EP2412456B1

EP2412456B1 - System and method for handling metal bars

Info

Publication number: EP2412456B1
Application number: EP11175822.3A
Authority: EP
Inventors: Stefano Peruzzo
Original assignee: Oscam Srl
Current assignee: OSCAM Srl
Priority date: 2010-07-30
Filing date: 2011-07-28
Publication date: 2018-01-03
Anticipated expiration: 2031-07-28
Also published as: ITTO20100662A1; IT1401607B1; EP2412456A1

Description

The present invention relates to systems for the treatment of metal bars, in particular bars for the reinforcement of concrete, of the type comprising:

at least one operating unit, such as, for example, a bending unit or a cutting unit; and
a device for picking up and transferring bars, for feeding a plurality of bars to the operating unit by picking them up in any desired predetermined number from a bundle of bars deposited in a magazine and separating them from the remaining bars of the bundle.

A device for transferring metal bars of the type specified above is, for example, described in the patent No. IT-B-1 351 915 , filed in the name of the present applicant. Systems for automatic loading of metal bars onto machines designed to carry out operations of various types on said bars are known from a wide range of documents, such as, for example, DE-AS- 1 101 336 , IT 1 206 893 , EP-A-1 356 875 , EP-A-1 356 876 , EP-A-1 980 341 , EP-A-2 172 287 , WO2007/043089A1 , US4471819A , AT-B-393 641 , or from EP-A-1 927 412 on which the preamble of the independent claims 1 and 14 is based. A further device of the type specified above is known from EP-A-2 374 553 , filed in the name of the present applicant on April 12, 2010 and not yet rendered public at the date of filing of the present disclosure. The object of the present invention is to provide automatic loading of a predetermined number of metal bars onto an operating unit, guaranteeing that said operation is performed in a reliable, proper, and orderly way and using means that involve the occupation of a minimum portion of space in plan view, above all in the longitudinal direction of lie of the bars.
With a view to achieving said object, the subject of the present invention is a system according to Claim 1 and a method according to Claim 14. Further advantageous characteristics of the invention are specified in the annexed dependent claims.
The invention will now be described with reference to the annexed drawings, which are provided purely by way of non-limiting example and in which:

Figures 1A and 1B are schematic plan views that show two different operating steps of a system for bending metal bars, in itself of a known type, which receives the bars to be bent from an automatic feed device built according to the present invention;
Figure 1C is a cross-sectional view of one of the two bending machines forming part of the system illustrated in Figures 1A, 1B, which is also according to a simplified representation;
Figure 2 is a cross-sectional view of a part of the system that is to feed bars to bending machines;
Figures 3-12 are schematic views that illustrate successive operating steps of the device for picking up and automatically transferring the bars, which is located upstream of the device of Figure 2;
Figure 13 is a schematic view at an enlarged scale of a detail of the system of Figures 3-12; and
Figures 14-22 are schematic views that illustrate successive operating steps of a second embodiment of the device for picking up and automatically transferring the bars that is located upstream of the device illustrated in Figure 2.

