WO2013034915A1

WO2013034915A1 - Scaffolding dropper/hanger platform

Info

Publication number: WO2013034915A1
Application number: PCT/GB2012/052196
Authority: WO
Inventors: Richard D. G. LAWRIE; William Mohamed
Original assignee: Lawrie Richard D G; William Mohamed
Priority date: 2011-09-06
Filing date: 2012-09-06
Publication date: 2013-03-14
Also published as: GB201405707D0; GB2509277A; GB201115408D0; GB2495072A; GB201212776D0; GB2494503A

Abstract

A method of erecting or dismantling scaffolding. The method includes the step of engaging a platform with a longitudinal member, the platform disposed at a generally horizontal direction to the longitudinal member. The platform extends radially away from the longitudinal member by at least 5cm, and around at least three quarters of the circumference of the longitudinal member. The method also includes the step of hanging the longitudinal member from a support member in a generally vertical direction.

Description

Scaffolding Dropper/Hanger Platform Background The present invention relates to the field of scaffolding and relates particularly to the field of erecting scaffolding 'over the side', or from the top down with no support from below in both onshore & offshore industries.

When scaffolders currently erect scaffolding over the side, the standard practice is to attach a 1 foot (30cm) length of scaffolding tube perpendicular to a longer tube [2]. This configuration is known as a 'dropper' or 'hanger' [1], because it 'drops' or 'hangs' vertically downwards to provide somewhere for the scaffolder to place his feet so he can continue working below. Whilst this is accepted practise in the industry, the inventor of the present invention has noted a problem with this 'tee' piece [2], in that there is only one balance point under each foot, making the worker unstable. The scaffolder must maintain his balance whilst receiving scaffolding tubes up to 16 feet (4.87m) weighing approximately 20kg. The usual way is to stand on only one leg, with the other wrapped around the vertical part of the dropper, and with one hand firmly gripping the dropper, leaving only one hand free.

Another problem with the tee piece recognised by the present inventor is that as a single tube to stand on, the scaffolder has only two options of where to face, each 180 degrees from the other.

This restricted positioning of the feet coupled with poor balance means that the worker has a twisted body with all the weight in just one hand being directed on one side of the body. This increases the risk of immediate and long term musculoskeletal injuries.

In addition, the present inventor has also recognised that due to the restricted work positioning, the safety line that connects to a rear attachment point is sometimes in practice, unavoidably wrapped over the workers shoulder. This is uncomfortable to work with and can create complications in the event of a fall. Statement of Invention

According to a first aspect of the invention, there is provided a method of erecting or dismantling scaffolding, the method comprising:

engaging a platform with a longitudinal member, the platform disposed at a generally horizontal direction to the longitudinal member,

such that the platform extends radially away from the longitudinal member by at least 5cm, and around at least three quarters of the circumference of the longitudinal member; and hanging the longitudinal member from a support member in a generally vertical direction.

According to a second aspect of the invention, there is provided an apparatus used to support a person erecting or dismantling scaffolding, comprising a longitudinal member, a platform generally disposed at right angles thereto, extending radially away from the longitudinal member by at least 5cm, and around the longitudinal member by at least a quarter of the circumference of the longitudinal member.

A "generally vertical direction" is preferably vertical but can be offset by up to 10 degrees, normally up to 5 degrees away from the absolute vertical position.

A "generally horizontal direction" is preferably absolutely horizontal but can be offset by up to 10 degrees, normally up to 5 degrees away from the absolute horizontal position.

The step of hanging the longitudinal member from the support member may be after the step of engaging the platform with the longitudinal member.

In preferred embodiments, the longitudinal member is positioned vertically and the platform horizontal, and at right angles to the longitudinal member; all give or take 2- 3 degrees. Moreover, preferred embodiments of the platform extend more than half, normally more than three quarters and ideally all the way around the circumference of the longitudinal member. The support member may be an offshore oil rig or any other structure, including existing scaffolding above, from which the longitudinal member may be deployed.

Other features of certain embodiments of the invention are set out in the dependent claims.

To overcome the highlighted problems which all stem from the restricted positioning & balancing of the feet, this invention proposes a scaffolding platform to replace the tee piece that can be attached to the dropper [3].

This will enable the worker to place his feet anywhere 360 degrees around the dropper, preferably with heel and toe contact providing good balance.

As the worker is now well balanced he will not require his leg to be wrapped around the dropper, and leaning his upper body into the dropper, his two hands would be free to receive tubes and fittings.

The risk of physical injury is reduced, and the choice of feet position eliminates working with the safety line wrapped over a shoulder.

Thus embodiments of the invention provide a platform that can be attached to a scaffolding tube, with the resulting configuration acting as a 'dropper' - also known as a 'hanger' - to support a scaffolder working 'over the side', for example when erecting scaffolding from the top down with no support from below.

