The invention relates to barriers. In particular, though not exclusively, the invention relates to impact barriers such as vehicle impact barriers.

Rapidly deployable barriers exist typically in a form suitable for use with pedestrians or the like and comprise light-weight posts between which light-weight ropes, beams or other barrier elements extend. However, the light-weight property of such barriers often means that they are not robust and are wholly unsuitable for use in resisting significant transverse forces, such as vehicular impact forces.

Conversely, vehicle impact barriers are typically not only very heavy but also permanent, or semi-permanent in form, and cannot be rapidly deployed and subsequently removed. The invention aims to provide a barrier, such as a vehicle impact barrier, which may address these deficiencies.

At its most general, the invention is to provide a barrier, such as a vehicle impact barrier, adapted to detachably fit to a pair of pre-existing, separate foundation parts (e.g. posts, stanchions, bollards) to provide a barrier which extends between those separate foundation parts. The barrier may comprise two adaptor parts arranged to detachably fit to a respective one of two foundation parts, and a barrier line (e.g. rope, chain or the like) arranged to fit to each of the adapter parts (detachably from one or each adaptor part) concurrently so as to extend between the foundation parts (e.g. raised above ground level) to provide a barrier. This means that the barrier line need only be adapted to fit detachably to the adaptor(s) without being required to detachably fit to the pre-existing foundation parts - the adaptor parts taking care of that. Preferably, the barrier includes a bridging line arranged to extend between the two adaptor parts, in use, for supporting the barrier line by suspending the barrier line from it between the adaptor parts. This permits a heavy barrier line to be suspended at a suitable height above ground level to provide a barrier and overcomes barrier line sag. The barrier line may be suspended at different distances below the bridging line along the length of the bridging line - e.g. closer to the bridging at the middle of the bridging line so as to mirror curvature of the ground level below the barrier line (e.g. road camber) to maintain a generally uniform (approx.) height of the barrier line above the ground surface in question. The barrier line may moveably suspended from/along the bridging line to allow the barrier line to be moved along the bridging line between the two adaptor parts. A heavy barrier line me be "run" along the suspending bridging line (e.g. in the manner of a curtain along a curtain rail) to open and close the barrier as desired, without having to manually carry the heavy barrier line. In a first aspect, the invention may provide a barrier apparatus comprising a first support assembly and a separate second support assembly; a flexible coupling member (e.g. barrier line) coupled to the first support assembly; and, a bridging member extending from the first support assembly to the second support assembly. The bridging member (e.g. bridging line) supports the flexible coupling member and the flexible coupling member is moveably attached thereto to be moveable along the bridging member for coupling to the second support assembly thereby to define a barrier comprising the flexible coupling member which extends between the first support assembly and the second support assembly. Each of the first and second support assemblies includes a respective first and second foundation member and a respective first and second adaptor assembly detachably mounted upon the foundation member wherein the bridging member is attached to said first and second adaptor assemblies to permit disassembly of the barrier from the first and second foundation members and reassembly thereof using the first and second foundation members. The bridging member may be a cable, wire or rope. The coupling member may comprise a cable, wire or rope (or a combination thereof). The coupling member may comprise multiple separate coupling lines connected in parallel such that one or more coupling members are suspended from an upper coupling member, in use. The bridging member is preferably detachably attached to one of the two adaptor assemblies. In this way, the coupling member may be detached from either or both adaptor assemblies as desired.

One of the two adaptor assemblies may include a tensioning assembly arranged for adjusting the tension in the bridging member extending between the adaptor assemblies. The bridging member is preferably a flexible bridging line. The bridging line may be coupled to a winching mechanism attached to one of the two adaptor assemblies and adapted to apply/release tension to the line when the concurrently attached to the other of the two adaptor assemblies - i.e. by drawing in/out a portion of the line. Alternatively, a ram or actuator may be coupled to the bridging line (e.g. an end) arranged to controllably apply tension to the line by movement of the ram/actuator - e.g. to pull/stretch the line.

The flexible coupling member may include a through-opening adapted and arranged to receive the bridging member to pass therethrough when moved along the bridging member, and to receive the second support assembly (e.g. second adaptor) to pass therethrough when coupled thereto. The flexible coupling member may include a through-opening adapted and arranged to receive the first support assembly (e.g. the first adaptor) to pass therethrough when coupled thereto. The through-opening may be an eye, loop or hook formed in the coupling member (e.g. a loop in a rope end) The bridging member preferably includes an elongate member extending from the first support assembly to the second support assembly. The bridging member may comprise a length of cable, wire, rope or other flexible element. Preferably the bridging member also includes a shuttle part attached moveably upon the elongate member to travel therealong. The shuttle part is preferably adapted to carry the coupling member via said through-opening to convey the through-opening along the elongate member. The shuttle part is preferably attached or mounted moveably upon the elongate member via wheels located at opposite sides of the elongate member arranged to travel therealong.

