EP2878397B1

EP2878397B1 - A process and plant for ordering a set of metal bars of different lengths

Info

Publication number: EP2878397B1
Application number: EP14191797.1A
Authority: EP
Inventors: Stefano Peruzzo
Original assignee: Oscam Srl
Current assignee: Oscam Srl
Priority date: 2013-11-05
Filing date: 2014-11-05
Publication date: 2021-01-06
Anticipated expiration: 2034-11-05
Also published as: EP2878397A1; ITTO20130898A1

Description

The present invention relates to a process for ordering a set of metal bars of different lengths, arranged all together in a first storage area, within a second storage area provided with a plurality of compartments. In particular, the process according to the present invention envisages dividing the bars between the aforesaid compartments according to their length. EP2377631A2 is part of the technical background. Known from this document are a method and a plant for ordering a set of metal bars of different lengths. The individual bars are fed a predetermined length through a reference point and then cut.
The process in question aims principally at solving the problem of management of bundles of bars constituted by bars of lengths that are very different from one another, starting, for example, from four metres or six metres, up to twelve metres. Bundles of bars of this sort are commonly marketed by steel manufacturers, or by steel-transformation centres, at much more contained prices by virtue of the marked inhomogeneity of the lengths of the bars. The bars of the aforesaid bundles constitute the residue of steel-rolling processes.
So far, however, management of bundles of this sort is rather problematical. The automatic plants currently in use in the art, such as for example cutting plants, are in fact prearranged for treating only bundles of bars of standard length or in any case of one and the same length. Use thereof for bundles of the type in question, constituted by bars of lengths that are very different from one another, is extremely inefficient and entails generation of a very large amount of waste material. For example, a cutting plant programmed for cutting bars to 6 m, using at the same time bars of both 12 m and 8 or 9 m in length will per bar, respectively.
There is hence evident the need, in order to be able use the bundles of bars in question efficiently and without any waste, to order the bars, first, according to length.
The object of the process according to the invention is to achieve precisely this purpose, via the characteristics specified in the ensuing claims.
The claims form an integral part of the technical teaching provided herein in relation to the invention.
Further characteristics and advantages of the invention will emerge clearly from the ensuing description with reference to the annexed drawings, which are provided purely by way of non-limiting example and in which:

Figure 1 is a schematic illustration of two variant embodiments of the process described herein;
Figure 2 is a perspective view from beneath of the device for picking up and feeding bars provided in one embodiment of the plant described herein;
Figure 3 is a perspective view of the pickup assembly with magnet, forming part of the device of Figure 2;
Figure 4 is a perspective view of the assembly for transfer of the bars by means of pincers, which forms part of the device of Figure 2;
Figure 5 is a perspective view of the roller-type feed assembly, which forms part of the device of Figure 2;
Figures 6A-6G are perspective views that show in succession the various operating steps of the pickup-and-feed device of Figure 2;
Figure 7 is a schematic perspective view of one end of the cutting bench provided in one embodiment of the plant described herein;
Figures 8A-8I illustrate the devices of the cutting bench of Figure 7 in different operating conditions, where some details of Figure 7 have been further simplified, for reasons of greater clarity of illustration;
Figure 9 is a perspective view at an enlarged scale of a detail of a device of the cutting bench of Figure 7;
Figure 10 is a simplified side view of the cutting bench in one embodiment of the plant described herein;
Figure 11 is a front view of an embodiment of the unloading means of the plant described herein;
Figures 12A and 12B illustrate in the form of tables examples of correspondences used in the process described herein;
Figure 13 illustrates an embodiment of the first storage area of the plant described herein; and
Figures 14A and 14B are, respectively, a perspective view and a side view of a further example of the unloading means described herein.

Illustrated in the ensuing description are various specific details aimed at providing an in-depth understanding of the embodiments. The embodiments may be provided without one or more of the specific details, or with other methods, components, or materials, etc. In other cases, known structures, materials, or operations are not shown or described in detail so that various aspects of the embodiments will not be obscured.
The references used herein are provided only for convenience and hence do not define the sphere of protection or the scope of the embodiments.
As schematically represented in Figure 1, the process described herein has the purpose of ordering a set of metal bars B of different lengths, arranged in bundles in a first storage area S1, within a second storage area S2 (or S2') provided with a plurality of compartments, dividing the bars according to length between the different compartments.
In general, the process in question comprises the steps of:

picking up the bars from the bundle in the first storage area (step A of Figure 1); and
transferring the bars from the first storage area to the second storage area, in which the aforesaid transfer envisages at least one step in which the bars are fed in a direction parallel to or coinciding with their longitudinal direction (step B1 or B2 of Figure 1) .

