AU2015203534A1 - A construction screen system - Google Patents

Abstract

Abstract A construction screen system is described that comprises a screen device configured to span at least one floor of a building under construction, the screen device arranged 5 to be moved progressively upwardly of the building under construction during use. The screen device includes at least one supporting member arranged to extend substantially vertically during use, the at least one supporting member includes a first set of spaced first apertures disposed longitudinally along the at least one supporting member and a second set of spaced second apertures disposed longitudinally along 10 the at least one supporting member, and each first aperture is spaced a defined vertical distance from a second aperture. The system also includes at least one bracket assembly connectable to a floor portion of a floor of the building, each bracket assembly arranged to engage a supporting member and thereby retain the screen device relative to the building under construction whilst permitting the screen device to 15 move upwardly relative to the building. The bracket assembly includes a first pawl member pivotable between a first position wherein the first pawl member is not engageable with a first aperture and a second position wherein the first pawl member is engageable with a first aperture, and a second pawl member pivotable between a first position wherein the second pawl member is not engageable with a second 20 aperture and a second position wherein the second pawl member is engageable with a second aperture. The first and second pawl members are biased towards the second position and the first and second apertures are offset from each other such that the first and second pawl members alternately engage and disengage with a respective first or second aperture as the screen device is moved upwardly of the floor during use. 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 ----------