In Figures 1A, 1B, the reference number 1 designates as a whole a system for bending metal bars, in itself of a known type. Figures 1A, 1B are both plan views of the system 1, which comprises two bending units 2 (see also Figure 1C), which each include a supporting structure 3, rotatably mounted on which is a bending disk 4 having a central spindle 5 and carrying an eccentric pin 6 for bending a portion of one or more bars B around the central spindle 5. In the specific example illustrated, the axis 4A (Figure 1C) of the bending disk 4 is inclined with respect to the vertical direction. However, it would be equally possible to envisage that said axis is oriented vertically or horizontally, as is likewise well known in the art. With reference once again to Figure 1B, during bending of one or more bars B the portion of the bar or bars, adjacent to the part that is bent comes to rest against a contrast element 7, carried by the structure 3 of the machine, which is illustrated in a purely schematic way in the figures referred to.
As is evident from Figure 1C, the two bending units 2 define a space 8 for receiving the bars to be bent, in which a number of bars can be received on top of one another in a plane orthogonal to the plane of bending of the bars. Once again with reference to Figure 1B, in the case of the example illustrated, the two bending units 2 are mobile on rails 9 in the direction L parallel to the longitudinal direction of lie of the bars B. Alternatively, as is already known in the art, it is also possible, for example, to envisage just one bending unit mobile in the direction L, and one bending unit set fixed in said direction, or else just one bending unit or finally even more than two bending units. Typically, once again according to a technique in itself known, provided within the casing 3 of each bending unit are motor means designed to govern movement of the bending unit along the rails 9. Moreover, the system for the treatment of metal bars is provided with an electronic control system, which governs, according to a pre-set program, the successive movements of the bending units 2 and of the corresponding bending disks 4 to obtain the different bends of a bar or of a set of bars subjected simultaneously to bending, with a view to obtaining any predetermined shape.
The bending units 2 can be of the type illustrated in Figures 1A and 1B, with a spindle 5 around which the bars are bent and with the contrast element 7, or else of the type with a spindle having a diametral slit that defines also the space for receiving the bars. In this latter case, one of the portions will possibly function also as contrast element. Figure 1A shows the bar or bars positioned above the bending units prior to execution of a bending operation, whilst Figure 1B shows the two bending units after the bending disks 4 have been rotated simultaneously through 90° to provide two bends at right angles at the ends of the bar or bars B.
Of course, the bending system 1 is illustrated herein with reference to the preferred embodiment of the invention, in which the device for automatic picking-up and feed of the bars is used for feeding the bars to said bending system. However, as will emerge clearly also in what follows, the automatic device for picking up and loading bars that forms the subject of the present invention is likewise usable for feeding any predetermined number of bars also to operating units of a different type, for example, a unit for cutting bars into pieces of desired length or also for feeding the bars to a further waiting station, from which they are picked up only subsequently to be sent on for further treatments.
Figure 2 shows at an enlarged scale and in lateral view an embodiment of the stationary structure 30 moving on which are the two bending units 2, which define an inclined surface P coinciding with the plane of bending of the bars defined by the two bending units. Also visible in Figure 2 is one of the two contrast elements 7 associated to the two bending units. The structure 30 carrying the two bending units 2 is set alongside a further stationary bench 10 carrying a chain-driven feed device 14 for feeding the bars to the receiving space 8 defined by the two bending units. For this purpose, the stationary structure 10 supports, in an articulated way, a longitudinal distribution of transverse arms 11 defining an inclined surface Q via which the bars B are made to roll by gravity until they reach the receiving space 8 defined by the bending units. A characteristic of the system according to the embodiment illustrated herein lies in the fact that it is able to pick up from a magazine (illustrated in greater detail in what follows) a predetermined number of bars and to feed said bars one after another into the receiving space 8 of the bending units, keeping them separated and set at a distance apart in such a way as to bring them up to the receiving space 8 in times that are close to one another but distinct. To illustrate said characteristic, Figure 2 shows four bars B while they are rolling towards the receiving space 8 of the bending units (not visible in Figure 2) in positions appropriately separate and set at a distance apart from one another.
In the example illustrated the angle of inclination of the transverse arms 11 can be controlled by means of a fluid cylinder 12. In particular, it is possible to envisage a raised condition of the arms 11 in order to prevent any sort of interference between the latter and the bars that are bent in the bending units.
In the case of the embodiment illustrated herein, the bars B are fed to the inclined surface Q by means of a longitudinal distribution of chain-driven conveyors 14, each equipped with a number of projecting elements that define separate compartments 14a.