The process in question is characterized in that the aforesaid feed step is exploited for measuring indirectly the length of the individual bars, and then the individual bars are treated differently according to the length measured, the purpose being as will be seen, to order them in a pre-set way.
The aforesaid measurement of the length of the bars is performed using one or more sensors 101 designed to detect passage of the individual bars in a reference point P of the plant during the aforesaid feed from the first storage area to the second storage area. The process then envisages determination of the length of feed or time of feed of the individual bars with respect to the reference point of the plant on the basis of the data coming from the aforesaid sensors. It is to be noted now that the length of feed and time of feed of the individual bars thus determined evidently constitute an indication, respectively a direct one and an indirect one, of the value of length of the bars. The feed considered is in fact limited to the step in which the individual bar passes with its longitudinal extension through the reference point in question, i.e., in which the aforesaid sensor detects passage of the bar in the aforesaid point while the bar is advances in its longitudinal direction.
The aforesaid sensors may be a presence or proximity sensor or else a movement sensor, associated to the reference point P of the plant and designed to detect the presence or the movement of the individual bars at the aforesaid reference point. The sensors in question may be of any type, for example, optical, electromechanical, magnetic, etc. In the example illustrated in Figure 1, the sensor 101 is an optical sensor set at the reference point P and designed to recognize the passage of the bars underneath.
After determining the aforesaid quantities, the process envisages treating the individual bars in a pre-set way as a function of the value determined.
In particular, as represented schematically in Figure 1, the process envisages either unloading the individual bars into a respective compartment of the second storage area that is selected on the basis of the value of a given length (see in this connection step B1 of the process illustrated), or else first cutting the individual bars to a pre-set length, which is a function of the aforesaid value, and then unloading the bars that have been cut into a respective compartment that is selected on the basis of the aforesaid pre-set length or else of the value of a given length (see in this connection steps B2 and B2' of the process illustrated).
In the first embodiment without the cutting step, the process may envisage use of correspondences (schematically represented in Figure 12A) between the series of compartments of the second storage area (C1, C2, ..., Ci) and a series of ranges of values of length of the bars (X1-X2, X2-X3,..., Xi-Xi+1), which extends between end values such that a respective interval can be associated to all the bars of the bundle on the basis of the length measured.
In the second embodiment, which comprises also the cutting step, the process may instead envisage the use of triple correspondences (schematically represented in Figure 12B) between the series of the compartments of the second storage area (C1, C2, ..., Ci), a series of pre-set lengths (X1', X2', ..., Xi'), and a series of ranges of values of length of the bars (X1-X2, X2-X3,..., Xi-Xi+1), which also in this case extends between end values such that a respective interval can be associated to all the bars of the bundle on the basis of the length measured.
It is to be noted that by the terms "pre-set length" or "value of length" is in general to be understood any quantitative indication that is an either direct or indirect expression of the length of the bars.
On the basis of the aforesaid correspondences, the process in question hence envisages either direct ordering of the individual bars measured in the various compartments Cx of the second storage area that are assigned to them according to the length measured Xn (Figure 12A) or else first cutting of the individual bars to the pre-set length X'i assigned to them according to the length measured Xn, and then ordering of the bars cut in the various compartments Cx likewise assigned according to the length measured Xn (Figure 12B). It is evident that in the former case, there will be unloaded into each compartment of the second storage area bars of possibly different lengths but comprised within a given range of values, whereas in the latter case there will be unloaded therein bars that are all substantially of one and the same length.
With reference now to Figure 1 and to Figure 12A, it may be noted, for example, that in the first embodiment, assigned to the compartment C1 is the range of values X1-X2 (for example, 4 - 5), and consequently the bars whose value of length determined falls within the aforesaid range of values (i.e., in the example, bars having a length of between 4 m and 5 m) will be unloaded therein. With reference to Figure 1 and to Figure 12B, in the second embodiment, assigned instead to the compartment C1 is a pre-set value X1' (for example 5) to which there is in turn assigned a range of values X1-X2 (for example 5 - 6); consequently, in this case, the bars whose value of length determined falls within the aforesaid range (i.e., in the example, bars whose length is comprised between 5 m and 6 m) will be first cut to the pre-set length X1' (in the example, 5 m), and will then be unloaded into the compartment C1. In the first embodiment, the process may in any case possibly envisage also a cutting step for reducing the bars to a pre-set length, where there is, for example, the immediate need for a specific type of bars.
In preferred embodiments, the process described herein envisages also a step of counting of the bars, prior to or simultaneously with the unloading step, in order to know the number of bars unloaded in each compartment of the second storage area. In what follows, some examples of a plant for implementing the process presented above will be described.
In general, the plant in question is a plant of an automatic type, comprising:

