WO2009127818A1

WO2009127818A1 - Safety unit

Info

Publication number: WO2009127818A1
Application number: PCT/GB2009/000961
Authority: WO
Inventors: John Gerard Gallagher; Lewis Alberto Grijo Dos Santos
Original assignee: Turner Access Limited
Priority date: 2008-04-18
Filing date: 2009-04-14
Publication date: 2009-10-22
Also published as: GB0906279D0; GB0807095D0; GB2459181B; GB2459181A

Abstract

A safety unit (5) for use with a scaffolding structure (40) or other structure, the unit comprising a support means (52) supporting a worker's platform (10) at an elevated position above the ground or a working deck of the structure, a fall prevention barrier (15, 20A, 20B) surrounding at least part of the worker's platform, access means (65) for climbing from the ground or working deck to the worker's platform, and securing means (35) for securing the unit to the structure for stability. The support means comprises one or more pairs of legs (52) which support the platform from the ground or working deck.

Description

SAFETY UNIT

Field of Invention

The present invention relates to a safety unit. In particular, though not exclusively the invention relates to a safety unit for use in or on structures such as scaffold or scaffolding.

Background of Invention

Scaffold installations typically have guardrails around platform levels in order to prevent users working on the scaffold from falling. Edge protection may also be provided at the top of elevated surfaces. However, whilst these semipermanent protection means, once installed, are useful in preventing falls by workers using the scaffold, alternative protection devices are often required for workers involved in constructing, assembling, repairing or altering the scaffold.

Traditionally, in order to comply with Health and Safety Regulations and statutory obligations thereof such as the UK Health and Safety at Work Act and Work at Height Regulations, protection is provided through the use of harnesses that tether to already constructed parts of the scaffold or other anchor points. However, harnesses only serve to arrest a fall, not prevent it. Even short falls have the potential for resulting in serious injury. In addition, the harness and the trailing tether limit motion and result in a risk of entanglement or entrapment. A pan European Directive on falls from height and UK Work at Height Regulations stipulate that prevention measures should be adopted before mitigation measures.

Systems that seek to prevent falls rather than mitigate their effects have been developed. Developments of this concept include advanced guardrails, such as the system of WO03025311 (Turner Access) or the PlusGard® system (US2006000673 PlusEight Safety). Advanced guardrails provide a fixed Guardrail that is installable from a secure position on a lower level, such that when the scaffolder proceeds to the higher level, there are Guardrails already in place to prevent falling.

The PlusGard® system, consists of uprights with a Guardrail extending between them. The uprights are provided with coupling devices for releasably coupling the uprights to the scaffold. The Guardrail is connected to the uprights via articulated connections. By uncoupling, moving and recoupling the uprights, the vertical position of each upright can be adjusted so as to raise or lower the Guardrail, for example, to position the Guardrail to protect a higher level that has not been constructed and provided with permanent Guardrails. The PlusGard® comes in component form and can be assembled and disassembled for transport and storage and appropriately sized components can be selected for each job.

However, despite the fact that factors such as litigation and new safety regulations have increased the importance of risk prevention, there is resistance to the use of advanced guardrails.

Although advanced guardrail products are not difficult to understand or use, they do require pre-planning for use and selection of appropriate quantities and parts. The amount and size of the parts needed varies from job to job depending on the configuration and bay lengths of the scaffolds involved.

In addition, the use of advanced scaffolding can add extra materials due to the components of the advanced guardrail itself and also additional scaffolding components required when using the advanced guardrail. This adds time and weight to each job and also results in the need to bring temporary assembly/dismantle aid items to and from each job.

It is an object of the present invention to provide a safety unit for use with a scaffolding structure or other structures which obviates or mitigates at least one problem in the prior art. Summary of Invention

According to a first aspect of the present invention there is provided a safety unit for use with a scaffolding structure or other structure, the unit comprising a support means supporting a worker's platform at an elevated position above the ground or a working deck of the structure, a fall prevention barrier surrounding at least part of the worker's platform, access means for climbing from the ground or working deck to the worker's platform, and securing means for securing the unit to the structure for stability.

The support means comprises one or more pairs of legs which support the platform from the ground or working deck.

The legs and/or fall prevention barrier are foldable into planes generally parallel to the platform when the unit is in a non-operative collapsed condition.

