GB2339231A

GB2339231A - Apparatus for providing a scaffold safety screen and method therefor

Info

Publication number: GB2339231A
Application number: GB9814744A
Authority: GB
Inventors: Matthew Radley
Original assignee: RATNAVEL NANDIRAN
Current assignee: RATNAVEL NANDIRAN
Priority date: 1998-07-07
Filing date: 1998-07-07
Publication date: 2000-01-19
Anticipated expiration: 2018-07-07
Also published as: GB9814744D0; GB2339231B

Description

2339231 APPARATUS FOR PROVIDING A SCAFFOLD SAFETY SCREEN AND METHOD

THEREFOR This invention relates to an apparatus for providing a 5 scaffold safety screen and a method therefor.

During construction, demolition or maintenance of high structures such as multi-storey buildings, for example, it is often necessary to provide an adjacent temporary structure such as a scaffold for personnel and equipment access to various parts of the structure concerned. Health and safety considerations usually require erected scaffolds to have a safety screen- to prevent articles or debris falling from the scaffold into surrounding areas. Known safety screens comprise screens of sheet material secured directly to the scaffold at various points.

It is to be understood that the term "sheet material" used herein includes sheet material, net sheet material and any other sheet like material suitable for use in a scaffold safety screen. In addition, the term "scaffold" used herein includes any temporary structure which can be readily assembled on the face of a structure for access purposes.

A problem with known scaffold safety screens is that they provide little or no protection from falling articles or debris during erection of the scaffold. This problem arises because the safety screen for a particular level of scaffold is secured to the scaffold only after that level has been erected. Accordingly, the safety screen provides no protection from articles or debris falling from the level of scaffold that is in the process of being erected. This is a major problem since it is not uncommon for heavy scaffold components to be dropped by personnel during erection of scaffold. This is also a problem when the scaffold is being dismantled since the safety screen for the level of.scaffold in the process of being dismantled must be removed before any dismantling of the scaffold occurs.

Another problem associated with known safety screens is that they are cumbersome to handle on the scaffold, since the safety screen material has to be handled and transported about the scaffold manually and correctly positioned before being secured to the scaffold. This is labour intensive, time consuming and can be dangerous since there is usually minimal space on the erected scaffold for such activity. In addition, the safety screen provides little if any support if fallen into by a scaffold worker, for example as it is being secured to the scaffold.

A further problem with known safety screens is that they are generally erected in a piecemeal fashion such that gaps are likely to be left between adjacent sheets of safety screen material.

An object of the present invention concerns an apparatus for providing a scaffold safety screen which provides protection from falling articles or debris during erection and dismantling of the scaffold and which is relatively easy to position over the face of a structure.

Another object of the present 'invention concerns a method of providing a scaffold safety screen which provides protection from falling articles or debris during erection of the scaffold and which provides a relatively easy method for positioning a"scaffold safety screen over the face of a structure.

According to an aspect of the present invention there is provided an apparatus for providing a scaffold safety screen; said apparatus comprising:- a scaffold safety screen sheet material; and deployment means for deploying said sheet material from an elevated position towards a base of a structure to be - 3 scaffolded so as to provide a scaffold safety screen over an area of said structure.

Accordingly, the above apparatus enables scaffold safety screen sheet material to be deployed from an elevated position over an area of a face of a structure prior to the erection of scaffold. In this way, the safety screen can prevent articles, scaffold components or debris falling from the scaffold as it is being erected into an area on the other side of the sheet material. Thus, the safety screen can protect personnel in designated safe areas on the other side of the sheet material. This allows scaffold to be erected in a safe manner around structures which are located in areas accessible by the public. In addition, the safety screen can be deployed in a single operation. This saves time and reduces the labour required.

Preferably, said deployment means comprises spacer means for deploying said sheet material from a position spaced apart from said area of said structure. Since the spacer means allows the sheet material to be deployed from a position spaced apart from the face of the structure, scaffold can be erected in the space created between the sheet material and the face.

Conveniently, said spacer means comprises cantilever means. In this way the spacer means can be cantilevered from the structure to be scaffolded.

In preferred embodiments, said cantilever means comprises a cantilever arm having a guide means at a remote end thereof for guiding said sheet material over said arm. This reduces friction as the sheet material is deployed from the roll and over the face of the structure.