The bridging member may include one or more suspender parts attached moveably upon the elongate member via wheels located at opposite sides of the elongate member arranged to travel therealong, and attached to the coupling member to suspend the coupling member from the elongate member.

The flexible coupling member preferably includes a through-opening adapted and arranged to receive the second adaptor assembly to pass therethrough for coupling thereto. Preferably, the second adaptor assembly is rotatingly mounted to the second foundation member and comprises a cam part rotatable by said rotation to urge against the received through-opening in a direction away from the first support assembly thereby to increase the tension within the flexible coupling member.

One or each of the first and second adaptor assemblies may include an adjustable attachment assembly adjustable to engage a surface of the respective first or second foundation member to attach the adaptor assembly thereto by gripping.

Preferably, one or each first and second foundation member is a fixed stanchion or bollard.

The invention may be made and sold in kit form. Thus, in a second aspect, the invention may provide a kit of parts for a barrier apparatus detachably mountable upon both a first foundation member and a separate second foundation member concurrently, to define a barrier extending therebetween comprising a first adapter assembly arranged to detachably attach to the first foundation member and a separate second adaptor assembly arranged to detachably attach to the second foundation member to permit assembly of the barrier using the first and second foundation members, a flexible coupling member arranged for coupling to the first adaptor assembly and to the second adaptor assembly concurrently so as to extend therebetween thereby to define a barrier comprising the flexible coupling member and, a bridging member connected to (or arranged to be connected to) the second adaptor assembly and extendable from the second adaptor assembly to detachably attach to the first adaptor assembly. The bridging member is arranged to support the flexible coupling member between the first adaptor assembly and the second adaptor assembly in the barrier and the flexible coupling member is moveably attached to the bridging member to be moveable along the bridging member. One of the two adaptor assemblies preferably includes a tensioning assembly arranged for adjusting the tension in the bridging member when extending between the adaptor assemblies.

The flexible coupling member preferably includes a through-opening adapted and arranged to receive the bridging member to pass therethrough, and to receive the second adaptor assembly to pass therethrough when coupled thereto.

The bridging member may include an elongate member and a shuttle part attached moveably upon the elongate member to travel therealong and adapted to carry the coupling member via said through-opening to convey the through-opening along the elongate member.

The shuttle part is preferably attached moveably upon the elongate member via wheels located at opposite sides of the elongate member arranged to travel therealong.

The bridging member may include an elongate member and one or more suspender parts attached moveably upon the elongate member via wheels located at opposite sides of the elongate member arranged to travel therealong, and attached to the coupling member for suspending the coupling member from the elongate member.

The flexible coupling member preferably includes a through-opening adapted and arranged to receive the second adaptor assembly to pass therethrough for coupling thereto, wherein the second adaptor assembly is rotatingly mountable to the second foundation member and comprises a cam part rotatable by said rotation to urge against the received through-opening in a direction away from the first adaptor assembly, in use, thereby to increase the tension within the flexible coupling member.

One or each of the first and second adaptor assemblies may include an adjustable attachment assembly adjustable to engage a surface of the respective first or second foundation member to attach the adaptor assembly thereto by gripping. In a third aspect, the invention may provide a method of providing a barrier apparatus comprising: detachably attaching a first adapter assembly to a first foundation member and detachably attaching a separate second adaptor assembly to a second foundation member concurrently, extending a bridging member (e.g. line) between the first and second adaptor assemblies to attach to both adaptor assemblies, supporting a flexible coupling member (e.g. line) between the first adaptor assembly and the second adaptor assembly via the bridging member (e.g. by suspension) wherein the flexible coupling member is moveably attached to (e.g. suspended from) the bridging member to be moveable along the bridging member, coupling the flexible coupling member to the first adaptor assembly and to the second adaptor assembly concurrently so as to extend therebetween thereby to define a barrier comprising the first and second adaptor assemblies attached to the first and second foundation members respectively, and the supported flexible coupling member extending therebetween.

Preferably, the coupling member comprises one or more coupling lines such as rope, chain, cable, wire etc. Most preferably, the coupling member is rope. Its weight is supported by the bridging member (e.g. line, such as cable, wire or rope). It has been found that nylon ropes, particularly plait ropes (e.g. "Nylon 12 Plaid" rope or "Plasma 12 Strand" rope or other ropes produced by Puget Sound Rope, of 1012 Second Street, Anacortes, WA 98221 USA), are suitable for use in the coupling member. Their % Elongation vs. Load characteristics make them suitable for absorbing and dispersing impact energies by stretching (not excessively) when subject to impact loads. Barriers of different strengths can be constructed by using a variable number of identical or similar elements. The rope(s) may be generally elliptical in cross section and may have a length of about 4 m. They are preferably terminated with loops in the form of eyelets which may fit over the adaptor parts, or over obstruction shafts/pins thereon, in this way to indirectly fit to the pre-existing foundation parts (stanchions/bollards/supports).

