GB2087967A - Scaffolding tower - Google Patents

Abstract

A multi-stage scaffolding tower comprises sets of two frame elements 10, 12 and a tie bar 14 at each level of the tower arranged in equilateral triangular plan form configuration. Each of the frame elements 10, 12 is in the form of a truss and the parts constituting the various elements of each frame and the tie bar 14 comprise lengths of angle section metal bolted or rivetted together. <IMAGE>

Description

SPECIFICATION A builders scaffolding tower This invention relates to a builders scaffolding tower for use adjacent to building structures whereby persons requiring to work on the structure may gain access thereto at predetermined levels above the ground.

Access towers of varying types are known in the art. For example towers comprising sets of inter-engaging tubular steel frame elements are known wherein the sets of frame elements, when assembled, may be formed into a tower of square or rectangular plan form; diagonal bracing being provided at various levels according to the number of sets of frame elements making up the tower.

It is an object of the present invention to provide an improved construction of tower which is economical to produce and easy to assemble.

In accordance with the invention there is provided a builders scaffolding tower of triangular plan form comprising a pair of horizontally spaced apart first uprights extending vertically over one lift of the tower and defining two corners thereof, at least one member interconnecting said first uprights, a pair of second uprights extending in vertically aligned relation one above the other over said one lift of the tower and defining the third corner thereof, and a pair of vertically spaced apart transoms extending horizontally from each said second upright to an associated said first upright.

The tower may comprise a plurality of lifts thereto one above the other, each said first upright in each lift of the tower being in vertically aligned relation with a similar first upright in the adjacent lift and each pair of said second uprights also being in vertically aligned relation with a similar pair of second uprights in the adjacent lift.

Diagonal bracing may be provided interconnecting the transoms in each pair thereof and further diagonal bracing may be provided interconnecting the pair of said first uprights; also it is preferable that at least one strut interconnects the transoms in each said pair thereof.

The tower is conveniently of equilateral triangular plan form and all of the parts thereof may be formed of elongate angle section metal bolted or riveted together or of tubular metal. The metal may be steel or aluminium.

The interconnecting member may comprise at least one tie bar provided with spigot or socket means at each of its ends for engagement with a said first upright and each said second upright may also be provided with spigot or socket means for engagement with the adjacent said second upright. Alternativety, the interconnecting member may comprise at least one diagonal brace, or a scissor brace, connected between said first uprights.

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 exploded perspective-view of an access tower in accordance with the invention, Figure 2 is a detailed perspective view of a socket means used in the tower, Figure 3 is a diagrammatic view of an alternative embodiment of access tower showing a pre-assembled arrangement thereof prior to final assembly, Figure 4 is a diagrammatic perspective view of the assembled tower of Figure 3, Figure 5 is a diagrammatic view of a further alternative embodiment in pre-assembled condition prior to final assembly, and Figure 6 is a diagrammatic perspective view of the tower of Figure 5.

Referring to Figure 1 of the drawings there is shown a builders scaffolding access tower in accordance with the invention comprising two lifts thereto and a top guard rail assembly. The tower may be used as a direct access support for a workman or a plurality of such towers may support access scaffolding connected between the towers. Each of the lifts of the tower is provided by a set of two frame elements 10, 12 and an interconnecting member in the form of a tie bar 14 and, in this embodiment, all of the parts constituting the frame elements and the tie bars are formed of elongate angle section metal such as steel or aluminium.

Each of the two frame elements in each set is basically identical and comprises a truss. Thus, as showr, the first frame element 10 comprises a first vertically disposable upright or leg 16, a second vertically disposable upright or leg 18 of shorter length than said first leg 16, horizontally disposable transoms 20 connecting the ends of said second leg 1 8 to an end of the first leg 16 and a point intermediate its ends respectively, diagonal bracing 22 connecting the first leg 1 6 to the transoms 20 and a vertically disposable strut 24 inter-connecting the transoms 20 intermediate their ends.All of the parts constituting this frame element are bolted together at their respective points of intersection and it is to be noted that, whereas the transoms 20, the diagonal brace 22 and the vertical strut 24 are of 900 angle section metal, the two legs 1 6 and 18 are of 600 angle section metal.