Preferably, said sheet material is provided as a roll and said deployment means comprises a spindle for deploying said sheet material from said roll. This optimises the above mentioned advantages and allows the sheet material to be readily deployed.

Conveniently, said spindle comprises drive means for deploying said sheet material. Thus, the safety screen 5 material can be deployed in a controlled manner In preferred embodiments, said sheet material comprises a net like sheet material. This optimises the strength to weight ratio of the sheet material and prevents high aerodynamic forces being developed on the sheet material in use by wind. Net like sheet material is also relatively inexpensive.

In other embodiments, said sheet material comprises a substantially continuous sheet.

Conveniently, said deployment means is provided with connection means for connection to said structure. In this way, the weight of the deployed sheet material can be supported by the deployment means.

In preferred embodiments, said apparatus further comprises sheet material support means for supporting said sheet material relative to said structure. Hence, the deployment means can be removed once the sheet material has been deployed and secured to the supporting means.

Preferably, said sheet material support means comprises part of an erected scaffold. Accordingly, the sheet material is secured directly to the scaffold being erected.

Conveniently, said apparatus further comprises sheet material positioning means for positioning said sheet material relative to structure.

In preferred embodiments, said sheet material positioning means is provided with positioning guide means at remote ends thereof. This reduces friction between the sheet material and the positioning means during movement of the sheet material over the remote ends of the positioning means.

According to another aspect of the present invention there is provided a method of providing a scaffold safety screen; said method comprising the steps of:- (a) positioning a scaffold safety screen sheet material at an elevated position on a structure to be scaffolded; and (b) deploying said sheet material from said elevated position towards a base of said structure to provide a scaffold safety screen over an area of said structure. This optimises the above mentioned advantages.

Preferably, said step (a) comprises the further step of positioning a free end of said sheet material at a position spaced apart from said area of said structure.

Conveniently, said further step comprises positioning said free end at a cantilevered position spaced apart from said structure.

In preferred embodiments, said step of positioning said free end of said sheet material at a cantilevered position comprises the step of positioning said free end over a guide means provided at the remote end of a cantilevered arm.

Preferably, said sheet material is provided as a roll and said deploying step comprises the step of rotating said roll to deploy said sheet material from said roll.

Conveniently, said method further comprises a step (c) of securing said sheet material to a sheet material support means provided between said structure and said sheet material.

In preferred embodiments, said sheet material is secured to said sheet material support means during erection of scaffold between said sheet material and said structure.

Accordingly, it is possible to secure the sheet material as the scaffold is being erected. This allows scaffold components and other articles to be readily recovered if dropped from the scaffold during erection of the scaffold.

Moreover, damage to dropped scaffold components is minimised reducing replacement costs. In addition, this avoids the above mentioned known problem of securing sheet material to the scaffold after it has been erected.

Preferably, said sheet material is secured to said sheet material support means in steps such that said sheet material is secured to said sheet material support structure up to a level of scaffold in the process of being erected.

Accordingly, the safety screen can arrest the fall of a person falling from the scaffold during erection of the scaffold. Conveniently, said step of securing said sheet material to a sheet material support means comprises securing said sheet material to said scaffold. is The invention will now be described by way of example only with reference to the accompanying drawings, in which:Figure 1 is a cross-section view of part of a scaffolded structure having a scaffold safety screen provided by an apparatus of the present invention; 20 Figure 2 is a part cross-section view of a scaffold safety screen deployment means. Figures 3a and 3b are respective plan and elevation views of the structure of Figure 1 in the direction of A and B respectively; 25 Figure 4 shows a scaffold safety screen support means; Figures 5a and 5b show a coonection means for securing the scaffold safety screen to the support means of Figure 4; Figure 6 is a plan view in the direction of A of a corner of the structure of Figure 1; 30 Figures 7a and 7b show a scaffold loading platform as part of a scaffold in views similar to Figures 1 and 2; Figure 8 is a perspective view of a suspended scaffold platform; Figures 9a and 9b show scaffold support means.

