1 RECESS FORMER FOR CONCRETE PANELS Field of the Invention The present invention relates to a recess former assembly and to a method of forming 5 a recess around a lifting anchor or other embedded item cast into a concrete element. Background Art During the manufacture of concrete elements, such as panels, beams, columns and other products it is often necessary to cast components of metal or other materials into 10 the concrete element. These components are generally used to attach other elements to the concrete element or are used for the attachment of a lifting shackle for the lifting and handling of the concrete element itself Such components include so called lifting anchors which are used to attach lifting 15 equipment to a concrete panel or like element and are most commonly manufactured from steel, iron or other ferromagnetic materials. Such lifting anchors in widespread use are of a substantially elongate cylindrical or planar forms comprising a free end shaped to connect to a connection device and another distal end which is shaped to form a mechanical interlock with the concrete in which it is embedded. 20 The lifting anchors are embedded in the concrete elements at the time of casting the concrete. When setting up the mould or formwork, the free end of the anchor which is shaped to attach to the lifting shackle is secured in a recess former. Most commonly the recess former is attached to the form-work or mould used to cast the 25 concrete element. After the concrete has hardened and the mould or form-work is removed, the recess former is itself removed, leaving a recess in the surface of the concrete element such that the attachment end of the anchor is accessible. Genesis of the Invention 30 The genesis of the present invention is a desire to provide an improved recess former for forming a recess in a concrete element in which the free end of a lifting anchor or other item embedded in the concrete element is located, thereby allowing the free end of the lifting anchor or other item to be accessible after the concrete has been cast. 51750-AU & NZ Summan' of the Invention In accordance with a first aspect of the present invention there is disclosed a recess former for a cast concrete element having an anchor with a head shaped for connection to an attachment device, said element being cast in formwork, said former 5 having an opening which is shaped to receive the head of the anchor and a body which defines the shape of the recess, and said former being divided into two parts along a line which passes into said opening to permit said head to enter said opening, wherein said former is adapted to lie alongside said fornnwork without being attached to said formwork, and 10 wherein said former includes at least one magnetic element located within the former to maintain said former parts engaged with said head by niagnetic attraction between the magnetic element(s) and the anchor. 15 20 25 30 5 750-AU 3 In addition to the forgoing there is also disclosed a concrete element such as a building panel incorporating at least one recess formed by the above mentioned recess fomner 5 A method of casting and/or lifting a concrete element incorporating at least one recess formed with the abovementioned recess former as described above is also disclosed. Brief Desripio of the Drawijjg Preferred embodiments of the present invention wil now be described with reference 10 to the drawings in which: Fig, I is an exploded perspective view of a prior art recess former and planar lifting anchor., Fig, 2 is a side elevation of the prior art recess former of Fig. 1, Fig. 3 is a side elevation of the prior art recess former of Fig, I with a planar 15 lifting anchor inserted therein., Fig, 4 is a cutaway perspective view of the prior art recess former and planar lifting anchor of Fig; I shown in concrete after it has been cast and before the removal of the recess former, Fig. 5 is a side elevational view of a prior art recess former in its open 20 configuration to accept a planar anchor before being attached to a mould. Fig. 6 shows the prior art recess former of Fig. 5 closed about the planar anchor and mounted on the mould. Fig. 7 is an exploded perspective view of a prior art recess foermr and a round bodied lifting anchor Fig. 8 shows the prior art recess former of Fig 7 closed about the anchor. Fig. 9 is a side elevation of the prior art recess former and anchor of Fig, 7, Fig, 10 is a side elevational view of a prior art recess former in its open configuration to accept a round bodied anchor before being attached to a mould, Fig. I1 shows the prior art recess former of Fig. 10 closed about the round 30 bodied anchor and mounted on the mould, Fig, 12 is a perspective view of a first embodiment of the recess former of the present invention and a co-operating planar bodied lifting anchor, 5 750-At 4 Fig. 13 is a perspective view of a one half of a recess former of a second embodiment, Fig. 14 is a longitudinal section of the recess former of Fig. 12, with the recess former shown in its open configuration, with a side elevational view of a co 5 operating planar lifting anchor, Fig. 15 shows the recess of Fig. 14 closed about the anchor, Fig. 16 is a longitudinal section of a recess former comprising two half