According to one embodiment, the compartments 14a of the feed device defined by the chain-driven conveyors 14 are to be fed each with a single bar by means of the automatic loading device that will be described in detail in what follows.
In Figures 3-12, the conveyor system constituted by the array of chain-driven conveyors 14 is also illustrated schematically. In said figures, the reference number 50 designates a device for automatic picking-up and loading of any predetermined and desired number of metal bars onto the conveyor system constituted by the chain-driven conveyors 14. The device 50 picks up the bars from a bundle of bars B prearranged in a magazine of bars M, which, in the example illustrated, is constituted by a channel-like structure 51 supported by a framework 52 and provided along its bottom with an array of horizontal rollers 53 mounted in a freely rotatable way, which favour feed of the bars B above the magazine M.
The device 50 comprises a fixed supporting structure, which, in the example illustrated, has two end heads 54, which each include a base 55 resting on the floor, a column 56 extending upwards from the base 55, and a cross member set in cantilever fashion 57 projecting from the top of the column 56 in a transverse direction with respect to the longitudinal direction of the magazine M.
It should be noted that in Figures 3-12 the various component parts of the device according to the invention are illustrated only schematically, both in so far as the elimination of the constructional details renders the drawings themselves simpler and more readily understandable and in so far as said constructional details can be provided in any known way, as will be readily understood by persons skilled in the branch.
On the cross members 57 of the end heads 54 two carriage structures 58 are guided, each having at least one motor-driven roller or wheel 59. The two motor-driven wheels 59 are driven between respective mutually aligned shafts 60 extending in a direction parallel to the longitudinal direction L of the magazine M. The two shafts 60 extend from a motor reducer 61, which connects the shafts themselves to an electric driving motor 62, for governing simultaneous displacement of the carriages 58 along the cross member 57 in a direction transverse with respect to the longitudinal direction of the bars B, said transverse direction being designated by the arrows X in the drawings. Any different system of transmission is of course possible; for example, two motors associated, respectively, to the two carriages could be envisaged.
Once again with reference to the specific embodiment illustrated herein purely by way of non-limiting example, suspended from the two carriages 58 is a longitudinal beam 63 that extends parallel to the longitudinal direction of the bars B. The cross member 63 supports, appropriately distributed along its length, a plurality of levers 64 mounted articulated on the beam 63 about a common longitudinal axis 64b and governed each by a respective fluid actuator 65 between an inoperative position (visible in Figure 3), in which the free ends of the levers 64 face vertically downwards, and an operative position (visible, for example, in Figure 10), in which the free ends of the levers 64 extend horizontally in cantilever fashion starting from the beam 63. The free end of each lever 64 carries a freely rotatable roller 64a designed to favour proper engagement of the bars B above the levers 64 when the latter are in the operative position, as will emerge more clearly from the ensuing description.
The beam 63 also carries an endless chain C, which engages on two gears 66 set at the ends of the beam 63 and has two longitudinal branches extending parallel to the longitudinal direction L of the magazine M. One of the two gears 66 is governed by an electric motor (not visible in the drawings), which enables motion to be imparted on the endless chain C. Said chain is used for governing a displacement in the longitudinal direction (designated by the arrows L in the drawings) of the magazine M of a further lever device (see, for example, Figure 9) comprising a lever 68 mounted articulated about a vertical axis on a plate-type support 67 connected to the chain C and governed by means of a fluid actuator 69 between an inoperative position, in which it extends parallel to the original direction L (see, for example, Figure 3), and an operative position, visible in Figure 9, in which it extends in the transverse direction X. Preferably, also the lever 68 carries a freely rotatable roller for proper engagement thereon of the bars B, as will be illustrated in greater detail in what follows.
Moreover associated to one of the carriages 58 (the right one, with reference to Figure 3) is a device for picking up the bars, comprising a magnet 70 set at the bottom end of a vertical stem governed by a fluid actuator 71.
According to a solution already proposed by the present applicant in the patent applications Nos. EP 2 172 287 A1 and EP 1 980 341 A1 , associated to the pick-up device 70, 71 is a limiter device 72 illustrated schematically in Figure 13. Said device is basically constituted by a pair of plates 73 extending in a common plane orthogonal to the longitudinal direction L, said plates being connected rigidly, in the specific case illustrated herein, to the structure of the respective carriage 58. The two plates 73 define between them a vertical passage 74 of a width corresponding to the thickness of the bars B (preferably envisaged is the possibility of regulation of the distance of the plates 73 in order to adjust the width of the passage 74). The passage 74 moreover has a V-shaped lead-in mouth 75. As already illustrated in the patent documents identified above, when the magnet-type pick-up device 70 grips the end of one or more bars B in the bundle inside the magazine M and raises it/them upwards, the bars are forced to set themselves one on top of another to pass through passage 74 so that only the end of one bar reaches a raised position above the passage 74, whilst the others, on account of the insufficient force of attraction of the magnet M drop down, as illustrated schematically in Figure 13. The limiter device 72 basically functions as limiter designed to enable only the end of one bar at a time to reach the raised position above the limiter 72. Even though it is not illustrated in the annexed drawings, it is also possible to envisage a gripper device that blocks temporarily in position the portions of bar that reach the aforesaid raised position.
