Post and rail assembly

A post and rail assembly comprising a rail having one end of a flexible tether secured thereto, and a post provided with an aperture through which the flexible tether can be passed. The other end of the tether is provided with an enlarged head which in at least one orientation with respect to the aperture is incapable of passing therethrough. A locking element is releasably engageable with the post to restrict the aperture and prevent both passage of the enlarged head therethrough and removal of the end of the tether therefrom.

The present invention relates to post and rail assemblies. 
Road traffic and road works barriers are known in which horizontal rails 
are suspended by tethers at their ends between upright posts. British 
Patent Specification No. 1531724 describes one known arrangement in which 
rails are suspended on loops hooked onto upright posts, and British Patent 
Specification No. 1531725 describes a second known arrangement in which 
rails are suspended on ropes the ends of which support enlarged heads 
received in keyhole slots in upright posts. These known arrangements have 
proved successful as they provide a simple means for erecting a temporary 
barrier, a wide variety of barrier shapes can be constructed given that 
the relative positioning of the upright posts is not critical, and the 
effect of side winds on the barrier is reduced given that the rails can 
move to a limited extent relative to the upright posts. 
Unfortunately although the known arrangements do enable a barrier to be 
erected very easily, they can also be dismantled very easily. This makes 
them particuarly vulnerable to unauthorised tampering. 
British Patent Specification No. 2147986 describes a road traffic lamp unit 
supporting system comprising a lamp unit having an integral battery 
compartment which is inserted into a tubular upright support, and a simple 
locking mechanism which prevents removal of the lamp unit from the support 
unless an appropriate key is inserted into the support. The use of this 
arrangement has proved successful in limiting the frequency with which 
lamp units are removed by unauthorised persons. 
It is an object of the present invention to provide a post and rail 
assembly in which a rail can be secured by a tether to a post in such a 
way as to discourage unauthorised tampering therewith to disconnect the 
rail from the post. 
According to the present invention, there is provided a post and rail 
assembly comprising a rail having one end of a flexible tether secured 
thereto, a post provided with an aperture through which the flexible 
tether can be passed, the other end of the tether being provided with an 
enlarged head which in at least one orientation with respect to the 
aperture is incapable of passing therethrough, and a locking element 
releasably engagable with the post to restrict the aperture and prevent 
both passage of the enlarged head therethrough and removal of the end of 
the tether therefrom. 
Preferably, the post is provided with a second aperture through which the 
enlarged head can be passed before the tether is passed through the first 
aforesaid aperture and the locking means is engaged with the post. 
Preferably also, the first aperture comprises a slot which is open at one 
end to permit the tether to be passed therethrough but not the enlarged 
head. 
Preferably, the locking element comprises an abutment means engageable with 
a second resiliently biased abutment means mounted on the post. 
Preferably, the locking element can be disengaged from the post by means of 
a key.

