Beam former

Abstract

Former (1) for concrete beams comprising: an upper beam (2) having a first lateral outer end and a second lateral outer end; a first dropper beam (3) pivotably connected at an upper end to the first l

Description

Field of the Invention The invention relates to construction and the formation of concrete beams in situ. Background It is necessary to form concrete beams in many construction situations. This often done using formwork in which a mould of wooden or steel sheets or planks is formed and concrete is poured into the mould and allowed to set. This is an effective way of forming concrete beams in a lot of concrete situations. However, there are situations where space is tight and / or ground conditions are unfavourable and it is not possible to easily set up formwork. In such situations there is a need for an alternative apparatus for providing formwork and a method of using that apparatus for forming concrete beams. Summary of the Invention The present invention provides a former for concrete beams comprising: an upper beam having a first lateral outer end and a second lateral outer end; a first dropper beam pivotably connected at an upper end to the first lateral outer end of the upper beam; a second dropper beam pivotably connected at an upper end to the second lateral outer end of the upper beam; and an extendable spreader beam mounted at a first end to an inner side of the first dropper beam and mounted at a second end to an inner side of the second dropper beam; wherein the spreader beam can be extended from a first position in which the first dropper beam and the second dropper beam are vertical to a second position where the first dropper beam and the second dropper beam are pivoted away from vertical about their upper ends. The former of the present invention is advantageous in that it provides a simple and robust apparatus for forming concrete beams in situations where traditional formwork is unsuitable or cannot be used. The operation of the beam former will be understood with reference to the embodiment described below and with reference to the figures. Although it is generally preferred that both the first dropper beam and the second dropper beam are pivotably connected to the upper beam, in embodiments of the invention only one of the first or second dropper beam may be pivotably connected and the other of the first and second dropper beam may be rigidly connected to the upper beam. The spreader beam may be any beam that can be acted to spread apart the first dropper beam and the second dropper beam. Suitable apparatus include but are not limited to hydraulic pistons and extendible screw beams. The operation of the spreader beam may be manual or automatic. For example, an extendible screw beam may be extended manually by twisting of the spreader beam and a hydraulic piston may be operated automatically and remotely by a hydraulic control. In embodiments of the invention the spreader beam may rigidly fixed to the first dropper beam at the first end, is rigidly fixed to the second spreader beam at the second end and the spreader beam has a hinged connection formed part way between the first end and the second end. This construction allows the spreader beam to spread apart the first dropper beam and the second dropper beam without causing unnecessary strain on any connections or any of the beams of the former. Alternatively, the spreader beam may be rotationally fixed to the first dropper beam at the first end and / or rotationally fixed to the second dropper beam at the second end. The rotational connections may be formed in any manner apparent to the person skilled in the art. In order to control the position of the first and second dropper beams the former may comprise one or more adjusting bolts, or other position limiting means, positioned adjacent the upper end of the first dropper beam and / or the second dropper beam to limit inward rotation movement thereof. Adjusting bolts may be positioned in mounting plates formed on a lower side of the upper beam and may be adjustable to adjust the limit of the innermost position of the first drop beam and / or the second drop beam. For example, they may be screw bolt mounted through a threaded hole in a mounting plate. A former according to the present invention may comprise lifting shackles positioned on the upper beam for lifting the former. Lifting shackles may be used to lift the former into and out of position using a crane or other lifting means. A former according to the present invention may further comprise a first end connector plate mounted at an inner side of a lower end of the first dropper beam and a second end connector plate mounted at an inner side of a lower end of the second dropper beam. Connector plates can be provided to allow better connection to formwork, as described below. Connector plates may be formed in any manner apparent to the person skilled in the art and may be permanently fixed or removably attached to a dropper beam. Each dropper beam may be pivotably connected to the upper beam in any manner apparent to the person skilled in the art. In embodiments the dropper beams may be pivotably connected to the upper beam by means of hinge pin or by any other suitable pivotable fixing. The beams of the present invention may be formed in any manner apparent to the skilled person. The beams may be steel beams. The present invention also provides a system for forming concrete beams comprising a former, as described above and as defined in the claims, and formwork for removable attachment to the lower end of the first dropper beam and the lower end of the second dropper beam. The formwork may be formed of steel plates that are for direct or indirect attachment to the lower ends of the first and second dropper beams. The formwork may be sized and shaped to define the shape of a beam to be cast. The present invention also provides a method of forming a concrete beam using the system of the present invention. The method comprises the steps of: bolting the formwork in position at the lower end of the first dropper beam and the lower end of the second dropper beam; casting a concrete beam within the formwork; removing the formwork; extending the spreader beam to pivot the first dropper beam and the second dropper beam outwards; and lifting the former away from the beam. The method of the present invention allows concrete beams to be formed in a simple manner and is particularly useful in situations where traditional form work cant be easily positioned and constructed. Further features and advantages of the present invention