means for picking up the bars from the first storage area;
means for transferring the bars picked up from the first storage area to the second storage area, which comprise movement means configured for feeding the bars in a direction parallel to or coinciding with their longitudinal direction;
one or more sensors configured for detecting passage of the individual bars through a respective reference point of the plant;
optionally, means for cutting the bars; and
means for unloading the bars that have been transferred, and optionally cut, into a compartment of the second storage area.

The plant further comprises a control unit 100, represented schematically in Figure 1, programmed for governing the aforesaid means in an appropriate mode for executing the process referred to above. In particular, as will be seen in detail in what follows, the control unit is configured for determining the length of feed or time of feed of the individual bars with respect to the aforesaid reference point, on the basis of the data coming from the aforesaid sensor, and for governing the unloading means and possibly the cutting means as a function of the values determined. In particular, the control unit is configured for enabling setting and/or modification of the correspondences referred to above (and of which two examples are illustrated in Figures 12A and 12B), and, on the basis of these, governing the aforesaid means.
In what follows, different types of the means referred to above will be now illustrated.
In particular, Figures 2 to 6A-6G illustrate a first specific embodiment of the pickup-and-transfer means of the plant.
In the aforesaid embodiment, the means in question are formed by a device 300, designed to pick up the individual bars of the bundle automatically from the first storage area and supply them longitudinally in succession, one after another, and by a roller track 400 (Figure 6G), which transfers the bars fed by the device 300 up to the second storage area.
The device 300 is illustrated as a whole in Figure 2. It has a supporting framework 25, which is in turn supported at one end of a stationary structure.
Figures 3, 4, and 5 show separately three assemblies forming part of the device 300.
With reference to Figure 3, the number 26 designates as a whole an assembly for picking up the bars by means of a magnet, comprising a permanent magnet 27 supported in an oscillating way about a horizontal axis underneath a supporting block (not visible in the drawing), which is in turn slidably guided horizontally within a supporting element 28. This enables the magnet 27, when it picks up a portion of bar B and lifts it, to tilt according to the inclination assumed by an end portion of the bar (see Figure 6B) and at the same time to recede with respect to the block 28 as a result of the resistance opposed by the bar B. The block 28 is set at the end of a stem 29 (see Figure 6A) of a fluid actuator 30, the top end of which is anchored to the cross member of a portal structure 31 secured to the framework of the device (see Figure 3). It is to be noted that instead of the permanent magnet 27 it is possible to provide an electromagnet.
Figure 4 is a perspective view of an assembly for handling the bars B, comprising a pincer-type gripping device 32, which is electrically controlled and is carried by a slide 33 slidably mounted vertically on guides 34. The vertical movement of the slide 33 is driven by a motor 35 by means of an external-screw/internal-screw transmission. The guides 34 and the motor 35 are carried by a structure 36, which is in turn mounted like a slide in a horizontal direction transverse to the longitudinal direction of the bars, on guides 37 carried by a plate 38 secured to the stationary structure of the device. The horizontal movement of the slide 36 on the guides 37 is controlled by a fluid actuator 39.
Figure 5 is a perspective view of an assembly for longitudinal feed of the bars, using a roller-type feed device. The aforesaid assembly, designated as a whole by the reference number 40, comprises a stationary supporting structure 41, mounted on which are rotatable motor-driven bottom rollers 42A, 42B, 42C, which are driven, through a chain transmission 43, by an electric motor 54 (see Figure 6A). The bars are to be received one at a time on the motor-driven bottom rollers 42 and to be contained in the aforesaid arrangement between the sides 44 of a channel 45, the end wall of which is interrupted to enable the bottom rollers 42A, 42B, 42C to project above it. The bars that each time are located in the channel 45 are to be pressed against the motor-driven bottom rollers 42A, 42B, 42C by three top rollers 46A, 46B, 46C supported in a freely rotatable way on two slides 47, which are slidably mounted vertically on the stationary structure 41 and are controlled by fluid actuators 48.
Once again with reference to the magnet pickup device 26, this has a selector element 49 (see Figure 6B) defining a restricted passage 50, preceded by a V-shaped entry mouth 51, through which the bars lifted by the magnet 27 must pass. The restricted passage 50 forces the bars that are picked up by the magnet to assume an arrangement where they are set on top of one another in a vertical plane in way such that the magnet lifting device is able to bring only one bar at a time up to the pre-set raised position.
The device 300 referred to above operates as described in what follows.
