AU2017203024A1 - An apparatus for raising a safety screen - Google Patents

Abstract

The present invention relates to a lifting bracket that can be used with an actuator for raising a safety screen, and a foot bracket that can be used for releasably connecting 5 the actuator to a building, and an apparatus for raising the safety screen. The term "safety screen", or variants thereof such as "screen" embraces a screen arranged about the perimeter of a high-rise building during construction, or any other screen that requires lifting to new elevations. 10 Figure 1. 9015226_1 (GHMatters) P103060.AU 5/05/17

Description

AN APPARATUS FOR RAISING A SAFETY SCREEN FIELD OF THE PRESENT INVENTION

The present invention relates to a lifting bracket that can be used with an actuator for raising a safety screen, and a foot bracket that can be used for releasably connecting the actuator to a building, and an apparatus for raising the safety screen. The term “safety screen”, or variants thereof such as “screen” embraces a screen arranged about the perimeter of a high-rise building during construction, or any other screen that requires lifting to new elevations.

BACKGROUND OF THE INVENTION

The construction of highrise buildings can be carried out using many different methods, one of which includes assembling formwork for casting concrete floors one above the next. Strict safety standards apply at all times during construction, and prior to the installation of an outer skin to the building safety screens are typically located about the perimeter of the building at levels occupied by construction crew to prevent the occupants and equipment from falling.

The screens may have any suitable height and width, and examples of heights in the range of 9 to 15 meters that span over 3 or 4 levels and have widths up to 5.4 meters are common. In any event, multiple screens can be interconnected using fasteners to increase the height and width of the screens depending the perimeter of the buildings and the workzone of the building.

As construction of the building progresses upward, traditionally the screens have been lifted by a worksite crane, however, this reduces the capacity of the crane to perform lifts relating to construction. To maximise availability of the crane, dedicated hydraulic lifting mechanisms have been devised to lift the screen from the buildings.

SUMMARY OF THE INVENTION

The present invention relates to a lifting bracket that can be releasably connected to an actuator for lifting a safety screen arranged about the perimeter of a building during construction, the screen having a rail formation that extends upwardly and engagement points that are spaced apart along the rail formation, the lifting bracket including: i. a coupling portion that can shift between a closed operative configuration in which the lifting bracket can move along and be retained on the rail formation, and an opened configuration in which the lifting bracket can be removed from the rail formation, wherein the coupling portion includes two bodies that move relative to each other to allow the coupling portion to shift between the opened configuration and the closed configuration, and ii. a lifting portion that is releasably connected to the coupling portion, and when the lifting bracket is in the closed operative configuration on the rail formation, the actuator is operable to move the lifting bracket upwardly along the rail formation so that the lifting portion can engage one of the engagement points to raise the screen to a new elevation about the building, following which the actuator can be operated to lower the lifting bracket along the rail formation to align the lifting portion with another of the engagement points disposed below for further raising of the screen.

The two bodies of the coupling portion may be interlocking when in the closed operative configuration by means of the two bodies of the coupling portion having interfitting formations that engage.

Throughout this specification, the term “actuator” embraces any suitable device including, for example, a pneumatic piston and cylinder mechanism, or a screw ram driven by an electric motor. Ideally, the actuator is a hydraulic piston and cylinder mechanism.

Suitably, the two bodies of the coupling portion can interlock without the use of fasteners, such as co-operating nuts and bolts. In other embodiments, the two bodies may be prevented from becoming unlocked, for example, by using a quick release pin, such as a lynch pin, a detent pin, a clevis pin, a hair pin, a split ring pin and so forth.

The two bodies of the coupling portion may include interfitting formations that interlock when the lifting portion is connected in an operative position to the coupling portion.

The two bodies of the coupling portion may include interfitting formations that releasably lock the coupling portion in the closed configuration, the interfitting formations may include: i) intermeshing elements on each of the respective bodies that engaged when the coupling portions are located in the closed configuration; and ii) a retaining mechanism that is operable to prevent the intermeshing formations from becoming disengaged when in the closed configuration.

