Collapsible barrier unit Field of the Invention

[0001] The present invention relates to a collapsible barrier unit. Background to the Invention

[0002] It is known to provide both permanent and temporary barriers. Irrespective of the amount of time that a barrier is used for, it is desirable to make transport erection and storage of barriers as efficient as possible

[0003] It is known to provide a barrier unit for various purposes mainly managing flow, for example including for animals, traffic, and crowd barrier units. For example a crowd barrier unit of the type often deployed on streets, is a substantially rectangular frame with rounded upper corners and a series of bars running in parallel from a top member of the frame to a bottom member of the frame.

[0004] Often times a barrier unit is provided with feet to allow it to stand by itself. Such barrier units can be connected together to provide a chain or series of linked barriers which then act as a continuous barrier/fence to prevent or restrict access to a given area. The barrier units are rigid and while simple in construction and do not require erection they must be transported and stored. The volume occupied by each barrier unit is substantially greater than the volume occupied by its component parts leading to transport and storage inefficiencies as a large volume will be unoccupied. Furthermore, it is likely that substantial empty space will be present in any storage or transport configuration, because it may not be possible to arrange the barrier units to occupy substantially all of the space simply because their shape and rigidity does not allow them to occupy a given space in a space efficient manner.

[0005] UK patent publication GB 2475898 describes a collapsible barrier unit with a base member that is for securing to a surface. Parts of the barrier unit are detachable to allow the barrier unit to be collapsed. In particular, part of a handrail, and an upright must be removed from the barrier unit to allow collapsing.

[0006] UK patent publication GB 2349900 describes a collapsible barrier which collapses in a parallelogram fashion into a ground box. Cover plates are used to maintain the barrier in an erect configuration.

[0007] Other collapsible barriers are known for example those driven by motors and used at large scale. Summary of the Invention

[0008] In one aspect, the present invention provides a collapsible barrier unit comprising:

(i) a top rail having a left side and a right side;

(ii) a left hand foldable barrier section;

(iii) a right hand foldable barrier section;

wherein the left hand foldable barrier section hangs from the top rail and folds up and towards the right side of the top rail; and

wherein the right hand foldable barrier section hangs from the top rail and folds up and towards the left side of the top rail.

[0009] This provides a very compact configuration. The barrier unit of the present invention occupies, in its collapsed configuration, substantially less volume than a comparable non-collapsible barrier unit.

[0010] The top rail can also act as a handrail.

[0011] In relation to the present invention the expression collapsible barrier unit refers to a unitary and/or integral barrier unit that is connectable to other barrier units of the same type to form a continuous barrier. In this respect the unit is modular and it together with other units forms a barrier. It will be appreciated then that a collapsible barrier unit relates to a construction of a single unit, and not to a construction formed by two or more units. So, for example, when a collapsible barrier unit is said to refer to a left hand foldable barrier section and a right hand foldable barrier section, these sections are within a single collapsible barrier unit. A construction formed by two or more units will be referred to as a barrier or fence.

[0012] While collapsible barrier units of the present invention could additionally be secured to a structure, they are self-supporting units, i.e. they can be erected and can stand up by themselves.

[0013] Desirably the top rail forms a channel extending from the left side to the right side. Suitably the left hand foldable barrier section hangs within the channel from the top rail and folds up and into the channel on the right side of the top rail. It is desirable that the right hand foldable barrier section hangs within the channel from the top rail and folds up and into the channel on the left side of the top rail. This is a very simple arrangement that allows for efficiency in storage.

[0014] Desirably in a folded configuration the left hand foldable barrier section and the right hand foldable barrier section are hidden within the channel. This means that the overall profile of the device in its collapsed or storage configuration is no greater than the profile of the top rail itself. [0015] All components fold up into the top/hand rail so the barrier unit can be transported and stored in a more compact format.

[0016] The top rail consists of a front and rear section. The rear section will have the barrier components connected to the left and fold up to the right. The front section will have the barrier components connected to the right and fold up to the left. The top rail will join these two components to itself to form a single assembly or barrier unit. This will create a top rail that can function as a hand rail that has components that will fold by each other when being stored. This layout of this design can be mirrored both left to right or front to back.

