Description: This invention relates to scaffold clamps suitable for use a part of a scaffolding system. In particular, but without limitation, this invention relates to scaffold clamps comprising spacer wings having carefully selected dimensions that permit the mutually orthogonal connection of scaffold tubes in a tube-on-tube and/or in a clamp-on-clamp configuration. The invention may facilitate bracing a scaffold assembly to a wall using the same transom tubes that are used to support scaffold boards. A further possible advantage of the invention is the ability for form a "birds nest" intersection of vertical and horizontal scaffold tubes in a tube-on-tube configuration.

Scaffolding is a system of tubes, connectors, boards, ladders and other items that can be connected together to form a framework around, for example, a building. Scaffolding can be used in various ways, such as: to provide elevated walkways around and/or external access to, a building, for example so that workers can make repairs to, or construct, the building; a (or part of) temporary and/or free-standing construction, for example to support display screens at live events; and to provide temporary structural support to a building during remedial works. The applications of scaffolding are not limited to the foregoing examples, which are merely exemplary.

One of the main advantages of scaffolding is its modularity, which enables the scaffold to be highly customised and adapted to particular situations using a relatively small number of different building units. For example, scaffold tubes can be used vertically to provide support for other scaffold tubes arranged horizontally, which can be topped by boards forming walkways. The same tubes can be used to form guardrails, cantilevered platforms, and mountings for derricks and so on. Similarly, scaffold boards can be used as parts of walkways, toe boards, walls, etc.. It will be appreciated that the range of configurations is almost limitless. When erecting a scaffold, due care and attention needs to be paid to safety and structural integrity. Health and Safety regulators often mandate the use of approved scaffold schemes, and before a scaffold can be used on site, it usually needs to be checked, signed-off and certified ("scaff- tagged") by an approved Health and Safety professional. It will be appreciated that during erection and disassembly of a scaffold, the scaffold is not certified, and so the likelihood of an accident occurring is greatest during these times.

Two of the main causes of scaffolding-related accidents involve: accidentally releasing scaffold components that then fall, thus posing a hazard to bystanders and/or the structural integrity of the remaining scaffold; and misalignment of structural scaffold tubes. Many scaffolding accidents occur because the scaffold needs to be adapted to suit particular applications and/or where different types of scaffolding components (e.g. from different manufacturers or systems) are used together.

The main consideration, from a structural point of view, is ensuring that scaffold tubes are correctly aligned, both relative to the horizontal and vertical, as well as relative to one another. Vertical scaffold tubes need to be plumb to ensure that weight is correctly transmitted through them and to minimise bowing or buckling that can occur in non-vertical tubes. Likewise, horizontal tubes need to be level to ensure that walkways, guard rails etc. are not canted. Where a scaffold is assembled from a single set of like components, these requirements can usually be met quite easily.

For example, it is known to interconnect scaffold tubes using scaffold clamps, which comprise a pair of interconnected C-shaped claws that engage with respective scaffold tubes, and a corresponding set of clamp portions that clamp each of the scaffold tubes firmly into their respective claws. Scaffold clamps of this general type are very well-known and do need further explanation here. Where a scaffold is assembled using only one type of scaffold clamp, in all likelihood, the spacings between adjacent or overlapping tubes will be the same, thus ensuring that sets of scaffold tubes can be correctly aligned, that is to say, the horizontal tubes will lie in one plane, and the vertical tubes will lie in another plane. However, in certain situations, for example in the case of walkways, it is often more convenient, rather than building a walkways from scratch from tubes and boards, to employ ladder beams and transom units, which can be hung from and/or connected to horizontal scaffolding tubes. These ladder beams, however, are generally located in a different plane to their supporting scaffold tubes, and so the addition of further tubes to the ladder beams can result in the further tubes being offset relative to the planes of other tubes. Thus, the only way to interconnect these further tubes with the remaining scaffold is to incline them slightly, which is often contraindicated.

Then, when there are plumb and level tubes alongside inclined tubes, it can be difficult to work out quickly, by visual inspection, which clamps support which tubes, and so when disassembling the scaffold (usually not in the reverse order in which it was assembled), there is a chance of an incorrect clamp being undone, which can result in a component of the scaffold falling off.

This invention aims to provide a solution to one or more of the above problems and/or to provide an improved/alternative scaffold clamp.

Various aspects of the invention are set forth in the appended claims.

