CN107912050B

CN107912050B - Scaffold clamp

Info

Publication number: CN107912050B
Application number: CN201680035438.0A
Authority: CN
Inventors: 巴里·布朗; 马修·肖尔
Original assignee: Klawz Ltd
Current assignee: Klawz Ltd
Priority date: 2015-04-16
Filing date: 2016-04-14
Publication date: 2021-06-04
Anticipated expiration: 2036-04-14
Also published as: CN107912050A; GB201506455D0; EP3283708A1; GB201601770D0; GB2534092A; GB2537401A; WO2016166541A1; GB2534299A

Abstract

A scaffold clamp (500) comprising spacer wings (512) of carefully selected dimensions to enable scaffold tubes (12, 512, 514) to be connected perpendicular to each other in a tube stacking configuration and/or in a clamp stacking configuration. The present invention facilitates the use of the same transom tubes used to support scaffold panels to reinforce the scaffold assembly to the wall. Another advantage of the present invention is that a "bird's nest" of vertical scaffold tubes (12) and horizontal scaffold tubes (512, 514) can be formed in a tube stack configuration. The scaffold clamp (500) comprises first and second claw portions (52), and a respective set of releasable clamping portions (54) associated with each of the claw portions (52) for securing, in use, a respective scaffold tube (12, 512, 514) between the claw portion (52) and its respective clamping portion (54), wherein the scaffold clamp (500) further comprises a spacer (56, 504) located between the claw portions (52), and wherein each claw portion (52) comprises a pair of wings (512) extending laterally from either side thereof.

Description

Scaffold clamp

The present invention relates to a scaffolding clip adapted to use a portion of a scaffolding system. In particular, and not by way of limitation, the present invention relates to a scaffold clamp comprising spacer wings having carefully selected dimensions to enable scaffold tubes to be connected perpendicular to each other in a tube stacking configuration and/or in a clamp stacking configuration. The present invention may facilitate the use of the same transom tubes used to support scaffold panels to reinforce the scaffold assembly to the wall. Another possible advantage of the present invention is the ability to form a "bird's nest" intersection of vertical scaffold tubes and horizontal scaffold tubes in a tube stacking configuration.

Scaffolding is a system of pipe connectors, panels, ladders and other items that can be connected together to form a frame around, for example, a building. Scaffolding can be used in a number of ways, such as: providing elevated pedestrian access around a building and/or external access to a building, for example, so that a worker can trim or build the building; a temporarily and/or independently supported structure (or a portion thereof), for example to support a display screen of a live event; and to provide temporary structural support to the building during repair work. The application of the scaffold is not limited to the preceding examples, which are exemplary only.

One of the main advantages of the scaffolding is its modularity, enabling it to be highly customized and adapted to specific situations using a relatively small number of different building units. For example, the scaffold tube can be used vertically to provide support for other scaffold tubes arranged horizontally, while other scaffold tubes arranged in sleep can be capped with panels forming walkways. The same pipe may be used to form a guardrail, a cantilever platform, a bracket for a boom, etc. Similarly, the scaffold panels may be used as part of a walkway, perimeter fenders, walls, etc. It will be appreciated that the scope of construction is almost limitless.

When assembling scaffolding, due care and attention is required for safety and structural integrity. Health and safety authorities often mandate the use of scaffold solutions for the population and require that the scaffold be inspected, signed and certified ("tagged") by authorized health and safety personnel before it can be used on site. It will be appreciated that during assembly and disassembly of the scaffold, the scaffold is unproven and so the probability of an accident occurring during such time is greatest.

Two of the main causes of scaffold-related accidents include: accidentally releasing the scaffold parts and then dropping the scaffold parts, thereby causing damage to the structural integrity of the side standers and/or the remaining scaffold; and misalignment of structural scaffold tubes. Many scaffold incidents occur because the scaffold needs to be adjusted to suit a particular application and/or situation where different types of scaffold components (e.g., from different manufacturers/systems) are used together.

