|
(11) | EP 0 649 953 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
|
|
|
|
|||||||||||||||||||||||||||
| (54) | Lockable linkage assembly |
| (57) A lockable linkage assembly comprises a first linkage member (1) having a slot into
which can be inserted an end section of a second linkage member in the form of a tongue
(9). The tongue includes a recess which engages an edge of the slot to retain the
two together. A locking member in the form of a locking tongue (17) is insertable
in the slot to thereby lock the tongue in the slot until the locking member is withdrawn. |
[0001] The present invention relates to a lockable linkage assembly of a general type particularly suited to use with temporary and permanent traffic signs, although the linkage assembly in accordance to the present invention has many uses as will be apparent to those skilled in the art and is not limited to temporary traffic signs or temporary traffic barriers.
[0002] Temporary traffic barriers and traffic signs are well known features of road maintenance and have become progressively more sophisticated as traffic speeds increase and road and motorway maintenance becomes more complex. Temporary traffic barriers are utilised to denote the edge of works on the motorway, but are also used by public utilities to prevent the public from inadvertently falling into holes, and during exhibitions, festivals etc to denote the edges of public access.
[0003] Such temporary barriers should be readily erected and dismantled, and provide a suitable barrier which it is relatively difficult to cross and prevents at least inadvertent access to an area.
[0004] A problem in connection with temporary signage and barrier arrangements is that it is the conventional practice to provide such barriers and signs in metal for durability. The difficulty with such arrangements it that the parts are heavy to carry and if hit by a car or moving machinery can fly about and cause serious injury. What is required is a barrier which is light, stable, provided with a strong linkage to prevent undesired disassembly, and sufficiently resilient such that blows can be absorbed without disassembly or destruction of the parts.
[0005] In prior art linkages for temporary traffic barriers, post and rail arrangements have been provided with a beaded cord linkage to locate the rail upon a post. After a short while such arrangements tend to disassemble and the beaded cord tends to break if hit and to be readily removed by unauthorised personnel.
[0006] Another type of prior art linkage is the button and slot arrangement wherein a pair of buttons are located in a spaced relation at the end of a hollow extruded rail member, said buttons engaging in elongate slots in the post. The rail is retained in the slot by its own weight. It will be immediately apparent that especially after a little wear the rail maybe inadvertently removed from the post, maybe readily disassembled on being hit by machinery, and is open to ready vandalisation.
[0007] The present invention seeks to provide a cheap and readily utilisable solution to at least some of these problems to provide an improved linkage assembly particularly for traffic sign barriers.
[0008] According therefore to a first aspect of the present invention there is provided a linkage assembly comprising;
a) a first linkage member comprising a first slot,
b) a second linkage member comprising a slot engagement tongue provided with an engagement recess whereby interengagement of the tongue in the slot, and relative movement of the tongue and slot allows engagement of the recess with an edge of the slot to prevent disengagement of the second member while the recess is engaged therein;
characterised in that said slot comprises a first slot section for receiving the tongue, and a second slot section for sliding engagement with said tongue, and in that a locking member comprising a locking tongue is movable relative to said second member to enter said first slot section thereby to retain the recess engaged in the second section of the slot until the locking tongue is withdrawn.
[0009] The first member is preferably a post comprising at least one vertically extending slot, i.e extending along the longitudinal axis of the post. The first linkage member may however comprise a circumferentially, laterally, or vertically extending slot. The first slot section is preferably wider than the tongue, namely the first slot has a lateral extent normal to the plane of sliding engagement between the tongue and the second slot section that is greater than the thickness of the tongue.
[0010] In a particularly preferred form of the invention the locking member is slidable from a released position to an engaged position and wherein the second linkage member and locking member include retaining means to retain said locking member in the engaged position. Said retaining means may be at least one bore or other aperture which when brought into register with the corresponding bore allows a fastening element to be located therein.
[0011] The locking member preferably engages the second member in a predetermined interrelationship so as to be movable into the first slot section.
