GB2496453A - Barrier reinforcement - Google Patents

Abstract

A reinforcement member for a barrier structure (2 Fig 1) such as a gate comprises at least a first fixed post 4 and a second fixed post 6, a barrier (8 Fig 1) extending between the two posts and a reinforcement member comprising at least one extensible element 22 having a substantially uniform load bearing capacity along its length connected to the two fixed posts 4. The extensible element may be a rope. Also claimed is a barrier structure with a barrier extending between two posts and a extensible element reinforcement member connected to both posts. The reinforcement may comprise four extensible restraints that are covered with a sheath or covering to suspend it from the gate. The reinforcement may be attached to the post via a shaft 28 passing through eyelets in each restraint. The reinforcement is designed to absorbed or dissipate sudden impacts that such barrier structures may encounter, e.g. car crash.

Description

BARRIER REINFORCEMENT

The present invention relates to a reinforcement, having particular, but not exclusive application, to barrier structures such as gates. The reinforcement has particular utility in absorbing or dissipating sudden impacts that such barrier structures may encounter.

It is known to provide a barrier structure such as a gate or other structure to prevent access past a point, for example to bar passage onto a driveway. However, many such barrier structures are little more than obstructions that provide a deterrent effect and do not, and are not intended to, provide an impact resistant barrier for example in the event that a vehicle should crash, either accidentally or deliberately, into the barrier structure. In failing to resist such impacts, such barriers are often destroyed with the result that debris is created and scattered by the force of the impact. Such flying debris will be understood to present its own dangers.

In some circumstances, a barrier structure having mass can be provided to withstand such an impact. However, this can lead to problems in moving and securing the barrier if the barrier structure is intended on occasion to allow access.

Further, retro-fitting a mass to an existing movable barrier may prevent the movable barrier from operating as intended.

Thus, there is a requirement for a simple reinforcement that may be provided integrally with a barrier structure, or retrofitted thereto, to allow a barrier structure to deal with impact forces such as those resulting from a vehicle impact. It is an advantage of the present invention that it provides a solution to this problem.

According to a first aspect of the present invention, a reinforcement for a barrier structure comprises at least one extensible element having a substantially uniform load bearing capacity along its length.

Preferably the or each extensible element is adapted to extend 5%-35% before failure.

Preferably the or each extensible element is a rope or other fibrous element.

Preferably the or each extensible element has a substantially uniform load bearing capacity of between 50 and 150 tonnes, more preferably between 90 and 150 tonnes.

According to a second aspect of the invention a barrier structure comprising at least a first fixed post and a second fixed post, a barrier extending between the first post and the second post, a reinforcement comprising at least one extensible element having a substantially uniform load bearing capacity along its length connected at a first end to the first fixed post and connected at a second end to the second fixed post.

Preferably the barrier is a displaceable barrier extruding between the first post and the second post in a closed position and the reinforcement is releasably connected at the second end to the second fixed post.

Preferably the or each extensible element is adapted to extend 5%-35% before failure.

Preferably the or each extensible element is a rope.

Preferably the or each extensible element has a load bearing capacity of between 50 and tonnes, more preferably between 90 and 150 tonnes.

Preferably the displaceable barrier comprises a gate extending between the first fixed post and the second fixed post and is releasably securable to the second fixed post.

More preferably, the gate comprises at least one leaf.

Preferably the or each extensible element inclUdes an eyelet at the second end into which is received a displaceable member.

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a front view of a bi-fold gate incorporating a reinforcement according to the present invention; Figure 2 shows an end view along arrow A of Figure 1.

Figure 3 shows a rear view of the gate of Figure 1; Figure 4 shows an end view along arrow B of Figure 3; Figure 5 shows a plan view of a detail of the structure of the gate and the reinforcement; Figure 6 shows a part sectional view through one end of an extensible restraint; and Figure 7 shows a plan view of one end of an extensible restraint Referring first to Figures 1 to 4, a bifold gate illustrates by way of example a displaceable barrier structure 2. The structure and operation of the bifold gate will be described in outline as these will be known to one skilled in the art. The gate is shown in a closed position in Figures 1 to 4. In Figure 5, the reinforcement is shown in bold with the gate in an open position (the gate is shown in ghost) and in ghost with the gate in the closed position.

The barrier structure 2 includes a first post 4, here the gate post, and a second post 6, here the leaf post. The first post 4 and second post 6 are securely located in position. The barrier structure 2 includes a bifold gate 8 extending between the first post 4 and the second post 6.