sections as shown in Fig. 13 with a side elevational view of a co-operating planar anchor, before the recess former halves have been attached to the anchor, 10 Fig. 17 shows the two half recess parts of Fig 16 closed over the anchor, Fig. 18 is a side elevational view of a third embodiment of a recess former designed for co-operation with a round bodied anchor, with the recess former shown in the open position before being attached to the anchor, Fig. 19 shows the recess former of Fig. 18 closed about the head of the anchor, 15 Fig. 20 is a side elevational view of a fourth embodiment of the recess former and anchor shown in Fig 18 in which the recess former takes the form of two separable parts designed for placing anchors in concrete pipes, Fig. 21 is a side elevational view of an attachment frame for use with the recess former shown in Fig.20, 20 Fig. 22 is an inverted plan view of the attachment frame shown in Fig 21, and Fig 23 is a side elevational view of the recess former and co-operating anchor placed within the attachment frame shown in Fig. 20 and attached to the reinforcing elements of the concrete pipe. 25 Detailed Description Turning now to Figs. 1 to 4 a prior art recess former 10 which is widely used in Australia is shown in the drawings. The recess former 10 has a truncated semi spherical shape formed in two halves 11 A and 11 B hinged about the centre 12 and separated by a transverse slot 13 which receives the attachment end 14 of a lifting 30 anchor 15. The two halves 11 A and 1 1B are joined through a bridging section 16 which is flexible and acts as the hinge about the centre 12. A pair of lugs 17 and 18 protrude from the interior walls 19 of the transverse slot 13 towards one another within the slot 13 and engage with a transverse aperture 20 of the lifting anchor 15. The engagement of the pair of lugs 17 and 18 provides a mechanical interlock with 51750-AU & NZ 5 the lifting anchor 15 which restricts the anchor 15 from moving or being dislodged from the former 10 during casting of a concrete element 30 (Fig. 4) and positions the anchor 15 in the correct alignment for connection to a lifting shackle (not illustrated) through the transverse aperture 20. 5 As seen in Figs 5 and 6, the prior art recess former 10 is fitted with means of bolting it to the surface of the mould wall 31 or formwork used to cast the concrete 30, e.g. by passing a bolt or bolts 32 through the mould wall 31 which extend into the semi spherical halves I 1A and 11 B of the body of the recess former 10 into which they are 10 attached by threaded inserts 21 (Fig, 1). The purpose of the attachment bolts 32 is to firstly position the recess former 10 into the correct orientation for the lifting of the concrete element, and secondly to also mechanically close the recess former 10 about the end of the anchor 15. 15 The two halves 11 A and 11 B of the recess former 10 are hinged about the centre 12 of the recess former 10 and when the recess former 10 is pulled back towards the mould wall 31 by the attachment bolts 32, this causes the two halves 11A and 1 1B of the recess former 10 to close onto the anchor 15. Additionally this rotation and closing action of the two halves 11 A and 11 B of the recess former 10 causes the lugs 17 and 20 18 located on the inside walls of the slot 13 in the recess former 11 A to enter the transverse aperture 20 of the lifting anchor 15. When the bolts 32 are drawn through the mould wall 31, the two halves 11A and 11 B of the recess former 10 are maintained in the closed position, firmly gripping the anchor 15. 25 Another type of prior art recess former 50 is shown in Figs 7-11. This type of recess former is substantially similar to the recess former 10 however it is designed to co operate with a round bodied anchor 60 comprising a forged head section 61 and a cylindrical body 62 of lesser diameter. 30 The recess former 50 is of a hemispherical shape formed in two halves 51A and 51B hinged in the centre 52, and separated by a transverse slot 56 which receives the attachment end 61 of a lifting anchor 60. The interior cavity 53 is shaped to receive the enlarged head 61 and lesser body 62 of lifting anchor 60 and restricts the anchor 51750-AU & NZ 6 60 front moving or being dislodged from the former 50 during casting of a concrete element. Figs 10 and 11 depict how the anchor 60 is fitted into the recess former 50 and then 5 attached to the mould wall 31 by mounting bolts 32 fitted into receiving nuts 21 in each half Sl A and 51B of the recess former 50. When the bolts 32 are drawn through the mould wall 31, the two halves 51A and 51B of the recess former 50 are maintained in the closed position, firmly gripping the anchor 60. 