From a structural point of view, the main consideration is to ensure that the scaffold tubes are correctly aligned with respect to horizontal and vertical and with respect to each other. The vertical scaffold tubes need to be standard vertical in order to ensure that weight is transferred correctly through them and to minimise bending or buckling that may occur in non-vertical tubes. Similarly, the horizontal tubing needs to be standard horizontal to ensure that passageways, guardrails, etc. do not tilt. In the case of scaffolding assembled from a set of similar components, these requirements are often very easy to meet.

For example, it is known to interconnect scaffold tubes using scaffold clamps comprising a pair of interconnected C-shaped claw members which engage with respective scaffold tubes, and a corresponding pair of clamping portions which securely clamp each scaffold tube to its respective claw member. These general types of scaffold clamps are very common and need no further explanation here. In case the scaffold is assembled using only one type of scaffold clamp, it is quite possible that the spacing between adjacent or overlapping tubes will be the same, thereby ensuring that the sets of scaffold tubes will be correctly aligned, i.e. the horizontal tubes will lie in one plane and the vertical tubes will lie in another plane.

However, in some cases, for example in the case of walkways, it is often more convenient to use ladder beams and girder units which can be hoisted and/or connected to the horizontal scaffold tubes without constructing the walkways from tubes and plates. However, these ladder beams are generally located in a different plane than their supporting scaffold tubes, so adding additional tubes to the ladder beams may result in additional tubes being offset relative to the other tubes. Thus, the only way to interconnect these additional tubes with the rest of the scaffolding is to slightly tilt them, which is often contraindicated

Then, when there are standard vertical and standard horizontal tubes beside the inclined tube, it may be difficult to quickly figure out, by visual inspection, which claws support which tubes, and thus when the scaffold is dismantled (often not in reverse order as assembled), there is a possibility to loosen the incorrect claws, which may result in the parts of the scaffold falling.

The present 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 out in the dependent claims.

According to one aspect of the present invention there is provided a scaffold clamp comprising first and second generally claw-shaped portions, and a respective set of releasable clamping portions associated with each of the claw-shaped portions for securing, in use, a respective scaffold tube between the claw-shaped portion and its respective clamping portion, wherein the scaffold clamp further comprises a spacer between the generally claw-shaped portions selected to provide a spacing of substantially 86.3mm between the centres of superimposed 48.3mm OD scaffold tubes, and wherein each claw-shaped portion comprises a pair of wings projecting laterally from either side thereof.

Another aspect of the invention provides a scaffold assembly comprising a 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 a clamp, wherein the spacer of the scaffold clamp is dimensioned such that the first and second horizontal scaffold tubes are vertically aligned.

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 a scaffold clamp as described herein. Suitably, the dimensions of the spacer of the scaffold clamp are selected so that the vertical scaffold tube is aligned with the further vertical scaffold tube.

A further 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 portion is substantially C-shaped, i.e. adapted to receive/receive scaffold tubes.

The provision of spacers between the claw portions means that the centre of the generally C-shaped claw portions (and hence the centre of the scaffold tube to which they are attached, in use) can be maintained at a desired spacing. Suitably, the desired spacing is different from the spacing of a standard scaffold clamp. Conveniently, the desired spacing is greater than that of a standard scaffold clamp, i.e. a known scaffold clamp may be used on another part of a scaffold assembly comprising a scaffold clamp according to the invention.

Suitably, the spacer comprises a (substantially cubic) protrusion integrally formed with each of the claw-shaped portions. The projections can be permanently connected to one another by, for example, welding to form a spacer between the inner surfaces of the claw portions to maintain them in a fixed spaced apart configuration. Alternatively, the projection may be formed as one piece with only one of the claw portions, and the claw portion may be permanently connected to the other portion of the connector by, for example, welding.

