AU5063702A - Scaffolding - Google Patents

Description

WO 01/48334 PCT/AUOO/01580 1 SCAFFOLDING FIELD OF THE INVENTION THIS INVENTION relates to improvements in the building industry and is more specifically concerned with a novel form of scaffolding capable of being erected relatively quickly and cheaply alongside the wall of a building. The scaffolding is principally, 5 although not exclusively, for use in the housing industry where construction does not exceed three storeys. STATE OF THE ART Conventional scaffolding uses short steel poles and scaffolding clips which secure the poles together. The poles which provide standards are braced diagonally and ties are 10 used for securing the scaffolding to a building. The erection proceeds by creating work platforms or bays between four vertical standards. The cost of hiring, erecting, and subsequently dismantling the scaffolding is considerable. The scaffold must be erected from the ground-up and working platforms dismantled from the top-down. If work has to be undertaken on the roof of a building only, building standards require that separate 15 edge protection be erected around the perimeter of the roof line or the conventional scaffolding is required to be erected to a gutter height with edge protection being fitted to the work platform and not the roof to protect the workmen on the roof should they slip, and to protect people working around the base of the building from objects sliding off the roof and free-falling to the ground beneath. Additionally, where work is 20 undertaken below the roof-line, scaffolding is used to provide a safe working platform. The traditional way of erecting a safe platform is to provide scaffolding from the ground up, to support the platform. Because of the time and cost involved in using traditional scaffolding systems, safety standards are not universally enforced and the risks involved have been largely accepted in the building industry. Additionally, smaller building 25 allotment sizes and reduced set-back from boundaries has made it difficult to use conventional scaffolding. Compliance with safety standards in the building industry is now being more rigidly enforced than in the past and alternative and new ways of providing safety platforms below the roof-line, and edge protection around the perimeter of a roof-line have been WO 01/48334 PCT/AUOO/01580 2 suggested. One proposal for avoiding ground-up scaffolding is suggested in the published specification No. WO 99/40274 of International Patent Application No. PCT/AU98/00958 which describes a scaffolding assembly suspended from members attached to roof trusses of a building. However the assembly is naturally rather complex to erect requiring 5 many different parts, and also requires bolt or screw holes to be drilled through the roof trusses or top plates. This proposal would appear to suffer from the same disadvantage as conventional scaffolding, namely, a large number of man-hours are necessary to erect the scaffolding and a consequently relatively high overall cost to the builder is involved. Additionally, the assembly relies on lateral supports from or to the building structure and 10 exhibits instability characteristics. The load on the building structure limits the safe working load. THE INVENTION In accordance with the present invention a scaffolding assembly includes: poles for mounting in a line along a wall of a building so that the poles are upright and arranged in a 15 spaced, parallel relationship; a base for supporting the lower end of each pole in its chosen position; supports mountable on the poles at a selected height to enable a horizontal platform to be supported by the poles beside the wall; attachments connectable to the upper end-portions of the poles; foot members temporarily securable to the lower-end portions of respective sloping roof trusses of the building; and, arms extending between 20 the attachments and the foot members for holding the poles upright; in which assembly the foot members have parts for locating the foot member against the upper, lower and side faces of the roof trusses, the parts being so positioned lengthwise of the foot member, and so shaped, that engagement and release of the foot member from the truss are achieved, respectively by twisting the foot member in opposite directions with respect 25 to the longitudinal axis of the truss. The present invention thus provides a new form of scaffolding for use alongside the wall of a building and in which working platforms rest on horizontal bars which are supported at opposite ends by other bars attached to the poles by means of brackets. It may also be designed to allow edge protection above or below the lower perimeter of the roof-line 30 and enables a work platform to be erected and dismantled at different working levels.

WO 01/48334 PCT/AUOO/01580 3 PREFERRED FEATURES OF THE INVENTION Preferably the poles are of square or rectangular cross-section. The foot member may be designed to be also temporarily secured to a horizontal rafter or top plate of the building instead of a sloping roof truss. It may also be equipped with an 5 adjustable component to enable the arm to remain horizontal despite the foot member being at an angle to the horizontal. Suitably the platform supports include the brackets and can be fixed to the poles at chosen positions which enable said other bars to be attached to them by spigot-and socket or other quick-release connections. The brackets may be designed to be fitted to 10 the pole from its end or, alternatively, from the side. A fitting on, through, or under the bracket may then be used to prevent accidental dislodgment of the bracket from its chosen position on the pole. Some of the brackets conveniently have parts which provide respective connections enabling ends of respective platform support bars to be mounted in them and which will allow the bars to project horizontally from the bracket at opposite 15 sides of the pole and opposite to one another. As an alternative, the bars of the platform support may be designed for locating directly on the poles by using means which temporarily attach one to the other. Conveniently some of the brackets have side shelves which enable the ends of a platform plank, extending between neighbouring poles, to be safely held with its upper surface 20 continuous with the upper surfaces of other planks of the platform. In the preferred arrangement the foot member is provided with flat surfaces for clasping the sides of the roof-truss. A part for preventing sliding movement of the member down the truss may also be provided and shaped to bite into the surface of the truss at the lower end of the member. However this is optional. A screw fixture at the heel end 25 portion of the foot member is provided to allow for adjustment where the roof truss is undersized.