With reference to Figure 6A, the magnet 27 of the pickup assembly 26 is lowered until it engages one or more bars B (in Figure 6A just one bar is illustrated for reasons of clarity), which are present in the magazine M of the first storage area (illustrated only schematically in Figure 6A). The magnet 27 is then lifted, carrying one or more bars B along with it up to the restricted passage 50. The presence of the aforesaid passage means that just one bar manages to remain attached to the magnet 27 after this has passed beyond the position corresponding to the restricted passage 50. As may be seen in Figure 6B, the single bar B that has remained attached to the magnet 27 (which in the mean time has assumed its retracted and inclined position) reaches a first raised position, which is represented precisely in Figure 6B. When the portion of the bar B that is carried by the magnet reaches the aforesaid first raised position (Figure 6B), the pincer 32 of the gripping assembly is already in a lowered position, suitable for gripping another portion of the same bar B. The pincer 32 is in particular driven into the aforesaid lowered position by the electronic control means of the plant, which receive instructions for the controlled positions of the pincer, which depend upon the diameter and length of the various types of bars that are handled. In the example of embodiment illustrated, associated to the pincer are the sensor means for issuing a signal to the electronic control unit of the plant whenever it receives a bar therein. In this way, the system is able to count the bars picked up, as they reach the pincer, so as to verify that any pre-selected number of bars is fed. Of course, however, the means for counting the bars picked up could even be altogether different and provided in other points of the plant. It is to be noted that, in the case of use of an electromagnet, as soon as the sensor means associated to the pincer detect the presence of a bar, the magnet is de-energized in order to release the aforesaid bar to the pincer 32. In the embodiment with the permanent magnet 27, it is, instead, the pincer 32 that removes the bar therefrom.
As may be seen in Figure 6C, the pincer 32 is then displaced transversely until it carries the bar B above the channel 45 so as to be able to unload it onto the channel 45. Figure 6D shows the step in which the pincer 32 has opened and the bar B is being dropped onto the channel 45 and onto the motor-driven bottom rollers 42A, 42B, 42C. At this point, the top rollers 46A, 46B, 46C are lowered for pressing the bar B, or rather the portion of bar, that has been previously gripped by the magnet 27, on the motor-driven bottom rollers 42A, 42B, 42C. The ensemble of the aforesaid rollers is thus able to feed the end portion of the bar B previously gripped longitudinally forwards, in the direction X illustrated in Figure 6F, so as to separate the bar B completely from the bundle in the magazine M and feed it downstream of the plant towards the second storage area. As may also be seen in Figure 6F, during the aforesaid step (or even sooner, for example as soon as the magnet releases the bar to the pincer 32), the magnet 27 returns in the mean time into its lowered position for picking up an end portion of a new bar B from the magazine M. As may then be seen, the magnet 27 is displaced alternately between its lowered position and its raised position, whenever the plant has to operate so as to order a pre-set number of bars in the second storage area.
The device 300 comprises the sensor 101 mentioned above, which is designed to detect passage of the bars. In particular, in the aforesaid embodiment, the sensor 101 (which is, for example, a pressure sensor) is associated to the roller 46C of the feed assembly 40 (see Figure 6A), opposed to the motor-driven roller 42C, and is configured for detecting raising and lowering of the first roller with respect to the second upon entry of each individual bar between the aforesaid rollers and after the bar has passed, respectively.
Specifically, with reference to Figures 6E to 6G, when, following upon actuation of the entire assembly, the downstream end of the individual bar arrives between the two rollers 42C and 46C, the sensor 101 detects raising of the latter, then signalling to the control unit the presence between them of the bar, whereas, after the entire bar has traversed the two rollers and also the upstream end of the bar has passed beyond them (Figure 6G), it detects lowering of the roller 46C, signalling to the control unit completion of passage of the bar.
In order to determine the length of the bar, the control unit is programmed for measuring the time of passage of the individual bar with respect to the roller 46C, using the indications coming from the sensor 101, and then combining the aforesaid time value with one or more operating parameters of the roller-type feed assembly, for example the speed of rotation of the rollers 42A, 42B, 42C, so as to determine the length of feed of the bar with respect to the roller 46C and hence the length of the bar. Otherwise, the control unit may be programmed for using directly the time detected as value indicating precisely the length of feed of the bar and hence the length of the bar itself.