will be apparent from the embodiment shown in the Figures and described below. Drawings Figure lisa side view of a former according to the present invention in an open position; Figure 2 is a side view of the former of Figure 1 in a closed position; Figure 3 is a side view of a system according to the present invention including the former of Figures 1 and 2. A former 1 according to the present invention is shown in Figures 1 and 2. The former comprises an upper beam 2, a first dropper beam 3, a second dropper beam 4, a spreader beam 5, a first connector plate 6, and a second connector plate 7. An upper end of the first dropper beam 3 is pivotably mounted to an outer end of the upper beam 2 by means of a first hinge pin 8. An upper end of the second dropper beam 4 is pivotably mounted to the upper beam 2 by means of a second hinge pin 9. The first connector plate 6 is permanently mounted to an inner side of a lower end of the first dropper beam 3. The second connector plate 7 is permanently mounted to an inner side of a lower end of the second dropper beam 4 and is facing the first connector plate 6. The spreader beam 5 is permanently mounted to an inner side of the first dropper beam 3 at a first end and is permanently mounted to an inner side of the second dropper beam 4 at a second end. The spreader beam 5 comprises a rigid beam 5a connected at an outer end to the second dropper beam 4 and an extendible hydraulic beam 5b connected at an outer end to the first dropper beam 3. An inner end of the rigid beam 5a is pivotably connected to the inner end of the hydraulic beam 5b. The hydraulic beam 5b can be controlled to extend and contract to lengthen or contract the spreader beam 5. In Figure 3, the representation of the spreader beam 5 has been simplified to improve clarity. The spreader beam 5 of Figure 3 is constructed as shown in Figures 1 and 2. A first limiting bolt 10 is mounted on a lower side of the upper beam 2 through a first mounting plate 11 and is positioned adjacent an inner side of the first dropper beam 3. A second limiting bolt 12 is mounted on a lower side of the upper beam 2 through a second mounting plate 13 and is positioned adjacent an inner side of the second dropper beam 4. The first and second limiting bolts 10, 12 define an innermost position of the first and second dropper beams 3, 4, as can be seen in Figure 2. The first and second limiting bolts 10, 12 can be adjusted through the first and second mounting plates 11, 13 respectively in order to adjust the closed position of the former 1. When in the closed position a removable first locking bolt 14 is utilized to lock the first dropper beam 3 in position and to the upper beam 2. Similarly, when in a closed position a removable second locking bolt 15 is utilized to lock the second dropper beam 4 in position and to the upper beam 2. A system 16 according to the present invention is shown in Figure 3. The system 16 comprises a former 1 according to the present invention and steel form work 17. The formwork 17 can be formed in any manner according to the present invention. The system 16 of the present invention is operated in the following manner. In an area remote from the construction site the former is positioned appropriately. The formwork 17 is then arranged appropriately with a reinforcing cage located therein and affixed to the first and second connector plates 6, 7. The first and second dropper beams 3, 4 are locked in position using the first and second locking bolts 14, 15. The former 1 is then lifted into position on a transport using shackles and moved to a construction site. At the construction site the former 1 is lifted off the transport and positioned on a preformed concrete blinding. The formwork 17 is then grouted into position on the concrete blinding and bolted on to any sections that have been previously formed. The formwork 17 is grouted on to the previously formed sections if applicable. The concrete is then cast. Importantly, there is no requirement for any external propping of the formwork 17 or any other additional support of the formwork. The former 1 acts to appropriately support the formwork 17 during casting of the concrete. When concrete is poured into the formwork 17 it is advisable that concrete chute baffles or other suitable methods are used to ensure the poured concrete is directed to avoid excessive impact on the formwork 17. As an alternative to grouting the framework 17 into position the framework may comprise self adhesive backed compressible rubber or foamed plastic grout seals at a lower edge of the formwork to contact with a blinding. The weight of the former 1 will then make the seal between the framework 17 and the blinding and retain the former in position as concrete is poured. After sufficient curing time the first and second locking bolts 14, 15 are removed and the formwork 16 is unfixed from the first and second connector plates 6, 7. The former 1 is then moved from the closed position (of Figure 2) to the open position (of Figure 1). This is done by controlling the spreader beam 5 to expand, moving the first dropper beam 3 and the second dropper beam 4 outwards. The former 1 can then be lifted out of position and then the formwork 16 can be removed using a mould release agent if necessary. As can be seen in Figure 3, at each end of the formwork 17 there are four stainless steel short tubes 18 bolted to the formwork 17, each carrying a short length of stainless steel angle. When in use, the former 1 is lowered over a reinforcing cage (not shown) in an open position, as shown in Figure 1, and is then closed, thus securing the reinforcing cage in the former 1 so it can be lifted complete onto transport and taken to the construction site. After concrete has been poured and cured, the four stainless steel bolts 18 each side of the formwork 17 are removed to allow the former 1 to be opened and lifted clear. Steel void former plates (not shown) can be inserted between the ends of each former 1 to ensure mechanical separation where required and to allow for thermal expansion and contraction boards joints and seals to be formed between each beam. There may also be a bolt on end to form start and stop ends on runs of beams. This is only an exemplary method of using the former 1 of the present invention. The former may be used in any other method apparent to the person skilled in the art. Unless otherwise indicated by the claims or by context any feature of the embodiment of the invention shown in the Figures or described above may be included in an embodiment of the invention independent from any other feature.

