GB2360316A

GB2360316A - Suspended scaffold system with stabilising restraint wire

Info

Publication number: GB2360316A
Application number: GB0006158A
Authority: GB
Inventors: Patrick Anthony Murphy
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-03-14
Filing date: 2000-03-14
Publication date: 2001-09-19
Also published as: WO2001069008A3; WO2001069008A2; AU4082101A; GB0006158D0

Abstract

A system comprises a suspension cable, at least one restraint wire (36), including a portion for attaching to a structure, and a scaffold unit (20) including at least one restraint guide (Fig. 4, 44), where the restraint wire is used to control the position of the platform in a direction perpendicular to a direction of suspension. Preferably the restraint wire is secured at or near the top of a structure and may also be secured at or near the bottom of a structure or secured to a weight. The restraining guide may comprise a roller or wheel and may be moveable, on the scaffold unit. In an alternative embodiment (Figures 7 and 8) a scaffold system comprises a first anchor point located at or near the bottom of a first side of a structure, a scaffold unit suspended from a second side of a structure and a cable attached both to the scaffold unit and the first anchor point.

Description

2360316 SCAFFOLDING SYSTEM The invention relates to scaffolding systems of

a kind used in building construction and building maintenance. More particularly, it relates to a suspended scaffolding system, which provides for a simplification in scaffolding system structure, and an improvement in the flexibility of use and reliability of scaffolding systems, whilst affording a reduction in operating costs.

Access platforms have long been used on buildings as a platform from which to perform inspection and maintenance tasks. For example, the painting of the, exterior of a building or the washing of the windows of a building might require an access platform. Alternatively, an inspection or survey of the entire exterior of a building might be required. Access platforms for such inspection and maintenance activities are conventionally of a type that comprises a cradle suspended from the top of a building by means of cables. The cables are attached to the cradle and dispensed from booms positioned on the top of the building. In such a conventional system, the vertical position of the cradle is determined by means of a winch provided on the cradle or on the booms.

More recently, there has been a requirement for such suspended systems to be permanently installed on newly constructed buildings. A permanently installed conventional access system is shown in Figure 1. The conventional system comprises a cradle 10 which is suspended from a suspension system 11 provided on the top of a building 1, by means of cables. 16. The suspension system 11 of Figure 1 comprises booms 12 which are secured to the top of the building 1, which booms guide the cables 16 and determine the separation between the cradle 10 and the exterior face of the building. The cradle is moved up and down the vertical direction by means of a winch provided on the cradle 10 or the suspension system 11 to give access to the full height of the building 1. In such a conventional system, the cradle 10 is often subject to forces which cause the cradle to move in an undesirable fashion. For example, the cradle can be moved by exposure to strong winds, which movement can be prejudicial to the safety of the operators or the integrity of the building.

2 Cradles in conventional access systems are often of a considerable weight. Moreover, the cradles are usually designed to carry significant loads. Thus, the permanently installed suspension systems of conventional access systems are designed to withstand large forces. Accordingly, conventional suspension systems need to be very firmly fixed to the top of the building. In addition, a counter-balance weight 14 is required to balance the weight of the cradle, as is shown in Figure 1 - The conventional system shown in Figure 1 only provides access to part of one of the vertical exterior faces of the building 1. However, access to the entire vertical exterior surface of a building is frequently required. In a conventional system of the type shown in Figure 1, a railing is provided around the perimeter of the top of the building. A trolley moves on the railing to move the cradle in the horizontal direction from one position to another on the exterior surface of the building. As discussed above with reference to the suspension system, the railing needs to be very firmly secured to the top of the building to withstand the large forces applied by the weight of the cradle.

The conventional access system shown in Figure 1 is beset by a significant problem, in that a permanently installed system requires frequent safety inspections. Conventional access systems are often used for a small number of weeks over an entire year. Thus, the operational costs can be unduly burdensome, especially when it is considered that access systems which are installed on newly constructed buildings can be required to be kept operational for periods of more than twenty years.

A further problem resides in the inspection and maintenance of buildings which were completed before the introduction of requirements to install access systems at the time of construction. As discussed above, access systems are of a substantial weight and require firm attachment to a building for safe operation. Measures taken to ensure the' safe operation of conventional access systems which are installed at the time of construction of a building can often involve considerable labour and material. The installation of conventional access systems after the completion of the construction of a building can often be considerably more complex and costly.

3 Moreover, irrespective of whether installation takes place before or after completion of construction of a building, the installation and operation of a conventional access system on a building is complex and costly and provides an access system that is inflexible in use.

Thus, there is a requirement for an access system which is simple to install and flexible to operate, and which affords a reduction in the access system inspection regime without compromising on safety.

In a first aspect the present invention relates to a scaffolding system comprising: a suspension cable; at least one restraint wire comprising a portion for securing to a structure; a scaffolding unit for suspension from a structure by means of the suspension cable, said scaffolding unit comprising at least one restraint guide for said restraint wire; and said at least one restraint wire is for controlling the position of said scaffolding unit in a direction perpendicular to a direction of suspension.

In a second aspect the present invention relates to a scaffolding system comprising: a first anchor point for disposal towards or at the bottom of a first elevation of a building; a scaffolding unit for suspension from or adjacent a second elevation of a building opposite said first elevation; and a first cable for disposal on a building and for coupling to said suspended scaffolding unit, said cable comprising a first portion at or towards one end of the cable for securing to said first anchor point.