In the illustrated embodiment, the bifold gate 8 comprises a post hung element 10, fixed at a first end for pivoting movement with respect to the first post 4, and a leaf hung element 12 mounted for pivoting movement on a free end of the post hung element 10, for example on hinges 14. A free end of the leaf hung element 12 is releasably secured to the second post 6, for example by way of a suitable locking system. The post hung element 10 is driven with respect to the first post 4, for example by a suitable drive assembly.

When the leaf hung element 12 is released from the second post 6, driving of the post hung element 10 draws the leaf hung element 12 towards the first post 4. Reversing the drive to the post hung element 10 will push the leaf hung element 12 back towards the second post 6.

As may be seen by reference to Figure 5, the post hung element 10 may be driven about a pivot or hinge mechanism 18 spaced from and secured to a rear of the first post 4.

A first end of a reinforcement 20 may also be secured to this pivot or hinge mechanism 18.

A second end of the reinforcement 20 is releasably secured to the second post 6.

In the illustrated embodiment, the reinforcement 20 comprises four extensible restraints 22, each restraint 22 extending from the first post 4 to the second post 6. The reinforcement 20 is conveniently further provided with a sheath or covering 24 by which the reinforcement 20 may be suspended from the gate 8, while maintaining relative movement between the reinforcement 20 and the gate 8.

In an alternative embodiment (not shown), the or each restraint 22 could be supported individually from the gate. In either case, as will be apparent, relative movement of each restraint 22 with respect to the gate 8 is retained.

It is useful to support the or each restraint 22 relative to the gate 8 so that the restraints 22 do not fall away and drag as the gate 8 is opened, but retains their height relative to the gate 8.

It is further useful to support the second end of at least one of the second ends of the restraints 22 on the gate adjacent the second post 6 in order to allow the second ends of the restraints 22 to be releasably secured to the second post. Preferably all of the second ends are supported, for example secured in this way. Any of the second end(s) not so supported may be supported by second end(s) so supported.

Each end of each restraint 22 is conveniently provided with an eyelet 30 through which it may be secured to either the first post 4 or the second post 6 as required.

In the illustrated embodiment, a retractable shaft 28 (Fig 7) secured to the second post 6 is received through the eyelets 30 at the second end(s) of the restraints. When the gate is to be opened the shaft 28 is retracted. Actuation of the shaft may occur before, during or shortly after the gate is released from the second post. When the gate is returned to the closed position, the shaft 28 is returned through the eyelets 30 of the restraints 22 to secure the reinforcement 20 in position.

In an alternative embodiment, not shown, the gate is secured to the second post by the reinforcement alone.

In the illustrated embodiment, the restraint(s) 22 take the form of ropes of a predetermined length, the ends of which are woven back in on themselves to provide the eyelets 30. The eyelets 30 may be further provided with an internal bush 32, to aid in rotation of the eyelet about an axis and an external cover 34 extending around a portion of the eyelet 30. The restraint(s) 22 do not move with respect to the bush 30, it is the bush 30 that rotates about the axis.

Preferably the bush 30 and cover 34 are connected by a base 36 and a cap 38, for example to prevent the ingress of dirt.

The bush 30, cover 32. base 36 and cap 38 may be formed of any suitable material, for example nylon or other synthetics material. The cover 32 is conveniently removable with respect to the base 36 and cap 38.

The rope may be of any suitable material, preferably of plastics material, more preferably of nylon or other synthetics material such as of high modulus polyethylene (HMPE) fibre (for example that sold under the brand name PLASMA by Puget Sound Rope).

A rope having a load bearing capacity of between 50 and 150 tonnes, preferably between 90 and 150 tonnes is suitable. A typical bifold gate has a span of 4.2 meters between the fisrt and second posts. A nylon rope having a minimum tensile strength of 951.9 kN extending between 30 and 35% at its break point is suggested for a 4.2 meter bi-fold gate.

The kinetic energy of a moving vehicle can be considered to be E= 1/2mv2 where E=Energy of vehicle (J) M=mass of vehicle (kg) and v=velocity of vehicle (mis) Thus for a 7.5 tonne vehicle travelling at 40 mph (17.89 mis) E is l200kJ, and at 50mph (22.35 m/s) E is 1873kJ.

The energy absorbed by an extensible element having a substantially uniform load bearing capacity along its length can be considered to be P=1/2kx2 where P=Energy stored (J) k=spring constant of extensible element (Nim) -that is the force required to generate a 1 m extension and x= extension of extensible element.