With reference to Figure 1, a scaffold 1 is shown erected around the outside face 2 of a structure which in the present case is a multi-story building 3. The building 3 has a ground floor 4 which is shown to the bottom of the drawing in Figure 1, a seventh floor 5, a fourteenth floor 6 and a flat roof 7. The scaffold 1 extends between the ground floor 4 and the roof 7. At seventh and fourteenth floor levels 5 and 6 the scaffold is provided with an angled support protrusion 8. The protrusions 8 each support an angled platform, termed a "protection fanff in the art, for catching falling articles or debris etc. Safety screen positioning means 16 are provided between the "protection fans". The safety screen positioning means 16 extend beyond the scaffold 1 in a direction away from the building face 2. It is to be understood that a "protection fan" is usually provided on every seventh floor of a multi-storey building. Accordingly, a "Protection fan" may not be required on buildings having less than seven floors.

An apparatus 9 is provided for deploying a scaffold safety screen along the chain-dot line 10 between the scaffold 1 and a designated safe area 11 adjacent the building 3. The apparatus 9 comprises a scaffold safety screen material 12 which is initially in the form of a roll mounted on a spindle 13. The scaffold safety screen material is in the form of 25mm x 25mm square netting but other configurations of netting may be used and/or other suitable sheet materials can of course be used, for example continuous sheets of transparent plastic material. The spindle 13 is mounted on the roof 7 of the building 3 and forms part of a deployment means for deploying the sheet material 12 from the spindle over the face 2 of the building 3. The deployment means also comprises a cantilever arm 25 which is secured to the roof 7 at one end and overhangs the face 2 at its remote end 14. The remote end 14 is provided with a guide means in the form of a roller 15 which is spaced from the building face 2 towards the safe area 11.

With reference to Figure 2, in one arrangement the spindle 13 comprises a rotatable shaft 17 on which a roll of sheet material is mounted. The shaft 17 is mounted on a support frame 18 which is provided with feet 19 for temporarily securing the spindle 13 to the roof 7 by means of chemical anchor eye bolts 20, namely eye bolts with a chemical fixature. A drive means in the form of a crank handle 21 is provided for rotating the shaft 17. The crank handle 21 is connected to the shaf t 17 via a gearbox 22 having suitable brake and clutch means (not shown) for controlled deployment of the sheet material 12.

In use, when it is desired to erect the scaffold 1 on the face 2 of the building a safety screen is positioned along line 10 according to the following method.

The spindle 13 is temporarily secured to the roof 7 in a position corresponding to the face 2 which is to be provided with a scaffold safety screen. The remote end 14 of the cantilevered arm 25 is positioned in a cantilevered position which overhangs the face 2 by an amount corresponding to a desired space between the safety screen and the face 2 in which the scaffold is to be erected. A roll of safety screen sheet material 12 is mounted on the spindle 13 and a free end of the sheet material is positioned over the roller 15. The sheet material is then deployed from the roll under controlled operation using the crank handle 21.

The sheet material 12 is lowered under its own weight or with additional weights added to the free end thereof for additional stability. In addition or alternatively, ropes or other control lines can be attached to the free end of the 9 sheet material 12 to control its descent further from the ground so as to avoid flapping or other undesired movement. The sheet material 12 is lowered such that the free end thereof passes over the respective ends of the positioning means 16 so as to prevent interference of the sheet material with the protrusions 8.

once the free end of the sheet material 12 reaches the ground floor level of the building 3, the sheet material 12 is secured to the building 3 at the roof level and can be secured to the building at a lower level to prevent undesirable movement thereof. The sheet material remaining on the spindle 13 can be parted from the deployed sheet material and the spindle removed.

When it is necessary to provide a scaffold safety screen of a width greater than that of the sheet material 12 two or more rolls of sheet material can be deployed from adjacent spindles 13 aligned in side by side relation along the building face that is to be covered. In this way its is also possible to adapt the spindles 13 to operate in unison so that the respective sheets are deployed simultaneously. When more than one sheet is used in this way the respective sheets are joined together along their adjoining edges, either during deployment or once they are fully deployed.

