edge  481  of the central plate  117 . 
       FIG. 13  shows a sixth embodiment  501  of the invention, in which there is a single plate  521  that is curved to extend continuously around all four sides  31  to  34  of the beam  516 . The plate  521  is continuous and curved around a hollow interior  518  such that the beam is generally cylindrical. In this embodiment, the beam  516  has a generally circular cross-section and may be provided by a round hollow-section beam. The hollow  518  is defined by a single continuous internally oriented face of the plate  521 . 
     The beam is provided with slots  528  opening at the front side  31  of the beam. Although not shown, in this embodiment, the slats  8  are secured using the same wedges  10  and technique as described above in relation to the first embodiment. The slots  528  may also have any of the same arrangements of teeth  38  and recesses  54  as described above. 
     In this sixth embodiment, the footing  520  comprises a tapered tip  512 . As shown in  FIG. 13 , the rear side  32  of the plate  521  extends further towards the lower end  506  of the post  502  than the left and right sides  33 ,  34  of the plate  521 . The left and right sides of the plate  521  are tapered towards the lower end  506  of the post  502  such that a lower edge  582  of the plate  521  extends downwardly and towards to a bottom edge  581  of the plate  521 . 
       FIG. 14  shows how the post  2  and slats  8  of the first embodiment  1  may be used to construct a barrier installation  80 , having at least two posts spanned by slats. Here, the barrier installation is a fence  90  that extends over the ground  92 . Each slat  8  is received in a slot  28  or slot portion  28 ′,  28 ″ in at least two posts  2 . For example, as shown in  FIG. 14 , laterally adjacent slats  8 ′,  8 ″ in line with one another can share a common slot  28 , such that an end of one slat  8 ′ meets an end of another slat  8 ″ in the hollow interior  18  of the beam  16 . Each slat  8 ′,  8 ″ then extends only through a slot portion  28 ,  28 ″ in one of the side plates  23 ,  24 . In this way, each slot  28  can function to join two slats  8 ′,  8 ″ together, such that the size of the barrier installation  80  can be extended to provide a fence and is not limited by the length of the slats  8 . The join between the slats  8 ′,  8 ″ may also be concealed in the hollow interior  18 . Although not shown, the posts of any of the above-described embodiments may similarly be used to construct a barrier installation. 
     In embodiments where the footing comprises a tapered tip, the tapered tip is arranged to be driven into a granular base such as the ground, in order to support the post in an upright position, thereby providing a barrier installation. For example, referring to  FIGS. 1, 8, 10, 11 and 15A to 15D , the tapered tip  12 ,  112 ,  312 ,  412  for the footing  20 ,  120 ,  320 ,  420  is arranged to be driven into a granular base such as the ground  92  in order to support the post  2 ,  102 ,  302 ,  402  in an upright position. In use, the tapered tip would be driven into the granular base sufficiently far to ensure a stable orientation of the post, for example up to a level as indicated by the dot-dashed lines  14 ,  114 ,  314 ,  414 . The granular base may be soil, sand, gravel or other non-consolidated particulate matter. Although not shown, the footing could, alternatively, be set in concrete. 
     In all embodiments of the invention, the post may provide support for additional features, e.g. electrical fixtures. For example, in the embodiment of  FIG. 9 , a light fitting  64  is, optionally, provided on the reinforcing strap  66  at the upper end  204  of the post  202 . The hollow  18  of the beam  216  provides a space through which a cable  68  for an electrical fixture can be routed. In this way, the cable  68  may be concealed and protected. The cable may be routed through a hole  70  where one of the side plates  23 ,  24  meets the mounting plate  60 . 
     The use of wedges  10  allows the slats  8  to be removed and repositioned as desired. The slats  8  may therefore be arranged into a variety of designs, examples of which are shown in  FIGS. 15A to 15D . In addition, the slats need not all be of the same length, but can be varied to change the shape of the outline provided by the barrier structure  1 . In this way, visually pleasing designs may be created. 
     The invention therefore provides a convenient and versatile structure for providing a physical or visual barrier, and also a method of assembling such a structure, which may be used as part of a barrier installation or as a visually pleasing feature, for example in ornamental gardens.