GB2460622A - A carriage for attachment to scaffolding - Google Patents

Abstract

A carriage 10 for removable attachment to a scaffold structure 1 to facilitate the laying and removal of system boards of the scaffold structure, the carriage comprising conveyance means 12 to permit the carriage to move in a relatively unhindered manner along a proportion of the structure and a support platform 14 arranged to receive a scaffold system board and permit the carriage to be conveyed with the system board in engagement therewith. The carriage may be configured to attach to a scaffold guard rail by first rollers 20a, b arranged to transmit a substantially vertical load to the scaffolding structure and second rollers 22a, b arranged to transmit a substantially horizontal load to the scaffold structure.

Description

I

A CARRIAGE AND A METHOD OF USING THE SAME

The present invention relates to a carriage and a method of using the same. More particularly, the present invention relates to a carriage for removable attachment to a scaffold structure to facilitate the erection and dismantling of parts of that structure. It also relates to a method of using the carriage to erect or dismantle the structure.

Scaffold systems are employed on construction sites to provide temporary access to structures during construction, or they are used to provide temporary access to existing structures for maintenance. They generally fall into two categories.

Tube and fitting scaffold systems are the longstanding way by which such temporary access platforms are erected. Tube and fitting scaffolding is flexible, but can be time consuming to construct.

In more recent years proprietary scaffold systems such as the applicant's own, as well as competing system from the likes of SGB CuplokRTM, Kwikstage'TM, LayherRlM, Pen and ASP enable platforms to be built from standardised modular components more rapidly.

The safety regulations and standards to which scaffold erectors must adhere are becoming increasingly strict. For example, in the UK, the Work at Height Regulations 2005 set out a framework for ensuring that scaffold erectors are able to operate safely during all stages of erection, alteration and dismantling of scaffold platforms. Specific provision is made for this in Schedule 3, Part 2. In particular the risk of them falling from structures should be minimised. Consequently, the erectors expect the manufacturers of such scaffold systems to be able to provide the appropriate equipment and methodologies to enable them to work safely when above the ground.

The present applicant has identified one area in which the safety and efficiency of proprietary scaffold systems can be improved, namely the laying and removing of system boards that are used to form the platform walkways. Hitherto, no system that is both safe and efficient in terms of the use of system boards has been devised.

The present invention seeks to overcome, or at least mitigate the problems of the prior art.

Accordingly, one aspect of the present invention provides a carnage for removable attachment to a scaffold structure to facilitate the laying and removal of system boards of the scaffold structure, the carriage comprising conveyance nieans to permit the carriage to move in a relatively unhindered manner along a proportion of the structure and a support arranged to receive a scaffold system board and permit the carriage to be conveyed with the system board in engagement therewith.

A second aspect of the present invention provides a method of laying or removing scaffold system boards of a scaffold structure using a carriage according to any preceding claim; the method comprising the steps of: a) placing one end of the system board on the support portion; and b) conveying the system board along a portion of the structure with a first end supported by the carriage.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: FIGURE 1 is an isometric view of a carriage according to an embodiment of the present invention; FIGURES 2A and 2B are side and end views respectively of an upright portion of the carriage of Figure 1; FIGURES 3A and 3B are plan and end views of a platform portion of the carriage of Figure 1; FIGURES 4 to 7 are isometric views illustrating various stages of the operation of the carriage of Figure 1; and FIGURE 8 is an isometric view of a carriage according to a second embodiment of the present invention.

With reference to Figure 1, a carriage 10 according to one embodiment of the present invention is shown attached to a single bay of a partially erected platform I of the applicant's proprietary scaffold system known by the registered trade mark HAKI. The scaffold platform is constructed from a plurality of standards 2 (only one visible) in Figure, ledgers 4 and transoms 6 (only one visible) in Figure 1. The platform additionally comprises a guard rail 8, including a pair of horizontal bars 9a and 9b arranged at a distance of 500mm apart vertically.

It is apparent from Figure 1 that the various components 2, 4, 6, 8 slot together using a standard interface. Other modular scaffold systems such as those mentioned above comprise a similar range of standard components that fit together using standard coupling interfaces.

Although these are different from the HAKI system, they also aim to provide a simple erection method.

The HAKI system and other scaffold systems use standard length system boards that extend between the transoms 6 and engage therewith to form the walkways. The weight of the system boards prevent a scaffold erector standing on an adjacent bay from placing the system boards between the two transoms 6. This makes it difficult to lay system boards safely. This problem usually does not occur for T&F scaffolds since the boards used are longer than bay lengths and can therefore be manipulated safely.