The rope may have an elongation at breaking point of at least 25%. The combined spring constant of the rope is desirably greater than 4000 kN/m preferably in order to stop a vehicle travelling at speed.

Two designs may be employed, one based on Plasma (identified above) rope spiraled on a rubber core and the other using 68 mm nylon rope (identified above). The spiral configuration is preferable with Plasma rope because the extension at breaking point is typically about 2%. Nylon rope has an extension at breaking point of about at least 30%. The nylon rope design may be desirable because it does not require a core, it is easier to construct and does not depend on an accurately-determined lay length.

There now follows a description of non-limiting examples of the present invention which embody implementations of the inventive concept with reference to the accompanying drawings of which:

Figure 1 illustrates a barrier apparatus according to a preferred embodiment of the invention; Figure 2 illustrates a cross-sectional view of two support assemblies of the apparatus illustrated in Figure 1 ; Figure 3 illustrates a magnified view of the head end of the second support assembly of

Figure 2, in cross-section, showing elements of the bridging apparatus;

Figures 4 and 5 show views of the head end of the adaptor assembly of the second support assembly in two states of operation, those being the non-gripping state (Figure 4) and the gripping state (Figure 5);

Figure 6 illustrates the adaptor assembly of Figure 5 in situ upon a bollard stanchion and in the gripping state; Figures 7 and 8 illustrate views of the second adaptor assembly including a pair of cams and flexible coupling ropes coupled thereto;

Figure 9 illustrates the second adaptor assembly in a rotated state whereby the cams urge tension in the two flexible coupling ropes coupled to them;

Figure 10 illustrates a cross-sectional view of the arrangement of Figure 9;

Figure 1 1 illustrates a view of the first adaptor assembly with two flexible coupling ropes in situ;

Figure 12 schematically illustrates the barrier apparatus with two coupling ropes in situ tensioned by cams upon the second adaptor assembly;

Figure 13 shows an alternative arrangement of a cam assembly on the second adaptor assembly;

Figure 14 shows an alternative arrangement of the first adaptor assembly. In the drawings like articles are assigned like reference symbols for consistency.

Figure 1 illustrates a barrier apparatus according to a preferred embodiment of the invention, the barrier apparatus being in fully assembled state. The barrier apparatus (1) comprises a first support assembly (2) and a second support assembly (3) coupled together by a flexible coupling rope assembly (4) extending from the first support assembly to the second support assembly.

A bridging cable (5) extends from the first support assembly (2) to the second support assembly (3) directly above the coupling rope assembly (4). A plurality of suspension runners (15) are separately attached moveably upon the bridging cable (5) and are arranged to freely run along the length of the bridging cable between the first and second support assemblies. The lower portion of each suspension runner possesses a suspension line (16), such as a strap which may be adjustable in length, which depends from the suspension runner and attaches to an uppermost rope (1 1) of the coupling rope assembly (4) of the barrier. In this way, each suspension runner is moveable along the length of the bridging cable to a desired position whereat it suspends the coupling rope assembly below the bridging cable at a desired height determined by the adjustable length of the suspension line (16). Each suspension runner is attached to the bridging cable via an array of three or more wheels positioned such that two upper wheels (15A) engage one side (the upper side in use) of the bridging cable while the third underside wheel (15B) engages the opposite side (e.g. underside) of the suspension cable concurrently at a position between the opposite two wheels. This array of three wheels is held in position by, and between, a pair of oppose runner plates such that the bridging cable passes between the oppose runner plates and concurrently between the opposing upperside and underside wheels thereof. In this way, the suspension runner is prevented from disengaging from the bridging cable in a direction transverse to the cable. A shuttle part (19) is attached moveably upon the bridging cable adjacent the second support assembly and is arranged to travel along the bridging cable between the first and second support assemblies. The shuttle part comprises a pair of opposed shuttle plates joined together by, and spaced by, two separate pairs of shuttle wheels. In each of the two pairs of shuttle wheels, one wheel (19A) of the pair is separated from the other wheel (19B) of the pair by a spacing arranged to closely receive the bridging cable such that the wheels of the pair engage the cable at opposite sides of the cable. The two pairs of wheels are spaced longitudinally along the body of the shuttle part such that the bridging cable passes between the wheels of each pair of wheels to extend along and beyond the shuttle part. This arrangement of wheels prevents the wheels of the shuttle part from disengaging from the bridging cable in a lateral direction.