In alternative embodiments, also a movement sensor may instead be associated to the roller 46C, for example an encoder, designed to measure the number of rotations of the roller 46C. In this case, the control unit of the plant, by combining the indications coming from the sensor 101 and the data coming from the encoder, is able to determine the number of rotations of the roller 46C during passage of the bar and hence derive the value of length of feed thereof and the length of the bar.
The individual bars picked up and measured are then transferred via the roller track 400 up to the second storage area, where they are then ordered in the respective compartments.
In this connection, the control unit 100 of the plant is programmed with the correspondences described above (see in particular the correspondences of Figure 12A) and, on the basis of the aforesaid correspondences, assigns to the individual bars the respective compartments within which they will be ordered.
The control unit hence governs the unloading means of the plant for unloading the bars into the aforesaid compartments.
A specific embodiment of the unloading means in question will be described in what follows.
Figures 7 to 10 illustrate a different embodiment of the pickup-and-transfer means of the plant.
The aforesaid means are formed by a cutting bench 500 having a mouth 7 designed to receive the front ends of the bars to be supplied on the cutting bench, and shears 510 for cutting the bars (visible in Figure 10).
In order to provide automatic loading of the bars B into the mouth 7, the cutting bench comprises a magnetic lifting device, designated as a whole by the reference number 8. The device 8 comprises an electromagnet 9 carried at the bottom end of an arm 10, in turn carried by a slide 6 that can be displaced vertically with respect to a supporting structure 11 fixed to the structure 2 of the cutting head and is driven by an actuator 12 of any type, for example a pneumatic actuator. In the example illustrated, the slide 6 is joined to two cylindrical guide columns 6a slidably mounted with respect to the fixed supporting structure 11. It is to be noted that instead of the electromagnet 9 it is possible to provide a permanent magnet, as in the embodiment described previously.
The electromagnet 9 is displaceable between a lowered position (Figure 8A), in which it is able to pick up bars B from the first storage area, and a raised position (Figure 8C), in which the front ends of the bars B that have been lifted magnetically by the electromagnet 9 are brought into a raised workstation 13 for receiving the bars. The aforesaid front portions of the bars B that are lifted by the electromagnet 9 encounter along their path towards the raised workstation 13 a restricted passage 14 of a width substantially corresponding to or slightly greater than the diameter of the bars B. Consequently, the bars B that remain attached to the electromagnet 9 are forced to assume an arrangement where they are vertically aligned with respect to one another, one after the other, so that they can pass through the restricted passage 14. On the other hand, the force of the electromagnet 9 is adjusted in such a way that, in the aforesaid condition, only the bar that adheres directly to the magnet remains attached thereto until it reaches the workstation 13, whereas the other bars drop down (Figure 8C), on account of the insufficient magnetic field generated by the electromagnet. In this way, just one bar B manages to follow the electromagnet 9 with its front portion up to the raised workstation 13. Consequently, the aforesaid electromagnet is prearranged and/or adjusted so as to adapt the force of magnetic attraction thereof, also as a function of the weight of the bars to be treated in order to guarantee that the electromagnet is able to bring into the raised receiving workstation 13 only the bar B that traverses the restricted passage 14, remaining in direct contact with the electromagnet. In a position adjacent to the restricted passage 14, the structure of the cutting head carries a pusher member 15 (Figure 9), which can be activated by means of an actuator 16, for example of a pneumatic type, for pushing in a horizontal direction the portion of bar that reaches the workstation 13 on a resting surface 17 defined by a support 18. Figure 9 illustrates at an enlarged scale the detail of the device in which the restricted passage 14 is defined. As may be seen, the aforesaid passage is defined between the facing edges 14a, 14b of two vertical plates 19, 20 substantially coplanar with respect to one another. The edges 14a, 14b define a V-shaped entry mouth 21, radiused with the restricted passage 14. The plate 20 is rigidly connected to the fixed support 18, whereas the plate 19 can be displaced into a horizontal position to adjust the width of the restricted passage 14. For this purpose, the plate 19 is connected to the mobile part of an actuator 22, for example of a pneumatic type, supported by a bracket 23 fixed to the structure of the head 2. The plate 19 also carries the actuator 16 for driving the pusher member 15. As may be seen clearly in Figure 8D, whenever a bar arrives in the raised position corresponding to the receiving workstation 13, the pusher member 15 is activated for separating the bar B from the electromagnet 9 and laying it on the support 18. Once the bar is located on the support 18, a transfer device 24 is activated. In the example illustrated, the transfer