MACHINE FOR MANUFACTURING METAL CAGES
[01 ] The present invention regards a machine for manufacturing metal cages for reinforced concrete.
 It has been known that for manufacturing the reinforcement of piles, reinforced concrete pillars and the like, metal cages are used, often of cylindrical shape, consisting of a series of longitudinal bars outside which is spirally wound a metal wire, according to a suitably predefined pitch. The longitudinal bars are distributed according to a suitable geometrical profile, usually cylindrical. Nevertheless the use of piles and pillars having different geometries has also been known, for example with asymmetric, elliptic, prismatic reinforcement and the like.
 In order to manufacture such metal cages are currently used machines which al low to weld the spiral on the longitudinal bars, prearranged according to the desired geometrical profile. According to a known solution, cage making machines generally provide at least two rotating members, also called matrixes, at which are positioned the longitudinal bars according to the desired profile. For exam ple patent EP 00035477 discloses a machine for manufacturing cages with spiral winding comprising a drive flange and a free-turning flange, drawn in rotation or motor driven as well, carried by a trolley which can move in front of the fixed flange; both flanges have a plurality of holes arranged in concentric circles for positioning the longitudinal bars.
 A different known solution provides to spirally wind the metal wire on the bars providing the same wire with a shift movement along the axis of the form ing cage, whi le a simultaneous rotation motion according to the aforesaid axis is given to the longitudinal bars, arranged according to a predetermined geometrical profile.
 As an example patent IT 1216960 illustrates a method of manufacturing cylindrical cages for reinforced concrete which provides to insert the longitudinal bars destined to shape the cage through three disks arranged coaxially, provided with radial holes for the passage of the bars; the disks are rotatable about the same longitudinal axis. More precisely, the machine destined to carry out the method provides two end disks and one intermediate disk mobile on a trolley along suitable longitudinal guides. The bars are fixed at one end at a first end disk and cross suitable guides associated with the intermediate mobile disk. To shape the cage, the bars are set in rotation while the metal wire, unwound from a lateral coil and brought in longitudinal motion, progressively spirally winds on the same bars.
 T h e ca g e making machine illustrated in patent application PS2001A000012, wherein is illustrated a mobile head actuated in shift motion with respect to a fixed head carrying the end of the longitudinal bars, and cooperating with articulated supports for supporting the bars suitable to move downward in order not to interfere with the same mobile head during the aforesaid shift motion, belongs to the same typology.
 The cage making machine illustrated in patent application UD2004A000095 operates in a sim ilar manner. Such a machine comprises a fixed head
provided with rotating members with which are associated the ends of the longitudinal bars, a motor driven mobile head supporting a device for welding the tightening rod to the longitudinal bars, and one or more support trolleys suitable to support the tracts not yet welded of the longitudinal bars. Nevertheless the above said machines do not solve the problem of manufacturing metal cages for reinforced concrete in a simple and efficient manner, in particular with respect to the considerable dimensions of such machines. In fact it is to be observed that the known machine generally provide a carrying structure having massive weight and large dimensions, in particular due to the structures for supporting the matrixes which also imply a notable height of the machines, in addition to the considerable longitudinal dimensions.
Th e dimensions of the structure and, as a consequence, its costs considerably increase with respect to the maximal dimensions of the reinforcements that the machine must be able to manufacture.
The notable dimensions and weight of the carrying structure also affect the transport and mounting of the machines, as harmful rotations of the matrixes caused by the considerable inertia can happen, in addition to requiring suitable apparatuses for their handling.
The task of the present invention is that of solving the aforementioned problems, devising a machine which allows to manufacture in an optimal way metal cages for reinforced concrete also of large dimensions.
Within such task, it is a further scope of the present invention that of providing a machine for manufacturing metal cages provided with high
 Another object of the present invention is that of providing a machine for manufacturing metal cages having a simple conception, a securely reliable functioning and versatile use, as well as relatively economic cost.