As illustrated, the diagonal bracing 22 comprises a single element connected between a point adjacent the free end of the first leg 1 6 and the transoms 20. Alternatively the diagonal bracing may comprise two separate bracing elements, a first one of which may connect the lower transom to a point adjacent the free end of the first leg 1 6 and a second one of which may connect the lower transom to the upper transom; the second bracing element being either parallel, or at an angle to, the first bracing element.

The second frame element 1 2 of each set is basically identical with the first and the two elements 10 and 12 are assembleable together to form a lift of the tower with the second leg 1 8 of one frame element disposed above the second leg 1 8 of the other frame element whereby the first legs 16 of the two frame elements extend over the height of the lift and are horizontally spaced from one another.

For ease of erection, the second frame elements 12 are provided with pre-assembled sockets 26, as described in more detail herein, at each of the ends of the second legs 1 8 thereof.

A tie bar 14 also formed of 900 angle section metal, is connectable between the upper ends of the first legs 1 6 to maintain the angular relationship between the two frame elements 10 and 1 2 in each lift. An additional identical tie bar 1 4 is provided to connect together the lower ends of the first legs 1 6 at the base of the tower.

The various interconnections comprise a short length of 600 angle metal adapted to form a socket 26. Thus one such socket connector 26 is pre-assembled, by bolting or welding, to each end of the second leg 1 8 of the second frame element 12 in the set for engagement with the second leg of the first frame element 10 which is thereafter bolted to it. Similarly the two outer ends of the tie bar 14 are provided with short lengths of 600 angle metal each of which is pre-assembled, by bolting or welding to a respective end of the tie bar, the socket means 26 so provided on the tie bar 14 then being bolted to a said first leg 16 of each frame element in the set.

Referring now to Figure 2 of the drawings, there is shown a socket 26 pre-assembled and secured at each end of a tie bar 14. This socket comprises a short length of 600 angle metal, one face of which is made slightly convex to accommodate within it the heads of the bolts used in securing together adjacent frame elements over which the socket overlaps. In the particular construction shown in Figure 2 wherein the socket 26 is pre-assembled on the end of a tie bar 14, a slot is formed intermediate the ends of the socket element and a brace 28 is inserted through the slot and welded in position; the brace 28 then being boltable, or otherwise securable, to the upper face of the tie bar 14.

The socket elements 26 provided at each end of the second leg 1 8 of the second frame elements 12 are of a similar shape to the socket elements shown in Figure 2 except that they are not provided with the slot and brace 28.

Although the various elements 26 described herein are illustrated as sockets fitting around the outside of the various elements which they interconnect, it should be appreciated that such elements 26 may equally well comprise spigots securable to the interior surfaces of the elements which they interconnect.

Thus one lift of the tower is provided by the two frame elements 10 and 12 and tie bar 14 and is of equilateral triangular plan configuration.

As shown in Figure 1 of the drawings there are provided two lifts to the tower and a top guard rail assembly with the lowermost ends of the lower lift being provided with two sets of wheels and a base plate. As shown somewhat diagrammatically in Figure 1 each set of wheels comprises a pair of spaced rollers 30 on a common axle to which is attached a vertically disposable 600 angle section metal support 32 boltable to the lower end of a first leg 1 6 of one frame element 10 and a second leg 1 8 of the other frame element 1 2 respectively.

A square or rectangular base plate 34 having a 600 angle section metal support 36 extending vertically therefrom is bolted to the lower end of the first leg 1 6 of the second frame element 12 whereby, when the complete tower is assembled, it may be readily moved on its wheels by lifting the base plate corner of the assembly off the ground.

The second lift of the tower illustrated is formed in an identical manner to that hereinbefore described with reference to the first lift and is connected vertically above it by the 600 angle section metal socket elements 26 hereinbefore described appropriately bolted to the respective points of abutment between the frame element legs 1 6-1 6 and 18-18 of the first and second lifts.

It will be appreciated that the sockets 26 at the ends of the tie bars 14 are stiffened by the provision of the braces 28. Alternatively, or in addition to these braces 28, an additional diagonal brace 27 may be provided interconnecting the diagonally opposed sockets 26 on the upper and lower tie bars 14: such brace 27 being shown in dotted outline in Figure 1.