Claims

1. A former for concrete beams comprising:an upper beam having a first lateral outer end and a second lateral outer end;a first dropper beam pivotably connected at an upper end to the first lateral outer end of the upper beam;a second dropper beam pivotably connected at an upper end to the second lateral outer end of the upper beam; andan extendable spreader beam mounted at a first end to an inner side of the first dropper beam and mounted at a second end to an inner side of the second dropper beam; whereinthe spreader beam can be extended from a first position in which the first dropper beam and the second dropper beam are vertical to a second position where the first dropper beam and the second dropper beam are pivoted away from vertical about their upper ends.

2. A former according to claim 1, wherein the spreader beam comprises a hydraulic piston.

3. A former according to claim 1, wherein the spreader beam comprises an extendible screw beam.

4. A former according to any preceding claim, wherein the spreader beam is rigidly fixed to the first dropper beam at the first end, is rigidly fixed to the second spreader beam at the second end and the spreader beam has a hinged connection formed part way between the first end and the second end.

5. A former according to any of claims 1 to 3, wherein the spreader beam is rotationally fixed to the first dropper beam at the first end and / or is rotationally fixed to the second dropper beam at the second end.

6. A former according to any preceding claim further comprising one or more fixing bolts for fixing the first dropper beam and / or the second dropper beam in a substantially vertical position.

7. A former according to any preceding claim further comprising one or more adjusting bolts positioned adjacent the upper end of the first dropper beam and / or the second dropper beam to limit inward rotation movement thereof.

8. A former according to any preceding claim further comprising lifting shackles positioned on the upper beam for lifting the former.

9. A former according to any preceding claim further comprising a first end connector plate mounted at an inner side of a lower end of the first dropper beam and a second end connector plate mounted at an inner side of a lower end of the second dropper beam.

10. A former according to any preceding claim, wherein the first dropper beam is pivotably connected to the upper beam by means of a hinge pin.

11. A former according to any preceding claim wherein the second dropper beam is pivotably connected to the upper beam by means of a hinge pin.

12. A system for forming concrete beams comprisinga former according to any of claims 1 to 11; andformwork for removable attachment to the lower end of the first dropper beam and the lower end of the second dropper beam.

13. A method of forming a concrete beam using the system of claim 12 comprising the steps of:bolting the formwork in position at the lower end of the first dropper beam and the lower end of the second dropper beam;casting a concrete beam within the formwork;removing the formwork;extending the spreader beam to pivot the first dropper beam and the second dropper beam outwards; andlifting the former away from the beam.10

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