Even though the example illustrated shows an action of picking up performed by means of raising of the end of a bar into a raised position above the bundle, it would also be possible to envisage an action of picking up performed by gripping the portion of a bar and displacing it into a generic position at a distance from the bundle, even one not raised with respect to the bundle.
In what follows, operation of the device for automatic picking-up and loading of the bars that has been illustrated above will be described.
The pre-arrangement of the carriages 58 enables the magnet 70 for picking up the bars to be brought onto the vertical of the area of the magazine M, where the bars are to be picked up. Said characteristic is important in so far as it always enables bars to be picked up from the magazine M even when the latter is progressively emptying. Of course, it is possible to envisage alternative solutions whereby, during the step for picking up the bars from the magazine, it is not necessary to move the pick-up device in the direction X via the carriages 58. For example, it is possible to envisage that it is the magazine M that displaces along X via displacement means purposely provided therein. Or else, it is possible to envisage that said magazine is defined by mobile walls, which are able to keep the bars B of the bundle always in a grouped position suitable for facilitating picking-up of the bars set on the top of the bundle, for example, causing the bundle always to have a greater height in the central area (with respect to the transverse dimension of the bundle). As an alternative, the magazine can be defined by a structure with fixed walls, shaped, however, in such a way as to provide a cradle effect, to keep the bars grouped together as the magazine empties.
Figure 3 shows the carriages 58 in the inoperative position, at the end set further back of the cross member 57. Starting from said position, the carriages 58 are brought into an advanced position, where the magnet 70 is on the vertical of the bars B set in the magazine M. Starting from said condition, the magnet 70 is lowered (Figure 5) and then raised again so that the end of one or more bars B can be picked up. In the movement upwards of the magnet M, said bars are forced to pass through the limiter 72 (Figure 13) so that just one bar remains attached to the magnet 70 and reaches the raised position visible in Figure 7. In said condition, the lever 68 is brought into its operative position by means of activation of the actuator 69 (more clearly visible in Figure 9), so that the lever 68 moves underneath the raised end of the bar that has been picked up, as illustrated in Figure 7. Starting from said condition, the endless chain C is set in motion so as to displace the lever 68 longitudinally in the direction L and raise the bar B that has been picked up progressively throughout its length. As the lever 68 proceeds from one end to the other of the bar B that has been picked up, the raised part of the bar is kept in said position by gradual activation of the levers 64. Figure 8 shows the device with the lever 68 that has already been displaced for a certain length underneath the bar B that has been picked up, so that one of the levers 64 (the one furthest to the right in the figure) has been brought into the operative position, so as to support the bar B. Figure 9 shows the further displacement of the lever 68, with the consequent raising of the levers 64 set to the right thereof (with reference to the figure), and Figure 10 shows the end of said operation, with the lever device 68 that has reached the opposite end of the beam 63 and all the levers 64 set in their raised operative position, where they keep the bar B that has been picked up in the raised position.
Starting from said condition, the bar that has been picked up and completely separated from the bundle can then be laid in a corresponding compartment 14a of the feed system defined by the chain-driven elevators 14 by means of advance of the carriages 58 and partial rotation of the levers 64, as illustrated in Figure 12. Once the compartment 14a has been reached, the bar B is displaced upwards by the chain-driven device 14 (Figure 2). The operation is repeated in succession for a plurality of bars so that all the compartments 14a are filled with a respective bar B, as illustrated in Figure 2, which enables the bars B to be fed in rapid succession onto the sliding surface Q, from which the bars drop once again in rapid succession, so as to reach in times that are close to one another but distinct the receiving space 8 on the bending units, which guarantees that said bars cannot bestraddle one another in said final step of conveyance into the receiving space 8.
As emerges clearly from the foregoing description, the fundamental characteristic of the device for picking up and loading automatically the bars, as illustrated above, lies in the fact that the operations of picking up, separating, and transferring the bars B from the magazine M up to the operating unit are performed by displacing the bars only in a transverse direction with respect to their longitudinal direction, i.e., without any substantial movement of the bars in their longitudinal direction.
