The present invention relates to apparatus and a method for use in the manufacture 5 of a twin leaf reinforced concrete panel element of the type having spaced apart first and second leaves of reinforced concrete tied together with reinforcing members. The invention also relates to such a reinforced concrete panel element manufactured according to the apparatus and/or the method.

10. Such reinforced concrete panel elements are known. Typically, such. reinforced concrete panel elements are used in the construction of buildings, and in particular, are used in the construction of walls of a building, and in general, are used to form the inner load bearing leaf of an exterior wall of the building, although they may also be used to form internal load bearing walls of the building. In general, the panel 15 elements are placed standing on a concrete floor of the building with reinforcing elements extending upwardly from the floor between the first and second leaves of the panel elements. A pre-cast floor is then supported on one of the leaves of the panel elements, which typically, is the inner of the two leaves. Reinforcing elements extending downwardly from the pre-cast floor are located between the two leaves of 20 the panel elements. Concrete is then poured over the pre-cast floor and between the leaves of the panel elements so that the panel elements and the floor which is supported by the panel elements form effectively one integral reinforced concrete unit. The reinforcing elements extending upwardly from the floor on which the panel elements are standing are embedded in the concrete poured between the leaves of 25 the panel elements to similarly tie in the panel elements with the floor on which the panel elements are supported to similarly form an integral reinforced unit with the floor on which the panel elements are supported. Such panel elements and their use in the construction of a building will be known to those skilled in the art.

30 In the manufacture of these panel elements, the respective leaves are formed of reinforced concrete, and must be cast separately. Additionally, the external surfaces of the two leaves, in general, are required to be smooth, and thus must be cast on a suitable flat bed structure. This, thus, requires a first one of the leaves to be cast on a flat casting bed within screeds with reinforcing material for reinforcing the first leaf located within the screeds, and the reinforcing members which are to tie the two leaves together extending upwardly from the screeds. Concrete is poured into the screeds to an appropriate level corresponding to the desired thickness of the first leaf, and with the reinforcing members extending upwardly from the concrete, the concrete is cured. A second one of the leaves must then be cast with the reinforcing members extending from the first leaf and co-operating with the reinforcing material of the second leaf, so that the reinforcing members extending from the first leaf tie the second leaf to the first leaf.

Typically, such panel elements are mass produced on longitudinally extending casting beds. The first leaf is cast with the reinforcing members which are to engage the second leaf extending upwardly from the first leaf. Once the first leaf has been cured, it then has to be oriented through 180° and positioned over the casting bed where the second leaf is to be cast with the reinforcing members extending downwardly and co-operating with the reinforcing material of the second leaf, so that when the concrete of the second leaf is poured, the reinforcing members extending downwardly from the first leaf are cast into the second leaf.

A major problem encountered in the manufacture of such panel elements arises in the transfer and orientation of the first leaf into position for casting with the second leaf. Various apparatus have been provided for transferring and orienting a first leaf of such a panel element, however, in general, such apparatus suffer from various disadvantages. In some cases the apparatus is slow and results in inefficiencies in the manufacture of such panel elements, in other cases, the apparatus is relatively complex, and in other cases the apparatus is relatively expensive.

Accordingly, there is a need for an improved apparatus and a method for use in the manufacture of such twin leaf reinforced concrete panel elements.

The present invention is directed towards providing such an apparatus and a method, and the invention is also directed towards providing a twin leaf reinforced concrete panel element when manufactured by the method and/or apparatus.