Normally the platform has a hole in the middle slightly larger than the outside diameter of a standard scaffolding tube, or any tube that is being used to form the vertical section of a 'dropper'. The invention may use a standard scaffolding fitting [18], that may or may not penetrate the platform, that is welded or otherwise attached to the platform, whilst allowing the fitting to be fastened securely around the scaffold tube.

Certain embodiments use a custom designed fitting that fastens around the scaffold tube and have adequate contact area with the underside of the platform to allow sufficient strength for welding or bolting the fitting to the platform; that may or may not penetrate through the platform.

The platform may sit on top of a standard scaffold fitting that partially or fully penetrates a corresponding recess in the underside of the platform.

The platform may have a collar that a standard scaffolding clip can engage and secure to a scaffolding tube. The clamping means may be a screw extending through the collar [1 1] engaging the longitudinal member.

The platform may have an adequate depth to provide stability against the vertical scaffold tube.

The platform may be shaped such as square, oval, circular, or any shape that will provide provision for support to worker on scaffold.

There is herein described an apparatus and method of erecting or dismantling scaffolding using a longitudinal member (normally a scaffolding tube) from a support member (such as an offshore installation) in a generally vertical direction; engaging a platform with the longitudinal member at a generally horizontal direction such that the platform extends radially away from the longitudinal member by at least 5cm, and around at least a quarter., normally three quarters of the circumference of the longitudinal member. The apparatus and method is particularly suited when erecting scaffold from the top down. This enables the scaffolder to have a much improved working position with good balance when compared to the traditional 'tee' piece dropper. It also eliminates the unplanned but un-avoidable, occasional situations where the safety line is wrapped over a shoulder or under-arm. This is uncomfortable to work with and can create complications in the event of a fall.

Detailed Description

Embodiments of the invention and various preferred features and advantages of it are further described below, by way of example only, with reference to illustrative embodiments shown in the drawings, in which: Fig. 1 shows a traditional 'dropper' with a 'tee' piece on the left, with the present dropper platform invention on the right; Fig. 2 shows a plan view of a possible dropper platform; Fig. 3 is an end elevation showing an example of how the dropper platform could be attached to the vertical pole using a standard 'double' scaffolding clip and Fig. 4 shows an alternative embodiment of a platform with a deeper cross-section to increase stability and a recess underneath to allow partial penetration of a standard scaffold clip; Fig. 5 shows the preferred design with one option of how it is secured to a scaffold tube; Fig. 6 shows a standard commercially available pressed double scaffolding clip, this particular one manufactured by Presco Components.

Embodiments of the invention are for use when erecting scaffolding from the top down, or dismantling from the bottom up, for example, when working 'over the side' on an offshore platform where there is no support from below.

The platform [3] is circular with a hole in the middle slightly larger than the outside diameter of a standard scaffolding tube [4] (or any alternative support used for the vertical section of the dropper). Since the platform is circular, it extends around the entire circumference of the scaffolding tube 4.

The platform is made of a material strong enough & of adequate thickness to guarantee support of a scaffolder and equipment, preferably galvanized or coated carbon steel and preferably with a thickness of 6mm or less for methods 1 & 2 detailed below, and potentially a polymer for method 3.

The platform is large enough to provide contact for heels and toes, preferably with a diameter of 12 inches (30cm). Thus with the ~5cm central aperture, the platform in this exemplary embodiment extends radially out from the tube by 12.5cm (from the edge of the central aperture to the edge outer circumference of the platform [8], and extends around the entire circumference of the scaffolding tube.

The platform is securely attached to a scaffolding tube. The four methods of attachment described below also determine the specification of the platform itself. These four methods are not exhaustive, but aim to illustrate the concept of this innovative platform in various guises. Method 1

A standard commercially available, weight bearing 'double' scaffolding clip [6 &1 1] could be used with one section of the clip welded closed [7] and the top protruding through the scaffolding platform [8]. The platform has the corresponding section removed adjacent to the centre hole to accommodate the penetrating clip [5].

The protruding section can then be welded to the upper side of the platform [9]. This configuration is designed so the platform rests on the clip with the weld providing stability. The other section of the clip is free to open and close as in normal clip operation. The scaffolding tube is slid through the platform with the clip on the underside tightened in the usual fashion to provide the dropper configuration ready to be lowered and secured in place as in traditional use.

Method 2

A scaffolding clip could be specially designed with the usual method employed for attaching to the scaffold tube, but with a flat top side of adequate surface area to allow welding (or bolting) to the underside of (or through) the platform. This would mean that the platform only requires the centre hole for the scaffolding tube to slide through (plus drilled holes if bolting is used), and no section of the clip protrudes through the platform. Method 3

The platform could be made with greater depth to methods 1 & 2, preferably of a lighter material with adequate strength, designed to slide on top of a standard scaffolding clip [10]. This platform would be manufactured to allow partial penetration of the clip into the underside of the platform. This would inhibit rotational movement, and the depth allied with the snug fit around the scaffolding tube would limit lateral movement. Gravity with the platform resting on the clip would inhibit vertical movement. A simple mechanism could potentially be engineered to lock the penetrating part of a double scaffolding clip in place, or a simple, lockable leverage clip could bring a full radius narrow gap under tension, thus entirely securing the platform.