Description

1 A CONSTRUCTION SCREEN SYSTEM Field of the Invention 5 The present invention relates to a construction screen system for use with a building under construction, for example because the building is new or the building is in existence and undergoing renovation. Background of the Invention 10 It is known to provide a construction screen system for protecting people during the initial construction stages of a building when external walls have not yet been constructed and sides of the building floors are therefore open. Such systems are generally of the type including a screen device of generally flat configuration that 15 typically spans one or more floors of the building, a retaining mechanism for retaining the screen device adjacent the building, and a lifting mechanism arranged to raise and lower the screen device as required during use. Typically, the system includes multiple screen devices so that the entire perimeter of at least one floor of the building under construction is protected, and workers and debris on the building floor are prevented 20 from falling as work continues on the floor. However, such construction screen systems tend to be relatively heavy and expensive. Summary of the Invention 25 In accordance with an aspect of the present invention, there is provided a construction screen system comprising: a screen device configured to span at least one floor of a building under construction, the screen device arranged to be moved progressively upwardly of the 30 building under construction during use, the screen device including at least one supporting member arranged to extend substantially vertically during use, the at least one supporting member including a first set of spaced first apertures disposed longitudinally along the at least one supporting member and a second set of spaced second apertures disposed longitudinally along the at least one supporting member, 35 and each first aperture being spaced a defined vertical distance from a second aperture; at least one bracket assembly connectable to a floor portion of a floor of the 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 2 building, each bracket assembly arranged to engage a supporting member and thereby retain the screen device relative to the building under construction whilst permitting the screen device to move upwardly relative to the building, the bracket assembly including a first pawl member pivotable between a first position wherein the first pawl member is 5 not engageable with a first aperture and a second position wherein the first pawl member is engageable with a first aperture, and a second pawl member pivotable between a first position wherein the second pawl member is not engageable with a second aperture and a second position wherein the second pawl member is engageable with a second aperture; 10 wherein the first and second pawl members are biased towards the second position and the first and second apertures are offset from each other such that the first and second pawl members alternately engage and disengage with a respective first or second aperture as the screen device is moved upwardly of the floor during use. 15 In an embodiment, the first and second sets of apertures are provided on the same supporting member. In an embodiment, at least one supporting member includes a flange and the flange is provided with the first and/or second sets of apertures. Each supporting member may 20 be an I-section member. In an embodiment, each bracket assembly includes first and second wing members that extend behind the flange and thereby retain the associated supporting member relative to the bracket assembly. At least one of the first and second wing members 25 may be removable so as to enable the supporting member to be engaged by the bracket member. The system may include an adjustable prop assembly arranged to connect a floor portion of the building to the screen device and thereby brace the screen device to the 30 building. In an embodiment, the adjustable prop assembly includes first and second externally threaded portions and an internally threaded prop member engaged with the first and second threaded portions, wherein rotation of the prop member in a first rotational 35 direction causes elongation of the prop assembly, and rotation of the prop member in a second opposite rotational direction causes contraction of the prop assembly. 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 3 In an embodiment, the adjustable prop assembly includes a prop connector arranged to engage with at least one first and/or at least one second aperture. In an embodiment, the prop connector includes at least one projection arranged to 5 engage with a first or second aperture when the projection is received in a first or second aperture and the length of the prop assembly is extended. In an embodiment, each of the first and second pawl members is rotatable about a respective pivot connection and each of the first and second pawl members is biased 10 towards the second position by configuring the first and second pawl members such that the centre of gravity of each of the first and second pawl members is disposed between the respective pivot connection and the screen device. In an embodiment, the bracket assembly includes an elongate fixing member fixable to 15 a floor portion of a floor of the building, and an engagement assembly connected to the fixing member and arranged to retain the screen device relative to the building under construction whilst permitting the screen device to move upwardly relative to the building. 20 The construction screen system may comprise a plurality of screen devices and associated bracket assemblies. In an embodiment, each screen device may include two associated bracket assemblies, each bracket assembly arranged to engage with a respective supporting 25 member by alternate engagement and disengagement of the first and second pawl members with a respective first or second aperture as the screen device is moved upwardly of the floor during use. In an embodiment, each screen device is arranged to span multiple floors of a building 30 under construction. Brief Description of the Drawings The present invention will now be described, by way of example only, with reference to 35 the accompanying drawings, in which: Figure 1 is a diagrammatic perspective view of a construction screen system in accordance with an embodiment of the present invention; 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 4 Figure 2 is a diagrammatic perspective view showing a portion of the construction screen system shown in Figure 1; Figure 3 is a diagrammatic perspective view of a bracket assembly of the construction screen system shown in Figures 1 and 2; 5 Figure 4 is a diagrammatic side view of the bracket assembly shown in Figure 3; Figure 5 is a diagrammatic plan view of the bracket assembly shown in Figures 3 and 4, with a prop member of the bracket assembly removed; Figure 6 is a diagrammatic perspective view of an engagement assembly of the 10 bracket assembly shown in Figures 3 to 5; Figure 7 is a diagrammatic perspective view of the engagement assembly shown in Figure 6 with some features of the engagement assembly removed; Figure 8 is a diagrammatic perspective view of an upper portion of a prop assembly of the bracket assembly shown in Figures 3 to 5; and 15 Figure 9 is a diagrammatic view of a hoist for use in raising and lowering a screen device of the construction screen system relative to a building during use. Description of an Embodiment of the Invention 20 Referring to the drawings, in Figures 1 and 2 a construction screen system 10 is shown during use in relation to a building under construction 12, in this example a new building that is constructed by progressively constructing floors of the building and moving upwards when each floor is sufficiently complete. 