In the present description, and in the ensuing claims, by the expression "without any substantial movement in the longitudinal direction" is meant that the maximum displacement of the bars in the longitudinal direction is considerably less than the length of the bars, i.e., at least less than one half of the length of the bars and preferably is substantially zero.
In the foregoing description, the device for automatic picking-up and loading of the bars has been described with reference to feeding of the bars to a system for bending bars. The device could, however, be used for feeding the bars to any operating unit, for example, also to a bench for cutting bars or any other workstation of a system.
In combination with the characteristic regarding the absence of any substantial displacement of the bars in their longitudinal direction, the example illustrated herein presents the further characteristic of picking up, separating, and transferring only one bar at a time. Said characteristic guarantees proper picking-up and loading of the bars.
The absence of any substantial displacement of the bars in their longitudinal direction enables provision of a system that has a minimum encumbrance in the horizontal plane, specifically in the direction parallel to the longitudinal direction of the bars.
Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary widely with respect to what has been described herein purely by way of example, without thereby departing from the scope of the present invention.
For example, as already mentioned above, the relative movement in the direction X between the pick-up device 70 and the separating means 68, 64 on the one hand, and the bars in the magazine M on the other, can be obtained in a different way, for example, by providing a magazine that is mobile in the direction X. In addition, as also already mentioned, it is also possible to prevent said alternative movement in the case where the magazine is equipped with mobile or cradle-shaped walls, which will enable the bars to be kept grouped appropriately as the magazine is emptying.
The conformation and arrangement of the separator member 68 and of the supporting member 64 can of course also be varied as compared to the one illustrated herein purely by way of example. In particular, it is also possible to adopt actuator means of a different type for governing longitudinal movement of the separator member 68 and the movement of activation of the supporting member 64. Also the conformation and arrangement of the fixed structure 54 and/or of the carriage structures 58 can be devised in a way different from what has been described herein purely by way of example. The same applies to the conformation of the feed device 14 that feeds the bars to the operating unit after receiving them from the device for picking up and separating the bars, the arrangement with chain-driven elevator devices being illustrated herein purely by way of example (for instance, devices with augers or cams, lifters, levers or the like can be used as an alternative).
Picking-up of the bars can be performed by gripping the bars at one end or at the centre, or in any other intermediate position. The separating members can consequently be one or more and can be displaced longitudinally or else be situated in fixed positions in the longitudinal direction and be activated in succession to engage different portions of the bar.
Figures 14-22 illustrate a second embodiment of the device for automatic picking-up and loading of bars described herein. In said figures, the elements in common with the embodiment previously illustrated are designated by the same reference numbers.
Said embodiment differs from the one previously illustrated in that in it the pick-up device 70 is set on the beam 63 in such a way as to grip one or more bars in their central portion. In particular, the pick-up device is set at the centre of the beam 63, together with the limiter device (not illustrated) described previously with reference to Figure 13. The pick-up device 70 has - also in this embodiment - a magnet, but it is clear that, as an alternative, it could also have gripper means or any other pick-up means capable of taking the portion of one or more bars from the bundle of bars in the magazine up to a position at a distance from the bundle of bars.
Moreover, in said second embodiment the means for separating the bars comprise, instead of the single chain C that extends from one end to the other of the beam 63, two endless chains C', each carried by a pair of gears 66 mounted on the beam 63. The two chains C' are set on either side of the pick-up device 70 so as to extend each along one half of the beam 63, from an area in the proximity of the device 70 as far as the end of the corresponding beam. Each chain C' carries with it one or more rollers 68' freely rotatable about their own axis and extending in the direction X. As will be seen in what follows, the rollers 68' perform the function of engaging the bars picked up to raise them progressively along their length and thus separate them from the bundle of bars in the magazine.
Preferably, underneath the pick-up device 70, the beam 63 carries a plate 81 designed to define a contrast surface for the bars that have been picked up.
In what follows, operation of said device for automatic picking-up and loading of the bars will be described.
Starting from the inoperative position illustrated in Figure 14, the carriages 58 are brought as far as the advanced position illustrated in Figure 15, where the magnet 70 is on the vertical of the bars B set in the magazine M. In said condition, the magnet 70 is lowered (Figure 16) and then raised again so as to pick up the central portion of one or more bars B. In the movement upwards of the magnet M, said bars are forced to pass through the limiter device illustrated in Figure 13 so that just one bar remains attached to the magnet 70 and reaches the raised position visible in Figure 17.
