GB2067508A

GB2067508A - Servicing overhead structures

Info

Publication number: GB2067508A
Application number: GB8001085A
Authority: GB
Original assignee: A Monk and Co Ltd
Current assignee: A Monk and Co Ltd
Priority date: 1980-01-12
Filing date: 1980-01-12
Publication date: 1981-07-30
Also published as: GB2067508B

Abstract

The invention concerns apparatus for servicing overhead structures and, in particular, concerns a traversable overhead working platform 10 equipped with at least one further working platform 50 which is mounted relative to the main platform arrangement via rails or runway beams 44 so as itself to be traversable laterally of the direction of traverse of the main platform arrangement and thus be extendable and retractable to the side of the main platform arrangement. <IMAGE>

Description

SPECIFICATION Servicing overhead structures The invention relates to apparatus for servicing overhead structures.

We have made proposals for and developments of systems for servicing overhead structures using working platforms suspended from and traversable along rails or runway beams spanning several frame members of the structure and usually themselves traversable relative to those frame members. Such systems and apparatus have proved to be highly successful in use, especially by reason of leaving the space below the structure free for normal use while work proceeds from our working platform, and also, usually, by complete stage-wise traversal of the structure by our entire apparatus including its rails or runway beams.

It is, of course, frequently necessary to have working platforms at different heights as many structures to be serviced are arched, pitched or otherwise have parts thereof at different heights. That is advantageously accomplished utilising either a single platform with several stepped deckings at appropriate heights, or by a composite platform arrangement with lower platforms suspended both from rails or runway beams associated with the frame members of the structure and from the next uppermost platform. We have found it to be advantageous for at least some lower platforms to be suspended from rails or runway beams from the next upper platform to to permit a degree of relative movement of the platforms, say with a main top platform longer than subsidiary lower platforms.

However, although our previous arrangements can traverse curved structures by using flexible suspensions, they do require a clear run along the structure to be serviced. That has left localised side regions or galieries of the structure, or even side parts beyond support pillars or the like, to be serviced by fixed scaffolding. It is an object of this invention to overcome such problems.

To this end, we now proposed that a traversable overhead working platform arrangement be further equipped with at least one further working platform that is mounted relative to the main platform arrangement via rails or runway beams so as itselfto be traversable laterally of the direction of traverse of the main platform arrangement and thus be extendable and retractable to the side of the main platform arrangement.

In a preferred embodiment the further platform is secured to at least two rails or runway beams that are coupled at the underside of a main platform to be extendable relative thereto. Advantageously, the couplings are of trolley form with pairs of wheels or rollers embracing flanging of each rail or runway beam to give support both upwardly and downwardly. If desired the further platform itself can run on wheeled or roller trolleys on lower flanging of each rail or runway beam, thereby enabling running of the further platform along its rails or beams independently of extension and retraction of those rails or beams.

One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an elevational view from the end of a platform supporting a side extendable further platform; Figure 2 is a partial side view corresponding to Figure 1; Figure 3 is a plan view showing the support arrangement of Figures 1 and 2; Figure 4 is a plan view of the supporting platform; and Figure 5 shows stages in a sequence of operations during extension.

In the drawings, a working platform 10 is supported from above for traverse in the direction of arrow A after the manner of our systems referred to above. Thus, suspensions may be from trolleys engaged on overhead rails or runway beams spanning at least several frame members or support posi tionsofa structure to be serviced. Those rails or runway beams may themselves also be traversable in the direction of arrow A in other trolleys secured to the said frame members or at said support positions. For a multi-level working platform, or a composite working platform arrangement, the platform 10 will usually be the outermost and lowermost level or component platform. In the latter case one side of the platform 10 may be supported from a higher platform either directly or via rails or runway beams as desired.

The platform 10 is shown as being fabricated in the same manner as disclosed in ourcopending application no. 79/35629 (P778) using beams 12 with upper and lower rails 14 and 16, vertical spacers 18 and diagonal braces 20, preferably of lightweight square section tubing. Flooring panels 22 conveniently comprise wood on bearers 24 extending between the beams 12 and secured end-to-end thereto by top rail saddle brackets 26 also serving to locate ends of beam-to-beam braces 28 extending therefrom to other, bottom rail, saddle brackets 30 also serving in locating ends of bracing 32 between bottom rails of the beams 12.