25 In the present example, the building under construction 12 is of a type wherein each floor is defined by a concrete slab 14 and the concrete slabs are held in position relative to each other using supporting steel work 16, although it will be understood that any building of the type wherein multiple stories are constructed is envisaged. 30 The construction screen system 10 includes a structural frame 18 that in this example includes first and second vertical supporting members 20, 22 of I-section configuration, and several connecting horizontal supporting members 24. In this example, the vertical and horizontal supporting members 20, 22, 24 are formed of steel material, although any other suitable material is envisaged. 35 The construction screen system 10 also includes a screen device 30 connected to and held by the structural frame 18, the screen device 30 including a screen frame 32 that 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 5 in this example connects to and holds multiple adjacently disposed mesh panels 34, although it will be understood that a single mesh panel may alternatively be used. In this example, the screen frame 32 and mesh panels 34 are formed of lightweight 5 steel material and the mesh panels 34 are approximately 9 metres wide, although it will be understood that any suitable material and dimensions are envisaged. It will be understood that although Figure 1 shows a construction screen system 10 that includes one screen device 30 that is arranged to cover a width of approximately 10 9m, in practice multiple such screen devices 30 and associated structural frames 18 would be provided in order to completely cover the perimeter of each building floor intended to be rendered safe by the system 10 as construction work on the floor is performed. 15 It will also be understood that in the present embodiment the construction screen system 10 covers approximately three floors of the building 12 under construction, although it will be understood that other construction screen systems 10 are envisaged that cover more or less than three floors. 20 The construction screen system 10 also includes several bracket assemblies 36 that serve to fix the screen device 30 to slabs 14 of the building 12 under construction. The bracket assemblies 36 also serve to hold the screen device 30 adjacent the slabs 14 whilst permitting the screen device 30 to move in a controlled way relative to the slabs 14 upwards or downwards of the slabs 14. 25 As shown more particularly in Figures 2 to 5, each bracket assembly 36 includes an elongate fixing member 40, in this example of square hollow section (SHS) type, that is fixed to a concrete slab 14 using fixing lugs 41 and, for example, preinstalled threaded rods or concrete anchors. 30 An end of the fixing member 40 adjacent the outer edge of the slab 14 is fixed to an engagement assembly 42 shown in more detail in Figures 3, 6 and 7, the engagement assembly 42 serving to engage with a vertical supporting member 20, 22 of the screen device 30, as described in more detail below. 35 The bracket assembly 36 also includes a prop assembly 44 that connects during use between the fixing member 40 and a vertical supporting member 20, 22, thereby 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 6 bracing the screen device 30 to the fixing member 40. As best shown in Figures 3, 5 and 7, the engagement assembly 42 includes first and second parallel side plates 48, 49 connected to the fixing member 40, and first and 5 second cross members 50, 52 that extend between the first and second side plates 48, 49. Figure 7 shows the engagement assembly 42 with some components removed so that internal components can be seen with more clarity. A shaft 54 extends through the first io and second side plates 48, 49, the shaft 54 serving to pivotably mount first and second pawl members 56, 58. The pawl members 56, 58 are engageable in respective first and second apertures 60, 62 formed in a flange 64 of a vertical supporting member 20, 22. 15 As best shown in Figures 2, 3 and 7, each of the vertical supporting members 20, 22 has a first set of first apertures 60 disposed longitudinally along the vertical supporting member 20, 22, and a second set of second apertures 62 also disposed longitudinally along the vertical supporting member 20, 22, with the first and second sets of apertures horizontally spaced from each other. The first and second sets of apertures 20 60, 62 are also offset from each other such that each of the first and second apertures 60, 62 is disposed at a different height, with each first aperture 60 disposed at a height that is between the heights of adjacent second apertures 62, and each second aperture 62 disposed at a height that is between the heights of adjacently disposed first apertures 60. 25 Each of the pawl members 56, 58 is biased towards the flange 64, in this example by shaping the pawl members 56, 58 such that the centre of gravity of each pawl member 56, 58 is between the shaft 54 and the flange 64. In this way, when a first or second pawl member 56, 58 is aligned with a respective first or second aperture 60, 62, the 30 first or second pawl member 56, 58 will be received in and thereby engage with the first or second aperture 60, 62. Accordingly, as the screen device 30 and thereby the flange 64 of each vertical supporting member 20, 22 moves upwards during use, the first and second pawl members 56, 58 will alternately engage and disengage with respective first and second apertures 60, 62, and it will be appreciated that in this way 35 the screen device 30 will be restrained from falling should a failure occur with the lifting device that is used to move the screen device 30 upwards. 