In said condition of the bar that has been picked up, the chains C' start to move along their respective closed path: the chain C' illustrated on the left in the figures in a clockwise direction, and the chain C' illustrated on the right in the figures in a counterclockwise direction. During said movement of the chains, the rollers 68' move underneath the central raised portion of the bar that has been picked up, as illustrated in Figure 17, and, starting from said condition, move longitudinally in the direction L, the rollers 68' of the left-hand chain C' towards the left, and the rollers 68' of the right-hand chain C' towards the right, so as to raise progressively the opposite portions of the bar B that has been picked up. At the same time, whilst the bar is engaged by the rollers 68', it leaves the magnet and comes to bear upon the plate 81, which constrains it at the top. As the rollers 68' proceed towards the end of the bar, the raised part of the bar is kept in said position by means of gradual activation of the levers 64 in the same way as what has been described with reference to Figures 3 to 13. Figure 18 shows the two central levers 64 already set in their operative, raised, position, whilst the two outer levers 64 are still in their lowered position, awaiting passage of the roller 68'.
Figures 19 and 20 show picking-up of a second bar B' within the same step of loading by the device, immediately after the first bar B has been picked up and separated from the bundle of bars in the magazine. The magnet 70 picks up the central portion of the bar B'. At that point, the rollers 68' are moved in the direction L, as described above, and come to engage said bar for raising it progressively. During said movement by the rollers 68', the levers 64 are lowered in succession and then raised again to prevent interference with the action of the rollers 68': in particular, each lever 64 moves downwards when the roller 68' directed towards it is still at a given distance, whilst it rises again only after the roller 68' has passed beyond it so as to support both the first bar and the second bar. The distance referred to above between the lever 64 and the roller 68, at which it is envisaged that the lever 64 will move down, must be such that, in the first place, the bar B' that the roller 68' itself is raising, does not interfere with the lever 64 itself, while this is moving down, and, in the second place, the portion of the bar B that up to that moment was supported by the lever 64 comes temporarily to rest on the roller 68' itself until the lever is raised again. This occurs for all the levers 64 until both the first bar and the second bar again find themselves supported by said levers, which are all again in their raised position.
Illustrated in Figures 21 and 22 is the same operation described above for loading of a third bar B".
At this point, as for the device of Figures 3 to 13, the bars B, B' and B'', picked up and completely separated from the bundle, can then be set in a corresponding compartment 14a of the feed system defined by the chain-driven elevators 14.
It should be noted that also the device for automatic picking-up and loading illustrated in Figures 3 to 12 is able to pick up and load a plurality of bars at a time on the transfer means 14. For said purpose, in a modality altogether similar to what has been described with reference to the embodiment illustrated in Figures 4 to 22, from picking-up of the second bar onwards, during movement of the separator member 68 for separating each bar, the levers 64 are lowered and then raised again in succession, in order not to interfere with the action of said member. Once the bars have been picked up in the desired number, they can be laid in a corresponding compartment 14a of the feed system defined by the chain-driven elevators 14 by means of advance of the carriages 58 and partial rotation of the levers 64, in the same way as is illustrated in Figure 12.
In the case where the operating unit is a cutting unit, the structure of the device for automatic picking-up and loading of the bars described herein (for example, in one of the two embodiments illustrated above) could be provided alongside the cutting bench, and the feed device with chain-driven elevators 14 could cause the bars to drop on the bench, where they would subsequently be referenced in position and cut to the desired length. Alternatively, the device could be set alongside a bench aligned longitudinally with respect to the cutting bench, where the bars picked up can be again grouped and then fed longitudinally to the cutting bench, where they could be cut all together.
The system is of course prearranged for being controlled automatically by means of an electronic control unit, according to a technique in itself known, which activates the various component parts of the system in an automatic way, according to any predetermined cycle and on the basis of the setting of the desired number of bars to be fed to the operating unit.
In the case of the example illustrated, the device gets the portion of just one bar at a time to arrive in the raised position above the magazine and consequently envisages separation of just one bar at a time from the bundle and transfer of just one bar at a time to the operating unit. However, handling of just one bar at a time could be left just to any one of said operations. For example, it would be possible to envisage raising the portions of a number of bars together and then separating them one at a time.