WO 01/48334 PCT/AUOO/01580 4 INTRODUCTION TO THE DRAWINGS The invention will now be described in more detail, by way of examples, with reference to the accompanying diagrammatic drawings, in which: IN THE DRAWINGS 5 FIGURE 1 is a diagrammatic perspective view, partly broken away of a section of a scaffolding assembly erected along the side of a wall of a building in a split platform mode; FIGURE 2 shows a scaffolding pole, partly broken away, together with three scaffolding platforms, the upper end of the pole being held to a roof truss by an arm and a 10 connection fixture and the lower end of the pole resting on a jack-adjustable base at ground level, the platforms remote from the building wall being shown at two individually selectable vertical and separately operable positions on the scaffolding pole, hand rails and kick or toe boards being omitted for the sake of clarity; FIGURES 3A, 3B and 3C are respective perspective views, to an enlarged scale, of three 15 different forms of bracket support used in conjunction with the scaffolding pole which is inserted endwise through openings in the three brackets; FIGURE 4 is a diagrammatic perspective view of a different construction of bracket support designed to be applied to the pole from one side and for securing the upper end of the pole, by way of the arm and connection fixture to a roof truss of the building; 20 FIGURE 5 is a perspective view of a foot member used to provide the attachment of the arm to a roof truss; FIGURE 6 is a diagrammatic plan view of the foot member of Figure 5; FIGURE 7 is an end view of the foot member of Figure 5; and, WO 01/48334 PCT/AUOO/01580 5 FIGURE 8 shows how the described embodiment of the invention can be used to support scaffolding on a building having a set-back, upper wall. DESCRIPTION OF PREFERRED EMBODIMENT Figure 1 shows part of a two storey building 1 having a brick side-wall 2 extending up to a 5 sloping roof 3 provided with wooden roof trusses 4. A set of spaced parallel, upright scaffolding poles 5 of square cross-section are arranged spaced from the outside of the wall 2 and are supported at their upper ends by connection fixtures 6 which are connected by angle bars 7 to foot members 8 attached to the lower end-portions of the roof trusses 4 which slope down beyond the upper end of the wall 2. The lower ends of 10 the poles 5 are secured in or on adjustable jacks 9 resting on sole boards 98 and enabling the bottom level of each of the poles 5 to be adjusted, as shown in Figure 2. The poles 5 are hollow and have three different forms of support bracket 10 shown in Figures 3A, 3B and 3C, respectively, which can be moved to respectively different vertical positions along the poles as shown, and then fixed by passing bolts through the poles as 15 shown in Figure 2 or by being clamped in position. These three forms of bracket will now be described in more detail with reference to figures 3A, 3B and 3C respectively. In each of these Figures the bracket 10 basically comprises a steel section 11 having a square, cross-section opening passing through it and through which the pole 5 is inserted. In the case of the brackets of Figures 3A and 3B, two parallel sides of the section 11 each 20 have welded to it one end of a steel box 12 the sides of which are open. In the case of the bracket shown in Figure 3C a steel U-shaped channel 120 is welded by its intermediate web to each of one pair of opposite sides of the section 11. The bracket 10 shown in Figure 3A has a pair of rectangular boxes 13, 14 which open respectively upwardly and horizontally, and are respectively welded into openings in the 25 box 12. A channel plate 15 providing a horizontal shelf 90 for supporting one end of a foot plank extending between two neighbouring poles 5, is welded to the channel section 11 and the two boxes 12, and provides a robust attachment of the boxes to the section WO 01/48334 PCT/AUOO/01580 6 11. One or more holes 16 permit locking bolts (not shown) to be passed through the section 11 and through a pair of registering holes in the pole 5 at vertically spaced positions at which the bracket 10A is to be located on the pole. An anchor hole 91 is also provided in the shelf 90 to fix one end of a supported plank to it. 5 The bracket 10 shown in Figure 3B is similarly constructed to the bracket 10A except that the vertical box 13 is replaced by a second horizontal box 14 which is axially aligned with the first horizontal box 14, as illustrated. In the bracket of Figure 3C, the sides of the U-section 120 have a pair of aligned openings 17 enabling a locking bolt (not shown) to be passed through them. An angle stop 18 is welded to each side of the box 11 at a 10 position spaced beneath each of the U-sections120. Returning to Figure 2, this shows, in diagrammatic outline only, the three different forms of brackets 10 attached at different chosen vertically-spaced positions on the pole 5. The lowermost bracket 10, which is shown in Figure 3, has located in its U-sections 120 the vertical lower end-portions of V-shaped platform support bars 170 which slope 15 upwards and then horizontally as shown to provide a horizontal plank-support bar 20. The lower vertical ends of the support bars rest on the angle stops 18. The bar 170 may be made in one piece as shown, or it may comprise two straight bars fixed into a connection piece (not shown) attached to the outer ends of the horizontal support bars 20. The other ends of the bars 20 are socketed into respective horizontal aligned boxes 14 of 20 the next bracket 10 above. This is constructed as shown in Figure 3B. The horizontal bars 20 associated with a line of poles 5 each support two horizontal planks 21 as shown in Figure 2 and which extend side-by-side to provide a platform on which workmen can stand when