[0017] The top rail may have a front and rear section, and one of the left hand foldable barrier section or the right hand foldable barrier section, may fold up and into the front section, and the other foldable barrier section may fold up and into the rear section. This means that the barrier sections can be folded to a position where they lie alongside each other. They are easily deployed from this position, for example under gravity.

[0018] The top rail not only acts as containment unit but also as, or functions to provide, one or more of a handrail; part of a locking mechanism to maintain rigidity of the barrier unit when erect; holds pivotal geometry that allows control of all components as it opens and closes; internal surfaces acts as stops to prevent connecting parts from passing beyond 90 degrees; a main beam that resists loads placed from above;

supports all vertical loads placed on it through the rods which support the base;

recessed connections from the top surface of the top rail to maintain a flat surface on the top.

[0019] It is desirable that the left hand foldable barrier section and the right hand foldable barrier section unfold under gravity towards an erect configuration of the barrier. For example they may be releasable by a single mechanism or by individual mechanisms. Folding under gravity allows for easy erection of the barrier unit once positioned where it is desired to use it. It is desirable that the barrier sections unfold in a pendulum type action towards an erect configuration where the equilibrium position of the pendulum type action is an erect configuration of the device. With the equilibrium position being the desired position for erection, this again allows for ease of handling and erection. Desirably a retaining mechanism is provided to retain the barrier sections in the erect configuration.

[0020] Suitably the left hand foldable barrier section and the right hand foldable barrier section each comprise at least two rods that are pivotally connected to the top rail. This allows for a parallelogram type arrangement which in turn allows for ease of collapsing. [0021] For example the left hand foldable barrier section may further comprise a left hand bottom rail and within the left hand foldable barrier section at least two spaced apart rods are each independently pivotally connected to the top rail by respective top pivots and to the left hand bottom rail by respective bottom pivots.

[0022] Similarly the right hand foldable barrier section may further comprise a right hand bottom rail and within the right hand foldable barrier section at least two spaced apart rods are each independently pivotally connected to the top rail by respective top pivots and to the right hand bottom rail by respective bottom pivots. Again this is a simple arrangement for both erection and collapsing of the barrier units of the invention. For example erection and collapsing may both be achieved by a simple pivoting action.

[0023] The at least two spaced apart rods in the left hand foldable barrier section may fold into the configuration of a flat parallelogram shape with the rods overlapping with, and abutting, each other. The at least two spaced apart rods in the right hand foldable barrier section may fold into the configuration of a flat parallelogram shape with the rods overlapping the rods overlapping with, and abutting, each other. This provides a very compact configuration when the rods are as close as possible together thus minimising the space they occupy and reducing the overall profile.

[0024] Desirably each rod has an open hook shape defining an open mouth at a top end thereof for pivotally connecting to a top pivot; and an open hook shape defining an open mouth at a bottom end thereof for pivotally connecting to a bottom pivot, and the respective open mouths of the open hook shapes of each rod face in opposite directions relative to the direction of folding. For example one will face in a clockwise direction and the other will face in an anticlockwise direction.

[0025] The open mouth of the open hook shape at a top end of a rod may face away from the direction of folding; and the open mouth of the open hook shape at a bottom end of a rod may face towards the direction of folding.

[0026] It is desirable that each rod snap fits to at least one of a top pivot and a bottom pivot and desirably both.

[0027] Suitably a barrier unit of the invention comprises two support legs on which it can stand in an erect configuration and wherein:

a left hand leg is provided on the left hand foldable barrier section;

a right hand leg is provided on the right hand foldable barrier section;

and wherein the left hand leg hangs from the top rail and folds up and towards the right side of the top rail; and wherein the right hand leg hangs from the top rail and folds up and towards the left side of the top rail.

[0028] To reinforce the erect or standing configuration of the barrier unit of the invention a left hand strut may be provided which acts, in an erect configuration of the collapsible barrier unit, to brace the left hand leg against the left side of the top rail.