According to one aspect of the invention, there is provided a scaffold clamp comprising first and second generally claw portions, and a respective set of releasable clamping portions associated with each of the claw portions for securing, in use, a respective scaffold tube between the claw portion and its respective clamp portion, wherein the scaffold clamp further comprises a spacer interposed between the generally claw portions.

Another aspect of the invention provides a scaffold assembly comprising pair of scaffold tubes interconnected by a scaffold clamp as described herein.

Suitably, the scaffold assembly comprises at least one vertical scaffold tube connected to at least one first horizontal scaffold tube, the first horizontal scaffold tube forming one part of a ladder beam, and wherein a second horizontal scaffold tube forming another part of the ladder beam is affixed to the vertical scaffold tube by clamp, wherein the spacer of the scaffold clamp is dimensioned to bring the first and second horizontal scaffold tubed into vertical alignment. Suitably, the scaffold assembly comprises a second horizontal scaffold tube affixed to the vertical scaffold tube by a clamping portion forming part of a transom unit. Suitably, the scaffold assembly may comprise a further vertical scaffold tube affixed to the ladder beam by way of a scaffold clamp as described herein. Suitably, the dimensions of the spacer of the scaffold clamp are selected to bring the vertical scaffold tube and the further vertical scaffold tube into alignment.

Another aspect of the invention provides a scaffold clamp substantially as hereinbefore described, with reference to, and as illustrated in, Figures 4 to 8 of the accompanying drawings.

Another aspect of the invention provides a scaffold assembly substantially as hereinbefore described, with reference to, and as illustrated in, Figures 4 to 9 of the accompanying drawings.

Suitably, the claw portions are generally C-shaped, i.e. adapted to accept/receive a scaffold tube.

The provision of a spacer interposed between the claw portions means that the centres of the generally C-shaped claw portions (and thus, in use, the centres of the connected scaffold tubes) can be/are maintained at a desired spacing. Suitably, the desired spacing is different to that of a standard scaffold clamp. Suitably, the desired spacing is greater than that of a standard scaffold clamp, i.e. a known scaffold clamp that may be used on another part of a scaffold assembly comprising scaffold clamps in accordance with the invention.

Suitably, the spacer, comprises a (generally cuboidal) projection formed integrally with each of the claw portions. The projections can be permanently connected, for example, by welding, to one another to form the spacer between the inner surfaces of the claw portions to maintain them in a fixed, spaced-apart configuration. Alternatively, the projection can be integrally formed with just one of the claw portions, and can be permanently connected, for example, by welding, to the claw portion of the other part of the connector.

In certain applications, use of the scaffold clamp of the invention usefully enables scaffold tubes to be connected between scaffold systems of different types: the spacer avoiding the need for further scaffold tubes or components to be inclined or offset where the planes of the components of the different scaffolding systems are not coplanar.

In one embodiment, the spacer is fixed, and provides a rigid connection between the claw portions of the scaffold clamp.

The claw portions can be arranged about the spacer in the same orientation (i.e. to interconnect a pair of parallel scaffold tubes); at right angles (i.e. to interconnect a pair of perpendicular scaffold tubes); or at any desired angle, such as 45-degrees, 30-degrees, 60-degrees etc.

In another embodiment, the spacer comprises a swivel, which provides a rotatable connection between the claw portions of the scaffold clamp. Such a configuration may be useful to connect scaffold tubes at irregular angles to one another and/or so that a single type of scaffold clamp in accordance with the invention can be used in a wider range of situations. The swivel, where provided, may be lockable at a desired relative claw orientation, for example, using a spline shaft or grub screw.

Suitably, the dimensions of the spacer are selected to ensure that interconnected tubes from different scaffolding systems are coplanar or parallel. In a preferred embodiment of the invention the spacer is configured to provide a substantially 38mm (i.e. 38mm +/- 0.5mm, +/- 1mm, +/- 1.5mm, +/- 2mm, or +/- manufacturing tolerances) spacing between the outer diameters of overlapping; or in one specific embodiment, a substantially 86.3mm spacing between the centres of overlapping 48.3mm OD scaffold tubes. The aforementioned dimensions render the scaffold clamp of the invention ideally suited for use with scaffold assemblies incorporating eadylok or readylock-type prefabricated transom units.

The scaffold clamp is suitably manufactured from strong, tough, durable materials, such steel, galvanised steel and stainless steel.