The maximum force acting on the reinforcement occurs when the vehicle is arrested, that is has zero velocity. The force acting on the barrier (and the associated reinforcement) at this time is F = kx.

Thus, for the nylon rope considered above, with a minimum tensile strength of 951.9 kN, the force required to extend the rope by 25% is 793kN. At 25% extension, a 4.8 lope 5 extended by 1.2 m, such that the stored energy is 476kJ.

It can be seen that foul 4.8 lengths of such rope, extended by 25%, (well within the bleak point) will absorb 1904kJ, that is all the kinetic energy of a 7.5 tonne vehicle travelling at 40mph (or even at 50 mph).

Accordingly, it will be understood that one skilled in the art may engineer the reinforcement in line with the risk of a particular impact and that in some cases the reinforcement 20 may comprise a more or less than four restraints 22, for example a single restraint 22. Also, it will be understood that the reinforcement may comprise one or more extensible restraints of a first material for example nylon rope and one or more extensible restraints of a second material for example an HMPE lope to meet the requirements of the anticipated impact forces.

It is a further advantage of the patent invention that the reinforcement acts to prevent the dispersion of debris following damage to the barrier as a result of the impact. Accordingly, multiple restraints achieve this advantage more efficiently than a few restraints or one restraint.

Further, the use of the sheath or covering 24 further catches or otherwise impedes the dispersal of debris resulting from the impact with the barrier structure.

Suitable nylon ropes for use in the present invention may, for example, be obtained from Puget Sound Rope.

Alternatively a HMPE rope having a minimum tensile strength of 400 kN extending between 5%-8% at its break point may be used. Such ropes are available under the mark PLASMA from Puget Sound Rope.

It will be understood that the reinforcement may be applied to a variety of displaceable barriers, including for example, sliding gates. The reinforcement may also be applied to increase the effectiveness of fixed barriers including those intended to withstand impacts.

For example, the reinforcement may be fitted to a traffic barrier, both to provide an additional mechanism to absorb energy on impact, but also to assist in the prevention or reduction of debris resuiting from any damage caused to the barrier on and following impact. The reinforcement in such a case may be a single rope of relatively larger diameter. The reinforcement may extend along several posts of a traffic barrier, though being secured at each end to first and second posts forming a part of the traffic barrier.

Claims (1)

1. <claim-text>CLAIMS1 A reinforcement for a barrier structure comprising at least one extensible element having a substantially uniform load bearing capacity along its length.</claim-text> <claim-text>2 A reinforcement according to claim 1, in which the or each extensible element is adapted to extend 5%-35% before failure.</claim-text> <claim-text>3 A reinforcement according to claim 1 or claim 2 in which, the or each extensible element is a rope.</claim-text> <claim-text>4 A reinforcement according to any previous claim, in which the or each extensible element has a load bearing capacity of between 80 and 150 tonnes, more preferably between 90 and 150 tonnes.</claim-text> <claim-text>A barrier structure comprising at least a first fixed post and a second fixed post, a barrier extending between the first post and the second post, a reinforcement comprising at least one extensible element having a substantially uniform load bearing capacity along its length connected at a first end to the first fixed post and connected at a second end to the second fixed post.</claim-text> <claim-text>6 A barrier structure according to claim 5, in which the barrier is a displaceable barrier extruding between the first post and the second post in a closed position and the reinforcement is releasably connected at the second end to the second fixed post 7 A barrier structure according to claim 5 or claim 6, in which the or each extensible element is adapted to extend 5%-35% before failure.8 A barrier structure according to any of claims 5 to 7, in which the or each extensible element is a rope.9 A barrier structure according to any of claims 5 to 8, in which the or each extensible element has a load bearing capacity of between 80 and 150 tonnes, more preferably between 90 and 150 tonnes.A barrier structure according to any of claims 5 to 9, in which the displaceable barrier comprises a gate extending between the first fixed post and the second fixed post and is releasably securable to the second fixed post.11 A barrier structure according to any of claim 10, in which the gate comprises at least one leaf.12 A barrier structure according to any of claims 5 to 11, in which the or each extensible element includes an eyelet at the second end into which is received a displaceable member.13 A reinfoicement substantially as described herein with reference to the accompanying drawings.14 A barrier structure substantially as described herein with reference to the accompanying drawings.</claim-text>