[0029] A right hand strut may be provided which acts, in an erect configuration of the collapsible barrier unit, to brace the right hand leg against the right side of the top rail.

[0030] Desirably the left hand leg and the right hand leg each have a folding mechanism that allows that leg to move, between a compact configuration for storing to a standing configuration for supporting the collapsible barrier unit, the standing configuration having an increased footprint for greater standing stability.

[0031] Suitably the left hand leg and the right hand leg each have a folding mechanism that includes leg portions that move by splaying apart, so that each leg can move from a compact configuration for folding with the leg portions in a non-splayed position to a standing configuration for supporting the collapsible barrier unit, where the leg portions are in a splayed position for greater standing stability. By splaying apart the stability of the barrier unit of the invention is increased. Furthermore this is a simple construction where the weight of the barrier unit holds the legs in the splayed position.

[0032] The left hand leg and the right hand leg may each have a folding mechanism that includes three leg portions that can move from a compact configuration where the leg portions fold substantially flat against each other to a triangulated standing position that provides greater standing stability.

[0033] The three leg portions may be an upright leg portion, a supporting leg portion and a bracing leg portion, wherein, in the triangulated standing position:

the upright leg portion and the supporting leg portion splay apart to form the sides and apex of a triangle;

the bracing leg portion forms the base of the triangle with one end of the bracing leg portion attached to the supporting leg portion and the other end for sitting on the ground; and

the upright leg portion sits on the bracing leg portion at a position between the two ends of the bracing leg portion.

[0034] A collapsible barrier unit according to the invention may comprise a tip-over prevention mechanism for counteracting tip-over forces the tip-over prevention mechanism comprising a free hanging counterbalance, that is substantially aligned with the collapsible barrier unit when the collapsible barrier unit is upright in an erect configuration but which can pivot outwardly with respect to the collapsible barrier unit when the collapsible barrier unit experiences tip-over forces.

[0035] The tip-over prevention mechanism may take the form of a centre recovery leg. The tip-over prevention mechanism has a number of functions. It will act as a backup support for barrier units that get overloaded with weight on the centre section of the handrail. It will pivot out in the event of a "tip over" due to either wind or other similar force. Its length will be short enough that it will not interfere with un-level ground but long enough to prevent an unrecoverable topple.

[0036] A retaining mechanism may be provided for holding the left hand foldable barrier section and the right hand foldable barrier section in a folded configuration. Upon release from a folded configuration by the retaining mechanism, the left hand foldable barrier section and the right hand foldable barrier section unfold under gravity towards an erect configuration of the barrier unit.

[0037] The top rail has a first and second end and each end may have a coupling for coupling a first collapsible barrier unit of the invention to a second collapsible barrier unit of the invention. The coupling may be a male part and a female part and one of a male part or a female part is provided on each of the first and second end, desirably wherein a male part is on a first end and a female part is on the second end. This allows for ease of meeting the barrier units together to form a continuous barrier unit. Mating is achieved by inserting the male part into the female part. It may be held there by the weight of the barrier unit or clipped together through the use of geometry between the two parts. The coupling may allow a first collapsible barrier unit of the invention to be attached to a second collapsible barrier unit of the invention in a nonlinear manner, for example at an angle.

[0038] Suitably the coupling allows a first collapsible barrier unit of the invention to be pivotally attached to a second collapsible barrier unit of the invention so that the angle at which the barrier units can be arranged with respect to each other in an erect configuration can be varied while they are coupled together.

[0039] Another option is to use cables or a net or some similar flexible obstruction as part of the barrier unit. For example a net could be used to prevent people from placing their feet onto parts of the barrier unit and thus preventing the placing of unnecessary loads on the structure.

[0040] It is desirable that parts that fold into contact with others have an open cross sectional shape such as U or H profile to allow components to be stored within the cavity of these shapes when the barrier unit is folded. These shapes are structurally strong shapes for holding loads but also ideal to allow storage when flat packed. [0041] It will be appreciated that the leg(s) may be provided with an arrangement to allow them to be secured to underlying ground. For example a leg or a foot thereof may have a hole defined therein to allow pegs or pins to be driven through. This will hold the barrier unit in position during high winds when on soft ground.

