GB2070120A - Collapsible builders' stage for use on steps - Google Patents

Abstract

A collapsible scaffolding assembly comprises, in use, an inclined bottom framework (26) supported on a flight of stairs (12) by legs (20, 30). A horizontal framework (34) is pivoted (at 36) to the bottom framework (26) and is supported in fixed relation thereto by a third framework (41). The horizontal framework (34) constitutes or supports a man-supporting surface (14). Conveniently the third framework (41) is hingedly connected to the horizontal framework (34) and anchored by means of hook-form anchor means (23) to the bottom framework (26). It is preferred that the assembly can be folded substantially flat for ease of transport. <IMAGE>

Description

SPECIFICATION Collapsible builders' stage for use on steps The present invention relates to a scaffolding assembly and in particular to a collapsible scaffolding assembly for erection and use on a flight of stairs or other steps to facilitate working on an adjacent wall or ceiling area.

Copending British Patent Application 41259/77 discloses and claims a collapsible buidlers' stage for erection and use on a pitched roof or at a window opening or a building, the stage comprising a first part and second and third parts hingedly connected to the first part, attachment means for engaging an exposed horizontal edge surface of the building, and locking means arranged to abut with a hook-form anchor means on the second part when the stage is suspended for use with the three parts orientated relative to one another so as to have one of the three parts providing, or adapted to support, a man-supporting surface, the abutment of the locking means with the anchor means being effective to prevent relative motion between the three parts when the man-supporting surface is under load.

According to the present invention, a collapsible scaffolding assembly for erection and use on a flight of steps comprises first and second parts hingedly connected together, a third part operable to prevent relative motion between the first and second parts, and two step-engaging leg means each for supporting the assembly on a respective one of two steps in the flight of steps, the third part being operative when the assembly is supported on the flight of step by said stepengaging means to prevent relative motion between the first and second parts with the first part inclined substantially horizontally to provide or support a man-supporting surface and the second part inclined to lie closelv adjacent to the steps spanned by the assembly.

Preferably, the load-supporting length of at least one of the two leg means is adjustable to vary the inclination of the second part relative to the flight of steps.

Additionally, or alternatively, at least one of the leg means may be pivotally mounted relative to the second part to enable the step-engaging end of that leg means to engage different regions of the engaged step.

The third part conveniently comprises a strut means hingedly connected with the first part and adapted to engage with co-operating hook-form anchor means on the second part.

Conveniently, when the anchor means is present, a first one of the two leg means supports the assembly at or near the anchor means, and the second leg means supports the assembly at or near the pivotal connection between the first and second parts. The first leg means may, for example, form part of, or be secured to, the anchor means.

The position of the anchor means is preferably adjustable along the second part to enable the third part to operate at different chosen relative orientations between the first and second parts, and in a preferred mode of operation, the position of the anchor means along the second part is chosen so that the third part is vertical or substantially vertical (i.e. within 50 of the vertical).

The second part may, if desired, be calibrated to indicate the required position of the anchor means for a range of different orientations between the first and seconds parts.

Conveniently the three parts comprise longitudinal frame members joined together as three pivotally interconnected frameworks. The longitudinal members may, for example, be made of aluminium or a light alloy.

When the assembly is not in use it can preferably be folded substantially flat for ease of transport to and from the site.

In preferred embodiments of the invention, the or a man-supporting surface may also be provided or supported at a second location positioned above the one it will occupy when the mansupporting surface is provided or supported by the first part of the assembly.

Conveniently, in this case, the man-supporting surface is supported at the second location by an upward extension of the third part and by a fourth part which shares the pivotal connection between the first and second parts.

The man-supporting surface at the second location may, for example, comprise or engage strut means interconnecting the third and fourth parts to provide a rigid structure.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawing in which: Figure 1 shows a perspective view of a collapsible scaffolding assembly in place on a flight of stairs; Figure 2 shows a perspective view of the same assembly in its fully collapsed state; and Figure 3 shows a side view of a clinometer being used to determine the correct setting of the scaffolding assembly in Figure 1.

Referring first to Figure 1, a collapsible scaffolding assembly 10 in accordance with the present invention is shown in position on a flight of stairs 12 though, for clarity, the man-supporting platform 14 has been shown displaced from support members 1 5 to 18 of an upper platformsupport 19.

At its lower end, assembly 10 is supported on the stairs by leg members 20 which are rigidly secured to a cross member 21 interconnecting two hook-form anchors 23. These anchors are clamped on a bottom framework 26 which, in this embodiment, provides the so-cailed second part referred to earlier in the statements of invention.

At its upper end, the framework 26 carries collar members 28 through which pass upper leg members 30. The load-supporting length of these upper leg members can be varied at will by sliding them through collars 28, e.g. from the positions illustrated in Figure 2 to those illustrated in Figure 1. Once satisfactorily positioned, leg members 30 are locked in place by a pin or bolt (not shown) passing through aligned apertures 32 in members 28 and 30.

The so-called first part of the assembly is provided in this embodiment by another framework 34 which shares a common pivotal connection 36 with framework 26 and with two swivelling puncheons 38 interconnected by members 1 8 of the support 19. In this embodiment, puncheons 38 provide the so-called fourth part of the assembly.

At the other end of framework 34, clamps 39 pivotally clamp framework 34 to the uprights 40 of another framework 41. Framework 41 in this embodiment provides the so-called third part of assembly 10.

