The invention relates to safety equipment for use with scaffolding that is erected to create working platforms (known as “lifts”) against the side of buildings under construction or repair. Health and safety regulations specify that each such lift alongside such a building is provided with bottom boards to create a working platform for the builders working at that level, and a top rail, intermediate rail and bottom kick board on the side of the working platform remote from the building. Those are regulations intended to create a safe working area for the builders working on the working platform. If the building or repair work involves loose masonry, then to protect those on the ground below there must be a mesh guard extending from the top rail to the working platform, or at least extending down below the top of the bottom kick board, to prevent debris falling from the working platform. Those mesh guards are commonly referred to as brick guards, although clearly their purpose is to prevent all dangerous debris, not simply bricks, falling from the working platform.
Conventional brick guards consist of a metal wire mesh to which is welded a pair of metal hooks for hooking over the top rail of the lift. Such brick guards have a very short working life and can themselves create a significant working hazard for those working on the scaffolding. The welds joining the hanging hooks to the metal mesh frequently fracture when (as often happens) they are struck by a falling piece of masonry. The guard then leans inwardly at an angle from the remaining hanging hook and obstructs the working platform. Moreover it no longer adequately protects those working below. It is not uncommon for both hooks to become detached, in which case the wire mesh guard can fall, to lie completely across the working platform, creating a trip hazard. It is even known for such falling or fallen brick guards to slip through a gap between adjacent bottom boards or between the bottom boards and the kick boards, so as to fall to the ground below. Therefore the currently used 1brick guards, which are specified with the intention of increasing site safety, can in fact create their own safety hazard.
GB-A-2534034, GB-A-2379241, GB-A-2385372 and AU-A-2006100471 are representative of prior proposals for different designs of brick guards. Those prior proposals have in common the fact that they each comprise a rectangular mesh screen with integral hooks along the top edge for hooking over a scaffolding lift top rail, and that the preferred, or in most cases only, material contemplated for the mesh screen and integral hooks is metal, welded into a wire mesh to form the screen or bent into a hook formation to form the hooks. Problems are encountered when the brick guards are detached from the scaffolding and stacked together for storage or transportation between building sites. There is a great tendency for the hooks of one brick guard to become entangled in the mesh of others, and GB-A-2354034 and GB-A-2379241 address this problem by specifying that the hooked portions must be of width greater than the mesh size of the screen portion, so as to avoid such entanglement. That solution does not, however cure the problem that the brick guards can get very rough usage on a building site, so that often the wire from which the hooks are formed will break, which simply creates the problem of potential entanglement but to a greater degree because each broken end of a fractured hook can potentially form a hook to become entangled with the mesh of other brick guards during storage and transportation.
EP-A-1072736 discloses an alternative design of brick guard in which the mesh may be polypropylene and carries along its bottom edge a toe guard or bottom kick board. The mesh and bottom kick board may be made in one piece or may be made separately, for example of different materials (for example polypropylene and metal) and bolted together. Similarly the hooks from which the mesh is suspended may be made separately and bolted onto the mesh as a permanent union. When such a brick guard is detached from the top rail of the scaffolding lift, however, many of the advantages of the (optional) polypropylene mesh are lost. The weight of the bottom kick board, which is permanently attached to the mesh screen, more than counteracts the light weight of the polypropylene mesh screen, so that each individual brick guard can be quite heavy to handle. Moreover the weight is unevenly distributed and is concentrated along the bottom edge of the brick guard. The detached brick guards, complete with their attached hooks, tend to become distorted and bent, and have a potentially very short working life.
It is an object of the invention to provide a brick guard which avoids the above disadvantages.
The invention provides a brick guard being a piece of safety equipment for use with scaffolding, having the characteristics of claim 1 herein.
It is the releasable nature of the retaining action by which the hook members are clipped to the top edge runner portion of the mesh screen which gives the brick guard of the invention its novelty and unique advantages as compared with prior proposed brick guards. To remove the brick guard of the invention from a top rail of a scaffolding lift, the mesh screen is first unclipped from the hook members after which it can be stored completely flat. Then the hook members can be lifted off the top rail and collected, for example in a bag or sack. The essentially planar elements of the brick guards, namely the mesh screens, are collected and stored separately from the essentially three-dimensional elements, namely the hook members; and the separation of those elements during storage and transportation has a profound benefit for the user. The mesh screens take up far less space during storage and transportation, and their working life is improved immeasurably. When re-used they are far more likely to maintain the flat planar shape which they had when new, which increases the safety of the product in a working environment as well as improving the appearance of the scaffolding lift, giving a more competent and professional appearance when the product is used.