Brief Description of the Drawings

[0042] Embodiments of the invention will be described, by way of example only, with reference to the accompanying drawings in which:

[0043] Figure 1 is a front view of a collapsible barrier unit of the invention in a collapsed or storage configuration;

[0044] Figure 2 is a front view of the collapsible barrier unit of Figure 1 moving (under gravity) from the storage configuration toward an erect or standing configuration;

[0045] Figure 3 is a front perspective view of the collapsible barrier unit of Figure 1 in an erect or standing configuration;

[0046] Figures 4 to 9 show various stages in the collapse of the barrier unit from the erect or standing configuration of Figure 3 back to the collapsed or storage

configuration of Figure 1 ;

[0047] Figure 10 shows a front view of a series of (three) collapsible barrier units of the invention linked together to form a continuous barrier;

[0048] Figures 11 A to C is a schematic diagram showing the erection or

folding/collapsing action of a support leg of a barrier unit of the invention;

[0049] Figure 12 is a schematic diagram showing a mechanism for folding/collapsing or erection action of a foldable barrier section of a barrier unit of the invention in the erect or standing configuration;

[0050] Figure 13 is a schematic diagram showing a mechanism for folding/collapsing or erection action of a foldable barrier section of a barrier unit of the invention in the folded or collapsed configuration;

[0051] Figure 14 A shows a plan view of the arrangement of parts of a barrier unit relative to the hand rail in the erected position; while Figure 14B shows a sectional view thereof in the folded position; and

[0052] Figures 15 A to C is a schematic diagram showing the operation of a tip-over prevention mechanism for counteracting tip-over forces the tip-over prevention mechanism comprising a free hanging counterbalance.

[0053] It will be appreciated that the drawings are schematic in nature and are not all to the same scale. Detailed Description of the Drawings

[0054] The present invention will now be described with reference to Figures 1 to 15. The invention relates to collapsible barrier unit 1 comprising a top rail 5 having a left side 6 and a right side 7. It has a left hand foldable barrier section 8, and a right hand foldable barrier section 9.

[0055] The left hand foldable barrier section 8 hangs from the top rail 5 and folds up and towards the right side 7 of the top rail 5. The right hand foldable barrier section 9 hangs from the top rail 5 and folds up and towards the left side 6 of the top rail 5.

[0056] Figures 4 to 9 show various stages in the folding or collapse of the collapsible barrier unit 1 from the erect or standing configuration of Figure 3 towards the stowed configuration of Figure 1. It will be appreciated that the reverse of that sequence i.e. the sequence from Figure 9 to Figure 3 show various stages in the erection of the collapsible barrier unit 1. The figures show the independent folding up of the left hand foldable barrier section 8 and the right hand foldable barrier section 9.

[0057] Figure 2 is a front view of the collapsible barrier unit 1 of Figure 1 moving under gravity from the storage configuration toward the erect or standing configuration of Figure 3. It will be appreciated that if the top rail is held with foldable barrier sections 8,9 facing downwards, then the foldable barrier sections 8,9 will move under gravity towards the erect configuration of Figure 3.

[0058] A mechanism can be utilised to lock it in the storage position of Figure 1 and the same or a different mechanism can be utilised to lock it in the standing

configuration of Figure 3.

[0059] The top rail 5 has a front wall 10, a rear wall 1 1 , and a bridging wall 12 which runs between the front wall 10 and the rear wall 1 1 . The top rail 5 is thus in the form of a channel section with a channel 15 extending from the left side 6 to the right side 7. The front and rear walls 10,1 1 define the sides of the channel 15 and the bridging wall

12 defines the base of the channel 15. It will be appreciated that in the orientation for erection of the barrier unit 1 as shown in all of the figures, the channel 15 faces downwardly.