The intermeshing elements may include one of the bodies of the coupling portion having a head and neck in which the neck connects the head to the body and the neck has a smaller cross-section than the head, and the other body of the coupling portion has a co-operating opening that is configured in the shape of and receive the head and neck when the planes of the bodies are moved into alignment.

The intermeshing elements may include a dovetail shaped member and a co-operating dovetail shaped opening that can be interfitted prior to the retaining device being operably fitted, by moving the intermeshing elements laterally to planes of the coupling portions.

The retaining mechanism may include each body having openings, and a locking pin that can be passed through the openings when the coupling portion is arranged in the closed configuration to prevent bodies of the coupling portion from moving out of a coplanar relationship.

The interlocking formations of the two bodies of the lifting portion may have openings that can receive a pin when the two bodies are arranged in the closed operative configuration.

The lifting portion may be pivotally connected to the coupling portion via the locking pin.

The bodies of the coupling portion may each have a retaining opening, preferably in the form of a slot, that face inwardly toward each other when the coupling portion is located in the closed configuration, and when in the closed configuration the openings can encapsulate at least part of the rail formation and move along the rail formation when driven by the actuator.

The present invention relates to an apparatus for elevating a safety screen arranged about the perimeter of a building during construction, the screen having a rail formation that extends upwardly and engagement points that are spaced apart upwardly on the rail formation, the apparatus includes: an actuator that can be releasably connected to the building; and a lifting bracket that includes: i) a coupling portion that can shift between a closed operative configuration in which the lifting bracket can move along and be retained on the rail formation, and an opened configuration in which the bracket can be removed from the rail formation, wherein the coupling portion includes two bodies that move relative to each other to allow the coupling portion to shift between the opened configuration and the closed configuration, and ii) a lifting portion that is releasably connected to the coupling portion, and when the bracket is in the closed operative configuration on the rail formation, the actuator is operable to move the lifting bracket upwardly along the rail formation so that the lifting portion can engage one of the engagement points to raise the screen to a new elevation, following which the actuator can be operated to lower the lifting bracket along the rail formation to align the lifting portion with another of the engagement points disposed below for further raising of the screen.

The apparatus may also include a foot bracket that is configured to releasably interconnect the actuator to the building.

The foot bracket may include a plate that is pivotally connected to the building, or a footing mounted to the building, via a first pivot connection, and pivotally connected to the actuator via a second pivot connection.

Either one or both of the first and second pivot connections may include the plate having an opening through which a pin is provided to allow the actuator to be released from the footing. Ideally, the pin is removable to allow the actuator to be releasably connected to the footing of the building and a further removable pin is provided to allow the actuator to be releasably connected to the foot bracket.

The first pivot connection may be in the form of a first opening in the plate of the foot bracket that defines a pivot axis, and the footing includes a pair of oppositely disposed openings and the plate can be located to align the first opening with the openings of the footing to allow a pin to pivotally connect the actuator to the plate.

The first pivot connection of the plate may include at least one cylindrical boss extending axially from the first pivot connection.

The second pivot connection may be in the form of a second opening of the plate that defines a pivot axis, and the actuator may include a yoke defined by two arms each with openings so that second opening of the base plate can be located to align the second opening with the openings of the yoke to allow a pin to pivotally connect the actuator to the plate.

The plate may include a locating bracket extending from the plate, the locating bracket being arranged to engage the footing and prevent the plate from pivoting below an operative position.

When in use, the actuator is operable to raise the lifting bracket, which in turn causes the lifting portion to engage the engagements points and lift the safety screen, and as the engagement points of the rail formation move upwardly, downwardly facing surface of the lower latch are contacted by the upwardly moving engagement points, causing the lower latch to pivot upwardly to allow the engagement points to progress past the lower latch, and the actuator is operable to lower the lifting bracket to cause the next engagement point above the lower latch to engage the lower latch and thereby enable the weight of the safety screen to transferred from the lifting bracket to the lower latch, wherein the lower latch is arranged to be prevented from pivoting below an operative position at which the lower latch supports the weight of the safety screen, and thereafter the actuator is operable to further lower the lifting bracket, whereby the lifting bracket progresses down the rail formation and when the engagement points contact a downwardly facing of the lifting portion, the lifting portion can pivot upward to allow the lifting bracket to move downward and along the rail formation to a new lower position on the rail formation.