At the upper ends of the second lift there is provided a top guard rail assembly comprising a guard frame 38 a guard post 40 and rail 42 and a tie bar 44. The guard frame 38 comprises two vertically disposable legs 46 of 600 angle section metal inter-connected at their upper and lower ends by horizontally disposable rails 48 of 900 angle section metal; the two rails 48 being diagonally braced also by 90 angle section metal elements 50. The guard post 40 comprises a vertical 60 angle section metal element of the same length as the legs 46 of the guard frame whilst the guard rail 42 is a 900 angle section metal element attached to the upper end of the guard post 40.The guard rail assembly is completed by a tie bar 44 having socket elements 26 at each of its ends of the type hereinbefore described and connected respectively between the upper end of the guard post 40 and the upper end of one of the legs 46 of the guard frame 38. The lower end of the guard post 40 and the lower ends of the legs 46 of the guard frame 38 are secured to the upper ends of respective legs of the second lift of the tower by 600 angle section metal connectors 26 of the type hereinbefore described.

Although only two lifts and a guard rail assembly are illustrated in the drawings it will be appreciated that any number of lifts may be provided to the tower compatible with its stabiiity.

Referring again to Figure 1 of the drawings a trapezoidal working platform 58 is provided at the upper level of the uppermost lift of the tower. The working platform 58 which will usually be made of wood, is supported at two of its four sides on the horizontal portions of the angle section metal elements comprising respectively an upper transom 20 of a first frame element 10 and the lower transom 48 of the guard frame 38. A full triangular area to the working platform may be provided by the addition of a small triangular auxiliary platform 60 acting as a trap door access on to the main platform; the auxiliary platform 60 being supported at two of its three sides respectively on the upper transom 20 of a first frame element 10 and the lower transom 48 of the guard frame 38.The corner of the tower assembly at which the auxiliary platform 60 is provided is conveniently the corner at which the tower may be climbed for access on to the platform and, to facilitate climbing, additional horizontal climbing rungs 62 as shown in chain dot outline in Figure 1 may be provided connectable between the second leg 1 8 and diagonal brace 22 of the first frame element 10.

In Figures 3 to 6 of the drawings there is illustrated two alternative embodiments of access tower constructed in accordance with the invention wherein the various parts thereof are formed of tubular metal and wherein certain elements thereof are pre-assembled prior to final erection.

In the embodiment illustrated in Figures 3 and 4 a pre-assembled arrangement comprising one lift to the tower is shown in Figure 3. Considering this arrangement to be in the vertical plane prior to final erection, the pre-assembly comprises a pair of horizontally spaced first uprights 70 extending over a full lift of the tower and defining two corners thereof. Each said first upright 70 has a pair of vertically spaced transoms 72 extending horizontally therefrom; the left hand pair of transoms extending respectively from a point adjacent the upper end of the associated upright 70 and a point intermediate its ends and the right hand pair of transoms extending from a point adjacent the lower end of the associated upright 70 and a point intermediate its ends. The two transoms 72 in each pair thereof are interconnected by a vertically extending strut 74.

The strut 74 is welded at its upper and lower ends to its associated transom 72 and the inner ends of each pair of transoms are welded to the associated said first upright 70. Diagonal bracing 76, as shown in dotted outline, may be provided and welded between the upper and lower transoms 72 in each pair thereof.

A second upright 78, of approximately half the length of each first upright 70, interconnects the outer ends of each pair of transoms 72 and is welded thereto.

The lower end of each first upright 70 is provided with a fixed extension spigot 80 whilst both the upper and lower ends of the second upright 78 on the right hand side of Figure 3 are provided with retractable extension spigots 82.

Tie bars 84 interconnect the first uprights 70 and are connected thereto by means of sleeve sockets 86 whereby the uprights 70, together with their associated pairs of transoms 72 and second upright 78, are each rotatable within respective sockets 86.