In a third aspect the present invention relates to a scaffolding system comprising: at least one anchor point for permanent disposal towards or on the top of a building; at least one suspension system for removeably coupling with said at least one anchor point; and a scaffolding unit for temporary suspension adjacent a building from said at least one suspension system.

In a fourth aspect the present invention relates to a scaffolding system for temporary disposal on a building comprising: at least one cable; at least one member for removeable disposal on a building and for supporting of 4 said at least one cable; a scaffolding unit for suspension from or adjacent a building; at least one suspension element provided on said scaffolding unit for attachment to a portion of said at least one cable.

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

Fig. 1 is a representation of a conventional access system; Fig. 2 is a representation of a scaffolding system according to the present invention; Fig. 3 is a representation of a view of the scaffolding unit shown in Fig. 2; Fig. 4 is a representation of another view of the scaffolding unit shown in Fig. 2; Figs. 5a, 5b and 5c are examples of building attachments according to the present invention; Fig. 6 is a representation of a view of another embodiment of the scaffolding unit shown in Fig. 2; Fig. 7 is a representation of a first method of use of a scaffolding system according to the present invention; Fig. 8 is a representation of a second method of use of a scaffolding system according to the present invention; Figs. 9a to 9e is a representation of a third method of use of a scaffolding system according to the present invention; Figs. 10a to 10d is a representation of a fourth method of use of a scaffolding system according to the present invention; Figs 11 a and 1 lb are a representation according to another embodiment of the present invention; Fig. 12 is a representation of ground anchor points for use with the scaffolding system of Figs. 11 a and 1 lb; Fig. 13 is a representation of a roof anchor point for use with the scaffolding system of Figs. 11 a and 1 lb; Fig. 14 is a detailed representation of a roof anchor point; Fig. 15 is a detailed representation of another example of roof anchor points; Fig. 16 is a representation of a roof cable support for use with the scaffolding system of Figs. l la and l lb; Fig 17 is a top view of a roof cable support arrangement for use with the scaffolding system of Figs. 11 a and 1 lb.

Figure 2 shows a scaffolding unit 20 suspended from the roof of a building 1 by means of cables 16 dispensed from a suspension system 11. The suspension system 11 comprises a boom 12 and members for supporting the boom on the roof of building 1. A counter-balance weight or securing point 14 is provided in the suspension system 11 to balance the weight of the scaffolding unit 20, as discussed above. According to the present invention, the suspension system 11 and scaffolding unit 20 are temporarily disposed on the roof of the building 1. This means of disposal is in contrast to the aforementioned conventional access system wherein the.cradle 10 of Figure 1 is permanently installed on the roof of the building 1. As discussed above, a building access system needs to be secured to the roof of the building to provide for safe operation. Accordingly, the temporary access system of the present invention is secured to the roof of the building 1 of Figure 2 by means of anchor points which are permanently installed on the roof of the building. Such anchor points can be installed on the roof or towards the upper part of a building either during or after construction. However, it is preferred that the anchor points are installed during construction of a building. It is preferred that the anchor points are of a simple and low cost nature, in that they are structurally uncomplicated and comprised of standard materials and components. The anchor points provide a means of temporarily securing a suspension system and suspending a scaffolding unit or access platform in a safe manner. Examples of anchor points are described below in more detail with reference to Figures Sa to 5c. Thus, the according to the present invention anchor points are permanently installed on or towards the roof of a building. The anchor points provide a safe means of attachment of a suspension system and the suspension of a scaffolding unit to enable work to be carried out on the vertical exterior faces of the building. Once work on the building is complete the 6 suspension system and scaffolding unit can be removed from the building leaving only the anchor points remaining on the building. The suspension system and scaffolding unit can then be relocated to another building, which is provided with similar such anchor points, for work to be carried out on that other building. In contrast, the conventional access system of Figure 1 comprises a permanently installed suspension system 11 and cradle 10. Providing such a conventional access system on a building involves considerable expenditure on the part of the building contractor or building owner. Furthermore, a conventional access system usually comprises moving parts or is of a complexity which requires frequent maintenance. Moreover, safety requirements are such that frequent safety inspections are required. On the other hand, the access system according to the present invention confers the significant benefits of reducing installation and operating costs.

Figure 3 is a detailed representation of the scaffolding unit 20 shown in Figure 2. The scaffolding unit 20 comprises one or more work platforms 22 each of which are fixed to two or more ladder sections 24. Ladder sections 24 function primarily as vertical supports for the work platforms 22. The provision of rungs 26 on the ladder sections 24 facilitates the vertical movement of persons from one work platform 22 to another. The strength of the scaffolding unit 20 can be increased by the inclusion of support sections 28. A suspension beam 30 is attached to the scaffolding unit to provide a means of attachment for the suspension cables. The suspension beam 30 can be provided at the top of the scaffolding unit 20, as shown in Figure 3. Alternatively, the suspension beam can be provided at a lower part of the scaffolding unit, and to improve stability the suspension cables can be attached to or fed-through the upper portions of the scaffolding unit.

It is preferred that the suspension beam 30 of a scaffolding unit 20 includes a truss to strengthen the suspension beam 30. Usually the truss is a bowstring truss of a kind shown in Figure 3. The bowstring truss of Figure 3 comprises a cable 34, which is supported on spacers 32 provided on the suspension beam 30 and is attached to either end of the suspension beam 30. Usually, the cable 34 of the bowstring truss is under tension.