The present invention also relates to a foot bracket that is configured to releasably interconnect the actuator to a footing that can be mounted to the building, wherein the foot bracket may include a plate which is pivotally connected to the footing via a first pivot connection and pivotally connected to the actuator via a second pivot connection.

Either one or both of the first and second connectors may include the base plate having an opening through which a releasable pin is provided to allow the actuator to be released from the mounting. Ideally, a releasable pin is provided to allow the actuator to be releasably connected to the mounting and a further releasable pin is provided to allow the actuator to be releasably connected to the actuator.

The foot bracket described in the paragraph immediately above may also include any one or a combination of the features of the foot bracket described throughout this specification.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the invention will now be described by way of example only with reference to the accompanying drawings, of which:

Figure 1 is a schematic exploded view of a removable apparatus including an actuator, a lifting bracket at an upper end of the actuator for engaging a rail formation of a screen and engagement points spaced along the rail formation for lifting the screen, and a foot bracket having a plate for interconnecting the actuator to a mounting member anchored to the building;

Figure 2 is a schematic side view of the apparatus shown in figure 1 in which the apparatus is located in an assembled position and the actuator is in the process of extending to lift the safety screen via the lifting bracket;

Figure 3 is a schematic side view of the apparatus shown in figure 2 in which the apparatus has lifted the safety screen to a new elevation where the screen is secured, and the actuator is in the process of retracting so that the apparatus can be used for further raising of the safety screen;

Figure 4 is a photograph showing a top and side perspective view of the lifting bracket having a coupling portion located in a closed configuration prior to being fitted to a rail formation of a safety screen, and a lifting portion for engaging the safety screen;

Figure 5 is a line drawing showing a plan view of the lifting bracket in figure 4, in which the coupling portion is located in a closed configuration and fitted to a rail formation of a safety screen so that the lifting portion can engage points of the safety screen;

Figure 6 is a plan view of the coupling portion in an opened configuration as shown in figure 5;

Figure 7 is an end view of the coupling portion in an opened configuration as shown in figure 6;

Figure 8 is a side view of the lifting portion of the lifting bracket shown in figures 4 and 5;

Figure 9 is a side view of the foot bracket shown in figures 1 to 3;

Figure 10 is a plan view of the foot bracket shown in figure 9;

Figure 11 is a photograph showing a top and side perspective view of the foot bracket shown in figure 9.

Figure 12 is a photograph showing a top view of the lifting bracket fitted to the actuator and the lifting portion located in an operative position relative to a rail formation of the safety screen; and

Figure 13 is a photograph of a removable apparatus as shown in Figure 1 and 2, the apparatus including an actuator, a lifting bracket at an upper end of the actuator for engaging a rail formation of the screen and engagement points spaced upwardly along the rail formation for lifting the screen, and a foot bracket having a plate for interconnecting the actuator to a mounting member anchored to the building.

DETAILED DESCRIPTION A preferred embodiment of the present invention will now be described with reference to the accompanying figures. The description includes reference numerals that are shown in the figures to help identify particular features. However, to maintain clarity of the figures not all of the reference numerals have been included in each figure.

With reference to the figures, the preferred embodiment relates to a removable apparatus that can be used to lift a safety screen about the perimeter of a multi-level or highrise building as construction of the building progresses upward. The safety screen is not illustrated in detail in the Figures, however, it will be appreciated that the safety screen may include and suitable framework, wire mesh, polymeric mesh, and paneling design to prevent people, tools and other debris from falling from the building.

