AU2004285987B2 - A lifting assembly for a shutter to allow continuous casting - Google Patents

Description

WO 2005/042876 PCT/AU2004/001497 A LIFTING ASSEMBLY FOR A SHUTTER TO ALLOW CONTINUOUS CASTING This invention relates to both an arrangement and a means for lifting formwork or 5 shutters during construction of a building. Modern construction of buildings normally comprises stage by stage pouring of concrete to form columns and floors. Such construction techniques will be known to a skilled addressee of this specification. 10 In addition to constructing columns and floors, it is often a requirement to construct internal or peripheral walls that extend vertically through all or of part of the building structure. Such walls are constructed using ordinary formwork or shuttering techniques. However, the construction of shuttering for such walls cannot, 15 commence until access is provided to a new floor and this does not occur until the floor is poured and finished. The shuttering then needs to be assembled and positioned on each floor using a crane and then disassembled to move to the next level. This is obviously a time consuming process. 20 It is an object of this invention to provide an alternate means for positioning structure forming shuttering which is more efficient and less time consuming than the current construction techniques. In one aspect, the invention is a lifting assembly comprising 25 a support frame, a shutter slidably engaged to said support frame, and a hoist operatively connected between said support frame and shutter to cause movement of said shutter with respect to said support frame where, in use, when said support frame is fixed, operation of said hoist causes movement of said shutter WO 2005/042876 PCT/AU2004/001497 2 and when said shutter is fixed, operation of said hoist causes movement of said support frame. Preferably, the hoist comprises a hoist means and a hoist actuator operatively 5 engaged to the hoist means. Preferably, the lifting assembly is used in a multi storey building and the support frame can extend over a number of levels including floors yet to be constructed in the building. The shutter is preferably used to manufacture vertically extending walls, 10 and can be used to cast a portion of the wall whereupon it can then be lifted to cast the next portion of the wall directly on that portion cast below. In this way, the wall can be continuously formed in a vertical direction by progressive movement of the shutter. 15 This invention enables a structure such as a wall to be formed prior to other components, such as floors, being cast in place. Apertures are formed in the floor either side of the structure being formed to allow the support frame to extend between floors. These apertures can later be infilled once the support frame is lifted clear of the floor. 20 Supports may be used to hold both the support frame or the shutter in relation to a support surface such as a lower floor. In this way, when the support frame is held, the shutter can be lifted by the hoist means in relation to the support frame. Alternately, when the shutter is supported, the support frame can be lifted by the 25 hoist means with respect to the shutter. In this way, the shutter can be continuously lifted upwardly as the building is being constructed. In order to fully understand the invention, a preferred embodiment is described below. However, the invention is not limited to the precise combination of the WO 2005/042876 PCT/AU2004/001497 3 elements described in this embodiment and other aspects of the invention will be apparent from the description. This embodiment is illustrated in the following drawings in which: 5 Figure 1 shows a plan view of the lifting arrangement, Figure 2 shows a side view of the lifting arrangement, Figures 3 to 5 show a lifting sequence of the arrangement, and Figure 6 shows detail of an attachment bracket. 10 Figure 1 shows a plan view of the lifting arrangement. It includes a support frame or a main frame that comprises columns 10. Each column 10 is a pair of C-shaped channels that are held back to back. Four columns 10 are provided and a shutter 11 is positioned between them. In this embodiment, the shutter 11 is used to form a vertical wall where the width and thickness of the wall is defined by the shutter 11. 15 The shutter 11 has means whereby the shuttering can be stripped from the wall that is formed once the concrete is set. This stripping process ensures that all concrete forming surfaces are released or pulled away to enable the shutter 11 to slide vertically over the wall that is formed. 20 The shutter 11 is attached to the columns 10 by brackets 12 that are illustrated in Figure 6. The brackets 12 are approximately 2 meters in lengths and have flanges 13 that locate over the walls of the two C-shaped beams that form the columns 10. This retains the bracket 12 with respect to the column 10 and enables it to slide vertically along the columns 10. 25 Figure 1 also shows a motor beam 15 that is secured to the shutter 11 between adjacent columns 10. The motor beam 15 carries an electric motor 16 that drives a pair of screw jacks 17 which are both mounted on the motor beam 15. The operation of the screw jacks will be described below. 30 WO 2005/042876 PCT/AU2004/001497 4 The electric motor 16 drives the screw jacks via a reduction gearbox attached to electric motor 16 and output drive shafts 18. Figure 2 shows a side view of the arrangement shown in Figure 1. The columns 10 5 extend over several floors of the building some of which are yet to be constructed. In Figure 2, level A shows a constructed floor whereas levels B, C and D are yet to be constructed. The shutter 11 is forming a vertical wall that is to extend vertically through the floors of the building. 10 Each motor beam is operatively engaged to a hoist means which in this embodiment comprises worm screw shafts 20. A pair of shafts 20 are provided with each motor beam 15 and are threadably engaged through the screw jacks 17 which comprise the hoist actuator. 15 A number of different hoist means and hoist actuators may be used. For example, the hoist means may comprise an elongate tooth rack with a hoist actuator comprising a driven gear. However, in this embodiment, the hoist means comprises an elongate screw shaft 20 and the hoist actuators are screw jacks 17. 20 The screw shafts 20 are connected at their upper ends to the columns 10. The lower end of the screw shaft 20 is also connected to the columns 10. In this way, the shutter 11 is supported by the motor beam 15 with the screw shaft 20 above the motor beam 15 being placed in tension. 25 With the columns 10 fixed, operation of the electric motor 16 in one direction drives the motor beam 15 and the shutter 11 upwardly along the screw shafts 20. This lifts the shutter 11 with respect to the columns 10. Figures 3 to 5 show, in sequence, the operation of the lifting arrangement. In Figure 30 3, level A represents a floor which has already been poured. The lower ends of the WO 2005/042876 PCT/AU2004/001497 5 columns 10 are below the floor at level A and supported at the floor below. The shutter 11 is being used to form a wall 22. The wall 22 already extends above level C and the last section of the wall has just been cast in the shutter 11. 5 The shutter 11 is also supported by props 23 that are attached to the lower edge of the shutter 11 and are secured to the floor at level A. At least 4 props 23 are used. The lifting assembly is also stabilised by the formwork 11 which surrounds at its lower edge the wall 22 and so abuts against that portion of the wall 22 within the formwork 11 prior to casting and the whole wall 22 after casting. 10 Figure 4 shows the columns 10 after they have been lifted to the next casting position. From this position the shutter 11 can then form the rest of the wall 22 between level C and D and a portion of the wall 22 above level D. 15 In Figure 4, the floor at level B has been poured and apertures around each of the columns 10 adjacent wall 22 are formed in the floor when level B is poured. After the columns 10 are lifted out of the way, these apertures can be closed by infill. However, the apertures in the floor of level B enable the columns 10 to extend below level B into the space above level A. The props 26 are re-positioned on level B once 20 the floor is set. The apertures adjacent wall 22 on level A are infilled and props 27 are used to support the columns 10 in relation to level A. Another portion of the wall 22 is then cast in the shutter 11. In the position shown in Figure 5 it is not possible to lift the shutter 11 without first 25 lifting the columns 10. In order to achieve this, props 23 are attached to shutter 11 at points 24. With the shutter 11 held in place by the props 23, the electric motors 16 can be operated in reverse so that the columns 10 are lifted. Skids 25 abut against the wall 22 and stabilise the columns 10 as they are lifted. The columns 10 are lifted through the apertures in the floor at level B and once they are above level B floor, WO 2005/042876 PCT/AU2004/001497 6 then the props 26 and 27 are again attached to the columns 10 to allow the shutter 11 to be raised to its new position. In this manner, the columns 10 and shutter 11 can work their way up the height of a 5 building to form the wall 22. As seen in Figures 2 to 5, working platforms can be positioned on the top of the shutter 11. This provides convenient access for workmen pouring concrete into the shutter 11. 10 The invention provides a means and method whereby a wall 22 can be formed well in advance of floors that can then be formed below. This means that the construction of the wall 22 is continuing above the formwork that is being used to cast the floors of the building. Accordingly, there is no delay as is the case with existing 15 construction techniques where a floor needs to be finished before formwork can be placed to construct the vertical wall. The invention also allows large wall forming shutters to be lifted without the need to use a crane.