Preferably the legs and/or the fall prevention barrier are constructed from lengths of hollow tubular material which is joined by articulated joints to allow the unit to be folded into its non-operative collapsed condition.

This combination minimises the weight of the unit. The weight of the unit is preferably less than 24kg.

Locking means are provided to lock the folding legs and/or fall prevention barrier in an erected operative condition.

The access means may comprise rungs carried by the legs.

Preferably the fall prevention barrier includes at least one access gate.

The securing means may be designed to engage a horizontal rail of a scaffolding structure.

For example, the securing means may comprise a pair of hooks which grip the horizontal rail. The hooks may include friction means (such as rubber blocks) for contact with the horizontal rail.

In another form of the invention the legs extend upwardly above the platform to form part of the fall prevention barrier and access rungs extend between the legs.

The fall prevention barrier may also include a rear frame on which the platform is pivotally mounted and which includes vertical posts joined by one or more generally horizontal bars.

The fall prevention barrier also includes one or more further horizontal bars which connect the leg extensions and rear frame vertical posts.

Openable access means extend between the upward leg extensions to allow access to the platform for an operator using the access rungs. This openable access means preferably comprises a gate pivoted on one of the upward leg extensions.

In the above design the securing means is in the form of a pair of hooks to hook over a generally horizontal rail of a scaffolding and the rear frame vertical posts extend downwardly below the platform to form horns which hook behind a lower generally horizontal rail of the scaffolding to prevent toppling of the unit when in use.

A further hook may also be provided which is spring mounted on the unit and which hooks under the lower horizontal rail to ensure that the hooks and horns remain in contact with their respective rails.

The further horizontal bars which connect the leg extensions and the rear frame posts are pivoted in their central regions so that the unit can fold with the rear frame and upward leg extension lying generally parallel to each other. Preferably the platform is also pivotally connected with a bar which extends between the legs by a pair of arms, one end of each arm being pivoted to the platform and the other end to the bar which extends between the legs so that, as the unit is folded, the platform is pivoted into a plane generally parallel to the planes of the upward leg extensions and rear frame, the platform resting on said bar when the unit is opened up and in its operating condition.

In an alternative construction without legs the support means and securing means may be provided by separate sets of hooks which engage different generally horizontal rails of the scaffolding.

The platform may be dimensioned to provide a work space for a single operator.

In an alternative arrangement the platform is dimensioned to provide a working space for two or more operators in a side by side configuration.

It will be appreciated that the safety unit may be used on or with other structures, such as open frame metal mesh structures or structures formed from elongate metallic members, that are found in other environments, for example, masts, towers, pylons, derricks, rigs or cranes.

The elevation of the platform provides access to a not yet fully constructed upper level of a scaffold which may not yet have permanent or semi- permanent protection, such as an outer scaffold guardrail in place. The safety unit provides both access and anti-fall protection whilst working on the upper level and particularly whilst installing or removing the new permanent guardrail on the upper level.

By making the safety unit portable, the device may be moved from one area of work to another easily. The unit is sized so as not to fit the scaffold like advanced guardrails. This means that a single unit can be used for a wide range of different sized and shaped scaffolds. As indicated above, the fall prevention barrier preferably extends around all four sides of the platform and is provided with an access section, such as a gate, which is biased into a closed position. In this way, complete protection from falls on all sides can be achieved, yet still allow for access onto the platform. The biasing of the access section mitigates the effects of the user forgetting or incorrectly closing the access section, and prevents the access section opening during use.

The access section may be selectively lockable in an at least partially open configuration such that it forms a guardrail for users using the ladder.

In the non-operative configuration, the safety unit may fold substantially flat and/or into a more compact configuration than the operating configuration. In this way, the safety unit may be moved and stored easily. This makes the unit both stackable and easy to carry. Furthermore, this feature allows for rapid assembly/disassembly of the device as the safety unit needs only to be unfolded and locked in position to be ready for use. The device can be used with a range of scaffold sizes and types without the need for special selection or assembly of components. These features are important, as problems in transporting the safety unit from work area to work area or difficult or time consuming assembly will dissuade users from using the safety protection system and encourage unsafe practice.

According to a second aspect of the present invention there is provided a structure, such as a scaffold, having at least one safety unit according to the present invention secured thereto.