Alternatively, the respective sheets may be deployed in an overlapping manner as shown in Figures 3a and 3b. In Figures 3a and 3b, three spindles 13 are each arranged parallel to a respective face 2 of an angled facade of a structure 1. The length of the spindles!3 and hence width dimension of the respective sheet material is slightly less than the width dimension of the respective faces 2. Two secondary spindles 34 of shorter length than the spindles 13 are positioned in an overlapping manner with respect to respective adjacent ends of the spindles 34. The secondary spindles 34 are spaced apart from the spindles 13 in a direction away from the respective faces 2 and are mounted in an elevated position with respect to the spindles 13. The sheet material mounted on the spindles 13 can be deployed first in the above described manner followed by the sheet material on the secondary spindles 34 so as to cover the gaps created between the sheet material deployed from the spindles 13. Alternatively the sheet material on spindles 13 and 34 can be deployed simultaneously so as to completely cover the faces 2 in a single operation. In this way it is possible to cover more irregular shaped structures, for example those having curved faces, and corners of adjoining faces, particularly when the corners are angled as in a pentagonal shaped building for example.

is Once the safety screen sheet material has been deployed the scaffolding 1 is erected. The scaffolding is erected layer by layer between the ground floor level and a desired higher level. The sheet material is secured to the scaffold 1 after each level of scaffold has been erected. When the sheet material has been secured to a particular level of the scaffold the positioning means below that level can be removed. When the scaffold is to be dismantled the sheet material is unsecured from the level of scaffold that is next to be dismantled.

The sheet material is secured to the scaffold using any manner of suitable connection means such as elasticated ties 31, so called zip ties or cable ties. In this regard, scaffold safety screen support tubes 4G may be formed with T sections 30 at their ends as shown in Figure 4 to provide a secure connection with the sheet material netting. The support tubes 46 and/or positioning means 16 may be formed of aluminium so as to advantageously reduce their weight. The elasticated ties 31 may take the form shown in Figures 5a and 5b with a ringlet 32 at one end an a T-section 33 at the other end for threading through the ringlet 32 to secure the sheet material netting to an adjacent T-section 30.

With reference now to Figure G, in order to facilitate movement of relatively long articles, scaffold components and materials etc around the corners of the erected scaffold the positioning means 16 can be extended outwards at the corner of the structure to increase the distance between the safety screen and the structure in the region of the safety screen.

As shown in Figure 6 the positioning means 16 at a corner 35 of the structure have a greater length than the positioning means remote from the corner. This provides a turning area 36 of increased radius.

The scaffold shown in Figures 7a and 7b is provided with a cantilevered loading platform 37 for material handling. The loading platform 37 can also function as a "protection fan". In the arrangement of Figures 7a and 7b the angled support protrusion 8 has a length greater than that of the positioning means 16 such that the loading platform 37 is spaced further from the structure than the sheet material safety screen 10 above and below it (respectively to the top and bottom of the drawing of Figure 7a). In this arrangement the safety screen is provided with an opening in the region above the platform 37 for access purposes. Safety screen sheet material surrounds the overhanging sides 38 of the loading platform but is open on its side 39 closest to the structure.

The scaffold shown in Figure 8 comprises a suspended platform 40 which is suspended on the underside 41 of a structure, for example a bridge, culvert or elevated walkway. The safety screen surrounds the platform 40 on all sides having an open top 42 for access to the underside 41 of the structure. The safety screen of Figure 8 is particularly advantageous when the suspended platform 40 is provided over water since it will allow dropped articles etc to be easily recovered.

With reference to Figures 9a and 9b, the remote ends of the positioning means 16 are each provided with a guide means in the form of a T-section end 47. In Figure 9a the T-section end 47 of a positioning means 16 is provided with a crescent shaped cross-section end 43. In Figure 9b the T-section end 47 is provided with an elongate roller 44 which is rotatable on a shaft supported at both its ends by a V-shaped element 45 at the end of the positioning means 16. The profile of the crescent shaped crosssection end 43 and the roller 44 reduce friction when in contact with the sheet material. This reduces abrasion of the sheet material which can cause the sheet material to rip and become detached from the scaffold. A friction reducing coating such as Teflon (Registered Trade Mark) can be applied to the end 43 or roller 44 so as to further reduce friction.

Accordingly, it will be seen from the foregoing that 20 during erection and dismantling the scaffold is completely contained within a safety screen of sheet material. moreover, since the safety screen is secured directly to the scaffold there is no requirement for any additional protective structure beyond the line 10 of safety screen. Furthermore since the sheet material netting can be readily secured to the scaffold using known connectors the installation of the safety screen is a simple procedure.

It will be appreciated that the embodiment illustrated shows an application of the invention in one form only for the purpose of illustration. In practice, the invention may be applied to many different configurations, the detailed embodiments being straightforward for those skilled in the art. to implement.