At their lower ends uprights are interconnected by a locking bar 42 abutting with the hook-form anchors 23. The upper regions of the uprights are interconnected by cross member 1 5.

The assembly 10 will normally be carded to the site in the fully-collapsed position shown in Figure 2 (with upper framework 1 5 to 1 8 absent). Prior to assembly, the slope of the flight of stairs is measured by placing the bottom edge of a clinometer 42 along the stairs as shown in Figure 3, and then moving the pivoted segment 44 until the spirit level 46 indicates the top edge of the segment to be horizontal. Further details of the clinometer and its operation may be had by reference to copending Application 41258/77.

The reading ("5" in the case illustrated) of the segment pointer on the clinometer scale then indicates the correct setting for the anchors 23 along framework 26 and for clamps 39 along uprights 40 if the platform 14 is to be supported in a substantially horizontal position over the stairs 12.

Once the assembly has been correctly set in this way, it is positioned on the stairs 12 with leg members 20, 30 engaging appropriate stairs of the flight as shown. The assembly is then manually expanded so that locking bar 42 can engage in the anchors 23 to lock the assembly against unintentional collapse.

Finally the platform 14 is put in place on support framework 34 and work on the adjacent wall or ceiling area can be done.

If desired one or more of the frame members 15 to 18 shown in Figure 1 can also be secured in place so as to act as a safety rail in which case one or both of the puncheons 38 may be raised as appropriate. If a higher working area is required, e.g. later on in the work, then all of members 1 5 to 1 8 must of course be present to support platform 14 at the second location as indicated in Figure 1.

Once again of course, additional safety rails (not shown) can be fitted if desired.

It is to be noted that the vertical height of platform 14 can be adjusted without dismantling support 19 simply by slackening off the supporting clamps and forcing members 1 5 and 17 upwards along their vertical supports. Any temporary change in inclination of members 1 6 and 1 8 during this adjustment process is allowed by their pivotal mounting on cross members 1 5, 1 7. Once at the desired new position, the clamps are retightened and work can proceed as before.

If following assembly of platform support 19, it subsequently becomes desirable again to support the platform on the first framework 34, then, once again it is not necessary to dismantle support 19.

All that is required is to remove the clamp connections to puncheons 38 and then swing members 1 6, 18 about cross members 1 5 so that they hang down freely on the downstairs side of uprights 40.

To dismantle the assembly for removal from the site, it is first necessary to remove platform 14 and support 1 9. Next locking bar 42 is displaced upwardly to free it from anchors 23 and the assembly can now be returned to the position shown in Figure 2. It will of course be appreciated that the pivotal nature of the clamps connecting framework 34 to uprights 40 allows this connection to be maintained irrespective of whether the assembly is in its collapsed or its extended state.

Claims (14)

1. A collapsible scaffolding assembly for erection and use on a flight of steps comprises first and second parts hingedly connected together, a third part operable to prevent relative motion between the first and second parts, and two step-engaging leg means each for supporting the assembly on a respective one of two steps in the flight of steps, the third part being operative when the assembly is supported on the flight of steps by said step-engaging means to prevent relative motion between the first and second parts with the first part inclined substantially horizontally to provide or support a mansupporting surface and the second part inclined to lie closely adjacent to the steps spanned by the assembly.

2. An assembly as claimed in Claim 1 wherein the load-supporting length of at least one of the two leg means is adjustable to vary the inclination of the second part relative to the flight of steps.

3. An assembly as claimed in Claim 1 or Claim 2 wherein at least one of the leg means is pivotally mounted relative to the second part to enable the step-engaging end of that leg means to engage different regions of the engaged step.

4. An assembly as claimed in any one of the preceding claims wherein the third part comprises a strut means hingedly connected with the first part and adapted to engage with co-operating hook-form anchor means on the second part.

5. An assembly as claimed in Claim 4 wherein a first one of the two leg means supports the assembly at or near the anchor means, and the second leg means supports the assembly at or near the pivotal connection between the first and second parts.

6. An assembly as claimed in Claim'5 wherein the first leg means form part of, or is secure to, the anchor means.

7. An assembly as claimed in any one of Claims 4 to 6 wherein the position of the anchor means is adjustable along the second part to enable the third part to operate at different chosen relative orientations between the first and second parts.

8. An assembly as claimed in Claim 7 wherein, in use, the position of the anchor means along the second part is chosen so that the third part is vertical or within 5 of the vertical.

9. An assembly as claimed in any one of the preceding claims wherein the second part is calibrated to indicate the required position of the anchor means for a range of different orientations between the first and second parts.

10. An assembly as claimed in any one of the preceding claims wherein the three parts comprise longitudinal frame members joined together as three pivotally interconnected frameworks.

11. An assembly as claimed in any one of the preceding claims which, when not in use, can be folded substantially flat.

12. An assembly as claimed in any one of the preceding claims wherein the or a man-supporting surface is provided or supported at a second location positioned above the one it will occupy when the man-supporting surface is provided or supported by the first part of the assembly.

1 3. An assembly as claimed in Claim 12 wherein the man-supporting surface is supported at the second location by an upward extension of the third part and by a fourth part which shares the pivotal connection between the first and second parts.

14. An assembly as claimed in Claim 12 or Claim 1 3 wherein the man-supporting surface at the second location comprises or engages strut means interconnecting the third and fourth parts to provide a rigid structure.

1 5. An assembly as claimed in Claim 1 and substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.