GB2506965B

GB2506965B - Roofing edge fall arrest apparatus

Info

Publication number: GB2506965B
Application number: GB1313953.0A
Authority: GB
Inventors: Harrison John; Boyd Simon; Cox Stewart
Original assignee: John Reid & Sons Strucsteel Ltd
Current assignee: John Reid & Sons Strucsteel Ltd
Priority date: 2012-08-10
Filing date: 2013-08-05
Publication date: 2019-08-14
Anticipated expiration: 2033-08-05
Also published as: GB2506965A; GB201313953D0; GB201214416D0

Description

ROOFING EDGE FALL ARREST APPARATUS

The present invention relates to a roofing edge fall arrest apparatus.

For safety reasons, fall arrest arrangements need to be provided in manysituations, to arrest the fall of a worker accidentally falling from a construction.

The use of netting for this purpose is described at the beginning of thedescription below with reference to the accompanying drawings. It is simple but haslimitations.

The object of the present invention is to provide an improved roofing edge fallarrest apparatus.

According to the invention there is provided a roofing edge fall arrestapparatus for use in laying roofing liner or roofing sheets on purlins, the apparatuscomprising: • fall arrest panels arrangeable between purlins, • a beam arrangeable to cross over a plurality of purlins, the panels beingfastened to the beam as a fall arrest structure, • at least one support for supporting the structure on at least some of the purlins,the supports being set in from ends of the fall arrest panels, supporting them ina cantilevered manner, and • means for locating the structure on the purlins.

Usually the supports will be provided in pairs, the two supports of each pairbeing spaced transversely of the length of the beam.

Whilst we can envisaged that the supports could be slides; we prefer toprovide them as rolling elements, in particular rollers. The rollers could be journalledon the beam to act on the purlins to support the structure. Alternatively they could bejournalled on respective fall arrest panels. However in the preferred embodiment,they are journalled between respective pairs of panels for acting on purlins between the pairs. Whilst the rollers could be provided at a spacing different from the width ofthe beam, they are conveniently provided at least substantially at this width.

Where rolling element supports are provided, we normally provide means forbraking them and/or the structure per se against un-intentioned movement along thepurlins. The braking means could be by rope or wires. Equally the locating meanscould be slides but they are preferably rolling elements.

The panels as such could comprise an edge frame with netting or otherlightweight fall arrest elements spanning within the frame. However, in the preferredembodiment, the panels are of steel members, typically box section, within a steelwork frame. Such heavier panels provide the apparatus with stability andcounterbalance capability in use.

The beam is conveniently a steel work truss, comparatively stiff within itsplane, but yet flexible over its length to enable it to follow any curvature of the roof.Alternatively the beam could be stiff over its length, particularly for use with flatroofs.

To help understanding of the invention, a specific embodiment thereof willnow be described by way of example and with reference to the accompanyingdrawings, in which:

Figure 1 is a perspective view of a steel frame building being roofed andprovided with fall arrest apparatus of the invention;

Figure 2 is a perspective view of on a larger scale of fall apparatus laid outprior to installation on the roof;

Figure 3 is an exploded view of fall arrest panels and an interconnecting trussof the apparatus of Figure 2;

Figure 4 is similar view on a larger scale of the two fall arrest panels and theirrollers;

Figure 5 is a similar view of the corresponding end of the truss and its brake;and

Figure 6 is a similar view of the components shown in Figures 4 and 5assembled together.

Referring first to Figure 1 of the drawings, it is a safety requirement forroofing of a steel frame building 1 with roofing sheets 2 that a fall arrest system beprovided for roofers working at the edge 3 of the sheets to reduce the risk of injury ina fall. Normally this is provided by means of netting. However netting is often notconvenient in particular since a space, of the order of 2 metres, must be provided forfall to be arrested. This is not always practical.