In certain applications, the use of the scaffold clamp of the present invention advantageously enables scaffold tubes to be connected between different types of scaffold systems: in case the planes of the components of the different scaffolding systems are not coplanar, the spacer makes it unnecessary to tilt or misalign further scaffolding tubes or components.

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 in the same orientation (i.e. interconnecting a pair of parallel scaffold tubes) around the spacer; arranged at right angles (i.e. interconnecting a pair of vertical scaffold tubes) around the spacer; or at any desired angle, such as 45 degrees, 30 degrees, 60 degrees, etc.

In another embodiment, the spacer comprises a swivel providing a rotatable connection between the claw portions of the scaffold clamp. Such a configuration may be useful for connecting scaffold tubes to each other at irregular angles and/or enable a single type of scaffold clamp according to the invention to be used in a wider range of applications. The swivel (where provided) may be lockable in a desired relative claw-type orientation, for example, using a splined shaft or a grub screw.

The dimensions of the spacer are selected to ensure that the interconnected tubulars from the different scaffolding systems are coplanar or parallel. The spacers are configured to provide a spacing of approximately 38mm (i.e. 38mm +/-0.5mm, +/-1mm, +/-1.5mm, +/-2mm or +/-manufacturing tolerances) between the outer diameters of the stack, or in one particular embodiment, approximately 86.3mm between the centres of the 48.3mm OD scaffold tubes of the stack. The foregoing dimensions make the scaffold clamp of the present invention ideally suited for use with scaffold assemblies incorporating prefabricated beam units of the Readylok or readylock type.

The scaffold clamp is suitably made of a strong, durable material such as steel, galvanized steel and stainless steel.

Suitably, the claw portions and their respective releasable clamping portions are uniformly shaped and dimensioned to receive, in use, a standardised scaffold tube, such as a 48.3mm OD scaffold tube.

The releasable clamp is suitably removably and/or releasably secured to the claw portion by releasable latching means, for example by a bolt and nut, cam lock means or the like.

Suitably, the scaffold clamp is in accordance with EN74 (and/or any variant thereof). In other words, the scaffold clamp is suitably sufficiently load bearing to enable it to comply with EN74, i.e. to have a sufficient degree of tolerance to slippage, bending moments and cross-shaped loads, so as to comply with structural (strength, clamping and flexing) requirements of, for example, EN74-1 (2005).

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

fig. 3 is a side view of a known scaffold assembly comprising vertical scaffold tubes supporting ladder beams using known scaffold clamps and a transom unit: the ladder beam is inclined due to the transverse dislocation of the upper horizontal pipe fitting and the lower horizontal pipe fitting;

FIG. 1 is a schematic plan view corresponding to FIG. 3, showing that if the ladder beam of FIG. 3 is not tilted, lateral misalignment can occur;

FIG. 2 is a schematic representation of FIG. 1, wherein the components are drawn side-by-side rather than top-to-bottom for clarity;

fig. 6 is a side view of a scaffold assembly including vertical scaffold tubes supporting a ladder beam using an embodiment of a scaffold clamp according to the invention: the ladder beam is now standard vertical;

FIG. 4 is a schematic plan view corresponding to FIG. 6 showing the upper horizontal tube and the lower horizontal tube of the ladder beam being aligned;

FIG. 5 is a schematic representation of FIG. 4, wherein the components are drawn side-by-side rather than top-to-bottom for clarity;

fig. 7 is a plan view of the scaffold clamp of the present invention as shown in fig. 4, 5 and 6;

fig. 8 is a side view of the scaffold clamp of the present invention as shown in fig. 4, 5 and 6;

FIG. 9 shows a schematic perspective view (not to scale) of a scaffold assembly according to an aspect of the invention;

fig. 10 is a perspective view of another embodiment of a scaffold clamp according to the present invention;

FIG. 11 is a side view of two scaffold clamps in the "check joint" configuration as shown in FIG. 10;

FIG. 12 is a perspective view of two scaffold clamps secured to a vertical scaffold tube in a clamp-on-tube configuration as shown in FIG. 10;

FIGS. 13 and 14 are a plan view and a side view, respectively, of the clamp of FIG. 12 for interconnecting three scaffold tubes in a mutually perpendicular relationship;

fig. 15-18 are left and right side, bottom plan and perspective views, respectively, of a scaffold assembly using a scaffold clamp according to the invention.