Claims (9)

1. A lifting assembly comprising: a pair of support frames a shutter for the continuous forming of a wall slidably engaged to and between said support 5 frames, said shutter defining a wall section of predetermined width and thickness, a hoist means extending vertically and secured at each end with respect to at least one of said support frames, and a hoist actuator mounted on said shutter, said hoist actuator engaging said hoist means to cause movement of said shutter with respect to said support frames where, in use, when said support 0 frames are fixed, operation of said hoist actuator causes movement of said shutter and when said shutter is fixed, operation of said hoist actuator causes movement of said support frames.

2. A lifting assembly according to claim I wherein said support frame comprises a plurality of columns. 5

3. A lifting assembly according to claim 2 wherein there are four columns, two of said columns located on either side of said shutter and positioned adjacent the outer edges of said shutter.

4. A lifting assembly according to claim 3 wherein said hoist means comprises a screw shaft secured .0 at each end to each of said columns.

5. A lifting assembly according to claim 4 wherein said hoist actuator comprises a screw jack that engages and rotates on each of said screw shafts. 25

6. A lifting assembly according to claim 5 further comprising a beam secured to either side of said shutter, said screw jacks located at each end of each said beam.

7. A lifting assembly according to any one of claims 1 to 6 wherein said shutter is fixed with respect to a floor of a building by a plurality of struts to allow said support frames to move upwardly 30 with respect to said shutter.

8. A lifting assembly according to any one of claims I to 6 wherein said support frames are fixed with respect to a floor of a building by a plurality of struts to allow said shutter to move upwardly with respect to said support frames. 35 8

9. A lifting assembly comprising: a pair of support frames, a shutter for the continuous forming of a wall slidably engaged to and between said support frames, said shutter defining a wall section of predetermined width and thickness, and 5 a hoist connected between said support frames and shutter to cause movement of said shutter with respect to said support frames where, in use, when said support frames are fixed, operation of said hoist causes movement of said shutter and when said shutter is fixed, operation of said hoist causes movement of said support frames.