device 24 is a pincer transfer device, comprising a pincer-type gripping member, which comprises a top jaw 24A and a bottom jaw 24B, which can be displaced with respect to one another, by means of an actuator 61 (for example, of a pneumatic type) between a closed, clamping, position and an open position. The pincer member is carried at the bottom end of a vertically mobile slide 62, via an actuator 63, for example of a pneumatic type, with respect to a carriage 64, which is in turn mobile horizontally, via an actuator 65, which is also, for example, of a pneumatic type, with respect to a fixed guide structure 66. The actuator 12 for governing vertical displacement of the electromagnet 9, the electromagnet 9 itself, the actuator 16 of the pusher member 15, the actuator 22 of the device for adjusting the width of the restricted passage 14, the actuators 63, 65 of the slides 62, 64 carrying the pincer device 24, and the actuator 61 of the pincer device 24 are all controlled by the control unit of the plant, according to a pre-determined and programmable cycle. In particular, as may be seen in Figures 8F-8I, the pincer device 24 is displaced vertically and horizontally whenever a bar B is located on the support 18 for bringing it up to the mouth 7 so as to enable feed thereof onto the cutting bench.
With reference to Figure 10, the cutting bench 500 has two feed assemblies, arranged respectively upstream and downstream of the shears 510. The first, designated by the reference number 600, is a feed assembly with opposed rollers similar to the feed assembly 40 described with reference to Figures 2 to 6A-6G. The second feed assembly, downstream of the shears, is constituted, instead, by a motor-driven roller track 700 and by one or more pressure rollers 710 that are arranged above the aforesaid track and cooperate with this for moving the bars.
In a way similar to the configuration of the embodiment illustrated previously, the sensor 101 for detecting the passage of the bars is associated to the roller 610 illustrated in Figure 10, of the feed assembly 600. During advance of the individual bars, the sensor 101 detects passage thereof, and the control unit of the plant then determines their lengths, with the same modalities described above with reference to the previous embodiment.
On the basis of the lengths determined, the control unit of the plant is then programmed for governing the various means of the plant so as first to cut the bars that have been measured and then to order them in respective compartments of the second storage area.
In this connection, the control unit is programmed with the correspondences described above (see in particular the correspondences illustrated in Figure 12B), and, on the basis of the aforesaid correspondences, assigns to the individual bars the pre-set lengths to which they are to be cut, as well as the respective compartments within which they will subsequently be ordered.
The control unit then governs the operations of cutting and unloading accordingly. With particular reference to the cutting operation, this envisages that the bar that has already been measured, which is by now located on the roller track 700, will be made to recede from the track underneath the shears 510 up to a position such that, via the cutting operation, the bar will be reduced to the pre-set length assigned to it. Obviously, recession of the bar before cutting will not be necessary in plants in which the sensor 101 is located further away from the shears, as for example in the example illustrated in Figure 1.
After the cutting operation, the control unit again drives the track to carry the bar up to the second storage area, and finally governs the unloading means of the plant for unloading the bar into the compartment assigned.
In various embodiments, the plant comprises counter means. In preferred embodiments, the counter means are designed to detect the individual bars treated by the plant, either when they are picked up from the bundle of the first storage area or else when they are transferred to the second storage area. In even more preferred embodiments, the aforesaid means are represented by the sensor 101 itself.
In order to be able to indicate the number of bars unloaded into each compartment Ci of the storage area S2, in various embodiments the control unit is configured for storing for each compartment a number, initially equal to zero, which identifies the number of bars unloaded therein, and updating it whenever a new bar is associated to the aforesaid compartment.
In the embodiments illustrated above, the rollers 610 and 46C to which the sensor 101 is associated are both located in a position that is downstream of the initial position assumed by the individual bars in the feed assembly before they are fed in their longitudinal direction. As has been seen, this enables the sensor 101 to detect passage of the entire bar so that the value of length of feed finally determined corresponds to the length of the bar.
In any case, the sensor in question does not necessarily need to be associated to a reference point of the plant that is located downstream of the position of start of feed of the bars.