Referring now to fig. 1, 2 and 3, a known scaffolding assembly 10 includes a vertical scaffolding tube 12 connected to a lower horizontal tube 14 of a ladder beam 16 by a known scaffolding clamp 18. The ladder beam 16 comprises an upper horizontal tube 20 which runs parallel to the lower horizontal tube 14, and the two

horizontal tubes

14, 20 are interconnected at intervals by a support 22.

The upper horizontal tube 20 of the ladder beam 16 engages with the clamping portion 24 of the cross beam unit 25. The clamp portion 24 is formed from steel which is bent into a general M-shape when viewed from above (as shown in figure 2), the limbs 28 of which include C-shaped cut-outs when viewed from the side (as shown in figure 3) for receiving the upper horizontal tube 20 of the ladder beam 16, and the interconnecting portion 30 abuts the vertical scaffold tube 12. The gripping portion 32 securely grips the vertical tubular 12 to the interconnecting portion 30 of the gripping portion 24 to form a rigid connection.

The beam unit 25 comprises a horizontal tube 26, which is directed perpendicular to the ladder beam 16, the horizontal tube 26 supporting the floor surface (not shown) of the passageway.

As can be seen in fig. 1, 2 and 3, the C-shaped cut-out of the clamping portion 24 of the cross beam unit 25 causes the upper horizontal tube 20 of the ladder beam 16 to be displaced inwardly with respect to the lower tube 14 of the ladder beam 16, thereby causing the ladder beam 16 to tilt with respect to the vertical. Even moderate inclinations can significantly affect the structural characteristics of the ladder beam. Furthermore, if another vertical scaffold tube (not shown) is to be dropped from the upper horizontal tube 20 of the ladder beam 16, it is obvious that this other vertical scaffold tube (not shown) will be displaced inwardly with respect to the aforementioned vertical scaffold tube 12.

Structurally, this is significant because it is not possible to extend the other vertical scaffold tube (not shown) upwards and build it on it, or to use it as a structural component of the scaffold assembly 10 because it is not aligned with the remaining vertical scaffold tubes 12 and thus forces cannot be transferred directly from one vertical scaffold tube to the other. Thus, in the event that there is an obstruction above the vertical scaffold tube 12, the existing scaffold assembly 10 does not easily extend upwardly around the obstruction by securing another vertical scaffold tube to and building upwardly from the cantilever ladder beam 16.

Turning now to fig. 4, 5 and 6 of the drawings, the solution is to use a scaffold clamp 50 according to the invention, such as the scaffold clamp shown in fig. 7 and 8 of the drawings. Referring now to fig. 7 and 8 of the drawings, a scaffold clamp 50 according to the invention comprises a pair of generally C-shaped claw portions 52 and a pair of releasable clamping portions 54, the pair of generally C-shaped claw portions 52 engaging the outside diameter of a range of sizes of

scaffold tubes

12, 14, 20, 26. The releasable clamp 54 is pivotally connected to the claw 52 by a pivot 55 so that the clamp 54 can be flipped open to receive the

scaffold tubes

12, 14, 20, 26 in the claw 52. Once inserted, the clamping portions 54 can be pivoted into engagement and the bolt and nut arrangement 57 fitted between the claw portions 52 and the clamping portions 54 firmly and rigidly clamps the

scaffold tubes

12, 14, 20, 26 in place, thereby thereafter inhibiting or preventing relative movement of the

scaffold tubes

12, 14, 20, 26 and the scaffold clamp 50 until released.