[0012] It is preferred that the second member is an elongate rail having a generally planar configuration, the tongue being integrally formed in an end section of the rail. In this way the rigidity and stability of the assembled assembly is not comprised by intermediate connection members since the rail is directly connected to the post. The integral nature of the tongue with the rail also clearly has advantages from a manufacturing cost aspect.
[0013] The rail may also comprise a secondary tongue for interengagement with a secondary slot spaced from, and in the plane of said first slot. By this arrangement the rail may extend generally perpendicularly to the axis of the post, although the particular locking configuration allows for a degree of angular alignment without loss of efficacy. In the preferred embodiments, the first slot section is superior to the second slot section.
[0014] The secondary slot engaging tongue may be arranged such that in use it is co-planar with the first engaging tongue, but spaced inferior or superior thereto in use. The secondary slot engaging tongue may be plain in that it comprises no recess, or may be similar to the slot engaging tongue with a recess.
[0015] The engagement recess may extend generally parallel to the slot with which it is to be engaged. It will be appreciated that the height of the slot, i.e its longitudinal extent, approximates to the height of the tongue so that the tongue may readily slide therethrough. The recess may be a generally inverted U-shape, an inverted V-shape, or may be generally rectangular in plan. The contact edges of the tongue may be angular or radiused as desired.
[0016] The locking member preferably engages said second member in a position such that said locking member can be urged to enter the wider first section of the slot in the first member to prevent longitudinal movement of the tongue in the slot.
[0017] Preferably the tongue of the locking member is a planar member and the first section of the slot has a generally rectangular configuration. The second linkage member may be engaged with the locking member by means of a flange engagable in a corresponding slot in the second linkage member. The flange maybe a barbed flange thereby to semi-permanently engage said second linkage member or may be plain so that it may be readily separated therefrom if desired.
[0018] In a particular form of the invention the locking member has a generally elongate shape and is semi-permanently secured to the second member by means of a barbed flange. Remote from the locking tongue the locking member comprises a button adapted to engage in a corresponding bore in the second member when in a locked position. If such a locking member is formed of a resilient material, the locking member may be withdrawn by first pressing the button to disengage it from the bore, and urging the locking member rearwardly away from the first linkage member.
[0019] In a particularly preferred form of the invention the second member and/or the locking member comprises a flange means adapted in use to support a flashing motorway light or similar item, for example a "DORMAN Trafilite". The locking member may be secured to the second linkage member by a tamper proof bolt, or other suitable means. By attaching a motorway light on the second member and/or locking member adjacent a post, the light acts as a damping member which assists to reduce and cancel any undesired oscillations that may be set up in the assembly from, for example wind gusts. Of course, suitable weights may be used in place of the lights so as to act purely as damping means.
[0020] All the elements in accordance to the present invention may be formed of a mouldable plastics material; it is preferred however that all are formed of high density polyethylene although the rails may be formed of PVC if desired.
[0021] In a preferred form of the invention the second linkage member is formed with a radius portion at one edge, for example at least at its intended upper edge and preferably at each intended longitudinal edge. This gives a generally shallow S-shape configuration. The shallow S-shaped configuration of the rail affords it rigidity against bending under, for example, gusts of wind created by passing lorries. The shape of the rail means it will act as an aerofoil improving the aerodynamic characteristics thereof, so as to enhance the rail's stability against wind gusts. The configuration of the rail is moreover such that it is disinclined to distort, for example, warp under hot weather conditions.
[0022] Other profiles which can be used include a reversed L-shape, J-shape, P-shape, I-shape or T-shaped profile. Cylindrical rails can also be used; these may be of generally O-shaped or Q-shaped. In all these arrangements the portion of the second linkage member adjacent the recess maybe cut away so as to allow angular displacement of the first and second members in a vertical sense.