The opposed plates of the shuttle part are substantially the same in shape and structure and are arranged in register with one another. The lateral edges of the two shuttle plates define a saddle recess, one at each lateral side of the shuttle part which is shaped and dimensioned to accept a part of a loop-end of one or more of three separate rope portions (1 1 , 12, 13) of the coupling rope assembly (4) as will be described in more detail below. The shuttle part is adapted to travel along the bridging cable to carry the loop ends of the coupling rope assembly and convey the loop ends of the rope assembly along the bridging cable from the second support assembly towards the first support assembly thereby to open the barrier in use, and to convey the coupling rope assembly in the reverse sense to re-close the barrier as desired. The shuttle part is arranged to be pushed against an adjacent suspension runner (15) as it is pushed along the bridging cable towards the first support assembly thereby to push the suspension runner along the bridging cable together with it, and all subsequent suspension runners arranged along the bridging cable between the shuttle part and the first support assembly may be gathered up and pushed to the first support assembly by the shuttle part thereby to clear the majority of the bridging cable of rope and suspension runners.

The bridging cable (5) is attached to the second support assembly via a winding assembly such as a winch mechanism (17) manually operable via a crank handle (17B) to turn either to draw the cable towards the winch to wind parts of the bridging cable onto the winch, or to unwind lengths of the bridging cable from the winch. The bridging cable is attached to the winding assembly (17) in such a way that only by such rotational operation can bridging cable be extended from or retracted onto the second support assembly. The terminal end of the bridging cable is detachably attached to an attachment loop (18) fixed to the head end of the first support assembly (2). The terminal end of the bridging cable may be detached from the attachment loop (18) of the first support assembly and the detached length of cable may subsequently be retracted onto the winding assembly as desired if/when disassembling the barrier.

Conversely, in assembling the barrier, a length of bridging cable may be extended from the winding assembly to such an extent as to allow the terminal end of the bridging cable to attach to the attachment loop (18) on the first support assembly, and the winding (17) appropriately operated to retract an amount of cable back onto the winding assembly in order to increase the tension within the bridging cable to a desired or maximum amount, such as is shown in Figure 1 . A locking mechanism, such as a ratchet and pawl mechanism, may be included in the winding assembly to permit the tensioned state to be maintained by not permitting the winding assembly to subsequently unwind until required to do so. Each of the first and second support assemblies (2, 3) comprises a respective first and second foundation member (7, 9) which comprises a fixed ground-mounted bollard providing, respectively, one of a pair of stanchions. Each support assembly further includes a respective first and second adaptor assembly (6, 8) comprising a tubular sheath detachably mounted upon the respective stanchion. Each of the first and second adaptor assemblies includes an internal adjustable attachment assembly which is adjustable to engage a surface of the respective stanchion sheathed by the adaptor assembly, in order to engage a surface of the stanchion to attach the adaptor sheath to that stanchion by gripping it. This is discussed in more detail with reference to Figures 2 to 4 below.

Returning to Figure 1 , the rope coupling assembly (4) comprises three separate rope members (1 1 , 12, 13) each comprising an elongate length of rope terminated at each end by a spliced loop end defining a through-opening at that end shaped and dimensioned to closely fit over the outer surface of either one of the first and second adaptor assemblies (2, 3). The uppermost rope length is suspended from the bridging cable via the suspension lines (16) depending from cable runners (15) as described above. Similarly, a second (12) intermediate length of such rope is suspended from the underside of the uppermost length of rope by intermediate suspension lines (14) which connect the two rope lengths. Finally, a third (13) and lowermost rope length is suspended from the intermediate rope length by further intermediate suspension lines (14) which connect the intermediate rope length to the lowermost rope length. In this way, the entire rope coupling assembly is ultimately suspended from the bridging cable (5) extending from the first adaptor assembly (6) to the second adaptor assembly (8).

In order to open the barrier, a user may raise the end loop (1 1 A) of the uppermost rope length which engages the second adaptor assembly and pass the loop over the head of the second adaptor assembly, past the winding assembly (17) and along the bridging cable (5), such that the bridging cable passes through the through-opening of the end loop (1 1 A), and then rest the end loop into the recess formed by the upper edges of the shuttle part (19). This operation should be concurrently performed on all three of the end loops (1 1A, 12A, 13A) of the upper, intermediate and lower rope lengths (1 1 , 12, 13). Once in place upon the shuttle part, the end loops of the three rope lengths may be conveyed by the shuttle part along the bridging cable towards the first adaptor assembly (6) thereby to retract the coupling rope assembly. Once there, the winding mechanism (17) at the head of the second adaptor assembly may be turned to reduce the tension in the bridging cable to an extent sufficient to allow the bridging cable to rest on the ground surface (10) between the first and second support assemblies.