As previously mentioned, the scaffold clamp 50 of the present invention also includes a spacer 56 which, in the illustrated embodiment, 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 spacers 56 space the inner surfaces 59 of the C-shaped claw portions 52 apart by 18mm, so that the outer diameters of the

scaffold tubes

12, 14 are spaced apart by 38mm 61 (or 86.3mm 63 apart at their centres). In the illustrated embodiment, the dimension 61 of 38mm corresponds to the previously described lateral offset 40 of the upper horizontal tube 20 from the lower horizontal tube 14 of the ladder beam 16.

Thus, when the scaffold clamp 50 of the present invention is now applied to the previously described scaffold assembly 10 in place of the known scaffold clamp 18, the amount of cross-beam misalignment 40 of the lower horizontal tube 14 of the ladder beam 16 is eliminated. This is illustrated in figures 4, 5 and 6 of the drawings.

Referring now to fig. 4, 5 and 6 of the drawings, the lower horizontal tube 14 of the ladder beam 16 is now connected to the vertical scaffold tube 12 using the scaffold clamp 50 according to the present invention, and the spacer 56 now compensates for the amount of misalignment of the transom unit 25 relative to the vertical scaffold tube 12. In particular, in fig. 6, it can now be seen that the ladder beam 16 is vertically aligned such that its supports 22 are now parallel with the vertical scaffold tube 12.

This has several advantages, including: improved structural integrity as compared to the configurations of fig. 1, 2 and 3; and the ladder beam 16 is now used within the design specifications/parameters. Most notably, however, the scaffold clamp 50 of the present invention enables the scaffold assembly 100 to be extended up out of the ladder beam 16 using yet another vertical scaffold tube, so long as such yet another vertical scaffold tube (not shown) is connected to the upper 20 or lower 14 horizontal tube of the ladder beam 16 using the scaffold clamp 50 according to the present invention. In such a case, further vertical scaffold tubes (not shown) are displaced outwardly (by spacers 56) relative to the ladder beams so that they are in line with (i.e. coplanar with) the existing vertical scaffold tubes 12.

Turning to fig. 9 of the drawings, a scaffold assembly 100 according to aspects of the invention includes three vertical scaffold tubes 12 connected to a horizontal scaffold tube 156 using known scaffold clamps 18. The horizontal ladder beam 16 is connected to two of these vertical scaffold tubes 12 using a scaffold clamp 50 according to the present invention, which provides a lateral offset 40 between the flat 150 of the vertical scaffold tubes 12 and the flat 154 of the ladder beam 16.

The passage surface 251 is supported on a pair of beam units 25 which, as previously described, are connected to the ladder beam 16 by branches 28 as previously described.

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

With the scaffold clamp 50 according to the invention, the scaffold assembly 100 is extended laterally by supporting further vertical scaffold tubes 120 in overhanging portions extending beyond the ladder beam 16. The spacer 56 of the scaffold clamp 50 of the present invention compensates for the amount of misalignment 40 between the flat surface 154 of the ladder beam 16 and the flat surface 150 of the vertical scaffold tube 12. Thus, the further vertical scaffold tubes 120 are coplanar 150 with the remaining vertical scaffold tubes 12, 12'.

This configuration enables yet other scaffold tubes 120 to be mated to other vertical scaffold tubes using horizontal scaffold tubes 156 and known scaffold clamps 18. Thus, the scaffold assembly 100 according to the present invention enables all horizontal scaffold tubes 156 to share a uniform plane 152 and all

vertical scaffold tubes

12, 120 to also share a uniform plane 150. This greatly facilitates the assembly and disassembly of the scaffold 100; provides improved structural integrity and maintains the correct "alignment" of the scaffold assembly 100 to meet certain mandatory health and safety requirements.

Referring now to fig. 10 to 18 of the drawings, another embodiment of a scaffold clamp according to the invention is substantially as previously described, with the exception of a number of modifications as described below. Identical reference numerals are used to identify identical features to those previously described, only to avoid redundancy herein.