According to the invention there is provided apparatus for use in the manufacture of a twin leaf reinforced concrete panel element having spaced apart first and second leaves of reinforced concrete tied together with reinforcing members, wherein the apparatus comprises at least one casting bed on which the first leaf is cast with the reinforcing members for engaging the second leaf extending upwardly therefrom, a support structure extending over the casting bed, a first gantry supported on the support structure above the casting bed, a lifting means carried on the first gantry for lifting the first leaf from the casting bed, a second gantry supported on the support structure above the casting bed, an orienting means carried on the second gantry for orienting the first leaf through 180° and for placing the first leaf on the casting bed or another one of the casting beds beneath the support structure, on which the second leaf is to be cast, with the reinforcing members extending downwardly from the first leaf, and for facilitating casting of the reinforcing members into the second leaf with the first and second leaves spaced apart, the orienting means being locatable for receiving the first leaf from the lifting means at a level below the lifting means, and one of the first and second gantries being moveable relative to the other between a first position with the orienting means aligned with the lifting means for receiving the first leaf from the lifting means, and a second position with the orienting means clear of the lifting means for facilitating lifting of the first leaf from the bed by the lifting means.

In one embodiment of the invention a securing means is provided on the orienting means for securing the first leaf thereto during orientation of the first leaf through 180°. Preferably, the securing means comprises at least one suction element for engaging and retaining the first leaf on the orienting means. Advantageously, a plurality of suction elements are provided. Ideally, a control means is provided for selectively applying a vacuum to each suction element.

In another embodiment of the invention the orienting means comprises a carrier. Preferably, the carrier is pivotal through 180° for orienting the first leaf through 180°. Advantageously, the carrier is pivotal about a horizontal pivot axis for orienting the first leaf through 180°.

Ideally, the pivot axis about which the carrier is pivotal extends parallel to the casting bed.

In a further embodiment of the invention the orienting means is moveable vertically for lowering the first leaf onto the casting bed or another one of the casting beds for casting with the second leaf. Preferably, the orienting means is moveable vertically relative to the second gantry.

In another embodiment of the invention the second gantry is moveable on the support structure between the first and second positions. Preferably, the second gantry is moveable on the support structure transversely of the casting bed between the first and second positions. Advantageously, the second gantry is moveable transversely of the casting bed for aligning the first leaf with another one of the casting beds.

In one embodiment of the invention the first lifting means comprises a hoist. Preferably, the hoist comprises a plurality of hooks for engaging the reinforcing members extending from the first leaf for facilitating lifting thereof.

In another embodiment of the invention the first gantry is moveable relative to the support structure between the first and the second positions. Preferably, the first gantry is moveable transversely of the casting bed between the first and second positions. Advantageously, the first gantry is moveable transversely of the casting bed for facilitating selectively aligning the first gantry with each casting bed.

Ideally, the second gantry is located on the support structure with the orienting means below the first gantry. Preferably, the second gantry is located on the support structure below the first gantry, and is moveable beneath the first gantry. In one embodiment of the invention a first drive means is provided for moving the first gantry relative to the support structure.

In another embodiment of the invention a second drive means is provided for operating the lifting means for lifting the first leaf from the casting bed.

In a further embodiment of the invention a third drive means is provided for moving the second gantry relative to the support structure.

In a still further embodiment of the invention a fourth drive means is provided for operating the orienting means for orienting the first leaf through 180°.

In another embodiment of the invention a fifth drive means is provided for urging the orienting means vertically relative to the second gantry.

In one embodiment of the invention each casting bed is an elongated bed, and the support structure is moveable longitudinally along the casting bed parallel thereto.

In another embodiment of the invention at least two longitudinally extending casting beds are provided, the casting beds extending parallel to each other.

The invention also provides a method for manufacturing a leaf of a twin leaf reinforced concrete panel element having spaced apart first and second leaves of reinforced concrete tied together with reinforcing members, the method comprising the steps of casting the first leaf on a casting bed with the reinforcing members extending upwardly therefrom, lifting the first leaf from the casting bed when the first leaf has cured and placing the leaf on an orienting means, operating the orienting means for orienting the leaf through 180° so that the reinforcing members extending from the first leaf extend downwardly therefrom, lowering the first leaf downwardly to the casting bed or another one of the casting beds on which the second leaf is to be cast, and casting the second leaf with the reinforcing members extending downwardly from the first leaf cast into the second leaf and the first and second leaves spaced apart.