[0023] The locking tongue is preferably closely received in the first slot section of the assembled assembly and is in this regard preferably only marginally wider than the combined width of the tongue and the locking tongue. In this manner, with the second linkage member in position in the first linkage member, lateral relative movement between the first and second linkage members is restricted, thereby increasing the stability of the assembly.
[0024] In a particularly preferred form of the invention the first member is a vertically disposed hollow post provided adjacent its intended upper end with three or four vertically disposed first slots disposed equiangularly about the periphery of said post. Preferably the post has a cylindrical configuration and at least two sets of equiangularly disposed slots at its upper and lower portions.
[0025] In said foregoing arrangement the foot of said post is preferably circular in cross-section and is provided for interengagement with the base, said base comprising a vertically extending bore which is a bare clearance fit for the end of said post, said post end comprising a lug cooperating in a corresponding keyway in said vertically extending bore, said keyway terminating in a circumferentially extending groove to locate the lock and secure the post of the base when relatively rotated.
[0026] The post may alternatively be provided with a bell-ended lower section for engagement with a downwardly facing surface of the base, thereby preventing removal of the righted post from the base, once the post has been inserted. The bell-ended configuration of the base is advantageous in that it presents a particularly rigid and non-collapsible structure, thereby increasing the assembly's stability and resistance to vandalism.
[0027] In a further preferred embodiment, the second member further comprises an information display means, e.g a road sign, having a planar display surface. The information display means may include resilient means disposed, in use, between the post and the display surface so as to restrict relative rotational movement between the display and the post. The resilient means may include two resilient arms adapted to engage the post so as to bias it away therefrom. Alternatively the resilient means may comprise a pair of resilient arms adapted to clamp on opposite sides of the post. In these arrangements, the information display means may be securely and stably locked in position to a post. If a large sign is to be used, it may be provided with two second members as described above, enabling it to be mounted between two adjacent posts.
[0028] According to a second aspect of the present invention there is provided a traffic signage system comprising;
a base including an arcuate aperture; and
a sign including a planar display surface and an arcuate sign support section for insertion in the base aperture so as to connect the sign and the base together.
[0029] Preferably the arcuate aperture is orientated such that its inside curvature faces inwardly of the base. Thus, a sign inserted in the base has an arcuate support section whose outside curvature faces on-coming traffic, when the base is correctly positioned.
[0030] The arcuate nature of the sign support section affords it both strength and resilience. In this connection a flexing area of the sign, i.e that joining the arcuate support section to the display surface, is resilient, but to a lesser degree than the arcuate support section. In the event that a vehicle collides with the sign, the flexing area will relatively readily bend out of shape to avoid damage to the sign and/or to the vehicle, but will, predominately under the resilience of the arcuate sign support section, naturally be returned to its upstanding state once permitted to do so, e.g. once the vehicle has passed. The resilience of the arcuate support section thus acts to pull the sign back into shape. The combined resilience of the flexing area and sign support section is such that it can allow the sign to deform under extreme loads such as during a collision with a vehicle, but not under the everyday forces of e.g. wind gusts.
[0031] Preferably, the base further comprises a central circular aperture for receiving a post. In the preferred embodiments, the base includes a threaded bore connecting the base exterior with the arcuate aperture. A grub screw can then, for example be used to lock the sign in position once it is inserted in the arcuate aperture. Access to the threaded bore is preferably limited, e.g. by a special key, such that the possibility of theft and/or vandalism is limited.
[0033] According to a third aspect of the present invention, there is provided a one-piece moulded sign comprising;
a planar information display surface; and
an arcuate display support for engagement in a correspondingly shaped base aperture, said support being resiliently deformable.
