GB2215374A - Scaffolding - Google Patents

Abstract

A mobile access structure 10 comprises a frame having decking cantilevered outwardly therefrom whereby, for example, operatives may gain access to structural steelwork from a position outboard of a floor area on which the access structure is standing. The frame has two frame elements with uprights 16, 32 interconnected by respective horizontals 18, 34. The two frame elements are interconnected by horizontal braces 26, 30, 36 and two cantilever brackets extend outwardly from two uprights 16 to support decking 56 thereon. Tilting forces imparted to the frame upon loading of the decking 56 are countered by a Kentledge box 60 secured between lower horizontals 18 of the frame elements. The structure 10 is fitted with lockable castor wheels 20 for ready mobility. <IMAGE>

Description

MOBILE ACCESS STRUCTURE This invention relates to an access structure of the type particularly, but not exclusively, intended for use in the construction of multi-storey buildings to enable operatives to obtain access to structural steelwork extending between the floors4 For example, it is often necessary to spray fire-proofing materials onto structural steelwork extending vertically of the building at the perimeters of the floors outwardly of the floor surfaces and, for such treatment, it is necessary for the operatives to be able to spray the entire circumference on the steelwork.This cannot be easily accomplished safely from the inside of the building as the operatives often cannot reach sufficiently far outwardly of the floor surfaces to direct the spraying equipment, which is heavy and cumbersome, to the remotest parts of the steelwork Consequently it has been the practice to spray the steelwork from the outside of the building with the consequential use of exterior scaffold structure erected upwardly from ground level.

It is an object of the present invention to provide an access structure erectable on a floor area which will enable an operative to work from said structure outboard of such floor area. Particularly, but not exclusively, such an access structure finds application in enabling operatives to work outboard of the floor surfaces of a multi-storey building In accordance with the invention there is provided mobile access structure comprising a plurality of upright frame elements arranged in a frame defining a plan area, cantilever support means mounted on said frame supporting decking extending outwardly of said plan area and means associated with the frame for countering tilting forces imparted to the frame upon loading of said decking The cantilever support means conveniently comprises a plurality of cantilever brackets detachably secured to the frame and each of said cantilever brackets conveniently comprises, in use, a horizontal decking support element, a vertical support element extending downwardly of said decking support element from a position adjacent an inboard end thereof and an inclined brace element extending from a position adjacent an outboard end of said decking support element to said vertical support element, and means for securing said bracket to a said frame element Each said cantilever bracket is conveniently securable to an upright member and a horizontal member of a said frame element. Preferably, a plurality of weights are distributed on the frame so as to extend along that side of the frame remote from an opposed side thereof on which said cantilever support means is mounted Alternatively, or additionally, to the use of such a plurality of weights, tilting forces imparted to the frame upon loading of the decking may be countered by the use of screw jack elements and/or ties temporarily connecting the frame to adjacent rigid structure Other features of the invention will become apparent from the following description given herein solely by way of example with reference to the accompanying drawings wherein:: Figure 1 is an isometric view of access structure in accordance with the invention located adjacent the outer edge of a floor of a multi-storey building in course of construction; Figure 2 is another isometric view of the access structure of the invention in course of erection showing details of the mounting of the cantilever brackets to the frame elements of the structure; and Figure 3 is a further isometric view showing a preliminary step in the erection of the access structure The mobile access structure 10 of the invention comprises a pair of opposed frame elements interconnected by braces to form a tower frame having a defined rectangular plan area and wherein cantilever support means is mounted on the frame supporting decking extending outwardly of said plan area As shown in Figure 1, the structure 10 is locatable adjacent the outer edge of a floor 12 of a multi-storey building whereby operatives may utilise the outwardly cantilevered decking to gain access to adjacent steelwork 14.

As can be better seen from Figures 2 and 3, each of two main frame elements comprises a pair of vertically disposable uprights 16 interconnected by equidistantly spaced horizontals 18 connected between the uprights In the particular construction illustrated, five such horizontals 18 interconnect the two uprights 16 of each main frame element The lower end of each upright 16 is provided with a height-adjustable, lockable castor wheel assembly 20 of known construction whereby, when erected, the access structure 10 as a whole may be readily moved to a desired location, levelled and the castor wheels 20 locked to prevent inadvertent movement. The upper ends of the uprights 16 of each of the main frame elements are each provided with a spigot 22 having an inwardly facing lug 24 for inter-engagement with further elements of the structure 10 as described below.