 The cited scopes are attained, according to the present invention, by the machine for manufacturing metal cages according to claim 1 .
 According to the present invention, the machine for manufacturing metal cages comprises rotating means suitable to bring in rotation a plurality of longitudinal bars in the fixing position for forming the cage and supported by support means suitable to leave the peripheral zone of the same rotating means free.
 Suitably the aforesaid support means are arranged according to the rotation axis of said rotating means and are suitable to be actuated in rotation by respective motor members.
 According to a preferred embodiment, the machine comprises an operating station, having a fixed position and provided with a first rotating member suitable to support passing a plurality of longitudinal bars in the fixing position for forming the metal cage, and a mobile head, suitable to be actuated with a shift motion in a direction axial to said forming cage and provided with a second rotating member to which are made integral respective ends of said bars. Respective motor members are suitable to actuate in synchronous rotation the rotating members of the fixed station and of the mobile head, in suitable phase relation with the shift motion of the mobile head. The rotating member of the fixed station is carried by an axial shaft, carrying integral at least one element for supporting the bars
and suitable to be actuated in rotation by a respective motor member.
 Preferably the rotating member of the fixed head is carried suspended at one end of said axial shaft, which axial shaft is actuated in rotation at the opposite end by said motor member.
Description of Drawings
 Details of the invention shall be more apparent from the detailed description of a preferred embodiment of the machine for manufacturing metal cages according to the present invention, illustrated for indicative purposes in the attached drawings, wherein:
 f i g u re 1 s h ows an overall perspective view of the machine for manufacturing metal cages for reinforced concrete according to the present invention;
[21 ] figure 2 shows an overall perspective view of the machine in hand from a different angle;
 figure 3 shows a perspective view of an operating station of the machine having fixed position;
 figures 4 and 5 respectively show a perspective view of members associated with said fixed station of the machine;
 figure 6 shows a perspective view of the mobile head of the machine.
 With particular reference to such figures, the machine for manufacturing metal cages for the reinforcement of piles, reinforced concrete pillars and the like, is indicated in its entirety with 1 . In a known manner, the metal cage to be manufactured consists of a series of longitudinal bars arranged parallel and made integral, according to a predetermined geometry, by
means of a metal wire spirally wound on the same bars. The metal wire is fixed externally to the bars manually or by means of a suitable union device preferably through welding.
 The metal wire is fed from a coil, carried by a reel 2, arranged preferably laterally to the machine 1 , as better described in the following.
 The machine 1 comprises an operating station 10 which is fixed during the formation of the cage and is provided with a first rotating member 1 1 suitable to support slidingly passing, in the exact fixing position, the longitudinal bars destined to form the cage. The operating station 10 is arranged in a position substantially median longitudinally to the fixed framework of the machine 1 .
 Downstream of the operating station 10, according to the feed direction of the forming cage, is arranged a mobile head 20, suitable to be actuated with a shift motion in a direction axial to the forming cage. The mobile head 20 is provided with a second rotating member 21 to which are suitable to be made integral respective ends of the longitudinal bars supported slidingly passing by the first rotating member 1 1 .
 The rotating members 1 1 , 21 , also called matrixes, are suitable to bring in rotation the longitudinal bars during the formation of the cage.
 In the illustrated case, the rotating member 1 1 , 21 are constituted by rings arranged on vertical planes and rotatable accord ing to the same longitudinal axis, substantially horizontal. The rings 1 1 , 21 have a plurality of rad ia l s lots 1 3 , 23 , extended outwards , at which are mounted corresponding sleeves 14, 24 for the longitudinal insertion of the bars (see in particular figures 3 and 6). Preferably the radial slots 13, 23 are made by
respective clamping members of the sleeves 14, 24, constrained in a removable way to the rings 1 1 , 21 through suitable fixing means. Nevertheless it is possible to provide that the aforesaid rotating members have a different shape, for example consisting of disks having a plurality of holes or slots, distributed on the whole surface, with which are suitable to be associated the cited sleeves. In practice matrixes of various shapes can be provided for producing metal cages having prismatic, elliptic or specially shaped section, on the basis of the specific requirements of the users.