[0034] The invention will now be described by way of illustration only, with reference to the accompanying drawings wherein
Figure 1 shows a vertical elevation from the front of a temporary traffic barrier in accordance to the present invention,
Figure 2 shows a part linkage assembly in plan with the locking member shown in ghost lines,
Figure 3 shows a transverse cross-section through the top area of a post,
Figure 4 shows a side view of locking member,
Figure 4A shows in part vertical section an assembly of the linkage members in the engaged position,
Figure 5 shows a transverse cross-section through a rail in accordance to the present invention,
Figure 6 shows a transverse cross-section through a locking member in accordance to the present invention,
Figure 7 shows a vertical section through a post and base arrangement in accordance to the present invention,
Figure 8 shows a side view of an alternative linkage assembly with a locking member in a secondary position shown in ghost lines,
Figure 9 shows a perspective view of a lower section of a post in accordance with the invention,
Figures 10a, 10b and 10c show views of the linkage assembly when used to support signs,
Figure 11 shows a perspective view of a signage system in accordance with the invention, and
Figures 12a and 12b show alternative signs for use with the system of Figure 11.
[0035] With reference to Figure 1 to 6 of the present invention a post of a generally cylindrical configuration and formed of high density polyethylene is formed so as to locate in a base member (5). The base member (5) is generally circular in cross-section and is weighted to provide a measure of stability to the post located thereby. The interrelation of the post (1) to the base (5) will be described later.
[0036] The post (1) is provided at approximately 90° intervals about its circumferential surface with slots (7) and (8), and with an upper cap (6) adapted to close off the hollow tube.
[0037] The post (1) is adapted for cooperation with an upper rail (2) and a lower rail (3). The upper and lower rails (2 and 3) cooperate with the slots (7) in precisely the same way.
[0038] With reference particularly to Figure 2 a linkage assembly (4) is formed in an end part of a rail (2) shown in planar section (21) in Figure 5, with an upper radius (22) and a lower radius (23) to impart the maximum dimensional stability to the rail. The shallow S-shaped rail is formed of PVC.
[0039] The S-shaped configuration of the rail affords it rigidity against bending under, for example, gusts of wind created by passing lorries. The shape of the rail also acts as an aerofoil improving the aerodynamic characteristics thereof, so as to enhance the rail's stability against wind gusts. The configuration of the rail is moreover such that it is disinclined to distort, for example, warp under hot weather conditions.
[0040] The end (4) of the rail (2) is provided with an upper tongue (9) of a planar configuration. It will be noted that the upper portion of the rail (2) has been removed at (32) to achieve this. The upper tongue (9) has a height which approximates to the height of the slot (7) in the post shown in Figure 3. Similarly lower tongue (10) is adapted to cooperate with the lower vertical slot (8), although in this case the height of the tongue (10) is less than the height of the slot (8). It will be noted that the lower tongue (10) is plain and incorporates no locking means. The upper tongue (9) comprises at its lower portion a recess (11) and below the recess (11), a cutaway portion (12). It will be appreciated that the tongue portion (9) may be introduced into the slot (7). The linkage assembly (4) then may be moved relatively downwardly with respect to the post in Figure 3, thereby locking the recess (11) in the bottom portion (7b) of the upper vertical slot (7).
[0041] As is best shown in Figure 1 the upper portion (7a) of the upper vertical slot has a width approximately double that of the lower portion (7b), said portion (7b) being of a width suitable only to readily locate the tongue (9) and recess (11). It will also be appreciated that the lower tongue (10) can move downwardly in the slot (8) because it has a smaller height than the tongue (9). The upper portion (7a) of the upper vertical slot is preferably coaxial with the lower portion (7b).
[0042] The linkage assembly (4) is also provided with flange slots (13) for interengagement with flanges (14) formed on locking member (17). Locking member (17) has the configuration shown in Figures 2 and 4 and is formed of a resilient PVC material.
[0043] The locking member (17) is provided with a locking tongue (18) complementary bore (19), complementary keyhole bore (20), and on is reverse face (not shown in Figure 4) optionally with a barbed flange (24).