According to a third aspect of the invention there is provided a method of working on a scaffolding structure comprising securing a safety unit according to the first aspect of the invention to the structure to allow assembly or disassembly of an elevated stage of the structure whilst providing fall prevention protection for workers standing on the platform of the safety unit. Brief Description of Drawings

Various aspects of the invention will now be described, by way of example only, with reference to the accompanying drawings, of which:

Figure 1 the safety unit of the present invention in a folded configuration for handling, transport and storage;

Figure 2 the safety unit of Figure 1 with a first front/back mid-handrail unfolded;

Figure 3 the safety unit of Figure 1 with both front and back mid-handrails unfolded;

Figure 4 the safety unit of Figure 1 having full guardrails unfolded and the side guardrails (gates) open;

Figure 5 the safety unit of Figure 1 having all guardrails unfolded and the side guardrails (gates) closed;

Figure 6 the safety unit of Figure 1 having all guardrails unfolded and one of the legs partially unfolded;

Figure 7 the safety unit of Figure 1 having all guardrails unfolded and both legs fully unfolded;

Figure 8 the safety unit of Figure 1 in an operable configuration, having all guardrails unfolded, both legs fully unfolded, the leg base plates positioned and the access rungs unfolded;

Figure 9 the safety unit of Figure 1 in an operable configuration, having all guardrails, both legs, base plates and access rungs fully unfolded and the side guardrails (gates) open; Figure 10 the safety unit of Figure 1 in an operable position and mounted to a scaffold;

Figures 11a to 11f show stages in the erection of the safety unit on a scaffold;

Figure 12 shows a perspective view of an alternative safety unit in accordance with the present invention with its guard gate closed;

Figure 13 shows the unit of Figure 12 with its guard gate open;

Figure 14 shows a rear perspective view of the unit of Figure 12;

Figure 15 shows a perspective view of the unit of Figure 12 in its folded non-operative condition, and

Figure 16 shows diagrammatically a double width safety unit for two workmen.

Detailed Description of Drawings

Figures 1 to 11 show a safety unit 5 that is a collective protection platform (CPP) or collective protection unit (CPU). Such a safety unit is known as a GuardAid CPP or CPU. The unit is particularly advantageous in the assembling and disassembling of scaffolds, particularly in providing fall prevention (collective protection) in parts of the scaffold for which permanent fall protection is not yet assembled or has to be disassembled, repaired or altered. However, it would be appreciated by the skilled person that the device could be used to provide protection for users in other situations, for example, in working at height on other open mesh structures such as masts, pylons, derricks, cranes or towers, where fall protection is at least only partially present or needs to be assembled, disassembled or altered or needs to be supplemented for a safe work at height activity to be carried out. For example, this could be when working above permanently installed edge protection on a gantry.

The safety unit 5, as shown in Figures 1 to 11 , consists of a platform 10 having a plurality of tangentially projecting supports 15 for a series of guardrails 2OA, 2OB at varying heights above the platform 10. The guardrails 2OA, 2OB run around the perimeter of the platform 10 and together serve as fall prevention barriers. The rails 2OA, 2OB, and supports 15 are formed from hollow metal tubing, such as aluminium tubing, and are connected together and to the platform using lockable articulating joints 30. This allows the safety unit 5 to fold between a compact, substantially flat state, as shown in Figure 1 , wherein the platform 10, supports 15, and rails 2OA, 2OB align for transport and storage and unfolded, extended operational states, as shown in Figures 4 and 5, and 8 to 10, wherein the supports 15 are substantially perpendicular to the platform 10 and rails 2OA, 2OB. Additional diagonal spars 25, also formed from hollow aluminium tubing, may be used to brace the structure (see Figures 11a to 11 f).

As will be apparent to a person skilled in the art, suitable releasable locking means (not shown) are necessary to selectively lock the safety unit 5 in the unfolded operational state. The safety unit 5 is open at the top, to allow the user to work and carry out tasks outside the safety unit 5.

The safety unit 5 has mounting/securing members 35 for securing the device 5 to scaffolding 40, as shown in Figure 10. Examples of suitable securing members 35 include universal fixings, such as a brace hook connection claw with integral latches as found on the Turner Aluminium Octo Tower.