10 A principal disadvantage of the prior art recess formers 10, (50) is that they require mechanical attachment to the wall of the mould to ensure complete closure of the two halves 11A, 11B (51A, 51B) about the anchor 15 (60). This attachment is usually provided by means of bolts 32 passing through holes 15 drilled through the mould wall 31. It is often convenient to use the same mould for manufacture of concrete components of differing dimensions necessitating different anchor positions. A significant disadvantage for the user is that the bolt holes in the moulds must be stopped when the recess former 10 (50) are moved away from the previously used positions. As a consequence the mould wall elements need to be 20 drilled with a multiplicity of holes for the attachment bolts which results in degradation in the quality of forms and the products cast against them, This is time consuming and has obvious cost implications for manufacturers and may result in a poor quality finish of the concrete component at the position of the stopped holes as a result of imprinting of the holes or their stopping material upon the concrete cast 25 against them. Furthermore, new types of lightweight formwork for moulds made of extruded aluminium hollow sections are becoming popular and are not suitable for through drilling for the attachment of recess formers for lifting anchors. 30 In the discussion below, particular reference is made to anchors 15 and recess formers 10 however the comments are equally applicable to other types of prior art recess formers 50 and anchors 60. 51750-AU &NZ 7 The placement of anchors 15 and recess formers 10 in the mould with respect to other reinforcing elements often results in forces being transmitted through the anchors 15 to the recess farmers 10 which prevent the complete closure of the recess farmers 10 about the anchor 15. Such forces commonly result from leverage developed between 5 the anchor 15 and reinforcing steels, and/or movement under self-weight of the anchor 15 and its attached reinforcing elements, and/or the forces applied during the pouring and settling of the concrete. These forces may prise open the recess former 10 during the casting process thereby creating spaces between the anchor 15 and the recess former 10 which permit the entry of cement laden waters or cement paste into the 10 interior cavity 13 of the recess former 10. These problems become more significant when the dimensions and mass of the anchors 15 are increased to an extent where the mass of the anchors 15 themselves may be sufficient to force open the recess former as a result of leverage caused by the 15 anchor 15 cantilevering under its own weight about the wall of the mould 31 to which it is attached by means of the recess former 10. In such cases it would be desirable to allow the former 10 to be closed around the anchor head but not physically attached to the mould 31, thereby eliminating the need 20 for attachment holes to be provided in the mould wall 31. This is not practically possible with the prior art recess farmers 10 because the hinged halves 11A and I1B of the recess formers 10 are free to open even under minor loads and/or vibrations unless restrained by a pulling force applied between the mould 31 and the body of the recess former 10. 25 After the concrete 30 has hardened, the mould 31 and recess former 10 are removed thereby exposing the attachment end of the anchor 15 inside the recess formed by the removal of the recess former 10. 30 When using the prior art recess former 10 as described above, cement which has flowed into spaces between the recess former 10 and the anchor 15 makes the connection of the lifting shackle or other attachment device difficult or impossible. Where cement has hardened inside the transverse aperture 20 it prevents the connection of the attachment device. This cement is extremely difficult to remove 51750-AU & NZ 8 because the aperture is normally located below the surface of the concrete. The removal of the hardened cement is impeded by the confining space of the walls of the recess, 5 What is desirable is a method of casting a recess around the anchor, and of retaining the anchor tightly in its correct position in such a way that the integrity of the recess is not compromised during the casting process and which guarantees that after removal of the recess former that the attachment aperture will be clean and free of cement or other fouling materials. Additionally a recess former which may be closed around the 10 head of the anchor and which does not require an outside closing force to enable it to remain properly intact would be of great benefit to modem production facilities where it is not desirable to damage the walls of the mould by drilling or other attachment means. 15 Turning now to the first embodiment of the present invention illustrated in Figs. 12, 14 and 15, a recess former 70 having a truncated semi-spherical shape is formed in two halves 71 A and 71 B with a slot 73 adapted to receive the attachment end 81 of a lifting anchor 80. A central section 72 which is flexible acts as the hinge. The inside walls 77, 78 defined by the slot 73 in the two halves 71A and 71B each have a cavity 20 74 in the interior surfaces 77 and 78 of the slot 73. A plug 83 is fitted into a transverse aperture 82 of the lifting anchor 8. The ends of the plug 83 are shaped to engage with a frictional fit in the corresponding receiving recesses 74 of the recess former 70 when the recess former 70 has been closed about 25 the anchor head 81. The plug 83 is typically fabricated from rubber or other non magnetic material in this embodiment. Magnets or ferromagnetic implants 76 are moulded into internal walls 77, 78. The magnetic or ferromagnetic implants are arranged in such a way so as to either 30 magnetically attract each