[0044] In the arrangement shown in Figures 1 to 4A with the linkage assembly (4) engaging in the slot (7 and 8) the locking member (17) is introduced toward the wider portion of the upper vertical slot (7a) such that the locking tongue (18) enters the wider portion on either side of the rail (2). When the locking tongue (18) is positioned as shown in Figure 2 it becomes impossible for the recess (11) to disengage from the upper edge of the lower portion of the upper vertical slot (7b) so that the linkage cannot be disassembled.
[0045] As is best seen in Figure 4A, with the locking tongue (18) located in the slot (7a), flanges (14) are located in respective flange slots (13) in the rail (2) thereby causing bores (15) and (19), and (16) and (20), respectively to correspond. A security bolt or tie may be inserted into one or more of these bores to retain the locking member (17) on the linkage assembly (4).
[0046] In this position disassembly of the rail (2) from the post (1) is not possible because the recess (11) cannot become disengaged from the post (1). Further by virtue of the cutaway (12) the rail (2) can swing in the vertical plane upwardly because the rail can pivot to a certain extent about the recess (11), and the lower tongue (10) still cooperates in the lower vertical slot (8) to retain the vertical orientation. Similarly the rail (2) can move downwardly at the end remote from the linkage assembly (4) by virtue of the cutaway portion (12). The width of the upper slot (7a) is only marginally greater than the combined width of the tongue (9) and locking tongue (18) such that there is little or no relative lateral movement available to the tongues once located in the slot. This results in a highly rigid and solid connection.
[0047] In order to disassemble the arrangement it is necessary to release the locking member (17) from the linkage assembly (4) to allow the upper tongue (9) to slide upwardly to release the recess (11) from the lower portion (7b) of the upper vertical slot (7).
[0048] In an alternative arrangement as shown in Figure 6 a barbed flange (24) is provided to the rear face of the locking member (17) of Figure 4. Assembly (4) is also provided with suitable slots in which the barbed flanges (24) can cooperate. It is then only necessary to interengage the locking member (17) of Figure 6 with the linkage assembly (4) of rail (2) for example, and to slide the locking member such that the tongue (18) engages with the upper vertical slot portion (7). By also providing bores (19 or 20) the arrangement can be locked in position in the usual way.
[0049] Flanges (14) also extend outwardly of the plane of the locking member (17). This allows a flashing motorway light, for example, to be located on flanges (14) shown in Figure 4 and be bolted for example through keyway bore (20) both to secure the flashing motorway light to the assembly and to lock the tongue (18) in position.
[0050] By attaching a motorway light on the rail adjacent a post, the light acts as a damping member which assists to reduce and cancel any undesired oscillations that may be set up in the assembly from for example, wind gusts. Of course the rail may be suitably weighted to achieve the same damping effect.
[0051] In an alternative embodiment shown in Figure 8 the locking member (27), which corresponds to locking member (17), has been somewhat simplified by the provision single flange slot (28) adapted for cooperation with a barbed flange secured to the reverse face of the locking member (27) as shown in Figure 8. Positioned rearwardly of slot (28) is an aperture (29) to form a locking bore. The locking member (27) is also formed with a tongue portion (18) at its forward end and with a locking button (30) at its other end. It will be appreciated that if the locking member (27) is urged leftwardly as shown in ghost lines in Figure 8, the button (30) will engage with the bore (29) and because the member (27) is formed of a resilient PVC planar material, the button (30) will engage in the bore (29) until pressed outwardly while locking member (17) is urged rearwardly.
[0052] Also shown in Figure 8 is an arrangement wherein the lower tongue member (10) has been dispensed with, although in other respects the assembly is generally similar.
[0053] In the arrangement of Figure 7 there is provided a base (5) of a moulded plastics material provided with a bore (26) which is a sliding clearance fit for the exterior periphery of a post (1). Toward the lower end of the post (1) there is provided at least one lug extending radially outwardly from the post. The end of the lug may be located in a lug channel (26) whereupon the post may be driven into interengagement with the base (5) until the lug reaches the bottom of the vertical bore (26). The vertical bore (26) may extend circumferentially at that point, whereby a relative rotation of the post relative to the base (5) locks the post into engagement with the base. Since in use post (1) in accordance to the present invention is interengaged with rail members (2) and (3) and since rotation of the base (5) is difficult in situ, it becomes difficult to separate the base (5) from the post (1) until a full disassembly has occurred.