7 It is preferred that the scaffolding unit 20 comprises a material handling bar 38, as shown in Figure 3. The material handling bar 38 provides a handling system for the likes of glass panes and construction panels. Usually, the material handling bar 38 is provided towards the upper portions of the scaffolding unit, although the material handling bar 38 can be installed at any position on the scaffolding unit 20.

Of course, it will be appreciated by the skilled person that the scaffolding unit shown in Figure 3 is merely illustrative and that modifications and variations can be made to the individual components and the overall structure of the scaffolding unit without changing its basic function.

According to the present invention, a scaffolding unit 20 is provided with at least one restraint wire 36. The restraint wire 36 is connected at its upper end to the suspension system of the scaffolding system. The restraint wire is suspended in a direction substantially between the suspension system and the ground and is mechanically coupled to the scaffolding unit 20. The function of the restraint wire is to restrict movement of the scaffolding unit 20 in directions perpendicular to the direction of suspension of the unit 20, which direction of suspension is usually the direction of movement of the scaffolding unit 20 in relation to a building under maintenance or inspection. As shown in Figure 3, two restraint wires 36are provide at either end of a side of the scaffolding unit 20, which side faces away from the building 1 under maintenance or inspection. The two restraint wires 36 can be provided at any position along the side of the scaffolding unit 20 which faces away from the building 1. Any number of restraint wires 36 can be provided along the side of the scaffolding unit 20 which faces away from the building 1. In a preferred embodiment, two restraint wires 36 are provided along the side of the scaffolding unit 20, at or towards either end of the side. Restraint wires positioned along a side of a scaffolding unit facing away from a building are referred to as rear restraint wires. Rear restraint wires restrict movement of a scaffolding unit 20 in a direction which is perpendicular to the direction of suspension of the scaffolding unit and in line with a direction of disposition of the scaffolding unit 20 in relation to a building 1.

Figure 4 is a side view of the scaffolding unit 20 shown in Figure 3. The scaffolding 8 unit 20 is shown in relation to a building 1, which is under maintenance or inspection. The end view of the scaffolding unit of Figure 4 shows a vertical ladder section 24 provided, with rungs 26. One of the two rear restraint wires 36 of Figure 3 is shown in Figure 4. In addition, Figure 4 shows an additional restraint wire 42, which is referred to as a side restraint wire. The side restraint wire 42 is attached at an upper end to the suspension system on the roof of a building and is suspended in a direction substantially between the suspension system and the ground. The side restraint wire 42 is mechanically coupled to the scaffolding unit 20. In a preferred embodiment, a side restraint wire 42 is provided at either side of the scaffolding unit 20. More than one side restraint wire 42 can be provided at either side of the scaffolding unit 20 if required. The side restraint wire 42 restricts movement of a scaffolding unit 20 in a direction which is perpendicular to the direction of suspension of the scaffolding unit and perpendicular to a direction of disposition of the scaffolding unit 20 in relation to a building 1.

A side restraint wire 42 can be mechanically coupled to the scaffolding unit 20 by means of a loop arrangement, which is provided on the side of the scaffolding unit, and through which the side restraint wire is fed. Alternatively, the side restraint wire can be mechanically coupled by means of a wire guide arrangement 44, which is provided on the side of the scaffolding unit as is shown in Figure 4. Such a wire guide arrangement takes the form of a member in which a channel is formed, which channel acts to accommodate the side restraint wire 42. Alternatively, the side restraint wire 42 can be mechanically coupled by means of one or more pulley arrangements 40, as shown in Figure 4. As stated above, the rear restraint wires 36 are mechanically coupled to the scaffolding unit 20. Any one of the means of mechanical coupling described above with reference to the side restraint wires 42 can be used with the rear restraint wires 36. It is preferred that a pulley arrangement 40 is used with the rear restraint wires, as shown in Figure 4.

The rear and side restraint wires 36, 42 of the present invention are, as is discussed above, secured at an upper end to a suspension system and mechanically coupled to a scaffolding unit. The rear and side restraint wires extend towards another end below the scaffolding unit where the restraint wires are attached to a weight, which weight is disposed 9 on the ground or suspended below the scaffolding unit. Alternatively, the restraint wires are attached to the ground or some portion of a building at or towards the ground.

As discussed above with reference to Figure 2, according to the present invention the provision of anchor points, which are permanently installed on a building, permits removal of the suspension system and scaffolding unit. Figures 5a to Sc provide examples of permanently installed anchor points. In Figure 5a, an anchor point 50 is provided on a portion of a roof of a building 1. The anchor point of Figure 5a comprises a portion 54 which is embedded within the material of the roof of the building. A second portion 52 of the anchor point 50 extends above the level of the roof of the building. The second portion 52 includes a means for securing a suspension system, which means might comprise a hoop for accommodating a boom of a suspension system, as shown in Figure 5a. Figure 5b shows a different embodiment of the arrangement of Figure 5a. In Figure 5b, the first portion 54 of anchor point 50 is embedded in an up-stand 5 provided as part of the structure of the roof of building 1. In both Figure 5a and Figure 5b, the second portion 52 of the anchor point 50 comprises an extended portion to raise the means for securing the suspension system above the level of the roof. Figure 5c shows another arrangement of an anchor point in more detail than the anchor points shown in Figures 5a and 5b. The anchor points 50 of Figure 5c comprises a member 54 secured to building 1 by means of securing elements 56. The securing elements can be rivets, bolts or the like and are embedded in the building 1 at the time of construction of the building or at a later time. Embedding of the securing elements 56 after the building has been constructed can be achieved by, for example, drilling of the material of the building followed by the cementing or gluing in place of the securing elements 56. The anchor point 50 of Figure 5c comprises a bracket 58 which is attached to the member 54. Alternatively, the bracket 58 can form part of the temporarily installed suspension system. As shown in Figure 5c, a boom 12 of a suspension system is secured to the bracket 58 of the anchor point 50 by means of a bolt 60.