Our above mentioned application no. 79/35629 also -provides for bracing running at angles across the frame using spacers 18 as anchorages via clamp type couplings. Such bracing is indicated herein by dashed lines 36,38.

The platform 10 is shown as having trolleys 40 secured thereto by shackles 42 to protrude below the underside and support I-section rails 44. The trolleys 40 have upper and lower wheels or rollers to embrace upper flanging of the rails and counter the effects of any bending forces applied thereto. The rails 44 are also shown with four-wheel trolleys 46 running on their lower flanging and supporting a further platform 50 for movement therealong, usually by flexible or intermediately pivotted suspen sions.

We preferto use a minimum number of rails 44 consistent with loading and size of he platform 50.

Such minimisation (only two rails 44 are actually shown) means that the spacing of the rails 44 is best determined by the requirements for platform 10 ratherthan by the positions of beams 12 of the platform 10, which are best determined by consideration of modularity of its own and other platforms' design and construction. Thus, the positions of such means 12 will rarely correspond to the desired positions of the rails 44. Also, the aforesaid beams are of a strength mainly directed at requirements of the platform 10.

Thus, we prefer herein to provide supports for the rail trolleys 40 by way of beams 52 that extend between beams 12 and thus both afford a choice of securement positions therealong for the trolleys 40 and serve in spreading direct loading of beams 12 between at least two thereof.

As shown, the platform 50 is narrow compared with the width of platform 10 and the available extension of the rails 44. In fact, it is conveniently sized for construction from two beams such as 12 and one set of flooring panels such as 22 with appropriate inter-beam bracing and tying. Also, the rails 44 actually exceed the width of the platform 10, as is especially suited to the situation where platform 10 is an outer one or outer part of a composite platform arrangement.

It will also be noted that, for intended working extension in the direction of arrow B, the spacing between rail support beams 52 is closer at the outer or extension side of platform 10 than at the other or inner side. This is satisfactory and economical as forces inherent in cantilevering an extension are obviously less for shorter extensions and greater for longer extensions. lrregularspacingsofthe beams 52 increasing from right to left of Figure 2 are thus proposed and recommended herein.

Prior to extension of the platform 50 neither it nor its support rails 44 will protrude at all to the right or outside of platform 10, though the rails 44 can protrude to the left or inwardly. This allows traversing of the platform 10 without fouling any support pillars or the like. For extension of the platform 50, the rails 44 are first extended by running them through their supporting trolleys. This can be done one rail at a time with the platform 50 held relative to the plat form 10. We preferthat, ator before maximum extension for simple cantilever support of the rails 44 and platform 50, the rails 44 be themselves sup ported in trolleys 60 from a convenient position of the structure to be secured. Thereafter, the rails 44 may be further extended (and, if desired, further supported) to increase the "reach" of the platform 50 from the platform 10. Some stages in this sequence of events are illustrated diagramatically in Figure 5.

Claims

1. Atraversableworking platform arrangement for use in servicing overhead structures equipped with at least one further working platform mounted relative to the main platform arrangement so as itself to be traversable laterally of the direction of traverse of the main platform arrangement and thus be extendable and retractable to the side of the main platform arrangement.

2. Aworking platform arrangement as claimed in claim 1, wherein the further platform is mounted relative to the main platform arrangement via rails or runway beams.

3. Aworking platform arrangement as claimed in claim 2, wherein the further platform is secured to at least two rails or runway beams coupled atthe underside of the main platform to be extendable relative thereto.

4. Aworking platform arrangement as claimed in claim 3, wherein couplings between the rails or beams and the main platform are of trolley form with pairs of wheels or rollers embracing upper flanging of each rail or runway beam to give support both upwardly and downwardly.

5. A working platform arrangement as claimed in claim 4, wherein the further working platform itself can run on wheeled or rollertrolleyson lowerflang- ing of each rail or runway beam.

6. Atraversable working platform arrangement substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.