The removable apparatus 20 for moving the safety screen includes a detachable actuator 21 that can be mounted to footing connected to the building, and a lifting bracket 22 includes a coupling portion 23 that can be shifted between an opened configuration, as shown in figures 6 and 7, and a closed configuration as in figures 4 and 5. The lifting bracket 22 also includes a lifting portion 24 in the form of a latch that is pivotally mounted to the coupling portion 23. The lifting portion 24 engages the bars 32 of a rail formation 31 that form part of the safety screen.

The opened and closed configurations of the lifting bracket 22 enable the lifting bracket 22 to be fitted to the rail formation 31 of the safety screen at any position along its length. Specifically, the coupling portion 23 of the lifting bracket 22 includes a pair of separable bodies 23A, 23B that form two cooperating halves that can be moved relative to each between the opened and closed configurations. Each body 23A and 23B of the coupling portion 23 is essentially a mirror image, save for intermeshing formations that help secure the coupling portion 23 in a closed configuration.

Each body 23A, 23B of the coupling portion 23 comprises a base plate 34 having a forward end, a rearward end, and an underneath face which is engaged by a ram 26 of the actuator 21. The forward end of the base plate 34 has a slot 27 having an opening that faces inwardly and toward the opening of other base plate 34. Each coupling portion 23 also has a right angled hinge mounting 28 that extends perpendicularly from an upper face of the base plate 34. As best seen in figures 6 and 7, the hinge mounting 28 includes a first flange 29 that extends along an inner aspect of the bodies 23A and 23B second flanged 30 that is located adjacent to the slot 27 of the base plate 34.

The two bodies 23A and 23B of the coupling portion 23 may be releasably interlocked in the closed operative configuration as shown in figures 4 and 5. In the case of figure 5, the coupling portion 23 is located in a locked configuration in which the slots 27 encapsulate a rail formation 31 of the safety screen. The rail formation 31 comprises two C- sections that are interconnected by engagement points in the formed by lifting bars 32 that extend between webs of C-sections.

Although not shown in the figures, the safety screen of the present invention may include any suitable mesh or barrier that is oriented vertically, and flooring extending horizontally from the mesh toward the building being constructed. To maintain the clarity of the drawings, the barrier, mesh and flooring is not shown in the figures, however, it will be understood that these components may be connected to the rail formation 31 using a suitable construction. Ideally the rail formation 31 of the safety screen extends along the height of the safety screen and the lifting bars 32 provide a suitable point for lifting and secure the safety screen at a suitable height.

The coupling portion 23 includes two interlocking formations 35 that enable the bodies 23A and 23B to be releasably interlocked. The two interlocking formations 35 include cooperating dovetails that interfit at a rear of the coupling portion 23, and a retainer mechanism that is operable to prevent the formations 35 from becoming disengaged.

The co-operating dovetails 35 include a dovetail shaped member extending from an inner side of one of the bodies 23B, and a cooperating dovetail shaped opening in the inner side of the other body 23A that receives the dovetail member when the two bodies 23A, 23B are located in the closed configuration. The cooperating dovetails 35 are configured to be interfitted by aligning the dovetails with the plane of the base plates 34 of the bodies 23A and 23B being non-coplanar, and moving the base plates 34 laterally to bring the base plates 34 into a coplanar position to interlock the dovetails 35 as shown in figure 1. Once the dovetails are engaged, the configuration of the dovetails 35 prevents the base plates 34 from moving apart.

The retainer mechanism is operable to prevent the dovetails 35 from becoming disengaged, and ideally prevents the base plates 34 from moving out of a co-planar alignment. For example, the retainer mechanism may be in the form of a pin 25 that interconnects the right angle hinge mountings 29. In the case of the preferred embodiment, the retainer mechanism is in the form of a pin 25 that has the dual purposes of interconnecting the bodies of the coupling portion 23 to maintain the bodies 23A and 23B in a co-planar alignment and in addition, the lifting portion 24 of the lifting bracket 22 is pivotally mounting on the pin 25.