Figure 6 is a side view of an alternative embodiment of the scaffolding unit 20 shown in Figure 4. In Figure 4, the scaffolding unit 20 is adjacent a building 1. Similarly to that as described above with reference to Figure 4, the scaffolding unit 20 of Figure 6 comprises a rear restraint wire 36, a side restraint wire 42 and restraint wire guides 40, 44. As shown in Figure 6, the scaffolding unit 20 comprises a work platform 64, the position of which can be fixed anywhere between the upper and lower portions of the scaffolding unit 20. In addition, it is preferred that the scaffolding unit comprises means for preventing the scaffolding unit 20 from coming into contact with a building. As shown in Figure 6, such means can take the form of a roller 66, which is attached to the building side of the scaffolding unit 20.

Typically, a scaffolding unit of the kind shown in Figure 4 has a Safe Working Load (SWL) of 1000 kg. The SWL can be increased to 2000kg by means of a truss 68 provided on a work platform to strengthen the work platform, as shown in Figure 6. It is preferred that the truss is of a bowstring type, as discussed above with reference to Figure 3.

Figure 7 provides an illustration of a first method of use of a scaffolding system according to the present invention. Two scaffolding units 20 are shown as being suspended from the building 1 of Figure 7. The scaffolding.unit and suspension system provided on either side of the building 1 of Figure 7 are not connected to each other. Thus, this arrangement is referred to as a non-continuous arrangement. The suspension system 11, which suspends each scaffolding unit 20, comprises a boom 12, a suspension cable 16 and a main support. The main support of the suspension system takes the form of a permanent anchor point as. described above, in particular with reference to Figure 5. As discussed above, the weight of the scaffolding unit 20 needs to be compensated for, for safe operation of the scaffolding system. The weight compensator, which is represented by component 70 in Figure 7, takes the form of a cast-in connection to a roof slab, an up-stand or a temporary arrangement, which temporary arrangement might comprise weights. The weight compensator 70 can be either wholly or partially installed on a building. For example, a compensator might comprise an embedded element, as discussed with reference to the anchor points of Figures 5a, 5b and 5c, which can be temporarily connected to a cable attached to the end of a boom of a suspension system. Alternatively, the cable and embedded element might be provided permanently on the roof of the building. The permanent components of a compensator can be installed either during construction of a 11 building or after completion of a building. A permanently installed compensator according to the present invention is structurally simple and is comprised of a few low cost parts. It is preferred that the scaffolding system shown in Figure 7 includes rear and/or side restraint wires 36, which restraint wires are described above with reference to Figures 3 and 4. The rear and side restraint wires 36 restrict the movement of the scaffolding unit 20 in directions perpendicular to the direction of suspension of the scaffolding unit. Alternatively, in the scaffolding system of Figure 7 the suspension system can be entirely temporary, i.e. no permanently installed anchor points or compensators are provided on or towards the roof of building 1. In this arrangement, stability of the main support can be achieved by means of use of a floor- slab, and the weight compensation achieved by means of weight boxes.

Figure 8 provides an illustration of a second method of use of a scaffolding system according to the present invention. Two scaffolding units 20 are shown as being suspended from the building 1 of Figure 8. The suspension system 11, which suspends each scaffolding unit 20, comprises a boom 12, a suspension cable 16 and a main support. The main support of the suspension system can take the form of a permanent anchor point as described above, in particular with reference to Figure 5. Alternatively, the main support can be entirely temporary, e.g. a steel or scaffolding structure or a wheeled assembly. The scaffolding system of Figure 8 comprises a connection member 72 which connects suspension systems 11 provided on opposing side of a building 1. Thus, the arrangement shown in Figure 8 is referred to as a continuous arrangement. The connection member can be a cable or a solid member. It is preferred that the scaffolding system comprises a truss arrangement to strengthen the connection between suspension systems on opposing sides of a building. As shown in Figure 8, a typical truss arrangement is a bowstring truss 74 comprising a cable supported by spacers provided on the suspension systems 11 and the connection member 72. In addition, it is preferred that each scaffolding unit 20 is provided with rear and/or side restraint wires 36. The restraint wires 36 are connected at an upper end to a suspension system 11 and are coupled to a scaffolding unit. The restraint wires are connected at a lower end either to a weight suspended below the scaffolding unit or to the ground or some portion of a building.

12 The method of use shown in Figure 8 provides the means to counter-balance the weight of the two scaffolding units 20. When the two scaffolding units 20 are in a similar lie and are bearing similar loads the two scaffolding units are self-balancing, i.e. one scaffolding unit acts as a balance to the other scaffolding unit. When the scaffolding units are in a different lie or are bearing dissimilar loads the restraint wire of each scaffolding unit provides a balancing force for the opposing scaffolding unit, which balancing force is coupled via the suspension systems 11 and connection member 72.