Suitably, the claw portions and their respective releasable clamping portions are together shaped and dimensioned to receive, in use, standardised scaffold tubes, such as 48.3mm OD scaffold tubes. The releasable clamping portions are suitably detachably and/or releasable affixed to the claw portions by releasable locking means, such as by bolts and nuts, a cam lock device or similar.

Suitably, the scaffold clamp conforms to EN74 (and/or any of its variants). In other words, the scaffold clamp is suitably sufficiently load-bearing to enable it to conform to EN74, that is to say, having sufficient resistance to slippage, bending moments and cruciform loading to conform to the structural (strength, gripping and flexure) requirements of, for example, EN74-1 (2005).

Preferred embodiments of the invention shall now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 3 is a side view of a known scaffold assembly comprising a vertical scaffold tube supporting a ladder beam using a known scaffold clamp and a transom unit: the ladder beam being inclined due to the lateral offset of its upper and lower horizontal tubes;

Figure 1 is a schematic plan view corresponding to Figure 3 showing the lateral offset that would occur if the ladder beam of Figure 3 were not inclined;

Figure 2 is a schematic representation of Figure 1 in which the components have been drawn side-by-side, rather than atop one another for clarity;

Figure 6 is a side view of a scaffold assembly comprising a vertical scaffold tube supporting a ladder beam using an embodiment of a scaffold clamp in accordance with the invention: the ladder beam now being plumb;

Figure 4 is a schematic plan view corresponding to Figure 6 showing the alignment of the upper and lower horizontal tubes of the ladder beam;

Figure 5 is a schematic representation of Figure 4 in which the components have been drawn side-by-side, rather than atop one another for clarity;

Figure 7 is a plan view of the scaffold clamp of the invention as shown in Figures 4, 5 and 6;

Figure 8 is a side view of the scaffold clamp of the invention as shown in Figures 4, 5 and 6; Figure 9 is a schematic perspective view (not to scale) of a scaffold assembly in accordance with an aspect of the invention; Figure 10 is a perspective view of another embodiment of a scaffold clamp in accordance with the invention;

Figure 11 is a side view of two scaffold clamps as shown in Figure 10 in a "check fitting" configuration;

Figure 12 is a perspective view of two scaffold clamps, as shown in Figure 10, affixed in a clamp-on-clamp, tube-on-tube configuration, to a vertical scaffold tube;

Figures 13 and 14 are, respectively, plan and side views of the clamps shown in Figure 12 used to interconnect three scaffold tubes in a mutually orthogonal relationship;

Figures 15 to 18 are left- and right-hand views, a plan view from below and a perspective view, respectively of a scaffold assembly utilising scaffold clamps in accordance with the invention.

Referring now to Figures 1, 2 and 3, a known scaffold assembly 10 comprises a vertical scaffold tube 12 connected to the lower horizontal tube 14 of a ladder beam 16 by way of a known scaffold clamp 18. The ladder beam 16 comprises an upper horizontal tube 20, which runs parallel to the lower horizontal tube 14, and the two 14, 20 are interconnected at intervals by struts 22.

The upper horizontal tube 20 of the ladder beam 16 engages with a clamping part 24 of a transom unit 25. The clamping part 24 is formed from a sheet of steel bent into a generally M-shape when viewed from above (as in Figure 2), the limbs 28 of which comprise C-shaped cut outs when viewed from the side (as in Figure 3) for receiving the upper horizontal tube 20 of the ladder beam 16, and the interconnecting part 30 abuts the vertical scaffold tube 12. A clamp portion 32 firmly grips the vertical tube 12 to the interconnecting part 30 of the clamping part 24 to form a rigid connection.

The transom unit 25 comprises a horizontal tube 26 that is oriented perpendicular to the ladder beam 16, which horizontal tube 26 supports a floor surface (not shown) of a walkway.

As can be seen from Figures 1, 2 and 3, the C-shaped cut out of the clamping part 24 of the transom unit 25 causes the upper horizontal tube 20 of the ladder beam 16 to be inwardly offset relative to the lower tube 14 of the ladder beam 16, thus causing the ladder beam 16 to be inclined relative to the vertical. Even modest inclinations can significantly affect the structural characteristic of the ladder beam. Further, if a further vertical scaffold tube (not shown) were to be dropped from the upper horizontal tube 20 of the ladder beam 16, it is readily apparent that this further vertical scaffold tube (not shown) would be inwardly offset relative to the aforementioned vertical scaffold tube 12.