Claims

A system for the treatment of metal bars (B), in particular bars for the reinforcement of concrete, of the type comprising:
- at least one operating unit (1), such as, for example, a bending unit or a cutting unit; and

- a device for picking up, separating, and transferring (50) the bars (B), for feeding a plurality of bars (B) to the operating unit (1), picking them up in any desired predetermined number from a bundle of bars (B) deposited in a magazine (M) and separating them from the remaining bars of the bundle,
wherein said device for picking up, separating, and transferring the bars comprises:
- pick-up means (70, 71), designed to bring each time the portion of one or more bars from the bundle of bars (B) in the magazine (M) up to a position at a distance from the bundle of bars (B);

- separating means (68, 64), designed to separate completely said one or more bars (B) from the bundle of bars in the magazine whenever portions of said one or more bars (B) reach said position at a distance from the bundle; and

- transfer means (58, 64, 14), designed to transfer said one or more bars (B) picked up and separated to the operating unit (1),
wherein said pick-up means, said separating means, and said transfer means are provided for displacing the bars (B) up to the aforesaid operating unit (1) by displacing them substantially only in directions (X) transverse to their longitudinal dimension (L), characterised in that said transfer means are designed to feed the bars (B) to said operating unit one after another, keeping them separate and at a distance at least in a final step of conveyance to the operating unit(8) so as to bring them up to the latter in times that are close to one another but distinct.
The system of Claim 1, characterized in that said operating unit (1) is a bending unit defining a plane of bending and a space (8) for receiving a number of bars (B) to be bent set parallel to one another and on top of one another in a plane orthogonal to the bending plane, and
in that said transfer means (58, 64, 14) are designed to feed the bars (B) one after another into said receiving space (8), keeping them separate and at a distance at least in a final step of conveyance into the receiving space (8) so as to bring them up to the receiving space (8) in times that are close to one another but distinct.
The system according to Claim 1 or Claim 2, characterized in that said pick-up means (70, 71) are designed to bring each time a portion of just one bar from the bundle of bars (B) in the magazine (M) up to a position at a distance from the bundle of bars (B), said pick-up means co-operating with limiter means (72), designed to enable only the portion of one bar (B) picked up at a time to reach said position at a distance, and
in that said separating means (68, 64) are designed to separate completely one bar (B) at a time from the bundle of bars in the magazine whenever the portion of a bar (B) reaches said position at a distance from the bundle.
The system according to any one of the preceding claims, characterized in that said pick-up means comprise a magnet-type pick-up device (70) controlled by an actuator (71) and displaceable between a lowered position and a raised position.
The system according to Claim 4, characterized in that said magnet-type pick-up device (70) is carried by a structure (58) mobile in a direction (X) transverse with respect to the longitudinal direction (L) of the bars (B) in the magazine (M).
The system according to any one of the preceding claims, characterized in that the magazine (M) is displaceable in the direction (X) transverse with respect to the longitudinal direction (L) of the bars (B) in the magazine (M).
The system according to any one of the preceding claims, characterized in that said magazine (M) is defined by walls designed to keep the bars (B) grouped together as the magazine (M) is emptied, so as always to offer bars to be picked up properly to the pick-up device.
The system according to Claim 1, characterized in that said separating means comprise:
one or more separating members (68), which can be displaced in the longitudinal direction (L) of the bars; and

