EP0413510A1

EP0413510A1 - Apparatus for use in fitting roofing sheets

Info

Publication number: EP0413510A1
Application number: EP90308760A
Authority: EP
Inventors: Nigel Peter West
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-08-14
Filing date: 1990-08-09
Publication date: 1991-02-20
Also published as: GB8918508D0

Abstract

A work platform (10) for use in fitting roof sheets to the beams of a building can be slid on integral rollers (18) along the beams. A cantilevered guard frame (32) extends from the work platform to the edge of the last fitted row of roof sheets so as to prevent a workman falling through the gap intended to receive the next row of roof sheets. Additional protection is provided in the form of a safety grid (100,104) which is positioned over a roof light and remains, thereafter, a permanent roof component.

Description

This invention relates to the fitting of roofing or similar sheets on buildings or other beamed structures.
In a typical construction, roof sheets deposited in stacks on the top of a building are manouvered into place and secured manually with bolts or similar fittings. The sheets extend between two or more adjacent roof girders or beams and it will be understood that there is a significant risk of injury or death if a workman should fall between the roof girders whilst manhandling or fitting the sheets. To avoid the necessity of workmen balancing on roof girders, there have previously been provided work platforms which, when correctly assembled in situ, can slide transversely across the roof girders as the fitting of roofing sheets progresses. Such platforms are of some assistance but still leave the workmen at risk of falling through the gap that is to receive the next sheet or row of sheets. This gap is of course defined between the leading edge of the already fitted sheets and the platform itself, Existing designs of work platforms suffer from the additional disadvantage that they require assembly on the roof in a configuration to fit the spacing of roof girders.
It is one object of the present invention to provide improved apparatus for use in the fitting of roofing or similar sheets which offers greater safety for workmen.
Accordingly, the present invention consists in one aspect in apparatus for use in the fitting of roofing or similar sheets to beamed structures, comprising an elongate work platform having guide means cooperable with beams of the structure to enable the platform to be moved over the structure as the fitting of sheets progresses, wherein there is provided a guard frame extending transversely as a cantilever from the work platform, the guard frame providing openings enabling fixing of roof sheets by a workman through the guard frame whilst preventing a workman falling, and being adapted in use to overlie the leading edge of previously roof sheets whilst covering that area of the structure which is to receive the next sheet or row of sheets.
Advantageously the free edge of the guard frame is spaced a sufficient vertical distance above the previously fitted roof sheets to enable supplies of roof sheets to be drawn into the spaced beneath the guard frame.
Preferably, said guide means comprising a plurality of roller assemblies, each slidable along the length of the platform.
It is a further object of the present invention to provide an improved method of fitting roofing or similar sheets to beam structures.
Accordingly, the present invention consists in another aspect in a method of fitting roofing or similar sheets to beamed structures comprising the steps of providing a supply of roofing sheets; establishing a temporary guard structure over an area to receive the next row of roofing sheets; drawing sheets into position beneath said guard structure; manually securing the sheets, acting through said guard structure, and displacing the guard structure transversely to cover the area to receive the next succeeding row of roof sheets.
It will be appreciated that the present invention considerably reduces the risks to workmen in fitting roofing sheets. In particular, the area which is to receive the next row of roofing sheets, that is to say the gap between the leading edge of the already fitted sheets and the work platform is, by the present invention, protected by a guard frame.
In those roof structures including roof lights, there is a further danger that workmen - either during construction or in subsequent roof maintenance - may fall or tread accidentally on a roof light incapable of bearing their weight.
Accordingly, the method according to the present invention preferably includes the further step of securing over each roof light a permanent safety grid capable of bearing the weight of a workman whilst reducing light transmission to a negligible extent.
In still a further aspect, the present invention comprises a safety grid adapted to be secured to roof beams over a roof light, the safety grid being capable of bearing the weight of a workman whilst reducing light transmission through the roof light to a negligible extent.
This invention will now be described by way of example with reference to the accompanying drawings in which:-

Figure 1 is an exploded perspective view showing apparatus according to the present invention;
Figure 2 is a perspective view to an enlarged scale illustrating part of the apparatus of Figure 1;
Figure 3 is a section through the part shown in Figure 2;
Figure 4 is a sketch illustrating the interconnection of apparatus according to the present invention;
Figure 5 is a perspective view illustrating the method of fitting roof sheets according to the present invention, further illustrating an additional feature of the present invention and;
Figure 6 is a perspective view illustrating a modification to said further feature of the invention.