working on the building. The inverted channel plates 15 on the brackets 10 shown in Figure 3A and 3B are arranged so that their shelves 90 support the opposite 25 ends of further planks 21 placed between the pairs of planks 21 on each bar 20 so that a platform is formed with a level surface of five planks width, the mid-plank extending between each pair of poles 5. In the arrangement shown in the lower part of Figure 2 the brackets 10 supports a wide platform extending between opposite sides of the pole 5. However, as shown in the central part of Figure 2, by using a longer sloping v-shaped 30 support bar 19 in place of the support bar 170 remote from the wall 2, a split level WO 01/48334 PCT/AUOO/01580 7 platform is formed with one part at a higher level than the other part. In this configuration, the shelves 90 on the brackets 10, constructed as shown in Figures 3A and 3B, support the opposite ends of further planks extending between the poles 5 so that, when providing a split platform each level of the split platform comprises three planks 5 which have coplanar upper surfaces and the planks of respective platforms which extend between the poles at different levels overlapping one another vertically. Stanchion posts 23 of different lengths are fitted at their lower ends into sockets 29 at the end of the arms 20 and the bar 7, and in the box 13 of the bracket of Figure 3A to provide protection for a workman. The stanchion posts 23 have carriers 24 for 10 supporting horizontal rails (Figure 1) and further carriers 124 for supporting toe or kick boards (Figure 1) arranged on edge and extending between the stanchions 23. The upper end-portion of the pole 5 is positioned by the connecting fixture 6 of H-shape providing two horizontally spaced vertical sleeves 151 and 152 of square cross-section. The sleeve 151 is a sliding fit on the pole 5 and has internally-threaded lateral openings 15 153 on two adjacent sides enabling locking bolts to be screwed through them to engage the pole 5 and thus hold the fixture 6 in a chosen vertical position on the pole. A horizontal bar 154 interconnects the sleeves 151 and 152, and the latter sleeve 152 is a sliding fit on the lower portion of the upper stanchion 23 which has a stepped spigot at its lower end to engage in the socket 29 formed in the upright limb of an angle arm 160 20 which also provides a horizontal bar 7. The upper end-portion of the pole 5 may also be positioned by the collar bracket 6 shown in Figure 4. This is a robust collar of square cross-section and has one side 30 hinged at 31 to allow it to be opened so that the pole 5 can be fitted into the bracket 6 from one side. The Figure shows the side 30 in its open position. The hinged side 30 can be 25 locked in its closed position by a bolt 133 passing through aligned rings 130 so that the bracket 6 cannot be opened and dislodged from the pole 5. A bar 7 is welded at one end to the collar bracket 6 and a trapezium-shaped gusset plate (not shown) provides a robust connection between them. Holes 134 provided in the sides of the collar bracket 6 WO 01/48334 PCT/AUOO/01580 8 enable locking bolts (not shown) to be passed through them and through registering holes in the poles 5. The foot member 8, shown in figures 5, 6 and 7, secures the bar 7 to one of the roof trusses 4 and is of channel shape. It provides a flat sole 32 which rests on the upper 5 face of the roof truss 4. The foot member 8 has a toe end-portion 33 having a vertical lug plate 34 welded to one side. An angle plate 39 provides a horizontal limb 29 extending beneath the roof truss 4 and an upright limb outside the lug plate 24. A slot 35 in the upright limb receives a bolt 27 and enables the wing nut 36 to be tightened to clamp the position of the angle plate 39. An adjustment screw 28 at the toe end 10 portion 33 of the foot member 8, can be tightened in order to enhance the grip of the foot member 8 on the truss 4 if of non-standard cross-section. The foot member 8 is provided nearer its heel 40 and on its side opposite the lug plate 34, with a small parallel plate 49 positioned to lie against the opposite side of the truss 4 to the plate 34. The truss is thus effectively clasped between the plate 49, horizontal 15 limb 29 of the angle plate 39, plate 34 and the sole 32 of the foot member 8. The foot member can be mounted in position on the truss 4, and freed from its mounted position, by twisting it in respectively opposite directions with respect to the truss longitudinal axis. An arcuate set of four holes 44 shown in Figure 5 and centred on a pivot pin 42, enables 20 the angle made by the arm bar 7 to be varied with respect to the sole 32. This is achieved by turning the bar 7 about the horizontal pivot pin 42 in the foot member 8. The holes 44 are pre-set to enable arm bar 7 to remain horizontal when foot member 8 is located on trusses with different roof pitch angles. A locking pin 43 is inserted into one of the arc of holes 44 so that the angle between the bar 7 and the sole 32 of the foot 25 member 31 can be varied and then maintained. A pair of arcuate aligned slots 47 concentric with the arc of holes 44 and formed in respective sides of the foot member 8, enable an intermediate setting of the angle between the bar 7 and the sole 32 to be achieved in the event that the roof pitch does WO 01/48334 PCT/AUOO/01580 9 not have a standard pitch angle to which the holes 44 have respectively been pre-set. This is achieved by passing the arm bar 7 through a block (not shown) having two aligned guide trunnions which pass through the respective slots 47. An adjustable and lockable upright bolt (not shown) passes through a threaded opening in the block and bears on the 5 upper surface of the sole of the foot member 8. By turning the bolt, the block and thus