In this way, the winding mechanism is turned in such a way as to release sufficient bridging cable to allow the bridging cable to simply rest on the ground surface between the first and second adaptor assembly with all of the suspension trolleys and the shuttle part still engaged upon the un-retracted bridging cable. A vehicle may then pass through the barrier between the first and second support assemblies, being required only to drive over the loose and unoccupied length of bridging cable extended from the turning mechanism (17). In order to re-erect the barrier, the winding mechanism (17) is then turned in such a way as to retract cable onto it in order to fully tension the bridging cable between the first and second adaptor assembly. This raises the shuttle part (19) and the suspension runners (15) and concurrently re-suspends the rope assembly (4). The shuttle part (19) is then pushed along the re-tensioned bridging cable from the first adaptor assembly to the second adaptor assembly at which point each of the three end loops (1 1 A, 12A, 13A) of the upper, intermediate and lower rope lengths (1 1 , 12, 13) are dismounted from the shuttle part and put back in place around the body of the second adaptor assembly as shown in Figure 1 .

Alternatively, should the user wish to fully disassemble the barrier, rather than re-erect it, the terminal end of the un-tensioned bridging cable is disengaged from the attachment loop (18) at the head of the first support assembly, and second end loops (1 1 B, 12B, 13B) which loop around the outer surface of the first adaptor assembly (6) are disengaged and separated from the first adaptor assembly to disengage the coupling rope assembly from the first and second support assemblies. The first and second adaptor assembly (6, 8) may then be disengaged from the first and second bollard stanchions respectively (7, 9). The first and second adaptor assemblies would simply be disengaged from the stanchions within them, and lifted off those stanchions to reveal those stanchions in their normal or natural state. This would ideally be done when the rope assembly (4) is fully detached and optionally with the bridging cable fully retracted onto the winding assembly (17).

Referring to figure 2 there is shown cross-sectional views of the first and second support assemblies revealing how the first and second adaptor assemblies may couple to the first and second ground-mounted bollard stanchions (7, 9) respectively.

Each of the first and second adaptor assemblies (6, 8) comprises a cylindrical sleeve part (28, 26) within which is mounted a coupling frame assembly (20, 29) each comprising four hollow box-section elongate tubes (20, 30) arranged in parallel in a square array having a longitudinal axis coaxial with the cylindrical axis of the sleeve within which they mounted. The diameter of the cylindrical sleeve parts is sufficient to admit the transverse dimensions of a ground- embedded bollard stanchion (7, 9) along substantially its whole above-ground length. Similarly, the four parallel tubes of each coupling frame assembly are held in parallel separation by an upper separator plate (31 , 23) and a pair of lower separator plates (32, 33). A common square array of four square through-holes is formed in each of the three separator plates of each coupling frame. The array of through-holes in any one of the three separator plates is positioned in register with each array of the other two arrays of through-holes in the other two separator plates of the same coupling frame. Each one of the four hollow box- section elongate tubes separately passes through, and is welded to, each one of a respective three co-registered through-holes on the three separator plates of a coupling frame in succession to join the three separator plates rigidly. The square array of box-section tubes is dimensioned to admit the transverse dimensions of a ground-embedded bollard stanchion (7, 9) along substantially its whole above-ground length. Opposing pairs of adjustable coupling bolts (35, 36) extend adjustably from the lower pair of separator plates in a direction towards the central axis of the respective coupling frame so as to be able to engage and urge against opposite sides of the surface of the bollard stanchion when located therebetween. Each coupling bolt passes through a respective threaded bolt hole formed through a respective upstanding plate part fixed to one or each of the two separator plates of the lower pair of separator plates. The upstanding plate parts are arranged to present the respective bolt hole to towards a surface of the bollard stanchion in use. The coupling bolts are arranged to fit to and adjustably pass through the respective threaded bolt holes to engage the bollard stanchion at their free end, being adjustable via a spanner or the like at their bolt-head ends. This enables the lower end of the coupling frame to grip the lower end of the bollard stanchion between them to hold the coupling frame to the stanchion.

Opposing pairs of adjustment bolts (37) extend from the upper separator plates of the coupling frames in a direction towards the central axis of the respective coupling frame. Each adjustment bolt passes through a respective bolt hole formed through a respective uppermost upstanding plate part (38) fixed to the upper separator plate. The uppermost upstanding plate parts are arranged to present the respective bolt holes towards a surface of the upper parts of the bollard stanchion in use. The adjustment bolts are arranged to pass through the respective bolt holes being able to turn within the respective bolt hole but being prevented from moving though/along the bolt hole. The adjustment bolts do not engage any threading (if any) within the respective bolt holes. A threaded retaining nut (42) is mounted upon the shaft of each respective adjustment bolt at a side of the respective bolt hole opposite to the side against which the head of the bolt turnably rests. This arrangement of retaining nut and bolt head holds the length of the adjustment bolt in place relative to the uppermost upstanding plate part by sandwiching the latter between them.