Structurally, this is significant because it would not then be possible to extend the further vertical scaffold tube (not shown) upwards and build upon it, or to use it as a structural component of the scaffold assembly 10 because it would be out of alignment with the remaining vertical scaffold tubes 12, and so forces could not be transmitted directly from one vertical scaffold tube to another. Therefore, in the event of an obstruction located above the vertical scaffold tube 12, existing scaffolding assemblies 10 do not readily permit extending upwards around the obstruction by affixing further vertical scaffold tubes to, say, a cantilevered ladder beam 16 and building upwards from that.

Turning now to Figures 4, 5 and 6 of the drawings, the solution is to use a scaffold clamp 50 in accordance with the invention, such as that shown in Figures 7 and 8 of the drawings. Referring to Figures 7 and 8 of the drawings for the time being, the scaffold clamp 50 in accordance with the invention comprises a pair of generally C-shaped claw portions 52 that engage with the outer diameter of a scaffold tube 12, 14, 20, 26 of a certain size range and a pair of releasable clamping portions 54. The releasable clamping portions 54 are pivotally connected to the claw portions 52 via a pintle 55 enabling the camping portions 54 to be flipped open to accept a scaffold tube 12, 14, 20, 26 into the claws 52. Once inserted, the clamping portions 54 can be pivoted into engagement, and a bolt and nut arrangement 57 cooperating between the claw 52 and clamping portions 45 firmly and rigidly grips the scaffold tube 12, 14, 20, 26 in position, thus inhibiting or preventing relative movement of the scaffold tube 12, 14, 20, 26 and scaffold clamp 50 thereafter, until released.

As previously mentioned, the scaffold clamp 50 of the invention further comprises a spacer 56, which, in the illustrated embodiments, is permanently welded between the inner surfaces of the C-shaped claw portions 52 to maintain them in a fixed, spaced-apart configuration. In the illustrated embodiment, the spacer 56 separates 59 the inner surfaces of the C-shaped claw portions 52 by 18mm, such that the outer diameters of the scaffold tubes 12, 14 are 38mm apart 61 (or their centres are 86.3mm apart 63). In the illustrated embodiment, the 38mm dimension 61 corresponds to the lateral offset 40 of the upper 20 and lower 14 horizontal tubes of the ladder beam 16 previously described.

It will be appreciated that: the aforementioned dimensions could be changed/adapted to suit different requirements; and/or that the rigid, welded spacer of the illustrated embodiments could be replaced by a suitably dimensioned swivel unit (not shown).

Thus, when the scaffold clamp 50 of the invention is now applied in place of the known scaffold clamp 18 to the scaffold assembly 10 previously described, the lateral offset 40 of the lower 14 horizontal tube of the ladder beam 16 is removed. This is shown in Figures 4, 5 and 6 of the drawings.

Referring now to Figures 4, 5 and 6 of the drawings, the scaffold clamp 50 in accordance with the invention is now used to connect the lower horizontal tube 14 of the ladder beam 16 to the vertical scaffold tube 12, and the spacer 56 now compensates for the offset of the transom unit 25 relative to the vertical scaffold tube 12. In Figure 6 in particular, it can now be seen that the ladder beam 16 is aligned vertically such that its rungs 22 are now parallel to the vertical scaffold tube 12.

This has several advantages including: improved structural integrity compared with the configuration of Figures 1, 2 and 3; and the ladder beam 16 now being used within design specifications/parameters. Most significantly, however, the scaffold clamps 50 of the invention enable the scaffold assembly 100 to be extended upwardly off the ladder beam 16 using further vertical scaffold tubes, provided such further vertical scaffold tubes (not shown) are connected to the upper 20 or lower 14 horizontal tubes of the ladder beam 16 using scaffold clamps 50 in accordance with the invention. In such a situation, the further vertical scaffold tubes (not shown) would be outwardly offset relative to the ladder beam (by virtue of the spacer 56) thus bringing them in-line (i.e. coplanar) with the existing vertical scaffold tubes 12. Turning to Figure 9 of the drawings, a scaffold assembly 100 in accordance with an aspect of the invention comprises three vertical scaffold tubes 12 connected to a horizontal scaffold tube 156 using known scaffold clamps 18. A horizontal ladder beam 16 is connected to two of the vertical scaffold tubes 12 using scaffold clamps 50 in accordance with the invention, this providing a lateral offset 40 between the plane 150 of the vertical scaffold tubes 12 and the plane 154 of the ladder beam 16.