Figures 9a to 9e are a representation of a third method of use of a scaffolding system according to the present invention. Figures 9a to 9e are a top view of a building 1 showing a suspension system for a scaffolding system in different positions and arrangements on the roof of the building 1. The suspension systems shown in Figures 9a to 9e are of the continuous kind shown in Figure 8, i.e. the suspension systems on opposing sides of a building are connected, for example by means of a connection member. Figure 9a shows a first phase of work on a building 1, wherein two suspension systems 80 are provide on opposing upper and lower sides of the building 1. In addition, a further two suspension systems 82 are provide at the right side of the building 1, from which a scaffolding unit 20 is suspended. The suspension systems 80 and 82 are of a kind as described above. As indicated in Figure 9a, for safe operation the arrangement is secured to the building at four positions 84. Once work on the right hand exterior face of the building 1 is complete, the suspension systems 82 for gaining access to the right hand exterior face of the building 1 are removed and two scaffolding units 20 are suspended from the opposing suspension systems 80, as shown in Figure 9b. No change in the suspension system securing positions is required. Thereafter, the suspension systems 80 are moved to positions on the building 1 as shown in Figures 9c and 9d to enable work to begin on the third and fourth phases of work. Finally, two additional suspension systems 82 are included in the arrangement to gain access to the left hand exterior face of the building for the fifth phase of work, as shown in Figure 9e. As is clearly demonstrated by the method of use shown in Figures 9a to 9e, a scaffolding system according to the present invention affords a considerable increase in flexibility of access to the exterior of a building. Furthermore, such an 13 arrangement requires a minimum number of points of attachment and changes in points of attachment to the building. In contrast, a conventional access system of the kind shown in Figure 1 would require theinstallation of an access rail around the perimeter of the roof of the building. Thus, a significant increase in system complexity and cost would be incurred.

Figures 10a to 10d are a representation of a fourth method of use of a scaffolding system according to the present invention. Figures 10a to 10d are a top view of a building 1 showing a suspension system for a scaffolding system in different positions and arrangements on the roof of the building 1. The suspension systems shown in Figures 10a to 10d are of the non-continuous kind shown in Figure 7, i.e. the suspension systems on opposing sides of a building are not connected. Figure 10a shows a first phase of work on a building 1, wherein two suspension systems 90 are provide on opposing upper and lower sides of the building 1. In addition, a farther two suspension systems 92 are provide at the right side of the building 1, from which a scaffolding unit 20 is suspended. The suspension systems 90 and 92 are of a kind as described above. As indicated in Figure 10a, for safe operation the arrangement is secured to the building at four positions 94. Once work on the right hand exterior face of the building 1 is complete, the suspension systems 92 for gai g access to the right hand exterior face of the building 1 are removed and two scaffolding units 20 are suspended from the opposing suspension systems 90, as shown in Figure 10b. No change in the suspension system securing positions is required. Thereafter, the suspension systems 90 are moved to positions on the building 1 to enable work to begin on the third and fourth phases of work. The arrangement for the third phase of work is shown in Figure 10c. Finally, two additional suspension systems 92 are included in the arrangement to gain access to the left hand exterior face of the building for the fifth phase of work, as shown in Figure 10d. As is clearly demonstrated by the method of use shown in Figures 10a to 10d, a scaffolding system according to the present invention affords a considerable increase in flexibility of access to the exterior of a building. Furthermore, such an arrangement requires a minimum number of points of attachment and changes in points of attachment to the building. In contrast, as stated above a conventional access system of the kind shown in Figure 1 would require the installation of an access rail around the perimeter of the roof of the building.

14 In the scaffolding units described herein, which are of the type comprising rear restraint wires, it is preferred that the position of the wires can be changed either manually or automatically. The movement of the position of the rear restraint wires is accomplished by moving the restraint guides provided on the scaffolding unit.

Another embodiment of the present invention is illustrated in Figures lla and llb. Figure lla shows a top view of a building 1 and an arrangement for suspending two scaffolding units on opposing vertical exterior faces or elevations of the building. A first scaffolding unit is suspended by means of a first cable 100 and a second scaffolding unit is suspended by means of a second cable 102. As shown in Figure llb, the first cable 100 and the second cable 102 are disposed over the vertical exterior surfaces and roof of the building 1. One end of the first cable 100 is attached to the ground on a first elevation of the building and the first scaffolding unit is suspended adjacent the second elevation by means of the first cable 100, which second elevation opposes the first elevation. The scaffolding unit moves in the vertical direction on the elevation of the building by means of a climber motor provided on the scaffolding unit. The climber motor grips the cable and causes the scaffolding to move relative to the cable. It is preferred that the end of the first cable 100 which is ad acent the second elevation of the building, i.e. the elevation at which j the first scaffolding unit is suspended, is attached to the ground. Either end of the first cable 100 can be attached at or towards the bottom of the building instead being attached to the ground. One end of the second cable 102 is attached to the ground on the second elevation of the building and the second scaffolding unit is suspended adjacent the first elevation by means of the second cable 102. It is preferred that the end of the second cable 102 which is adjacent the first elevation of the building, i.e. the elevation at which the second scaffolding unit is suspended, is attached to the ground. In addition, it is preferred that the portion of the first cable which is adjacent the first elevation of the building is coupled to the second scaffolding unit to act as a restraining wire for the second scaffolding unit. Furthermore, it is preferred that the portion of the second cablewhich is adjacent the second elevation of the building is coupled to the first scaffolding unit to act as a restraining wire for the first scaffolding unit. The cables are coupled to their respective scaffolding is units by restraint guides of a type discussed above. Thus, two scaffolding units are suspended and restrained on opposing elevations of a building by means of a two cable arrangement. Each of the two cables acts as a suspension cable for one scaffolding unit and as a restraining wire for the other scaffolding unit. In a preferred embodiment the arrangement comprises four cables, with two of the four cable functioning as suspension cables and each of the two cables attached to either end of a scaffolding unit. The preferred four wire arrangement provides for maximum stability of the scaffolding units and maximum safety of the operators. Typically, the cables 100 and 102 have a cross-section of 16 mm.

