This invention relates to a beam of the kind comprising a pair of elongate members providing spaced webs which are maintained in spaced parallel relation by an intermediate member which extends between the webs and which contributes to the resistance of the beam to buckling of the webs under loading of the beam, such a beam hereinafter being referred to as a beam of the kind specified. A plurality of such beams may be used in the horizontal plane as a support for horizontal shuttering or a plurality of such beams may be used in the vertical plane as a support for vertical shuttering, ie as soldiers.

A beam comprising a pair of spaced parallel webs and a plurality of intermediate spacing members is disclosed in G-B-A-2071177 wherein each intermediate member comprises a hollow member engaged with inwardly facing abutments on the respective webs. The webs and the hollow members are formed as aluminium extrusions.

It is an object of the present invention to provide an improved beam of the kind specified.

In accordance with the invention there is provided a beam of the kind specified wherein each of the webs is provided with spaced apart abutments extending substantially over its entire length, each abutment on the one web facing a corresponding abutment on the other web, and wherein the intermediate member comprises a pair of spaced apart spacers and a clamping element; each

spacer being engaged at two opposed edges thereof with a one of said abutments on one web and a facing one of said abutments on the other web; the clamping element being operable to bias the spacers away from one another and into clamping engagement with the respective abutments on the webs.

The said edges of the spacers and the respective abutments are conveniently complementarily shaped for engagement with one another.

The clamping element preferably comprises a screw threaded member extending through an internally threaded aperture on one of said spacers into engagement with a blind hole in the other said spacer whereby, upon rotation of the threaded member,- tensile loading is applied via the spacers and the abutments to those parts of the webs intermediate said abutments.

Each web may be provided with flanges at each end thereof, each flange projecting from a respective web in a direction away from the other web. The corresponding facing abutments may be disposed intermediate the ends of the webs or, alternatively, such corresponding facing abutments be disposed at the ends of the webs.

The webs and their abutments are conveniently formed as aluminium extrusions and, where so provided, such extrusions may also include said flanges and further flanges on each web.

Oτher features of the invention will become apparent from the following description given herein solely by way of example with reference to the accompanying drawings wherein:

Figure 1 is a diagrammatic cross-sectional view through a beam according to the invention and being of the type adapted to receive a timber batten for supporting horizontal shuttering.

Figure 2 is a diagrammatic cross-sectional view of a similar beam to that of Figure 1 but wherein the • spacers are located adjacent the ends of the webs.

Figure 3 is a diagrammatic cross-sectional view through an end part of the beam of either Figure 1 or Figure 2 showing a splicing member for securing adjacent beams together in axial relationship and

Figure 4 is a diagrammatic cross-sectional view through a beam in accordance with the invention but being formed of a heavier section material . throughout and adapted to be used as a vertical soldier.

Referring to Figure 1 of the drawings the beam comprises two elongate members 10 and 12 each consisting of an extruded aluminium section having a respective web 14 and 16 and two spaced apart parallel abutment flanges 18, 20 and 22, 24 intermediate the ends of the webs and extending over substantially the full length of the respective web. Each web 14, 16 also includes respective end flanges 26, 28 and 50, 52 defining planar parallel outer end faces to each web. The beam is assembled by- means of a plurality of sets of pairs of spacer plates 34 and 36 with an associated connecting bolt 38, opposed edges of each plate being shaped for complementary engagement with the shaped ends of opposing abutments.

As shown in Figure 1 , one of the plates 36 (the lower plate) is provided with an internally threaded aperture and the other plate 34 (the upper plate) is provided with a central blind hole. A screw threaded bolt 38 extends through the threaded aperture into engagement with the blind hole so that, upon rotation of the bolt, the two spacer plates 34 and 36 are biased away from one another into engagement with their respective abutments 18, 22 and 20, 24 on the webs to apply tensile loading to those parts of the webs intermediate the abutments.

As will be clearly seen from Figure 1 , the upper faces of the abutments 18 and 22 are planar whereby a timber batten 40 may be supported upon a pair of facing abutments on the two webs to receive horizontal shuttering nailed thereto when a plurality of such beams are used in the horizontal plane for the purpose of supporting shuttering.

Thus the plurality of sets of pairs of spacer plates 34, 36 and connecting bolts 38 permit the two elongate members 10 and 12 to be spaced apart and to join the webs thereof in such a manner that they are mutually- supportive.

Those end flanges 26, 32 of the webs which project from a respective web in a direction away from the other web, together with those further end flanges 28, 30 which project from a respective web in a direction towards the other web, are shaped to accommodate attachment means such as clamps or the like. However, said further flanges are also adapted to accommodate splicing members for the securing together of two adjacent beams in axial relationship. Such a splicing member 42 is shown in

Figure 3 of the drawings and comprises a central web element outwardly flanged on both sides thereof at each of its ends with said flanges being profiled to enable the splicing member to be telescopically receivable in adjacent ends of two adjacent beams for connecting them together.

As shown in Figure 2 of the drawings,. wherein like reference numerals refer to like parts hereinbefore described, the said further end flanges 28, 30 comprise the abutments for clamping engagement by the respective spacer plates 34 and 36. In this embodiment, an extended screw threaded bolt 38 extends through the threaded aperture in the plate 36 to engage in the blind hole in plate 34 whereby, upon rotation of the bolt, the two spacer plates 34 and 36 are biased away from one another into engagement with the respective pairs of abutments 28, 30 on the webs to apply tensile loading to the web ^' s over substantially their full depths between their ends.

It will be appreciated, in either of the embodiments of Figures 1 or 3, that the beam, in use, may be subjected to co pressive loading which compression, which may tend to buckle the webs outwardly from one another, is relieved by the tensile loading pre-applied to the webs by the bolt 38 and spacer plates 34, 36.

A further beam according to the invention is shown in Figure 4 of the drawings wherein the webs flanges and abutments of the elongate members together with the sets of pairs of spacer plates and connecting bolts are substantially the same as hereinbefore described with reference to Figure 1 and wherein like reference numerals refer to like parts hereinbefore described. However, the beam illustrated in Figure 3 is intended for use as a

soldier, ie as a vertical support beam for shuttering. In such an embodiment the extruded sections together with the spacer plates are manufactured of heavier section material and, in application as a soldier, there is no need for provision of a timber batten.