Thus to assemble the arrangement shown in Figure 3 into the actual tower shown in Figure 4, the two uprights 70 are rotated within their sockets until the two second uprights 78 are vertically aligned one above the other at which time the retractable upper spigot 82 may be engaged within the lower end of the other second upright 78 to lock the tower into its erected triangular plan form configuration. It will be appreciated that this embodiment illustrated in Figures 3 and 4 may also be utilised to form a multi-lift tower wherein the first uprights 70 in each lift of the tower may be vertically aligned above similar first uprights in an adjacent lift with the fixed lower spigots 80 engaged within the upper ends of the uprights 70 of the adjacent lift.

Similarly each pair of second uprights 78 may be vertically aligned with a similar pair of second uprights in an adjacent lift with the retractable spigot 82 engaged within the upper end of a second upright 78 of the adjacent lift. Although not illustrated herein it will further be appreciated that a tower constructed in accordance with the principles of Figures 3 and 4 may also be provided with appropriate wheels and base together with an upper level guard rail assembly and working platform.

A further alternative embodiment is shown in Figure 5 and 6 wherein life reference numerals refer to like parts described with respect to Figures 3 and 4. Thus the pre-assembled arrangement as illustrated in Figure 5 comprises a pair of horizontally spaced first uprights 70 each of which has an associated pair of transoms 72, a strut 74, diagonal bracing 76 and a second upright 78.

However in this construction each pair of transoms 72 is rotatably mounted upon an associated first upright 70 by means of sleeve sockets 73 whereby the two pairs of transoms 72, and their associated second upright 78, may be rotated about their associated first uprights 70 to bring the second upright 78 into aligned vertical relation with one another for final erection into the triangular plan form configuration of tower illustrated in Figure 6.

In this construction the first uprights 70 are interconnected by fixed tie bars 84 each welded at their ends to an associated upright 70.

Again it will be appreciated that the construction illustrated in Figures 5 and 6 may be assembled into a multi-lift tower together with appropriate wheels, base, guard rails and working platform all substantially as hereinbefore described.

Claims (14)

1. A builders scaffolding tower of triangular plan form comprising a pair of horizontally spaced apart first uprights extending vertically over one lift of the tower and defining two corners thereof, at least one member interconnecting said first uprights, a pair of second uprights extending in vertically aligned relation one above the other over said one lift of the tower and defining the third corner thereof, and a pair of vertically spaced apart transoms extending horizontally from each said second upright to an associated said first upright.

2. A tower as claimed in Claim 1 comprising a plurality of lifts thereto one above the other, each said first upright in each lift of the tower being in vertically aligned relation with a similar first upright in the adjacent lift and each pair of said second uprights also being in vertically aligned relation with a similar pair of second uprights in the adjacent lift.

3. A tower as claimed in either one of Claims 1 or 2 wherein diagonal bracing is provided interconnecting the transoms in each said pair thereof.

4. A tower as claimed in any one of Claims 1 to 3 wherein diagonal bracing is provided interconnecting the pair of said first uprights.

5. A tower as claimed in any one of Claims 1 to 4 wherein at least one strut interconnects the transoms in each said pair thereof.

6. A tower as claimed in any one of Claims 1 to 5 which is of equilateral triangular plan form.

7. A tower as claimed in any one of the preceding claims wherein all of the parts thereof are formed of elongate angle section metal.

8. A tower as claimed in Claim 7 wherein the said parts are bolted or rivetted together.

9. A tower as claimed in any one of Claims 1 to 6 wherein all of the parts thereof are formed of tubular metal.

10. A tower as claimed in any one of the preceding claims wherein each interconnecting member is provided with spigot or socket means at each of its ends for engagement with a said first upright.

11. A tower as claimed in any one of the preceding claims wherein each said second upright is provided with spigot or socket means for engagement with the adjacent said second upright.

12. A tower as claimed in either one of Claims 10 or 11 when linked with Claim 7 wherein each spigot or socket means comprises a length of angle section metal.

1 3. A tower as claimed in Claim 12 wherein the angle section metal comprising the spigot or socket means and the said first and second uprights comprises a channel having a 600 included angle.

14. A tower constructed and arranged substantially as hereinbefore described with reference to and as shown in any of the accompanying drawings.