[0060] The left hand foldable barrier section 8 hangs within the channel 15 from the top rail 5 and folds up and into the channel 15 on the right side 7 of the top rail 5. A top end

13 of the left hand foldable barrier section 8 is hingedly connected to the top rail 5. It remains connected to the top rail 5 as will be described in more detail below.

[0061] The right hand foldable barrier section 9 hangs within the channel 15 from the top rail 5 and folds up and into the channel on the left side 6 of the top rail 5. A top end 16 of the right hand foldable barrier section 7 is hingedly connected to the top rail 5. It remains connected to the top rail 5 as will be described in more detail below.

[0062] It will be appreciated that the top rail 5 can acts as a handrail, for example for pedestrians passing a barrier unit 1 or a series of barrier units 1 .

[0063] As can be clearly seen from Figure 1 , in a folded configuration, the left hand foldable barrier section 8 and the right hand foldable barrier section 9 are hidden within the channel 15. The overall profile of the barrier unit 1 in the collapsed configuration is thus that of the top rail 5.

[0064] It will be appreciated that the left hand foldable section 8, and the right hand foldable section 9 fold alongside each other in an overlapping arrangement.

[0065] As is desirable in all embodiments the top rail 5 is wide enough to

accommodate this folding and has within channel 15 a front section proximate the front wall 10 and a rear section proximate the rear wall 1 1.

[0066] As best seen from Figure 3 to 9 the left hand foldable section 8 is to the front 2 of the barrier unit 1 . The right hand foldable section 9 is to the rear 3 of the barrier unit 1 . It will be appreciated that this can be easily reversed, either by turning the barrier unit through 180 degrees so that the barrier sections are swapped from left to right and vice versa or by changing the construction.

[0067] The left hand foldable barrier section 8 passes in front of right hand foldable barrier section 9 and folds up and into the front section. The right hand foldable barrier section 9 passes behind left hand foldable barrier section 8 and folds up and into the rear section.

[0068] The left hand foldable barrier section 8 and the right hand foldable barrier section 9 unfold under gravity towards an erect configuration of the barrier unit. In

Figure 2 both the left hand foldable barrier section 8 and the right hand foldable barrier 9 section have been released (from their position in Figure 1 within the top rail 5) at the same time to fall under gravity and are shown having moved towards the standing or erect position. A simple retaining mechanism with a release can be used to release both together or one at a time.

[0069] The left hand foldable barrier section 8 and the right hand foldable barrier section 9 each swing to unfold in a pendulum type action towards an erect

configuration. The weight of each section when released is enough to cause it to swing in this way. The equilibrium position of the pendulum type action is an erect configuration of the device. This position is shown in Figure 3.

[0070] The left hand foldable barrier section 8 comprises a series of spaced apart rods 20 that are pivotally connected to the top rail 5. The pivotal connection is best seen in Figure 12. In Figure 12 the top rail 5 is represented schematically. The left hand foldable barrier section 8 comprises a left hand bottom rail 25. In Figure 12 the top rail 5 and the left hand bottom rail 25 are represented schematically.

[0071] The rods 20 are each independently pivotally connected to the top rail 5 by respective top pivots 21. The rods 20 are independently pivotally connected to the left hand bottom rail 25 by respective bottom pivots 22.

[0072] The spaced apart rods 20 in the left hand foldable barrier section 8 (in the direction of Arrow A in Figure 12) fold into the configuration of a flat parallelogram shape (the shape in Figure 13) with the rods 20 (partially) overlapping lengthwise, and abutting, each other. In particular the bottom end 24 of a first rod 20 folds alongside and abuts the top end 23 of a neighbouring rod 20. It will be appreciated that during erection of the barrier unit 1 , the rods 20 move from the position shown in Figure 13 to the position shown in Figure 12. During this transition the flat parallelogram shape opens out to a larger parallelogram and in the standing or erect configuration of the barrier unit 1 results in a substantially rectangular configuration with the top rail 5, and the left-hand bottom rail 25 substantially parallel to each other, while the rods 20 are also substantially parallel to each other (and perpendicular to both the top rail 5 and the left-hand bottom rail 25).