As shown in Figure 11 a, a length of cable 104 can be provided on a cable 102. The length of cable 104 is referred to as a spur. The spur 104 is provided on the main cable at around roof height and is secured to the roof or an upper portion of the building. It is preferred that a spur 104 is provided on each of the cables in a scaffolding system. The presence of a spur 104 on the cables provides for a back-up means of suspension in the event that the main cable 100, 102 fails.

Figure 12 is a representation of the anchor points that are used to secure the cables 100 and 102 of Figures l la and l lb to the ground. Figure 12 shows the ground 110, e.g. the pavement, at the bottom of a building 1. Two anchor points 112 and 114 are shown in Figure 12 at ground level 110. An anchor point can extend above the level of the ground 110, as illustrated by the left-hand anchor point 112 of Figure 12. Alternatively, an anchor point can be embedded in the ground 110, as illustrated by the right-hand anchor point 114 of Figure 12. It is preferred that an embedded anchor point 114 is provided with a cover. The anchor points can either be embedded in the ground or bolted to the ground. It is preferred that the cables 100 and 102 are attached to the anchor points by means of a bolt and hole arrangement. Alternatively, the cables 100 and 102 can be attached to the anchor points by means of cement or some other high strength adhesive. It is preferred that four anchor points are provided for every 10 meter distance along the side of a building.

For safe and reliable operation of the scaffolding system illustrated in Figures 11 a and 1 lb it is preferred that the cables 100 and 102 are supported on the roof of the building. A 16 representation of an appropriate means of roof support is shown in Figure 13. The building 1 of Figure 13 comprises a concrete or steel parapet 120, which extends around the outer periphery of the roof of the building. An attachment member 122 is disposed on the roof of the building 1 behind the parapet 120, to provide a means of attachment for the roof cable supports. The attachment member 122 can be of any appropriate shape or material. However, it is preferred that the attachment member is a steel tube. The attachment member 122 can be cast into the roof of the building. Alternatively, the attachment member can be welded to the parapet 120, if the parapet is made of steel.

Where a steel column head is accessible on a roof an alternative means of attaching an attachment member can be used. Figure 14 is a representation of a steel column 126, which is accessible at roof level. An attachment member 124 is welded to the top of the steel column 126 to provide an attachment point for the roof cable supports. Alternatively, concrete column heads might be accessible on the roof of a building. An attachment member can be cast into the top of the concrete column head to provide an attachment point for the roof cable supports. Usually, concrete and steel columns are provided in a building at a separation of 4.5 to 9 meters.

An alternative to the arrangements shown in Figures 13 and 14 exists where a steel or concrete ring beam is present on a building. Figure 15 shows a steel or concrete ring beam 126. The attachment members 124 are provided on the steel or cement ring beam by an appropriate means, e.g. by casting in or by welding.

The roof cable support attachment members 122, 124 are permanently installed on a building during the construction of the building. Alternatively, the members 122, 124 can be installed after completion of the building, and can, if it is required, be removed after the work is complete.

Figure 16 is an illustration of a typical roof cable support arrangement. As shown in Figure 16, an extension element 128 is secured to the attachment member 124. Where the attachment member is a hollow cylinder and the extension element is a cylinder of an appropriate diameter the extension member can be slidably engaged with the attachment 17 member. The function of the extension element 128 is to raise the roof cable support above the level of the roof of the building. The roof cable support is provided on the extension element. The roof cable support comprises two sets of pulleys. As is shown in Figure 16, a first set of pulleys 130 is provided at the top of the roof cable support. A second set of pulleys 132 is provided at a position extending beyond the outer periphery of the building. As can be seen from Figure 16, the two sets of pulleys 130 and 132 support and guide the cables of the scaffolding system. Referring to Figure 16, a first cable 100 is attached to a first scaffolding unit at one end. The first cable 100 extends up the first elevation of the building, runs over the inner-most pulley of the second set of pulleys 132 and runs in between the pulleys of the first set of pulleys 130. The first cable 100 then extends across the roof of the building to a second roof cable support arrangement, which is similar to that shown in Figure 16. At the second roof cable support arrangement the first cable 100 passes over the upper-most pulley of the first set of pulleys 130 and over the outer-most pulley of the second set of pulleys 132. The first cable 100 extends down the second elevation of the building and is attached to the ground. The second cable 102 is coupled to the first scaffolding unit to perform a restraining function as described above. The second cable 102 extends from the first scaffolding unit up the first elevation of the building, over the outer-most pulley of the second set of pulleys 132 and passes over the upper-most pulley of the first set of pulleys 130, as shown in Figure 16. The second cable then extends across the roof of the building to the second roof cable support arrangement where the second cable follows the path taken by the first cable 100 in the first roof cable support arrangement shown in Figure 16. The second cable 102 extends down the second elevation of the building and is attached to a second scaffolding unit. The pulleys of the first set of pulleys 130 and the second set of pulleys 132 can be positioned so that the first cable 100 and the second cable 102 are in line with each other in the vertical direction. Alternatively, the pulleys of the first and second set of pulleys 130 and 132 can be positioned so that the first and second cables 100 and 102 are separated in the horizontal direction.