The carriage 10 of a first embodiment of the present invention comprises two major portions, an upright portion 12 for attachment to the platform 1 and a substantially horizontal support portion 14 pivotably attached thereto.

With reference to Figures 2A and 2B, the upright portion 12 is shown in more detail. The upright portion 12 comprises first and second vertical frame members l6a, 16b joined together by first, second and third horizontal frame members I 8a, I 8b and 1 8c, with the first and third horizontal frame members being located at the top and bottom of the vertical frame members respectively. The second horizontal member is located at the approximate mid-point of these two. In this embodiment the various members are manufactured from steel and welded together. In other embodiments other suitable materials (e.g. aluminium, composites such as GRP) and other connection methods such as fasteners or adhesives may be used.

First and second rollers 20a and 20b are rotatably mounted at the intersection of the first and second vertical frame members 16a, 16b with the first horizontal frame member 18a. The axes of rotation of the rollers 20a and 20b are substantially horizontal in use and extend substantially normal to the place of the upright portion U. The rollers 20a, 20b are recessed, as can be seen in Figure 2B in particular, to provide a good engagement with the circular profile of the upper guard rail bar 9a.

The upright portion 12 also comprises third and fourth rollers 22a and 22b that are mounted to the second horizontal frame member 18b adjacent to the first and second vertical frame members 16a and 16b respectively. The third and fourth rollers 22a and 22b are mounted for rotation about a vertical axis, i.e. an axis substantially parallel to that of the upright portion 12 as a whole. The third and fourth rollers 22a and 22b are substantially cylindrical in shape and are spaced vertically from the first and second rollers such that they may roll along the lower guard rail bar 9b whilst the first and second rollers are engaged with the upper guard rail bar 9a. Thus, vertical loadings are transmitted from the carriage 10 to the guard rail 8 by the first and second rollers, whereas horizontal loadings are transmitted by the third and fourth rollers.

Finally, the upright portion 12 comprises first and second bores 24a and 24b in the first and second vertical frame members 16a and 16b respectively that are substantially axially aligned and are located towards the lower end of the upright portion, in the vicinity of the third horizontal frame member 18c, and which are used to mount the support portion 14, as discussed in more detail below.

Turning to Figures 3A and 3B, the support portion 14 of the carriage 10 is shown in more detail. The support portion comprises a connecting beam 26 that extends between the first and second vertical frame members l6a and 16b and is provided with first and second tubular mounting brackets 28a and 28b dimensioned to receive appropriate bolts 30a and 30b that connect the support portion 14 to the upright portion 12 in a pivotable manner via bores 24a and 24b. A stop 31 is provided beneath the connecting beam 26 that engages the third horizontal frame member 18 in order that the support member, in use, is prevented from pivoting beyond the horizontal position shown in Figure 1.

The support portion 14 further comprises first and second system board engagement members 34a and 34b that extend perpendicular to the plane of the upright portion 12 when in use, and are provided at the extreme ends of the support portion 14. A connecting structure comprising a plurality of connecting beams 36a to 36e is arranged to connect the system board engagement members 34a and 34b to the connecting beam 26. Although a particular arrangement is illustrated in Figures 1 and 3a, it will be appreciated that numerous alternative arrangements could be provided (see, for example, the carriage of Figure 8).

With reference to Figure 1, it can be seen that the carriage 10 can be easily dropped into place on the guard rail 8, and by virtue of the rollers 20a, 20b, 22a, 22b can be easily moved along the length of the guard rail 8. However, when the end of a scaffold bay is reached, the rollers will contact one of the standards 2 and therefore will not be able to roll any further. The support portion 14 of the carriage 10 is located within the space that is ultimately to be covered with scaffold system boards, but can be pivoted upwardly into a position approaching alignment with the upright portion 12 when being transported to and from the location illustrated in Figure 1.

A piece of rope (not shown) may be attached to the carriage in order that when pushed to an end of a scaffold bay remote from a scaffold erector, the erector can pull the rope to bring it back to a position next to the erector. The rope is preferably provided with a clip at its free end to attach it to the scaffold structure so it does not drop out of reach of the erector and can also be used as an arrestor in the unlikely event that the carriage 10 is dislodged from the guard rail 8 or accidentally dropped.