In fig. 10 to 18, the scaffold clamp 500 comprises a pair of claw portions 52 each comprising a part-cylindrical concave surface 502 which, in use (but not shown in fig. 10), engages the outer diameter of a scaffold tube (not shown); and a pair of releasable clamp portions 54.

The releasable clamp 54 is pivotally connected to the claw 52 by a pivot 55 so that the clamp 54 can be flipped open to receive scaffold tubulars in the claw 52. Once inserted, the clamping portions 54 can be pivoted into engagement and the bolt and nut arrangement 57 fitted between the claw portions 52 and the clamping portions 54 firmly and rigidly clamps the scaffold tube in place, thereby inhibiting or preventing relative movement of the scaffold tube and the scaffold clamp 500 thereafter until released.

As previously mentioned, the scaffold clamp 500 of the present invention further comprises a spacer 56 which, in the embodiment shown in figures 10 to 18 of the drawings, comprises a generally cubic protrusion 504 integrally formed with each claw 52: the cube-shaped projections 504 are 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 previously described, the spacers 56 space the inner surfaces of the claw portions 52 apart by 18mm so that the outer diameters of the scaffold tubes are spaced apart by 38mm (or their centres are spaced apart by 86.3 mm). In the illustrated embodiment, the dimension of 38mm corresponds to the previously described lateral offset 40 of the upper horizontal tube 20 from the lower horizontal tube 14 of the ladder beam 16.

Thus, when the scaffold clamp 500 of the present invention is now applied to the previously described scaffold assembly 10 in place of the known scaffold clamp 18, the amount of cross-beam misalignment 40 of the lower horizontal tube 14 of the ladder beam 16 is eliminated in the same manner as shown in fig. 4, 5 and 6 of the drawings.

The embodiment of the scaffold clamp 500 of fig. 10-14 of the drawings differs in principle from the previously described embodiments by the addition of a pair of lateral spacers 510 (or "wings") which are integrally formed with either side of the claw 52.

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

Specifically, when using one scaffold clamp 500, i.e. another identical clamp 500, abutting below, as a "check joint" to prevent said other clamp 500 from slipping down on the vertical scaffold tube when under load, EN74-1(2005) requires that there should be a contact surface between the two joints and that there should not be "interference" between the two joints. This is achieved by providing wings 510, as shown in figure 11 of the drawings, in which two identical scaffold clamps 500 are coupled to a common vertical scaffold tube 12.

Another advantage of the wings 510 is that the distribution of the forces is improved, as schematically illustrated in fig. 12 of the drawings, so as to comply with EN74-1(2005), precisely the wings 510 widen and increase the surface contact between the claw 52 and the scaffold tube. First, by providing a larger part-cylindrical concavity 502 than in the case of known scaffold clamps, the scaffold clamp 500 is able to better grip scaffold tubes, thereby increasing its anti-slip properties. Secondly, the performance of the scaffold clamp against bending moments, as indicated schematically by arrow 530 in fig. 12, is greatly improved as the height of the load bearing area is increased. Third, the resistance of the scaffolding clamp to cross-loads, as indicated schematically by

arrows

532 and 534 in figure 12, is greatly improved by the increased width of the load bearing area in contact with the scaffolding tubing as compared to known scaffolding clamps. In other words, the provision of the wings 510 enables the scaffold clamp 500 to comply with the structural (strength, clamping and flexing) requirements of EN74-1 (2005).

From fig. 10 to 18 of the drawings, it will be noted that the wings 510 each have a pair of parallel flat end surfaces (one on either side). The end surfaces in the embodiment illustrated in fig. 10-18 may be 58.5mm apart, but this dimension is purposefully selected so that when the end surface of one clamp 500 abuts the releasable clamping portion 54 portion of an adjacent clamp 500, as shown in fig. 12 of the drawings, this constitutes a clamp-on-stack connection with a precise "pipe-on-stack" arrangement (i.e., the underside of one scaffold tube 512 is on the upper side of the other scaffold tube 514). Thus, the aforementioned dimension of 58.5mm is not fixed, but is a function of some other dimension of the clamp (i.e., the width of the gripping portion 54) and the outer diameter of the scaffold tube.