A preferred embodiment of the roof cable support arrangement is shown in plan view in Figure 17. A scaffolding unit 20 is represented as being suspended from a building 1.

18 The scaffolding unit 20 is suspended from cables provided over the roof of the building as described above, which cables are not shown in Figure 17. As shown in Figure 17, the arrangement comprises two extension elements 128 and two roof cable support arrangements of a type described above with reference to Figure 16. Each of the two roof cable support arrangements comprises two brackets 134 and 136, on which are provided pulleys for supporting and guiding the cables of the scaffolding system. Alternatively, each of the two roof cable support arrangements can comprises one bracket where appropriate. It is preferred that the brackets 134 and 136 have a gallows type structure, i.e. each bracket comprises a brace member, which brace member is attached at one end to the distal end of the bracket and attached at its other end to the extension element 128. The pulleys of the arrangement of Figure 17 comprise pulleys with a horizontal axis of rotation, of the kind shown in Figure 16. The horizontal axis pulleys are represented in Figure 17 by the dark rectangles disposed towards the distal end of the brackets 134 and 136. It is preferred that the arrangement comprises pulleys with a vertical axis of rotation 138 provided on the upper portion of the brackets 134 and 136, as shown in Figure 17. The vertical axis pulleys 138 can be used as an aid in guiding the cables 100 and 102 of the scaffolding system. Alternatively, the vertical axis pulleys 138 can be used to guide a cable 140 which extends along the line of the exterior face of the building, as shown in Figure 17. The cable 140 functions as a restraint wire. It is preferred that the cable 140 is attached at one end to the ground below the scaffolding unit, extends up the exterior face of the building, runs through the roof cable support arrangements of Figure 17, extends down the exterior face of the building, and is secured at its other end to the ground.

The aforegoing description has been given by way of example only and it will be appreciated by a person skilled in the art that modifications can be made without departing from the scope of the present invention.

19

Claims

1. A scaffolding system comprising: a suspension cable; at least one restraint wire comprising a portion for securing to a structure; a scaffolding unit for suspension from a structure by means of the suspension cable, said scaffolding unit comprising at least one restraint guide for said restraint wire; and said at least one restraint wire is for controlling the position of said scaffolding unit in a direction perpendicular to a direction of suspension.

2. A scaffolding system as claimed in claim 1, wherein said portion of said at least one restraint wire is for securing towards or at the top of the structure above said scaffolding unit.

3. A scaffolding system as claimed in claim 1 or claim 2, wherein a second portion of said at least one restraint wire is for securing below said scaffolding unit.

4. A scaffolding system as claimed in claim 3, wherein said second portion of said at least one restraint wire is for securing towards or at the bottom of a structure.

5. A scaffolding system as claimed in claim 3, wherein said second portion of said at least one restraint wire is for securing to a weight.

6. A scaffolding system as claimed in any one of claims 1 to 5, wherein: said at least one restraint guide is provided on a side of said scaffolding unit, which side is for disposal substantially in line with and facing away from a surface of a structure, and said at least one restraint wire is a rear restraint wire for control of the separation between said scaffolding unit and the surface of a structure.

7. A scaffolding system as claimed in any one of claims 1 to 5, wherein:

said at least one restraint guide is provided on a side of said scaffolding unit, Which side is for disposal substantially perpendicular to a surface of a structure, and said at least one restraint wire is a side restraint wire for control of the position of the scaffolding unit substantially in the plane of the surface of the structure.

8. A scaffolding system as claimed in any one of claims 1 to 5, wherein:

said at least one restraint guide comprises a restraint guide provided on each of a first and a second side of said scaffolding unit and two restraint guides provided on a third side of said scaffolding unit; 1 the first and second sides of said scaffolding unit are opposing sides for disposal substantially perpendicular to a surface of a structure; the.third side of said scaffolding unit is for disposal substantially in line with and facing away from a surface of a structure; and said at least one restraint wire comprises two side restraint wires and two rear restraint wires for control of the position of the scaffolding unit in directions perpendicular to a direction of suspension.

9. A scaffolding system as claimed in any one of claims 1 to 8, wherein said at least one restraint guide comprises at least one roller or wheel.

10. A scaffolding system as claimed in any one of claims 1 to 9, wherein the position of said at least one restraint guide on the scaffolding unit is moveable manually or automatically.

11. A scaffolding system comprising a first anchor point for disposal towards or at the bottom of a first elevation of a building; a scaffolding unit for suspension from or adjacent a second elevation of a building opposite said first elevation; and 21 a first cable for disposal on a building and for coupling to said suspended scaffolding unit, said cable comprising a first portion at or towards one end of the cable for securing to said first anchor point.

12. A scaffolding system as claimed in claim 11, further comprising a second anchor point for disposal towards or at the bottom of a second elevation of a building, and wherein the cable comprises a second portion at or towards another end of the cable for securing to said second anchor point.