The first flanges 29 of the coupling portion 23 include openings 33 that are aligned together when the coupling portion 23 is located in the closed position. When the two bodies 23A and 23B of the coupling portion 23 are located in the closed position and an opening 34 of the lifting portion (see figure 8) is aligned with the openings 33 of the first flanges 29, a pin 25 can be located in the openings 33, 34 to pivotally mount the lifting portion 24 to the hinge mounting 28 about the longitudinal axis of the pin 25. The pin 25 can be secured in position by means of a suitable lynch pin 52 (see figures 4 and 11).

The coupling portion 23 also include stop elements or shoulders 36 (see figure 6) at the forward end of the base plate 34 that extend inwardly toward each other. The shoulders 36 prevent the lifting portion 24 from pivoting below an operative position. Ideally, a longitudinal axis of the lifting portion 24 is oriented horizontally when in the operative position.

In use, the two halves of the coupling portion 23, shown in figures 6 and 7 are moved from a non-coplanar position to a planar position to interfit the dovetail formations 35 as described above. At the same time, the rail formation 31 of the safety screen is encapsulated by the slots 27, which is best shown in plan view in figure 5. The slots 27 are sized so that the coupling portion 23 can slide freely along the rail formation 31.

As shown in figure 8, a rear end of the lifting portion 24 is provided with a curved profile to allow the lifting portion 24 to be pivoted without engaging the base plate 34.

The lifting portion 24 is located between the first flanges 29 and the opening 34 of the lifting portion 24 is aligned with the openings 33 to allow the locking pin 25 to be manually positioned in the openings 33 and 34. A lynch pin 52 (see figures 4 and 11), can be located through an opening in the locking pin 25 to prevent the locking pin 25 from accidental removal and maintain the coupling portion 23 in a locked configuration.

Figure 4 is a photograph of the coupling portion 23 in a closed operative configuration, but without being installed on the rail formation 31 of the safety screen.

In order to shift the coupling portion 23 from that the closed configuration to the open configuration, the locking pin 25 must first be manually removed from the coupling portion 23, which then allows the rear end of the base plates 34 to be moved out of a coplanar orientation to release the dovetails 35, and in turn allow the forward end of the base plates 34 to be moved outwardly to release the rail formation 31 of the safety screen from the slots 27.

The actuator 21 may be releasably fitted to the building using any suitable means. In one example that is not illustrated in the drawings, the actuator 21 may be directly mounted to the building using a releasable faster.

According to the preferred embodiment, the apparatus 20 includes a foot bracket 40 that is operable to releasably interconnect the actuator 21 to an anchoring member 41 that is fastened to a floor of the building. The anchoring member 41 may be in the form two L-shaped members or C-shaped members oriented back-to-back and are attached to the floor of the building using, for example, mortar bolts or cast in fixings. The foot bracket 40 includes a plate 42 that is pivotally connected to the anchoring member 41 via a first pivot connection 43 and pivotally connected to the actuator 21 via a second pivot connection 44.

As can be seen in figures 1,2,3,9 and 11 the plate 42 has a rear lower portion that is located between the beams of the anchoring member 41 and a forward upper portion that is located above the anchoring member 41 when in use. Ideally, the first pivot connection 43 includes a cylindrical boss 55 that can be aligned and positioned between the openings 45 in the upright flanges of the anchoring member 41. When aligned, a securing pin 46 can be used to releasably connect the plate 42 to the anchoring member 41.

The plate 42 may also include stop limits 47 which engage the anchoring member 41 and prevent the plate 42 from pivoting downwardly between the beams of the anchoring member 41 beyond as desired operative position in which the actuator 21 is located above the anchoring member 42. The stop limits 47 may be in the form of shoulders projecting outwardly from the sides of the plate 42 that engage the upper edge of the beams of the anchoring member 41. Although not shown in the figures, the plate 42 may also include a further opening located forward and below the shoulders that align with further openings in the beams of the anchoring member 41 to prevent the plate 42 from pivoting relative to the anchoring member 42.