[31 ] More precisely, the front ends of the longitudinal bars are made integral to the sleeves 24 associated with the ring 21 of the mobile head 20, by means of suitable tightening means, for example screw means; instead the longitudinal bars are inserted passing and freely sliding through the sleeves 14 associated with the ring 1 1 of the fixed station 10.
 The mobile head 20 provides a frame 22 which is suitable to support rotatable the ring 21 about the cited longitudinal axis; the frame 22 is mobile along a track 3 shaped longitudinally to the fixed framework of the machine. To this aim, the ring 21 of the mobile head 20 has a central hub 25 which is suitable to be constrained in axis to a motor member 26, carried by a framework 27 of the frame 22 according to the longitudinal axis of the machine (fig. 6). It is obviously possible to provide that the ring 21 is brought in rotation in a different manner, for example through suitable motion transmission members.
 The mobile head 20 is suitable to be actuated with a shift motion in a direction axial to the forming cage upon control of further motor members 28 mounted on the frame 22. Such motor members 28 suitably bring in
rotation a couple of cogwheels which engage correspond ing racks constrained longitudinally to the track 3, not represented for simplicity.
 The ring 1 1 of the fixed head 10 has a central hub 15 which is suitable to be constrained in axis to a relative motor mem ber, as described in the following.
 The longitudinal bars are further supported sliding, for the part protruding upstream of the fixed station 10, by means of a series of support elements
30 arranged suitably distanced in a direction axial to the forming cage, at the side opposed to the side directed towards the mobile head 20. The support elements 30 are provided with a rotatable part preferably radially shaped 31 and arranged coaxially to the rings 1 1 , 21 of the fixed station 10 and of the mobile head 20, on parallel vertical planes. In the illustrated case there are provided five support elements 30 arranged in series on parallel vertical planes, but obviously it is possible to provide the use of a different number of support elements according to the specific exigencies.
 More precisely, the support elements 30 respectively provide a frame 32 shaping a cradle 33 having the shape of a circular sector, in which is guided the rotatable element 31 (fig. 5); the cradle 33 is suitably provided with a coating of material having a low friction coefficient. The rotatable element
31 consists of a series of rods 34 which extend radially, in angularly distributed positions, from a circular-shaped central body 35 (fig. 4). The rods 34 carry at their end a roller 36 freely rotatable according to an axis parallel to the axis of the same rotatable element 31 ; it is possible to provide that only a part of the rods 34 of the rotatable element, for example in an alternated manner, is provided with such a roller 36. Suitably the
cradles 33 are respectively provided, beside, with a support profile 37 having as well the shape of a circular sector, with a curvature radius different from the cradles 33, on which the longitudinal bars rest during the rotation.
 The central body 35 of the rotatable elements 31 is made integral to a shaft 40 which extends according to the longitudinal axis of the machine, at the opposite side of the fixed station 1 0 with respect to the side directed towards the mobile head 20; the axial shaft 40 is preferably realized in circular section tubular shape. Such an axial shaft 40 is made integral at an end, through a flange junction member 43, to a tubular portion 41 of corresponding section, shaped axially protruding from the central hub 15 of the ring 1 1 of the fixed head 10, in a way as to allow to bring in rotation the same ring 1 1 during the formation of the cage.
 At the opposite end, the shaft 40 is connected to a motor member 46 carried by a fram ework 47 of a relative fram e 42 accord ing to the longitudinal axis of the machine; the frame 42 is constrained to the structure of the machine in a fixed position. In practice the rotating member 1 1 of the fixed head 10 is carried suspended at one end of the shaft 40 carrying the rotatable elements 31 , actuated in rotation at the opposite end by the motor member 46.