The wings 510 and their carefully selected dimensions enable the

scaffold tubes

12, 512, 514 to be connected perpendicular to each other as shown in figures 13 and 14 of the drawings. This has the major advantage that it is possible to reinforce a scaffold assembly 100 (e.g., the scaffold assembly shown in fig. 9 of the drawings) to a wall with its cross-beam tube 512 placed directly on top of the cross-beam member 514. This configuration, which is not possible with existing scaffold tubes, enables the transom tubes 512 to be used to support scaffold panels (not shown) and provide structural connection to the wall. A similar configuration, when used with known scaffold clamps, requires the use of a first cross-beam tube to support the scaffold plates and another misaligned cross-beam tube to reinforce the scaffold assembly 100 to the wall. In other words, by being able to obtain a clamp and tube stacking configuration (as is the case with the present invention), it becomes possible to reinforce the scaffold assembly to the wall using the same transom tubes for supporting the scaffold plates.

Another advantage of the scaffold clamp 500 according to the invention is that it is possible to form a "bird nest" intersection of vertical scaffold tubes 12 and

horizontal scaffold tubes

512, 514 in a tube stacking configuration. This is illustrated in fig. 15-18 of the drawings, where (as compared to fig. 13 and 14 of the drawings) the tubes are no longer perpendicular to each other, but rather the cross beam tube 512 is rotated to 30 ° or 60 ° (or indeed to any other desired angle). Notably, the wing portions 510 are configured to extend around their respective scaffold tubes to an extent that enables the aforementioned "bird nest" configuration to be achieved while maintaining the stacked configuration of the tubes.

It will be readily apparent to the skilled person that the present invention provides a number of alternatives compared to known scaffolding clamps, since the projecting cantilever ladder beam is built up upwards while, for example, maintaining the correct "straight line" of the scaffolding assembly now becomes possible. Of course, this is not only an aesthetically pleasing construction, since now some scaffold tubes are lined up with existing scaffold tubes, compatibility problems with other prefabricated units built to certain dimensions (e.g. walkways, stairway units, lifts, access platforms, etc.) are eliminated.

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

Claims

1. A scaffold clamp (500), comprising:

a first claw portion, and a first releasable clamp portion which, in use, secures a first scaffold tube between the first claw portion and the first releasable clamp portion;

a second claw portion, and a second releasable clamp portion which, in use, secures a second scaffold tube between the second claw portion and the second releasable clamp portion;

a fixed spacer (56) disposed between the first and second claw portions and providing a rigid connection therebetween;

the first claw comprises a first pair of wings projecting laterally from either side of the first claw, each wing of the first pair of wings comprising a flat end surface, the flat end surfaces of the first pair of wings being parallel to each other;

the second claw comprising a second pair of wings projecting laterally from either side of the second claw, each wing of the second pair of wings comprising a flat end surface, the flat end surfaces of the second pair of wings being parallel to each other;

the method is characterized in that:

in use, in an arrangement comprising first, second and third scaffold tubes, when fixing the scaffold clamp (500) on the first and second scaffold tubes and fixing a second identical scaffold clamp (500) on the first and third scaffold tubes, the spacer (56) and the spacing between the parallel flat end surfaces of each of the first and second pairs of wings are dimensioned such that:

forming a clamp stack connection on the first scaffold tube when the flat end surface of one scaffold clamp (500) abuts the first and second claw portions of the other scaffold clamp (500);

a tube stack connection is formed in which the lower side of the second scaffold tube is located at the upper side of the third scaffold tube.

2. The scaffold clamp (500) of claim 1, wherein the first and second pair of wings are integrally formed with the first and second claw portions.