In accordance with the invention, roofing edge fall arrest apparatus 11 issupported on purlins 4 of the building, the purlins being frame members extendinglongitudinally of the building and arranged for support of the roofing sheets 2, whichare fixed to the purlins by the roofers. The apparatus is movable along the purlins asthe roofing sheets are laid. For fall arrest it has between each pair of purlins a fallarrest panel 12 of box section steel tube, typically of 30x30mm square. Typically,each panel has from eight to twelve longitudinals 14 of some 4.5m in length. More orless longitudinals of a length to suit the width of the roofing sheets being used can beprovided. The longitudinals have end members 15 welded across their ends.Centrally, set at 0.5m centres, two 50x50mm square cross tubes 16 are welded on topof the longitudinals, at right angles to them. Short longitudinals 17 are welded ontothe ends of the cross tubes. Small lengths of box 18 are welded across the ends of theshort longitudinals down to the end regular longitudinals 141,142. These smalllengths have roller axles 19 connected to them, which axles both interconnectadjacent fall arrest panels and carry rollers 20, which allow the fall arrest apparatus tobe moved along the purlins.

Above the arrangement of fall arrest panels, a truss beam 21 extends,providing more substantially interconnection of the panels than the axles 19. Thetruss is comprised of 50x50mm box section and has two chords 22, cross members 23and triangulation members 24. The truss is thus stiff in bending in the direction of thelongitudinals of the panels, but relatively flexible in deflection out of its plane,enabling it to conform to arching of the roof, when the purlins are arranged for this.The fall arrest panels are clamped to the truss beam by pairs of bolts 25 extendingbetween clamp plates 26, crossing above the chords 22 and below the cross tubes 16.To support the chords and cross tubes against deformation by the clamps short pieces 27 of 3 0x3 Omm box are welded intermittently to the cross tubes between the shortlongitudinals.

To locate the fall arrest panels, and the entire apparatus, from sliding down theroof, in the direction of the truss, across the purlins, the end ones 142 of the regularlongitudinals, which are the lower ones in use, in each fall arrest panel are cut awaycentrally between the cross members 23. In the space provided, a bogie is arranged ineach panel. The bogie comprises a pair of wheels 28 journalled between a pair ofbogie plates 29. Centrally from the next-in regular longitudinal 143 extends a bogiesupport stub 30 centrally pivoted to the bogie plates.

The rollers 20 and the bogie wheels 28 allow the entire apparatus to be pushedalong the purlins manually. Brakes 31 are provided at each end of the truss, actingbetween end ones of the panels and their neighbours. The brakes have arms 32pivoted to the chord on the side remote from the sheet laying side. The arms haveactuating levers 33 telescopically and pivotally arranged in the arms. Thearrangement being such that the levers are normally pivoted back over the arms, butcan be pivoted forwards and telescoped into the arms, whereby the arms can be liftedagainst the torque of springs (not shown as such) provided at the pivots 34. Brakepads 35 in the form of elastomeric pads backed by steel plates are connected to thearms by links 36. Lifting of the brakes at both ends of the truss allow the fall arreststructure to be moved forwards.

For initial deployment of the structure onto the roof purlins by crane, the trussis provided with eyes 37.

Normally across the span of a large roof several fall arrest structures will beused.

In use, they are first set up at one end of the roof to be clad. It will be notedthat the fall arrest panels are set below the top of the purlins, with the rollers beingabove the longitudinals of the panels. The first width of roof sheeting is laid andfastened to the purlins, over the top of the fall arrest panels. For the next sheets, thebrakes are released and the fall arrest structure is advanced one sheet width. This would be inhibited if the fall arrest panels were interconnected between their endmembers 15 over the purlins, i.e. their ends remote from the trusses. However theneed for this is obviated by the configuration of the apparatus. The next sheets arelaid and the process is repeated across the roof. Before the last line of sheets aresecured, the fall arrest apparatus to lifted off the roof, by crane.