 Longitudinally to the apparatus, in a position median to the track 3, are provided a series of support members 50 of the forming metal cage suitable to be lifted after the passage of the mobile head 20. In the illustrated case three support members 50 are provided, suitably distanced from one another, but it is obvious that it is possible to use one or more of such
support members according to the dimensions and the weight of the metal cage to be manufactured. The support members 50 are substantially constituted by a couple of longitudinal development rolls 51 , placed side by side at suitable distance, arranged parallel to the formation axis of the cage (fig. 3). The rolls 51 are carried rotatable according to their own axis by a lifting member 52 which can be lifted upon control of a respective actuator member.
 Preferably the machine is provided, at the fixed station 1 0, with union means consisting of a welding device 5 suitable to automatically make the welding of the metal wire which unwinds from the reel 2 to the longitudinal bars (fig. 3). The welding device 5 is suitably carried at the top of a column 4 which extends beside the operating zone of the rotating member 1 1 of the fixed head 10. Obviously it is possible to provide that the welding is realized manually or alternatively to provide the use of union means of different type.
[41 ] The functioning of the drawing assembly turns out to be easy to understand from the preceding description.
 In the initial step of the formation cycle of a metal cage, the mobile head 20 is arranged beside the fixed station 10 substantially at a central operating zone of the machine. The longitudinal bars 8, suitably prearranged on a plane defined by the frames 32 at the side of the cradles 33, are made roll and kept separated, to avoid undesired entanglement, in the rods 34 of the rotatable elements 31 of the support elements 30, to be successively inserted in respective coaxial sleeves 14, 24 of the rings 1 1 , 21 , according to the predefined geometry of the transverse profile of the cage to be
manufactured. In particular, the bars are inserted passing through the sleeves 1 4 associated with the ring 1 1 of the fixed station 1 0, and successively fixed at the front ends to the corresponding sleeves 24 of the ring 21 of the mobile head 20, through the provided fixing means.
 I n practice , at the end of the load step, the bars result arranged longitudinally parallel according to the transverse profile of the cage to be manufactured, fixed at a front end to the rotating member 21 of the mobile head 20, slidingly passing through the rotating member 1 1 of the fixed head 10 and supported for the part protruding at the back from such a fixed head 10 resting between the rods 34 of the rotatable elements 31 of the support elements 30.
 At this point the operator performs the union preferably through manual welding of the first joint between the metal wire which unwinds from the reel 2 and one of the longitudinal bars 8 and then controls the beginning of the formation cycle of the cage. If the machine is provided with its own welding device 5, arranged at the fixed station 10 as illustrated, the cycle proceeds automatically without any further intervention of the operator. The fixed structure of the machine is suitably provided, beside the fixed station 10, with a superelevated platform 6, from which the user can easily control the formation of the metal cage, also with the help of suitable handling instruments 7 (fig. 3).
 In phase of formation of the cage, the rotating members 1 1 , 21 are actuated in rotation, in suitable phase relation, respectively by the motor member 46 associated with the shaft 40 of the rotatable elements 31 and by the motor member 26 mounted on the mobile frame 22, while the mobile head 20 is
simultaneously actuated with a shift motion. In such a way is determined the spiral winding of the metal wire, which unwinds through suitable straightening members, about the longitudinal bars 8, brought in rotation by the rotating members 1 1 , 21 . In combination with the shift impressed by the mobile head 20 is therefore generated a helical movement which allows to wind the external wire according to a spiral shape.
 Simultaneously the rotatable elements 31 of the support elements 30 are brought in synchronous rotation by the axial shaft 40, accompanying in such a way the rotation of the rotating members 1 1 , 21 . The rotatable elements 31 are supported radially through the relative rollers 36 which slide in the respective cradles. It is to be observed that the rotatable elements accomplish the double function of separation and support of the longitudinal bars and of support of the pile which brings them in rotation.