Method 4

The preferred design is circular with a central hole of a diameter slightly greater than that of a standard scaffold tube (currently 48.3mm). This is approximately 51 mm to allow annular space for ease of sliding over a scaffold tube without catching. The optimal diameter of the platform is around 300mm. This is sufficient to provide heel and toe contact for the worker, but not too large to make the unit overly heavy and cumbersome to use.

A tube with an inside diameter matching the central hole cut in the platform could be welded [16] to the underside of the platform, acting as a 'collar' [1 1 ] providing lateral stability. Alternatively, the central hole in the platform could be cut to match the outside diameter of the 'collar' tubing, so the tube is set through and flush with the top side of the platform, easing the setup for the welding / manufacturing process. An additional weld around the tube to platform interface on the top side could also be added.

The 'collar' tube should have an adequate wall thickness to guarantee integrity, preferably greater than 3mm. This 'collar' also provides the means of secure attachment, with one option being a standard 'double' scaffolding clip. The 'double' clip would be fastened around the scaffold tube with the upper 'contact ball' [12], or surface, clamping the 'collar' securely against one side of the scaffold tube [13], with the end of the 'collar' resting on the 'double' clip [14]. This will inhibit rotational, vertical and lateral movement.

The length of 'collar' tubing necessary on each unit must be at least equal to or greater than the distance the 'double' scaffold clip protrudes above the section that fastens around the scaffold tube [17]. This distance would ideally be kept to a minimum to save weight, with a length of approximately 40mm satisfactory. This height also makes the task of tightening the scaffold clip easier, although it is possible with the absolute minimum length of 'collar'.

4mm carbon steel plate can be used for the platform with extra holes punched into the plate in a way that creates a slightly raised 'lip' on the upper surface of the platform [15], thereby providing grip. Additional holes created with no raised lip can provide for water egress.

The number and size of holes punched for grip and water egress will depend on how much they weaken the structure, so a 6mm plate is able to have a greater number of holes than a 4mm plate for example. Finite stress analysis may indicate the number and size of holes for different materials and thicknesses, and destructive testing is used to ensure integrity. The carbon steel unit could be hot dip galvanized, or electrostatically coated with zinc to protect it from corrosion. The unit could also be fabricated from stainless steel, or die cast with aluminium. The die cast aluminium version could have additional 'stiffeners' from the collar to the underside of the platform adding strength while allowing the minimum material thicknesses saving on weight.

Thicknesses of materials different from those listed above could be used, providing satisfactory results were obtained during the destructive testing process to guarantee the integrity of the platform under any foreseeable working conditions. In an alternative embodiment, screws could be used penetrating the collar [1 1 ] to secure the platform to the longitudinal member.

The longitudinal member may be a variety of different scaffolding tubes including the new composite material type.

Claims

Claims:

1 . A method of erecting or dismantling scaffolding, the method comprising: engaging a platform with a longitudinal member, the platform disposed at a generally horizontal direction to the longitudinal member,

such that the platform extends radially away from the longitudinal member by at least 5cm, and around at least three quarters of the circumference of the longitudinal member; and

hanging the longitudinal member from a support member in a generally vertical direction.

2. A method as claimed in claim 1 , wherein the step of hanging the longitudinal member from the support member is after the step of engaging the platform with the longitudinal member.

3. A method as claimed in claim 1 or claim 2, wherein the platform extends radially away from the longitudinal member by at least 10cm.

4. A method as claimed in any preceding claim, wherein the platform has a surface area of at least 5 x 5 cm, optionally at least 8 x 8 cm.

5. A method as claimed in any preceding claim, wherein the platform includes at least one aperture through which the longitudinal member extends, and the platform is engaged to the longitudinal member whilst it is extending through said aperture.

6. A method as claimed in any preceding claim, wherein scaffolding is erected without any support from beneath the scaffolding

7. A method as claimed in any preceding claim wherein the platform comprises a collar extending from a planar face thereof.

8. A method as claimed in claim 7 wherein the collar is provided around the circumference of an aperture in the platform.

9. A method as claimed in claims 7 or 8 wherein a clamping means is used to clamp the scaffolding tube to engage it with the platform.

10. A method as claimed in any preceding claim, wherein the platform is engaged with the longitudinal member using a clip.

1 1. A method as claimed in claim 10, wherein the clip has a first portion which can engage with the longitudinal member and a second portion which extends through a socket provided in the platform.

12. A method as claimed in claim 10 or claim 1 1 , wherein the first portion of the clip has two arms pivotally disposed to each other, and a closing member.

13. A method as claimed in claim 12, wherein the closing member comprises a nut and bot.

14. A method as claimed in any one of claims 1 1 to 13, wherein the socket is one of a recess and an aperture.

15. A method as claimed in any preceding claim, wherein the longitudinal member is a scaffolding tube.