In the event of a roofer falling over the edge of the sheeting, either he will landon a portion of a fall arrest panel extending from the truss towards the sheeting or, ifthere is sheeting already installed over this portion of the panel, he will land on thepanel in the region of the truss. In the latter case, the truss and the panel will bestraightforwardly supported by the rollers at the end of the panel, and will support thefaller. In the former case, the faller will fall on a cantilevered section of the panel.Because of its construction, it has considerable mass itself. The tipping point isspaced from the centre of the panel by half the separation of the rollers on the purlins.Thus the faller’s fall is counterbalanced in accordance with the distance from therollers at which his centre of gravity comes to act and the restoring moment of thecentre of gravity of the panel acting at the half separation. We size the panel to givesufficient counterbalance in this respect. Beyond this, each panel, except end oneshas two other panels joined to it by the roller axles. Their centres of gravitycontribute to the counterbalancing, as does the truss. This latter provides more rigidinter-panel connection than the roller axles and thus more assured counterbalancingand feeling of security and rigidity in the event of a fall.

The invention is not intended to be restricted to the details of the abovedescribed embodiment. For instance, the fall arrest panels can be covered withnetting to catch to catch tools and fastenings. The double wheel bogies can bereplaced by single location wheels journalled at the end of the bogies support stub.The rollers and/or location wheels or at least selected ones of them can be providedwith brakes as opposed to the provision of separate brakes.

Claims

CLAIMS:

1. A roofing edge fall arrest apparatus for use in laying roofing liner or roofingsheets on purlins, the apparatus comprising: • fall arrest panels arrangeable between purlins, • a beam arrangeable to cross over a plurality of purlins, the panels beingfastened to the beam as a fall arrest structure, • at least one support for supporting the structure on at least some of thepurlins, the support being set in from ends of the fall arrest panels,supporting them in a cantilevered manner, and • means for locating the structure on the purlins.

2. A roofing edge fall arrest apparatus as claimed in claim 1, wherein the supportsare provided in pairs, the two supports of each pair being spaced transversely of thelength of the beam.

3. A roofing edge fall arrest apparatus as claimed in claim 1 or claim 2, wherein thesupports are slides.

4. A roofing edge fall arrest apparatus as claimed in claim 1 or claim 2, wherein thesupports are rollers.

5. A roofing edge fall arrest apparatus as claimed in claim 4, wherein the rollers arejournalled on the beam to act on the purlins to support the structure.

6. A roofing edge fall arrest apparatus as claimed in claim 4, wherein the rollers arejournalled on respective fall arrest panels.

7. A roofing edge fall arrest apparatus as claimed in claim 4, wherein the rollers arejournalled between respective pairs of panels for acting on purlins between the pairs.

8. A roofing edge fall arrest apparatus as claimed in any one of claims 4 to 7,wherein the rollers are spaced at substantially the width of the beam.

9. A roofing edge fall arrest apparatus as claimed in any one of claim 4 to 8, furtherincluding means for braking the rollers and/or structure per se against un-intentionedmovement along the purlins.

10. A roofing edge fall arrest apparatus as claimed in claim 9, wherein the brakingmeans is rope or wires.

11. A roofing edge fall arrest apparatus as claimed in any preceding claim, whereinthe locating means are slides.

12. A roofing edge fall arrest apparatus as claimed in any one of claims 1 to 10,wherein the locating means are rolling elements.

13. A roofing edge fall arrest apparatus as claimed in any preceding claim, whereinthe panels as such comprise an edge frame with netting or other lightweight fall arrestelements spanning within the frame.

14. A roofing edge fall arrest apparatus as claimed in any one of claims 1 to 12,wherein the panels are of steel members, typically box section, within a steel workframe.

15. A roofing edge fall arrest apparatus as claimed in any preceding claim, whereinthe beam is a steel work truss.

16. A roofing edge fall arrest apparatus as claimed in claim 15, wherein the truss iscomparatively stiff within its plane, but yet flexible over its length to enable it tofollow any curvature of the roof.