Referring to Figure 1, the apparatus shown generally at 10 comprises a board 12 of heavy gauge plywood or similar material. The parallel long edges of the board 12 are each provided with a timber edge strip 14 with one of these edge strips having bolted to it a steel track 16. In a manner which will be described in more detail later, this steel track 16 provides a mounting for five roller assemblies 18 intended to engage the individual roof girders.
The upper surface of the board 12 is provided, a short distance inwards of the track 16, with a row of anchorage points 20. These together provide a mounting for a main hand rail 22 having legs 24 and upper and lower rails 26 and 28 respectively. Locking pins (not shown) are provided for locking the hand rail in position relative to the anchorage points 20 so that the main hand rail 22 is rigid in position but yet readily demountable.
At the opposite long edge of the board 12 there is provided a further row of anchorage points 30 which together provide a mounting for a guard frame 32. This frame comprises four parallel rails 34 extending substantially the length of the board 12 with three cross members 36. The innermost rail 34 is provided with five orthogonal legs 38 which are received by the anchorage points 30. The guard frame 32 is readily demountable in the same fashion as the main handrail 22.
At either or both ends of the board 12 there are provided end hand rails 40 with only one such hand rail being shown in Figure 1. Hand rail 40 is generally L shaped with clips 42 to engage both the main hand rail 22 and the guard frame 32. Near one end of the board 12, the end members 14 are provided with sockets 44 which cooperate with hooks 46 provided on an end piece 48. The opposite end of the board 12 has hooks (not shown) similar to the hooks 46 and capable of engaging sockets on a modified end piece or, if it is intended to join two or more boards together, the sockets 44 on an adjacent board.
Referring now to Figures 2 and 3, the roller assemblies 18 will be described in more detail. The track 16 is of C-section with inwardly turned flanges 50 adjacent the track opening. Each roller assembly comprises a low friction bush 52 which is dimensioned to be a close sliding fit within the track 16, there being at the front of the bush 52 a dovetail slot 54 to accommodate the inwardly turned flanges 50. The bush 52 provides a mounting for a U-shaped roller support 56 with the parallel legs of this support being received in the bush 52 at the base of the dovetail slot 54.
The roller support 56 carries in its mid-portion a rotatable, dumbell shaped roller 58. The length of this roller is sufficient to accommodate a wide range of standard roof girder dimensions. At each end of the roller 58 there is provided a clamp 60 of L-shaped section. Each clamp 60 is biased inwardly of the roller support 56 by a compression spring 62 acting against a stop 64. The clamps 60 are rotatable through 180^o to take up either of the positions shown in Figure 2. In use, depending upon the orientation of the roof girder (as shown in faint outline at 66) one or other of the clamps 60 will engage beneath the top flange of the girder.
In a typical arrangement, two or more boards will be joined lengthwise with hooks 70 provided on one board engaging the sockets 44 provided at the corresponding end of the adjacent board. This is illustrated in Figure 4. To improve rigidity, a tongue 72 rigidly secured beneath the end of one board, engages beneath the corresponding end of the adjoining board.
The method by which the described apparatus is used to assist the fitting of roof sheets will now be described and for this purpose reference will be made additionally to Figure 5. The apparatus according to this invention, delivered for example by crane to the top of the building, rests on the roof girders 66. By sliding each roller assembly along the track 16, proper alignment can readily be assured between the rollers and girders. The appropriate clamp 60 of each roller assembly is engaged with the girder by first drawing it outward against the action of the compression spring 62, rotating the clamp through 180^o and then releasing. With each of the roller assemblies 18 engaged and locked to a corresponding girder, the board is safely held in position. It will be observed from Figure 3 that with the end members 14 engaging the roof girders, each roller 58 is being spaced a short distance above the surface of the roof girder. Transverse movement of the board is thus resisted through the considerable friction of the end members 14 on the roof girders. In order to move the board into position, the edge spaced from the track 16 is lifted, for example through lifting of the guard frame 32. In this way, the rollers 58 are brought into engagement with the corresponding girders and the end members 14 lifted sufficiently to enable the board to be slid transversely along the length of the girders
If necessary, a number of boards are joined lengthwise in the manner described above. The opposite ends of the assembled board lengths will then be provided with end members and end hand rails.
Taking the position, as shown in Figure 5, in which roofing sheets have been fitted up to a leading edge 80, the board 12 will be positioned so that the outermost rail 34 of the guard frame 32 overlies the leading edge 80, with a sufficient area of roof space being left between the leading edge and the opposing end rail 14, to receive the next row of roof sheets. From a stack conveniently positioned on top of a previously fitted roof sheet, fresh sheets are drawn into position utilising the vertical gap left between the outer edge of the cantilevered guard frame and the surface of the fitted roof sheets. During this operation workmen are of course prevented from falling between the board 12 and the leading edge 80 by the presence of the guard frame. The aligned roof sheets are then secured in position by workmen leaning through the guard frame 32 from, at their option, either then the board 12 or the previously fitted roof sheets.
The size and number of the rails 34 and cross pieces 36 making up the guard frame 32 are selected so that, in an accident, the weight of a workman can be supported with no risk of him falling through the gaps in the frame. The frame is, nonetheless, sufficiently open to as to offer substantially no impediment to the fitting operation.
In the example illustrated in Figure 5, a double skin of roofing sheets is employed. Beams 82 are secured to the main roof girders over the first layer of roof sheets and, once fitting of the first layer has been completed, the apparatus according to this invention can be used in analoagous fashion to fit the upper layer with the roller assemblies 18 then engaging the beams 82.
When necessary, the main hand rail 22 and the guard frame 32 (together with any end hand rail being used) can readily be demounted and laid flat on the roof to enable a fresh stack of roofing sheets to be drawn over the board 12 to a convenient position for roofing to recommence.
Since the roller assemblies 18 can slide along the length of the board to accomodate different beam or girder spacings, there is no need for the work platform to be assembled in situ and the complete board can simply be transported by crane to the roof top. The period of time for which workmen are operating without the benefit of a functioning work platform is thus considerably reduced, as compared to earlier proposals in which rollers need to be fitted in the correct position, on the roof top. Moreover, the ability of the roller assemblies to slide whilst the platform is being moved to a new position along the roof girders, considerably reduces the risk of jamming should the spacing of adjacent girders vary.
A typical roof construction will incorporate a number of roof lights in the form of relatively thin, translucent sheets each taking the place of a roofing sheet. In fitting of the upper layer of roofing sheets, there would be a risk of a workman falling through such a roof light. Accordingly, the present invention provides in its preferred form a roof light safety grill. As shown in Figure 5, this grill comprises bars 100 which extend between adjacent beams 82 above the roof light 102 with an array of cross pieces 104 secured as appropriate to the bars 100 or the beams 82. Protected in this way, the roof lights do not present any additional risk to the workmen when fitting the second roof skin. Moreover, the grill serves a continuing purpose in the completed roof to protect those working on the roof for maintenance or other purposes. Whilst a workman falling onto the aligned roof light in the upper skin might fracture that upper roof light, he would be saved from falling through the lower roof light by the safety grill.
In the case of a single skin roof, the same protection for those working on a completed roof can be provided by a modified form of safety grill as shown in Figure 6. Here, a square grid is formed of cross pieces 106 with the end cross pieces which are aligned with the underlying roof girders being bolted through the roofing sheets to those girders. In this way, the roof light is protected both during fitting of further roof sheets and during the life of the completed roof.
It will be understood that this invention has been described by way of example only and a variety of modifications are possible without departing from the scope of the invention.