The forward upper portion of the plate 42 includes a nose extending toward the safety screen that includes a second pivot connection 44. Ideally, the lower end of the actuator 21 includes a yoke formation 53 that straddles either side of the nose of the plate 42 and includes openings 48 that can be aligned with the opening 49 of the second pivot connection 44 to allow a releasable pin 50 to be fitted, as best shown in figure 1.

The plate 42 may also include a handle 51 for moving the plate 42 and an abutment piece 54 projecting from the upper surface of the plate 42 on which the actuator 21 can abut to assist in locating the actuator 21.

Ideally, the ram of the actuator 21 is suitably in the form of a pair of arms 26 having openings 26A and an abutment surface 26B. When assembled, the arms 26 extend between the hinge mountings 28 of the lifting bracket 22 and the openings 26A receive the pin 25 and the abutment surface 26B can engage an underside of the lifting bracket 22. As can best be seen in figure 12, the arms 26 are spaced apart to accommodate the lifting portion 24 therebetween which is also attached to the pin 25.

The actuator 21 may be any suitable device including, for example, a hydraulic piston and cylinder mechanism, a pneumatic piston and cylinder mechanism, or a screw ram driven by an electric motor.

When the safety screen is in a stationary position, the weight of the safety screen is predominantly carried by a lower latch 60 (see figures 2 and 3) that is pivotally mounted to a forward most end of the anchoring member 41. The lower latch 60 is prevented from pivoting downwardly below a substantially horizontal orientation and includes an upwardly facing saddle 61 that receives the lifting bars 32 of the safety screen. Although not shown in the figures, additional push-pull props may be installed between the screen and the existing flooring to further stabilize the position of the safety screen relative to the perimeter of the building when the screen is stationary.

Figure 2 illustrates the apparatus in which the coupling portion 23 is in a closed operative position on the rail formation 31 of the safety screen. In use, as the lifting bracket 22 is moved upwardly along the rail by the actuator 21 in the direction of arrow A in figure 2, a saddle 36 on an upper face of the lifting portion 24 engages an under face of a lifting bar 32 immediately above and the weight of the screen is then transferred to the lifting portion 24. As the screen is lifted, the lifting bars previously supported on the lower latch 60 moves upwardly and clear of the lifting latch 60.

As the actuator 21 is operated into an extended position, the safety screen progresses upwardly and lifting bars located beneath the lower latch 60 engage a lower face of the latch 60 which pivots the latch 60 upwardly (as shown in Figure 3), allowing the safety screen to continue to move up. Ideally, when the actuator 21 reaches an extended position in which at least one, and preferably more than one, of the lifting bars 32 have progressed up and over the lower latch 60, and the lower latch 60 has pivoted back into a horizontal position.

Once the actuator 21 has reached its extended position and the lower latch 60 is located in a horizontal position, the actuator 21 can be operated to lower the safety screen to a new elevation at which of the lifting bar immediately above the lifting latch 60 engages the saddle of the lifting latch 60 to transfer the weight of the safety screen onto the lower latch 60. When the actuator 21 is retracted, the actuator 21 causes the lifting bracket 22 to move downwardly along the rail formation 31 of the safety screen which is enabled by the lifting portion 24 of the lifting bracket 22 pivoting upwardly about the locking pin 25, which is best seen in figure 3. While the lifting bracket 22 moves progressively downward, passing one or more lifting bars 32, the lifting bracket 22 is repositioned on a lower portion of the rail formation 31 ready for raising the safety screen again.

In order to elevate the safety screen to a higher position, the actuator 21 can be operated to cause the lifting portion 24 to engage a new lifting bar 32 that is located further down the screen than the lifting bar 32 previously engaged by the lifting portion 24. By operating the actuator to move the coupling 23 downwardly along the rail formation 31 and then upwardly, the safety screen attached to the rail formation 31 can be lifted and secured at new elevation as construction of the building progresses.