the arm 7 can be moved to a chosen angular position about the pivot pin 42 with respect to the sole 32 of the foot member 8. METHOD OF USE OF PREFERRED EMBODIMENT The assembly described above is erected and used as follows: 10 The poles 5 providing the support for the scaffolding are placed along the side of the wall 2 to be worked on. Normally they will stand about one metre from the wall and will be spaced from one another by about two metres. Each foot member 8 is placed on the lower end-portion of a respective roof-truss 4 to which a corresponding pole 5 is to be attached, and is so arranged that the horizontal limb 29 of the angle plate 39 lies flush 15 against the lower face of the truss 4. The winged nut 36 is then tightened and the free end of the arm bar 7 is moved downwardly until the sole 32 of the foot member 8 lies flush against the top face of the truss. Arm bar 7 is located at the desired angular position by selecting the appropriate hole 44 for the bolt 43. This ensures the socket 29 and its stanchion 23 are maintained vertical 20 in readiness for attachment of the H-shaped fixture 6 which completes the connection to the top end-portion of the pole 5. Each of the brackets 10 is fitted over one end of the pole and moved to its desired position at which it can be fixed by pins passing through the holes 16. The lower ends of the poles 5 are next located on their respective sole boards 98 and their upper end 25 portions, which up to this time have been resting against the eaves of the building and after having the fixture 6 attached, are moved to upright positions and the sleeves 152 encircling lower portions of the upper stanchions 23 which are then fitted into their respective sockets 129. The double sleeve fixture 6 is now connected between the pole WO 01/48334 PCT/AUOO/01580 10 5 and the foot member 8, by way of the stanchion 23 and the arm bar 7 so that the poles are held in their upright positions at both ends. The parts of the scaffolding platforms identified by the numerical references 170, 19 and 20, and the planks 21 are erected as previously described. Any load carried by the poles 5 5 exerts a downwards force on them, and thus by leverage applied by fixtures 6 and arm bars 7 to the heel ends 40 of the members 8, retains the foot members 8 in their respective positions on the roof trusses 4. MODIFICATION OF PREFERRED EMBODIMENT Figure 8 shows how scaffolding assembly poles 5 can be used on a building having an 10 upper wall 61 which is set back in relation to a lower wall 62. Each wall has associated roof trusses 4. Parts of the scaffolding assembly which are identical to those already described carry the same reference numerals. To avoid unnecessary repetition, these will not be again described. The poles 5 are arranged in spaced parallel relationship alongside the upper wall 61 as 15 shown, and their upper ends are each held to a chosen roof truss 4 of the upper roof, by a bracket 6, an arm bar 7 and a foot member 8, as has already been described. However, in place of the jacks 9, the lower ends of the poles 5 are socketed in cups held by z shaped blocks150 which are temporarily attached to respective trusses 4. If the trusses at the two levels in the building are not vertically aligned, a beam (not shown) can be 20 placed between two foot members 8, and parallel to wall 61, and the cups can be moved from the blocks150 to chosen positions along the beam until located directly beneath the desired position for the lower end of the associated pole 5. Other modifications to the above described scaffolding assembly may be made. For example instead of fixing the brackets to the poles by transverse pins threaded through 25 holes in the poles and the brackets, the brackets 10 may be provided individually with camming mechanisms (not shown) formed by rotatable cams mounted on shafts carried in bayonet slots formed in parallel plates extending from the brackets. Rotating the cams forces them against the poles in a direction which increases their force of engagement WO 01/48334 PCT/AUOO/01580 1 1 with the poles, with increasing weight on the bracket 10 produced by additional loading of the platform assembly it supports. This technique avoids any slight weakening of the poles 5 by providing them with holes. In a further modification all of the brackets 10 are openable so that they can be mounted 5 in position on the poles without having to thread the poles through them. In the preferred assembly the plates 34 and 49 on alternate foot members are identically positioned on the right and left of the foot members respectively, whereas the remaining foot members 8 have the plates 34 and 49 respectively positioned on the left and right of the foot members. The two variations of foot member 8 are mounted in alternation 10 on successive roof trusses 4. In this way the upper end of the scaffolding is equally braced against possible inclination in either direction in the common vertical plane containing the poles. Although the use of the foot member 8 with sloping roof trusses 4 has been illustrated in the accompanying drawings, the foot member 8 can also be used in conjunction with the 15 end-portion of a horizontal roof beam to provide a temporary anchorage for the upper end-portion of the pole 5. Finally it should be observed that neither of the wing nuts 28 and 36 are strictly necessary for mounting the foot member 8 on a roof truss 4. If the cross-sectional shape of the roof trusses was standard, the plates 34 and 39 could be provided by a 20 single angle plate. The merit of the arrangement illustrated is that it enables the foot member to clasp the four sides of a roof truss firmly, even when the truss dimensions are not standard, and still to be twisted between its truss-engaged and truss-free positions.