A walkway surface 251 is supported on a pair of transom units 25 as previously described, which connects to the ladder beam 16 via couplings 28 previously described.

One of the vertical scaffold tubes 12' extends upwardly to a level above the walkway 251 and is connected to another horizontal scaffold tube 156 using known scaffold clamps 18. Thus, the two horizontal scaffold tubes 156 lie in in the same plane 152.

The scaffold assembly 100 is extended laterally by supporting further vertical scaffold tubes 120 off a cantilevered portion of the ladder beam 16, using scaffold clamps 50 in accordance with the invention. The spacers 56 of the scaffold clamps 50 of the invention compensate for the offset 40 between the plane 154 of the ladder beam 16 and the plane 150 of the vertical scaffold tubes 12. Thus, the further vertical scaffold tubes 120 are coplanar 150 with the remaining vertical scaffold tubes 12, 12'.

This configuration permits the further scaffold tubes 120 to be coupled to the other vertical scaffold tubes using horizontal scaffold tubes 156 and known scaffold clamps 18. Thus, the scaffold assembly 100 in accordance with the invention enables all of the horizontal scaffold tubes 156 to share a common plane 152 and all of the vertical scaffold tubes 12, 120 to share a common plane 150 also. This greatly facilitates assembly and disassembly of the scaffold 100; provides improved structural integrity, and maintains the correct "lines" of the scaffold assembly 100 thus meeting certain mandated Health and Safety requirements.

Referring now to Figures 10 to 18 of the drawings, another embodiment of a scaffold clamp in accordance with the invention is substantially as previously described, save for a few modifications as described hereinbelow. Identical reference signs have been used to identify identical features to those described previously, merely to avoid repetition herein.

In Figures 10 to 18, the scaffold clamp 500 comprises a pair of claw portions 52 each comprising a part-cylindrical concavity 502 that engages, in use (but not shown in Figure 10) with the outer diameter of a scaffold tube (not shown); and a pair of releasable clamping portions 54.

The releasable clamping portions 54 are pivotally connected to the claw portions 52 via a pintle 55 enabling the camping portions 54 to be flipped open to accept a scaffold tube into the claws 52. Once inserted, the clamping portions 54 can be pivoted into engagement, and a bolt and nut arrangement 57 cooperating between the claw 52 and clamping portions 54 firmly and rigidly grips the scaffold tube in position, thus inhibiting or preventing relative movement of the scaffold tube and scaffold clamp 500 thereafter, until released.

As previously mentioned, the scaffold clamp 500 of the invention further comprises a spacer 56, which, in the embodiments illustrated in Figures 10 to 18 of the drawings, comprises a generally cuboidal projection 504 formed integrally with each of the claw portions 52: the cuboidal projections 504 being permanently welded 506 to one another to form the spacer 56 between the inner surfaces of the claw portions 52 to maintain them in a fixed, spaced-apart configuration.

As described previously, the spacer 56 separates the inner surfaces of the claw portions 52 by 18mm, such that the outer diameters of the scaffold tubes are 38mm apart (or their centres are 86.3mm apart). In the illustrated embodiment, the 38mm dimension corresponds to the lateral offset 40 of the upper 20 and lower 14 horizontal tubes of the ladder beam 16 previously described.

It will be appreciated that: the aforementioned dimensions could be changed/adapted to suit different requirements; and/or that the rigid, welded spacer of the illustrated embodiments could be replaced by a suitably dimensioned swivel unit (not shown).

Thus, when the scaffold clamp 500 of the invention is now applied in place of the known scaffold clamp 18 to the scaffold assembly 10 previously described, the lateral offset 40 of the lower 14 horizontal tube of the ladder beam 16 is removed, in the same way as shown in Figures 4, 5 and 6 of the drawings.

The embodiment of the scaffold clamp 500 of Figures 10 to 14 of the drawings differs from the embodiment described previously principally by the addition of a pair of lateral spacers 510 (or "wings") formed integrally with either side of the claw portions 52.

The wings 510 can enable the scaffold clamp 500 to conform to EN74-1 (2005) for "AA" and "BB" type connections made in scaffolding assemblies.

