"Improvements Relating to Support Platforms" Support platforms are commonly needed where heavy equipment is to be loaded on to the roof of a building. The objective of having such a platform is to provide a level area on which the equipment can be mounted and to spread the load evenly over the area of the roof surface. Normally it is often necessary to install structural load-bearing members initially at roof level. This can involve cutting through a weatherproof membrane of the roof into the roof structure and building concrete plinths on structurally sound points. The weatherproof membrane then has to be restored. Finally a steel support structure may be built onto the tops of the plinths.

It is an object of this invention to provide a freestanding support platform for this purpose that can readily be assembled from individual parts carried to the installation area, or which can be preassembled and craned into position.

Accordingly, this invention provides a support platform comprising an array of tiles set in rows and constituting a base, flooring units located side by side in multiples extending along each row of tiles, and flange channel support members extending across the lines of flooring units and secured thereto, the tiles having upwardly projecting protrusions which locate within respective flooring units such that drainage gaps are formed between each row of tiles.

Such a platform can readily be assembled from the individual parts, namely the tiles, the flooring units and the support members. These three items essentially create a grillage construction with each layer of the platform being set at right angles to the next. The tiles (ideally formed from a resilient material such as re-cycled PVC) can absorb local surface imperfections and thus assist

in spreading the load on the platform evenly. This removes the need to alter the roof surface to provide support plinths to accept the platform in order to spread the load. Additionally, the tiles add weight for overturning stability. The drainage gaps allow for run off of surface water to minimise the risk of"ponding"occurring on a roof surface. Ideally tiles will be secured to the flooring units in such a way that drainage gaps are formed additionally between the tiles along each row thereof. This allows for drainage in the other direction.

In the preferred arrangement the flooring units have a top surface preformed as a grating to provide a gripping surface. Preferably the flooring units are provided in side by side sets of 3 along each row of tiles.

Ideally, the upper support members are interconnected to one another by bracing cross-members, to create a torsion box.

It is preferred that the main wall of each flange channel support member should have holes formed therein. These holes will also act as lifting points enabling a lifting mechanism to be attached to a support member. They can also reduce the weight of the support member (but without essentially reducing its strength). The holes would provide passageways for cables or the like.

Ideally, height adjustable locating studs will project from the tops of the support members, onto which cabinets or the like can be secured. These enable equipment mounted (directly or indirectly) onto the locating studs to be levelled.

The invention may be performed in various ways and a preferred example thereof will now be described, with reference to the accompanying diagrammatic

drawings, in which: Figure 1 is a plan view of part of a support platform of this invention; Figure 2 is an end view of the platform shown in Figure 1; Figures 3 and 4 are plan and side views respectively of a tile forming part of the platform of Figure 1; Figure 5 is a vertical section on line A-A; Figure 6 is a vertical section on line B-B; and Figure 7 has a vertical section similar to that of Figure 6 illustrating an extension unit spliced on.

The support platform illustrated in the drawings is constructed from three main components. The first of these is an array of tiles 1, each of which carries 2 rows of 3 projecting protrusions 2. As can be seen from Figures 2 and 6 these protrusions provide location for the lower flanges 3 of flooring units 4, which comprise the second component of the platform. Each set of three extending flooring units 4 (located on the array of tiles 1) is linked together by support members 5, which extend in length across the whole width of the support platform and thus link together and spread the equipment load over each set of three flooring units 4. Bracing struts 6 and 7 interconnect pairs of support members 5, to create a wide shallow box for the distribution of longitudinal torsion.

As can be seen from Figure 5 the top surface of each flooring unit 4 is preformed as a grating at 8 to provide a secure grip for persons walking over the platform. The flooring units 4 are secured to the tiles 1 by means of screws 21 whose heads locate in the grating 8 through a bespoke insert and which are

fixed into the thicker section of the tiles where the protrusions 2 are formed.

Figure 5 also shows the cross sectional shape of the support members 5, which are secured by bolts 9 to the grating 8. Each bolt 9 carries a half nut 9A within the grating thickness to make the bolt captive whilst still accessible from underneath. Bolts 10 are also provided to secure the bracing cross members 6.

Where required, alternative studs 11 extend upwardly and enable levelling to be performed. Support channel members 12 carried by these studs provide the final mounting support for equipment (such as cabinets) 13. The adjustable studs 11 provide a levelling system for the equipment 13. As can be seen from Figure 2 the main wall of each flanged support member 5 may optionally incorporate a number of holes 14. These not only reduce the weight of the channel members 5, but also provide locations for attachment of lifting apparatus and passageways through which cables can be passed between various bits of equipment.

It will be noted from Figure 6 that the lower flanges 3 of the flooring units 4, locating against protrusions 2 of adjacent tiles 1, ensure that a small gap 15 is formed between these tiles. Furthermore, as can be seen from Figure 5, the fixing of the flooring units 4 along their length to the rows of tiles 1 is such that further gaps 16 are formed between the tiles in the other direction. These gaps allow for the movement of roof surface water. The tiles 1 themselves are constructed from re-cycled PVC and form a relatively soft blanket contact with the roof surface. This enables them to absorb local surface imperfections and assist in even spreading of the load on the platform. The platform itself spreads the load of any equipment mounted on it over the entire surface area of the

platform by virtue of the fixing of each of the three layers of the platform at right angles to the next.

An extension can be formed to one side of the platform shown in Figure 1 by adding a further set of three flooring units 4 (or more), as illustrated in Figure 7. This extra set of flooring units (with associated tiles 1 and support members 5) is linked to the main platform by means of splice plates 17 and 18 bolted to the flanges of the adjacent support members 5.

The support members 5 are pre-drilled in the two flanges 19 and 20 (to enable assemblies to be constructed in various mounting positions using bracing members 6 and 7 of suitable lengths to provide support for a range of different items of equipment).