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 7 It will also be appreciated that since the first and second sets of apertures 60, 62 are offset from each other in a vertical direction, should a failure occur with the lifting device which causes the screen device 30 to fall, the maximum distance that the screen device 30 will actually fall will be half the distance between adjacent apertures 5 in the first or second set of apertures 60, 62. As a consequence, it is possible to fabricate the screen device 30 using a lighter structural frame 18 than would be possible if only a single set of apertures were present. This is because for a single set of apertures, the thickness of the flange 64 would need to be increased in order to withstand forces that would be exerted on the flange by the screen device falling by a 10 distance equal to the spacing between adjacent apertures. As best seen in Figure 6, the engagement assembly 42 also includes a first bracket 66 fixed to the first side plate 48, and a first wing member 68 connected to the first bracket 66 that extends parallel to the flange 64 on a side of the flange 64 opposite to the fixing 15 member 40. Similarly, a second bracket 70 and connected second wing member 72 extending parallel to the flange 64 on a side of the flange 64 opposite to the fixing member 40 are provided, although unlike the first bracket 66 which is permanently fixed to the first side 20 plate 48, the second bracket 70 is not permanently fixed to the second side plate 49 but is instead connectable to and disconnectable from the second side plate 49 using bolt 74 and nut 76. The first and second wing members 68, 72 serve to hold the flange 64 between the 25 first and second wing members 68, 72 and the side plates 48, 49 such that, during use, movement of the flange 64 and thereby the vertical supporting member 20, 22 in a generally horizontal direction is restrained, whilst permitting the flange 64 to move in a generally vertical direction. The second fixing bracket 70 and the second wing member 72 are removable from the engagement assembly 42 so as to enable a vertical 30 supporting member 20, 22 of the screen device 30 to be received in the engagement assembly 42 and subsequently retained relative to the engagement assembly 42 by connecting the second fixing bracket 70 and the second wing member 72 to the second side plate 49 using the bolt 74 and nut 76. 35 As shown more particularly in Figures 3, 4 and 8, the prop assembly 44 includes an elongate prop member 80 that includes an internal threaded portion engageable with first and second threaded portions 82, 84 such that rotation of the prop member 80 in a 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 8 first rotational direction relative to the threaded portions 82, 84 causes the length of the prop assembly 44 to increase, and rotation of the prop member 80 in a second opposite rotational direction relative to the threaded portions 82, 84 causes the length of the prop assembly 44 to decrease. 5 The prop assembly 44 also includes a bottom bracket 86 that is pivotably connected to the first threaded portion 82 and fixed to the fixing member 40, and a prop connector 88 having a top bracket portion 90 pivotably connected to the second threaded portion 84 and a connecting plate 92 provided with several projections 94. The projections 94 10 are configured so as to be engageable with the first and second apertures 60, 62 in the flange 64 when the projections 94 are received in the first and second apertures 60, 62 and moved upwardly relative to the apertures. For this purpose, the projections are in this example generally L-shaped, although other configurations that achieve engagement between the connecting plate 92 and the flange 64 are envisaged. 15 It will be understood that during use when the screen device 30 is raised to the desired location relative to the building 12 under construction, in order to secure the screen device 30 relative to the building 12 the prop assembly 44 is pivoted about the bottom bracket 86 to bring the prop connector 88 towards the flange 64. The prop member 80 20 is then rotated to increase or decrease the length of the prop assembly 44 so that the projections 94 are received in the first and second apertures 60, 62. When the projections 94 are received in the apertures 60, 62, the prop assembly 44 is lengthened in order to engage the projections 94 with the apertures 60, 62 and thereby form a strong connection between the screen assembly 30 and the fixing member 40. 25 A suitable lifting assembly in the form of a hoist 98 is shown in Figure 9, the hoist 98 including a hoist cable 100 and a lifting mechanism 102 that is arranged to controllably winch the hoist cable 100 towards or away from the lifting mechanism 102. 30 The hoist cable 100 is connected to the screen device at any suitable location and the hoist 98 is used to controllably raise or lower the screen device 30 relative to the building 12 under construction. During use, sufficient screen devices 30 are provided to cover the entire perimeter of a 35 floor of a building 12 under construction, and the required number of bracket assemblies 36 are fixed to the slabs 14 of the floors to be covered by the screen devices, for example using pre-installed threaded rods. The screen devices 30 are 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 9 then fixed to the hoist cable 100 of the hoist 98, for example by attaching the hoist cable to lifting lugs (not shown) on the structural frames 18 of the screen devices 30, and the screen devices 30 are raised by the hoist 98 until the screen devices 30 are disposed at a height suitable to cover several floors of the building 12. When the 5 screen devices 30 are disposed at this position, the second bracket 70 and associated wing member 72 are detached from the engagement assembly 42, and flanges 64 of the vertical supporting members 20, 22 are received in the engagement assembly 42 and fixed in the engagement assembly 42 by re-attaching the second bracket 70 and associated wing member 72 to the engagement assembly 42. 10 The prop assemblies 44 of the bracket assemblies 36 are then engaged with the first and second apertures 60, 62 of the flanges 64 by disposing each connecting plate 92 adjacent a flange 64 and rotating the prop member 80 until the projections 94 are received in the first and second apertures 60, 62 and engage with the apertures 60, 62. 15 After work is complete on the floors covered by the screen devices 30, the hoist 98 is detached from the structural frames 18, moved to a higher floor of the building 12, and re-attached to the structural frames 18. The prop assemblies 44 are then released from engagement with the flanges 64, and the lifting mechanism 102 activated so as to 20 raise the structural frames 18 and thereby the screen devices 30 relative to the building 12. As the screen devices 30 move upwards, the first and second pawl members 56, 58 alternately engage and disengage with respective first and second apertures 60, 62 in a ratchet like manner. In this way, should the screen devices 30 fall, the fall will be restrained by engagement of one of the first or second pawl members 56, 58 of each of 25 the engagement assemblies 42 in a respective first or second aperture 60, 62. When the screen devices 30 have been raised to a desired height, the prop assemblies 44 of the bracket assemblies 36 are again engaged with first and second apertures 60, 62 of the flanges 64 by disposing each connecting plate 92 adjacent a 30 flange 64 and rotating the prop member 80 until the projections 94 are received in the first and second apertures 60, 62 and engage with the apertures 60, 62 This process continues until work has been completed on all floors of the building 12 under construction. 35 In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 10 implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country. 10 Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention. 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15