For example, the sheet material netting can be hexagonal, triangular, rectangular, octagonal, pentagonal or other polygonal netting or any other shape suitable for use as a scaffold safety screen material. The netting can be single strand, tied or heat welded. The netting can also be multi-strand woven into a single strand. The netting can be polypropylene, nylon or other suitable netting material. The netting can be coloured or opaque or completely, transparent\translucent.

The present invention also allows a second safety screen to be secured directly to the scaffold in accordance with the prior art method discussed herein. This allows a net like safety material to be used for the first safety screen and a Aecj'n.-ececk continuous sheet material such as Monarflex krade Mark) to be used for the second safety screen. In this way, graphics such as advertisements can be applied to the second safety screen without being obstructed from view by the first safety screen.

Furthermore, in alternative embodiments, the positioning 20 means 16 can remain in place and the safety screen material can be secured to the ends 47 of the positioning means 16 instead of or in addition to the scaffold. In this way, the positioning means provide a scaffold safety screen support means. Moreover, the positioning means 16 can be part of the scaffold 1.

Claims

CLAIMS:-

1. Apparatus for providing a scaffold safety screen; said apparatus comprising:- a scaffold safety screen sheet material; deployment means for deploying said sheet material from an elevated position towards a base of a structure to be scaffolded so as to provide a scaffold saEety screen over an area of said structure.

2- Apparatus according to claim 1 wherein said deployment means comprises spacer means for deploying said sheet material from a position spaced apart from said area of said structure.

3. Apparatus according to claim 2 wherein said spacer means comprises cantilever means.

4. Apparatus according to claim 3 wherein said cantilever means comprises a cantilever arm having a guide means at a remote end thereof for guiding said sheet material over said arm.

5. Apparatus according to any one of claims 1 to 4 wherein said sheet material is provided as a roll and said deployment means comprises a spindle for deploying said sheet material from said roll.

6. Apparatus according to claim 5 wherein said spindle comprises drive means for deploying said sheet material.

7. Apparatus according to any preceding claim wherein said sheet material comprises a net like sheet material.

8. Apparatus according to any one of claims 1 to 6 wherein said sheet material comprises a substantially continuous sheet.

9. Apparatus according to ary preceding claim wherein said deployment means is provided with connection means for connection to said structure.

10. Apparatus according to any preceding claim further comprising sheet material support means for supporting said sheet material relative to said structure.

11. Apparatus according to claim 10 wherein said sheet material support means comprises part of an erected scaffold.

12. Apparatus according to any preceding claims further comprising sheet material positioning means for positioning said sheet material relative to structure.

13. Apparatus according to claim 12 wherein said sheet material positioning means is provided with positioning guide means at remote ends thereof.

14. A method of providing a scaffold safety screen; said method comprising the steps of:

(a) positioning a scaffold safety screen sheet material at an elevated position on a structure to be scaffolded; and (b) deploying said sheet material from said elevated position towards a base of said structure to provide a scaffold safety screen over an area of said structure.

15. A method according to claim 14 wherein step (a) comprises the further step of positioning a free end of said sheet material at a position spaced apart from said area of said structure.

1G. A method according to claim 15 wherein said further step comprises positioning said free end at a cantilevered position spaced apart from said structure.

17. A method according to claim 16 wherein said step of positioning said free end of said sheet material at a cantilevered position comprises the step of positioning said free end over a guide means provided at the remote end of a cantilevered arm.

18. A method according to any one of claims 14 to 17 wherein said sheet material is provided as a roll and said deploying step comprises the step of rotating said roll to deploy said sheet material from said roll.

19. A method according to any one of claims 14 to 18 further comprising a step (c) of securing said sheet material to a sheet material support means -provided between said structure and said sheet material.

20. A method according to claim 19 wherein said sheet material is secured to said sheet material support means during erection of a scaffold between said sheet material and said structure.

21. A method according to claim 20 wherein said sheet material is secured to said sheet material support means in steps such that said sheet material is secured to said sheet material support structure up to a level of scaffold in the process of being erected.

22. A method according to any one of claims 19 to 21 wherein said step of securing said sheet material to a sheet material support means comprises securing said sheet material to said scaffold.

23. Apparatus substantially as hereinbefore described and/or with reference to the accompanying drawings.

24. A method substantially as hereinbefore described and/or with reference to the accompanying drawings.