Claims (10)

1. A scaffolding assembly which includes: poles for mounting in a line along a wall of a building so that the poles are upright and arranged in a spaced, parallel relationship; a base for supporting the lower end of each pole in its chosen position; supports mountable 5 on the poles at a selected height to enable a horizontal platform to be supported by the poles beside the wall; attachments connectable to the upper end-portions of the poles; foot members temporarily securable to the lower end-portions of respective sloping roof trusses of the building; and, arms extending between the attachments and the foot members and for holding the poles upright; in which assembly the foot members have 10 parts for locating against the upper, lower and side faces of the roof trusses, the parts being so positioned lengthwise of the foot member, and so shaped, that engagement and release of the foot member from the truss are achieved, respectively, by twisting the foot member in opposite directions with respect to the longitudinal axis of the truss.

2. An assembly as set forth in claim 1, in which the poles are of square or rectangular 15 cross-section.

3. An assembly as set forth in claim 1 or claim 2, in which said parts of the foot member provide flat surfaces between which the roof-truss is clasped when the foot member is in its truss-engaged position.

4. An assembly set forth in claim 1, claim 2 or claim 3, in which the platform 20 supports include brackets for fixing to the poles at chosen positions and which enable platform-support bars to be attached to them by spigot-and-socket connections.

5. An assembly as set forth in claim 4, in which the brackets are designed to be fitted to the poles from one side and means associated with each bracket retain it in its chosen position on the pole. 25

6. An assembly as set forth in claim 4 or in claim 5, in which each bracket provides open-sided boxes for locating ends of platform support bars. WO 01/48334 PCT/AUOO/01580 13

7. An assembly as set forth in any one of claims 4, 5 or 6, in which shelves are provided at opposite sides of a bracket, each shelf being able to support one end portion of a plank extending horizontally between two similar brackets on neighbouring poles.

8. An assembly as claimed in claim 7, including attachment holes in the shelves for 5 receiving anchoring elements which secure the plank end-portions to the shelves.

9. An assembly as claimed in any one of the preceding claims, in which each pole is provided with an arrangement of brackets for supporting opposite ends of a horizontal platform support bar, and the planks of a platform are laid side-by-side on at least two such support bars with their upper faces co-planar.

10 10. An assembly as claimed in any one of the preceding claims, including an H-shaped fixture having two vertical sleeves which are respective sliding fits on the upper end of a pole and a stanchion connected to one of the front members.