[0054] Since the post (1) rails (2) and (3) and base (5) are all formed of a resilient plastics material such as HDPE, and since the locking assembly makes it difficult for the rails and post to separate, barriers in accordance to the present invention are particular resistant to sideways thrusts since they are strong, resilient and do not disassemble on impact. However, the plastics portions are light enough such that if hit by a car at speed, for example, they may separate but will do little damage.
[0055] The rails in accordance with Figure 5 are particularly preferred because if left flat and run over by heavy earth moving equipment on soft ground they may well not shatter or break.
[0056] The arrangements in accordance to the present invention are particular suited to temporary traffic barriers, barriers for exhibitions and shows, and barriers for incidental small works, but the linkage itself is of wider applicability for use for other purposes than temporary motorway barriers and signs.
[0057] It is also possible to use the rails 2 and 3 to support motorway signage such as speed limits, hazard warnings etc. These may be locked on to the linkage assembly (4) by means of suitable clips or bolts etc in the usual way.
[0058] As shown in Figure 9, the post (1) may alternatively be provided with a bell-ended lower section (35) for engagement with a downwardly facing surface of the base, thereby preventing removal of the righted post from the base, once the post has been inserted. The bell-ended configuration of the base is advantageous in that it presents a particularly rigid and non-collapsible structure, thereby increasing the assembly's stability and resistance to vandalism.
[0059] Figures 10a and 10b show partially cut-away views of preferred embodiments wherein the post (1) directly supports a sign (36). In combination with the locking tongue and slot arrangement of previous embodiments, there is provided in the arrangement of Figure 10a a spring support means comprising two flexible arms (37) which are biased inwardly so as to engage and clamp on to opposite sides of the post to securely lock the sign in position.
[0060] In the arrangement of Figure 10b, the arms (38) are arranged to engage the post so as to bias the sign away therefrom as it is moved into engagement with the post. Figure 10c shows a plan view from above of the arrangement of Figure 10b. As illustrated, the arms (38) deform backwardly from a rest position to a loaded position, indicated in ghost lines, as the tongue or tongues provided on the sign are moved forward as indicated by the arrow into and latched in the slot or slots provided on the post (1).
[0061] With both arrangements, the flexible arms have a function in clamping the sign to the post to thereby increase its stability and inhibit its rotational movement on the post.
[0062] In the arrangement of Figures 10b and 10c, the rail provided on the sign includes recessed tongues (39) which engage edges of the slots (40) in the post. A locking tongue (41) is shown provided on the upper tongue but may be provided on either.
[0063] If a particularly large sign is used, it may be provided with two sets of tongues and support springs so that it can be supported between two posts.
[0064] The base may itself be configured to support signs directly as shown in Figure 11. A base (42) includes a central hole (43) suitable for accepting a post as in previous embodiments, and also an arcuate aperture (44). The arcuate aperture is adapted to accept the support section (45) of sign (46), alternatives of which are shown in Figures 12a and 12b. The shape and size of such signs may be varied to suit requirements. The signs include a planar display surface (47) and an arcuate support section (45). The signs are one-piece moulded from, for example polyethylene making them relatively inexpensive.
[0065] The arcuate configuration of the sign support section affords the sign a rigidity which prevents it being blown over under, for example, gusts of wind from any direction. A flexing area (48) of the sign joining the sign display surface to the sign support section is also resilient but to a lesser degree than the arcuate support section. If a vehicle collides with the sign, the flexing area can deform to allow the sign to bend backwardly out of the way without causing damage to the vehicle and without the sign itself being damaged. The flexing area may in this connection be provided as corrugations in the moulded sign. The sign may moreover include moulded strengthening webs or have reinforcing members inserted to enhance its performance at specific areas.