With reference to FIG. 1, an assembly suitable for use as a road traffic 
barrier comprises a rail 1 having one end of a flexible tether 2 secured 
thereto, a post 3 in the form of a cone with an enlarged base 4, and a 
locking element 5 for the tether 2 adapted to form part of a road hazard 
warning system such as a lamp 6 for mounting on top of the post 3. It is 
usual to mount warning systems such as lamps or reflectors on the top of 
the posts forming part of road traffic barriers. It is therefore envisaged 
that the locking element 5, which forms a part of the present invention, 
will be able to fulfil the dual function of locking the warning system 5 
and of securing the tether to the post 3. It is not a requirement of the 
invention, however, that this be the case. 
The post 3, as shown in FIG. 1, is preferably tubular and may, for example, 
be a tubular plastics upright, the base 4 of which may be a container 
closable by a removable plug or cover so that liquid ballast or 
particulate or friable solid ballast can be introduced therein. At its 
upper end, the post 3 has a substantially cylindrical portion 7 to which 
the rail 1 is attached by means of the tether 2, as will be described 
below, and which co-operates with the locking element 5. 
Referring now to FIGS. 2 to 4 which show a first embodiment of post and 
rail assembly, the rail 1 has one end of a flexible tether 2, such as a 
rope, attached thereto and the free end of the tether 2 is provided with 
an enlarged head, in the form of a toggle 8. The upper cylindrical portion 
7 of the post 3 is provided with a pair of apertures 9 and 10. The 
apertures 9 comprises a circular hole of dimensions sufficiently large to 
permit the passage of the toggle 8 therethrough. The aperture 10, however, 
is in the shape of an inverted keyhole and is open at the top to provide a 
slot in the rim 11 of the post 3. The toggle 8 cannot pass through the 
aperture 10 but the tether 2 being of reduced dimensions can be threaded 
into the aperture 10 downwardly from the rim 11 of the post 3. 
In order to attach the rail 1 to the post 3, the toggle 8 is firstly passed 
through the aperture 9 into the interior of the post 3, as indicated in 
FIG. 2. The toggle 8 is then pulled out of the top of the post 3 and the 
attached tether 2 slotted into the aperture 10, the toggle 8 then abuts 
the rim 11 of the aperture 10 on the exterior of the post 3. The rail 1 is 
hence supported by the tether 2 which is attached to the post 3 and can be 
releasably locked thereto by the locking element 5. As shown in FIG. 4, 
the element 5 is designed to locate in the interior of the cylindrical 
portion 7 of the post. The actual locking mechanism employed to secure the 
element 5 to the post 3 is described below with reference to FIG. 8. 
However, it wil be appreciated that the element 5 forms a cap which closes 
the open end of the post 3 around the rim 11. It is, therefore, not 
possible to unfasten the tether 2 from the post 3 as the aperture 10 has 
been restricted by the element 5 closing the open end thereof and the 
toggle 8 is unable to pass through the aperture 10. The only way of 
disengaging the rail 1 from the post 3 when the locking element 5 is in 
position is to sever the tether 2. To discourage this, the tether 2 is 
preferably made from a tough plastics material. 
FIG. 5 shows a second embodiment of the invention wherein the upper 
cylindrical portion 7 of the post 3 is provided with only a single 
aperture 12. As before, the flexible tether 2 is secured to the rail 1 and 
has a free end with an enlarged head in the form of a toggle 8. However, 
in this embodiment, the toggle 8 has a substantially rectangular end 
portion 13 and the aperture 12 is of a similar shape so that in one 
orientation, the toggle 8 can be passed through the aperture 12 into the 
interior of the post 3 but when then rotated through 90.degree. cannot be 
withdrawn therefrom. 
As in the first embodiment, once the rail 1 has been attached to the post 
3, the locking element 5 same and thereby lock the toggle 8 in position by 
restricting the aperture 12. As shown in FIG. 7, in this embodiment the 
locking element 5 is preferably provided with a depending lug 14 which 
covers the upper portion of the aperture 12 and reduces its size such that 
the toggle 8 cannot then pass through in any orientation with respect to 
the aperture 12. 
The third embodiment of post and rail assembly shown in FIG. 6 is similar 
to the second embodiment can be located in the open end of the post 3 to 
cap described above with reference to FIG. 5. However, in this embodiment 
the upper cylindrical portion 7 of the post 3 is provided with a slot 15 
which is open at its upper end in the rim 11 of the post 3. The flexible 
tether 2 is attached to the rail 1, as before, but the toggle 8 does not 
have a special shape, as in the second embodiment described above, but is 
of a size which is incapable of passing through the slot 15. 
In order to attach the rail 1 to the post 3, the tether 2 adjacent the 
toggle 8 is threaded into the slot 15 so that the toggle 8 holds the 
tether 2 by abutment against the edge of the slot 15 on the interior of 
the post 3. A locking element similar to as previously described with 
reference to FIG. 7 can then be located in the post 3 to lock the toggle 8 
in position. A depending lug provided on the element covers the top 
portion of the slot 15 to prevent removal of the tether 2 therefrom. 
Referring not to FIG. 8, one means of engaging the locking element 5 to the 
post 3 will now be described. The locking element 5 of FIG. 8 includes an 
upstanding portion 5a to which for example a lamp (not shown) may be 
secured. Engageable abutment means 16 are provided on the lower portion of 
the element 5 and on the interior of the post 3. Secured to the interior 
of a recess 17 formed in the interior wall surface of the post 3 is a 
metal strip 18. The strip 18 is bent and secured to the post 3 at one end 
only so that it forms a leaf spring depending downwardly into the post 3 
and is resiliently biased towards the interior of the post 3. Engageable 
with the spring 18 is an abutment means in the form of a pair of outwardly 
projecting clips 19 located side by side on the lower edge of the element 
5. The clips 19 are formed in the shape of an arrow head so that they each 
have a flat surface 20 extending outwardly from the element 5 at an acute 
angle which terminates with a second flat surface 21 projecting 
substantially normally from the adjacent surface of the element 5. As 
shown in FIG. 8, when the element 5 is pushed downwardly into the post 3, 
the surfaces 20 of the clips 19 bear against the spring 18 and displace it 
to allow location of the element 5 in the post 3. However, once the 
surfaces 20 are pushed past the lower edge 22 of the spring 18, the latter 
springs resiliently back to its former position. In this position, the 
lower edge 22 of the spring 18 is located above the surfaces 21 of the 
clips 19, which thereby prevent the element 5 from being withdrawn from 
the post 3. 
Once the element 5 is located in position in the post 3, the recess 17 
defines, with the adjacent surface of the element 5, a pocket at the base 
of which is located the abutment means 16. In order to disengage the 
element 5 from post 3 a key 23, as shown in FIG. 8, must be used. The 
pocket, therefore, protects the locking arrangement but allows access 
thereto for the key 23. Additionally, a channel 24 may be formed in the 
exterior surface of the element 5 adjacent the recess 17. The channel 24 
runs between the clips 19 and is designed to assist in the correct 
location of the key 23 in the pocket. 
The key 23 comprises a flexible plastics strip formed with the handle 25 at 
one end of a slender shank 26 and a wedge-shaped head 27 at the other end. 
The width of the head 27 is designed so that it can slide within the 
channel 24. However, the depth of the head 27 is designed to be greater 
than the combined depth of the surfaces 21 of the clips 19 and the depth 
of the channel 24. 
To disengage the element 5 from the post 3, the head of the key 23 is 
inserted into the channel 24 and pushed downwardly into the pocket. The 
wedge-shaped head 27, being of greater dimensions than the chips 19, as 
described above, acts on the spring 18 so that the lower edge 22 of the 
spring 18 is biased away from the adapter 3 and eventually clear of the 
edge of the surfaces 21. When this occurs, the element 5 can then be 
lifted out of the post 3 along with the key 23. 
In an alternative arrangement, the abutment means 16 could be arranged to 
be accessed by the key 23 through the hole or aperture formed in the 
cylindrical part 2 of the post 3. 
Hence, it will be appreciated that the post and rail assembly of the 
present invention provides a means of creating, for example, a road 
traffic barrier which is easy to set up and substantially vandal proof. 
Additionally, the provision of a locking element disengageable from the 
post 3 by means of a key allows the assembly to be set up and taken down 
easily, when required. Although the examples described above have only 
related to the attachment of a single rail to a post, in practice, most 
posts would be provided with the means to support at least two rails so 
that a long barrier could be made up.