Claims (15)

1. A construction screen system comprising: a screen device configured to span at least one floor of a building under 5 construction, the screen device arranged to be moved progressively upwardly of the building under construction during use, the screen device including at least one supporting member arranged to extend substantially vertically during use, the at least one supporting member including a first set of spaced first apertures disposed longitudinally along the at least one supporting member and a second set of spaced 10 second apertures disposed longitudinally along the at least one supporting member, and each first aperture being spaced a defined vertical distance from a second aperture; at least one bracket assembly connectable to a floor portion of a floor of the building, each bracket assembly arranged to engage a supporting member and thereby 15 retain the screen device relative to the building under construction whilst permitting the screen device to move upwardly relative to the building, the bracket assembly including a first pawl member pivotable between a first position wherein the first pawl member is not engageable with a first aperture and a second position wherein the first pawl member is engageable with a first aperture, and a second pawl member pivotable 20 between a first position wherein the second pawl member is not engageable with a second aperture and a second position wherein the second pawl member is engageable with a second aperture; wherein the first and second pawl members are biased towards the second position and the first and second apertures are offset from each other such that the first 25 and second pawl members alternately engage and disengage with a respective first or second aperture as the screen device is moved upwardly of the floor during use.

2. A construction screen system as claimed in claim 1, wherein the first and second sets of apertures are provided on the same supporting member. 30

3. A construction screen system as claimed in claim 1 or claim 2, wherein at least one supporting member includes a flange and the flange is provided with the first and/or second sets of apertures. 35

4. A construction screen system as claimed in claim 3, wherein at least one supporting member is an I-section member. 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 12

5. A construction screen system as claimed in claim 3 or claim 4, wherein each bracket assembly includes first and second wing members that extend behind the flange and thereby retain the associated supporting member relative to the bracket assembly. 5

6. A construction screen system as claimed in claim 5, wherein at least one of the first and second wing members is removable so as to enable the supporting member to be engaged by the bracket member. 10

7. A construction screen system as claimed in any one of the preceding claims, comprising an adjustable prop assembly arranged to connect a floor portion of the building to the screen device and thereby brace the screen device to the building.

8. A construction screen system as claimed in claim 7, wherein the adjustable 15 prop assembly includes first and second externally threaded portions and an internally threaded prop member engaged with the first and second threaded portions, wherein rotation of the prop member in a first rotational direction causes elongation of the prop assembly, and rotation of the prop member in a second opposite rotational direction causes contraction of the prop assembly. 20

9. A construction screen system as claimed in claim 7 or claim 8, wherein the adjustable prop assembly includes a prop connector arranged to engage with at least one first and/or at least one second aperture. 25

10. A construction screen system as claimed in claim 9, wherein the prop connector includes at least one projection arranged to engage with a first or second aperture when the projection is received in a first or second aperture and the length of the prop assembly is extended. 30

11. A construction screen system as claimed in any one of the preceding claims, wherein each of the first and second pawl members is rotatable about a respective pivot connection and each of the first and second pawl members is biased towards the second position by configuring the first and second pawl members such that the centre of gravity of each of the first and second pawl members is disposed between the 35 respective pivot connection and the screen device.

12. A construction screen system as claimed in any one of the preceding claims, 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15 13 wherein the bracket assembly includes an elongate fixing member fixable to a floor portion of a floor of the building, and an engagement assembly connected to the fixing member and arranged to retain the screen device relative to the building under construction whilst permitting the screen device to move upwardly relative to the 5 building.

13. A construction screen system as claimed in any one of the preceding claims, comprising a plurality of screen devices and associated bracket assemblies. 10

14. A construction screen system as claimed in any one of the preceding claims, wherein each screen device includes two associated bracket assemblies, each bracket assembly arranged to engage with a respective supporting member by alternate engagement and disengagement of the first and second pawl members with a respective first or second aperture as the screen device is moved upwardly of the floor 15 during use.

15. A construction screen system as claimed in any one of the preceding claims, wherein each screen device is arranged to span multiple floors of a building under construction. 20 66262471 (GHMatters) P97248.AU.1 STEVENS 25/06/15