Moreover, one of the advantages of the preferred embodiment is that the apparatus 20 can be quickly connected and disconnected from the anchoring member 41 by shifting the coupling portion 23 between opened and closed configurations with little or no tools, and simply by removing a locking pin 25. In addition, the foot bracket 40 can also be quickly and easily removed by releasing the bottom pin 46. The apparatus can then be moved to an adjacent safety screen so it can be moved to a new height, and when required, the apparatus can be moved to a new floor of the building.

It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention.

Claims (21)

1. THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

   1. A lifting bracket that can be connected to an actuator for lifting a safety screen arranged about the perimeter of a building during construction, the screen having a rail formation that extends upwardly and engagement points that are spaced apart along on the rail formation, the lifting bracket including: i) a coupling portion that can shift between a closed operative configuration in which the lifting bracket can move along and be retained on the rail formation, and an opened configuration in which the lifting bracket can be removed from the rail formation, wherein the coupling portion includes two bodies that move relative to each other to allow the coupling portion to shift between the opened configuration and the closed configuration; and ii) a lifting portion that is releasably connected to the coupling portion; and when the lifting bracket is in the closed operative configuration on the rail formation, the actuator is operable to move the lifting bracket upwardly along the rail formation so that the lifting portion can engage one of the engagement points to raise the screen to a new elevation about the building, following which the actuator can be operated to lower the lifting bracket along the rail formation to align the lifting portion with another of the engagement points disposed below for further raising of the screen.
2. 2. The lifting bracket according to claim 1, wherein the two bodies of the coupling portion interlock when in the closed operative configuration by means of the two bodies of the coupling portion having interfitting formations that engage.
3. 3. The lifting bracket according to claim 2, wherein the interfitting formations include: i) intermeshing elements on each of the respective bodies that engaged when the coupling portions are located in the closed configuration; and ii) a retaining mechanism that is operable to prevent the intermeshing formations from becoming disengaged when in the closed configuration.
4. 4. The lifting bracket according to claim 3, when the coupling portion is in a closed configuration, the intermeshing elements and the retaining mechanism are operable to keep the bodies in a co-planar relationship.
5. 5. The lifting bracket according to claim 3 or 4, wherein the intermeshing elements include one of the bodies of the coupling portion having a head and neck in which the neck connects the head to the body and the neck has a smaller cross-section than the head, and the other body of the coupling portion has a co-operating opening that is configured to receive the head and neck when the planes of the bodies are moved into alignment.
6. 6. The lifting bracket according to any one of claims 3 to 5, wherein the intermeshing elements include a dovetail shaped member and a co-operating dovetail shaped opening that can be interfitted by moving the intermeshing elements laterally to planes of the coupling portions.
7. 7. The lifting bracket according to any one of claims 3 to 6, wherein the retaining mechanism includes each body having a flange with an opening, and a locking pin can be passed through the openings when the coupling portion is arranged in the closed configuration to prevent the bodies of the coupling portion from moving out of a coplanar relationship.
8. 8. The lifting bracket according to any one of claims 3 to 6, wherein the bodies of the coupling portion each include a base plate that are held in a co-planar relationship when located in the closed configuration and the interfitting formations forming part of the base plates.
9. 9. The lifting bracket according to any one of claims 1 to 8, wherein the lifting portion is pivotally connected to the coupling portion about a pivot axis defined by the locking pin.
10. 10. The lifting bracket according to any one of claims 1 to 9, wherein the lifting portion is pivotally connected to the coupling portion in which: i) the lifting portion pivots upwardly when the actuator is operated to lower the lifting bracket and a downwardly facing surface of the lifting portion moves over engagement points of the rail formation; and ii) a stop element prevents the lifting portion from pivoting downward when an upwardly facing side of the lifting portion engages the engagement points of the rail formation and the actuator moves the lifting bracket upward along the rail formation.
11. 11. The lifting bracket according to claims 1 to 10, wherein the bodies of the coupling portion each have a retaining opening that face inwardly toward each other when the coupling portion is located in the closed configuration, and when in the closed configuration the openings can encapsulate at least part of the rail formation and move along the rail formation when driven by the actuator.