In one embodiment of the invention the twin leaf reinforced concrete panel element is manufactured using the apparatus according to the invention.

The invention further provides a twin leaf reinforced concrete panel element having spaced apart first and second leaves of reinforced concrete tied together with reinforcing members, the panel element being manufactured according to the method according to the invention.

The invention also provides a twin leaf reinforced concrete panel element having spaced apart first and second leaves of reinforced concrete tied together with reinforcing members, the panel element being manufactured using the apparatus according to the invention.

The advantages of the invention are many. The apparatus is particularly suitable for use in the manufacture of twin leaf reinforced concrete panel elements of the type having spaced apart first and second leaves of reinforced concrete tied together with reinforcing members. A particular advantage of the invention is that the apparatus is a relatively simple and non-complex apparatus. By providing the lifting means for lifting the first leaves on one gantry, and the orienting means for orienting the first leaves through 180° on a separate gantry, the lifting means and the orienting means can be operated independently of each other, and thus, the operations of lifting the first leaves and orienting the first leaves can be carried out independently of each other. Furthermore, by providing the lifting means and the orienting means on separate gantries, the lifting and orienting means can be provided as being relatively simple and non-complex devices.

The invention will be more clearly understood from the following description of a preferred embodiment thereof, which is given by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a panel element according to the invention,

Fig. 2 is an end elevational view of the panel element of Fig. 1 ,

Fig. 3 is a perspective view of apparatus according to the invention for use in the manufacture of the panel element of Fig. 1 ,

Fig. 4 is an end elevational view of the apparatus of Fig. 3,

Fig. 5 is an end elevational view of a portion of the apparatus of Fig. 3,

Fig. 6 is an end elevational view similar to Fig. 5 illustrating the portion of the apparatus of Fig. 3 with a portion of the apparatus in a different position, and

Fig. 7 is an end elevational view similar to Fig. 5 illustrating the portion of the apparatus of Fig. 3 with a portion of the apparatus in a further different position.

Referring to the drawings and initially to Figs. 1 and 2, there is illustrated a panel element according to the invention, indicated generally by the reference numeral 1, for use in the construction of a building. The panel element 1 is of the type which would normally form an inner leaf of an outer wall of the building between two floors. Briefly, the panel element 1 comprises a first leaf 2 and a second leaf 3 which are spaced apart from each other and tied together by reinforcing members 5. Each first and second leaf 2 and 3 is of reinforced concrete, and the reinforcing members 5 extending between the first and second leaves 2 and 3 form part of the reinforcing of the respective first and second leaves 2 and 3. Typically, in use, the panel element 1 would be placed on a floor with the second leaf 3 facing into the building.

Referring now to Figs. 3 to 7, there is illustrated apparatus according to the invention, indicated generally by the reference numeral 10, for use in the manufacture of the panel element 1. The apparatus 10 comprises three longitudinally extending parallel casting beds 11 of steel plate on which the first and second leaves 2 and 3 are cast. The casting beds 11 are supported on a plurality of spaced apart ground engaging supports 12, see Figs. 4 to 7. The casting beds 11 each define an upper smooth surface 14 so that outer surfaces 15 of the respective first and second leaves 2 and 3 are cast with a smooth surface. Such casting beds 11 will be well known to those skilled in the art, and it is not intended to describe the casting beds in further detail. However, it will be appreciated that in order to cast the first and second leaves 2 and 3 on the casting beds 11, appropriate casting screeds are secured to the casting beds 11. Casting screeds 16 for the second leaves 3 only are illustrated diagrammatically in Figs. 5 to 7. The casting screeds may be secured by any suitable means, and typically are secured by magnetic clamping means. Such casting screeds will be well known to those skilled in the art.