Figure 10 shows the lower level of a scaffolding structure 40 which is stood on the ground, it has horizontal rails 45 and 50 which correspond in height to the top and mid guard rails of higher levels of the scaffold. In the arrangement shown in Figure 10 two extendable legs 52 with foot pads 52a are provided that support the platform 10 from the ground (of from the decking of a higher level of the scaffold if the safety unit is used on a higher scaffold level). The unit is attached to the higher rail 45 by hook claws 35 which may include rubber pads which contact rail 45 to prevent slippage of the unit relative to rail 45. Extendable rungs or steps 65 are provided on legs 52 to give access to the elevated platform 10.

The fall prevention barriers are provided with access sections 60 in the form of gates 60 which are hinged for movement as indicated by arrows X and Y in Figure 9. These gate sections 60 are preferably biased to the closed condition shown in Figure 10 and are provided with latching devices (not shown) to hold them in their closed positions to complete the fall prevention barriers.

Figures 11a to 11f show the erection process for the safety unit shown in Figure 10.

In Figure 11a the operator 100 is stood inside the bottom level of the scaffolding and begins to unfold the safety unit (as also shown in Figures 1 to 5). In Figure 11b the fall prevention barrier is fully erected, as also shown in Figure 6, and the operator begins to unfold the support legs 52. In Figure 11c the unit is secured to rail 45 using hooks 35, and the legs 52 and rungs 65 are fully unfolded in Figure 11d (also shown in Figure 8). The operator can now climb onto platform 10 (see Figure 11e) and commence the erection or dismantling of the next higher level of scaffolding (see Figure 11f) in complete safety protected by the fall prevention barriers.

In an alternative construction legs 52 are not provided and, for example, the unit is provided with two sets of hooks 35 which secure the unit not only to rail 45 but also to either rail 46 of the next higher level of the scaffolding or to the mid rail 50.

In a still further alternative construction two pairs of legs 52 are provided to support the weight of the operator standing on the platform 10. In this arrangement hooks 35 are only used to secure the unit to the scaffold 40.

A still further form of the present invention is shown in Figures 12 to 15. In this construction platform 70 is supported from legs 71 which include steps or rungs 72. Legs 71 have an extended upper portion 73 which forms part of a fall prevention barrier which includes a rear frame 74 having vertical posts 75 and horizontal bars 76. The vertical posts 75 and leg extensions 73 are joined by further horizontal bars 77 which fold in their central regions using pivoting joints 78 which have sliding sleeves 79 which lock the bars in their operative non-folded configuration when the safety unit is in use. One suitable form of pivoting joint and locking sleeve arrangement is disclosed and claimed in UK patent application No.2442326.

Platform 70 is pivoted at 80 on vertical posts 75 which extend downwardly into horn portions 81 which are designed to hook behind rail 50 as shown in Figure 12 to stop the unit toppling over if the operator leans towards the rear frame 74. Hooks 82 hook over upper rail 45 and a fastening hook 83 mounted on a spring 84 is clipped under lower rail 50 to hold the safety unit down and prevent disengagement from the rails 45 and 50.

The platform 70 is provided with cut-outs 85 which, when the safety unit is in use, fit over a horizontal bar 86 which joins the legs 71. Platform 70 is also connected with bar 86 by arms 87 which are pivoted on bar 86 and also at pivot pins 88 on platform 70. Arms 87 ensure that when the safety unit is folded (as shown in Figure 15) the platform automatically folds to a raised position between extensions 73 and posts 75 and when the safety unit is unfolded into its working position (as shown in Figures 12 to 14) the platform

70 automatically folds down so that cut-outs 85 engage bar 86.

The fall prevention barrier is completed by a gate 90 which is pivoted on one of the extensions 73 by brackets 91 and has a catch or other fastening device 92 which secures the gate to the other extension 73.

As will be appreciated the safety unit of Figures 12 to 15 is of a robust construction in which the working platform is supported in an elevated position relative to the ground or scaffolding decking by the legs 71 and hooks 82 and in which the operator is fully protected by the fall prevention barrier as in the previously described constructions.

Figure 16 shows diagrammatically a double width safety unit for use by two workmen working side by side. The unit again folds flat like the unit shown in Figure 1 and has articulating joints 30, mounting members 35, four legs 52 and access rungs 65 extending between the pairs of legs. Additional bracing 66 is also provided between the legs.