Specifically, when using one scaffold clamp 500 as a "check fitting", that is to say, immediately below another identical clamp 500 to prevent the said other clamp 500 from slipping downwardly on a vertical scaffold tube when under load, EN74-1 (2005) requires there to be a contact surface between the two fittings, as well as no "interference" between the two fittings. The provision of the wings 510 achieves this, as shown in Figure 11 of the drawings in which two identical scaffold clamps 500 have been fitted to a common vertical scaffold tube 12.

A further advantage of the wings 510 is an improved distribution of forces, as illustrated schematically in Figure 12 of the drawings, for compliance to EN74-1 (2005). Specifically, the wings 510 widen and increase the areal contact between the claw portions 52 and the scaffold tubes. First, by providing a larger part-cylindrical concavity 502 than is the case with a known scaffold clamp, the scaffold clamp 500 is able to better grip a scaffold tube, thereby increasing its resistance to slippage. Second, the scaffold clamp's resistance to bending moments, as indicated schematically by arrow 530 in Figure 12, is greatly improved due to the increase in height of the load-bearing area 502. Third, the scaffold clamp's resistance to cruciform loading, as indicated schematically in Figure 12 by arrows 532 and 534 is greatly increased, compared with known scaffold clamps, due to the increase in width of the load-bearing area 502 in contact with the scaffold tube. In other words, the provision of the wings 510 enables the scaffold clamp 500 to conform to the structural (strength, gripping and flexure) requirements of EN74-1 (2005). It will be noted from Figures 10 to 18 of the drawings, that the wings 510 each have a pair of parallel, planar end surfaces 212 (one at either side). The end surfaces, in the illustrated embodiments of Figures 10 to 18 are 58.5mm apart, but this dimension is purposively selected such that when the end surface 212 of one clamp 500 abuts the releasable clamping portion 54 part of an adjacent clamp 500, as shown in Figure 12 of the drawings, this creates a clamp-on-clamp connection with a precise "tube-on-tube" placement also (i.e. the underside of one scaffold tube 512 rests upon the upper side of another scaffold tube 514). Thus, the aforementioned 58.5mm dimension is not fixed, but is rather a function of certain other dimensions of the clamp (i.e. the width of the clamping portions 54) as well as the outer diameter of the scaffold tubes.

The wings 510, and their carefully selected dimensions, enables a mutually orthogonal connection of scaffold tubes 12, 512, 514, as shown in Figures 13 and 14 of the drawings. The main advantage of this is that it is possible to brace a scaffold assembly 100 (such as that shown in Figure 9 of the drawings) to a wall, with its transom tubes 512 resting directly on top of the cross-members 514. This configuration, which is not possible with existing scaffold clamps, enables the transom tubes 512 to be used to support scaffold boards (not shown) as well as to provide a structural connection to a wall. A similar configuration, when used with known scaffold clamps, requires a first transom tube to be used to support the scaffold boards, and a further, offset transom tube, to brace the scaffold assembly 100 to the wall. In other words, by being able to obtain a clamp-on-clamp and a tube-on- tube configuration (as is the case with the invention), it becomes possible to brace a scaffold assembly to a wall using the same transom tubes that are used to support the scaffold boards.

A further advantage of the scaffold clamps 500 in accordance with the invention is that they permit the formation of a "birds nest" intersection of vertical 12 and horizontal 512, 514 scaffold tubes, also in a tube-on-tube configuration. This is shown in Figures 15 to 18 of the drawings, in which (compared with Figures 13 and 14 of the drawings) the tubes are no longer mutually orthogonal, but rather the transom tube 512 is rotated through 30° or 60° (or indeed any other desired angle). Notably, the wings 510 are configured to extend around their respective scaffold tubes to such an extent that the aforementioned "birds nest" configuration can be obtained whilst maintaining the tube-on-tube configuration.

It will be readily apparent to the skilled person that the invention affords a great many options compared with known scaffold clamps in as much as it now becomes possible to build upwardly off a cantilevered ladder beam, for example, whilst maintaining the correct "lines" of the scaffold assembly. This is, of course, not merely an aesthetic configuration, because now the further scaffold tubes are in-line with the existing one, compatibility issues with other prefabricated units (e.g. walkways, stair units, lifts, access platforms etc.), which are built to certain dimensions are obviated.

The invention defined by the appended claims and is not restricted to the details of the foregoing embodiments, which are merely exemplary.