As shown in Figure 3, the two main frame elements are assembled initially by the use of horizontal braces 26 having hook ends and spring loaded retaining pins of known construction Two such horizontal braces 26 are shown fitted in Figure 3 and the plan area of the frame of the structure 10 is thus defined by the lengths of the horizontal braces 26 and the lengths of the horizontals 18 interconnecting the uprights 16 in each main frame element A further step in the erection of the access structure is shown in Figure 2 from which it will be seen that there are provided diagonal braces 28 interconnecting the frame elements and a further horizontal brace 30 at that side of the frame remote from that at which the cantilever support means is to be mounted Such diagonal braces 28 and the additional horizontal brace 30 are also conveniently provided with hook ends and spring loaded retaining pins of known form.

Also in Figure 2 there is shown part of an upper frame constituting a vertical extension to the main frame elements and comprising two opposed minor frame elements each having two uprights 32 interconnected by two horizontals 34 with the lower ends of the uprights 32 being socketed onto the upwardly extending spigots 22 of the uprights 16; the lugs 24 on the spigots 22 being respectively engaged within locating holes in the lower ends of the uprights 32 of the minor frame elements The upper frame extension includes two additional horizontal braces 36 of the same size and of similar construction to the braces 26 and 30 used to interconnect the main frame elements In Figure 2 there are also shown two cantilever brackets comprising the cantilever support means for the decking.Each of said brackets comprises a horizontal decking support element 38, a vertical support element 40 extending downwardly of the horizontal element 38 adjacent an inboard end thereof and an inclined brace element 42 extending from a position adjacent an outboard end of the horizontal element 38 to the vertical element 40. An upwardly projecting spigot 44 is provided at the outboard end of the horizontal element 38 for receiving further guard rail structure as will be described below and as is illustrated in Figure 1.

The inboard end of each horizontal element 38 of each cantilever bracket is provided with a three way connector 46 of the type shown in Figure 2. Such connector comprises three arcuate recesses, two of which are utilised as shown in Figure 2 to secure the inboard end of the horizontal element 38 of each cantilever bracket in engagement with both a respective upright 16 and an adjacent horizontal 18 of a main frame element The lower end of the vertical element 40 of each cantilever bracket is provided with a horizontally disposed member 48 extending towards the adjacent upright 16 of a main frame element and including a channel shaped socket 50 for engagement about said upright 16 for location purposes.

The complete structure 10 is shown in Figure 1 from which it will be seen that vertical guard rail posts 52 are socketed onto the projections 44 of the cantilever brackets The guard rail posts 52 are interconnected by horizontal braces 54 to one another and to the adjacent uprights 32 of the minor frame elements to define an enclosed decking area cantilevered outwardly from the plan area defined by the main frame elements Conventional decking 56 and toe boards 58 are located on and secured to the horizontal elements 38 of the cantilever brackets in known manner.

Tilting forces imparted to the structure 10 upon loading of the decking 56 are countered by the incorporation of a plurality of weights distributed on the frame so as to extend along that side thereof remote from the side on which the cantilevered decking is supported As illustrated, the weights are contained within a Kentledge box 60 extending between the lowermost horizontals 18 of the main frame elements Alternatively, although not illustrated, tilting forces imparted to the frame upon loading of the decking may be countered by the use of screw jack elements and/or ties temporarily connecting the structure to the adjacent rigid floor or ceiling structure of the building.

Conveniently, a ladder is secured to extend from a lower horizontal 18 to an upper horizontal 34 to enable operatives to gain access to the decking 56 As illustrated in Figure 1, retaining scaffold tubing 62 is laced between adjacent vertical elements of structural steelwork 14 to prevent the mobile access structure 10 from being inadvertently run over the edge of the floor 12.

In the particular application shown in Figure 1, it will be appreciated that operatives standing on the cantilevered decking 56 may access the whole perimeter of adjacent vertical structural steelwork 14 for the purposes of, for example, spraying it with fire proofing materials prior to the finishing construction of the building.

Claims (6)

1. Mobile access structure comprising a plurality of upright frame elements arranged in a frame defining a plan area, cantilever support means mounted on said frame supporting decking extending outwardly of said plan area and means associated with the frame for countering tilting forces imparted to the frame upon loading of said decking

2.Mobile access structure as claimed in Claim 1 wherein said cantilever support means comprises a plurality of cantilever brackets detachably secured to said frame

3 Mobile access structure as claimed in Claim 2 wherein each said cantilever bracket comprises, in use, a horizontal decking support element, a vertical support element extending downwardly of said decking support element from a position adjacent an inboard end thereof and an inclined brace element extending from a position adjacent an outboard end of said decking support element to said vertical support element, and means for securing said bracket to a said frame element

4 Mobile access structure as claimed in either one of Claims 2 or 3 wherein each said cantilever bracket is securable to an upright member and a horizontal member of a said frame element

5. Mobile access structure as claimed in any one of the preceding claims wherein a plurality of weights are distributed on the frame so as to extend along that side of the frame remote from an opposed side thereof on which said cantilever support means is mounted.

6. Mobile access structure constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.