A support structure, indicated generally by the reference numeral 20, extends over the three casting beds 11, and is moveable longitudinally along the beds 11 on a pair of tracks 21 , which extend parallel to the casting beds 11 on respective opposite sides of the casting beds 11. Track engaging wheels (not shown) are rotatably carried on the support structure 20 for engaging the tracks 21 , and for facilitating rolling the support structure 20 longitudinally along the casting beds 11. The track engaging wheels (not shown) are rotatably carried between respective pairs of longitudinally extending side members 24 of the support structure 20. Four uprights 25 extending from the side members 24 support an overhead frame 26 comprising a pair of spaced apart transverse members 27 which are joined by respective longitudinally extending cross members 28. Transversely extending struts 29 reinforce and stabilise the support structure 20. The support structure 20 is formed of I-section rolled steel joists.

A first gantry 30 is carried on the overhead frame 26 of the support structure 20, and is moveable transversely relative to the casting beds 11 along the transverse members 27 between respective ends 32 and 33 of the frame 26. Rollers (not shown) on the first gantry 30 rollably engage the transverse members 27, which act as tracks for guiding the first gantry 30 between the ends 32 and 33 along the overhead frame 26. A first drive means, namely, a first electrically powered drive motor 35 on the first gantry 30 drives the rollers (not shown) for urging the first gantry 30 along the transverse members 27.

A lifting means, in this embodiment of the invention a hoist 38 is carried on the first gantry 30 for lifting the first leaves 2 from the casting beds 11. The hoist 38 comprises a pair of drums 39 onto which hoist cables 40 are wound for raising and lowering a lifting frame 42. A plurality of hooks 43 extend downwardly from the lifting frame 42 for engaging and hooking onto the reinforcing members 5 extending from the first leaves 2 for lifting the cured first leaves 2 from the casting beds 11. The first leaves 2 are lifted one at a time by the hoist 38. A second drive means, namely, a second electrically powered drive motor 44 is carried on the first gantry 30 for rotating the drums 39 for raising and lowering the cables 40 and in turn, the lifting frame 42.

A second gantry 45 is carried on the overhead frame 26, and is also moveable transversely relative to the casting beds 11 along the transverse members 27 between the end 32 and the end 33 of the frame 26, at a level below the level of the first gantry 30. Rollers 47 rollably engage the transverse members 27 at a level lower than the first gantry 30. The rollers (not shown) of the first gantry 30 rollably engage an upper web 48 of the rolled steel joists forming the transverse members 27, while the rollers 47 of the second gantry 45 engage a lower web 49 of the rolled steel joists forming the transverse members 27. A third drive means, namely, a third electrically powered drive motor 51 carried on the second gantry 45 drives the rollers 47 for urging the second gantry 45 along the transverse members 27.

An orienting means comprising a carrier element 50 is carried on the second gantry 45 for receiving the first leaves 2 from the hoist 38, and for orienting the first leaves 2 through 180° from a first position illustrated in Fig. 5 with the reinforcing members 5 of the first leaves 2 extending upwardly therefrom, to a second position illustrated in Fig. 6 with the reinforcing members 5 extending downwardly from the first leaves 2. The carrier element 50 is carried on the second gantry 45 by four telescoping rams 53 extending downwardly from the second gantry 45, and comprises a pair of end members 54, which are secured to the rams 53 for raising and lowering of the carrier element 50. A carrier plate 56 for receiving and orienting the first leaves 2 is pivotally carried between the end members 54 by pivot shafts 57. The pivot shafts 57 extend rigidly from respective opposite ends of the carrier plate 56, and engage bearings (not shown) in end members 54, and define a horizontal pivot axis about which the carrier plate 56 is pivotal through 180° for orienting the first leaves 2 through 180° between the first and second positions. The pivot axis defined by the pivot shafts 52 extends parallel to the casting beds 11. A fourth drive means, namely, a fourth electrically powered drive motor 58 mounted on one of the end members 54 of the carrier element 50 rotates the corresponding pivot shaft 52 through 180°, for in turn, rotating the carrier plate 56 through a corresponding angle of 180°. The first leaves 2 are oriented through 180° one at a time by the carrier element 50. The telescoping rams 53 act as a fifth drive means for vertically urging the orienting element 50 upwardly and downwardly relative to the second gantry 45 for lowering the oriented first leaves 2 with their reinforcing members 5 extending downwardly from the first leaves 2 onto the casting beds 11 for casting with the second leaves 3.