With reference to Figures 4 to 7, the method of operation of the carriage 10 is illustrated.

In Figure 4, the carriage is located at the right hand side of a bay of a scaffold platform adjacent a second bay (not shown) that has already been fully erected, boarded and is safely accessible by a scaffold erector. To further enhance safety the erector may place a temporary guard rail (not shown) between the standards at the end of the boarded bay In Figure 5, the erector has placed a scaffold system board 38 having a pair of hook members onto the carriage 10 such that the hook members engage with the system board engagement member 34a thereof. Clearly, if assembly were to take place in the opposite direction (i.e. from an already erected platform to the left of the one shown in Figure 5) the hooks 40 would be engaged with the system board engagement member 34b on the other side of the support portion 14.

In Figure 6, the erector has pushed the system board and carnage from right to left in a direction X, to the point at which the hooks 40 are adjacent to transom 6. It will be appreciated that a single erector would be unable to stand on a platform to the right of that illustrated in Figure 6 and have sufficient strength to extend the system board 38 safely over the partially erected platform 1 to the position shown in Figure 6 without the carriage 10.

In Figure 7, by a combination of lowering the end of the system board remote from the carriage 10 and sliding the system board from right to left, the erector has disengaged the hooks 40 from the engagement member 34a and has engaged the transom 6. However, the support portion 14 of the carriage continues to support the system board 38 whilst this manoeuvre is carried out. Once the hooks 40 have engaged the transom, it is possible for the erector to slide the system board 38 in the direction Y so that it is located adjacent the ledger 4 that is remote from the guard rail 8. The erector then pulls the carriage 10 back along the guard rail using the rope to return it to the position shown in Figure 4, and the process is repeated for subsequent system boards 38.

To completely cover the space defined by ledgers 4 and transoms 6, five system boards are required using the applicant's system for the platform shown. For other platforms and for other systems, the number of system boards required varies depending on the depth of the platform (but is usually 3, 4,or 5). However, not all these can be installed using the carriage since at least one is obstructed by the carriage itself. Thus, the final one or two system boards are installed after the carriage 10 has been lifted clear of the guard rail 8. This is achieved by sliding these system boards along the already installed system boards 38 until they extend right the way across to the far transom 6. Once in this position, they can be slid in the opposite direction to arrow Y off the already installed system boards and into engagement with both of the transoms 6 to provide a complete covering of the space defined by ledgers 4 and transoms 6.

The above described method can then be repeated for each successive bay along the length of a scaffold structure.

The carriage 10 is also equally applicable when removing system boards when they are to be placed on a higher platform level. This operation is usually carried out repeatedly as the construction of a building or other structure progresses, and access at higher levels is needed.

In addition, the carriage 10 is intended to be used during the dismantling of the scaffold structure.

In these instances, the first system boards 38 nearest to the guard rail 8 may be removed by being rolled onto adjoining system boards and then slid back using the adjoining system boards as support. When using the removed system boards at a higher level, the can be placed in the bay directly above the erectors.

However, the final system board does not have any adjoining system boards for support during its removal. Thus, it has previously been necessary for single system boards to be left behind as the construction of a building progresses, which is inefficient in terms of utilisation of such system boards, or scaffold erectors have undertaken risky operations to remove the final system board.

Using the carriage 10, however, this final system board can be slid along the transom 6 and then manipulated so that hooks 40 engage with the engagement member 24a, and the trolley pulled back towards the erector using system board 38.

It will therefore be appreciated that the carriage according to the present invention and the associated method of using the carriage enables the safe installation and removal of scaffold system boards in modular scaffold systems. It also permits the minimum number of system boards to be used during the construction of a building when the requirement is for platforms to be provided on progressively higher levels.

Referring to Figures 8 and 9, an alternative embodiment of the carriage according to the present invention is shown. Like parts of the carriage of Figure 8 are labelled with like numerals to the carriage of the first embodiment, with the addition of the prefix "1". Only the differences with respect to the carriage of the first embodiment are discussed in more detail.

The carriage 110 of the second embodiment comprises larger first and second rollers 120a and 120b compared with that of the first embodiment, in order to enable it to roll more smoothly along the guard rail 8. The rollers 120a and 120b are connected to the vertical frame members 11 6a and 11 6b at a slightly lower location. In addition, the pivot arrangement between the upright portion 112 and the support portion 114 is now located out of alignment with the upright members I 16a and I 16b, thereby enabling the support portion 114 to be folded into a position parallel with the plane of the upright portion as can be seen in Figure 9.