To achieve a simple, secure and easily releasable mechanism for clipping the hook members to the top edge runner portion of the mesh screen, each hook member preferably comprises at least one pair of mutually spaced cooperating retaining members one of which encircles a lower half of the top edge runner and the other of which encircles the upper half. When the top edge runner adopts its natural and undeformed straight linear configuration it is bounded completely by those cooperating retaining members, although at mutually spaced locations. If the top edge runner is flexed from its natural and undeformed straight linear configuration it can be lifted out of contact with one of the pair of retaining members, and then dropped away from the other. It may thus be readily unclipped from the hook member. The semi-rigid plastics material from which the mesh screen is made contributes significantly to this ease of unclipping the hook members.
Moreover the material from which the screen is made, being semi-rigid plastics material, incorporates sufficient resilience that if the brick guard is hung from a scaffolding top rail and then subjected to the impact of falling bricks, it will deflect resiliently, throwing the falling bricks or other masonry back onto the bottom boards of the scaffolding lift, thus avoiding fracture. Another time when conventional brick guards become damaged is when dismantling the scaffolding. Although not recommended practice, it is commonplace for builders to unhook the brick guards and throw them or drop them to the ground below. Conventional metal brick guards can bend and distort on impact with the ground, but the brick guards of the invention tend to retain the flat profile of the mesh screen even after falling from considerable heights, partly due to the semi-rigid nature of the plastics material but mainly because the mesh screens are wholly planar after being unclipped from the hook members. A particular suitable plastics material is polypropylene, which has a high impact resistance. The brick guard of the invention is suitably formed by injection moulding, with the screen being integrally moulded in a single injection moulding process. The hook members, similarly, may each be integrally moulded in a single injection moulding process. When the brick guard is injection moulded, the intersecting rails and bars of the mesh screen can be formed with a profile that presents low wind resistance. A higher strength is provided by moulding the rails and bars of the mesh screen in a single plane, with the four internal angles at each intersection being radiussed. A small portion of the mesh screen may be filled in to create a solid plate for advertising purposes, without increasing the wind resistance unduly. The top edge runner forms a continuous moulded top edge to the mesh screen and may be the top rail of the mesh with the same size and rigidity as the remainder of the mesh or an increased size and rigidity. One particular advantage of injection moulding the mesh screen is that the brick guard can be designed to become highly visible from above and below. That is an advantageous additional safety feature, because a crane operator working at a height well above that of the scaffolding lift, or a foreman on the ground below giving directions to such a crane driver, can see the brick guards very clearly indeed. If there is an access point along the length of the scaffolding lift where there is no brick guard because materials are intended to be delivered and off-loaded onto the scaffolding lift at that access point, then that becomes a very highly visible access point. The visibility can be further enhanced by moulding the brick guard from a plastics material that is self-coloured in a highly visible, possibly fluorescent, colour.
Injection moulding is not, however, the only way of constructing a brick guard according to the invention. The mesh screen could be cut and formed from a sheet of plastics material, provided the sheet thickness was sufficient to create a semi-rigid mesh screen; or the mesh screen could be created by extruding the horizontal and vertical elements of the mesh screen at an extrusion temperature such that the horizontal and vertical elements of the mesh screen coalesce and become integrally bonded with each other where they cross.
The brick guards of the invention can be made of any convenient length or of a range of different lengths so that they can be placed end to end completely to fill a working lift of a run of scaffolding. The height, however, is preferably constant, being the standard height between the bottom board and the top rail of the scaffolding lift.
Referring first to
The mesh screen 2 of
Each hook member 3 comprises four integrally moulded retaining members 10, 11, 12 and 13. They are formed in a row, the two on the outside (10 and 13) encircling in use the upper half of the top runner portion 5 of the mesh screen 2 and the two on the inside (11 and 12) encircling in use the lower half of the top runner portion 5. Each adjacent pair, 10 and 11 or 12 and 13, thus forms a pair of mutually spaced cooperating retaining members which together completely encircle the top runner portion. To attach the mesh screen 2 to the hook members 3, all that is necessary is to deflect the top runner portion 5 away from its natural linear configuration as shown in
To remove the brick guard from the top rail of the scaffolding lift, all that is necessary is to insert a forefinger or thumb below the portion of the top runner portion 5 of the mesh screen 2 between the retaining members 11 and 12, and to bend it upwards and inwards, away from the hooked member 3. Each hooked member 3 then readily unclips from the mesh screen 2 and the screen can be removed, flat and unencumbered by laterally protruding hooked hangers. The hooked members 3 can then themselves be removed individually from the top rail and collected in a bag or sack.
Number | Date | Country | Kind |
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0716857.8 | Aug 2007 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB2008/002048 | 6/16/2008 | WO | 00 | 5/11/2010 |