Concurrently, a pair of opposed L-plates is mounted upon the upper separator plate of each coupling frame. Each L-plate is L-shaped in cross section and comprises an upstanding plate part joined to a sliding plate part which extends transversely from the upstanding plate part in a direction parallel to the upper surface of the upper separator plate to which it is slidingly coupled. Each L-plate is slidingly coupled to an upper separator plate to permit it to be adjustably slid thereover in a direction towards the bollard stanchion housed within the coupling frame, in use, to engage the bollard stanchion at the free end of the sliding plate part. In particular, a threaded through-hole provided in the upstanding plate part (39) of the L-plate is dimensioned to engage the threading of the parts of the adjustment bolt (37) which extend from the upstanding plate part (38) of the upper separator plate beyond the retaining nut (42). By turning the adjustment bolt (37), the L-plate is urged to slidingly move along the shaft of the turning adjustment bolt (37) and thereby more towards or away from the housed bollard stanchion (9) according to the direction in which the adjustment nut is turned. The adjustment bolts are adjustable via a spanner or the like at their bolt-head ends. This enables the two opposed L-plates to grip the upper end of the bollard stanchion between them to hold the coupling frame to the stanchion.

Figure 3 shows the opposed L-plates in the gripping position in which they are slid by suitable adjustment of adjustment bolts (37) towards and against opposite sides of the bollard stanchion. In the example shown, the opposite sides of the bollard stanchion present a series of parallel horizontal grooves into which the terminal edge of the sliding plate part is dimensioned to fit by said sliding action to anchor the L-plates to the stanchion. The bollard is known as a "City of Westminster" bollard. It is typically solid metal. Figure 4 shows the opposed L-plates in the open position in which the bollard stanchion (omitted for clarity) is not gripped, while Figure 5 shows the opposed L-plates in the closed state (such as in Figure 3) in which the bollard stanchion (not shown for clarity) is gripped.

The L-plates are each retained upon the upper separator plate of the respective coupling frames via a respective bolt (40) passed through the upper separator plate from its underside and onwards through an adjustment slot (43) formed through and extending along the sliding plate part of the respective L-plate in a direction of sliding adjustment of the L-plate - namely, the direction from the adjustment nut (37) to the central axis of the coupling frame. A retaining nut is threaded upon the bolt above the adjustment slot. The diameter of the retaining nut exceeds the lateral width of the adjustment slot thereby to prevent the adjustment slot being lifted past the retaining nut. This restrains the sliding plate part of each L-plate both horizontally/laterally and vertically.

Returning to Figure 2, the cylindrical body (28) of the first adaptor assembly (6) is topped by a top plate (27) which is fixed to the head end of the first adaptor assembly to close it. The attachment loop (18) is fixed to and upstanding from the uppermost surface of the top plate. Accordingly, the first adaptor assembly is detachably coupled firmly to the first bollard stanchion (7) via the coupling bolts (35) at the lower end of the coupling frame (30) thereof, and via the L-plate parts (39) at the upper end of the coupling frame.

The attachment loop (18) is fixed to and upstanding from the uppermost surface of the top plate. Accordingly, the first adaptor assembly is detachably coupled firmly to the first bollard stanchion (7) via the coupling bolts (35) at the lower end of the coupling frame (30) thereof, and via the L-plate parts (39) at the upper end of the coupling frame.

Similarly, the cylindrical body (26) of the second adaptor assembly (8) is topped by a top plate assembly (44) which is not fixed to the head end of the first adaptor assembly but, rather presents uppermost an array of four rotatable bearing wheels (46) evenly spaced around the central longitudinal axis of the coupling frame of the second adaptor assembly for bearing the underside surface of the outer cylindrical body (26) at an annular head ring (25) is fixed to the circular peripheral edge of the head end of the cylindrical body of the second adaptor part and extends partially overt the bore of the second adaptor part leaving a through-opening defined by the central circular opening of the annular head ring centred upon the central longitudinal axis of the coupling frame. In this way, the cylindrical body of the second adaptor assembly (25, 26) is mounted rotatingly upon the coupling frame (20) thereof so as to be rotatable about its cylindrical axis. The axles (47) of the bearing wheels are aligned to extend radially from the cylindrical axis so that the wheel bearings turn directly in alignment with the rotation of the underside surface of the annular head ring against which they bear, when the annular head ring rotates as the cylindrical body of the second adaptor assembly is revolved about its axis.