[0073] Each rod 20 has, at a top end 23 thereof an open hook shape 27 defining an open mouth 28 for pivotally connecting to a top pivot 21. Each rod 20 has an open hook shape 27 defining an open mouth 28 at a bottom end thereof for pivotally connecting to a bottom pivot 22. The respective open mouths 28 of the open hook shapes of each rod face in opposite directions relative to the direction of folding (Arrow A). The respective open mouths 28 at the top ends 23 of the rods 20 face, (in the orientation of Figures 12 and 13) left. The open mouths of the open hook shapes at the top ends of the rods faces away from the direction of folding, and the open mouths of the open hook shapes at the bottom ends of the rods faces towards the direction of folding.

[0074] The respective open mouths 28 at the bottom ends 24 of the rods 20 face, (in the orientation of Figures 12 and 13) right. As can be seen from Figure 13 in particular, the respective open mouth 28, and the fact that the shapes 27 face in opposite directions, means that the hook shapes 27 do not obstruct the rods 20 coming together against each other. For example, if instead of the open hook shape, a closed collar, encircled the pivot joints, it is clear that such tight packing of the rods 20 could not be achieved because upon folding, each collar would prevent the rods coming together against each other, because a rod would first abut a collar and the rods would not fold flat against each other but would be held apart to an extent.

[0075] While Figure 12 shows the left hand foldable barrier section 8 only, it will be appreciated that the right hand foldable barrier section 9 is constructed in the same manner. Because it folds in the opposite direction to left hand foldable barrier section 8 it will be adapted to do so yet fold flat also. For example it may resemble a mirror image of Figure 12 or the configuration of Figure 12 turned through 180 degrees. The right hand foldable barrier section 9 has rods 20 and a right hand bottom rail 26.

[0076] As is desirable in every embodiment, the rights 20 rod snap fits to at least one of the top pivot and the bottom pivot and desirably both. This allows for ease of construction/assembly of a barrier unit 1 of the present invention.

[0077] The collapsible barrier unit 1 according to the present invention comprises two support legs 30, 31 on which it can stand in an erect configuration. A left hand leg 30 is provided on the left hand foldable barrier section 8 and a right hand leg 31 is provided on the right hand foldable barrier section 9.

[0078] The left hand leg 30 hangs from the top rail 5 and folds up and towards the right side 7 of the top rail 5. The right hand leg 31 hangs from the top rail 5 and folds up and towards the left side 6 of the top rail 5. They may be connected to the top rail 5 within the channel 15 in a manner analogous to the rods 20.

[0079] The collapsible barrier unit 1 according to the invention further comprises a left hand strut 35 which acts, in an erect configuration of the collapsible barrier unit, to brace the left hand leg 30 against the left side 6 of the top rail 5. The left hand strut 35 comprises a first strut portion 35a, a second strut portion 35b and a locking hinge 35c joining the first strut portion 35a and the second strut portion 35b. The left hand strut 35 locks in its bracing position (that shown in Figure 3) when the barrier unit 1 is erect. But the left hand strut 35 folds about pivot 35c to allow relative folding of first strut portion 35a and the second strut portion 35b as shown in Figures 2, 5 and 6. The collapsible barrier unit 1 according to the invention further comprises a right hand strut 36 which acts, in an erect configuration of the collapsible barrier unit 1 , to brace the right hand leg 31 against the right side 7 of the top rail 5. The right hand strut 36 comprises a first strut portion 36a, a second strut portion 36b and a locking hinge 36c joining the first strut portion 36a and the second strut portion 36b. The right hand strut 36 locks in its bracing position (that shown in Figure 3) when the barrier unit 1 is erect. But the right hand strut 36 folds about pivot 36c to allow relative folding of first strut portion 36a and the second strut portion 36b as shown in Figures 8 and 9. [0080] A first end 37 of the left hand strut 35 is pivotally attached to the left hand leg 30. A second end 38 of the left hand strut 35 is pivotally attached to upper rail 5 within the channel 15. As the left hand foldable section 8 is folded (see the sequence from Figures 3 to 9) the strut portions 35a and 35b fold and the left hand strut 35 folds into the top rail 5. It folds into and is within the channel 15 as in the configuration of Figure 1. A first end 39 of the right hand strut 36 is pivotally attached to the right hand leg 31. A second end 40 of the right hand strut 36 is pivotally attached to upper rail 5 within the channel 15. As the right hand foldable section 9 is folded strut portions 36a and 36b fold and the second end 40 of the right hand strut 39 folds into the top rail 5. It folds into and is within the channel 15 as in the configuration of Figure 1.