This enables the carriage 110 to be more compact for storage and transportation. A single rod 130 provides the pivotable connection between the upright portion 112 and support portion 114. Box section profile members are used to construct the frame rather than angled profiles. First and second resilient (e.g. synthetic rubber) "buffers" are provided on the third frame member 126 to cushion the impact of stop members 131a and 131b when the support portion 114 is lowered.

The support portion comprises a simplified arrangement of connecting members 136a to 136d, thus reducing the amount of materials, welding and assembly time required.

A releasable catch arrangement 144 may be provided between the upright portion and the support portion to hold them in a parallel relationship during transportation, but to enable rapid deployment in use. The arrangement 144 comprises a pin 146 biased into a deployed position by a spring 148 (illustrated schematically). The pin engages with a hole 150 on connecting member 136c. The pin 146 is mounted to a vertical connecting bar 152 that connects the second horizontal frame member 11 8b with a fourth horizontal frame member 11 8d. The fourth horizontal frame member has a round profile to make it more comfortable to use as a handle.

First and second lugs 154a and 154b extend from the vertical frame members in the same direction as the axis of the first and second rollers 120a and 120b. The lugs are located below the third and fourth rollers 122a and 122b to require a degree of pivoting motion in addition to vertical motion to engage the carriage 110 with the guard rail 108. This enhances the securing of the connection to the guard rail.

Various other changes may be made within the scope of the present invention. For example, the carriage may be adapted to be releasably secured to the ledgers only, rather than the guard rail, the arrangement of beams and connecting members may be adjusted as required, buffers may be provided on the carriage to mitigate the use of excessive force when rolling it from one side of a scaffold bay to another. The number of rollers may be increased or reduced as needed. The dimensions of the carriage may be adjusted for different components used in alternative modular scaffold systems, the system board engagement members may be altered in order to engage with different system board mounting arrangements used in different scaffold systems. For example, the system boards used in the KwikstageRTM and CuplokRTM systems do not have hooks, but rather have plain ends, thus, a raised lip may be provided on the system board engagement members in order that the system board can still be used to push the carriage along.

Claims (14)

1. Claims 1. A carriage for removable attachment to a scaffold structure to facilitate the laying and removal of system boards of the scaffold structure, the carriage comprising conveyance means to permit the carriage to move in a relatively unhindered manner along a proportion of the structure and a support arranged to receive a scaffold board and permit the carriage to be conveyed with the system board in engagement therewith.
2. 2. A carriage according to claim 1 wherein the carriage is configured to attach to a guard rail of the scaffold structure.
3. 3. A carriage according to claim 1 or claim 2 wherein the carriage attaches to the scaffold by a roller.
4. 4. A carriage according to claim 3 wherein the carriage attaches to the scaffold by a first roller arranged to transmit a substantially vertical load to the scaffold structure.
5. 5. A carriage according to claim 3 or claim 4 wherein the carriage attaches to the scaffold by a second roller configured to transmit a substantially horizontal load to the scaffold structure.
6. 6. A carriage according to any preceding claim wherein the carriage comprises an upright portion.
7. 7. A carriage according to any preceding claim wherein the support portion is substantially horizontal.
8. 8. A carriage according to any preceding claim wherein the support portion is pivotably mounted with respect to the remainder of the carriage.
9. 9. A carriage according to any preceding claim wherein the support portion comprises an engagement member configured to engage an end of a scaffold system board.
10. 10. A method of laying or removing scaffold system boards of a scaffold structure using a carriage according to any preceding claim; the method comprising the steps of: a) placing one end of the system board on the support portion; and b) conveying the system board along a portion of the structure with a first end supported by the carriage.
11. 11. A method according to claim 10 wherein the second end of the system board is supported by a person, the first end of the system board is conveyed from the person and into engagement with a portion of the scaffold structure remote from the person.
12. 12. A method according to claim 10 wherein the second end of the system board is supported by a person and the first end of the system board is conveyed from a portion of the scaffold structure remote from the person towards the person.
13. 13. A method according to any one of claims 10 to 12 further comprising a step prior to step 11 of engaging the carriage with the scaffold structure.
14. 14. A method according to claim 13 wherein the further step comprises engaging the carriage with a guard rail portion of the structure.