The top plate assembly (44) includes a raised circular support plate (45) positioned above, but not over, the uppermost parts of the wheel bearing surfaces. The diameter of the raised support plate is less than, but closely similar to, the diameter of the central circular opening of the annular head ring (25). The annular head ring is therefore adapted to rest upon the adaptor assembly via the four rotatable bearing wheels (46) and thereat to bear the weight of the cylindrical body (26) of the cylindrical sheath rotatably mounted upon the adaptor frame (20). In Figure 6, the cylindrical body part (26) of the sheath is omitted for clarity, as is one of the box-section elongate tubes (20) of the coupling frame. This permits a clear view of the L- plates via which the adaptor frame assembly grips the outer surface of the "City of Westminster" bollard illustrated in Figure 6. The winch unit (17) is fixably mounted to the uppermost surface of the raised circular support plate (45) via screws of the like to rigidly fix the former at the top of the latter. The winch unit is therefore centrally aligned to the axis of the adaptor assembly at the top of the adaptor assembly. A crank handle (???) may be inserted into a receiver hole formed in the uppermost end surface of the winch assembly via which the winch assembly may be turned to put effect to a winching action. Winching and crank apparatus as would be readily apparent to the skilled person may be employed for this purpose. The bridging line (5) illustrated in Figure 1 is omitted from Figure 7 for clarity, and is also omitted from Figure 8 to 40 for the same reasons. However, it is to be understood that, in use, bridging cable would be extendibly and retractably wound around the winch unit (17) as described above. A through-opening (51) is formed through the annular head ring (25) and is dimensioned to receive a cylindrical rod (50) to pass through it from above the annular head ring, externally, and into the inner box-section bore of either one of two diametrically opposed box-section elongate tubes (20) of the coupling assembly. This permits the box-section tubes to serve as storage receptacles for the majority of length of the cylindrical rod (50) as is shown in Figures 6, 7, 8 and 9. A paid of diametrically opposed notches (52) is formed in the peripheral circular edge of the coupling plate (49) via which the winch unit (17) is fixtedly mounted to the circular support plate (45). The semi-circular notches (52) are aligned in register with the central axis of the bore of each respective one of the two diametrically opposed box-section elongate tubes (20). The annular head ring (25) is rotatable from a first position as shown in Figure 7 in which the through-opening (51) formed in the annular head ring is in register with a first of the two semi-circular notches, to a second position shown in Figure 8 in which it is aligned in register with the second of the two diametrically opposed semi-circular notches. In either position, the cylindrical rod (50) may be passed through the through-opening (51) in the annular head ring and into the bore of the underlying box-section elongate tube (20) of the coupling assembly. In either position, the shaft of the cylindrical rod (50) fills the recess of the semi-circular notch (52) with which the through-opening is in register at the time. In this way, the housing of the elongate cylindrical rod (50) within the bore of a box-section elongate tube in either one of the first and second positions illustrated in Figures 7 and 8, serves to retain or lock the cylindrical body (26) into that respective position. The length of the cylindrical rod (50) may desirably be of the order of half a metre in length or of such length as is desired to enable the rod to apply sufficient torque to turn the cylindrical body of the adaptor assembly as follows. A pair of opposed upstanding flanges (53) are fixed to the uppermost surface of the annular head ring (25) to one side of the winch unit (17) such that through-openings formed in each of the upstanding flanges may present to each other without obstruction, and in register. These through-openings are dimensioned to receive concurrently a part of the cylindrical length of the cylindrical rod (50) concurrently. With the cylindrical rod so received in each of the two opposing flanges, a transverse force may be applied to the rod in order to apply a torque to the cylindrical outer sheath (25,26) of the adaptor assembly so as to turn the adaptor assembly about its cylindrical axis, by revolving or rolling the annular head ring (25) over the underlying bearing wheels (46). In this way, the outer cylindrical sheath (25,26) of the adaptor assembly may be rotated about its axis from the first position shown in Figure 7 to the second position shown in Figure 8. In either position, the cylindrical rod (50) may be returned to its housed position as shown thereby to hold the cylindrical sheath in the position shown. Internal axial roller bearings (22,34) are positioned on the coupling frame (20) in a circular array centred on the axis of the adaptor assembly. A first uppermost array is positioned adjacent the top plate assembly (22) and a lower such array (34) is positioned between the lower separator plates (32,33). These roller bearings assist in maintaining the orientation of the cylindrical sheath during rotation.