[0066] The resilience of the sign support section will act to right any deflection of the sign from its moulded shape. The sign will thus return to its moulded shape, with the sign display surface upright once the deflecting force is no longer present. The arcuate nature of the support section moreover inhibits bending of the sign over its front. As shown, the base includes a threaded bore (49) which can be accessed using a special key to releasably lock a grub screw in position through aperture (50) in the sign. The bore may be provided so as to connect with the centre of the arcuate aperture in the base, as shown in Figure 11 or at any suitable position in the base. For example, the bore may connect with the arcuate aperture at its edges so as to engage in suitable cut-out portions (51) in the sign support section, as indicated by the ghost lines in Figure 11. By virtue of such key and grub screw arrangements, the sign is less likely to be stolen and vandalised. Of course any suitable mechanism may be employed to lock the sign in position to the base, for example, the sign support section may include an outwardly biased resilient flap having a rib which can engage a recess in the base.
1. A linkage assembly comprising
a) a first linkage member comprising a first slot
b) a second linkage member comprising a slot engagement tongue provided with an engagement recess whereby interengagement or the tongue in the slot and relative movement of tongue and the slot allows engagement of the recess with an edge of the slot to prevent disengagement of the second member while the recess is engaged therein;
characterised in that said slot comprises a first slot section for receiving the tongue, and a second slot section for sliding interengagement with said tongue, and in that a locking member comprising a locking tongue is movable in relation to said second member to enter said first slot section thereby to retain the recess engaged in the second section of the slot until the locking tongue is withdrawn.2. A linkage assembly according to claim 1 wherein the first member is a post comprising
at least one slot extending along the longitudinal axis of the post.
3. A linkage assembly according to claim 1 or 2 wherein said first slot section has a
lateral extent greater than a thickness of the tongue.
4. A linkage assembly according to any preceding claim wherein the locking member is
slidable from a released position to an engaged position, and wherein the second linkage
member and the locking member include retaining means to reversibly retain said locking
member in the engaged position.
5. A linkage assembly according to any preceding claim wherein the second member is an
elongate rail having a generally planar configuration, the tongue being integrally
formed in an end section of the rail.
6. A linkage assembly according to claim 5 wherein said rail comprises a secondary tongue
for interengagement in a secondary slot spaced from said first slot.
7. A linkage assembly according to claim 5 or 6 wherein the rail is provided with a radius
portion at least at its intended upper edge.
8. A linkage assembly according to claim 5, 6 or 7 wherein a cutaway portion is provided
adjacent the end of the rail extending from or near said recess to allow for angular
displacement in the plane of the rail.
9. A linkage assembly according to any preceding claim, wherein the locking tongue is
closely received in the first slot section of the assembled assembly.
10. A linkage assembly according to any of Claims 2 to 9 wherein the intended lower end
of the post is substantially circular in cross-section and wherein a base is provided
for cooperation therewith, said base comprising a vertically extending bore which
is a bare clearance fit for said post end, the post end comprising a lug cooperating
in a corresponding keyway in said vertically extending bore, said keyway terminating
in a circumferentially extending groove to locate said lug and secure the post to
the base when relatively rotated or wherein the post has a bell-ended lower section
for engagement with a downwardly facing surface of the base.
11. A linkage assembly according to any preceding claim further comprising an information
display means including a planar display surface.
12. A linkage assembly according to claim 11, wherein the information display means includes
resilient means adapted to engage the post to restrict relative rotational movement
between the information display means and the post.
13. A traffic signage system comprising;
a base including an arcuate aperture; and
a sign including a planar display surface and an arcuate sign support section for insertion in the base aperture so as to connect the sign and the base together.
a base including an arcuate aperture; and
a sign including a planar display surface and an arcuate sign support section for insertion in the base aperture so as to connect the sign and the base together.