a plurality of engaging members (64), which are situated in predetermined positions in the longitudinal direction (L) and can be activated by means of respective actuators (65) for supporting the part already raised and separated of the bar (B) that has been picked up, after passage of said one or more separating members.
The system according to Claim 1, characterized in that said separating means comprise a plurality of separating members, which are situated in predetermined positions in the longitudinal direction (L) and can be raised by means of respective actuators for separating and supporting respective portions of bar.
The system according to Claim 8, or according to Claim 9 when dependent on claim 8, characterized in that said one or more separating members (68), said engaging members (64), and said pick-up means are all carried by a structure (63) that is mobile with respect to a fixed structure (54) in a direction (X) transverse with respect to the longitudinal direction (L) of the bars.
The system according to any one of Claims 8-10, characterized in that said engaging members (64) that support the bar after it has been completely separated from the bundle can be oriented for unloading the bar that has been picked up and separated (B) onto a device (14) for feeding the bar (B) to the operating unit.
The system according to Claim 11, characterized in that said feed device comprises a plurality of chain-driven elevator conveyors (14) that define a plurality of aligned compartments (14a), which are each to receive one or more bars (B) picked up and separated from the bundle of the magazine (M) and to deposit them on an inclined surface (Q) for conveying the bars to the operating unit (1).
The system according to Claim 3, characterized in that said limiter means (72) comprise a structure defining a restricted passage (74) for the portions of bars (B) that have been picked up by said magnet pick-up device (70), so that, in the case where the magnet picks up more than one bar, the bars picked up set themselves on top of one another vertically, so that only the bar in the uppermost position reaches a raised position above said limiter means (72) in so far as the remaining bars drop back down owing to an insufficient force of attraction of the magnet (M).
A method for automatic loading of metal bars (B), in particular bars for the reinforcement of concrete, in a system for treating bars, comprising at least one operating unit (1), such as, for example, a bending unit or a cutting unit,
wherein the bars (B) are fed to the operating unit (1) by being picked up in any desired predetermined number from a bundle of bars (B) deposited in a magazine (M) and by being separated from the remaining bars of the bundle as follows:
- portions of one or more bars (B) from the bundle of bars in the magazine (M) are brought up to a position at a distance from the bundle of bars (B);

- whenever the portions of said one or more bars are picked up and reach said position at a distance from the bundle, said one or more bars (B) are separated completely from the bundle; and

- the bars thus picked up and separated are transferred to the operating unit (1),
wherein said bars are displaced substantially only in directions transverse to their longitudinal dimension in the aforesaid pick-up step, in the aforesaid separation step, and in the aforesaid transfer step,
characterised in that during the transfer step, the bars (B) are fed to the operating unit one after another, keeping them separate and at a distance at least in a final step of conveyance to the operating unit (8) so as to bring them up to the latter in times that are close to one another but distinct.
The method according to Claim 14, characterized in that said operating unit (1) is a bending unit defining a plane of bending and a space (8) for receiving a number of bars to be bent set parallel to one another and on top of one another in a plane orthogonal to the bending plane, and
in that the bars are transferred one after another into said receiving space (8), keeping them separate and at a distance at least in a final step of conveyance into the receiving space, so as to bring them up to the receiving space in times that are close to one another but distinct.
The method according to Claim 14, characterized in that:
- each time a portion of just one bar (B) is brought from the bundle of bars in the magazine (M) up to a position at a distance from the bundle of bars (B), limiter means (72) being provided, designed to enable just one bar (B) at a time to reach said position set at a distance,

- whenever the portion of a single bar is picked up and reaches said position at a distance from the bundle, the single bar (B) is separated completely from the bundle, and

- the bars thus picked up and separated are transferred to the operating unit (1).
The method according to Claim 14, characterized in that the portion of one bar at a time is brought into said position at a distance from the bundle of bars in the magazine (M), the bar being gripped in a position adjacent to one end thereof or at its centre, and in that
when said portion of the bar has reached said position at a distance from the bundle of bars in the magazine (M) one or more separating members (68) are activated, which displace along the bar that has been picked up so as to separate it completely from the bundle of bars in the magazine (M), and in that
as said one or more separating members (68) move along the bar (B) that has been picked up, further engagement members (64) for engaging the bar to support the bar in the aforesaid position at a distance from the bundle of bars in the magazine (M) are activated after passage of said one or more separating members.
The method according to Claim 14, characterized in that the portion of one bar at a time is brought into said position at a distance from the bundle of bars in the magazine (M), the bar being gripped in a position adjacent to one end thereof or at its centre,
when said portion of the bar has reached said position at a distance from the bundle of bars in the magazine (M), a number of separating members situated in predetermined positions in the longitudinal direction (L) are activated, being raised by means of respective actuators for separating and supporting respective portions of bar.
The method according to Claim 17 or Claim 18, characterized in that said members (64) that support the bar after it has been completely separated from the bundle are oriented for unloading the bar that has been picked up and separated (B) onto a device (14) for feeding the bar (B) to the operating unit.