Claims

1. Apparatus for use in the fitting of roofing or similar sheets to beamed structures, comprising an elongate work platform having guide means cooperable with beams of the structure to enable the platform to be moved over the structure as the fitting of sheets progresses, wherein there is provided a guard frame extending transversely as a cantilever from the work platform, the guard frame providing openings enabling fixing of roof sheets by a workman through the guard frame whilst preventing a workman falling, and being adapted in use to overlie the leading edge of previously roof sheets whilst covering that area of the structure which is to receive the next sheet or row of sheets.

2. Apparatus according to Claim 1, wherein the free edge of the guard frame is spaced a sufficient vertical distance above the previously fitted roof sheets to enable supplies of roof sheets to be drawn into the space beneath the guard frame.

3. Apparatus according to Claim 2, wherein the guard frame comprises leg means extending vertically upwards from the work platform and an integral safety grid extending horizontally from said leg means.

4. Apparatus according to any one of the preceding claims, wherein said guide means comprises a plurality of roller assemblies, each slidable along the length of the platform.

5. Apparatus according to Claim 4, wherein said roller assemblies are freely slidable along the length of the platform so as to accomodate variations in beam spacing as the platform is moved over said

6. Apparatus according to any one of the preceding claims, further comprising at a longitudinal edge of the work platform opposing said guard frame, a readily demountable hand rail.

7. A method of fitting roofing or similar sheets to beamed structures, comprising the steps of providing a supply of roofing sheets; establishing a temporary guard structure over an area to receive the next row of roofing sheets; drawing sheets into position beneath said guard structure; manually securing the sheets, acting through said guard structure, and displacing the guard structure transversely to cover the area to receive the next succeeding row of roof sheets.

8. A method according to Claim 7, comprising the further steps of fitting one or more roof lights to said beamed structure and securing over each said roof light a permanent safety grid capable of bearing the weight of a workman whilst reducing light transmission to a negligible extent.

9. A method of fitting roofing or similar sheets to beamed structures, at least some of said sheets being of a translucent material to serve as lights, the method comprising establishing a work platform over the beams of the structure; securing a row of roof sheets to said beams, acting from said work platform, the row including at least one of said lights, securing over said light a permanent safety grid capable of bearing the weight of a workman whilst reducing light transmission to a negligible extent; displacing the work platform along said beams and fitting scceeding rows of sheets which each optionally include a further light.

10 . A safety grid adapted to be secured to roof beams over a roof light, the safety grid being capable of bearing the weight of a workman whilst reducing light transmission through the roof light to a negligible extent.