3. The scaffold clamp (500) of claim 1, wherein each of the first and second claw portions comprises a part-cylindrical concave surface adapted to engage an outer diameter of the first scaffold tube in use, and wherein the part-cylindrical concave surfaces are formed in the first and second claw portions and in each of the first and second pairs of wings.

4. The scaffold clamp (500) of claim 1, wherein the flat end surfaces are 58.5mm apart.

5. The scaffold clamp (500) of any of claims 1 to 4, wherein the dimensions of the spacer (56) are selected to provide a 86.3mm spacing between the centres of overlapping 48.3mm OD first scaffold tubes, thereby ensuring that the interconnected first scaffold tubes are coplanar or parallel.

6. The scaffold clamp (500) of any one of claims 1 to 4, wherein the first and second claw portions are arranged around the spacer (56) in any one of the group consisting of: the same orientation; at right angles to each other; at 30 degrees to each other; at 45 degrees to each other; and at 60 degrees to each other.

7. The scaffold clamp (500) of any of claims 1-4, wherein the spacer (56) comprises a protrusion (504) integrally formed with either or both of the first and second claw portions; and wherein each of the protrusions (504) is permanently connected to each other or to the first and second claw portions by welding.

8. The scaffold clamp (500) of any of claims 1 to 4, wherein the first and second claw portions and their respective first and second releasable clamp portions are uniformly shaped and dimensioned to receive, in use, a standardised scaffold tube and the standardised scaffold tube has an outer diameter of 48.3 mm.

9. The scaffold clamp (500) of any one of claims 1 to 4, wherein the first and second releasable clamping portions are pivotally secured to the first and second claw portions by a pivot (55) and comprise releasable locking means comprising a bolt and nut (57) or cam lock cooperating between the first and second claw portions and the first and second releasable clamping portions.

10. The scaffold clamp (500) of any one of claims 1 to 4, wherein the scaffold clamp (500) is load bearing and conforms to EN 74: has sufficient anti-slip, bending moment and cross-shaped load properties to meet the requirements of EN74-1(2005) with respect to structural strength, clamping and flexing.

11. A scaffold assembly comprising a pair of scaffold tubes interconnected by the scaffold clamp (500) of any one of claims 1 to 10.

12. The scaffold assembly of claim 11, comprising any one or more of the group consisting of:

a. a transverse scaffold tube connected to a vertical scaffold tube by a first said scaffold clamp (500) and a transom scaffold tube connected to said vertical scaffold tube by a second said scaffold clamp (500), wherein said transverse scaffold tube and transom scaffold tube are in tube stacking contact;

b. a transverse scaffold tube connected to a vertical scaffold tube by a first said scaffold clamp (500) and a second said scaffold clamp (500) connected to said vertical scaffold tube adjacent below the first said scaffold clamp (500), wherein the flat end surfaces of the first and second pair of wings of the first scaffold clamp (500) are in contact with the first and second claws (52) of the other scaffold clamp (500);

c. at least one vertical scaffold tube connected to a first horizontal scaffold tube (20) forming part of a ladder beam (16), and wherein a second horizontal scaffold tube (14) forming another part of the ladder beam (16) is affixed to the vertical scaffold tube by a scaffold clamp (500) according to any of claims 1 to 10, wherein the spacer (56) of the scaffold clamp (500) is dimensioned such that the first (20) and second (14) horizontal scaffold tubes of the ladder beam (16) are vertically aligned.

13. The scaffold assembly of claim 12, wherein the second horizontal scaffold tube (14) is affixed to the vertical scaffold tube by the first and second releasable clamping portions forming part of a transom unit.

14. The scaffold assembly of claim 11 or claim 12, further comprising another vertical scaffold tube affixed to the ladder beam (16) by a scaffold clamp (500) of any of claims 1 to 10, and wherein the dimensions of the spacer (56) of the scaffold clamp (500) are selected so that the vertical scaffold tube is aligned with the other vertical scaffold tube.