other or to magnetically attract a ferromagnetic anchor 80 located within the slot 73. When the two halves 71A and 71 B of recess former 70 are magnetically clamped onto the anchor head 81, the plug 83 locates in the cavities 74 and provides a mechanical 51750-AU & NZ 9 interlock between the anchor 80 and the the recess former 70 which prevents the anchor 80 from being dislodged from the recess 70. It will be appreciated that only a relatively small magnetic force is required to clamp 5 the anchor 80 to the recess 70, and when used in conjunction with the secondary mechanical interlock between the plug 83 and the recess former 70, a large dislodgement force can be resisted between the anchor 80 and the recess 70. A secondary ridge 75 protrudes from the faces 77 and 78 below the location cavities 10 74. This ridge is designed to enter and engage with the transverse slot 84 below the lifting aperture 82 in which is located the plug 83 of the anchor 81. When the recess 70 is magnetically clamped to the anchor 80, the secondary mechanical interlock is enhanced between the anchor 81 and recess former 70 by the mechanical interference between the plug 83 and the ridges 75. 15 In other modifications, not illustrated, the plug 83 is magnetic or ferromagnetic. Thus, the plug 83 and recess former 70 are held together by means of magnetic attraction between a magnetic or ferromagnetic plug 83 and magnetic or ferromagnetic implants embedded within the halves 71A, 71B. 20 For both these arrangements the assembly (of the magnetically clamped and interlocked recess former 70 and anchor 80) is able to be located in the casting mould without fixing or bolting it to the mould wall 31. In practice such assemblies are located close to, or touching, the mould wall 31 but without fixing. Such "floating" 25 assemblies eliminate the need to drill or damage the mould and provide flexibility in the physical location of the anchor assemblies with differing panel dimensions. Figs. 13, 16 and 17 show a second embodiment of one half of a recess former 90 formed from two substantially identical hemispherical parts 90A and 90B. 30 In addition to the magnetic or ferromagnetic implants 76, a magnetic element 79 is positioned so as to magnetically clamp to the same element 79 in the opposite recess former half 90A, 90B and also to the top of the anchor head 81. One pole of each magnet is attracted to top surface of the head of the anchor 81 and the other pole lies in the plane of the mould wall, making it possible to attach the assembly magnetically 51750-AU & NZ 10 to a ferromagnetic mould or a magnet or ferromagnetic element beyond a non ferromagnetic mould wall, e.g. a magnetic clamp positioned outside and adjacent to the mould wall. Such arrangements are useful for positioning anchors and recesses against a mould wall but without requiring through-penetration of the wall to position 5 a bolt or other fixing device. Figs. 18 and 19 show a third embodiment of a recess former 150 adapted for use with round bodied anchors 60. This recess former includes magnetic implants 176 and 177 within the cavity 153 in each of the hemispherical halves 15 1A and 15 lB. 10 It can be seen that this recess former and anchor co-operate in an analogous manner to the recess and anchor shown in Figs. 14 and 15 used with planar anchors. The magnetic implants 176 and 176 clamp the two halves 151A and 151B to the anchor body 62. The enlarged anchor head 61 is mechanically interlocked in the shaped cavities 153 within each half 151A and 151B of the recess former 150 and prevented 15 from dislodgment whilst the halves 151 A and 151 B are magnetically clamped to the anchor 60. Figs. 20-23 show a fourth embodiment of the recess former 150 adapted for use with round bodied anchors 60. This recess former 150 takes the form of two separable 20 parts 151A and 1511B which are able to be closed about the head 61 of the anchor 60. The recess 150 is magnetically clamped by the embedded magnets 176, 177 within the parts 151B and 151A, to the shaft 62 of the anchor 60 and interlocked by the internally shaped cavity 153. The surface 178 of the recess former 150 is curved and outwardly convex so as to fit closely with the wall of a pipe mould 190 (only part of 25 which is illustrated). The recess former is fitted into a surrounding frame 180 preferably made of plastics material. The frame 180 takes the form of a substantially closed ring section 181 from which extend arms 182 provided with one or more clips 183 to enable the frame 180 to be attached to the reinforcing wires 184 of the pipe prior to casting. This provides a useful means of retaining the anchor 60 and recess 30 former 150 and reinforcing in the optimum position relative to the wall of the pipe mould 190 during casting of the concrete pipe. The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the concrete arts, can be made thereto 51750-AU & NZ 11 without departing from the scope of the present invention. For example, the magnetic elements can be electromagnetic rather than the permanent magnets illustrated. The term "comprising" (and its grammatical variations) as used herein is used in the 5 inclusive sense of "including" or "having" and not in the exclusive sense of ''consisting only of'. 51750-AU & NZ