A securing means, namely, a plurality of suction elements 59 are carried on the carrier plate 56 for engaging the smooth outer surface 15 of the first leaves 2 and for retaining the first leaves 2 secured to the carrier plate 56. A control means, namely, a controller (not shown) selectively applies a vacuum, which is generated by an external vacuum system (not shown), to the suction elements 59 for securing and retaining the first leaves 2 on the carrier plate 56. Such suction elements will be well known to those skilled in the art.

The telescoping rams 53 have sufficient travel for lowering the carrier element 50 to a position just above the casting beds 11 , for in turn, lowering a first leaf 2 with the reinforcing members 5 extending downwardly therefrom into position just above the casting bed 11 , so that the reinforcing members 5 of the first leaf 2 secured to the carrier element 50 extend downwardly from the first leaf 2, and are located within the casting screeds (not shown) for the corresponding second leaf 3 for facilitating casting of the second leaf 3 with the reinforcing members 5 cast into the second leaf 3.

In use, a plurality of first leaves 2 are cast on any one or all of the casting beds 11 , however, an appropriate number of spaces are left on the respective casting beds 11 for casting a corresponding number of second leaves 3. Initially, the casting screeds for forming the first leaves 2 are secured to the casting beds 11 at the appropriate locations, the appropriate reinforcing steel material is placed on the casting beds 11 spaced apart therefrom within the casting screeds, and the reinforcing members 5 which are to extend upwardly from the first leaves 2 for subsequent casting into the second leaves 3 are also provided within the casting screeds. Concrete is then poured into the casting screeds to a level corresponding to the desired thickness of the first leaves 2, so that the reinforcing members 5 extend upwardly therefrom. On curing of the first leaves 2, the first gantry 30 is positioned over one of the first leaves 2, and the second gantry 45 is moved into a second position clear of the first gantry 30, for example, the position illustrated in Fig. 4. The hoist 38 is operated for lowering the lifting frame 42 downwardly for engaging the lifting hooks 43 with the reinforcing members 5 of the first leaf 2. The engaged first leaf 2 is then raised by the hoist 38 to a level above the level of the carrier element 50 of the second gantry 45, and the second gantry 45 is urged along the transverse members 27 into a first position with the carrier element 50 beneath and aligned with the lifting frame 42, se Figs. 5 and 6. The lifting frame 42 is then lowered for lowering the first leaf 2 onto the carrier plate 56 of the carrier element 5O1 and the vacuum is applied to the suction elements 59 for securing the first leaf 2 to the carrier plate 56.

The hooks 43 are disengaged from the reinforcing members 5 of the first leaf 2, and the lifting frame 42 is lifted clear of the carrier plate 56. The carrier element 50 is positioned at a level between the casting beds 11 and the overhead frame 26, so that the carrier plate 56 with the first leaf 2 secured thereto can be pivoted through 180°. The fourth drive motor 58 is operated for pivoting the carrier plate 56 through 180°, so that the first leaf 2 is oriented through 180° from the first position to the second position, and in the second position, the first leaf 2 is located beneath the carrier plate 56 with the reinforcing members 5 extending downwardly therefrom. The second gantry 45 is then urged along the transverse members 27 until the second gantry, and in turn the carrier plate 56 with the first leaf 2 secured thereto is located over the casting bed 11 and the area of that bed 11 on which the second leaf 3 of the panel element 1 is to be cast. If necessary, the support structure 20 is urged longitudinally along the casting beds 11 in order to locate and align the carrier plate 56, and in turn the first leaf 2 over the appropriate portion of the casting bed 11. With the first leaf 2 aligned with the screeds of the corresponding second leaf 3, the rams 53 are operated for lowering the carrier element 50, and in turn the first leaf 2 to a position just above the corresponding casting bed 11. The carrier element 50 is lowered until abutment members 64 extending from the reinforcing members 5 of the first leaf 2 are located within the screeds 16 on the casting bed 11 of the corresponding second leaf 3, and engage the bed 11 within the casting screeds 16 for the second leaf 3 for supporting the reinforcing members 5 above the casting bed 11. The abutment members 64 extend from the reinforcing members 5 a distance which is such that when the abutment members 64 are in engagement with the bed 11 , the reinforcing members 5 engage the reinforcing steel material of the second leaf 3, for tying in the reinforcing members 5 with the reinforcing steel material of the second leaf 3. The abutment members 64 terminate in caps of plastics material to avoid the steel of the abutment members 64 being exposed through the concrete of the second leaf 3. Thereafter the vacuum is removed from the suction elements 59, thus disengaging the first leaf 2 from the carrier plate 56, and the rams 53 are again operated for raising the carrier element 50 clear of the first leaf 2.