[0081] The left hand leg 30 and the right hand leg 31 each have a folding mechanism that allows that leg to move between a compact configuration (seen in Figures 2, and 4 to 9) for folding to a standing configuration for supporting the collapsible barrier unit, the standing configuration having an increased footprint for greater standing stability.

[0082] As best seen from Figures 11 A to 11 C the folding mechanism includes leg portions that move by splaying apart, so that each leg can move from a compact configuration for folding with the leg portions in a non-splayed position to a standing configuration for supporting the collapsible barrier unit, where the leg portions are in a splayed position for greater standing stability (the weight of the barrier unit holds the legs in the splaying position).

[0083] The left hand leg 30 and the right hand leg 31 each have a folding mechanism that includes three leg portions that can move from a compact configuration where the leg portions fold substantially flat against each other to a triangulated standing position that provides greater standing stability. The three leg portions comprise an upright leg

32 portion, a supporting leg portion 33 and a bracing leg portion 34. In the erect, position the legs portions 32, 33, 34 are in a triangulated standing position. The upright leg portion 32 and the supporting leg portion 33 splay apart to form the sides and apex of a triangle. The upright leg portion 32 is hingedly joined to the supporting leg portion

33 at hinge 43. The apex of the triangle is at hinge 43. The bracing leg portion 34 forms the base of the triangle with one end of the bracing leg portion 34 slidingly (optionally linearly) attached by slide 44 to the supporting leg portion 33 and the other end 35 for sitting on the ground. The upright leg portion 32 sits on the bracing leg portion 34 and is hingedly connected to it at a position 46 between the two ends of the bracing leg portion 34.

[0084] Figure 11A shows the erect position of the leg with the leg portions 33, 34 splayed apart from each other and with bracing leg portion 34 supporting the upright portion 32 and bracing against supporting leg portion 33. The leg portions 32 to 34 fold up as shown in the sequence from Figure 11 A through to 11 C so that they are flat and compact. As best seen in Figures 11 B and 11 C the end of the bracing leg portion 34 attached by slide 44 slides up supporting leg portion 33 while pivoting relative to upright leg portion 32 so that the three leg portions can then be folded flat as in Figure 11C. Once in the configuration of Figure 11C the leg can then be folded up into the top rail 5 as shown in the sequence from Figures 3 to 9.

[0085] A collapsible barrier unit 1 of the invention may include side members 18, 19 that fold in the same manner as rods 20 but which impart greater structural strength to the barrier unit.

[0086] A collapsible barrier unit according to the invention may comprise a tip-over prevention mechanism 50 for counteracting tip-over forces as shown in Figures 15A to C.

[0087] The tip-over prevention mechanism 50 comprises a free hanging

counterbalance 51 that is substantially aligned with the collapsible barrier unit when the collapsible barrier unit 1 is upright in an erect configuration (Figure 15A). It can pivot outwardly Figures 15B and C) with respect to the collapsible barrier unit 1 when the collapsible barrier unit 1 experiences tip-over forces such as indicated by pushing forces represented by arrows B, such as wind etc. It takes the form of a pendulum 52 which is pivotally mounted at 53 to the barrier unit 1 . The action of the pendulum is to move the centre of gravity of the collapsible barrier unit 1 , thus counteracting the tip- over forces and making it more likely that the barrier unit will return towards its standing position. Indeed, and is best seen in Figures 15C, the pendulum can also act as a prop or stay to prevent tip over by engaging the ground before the barrier unit 1 reaches a critical tip over point. This will physically prop the barrier unit against the ground, acting as a stop, and preventing tip over.