 In a suitable phase relation, the lifting of the support members 50 is operated to support the part of the metal cage already shaped. In particular the rolls 51 of the support members 50 are taken in the lifted position after the passage of the mobile head 20.
 At the end of the formation cycle of the cage, the mobile head 20 is distanced from the fixed head 10 of a tract substantially equal to the length of the cage. A further advancement of the mobile head 20 is then operated to free the back end of the cage at the fixed station 10. Then is operated the unlocking of the longitudinal bars from the sleeves 24 and the mobile head 20 further shifts, in order to leave the cage resting on the only support members 50. At this point the manufactured metal cage can be drawn by means of suitable lifting means or be unloaded in another way, for example
through rolling after having lowered the support members 50.
 The machine according to the present invention attains the scope of manufacturing in an optimal manner metal cages for reinforced concrete, even of large dimensions. In particular the machine in hand allows to easily manufacture metal cages also of large dimensions shaped in any way with a relatively light structure having reduced dimensions.
 Such a result is obtained substantially thanks to the inventive idea of supporting all the rotating means which bring in rotation the longitudinal bars in the fixing position for form ing the cage through support means suitable to leave free at least a part of the peripheral zone of the same rotating means. In particular, the invention provides to make the rotating member 1 1 of the fixed station 10 integral to an axial shaft 40 suitable to be actuated in rotation by a suitable motor member 46 and also bringing in rotation the rotatable elements 31 of the support elements 30. In other words, the rotating member 1 1 of the fixed station 10 does not require an external support structure, but is supported in rotation by the shaft 40 of the rotatable elements 31 of the support elements 30. On this matter it is to be observed that the welding device 5 is provided with its own separated support structure. The rotatable elements 31 , as previously mentioned, are supported radial ly through the relative rol lers 36 which sl ide in the respective cradles.
[51 ] Thanks to this, the carrying structure of the machine is sensibly simplified and has relatively reduced weight and dimensions. The rotating members for handling the bars, in phase of formation of the cage, are in fact carried overhang by the motorization members and do not provide support
structures of large dimensions, heavy and complex. In practice, the carrying structure of the machine consists of a track framework arranged leaning on the floor.
 The machine therefore results easier to transport and to operate, further to presenting a proportionally reduced cost. In particular the matrixes are not carried rotatable inside costly support structures, which turns out to be particularly advantageous in phase of transport and mounting, further than for the minor costs. This enables an easier transfer thereof on the yards.
 The reduced structure of the machine further allows an easier control of the productive phases and a simpler unload of the produced metal cages.
 An advantageous characteristic of the machine is to enable a h igh productivity with a very reduced workforce engagement.
 It is to be observed that during the formation of the cage the tracts of bars not yet fixed rotate about the aforesaid axis, thanks to the support elements 30 from which the bars are carried in angularly distributed positions. In such a way the risk of interlacing or overlapping of the bars for the not welded portion is avoided.
 The machine described for indicative purpose is susceptible of various modifications and variants according to the various exigencies. In the illustrated case, the bars destined to form the metal cage are arranged accordi ng to a circu lar transverse profi le, so as to determ ine the manufacture of a cylindrical pile. Obviously it is possible to provide the manufacture of cages having a different transverse profile, for example elliptic, polygonal, with asymmetric distribution of the bars or the like.
 Furthermore the machine could be provided, in a known way, with a
different number of matrixes or anyway with different rotating means suitable to bring in rotation the longitudinal bars in fixing position for forming the cage.
 It can be also provided that the operating station in which is realized the union of the metal wire to the longitudinal bars is mobile as well and not fixed as in the case illustrated for indicative purpose.
 In practice, the embodiment of the invention, the materials used, as well as the shape and dimensions, may vary depending on the requirements.
 Should the technical characteristics mentioned in each claim be followed by reference signs, such reference signs were included strictly with the aim of enhancing the understanding the claims and hence they shall not be deemed restrictive in any manner whatsoever on the scope of each element identified for exemplifying purposes by such reference signs.