Concrete is then poured into the screed 16 to a level corresponding to the desired thickness of the second leaf 3 to form the second leaf 3 with the reinforcing members 5 cast therein, and with the first and second leaves 2 and 3 spaced apart from each other and tied by the reinforcing members 5.

When the second leaf 3 of the panel element 1 has cured, the second gantry 45 is positioned over the panel element 1 , and the carrier element 50 is lowered to the panel element 1. The outer surface 15 of the first leaf 2 is engaged by the suction elements 59 for lifting the panel element 1 from the casting bed 11. The second gantry 45 is then urged along the transverse members 27 towards the end 33 of the frame 26, and the panel element 1 is then lowered by the rams 53 onto a suitable pallet, truck flat or the like for transportation. As can be seen, the end 33 of the frame 26 extends beyond the tracks 21 for facilitating lowering of the cast panel elements 1 clear of the casting beds 11.

While the apparatus has been described as comprising three longitudinally extending parallel casting beds, it will be appreciated that the apparatus may be provided with any number of casting beds, and indeed, in certain cases, it is envisaged that the apparatus may be provided with one single casting bed only.

It will be appreciated that the first gantry may be provided with any other suitable lifting means for lifting the first leaves from the casting beds above the orienting means.. It will also be appreciated that any other suitable orienting means besides a carrier plate may be provided for orienting the first leaves between the first and second positions.

While the fifth drive means for raising and lowering the orienting means on the second gantry have been described as being provided by telescoping rams, any other suitable means for raising and lowering the orienting means may be provided.

It is envisaged that other suitable drive means besides electrically powered drive motors may be used for urging the first and second gantries along the overhead frame, and for hoisting the first leaves from the casting beds and for operating the carrier plate for orienting the first leaves. Indeed, in certain cases, it is envisaged that the drive motors may be provided by pneumatic motors, hydraulic motors or the like. It is also envisaged that two first drive motors and two third drive motors may be provided for urging the first and second gantries along the transverse members of the overhead frame. In which case, it is envisaged that one of the first drive motors would be provided on one side of the gantry, and the other first drive motor would be provided on the other side of the first gantry for driving the rollers on the respective opposite sides of the gantries. In which case, the two first drive motors would be synchronised. Similarly, where two second drive motors are provided, the respective second drive motors would be provided on respective opposite sides of the second gantry for driving the corresponding rollers on the respective opposite sides of the second gantry. Again, the two second drive motors would be synchronised.

Needless to say, it will be appreciated that the four telescoping members will also be synchronised in order to raise and lower the orienting element evenly.

While the support structure has been described as being of a particular construction, any other suitable construction may be used.

It is also envisaged in certain cases that the second leaves may be cast initially with the reinforcing members extending upwardly therefrom, and in which case, the second leaves would then be raised by the hoist and oriented by the orienting element through 180°, and then lowered onto one of the casting beds for casting with a corresponding first leaf.