[0088] It will be appreciated that any tip over mechanism provided will fold away into the configuration of Figure 1.

[0089] Instead of the pendulum 52 the barrier unit of the invention can comprise a fixed central support leg to support the barrier unit at the middle of the top rail 5. So, instead of a pendulum 52 a central leg, in the same position as, and instead of the pendulum 52, can be provided. For example as shown in Figures 3 to 10 a fixed central leg is provided which extends from (within the channel 15 of) the top rail 5 to ground level of the barrier unit 1 . It too however can fold up when the barrier unit 1 is being folded up.

[0090] Each end of the top rail 5 has coupling for coupling a first collapsible barrier unit of the invention to a second collapsible barrier unit of the invention. The coupling comprises a male part 60 and a female part 61 and the male part and the female part are provided on opposite ends. The coupling allows a first collapsible barrier unit 1 to be attached to a second collapsible barrier unit of the invention in a straight line or at an angle relative to each other. This is simply done by inserting the male part 60 into the female part 61. The angle at which the barrier units can be arranged with respect to each other in an erect configuration can be varied while they are coupled together. The male part 60 is provided on a moveable or linkage arm 62 which can move to allow for height differences between barrier units and thus may act as a coupling hook 63 as described below.

[0091] An arrangement with a series of barrier units coupled together in a non-linear manner to form a continuous barrier is shown in Figure 10. In the arrangement in figure 10 the barrier units are coupled together (top and bottom) by coupling hooks 63.

[0092] The left-hand bottom rail 25 and the right-hand bottom rail 26 can each be independently weighted to provide stability to the barrier unit 1 in the standing position. For example each rail, 25, 26 could be hollow to accommodate ballast weight such as sand etc. Alternatively a specifically designed weight could be used to mate with the bottom rail 25, 26. For example a moulded container that can be mounted onto the base of the barrier unit may be utilised. The container could be provided with ballast such as water or sand. This would obviate the necessity to use other weights such as sandbags etc. which are cumbersome to use. The left-hand bottom rail 25 and the right-hand bottom rail 26 lock together in use in the erect configuration. Furthermore the left-hand bottom rail 25 and the right-hand bottom rail 26 can be provided with a coupling for coupling a first collapsible barrier unit 1 of the invention to a second collapsible barrier unit of the invention. The coupling may be a male part 41 and a female part 42 and one of a male part or a female part is provided on each of the first and second end, desirably wherein a male part is on a first end and a female part is on the second end. This allows for ease of meeting the barrier units together to form a continuous barrier. The coupling may allow a first collapsible barrier unit of the invention to be attached to a second collapsible barrier unit of the invention in a nonlinear manner, for example at an angle. Suitably the coupling allows a first collapsible barrier unit of the invention to be pivotally attached to a second collapsible barrier unit of the invention so that the angle at which the barrier units can be arranged with respect to each other in an erect configuration can be varied while they are coupled together.

[0093] Figure 1 shows just how compact a barrier unit 1 of the invention can be.

Figures 14A and 14B further demonstrate this. A division between the front and rear sections is optional and indicated by broken line 4. Figure 14A is a schematic representation in sectional view of the parts within the channel 15 in the erect or standing configuration of the barrier unit or module 1 .

[0094] As is demonstrated by Figure 14B it is desirable that parts that fold together are hollow section such as U-section or H-section in shape. This allows for more compact packing.

[0095] The side members 18,19 are U-shaped and this means that one or more rods 20 can be accommodated within their profile. Furthermore the legs 30, 31 each have a U-shape or H-shape allowing the side members 18,19, rods 20 and bottom rails 25, 26 to be accommodated within the profile of the legs. In turn this compact configuration can be packed into the channel 15 and thus the entire barrier unit 1 remains within the profile of the top rail 5 as clearly seen in Figure 14B.

[0096] The words "comprises/comprising" and the words "having/including" when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0097] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in

combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.