A skilled person will appreciate that variations of the disclosed arrangements are possible without departing from the scope of the invention. For example, whilst the mounting members 35 are described as advantageously being a universal scaffold fixings, a skilled person would appreciate that other fixing means may be used, for example bolts, guy lines or tethers.

In a further optional embodiment, the safety unit is advantageously provided with anchoring points such as holes, hooks, loops or other suitable means, for anchoring the safety unit 5 when it is used on the top of elevated surfaces where convenient scaffold members may not be available for fixing.

Claims

1) A safety unit for use with a scaffolding structure or other structure, the unit comprising a support means supporting a worker's platform at an elevated position above the ground or a working deck of the structure, a fall prevention barrier surrounding at least part of the worker's platform, access means for climbing from the ground or working deck to the worker's platform, and securing means for securing the unit to the structure for stability.

2) A unit according to claim 1 in which the support means comprises one or more pairs of legs which support the platform from the ground or working deck.

3) A unit according to claim 1 or 2 in which the legs and/or fall prevention barrier are foldable into planes generally parallel to the platform when the unit is in a non-operative collapsed condition.

4) A unit according to claim 3 in which the legs and/or the fall prevention barrier are constructed from lengths of hollow tubular material which is joined by articulated joints to allow the unit to be folded into is non- operative collapsed condition.

5) A unit according to claim 4 in which locking means are provided to lock the folding legs and/or fall prevention barrier in an erected operative condition.

6) A unit according to any one of claims 2 to 5 in which the access means comprises rungs carried by the legs.

7) A unit according to any one of claims 1 to 6 in which the fall prevention barrier includes at least one access gate. 8) A unit according to any one of claims 1 to 7 in which the securing means is designed to engage a horizontal rail of a scaffolding structure.

9) A unit according to claim 8 in which the securing means comprises a pair of hooks which grip the horizontal rail.

10) A unit according to claim 9 in which the hooks include friction means for contact with the horizontal rail.

11) A unit according to claim 2 in which the legs extend upwardly above the platform to form part of the fall prevention barrier and access rungs extend between the legs.

12) A unit according to claim 11 in which the fall prevention barrier also includes a rear frame on which the platform is pivotally mounted and which includes vertical posts joined by one or more generally horizontal bars.

13) A unit according to claims 11 and 12 in which one or more further horizontal bars connect the leg extensions and rear frame vertical posts.

14) A unit according to any one of claims 11 to 13 in which openable access means extend between the upward leg extensions to allow access to the platform for an operator using the access rungs.

15) A unit according to claim 14 in which the openable access means comprises a gate pivoted on one of the upward leg extensions.

16) A unit according to any one of claims 11 to 15 provided with a securing means in the form of a pair of hooks to hook over a generally horizontal rail of a scaffolding and the rear frame vertical posts extend downwardly below the platform to form horns which hook behind a lower generally horizontal rail of the scaffolding to prevent toppling of the unit when in use.

17) A unit according to claim 16 in which a further hook is provided which is spring mounted on the unit and hooks under the lower horizontal rail to ensure that the hooks and horns remain in contact with their respective rails.

18) A unit according to claims 12 and 13 in which the further horizontal bars are pivoted in their central regions so that the unit can fold with the rear frame and upward leg extension lying generally parallel to each other.

19) A unit according to claim 18 in which the platform is also pivotally connected with a bar which extends between the legs by a pair of arms, one end of each arm being pivoted to the platform and the other end to the bar which extends between the legs so that, as the unit is folded, the platform is pivoted into a plane generally parallel to the planes of the upward leg extensions and rear frame, the platform resting on said bar when the unit is opened up and in its operating condition.

20) A unit according to claim 1 in which the support means and securing means are provided by separate sets of hooks which engage different generally horizontal rails of the scaffolding.

21) A unit according to any one of claims 1 to 20 in which the platform is dimensioned to provide a work space for a single operator.

22) A unit according to any one of claims 1 to 20 in which the platform is dimensioned to provide a working space for two or more operators in a side by side configuration. 23) A scaffolding structure having at least one safety unit according to any one of claims 1 to 22 secured thereto.

24) A method of working on a scaffolding structure comprising securing a safety unit according to any one of claims 1 to 22 to the structure to allow assembly or disassembly of an elevated stage of the structure whilst providing fall prevention protection for workers standing on the platform of the safety unit.