Figures 7 to 10 show a preferred embodiment of the invention in which the second support assembly (3) comprises a cam formation (55) fixed to the outer cylindrical surface of the second support assembly (26) and arranged to rotate with rotation of the latter. The cam assembly is positioned such that in the first lockable position of the cylindrical sheath of the second support assembly, shown in Figures 7 and 9, the cam formation extends towards the first support assembly (2), whereas in the second position of the rotatable cylindrical sheath (26) of the second support assembly, the cam formation (55) is presented in diametrically the opposite direction. The result is to increase the separation between the opposite loop ends (1 1A and 1 1 B; 12A and 12B) of the uppermost two of the three separate rope portions (1 1 , 12) of the rope assembly extending between the first and second support assemblies. This increases the tension of those lengths of rope and also reduces sag in the mid sections of those lengths of rope between the support assemblies. This also permits tension to be reduced along those lengths of rope prior to un-hooking the loop-ends of those lengths of rope from the second support assembly when opening the barrier as described above.

Figure 10 shows a cross-sectional view of the tensioned position of the cam formation also shown in Figure 8.

The cam formation comprises two firm but resiliently deformable eccentric or bulge parts (such as rubber) which each present a smooth curved surface which extends tangentially from the cylindrical surface of the cylindrical sheath of the second adaptor assembly. The resilient deformability of the eccentrics enables then to assist in absorbing shock loads applied to them via the rope assembly (4) when it is subject to vehicular impact.

The two eccentric parts are arranged in register with each other side-by-side axially along the outer curved surface of the cylindrical body of the second adaptor assembly. Each is housed between (and fixed to) a respective two of three spaced retention plates (56) fixed to the outer surface of the second adaptor assembly to project in a direction perpendicular to that surface by a distance exceeding the extent of the eccentrics, thereby to project beyond the outer extent of the eccentrics. The result is to define a pair of saddles or recess formations centred upon the respective two eccentric parts of the cam formation within which to receive and removeably retain a loop end (1 1 A, 12A) of the rope assembly (4).

Similarly, referring to Figure 1 1 , three spaced retention plates (57) are fixed to the outer surface of the first adaptor assembly furthest from the second adaptor assembly to project in a direction perpendicular to that surface (and away from the second adaptor assembly) thereby to define a pair of saddles or recess formations within which to receive and removeably retain a loop end (1 1 B, 12B) of the rope assembly (4).

Figure 12 shows two the tensioned loop-ended ropes (1 1 , 12) extending between the first and second adaptor assemblies in use, with terminal loop-ends suitably saddled.

Figure 13 illustrates an alternative embodiment in which the cam formation of the second adaptor assembly in which two resiliently deformable cam wheels (59, 60) are rotatingly mounted eccentrically adjacent the outer cylindrical surface of the second adaptor assembly (8) upon a respective axle extending between a respective pair of retention plates (58), and being rotatable freely about respective axes (and axles) parallel to the axis of rotation of the cylindrical sheath (8) of the second adaptor assembly (i.e. its cylindrical axis). The cam wheels are thereby able to rotate under, and bear against the inner surface, of a loop-end (1 1 A, 12A) of a length of rope of the rope assembly (4) as the sheath of the second adaptor assembly is rotated to tension the rope lengths as described above. The cam wheels may comprise an outer circular wheel surface part rotatingly mounted to an axle via spoke formations, or via intermediate deformable material, such that the wheel parts are deformable towards the spoke formations or intermediate material, when subject to shock to assist in absorbing shock loads applied to them via the rope assembly (4) when it is subject to vehicular impact. The wheel parts may be formed from a rigid plastic material, the spoke formations may be plastic, and the intermediate material may be rubber or other suitable shock-absorbing firm material.

Similarly, referring to Figure 14, in another embodiment six spaced annular retention plates (61) are fixed circumferentially to the outer surface of the first adaptor assembly (6) to project in all directions perpendicular to that surface thereby to define three separate circumferential channel or recess formations within which to receive and retain a respective one of the three loop ends (1 1 B, 12B, 13B) of the rope assembly (4 - not shown). Retaining bolts (62) join an uppermost pair, an intermediate pair and a lowermost pair of the six annular retention plates at their peripheral edges.

The retaining bolts are extend between the opposing plate surfaces of each plate pair to define an annular cage formation for retaining the respective loop end between the plates of the pair, but being sufficiently spaced to permit the length of the respective rope to pass beyond the cage formation. Each such annular cage formation comprises six retention bolts spaced evenly about the circumference of the plates of the pair of pates they join. The retention bolts are removeable to permit the respective loop ends to be removed from the first coupling assembly (6). The above embodiments are intended as examples only and it is to be understood that modifications, variants and equivalents of the above examples such as would be readily apparent to the skilled person are encompassed within the scope of the invention, e.g. as defined by the claims.