13. A scaffolding system as claimed in claim 11 or claim 12, further comprising: a second anchor point for disposal towards or at the bottom of a second elevation of a building opposite the first elevation, a second scaffolding unit for suspension from or adjacent said first elevation; a second cable for disposal on a building and for coupling to said second suspended scaffolding unit, said second cable comprising a first portion at or towards o ne end of the cable for securing to said second anchor point.

14. A scaffolding system as claimed in claim 13, wherein: the first cable comprises a second portion at or towards another end of the cable for securing to the second anchor point; and the second cable comprises a second portion at or towards another end of the cable for securing to the first anchor point.

15. A scaffolding system as claimed in claim 13 or claim 14, wherein: the first cable is for coupling to the second scaffolding unit to thereby control the position of the second scaffolding unit in a direction perpendicular to its direction of suspension; and the second cable is for coupling to the first scaffolding unit to thereby control the position of the first scaffolding unit in a direction perpendicular to its direction of suspension.

22

16. A scaffolding system as claimed in any one of claims 11 to. 15, further comprising a spur from the cable for attachment at or towards the roof of a building, said spur being between the first portion of the cable and a portion of the cable for coupling to a suspended scaffolding unit.

17. A scaffolding system as claimed in claim 16 when dependant on claim 15, wherein: spurs are provided on the first cable for attachment at or towards the top of the first elevation and at or towards the top of the second elevation of a building; and spurs are provided on the second cable for attachment at or towards the top of the first elevation and at or towards the top of the second elevation of a building.,

18. A scaffolding system as claimed in any one of claims 11 to 17, further comprising a roof anchor point for disposal at or towards the roof of a building and a support member for coupling with said roof anchor point.

19. A scaffolding system as claimed in claim 18, wherein said roof anchor point is cast, welded or affixed by concrete to the building.

20. A scaffolding system as claimed in claim 18 or claim 19, wherein said support member comprises rollers to guide the first and/or second cable.

21. A scaffolding system as claimed in any one of claims 11 to 20, wherein said anchor point is for permanent disposal on or adjacent a building and said scaffolding unit is for temporary suspension from or adjacent a building.

22. A scaffolding system comprising: at least one anchor point for permanent disposal towards or on the top of a building; at least one suspension system for removeably coupling with said at least one anchor point; and 23 a scaffolding unit for temporary suspension adjacent a building from said at least one suspension system.

23. A scaffolding system as claimed in claim 22, wherein said scaffolding unit is a multi-stage scaffolding unit comprising a plurality of stages corresponding to a plurality of levels of a building.

24. A scaffolding system as claimed in claim 22 or claim 23, wherein said at least one anchor point is for welding or embedment towards or on the top of a building.

25. A scaffolding system as claimed in any one of claims 22 to 24, wherein said at least one anchor point is for disposal in a floor slab or an up-stand provided on the building.

26. A scaffolding system as claimed in any one of claims 22 to 25, wherein said suspension system comprises a balancing element, which balancing element is for applying a force to balance a force applied by the weight of said scaffolding unit.

27. A scaffolding system as claimed in claim 26, wherein said balancing element comprises a connection member for mechanically linking to a second suspension system.

28. A scaffolding system as claimed in claim 27, wherein said connection member comprises a truss for strengthening said connection member.

29. A scaffolding system as claimed in claim 26, wherein said balancing element comprises a member for securing to a building or the ground.

30. A scaffolding system as claimed in claim 26, wherein said balancing element comprises a weight for disposal on or towards the roof of a building or on the ground.

24

31. A scaffolding system as claimed in any one of claims 22 to 30, wherein said suspension system comprises a suspension member for suspending said scaffolding unit adjacent a vertical face of a building.

32. A scaffolding system for temporary disposal on a building comprising: at least one cable; at least one member for removeable disposal on a building and for supporting of said at least one cable;. a scaffolding unit for suspension from or adjacent a building; at least one suspension element provided on said scaffolding unit for attachment to a portion of said at least one cable.

33. A scaffolding system as claimed in claim 32, further comprising a balancing element, said balancing element for applying a force to balance a force applied by the weight of said scaffolding unit..

34. A scaffolding system as claimed in claim 33, wherein said balancing element comprises a connection member for linking to a second scaffolding system.

35. A scaffolding system as claimed in claim 34, wherein said connection member comprises a truss for strengthening said connection member.

36. A scaffolding system as claimed in claim 33, wherein said balancing element is provided at a second portion on said at least one cable and is for securing to a building or the ground.

37. A scaffolding system as claimed in claim 33, wherein said balancing element comprises a weight for disposal on or towards the roof of a building or on the ground.

38. A scaffolding system as claimed in any one of claims 32 to 37, wherein said at least one member comprises a suspension member for suspending said scaffolding unit by means of said at least one cable adjacent a vertical face of a building.

39. A scaffolding system as claimed in any one of the preceding claims, wherein the scaffolding unit comprises a suspension element for securing to a suspension cable, said suspension element comprising a truss for strengthening the suspension element.

1

40. A scaffolding system as claimed in any one of the preceding claims, wherein the scaffolding unit comprises a material handling bar. 1

41. A scaffolding system as claimed in any one of the preceding claims, wherein the scaffolding unit comprises a work platform, and said work platform comprises a truss for strengthening the work platform.

42. A scaffolding system substantially as described herein and with reference to any one of figures 1 to 17