12. 12. The lifting bracket according to claim 11 when appended to claim 8, wherein the retaining openings form part of the base plates of the bodies of the coupling portion.
13. 13. An apparatus for elevating the safety screen, wherein the apparatus includes: a rail formation that can be connected to the safety screen, the rail formation being oriented upwardly when operative, and the rail formation having engagement points that are spaced apart long the rail formation; the lifting bracket according to any one of claims 1 to 12; and an actuator that is connected to the lifting bracket and connected to the building, and the actuator is operable to drive the lifting bracket along the rail formation.
14. 14. The apparatus according to claim 13, wherein the apparatus includes a foot bracket that is arranged to releasably interconnect the actuator to the building.
15. 15. The apparatus according to claim 14, wherein the foot bracket is pivotally connected to the building via a first pivot connection, and the foot bracket is pivotally connected to the actuator via a second pivot connection.
16. 16. The apparatus according to claim 15, wherein the apparatus includes an anchoring member that can be fixed to the building by fasteners, and the first pivot connection is provided by a first removable pin that passes through openings of the foot bracket and the anchoring member when the openings are aligned, thereby allowing the foot bracket to be released from the anchoring member by removing the pin.
17. 17. The apparatus according to claim 16, wherein the second pivot connection includes a second removable pin that passes through openings in the foot bracket and the actuator, thereby allowing the actuator to be released from the foot bracket by removing the pin.
18. 18. The apparatus according to any one of claims 13 to 17, wherein the apparatus includes a lower latch that can engage the engagement points that are spaced apart long the rail formation, the lower latch being arranged to support the weight of the safety screen when the lifting bracket is disengaged from the engagement points.
19. 19. The apparatus according to any one of claims 13 to 17, wherein apparatus includes a lower latch that can engage the engagement points of the rail formation, the lower latch being pivotally connected to anchoring member, whereby when in use, the actuator is operable to raise the lifting bracket, which in turn causes the lifting portion to engage the engagements points and lift the safety screen, and as the engagement points of the rail formation move upwardly, downwardly facing surface of the lower latch are contacted by the upwardly moving engagement points, causing the lower latch to pivot upwardly to allow the engagement points to progress past the lower latch, and the actuator is operable to lower the lifting bracket to cause the next engagement point above the lower latch to engage the lower latch and thereby enable the weight of the safety screen to transferred from the lifting bracket to the lower latch, wherein the lower latch is arranged to be prevented from pivoting below an operative position at which the lower latch supports the weight of the safety screen, and thereafter the actuator is operable to further lower the lifting bracket, whereby the lifting bracket progresses down the rail formation and when the engagement points contact a downwardly facing of the lifting portion, the lifting portion can pivot upward to allow the lifting bracket to move downward and along the rail formation to a new lower position on the rail formation.
20. 20. The apparatus according to claim 19, wherein the lifting portion of the lifting bracket and the lower latch pivot downwardly from a raised position under gravity.
21. 21. An apparatus for elevating a safety screen arranged about the perimeter of a building during construction, the screen having a rail formation that extends upwardly and engagement points that are spaced apart upwardly on the rail formation, the apparatus includes: an actuator that can be releasably connected to the building; and a lifting bracket that includes: i) a coupling portion that can shift between a closed operative configuration in which the lifting bracket can move along and be retained on the rail formation, and an opened configuration in which the bracket can be removed from the rail formation, wherein the coupling portion includes two bodies that move relative to each other to allow the coupling portion to shift between the opened configuration and the closed configuration, and ii) a lifting portion that is releasably connected to the coupling portion, and when the bracket is in the closed operative configuration on the rail formation, the actuator is operable to move the lifting bracket upwardly along the rail formation so that the lifting portion can engage one of the engagement points to raise the screen to a new elevation, following which the actuator can be operated to lower the lifting bracket along the rail formation to align the lifting portion with another of the engagement points disposed below for further raising of the screen.