In fact, in general, the aforesaid reference point can also identify a position that is located, instead, precisely in the aforesaid initial position, provided that this is the same for all the bars. In particular, the reference point in question may be identified as exactly corresponding to the downstream end of the individual bars, or else between their downstream end and their upstream end, shifted from the downstream end towards the upstream end - obviously with reference to the movement of feed of the bars - by a distance that is the same for all the bars to be supplied with the assembly in question. In this way, in the latter case, the sensor associated to the reference point so positioned, even though it may not detect passage of the bars throughout their extension, it is in any case able to detect passage of their different portions that are located upstream of the aforesaid reference point, the length of which, added to the aforesaid distance, finally enables, even so, determination of the entire length of the bars.
As has been said, in such an embodiment it is obviously necessary for the aforesaid initial position to be the same for all the bars. For this purpose, the plant can envisage different types of reference members for ensuring that the downstream end of the individual bars will be positioned each time in the same point, i.e., in line with what has been said previously, either with their downstream end exactly at the reference point P to which the sensor 101 is associated or else at the aforesaid pre-set distance from the reference point P.
In particular, in various embodiments, as in the one illustrated in Figure 13, the plant may envisage, in the first storage area S1, a roller track 70 on which the bundle of bars to be ordered is set, which is delimited by a referencing plate 71 at the end, from which the pickup means of the plant will pick up the individual bars from the bundle. The aforesaid track is driven so as to bring the ends of the bars up against the referencing plate and keep them there so that they are referenced precisely in position within the storage area. On the basis of the aforesaid reference position, by simply operating each time according to one and the same predetermined modality, the pickup means of the plant can pick up the individual bars from the track and release them to the feed means always in the same initial position with respect to the reference point P, i.e., in the example illustrated, with their downstream end at the distance d from the aforesaid point.
With reference now to Figure 11, this represents a specific embodiment of the unloading means of the plant.
As may be seen in the above figure, the second storage area S1 extends on both opposite sides of the roller track with which the bars in the two embodiments illustrated above are transferred into the aforesaid area (the track 400 in the embodiment of Figures 2 to 6, and the track 700 of the embodiment of Figures 7 to 10). The area S2 comprises, on each side of the track, a plurality of compartments C1, C2,..., Ci oriented so as to arrange the bars parallel to the track and set in succession in a direction transverse thereto. The compartments are delimited at the top by pivoting supports 800 arranged at heights that differ from one compartment to another, which are mobile between a lowered condition, in which they define a single inclined plane for rolling of the bars by gravity along the series of compartments, above these, and a raised position, in which the supports render the inside of their respective compartment accessible. Associated to the roller track are further supports 900 that can be tipped over to either of the opposite sides of the track in order to dump the bars into one of the two series of compartments.
In operation, the control unit is programmed for controlling, according to the compartments to which the bars are assigned, tipping-over in a given direction of the supports of the roller track and concomitant raising of the respective top supports of the aforesaid compartments, or else just tipping-over of the supports of the track in the case where the bars are to go end up one of the two end compartments.
In the light of the foregoing, it is clear that in the plant described herein the total number of compartments depends upon the division of the bars that is envisaged. For instance, in applications with bundles of bars comprising bars from 4 to 12 m in length, eight compartments will be necessary to divide the bars according to consecutive intervals of length each having a width of one metre.
Finally, Figures 14A and 14B illustrate an embodiment of the unloading means alternative to the one illustrated in Figure 11. In this case, the roller track 400, 700, with supports 900 that can be tipped over, is associated to a carriage 950 on which the compartments Ci of the second storage area are provided and which is mobile underneath the track between two end positions such as to enable tipping of the bars on the track into each of the compartments of the carriage. Alternative embodiments may further envisage that the track 400 or 700 is instead carried by an overhead-travelling-crane structure overlying a fixed structure on which the second storage area is provided.
Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary, even significantly, with respect to what has been illustrated herein purely by way of non-limiting example, without thereby departing from the scope of the invention, as defined by the annexed claims.

Claims

A process for ordering a set of metal bars of different lengths, arranged all together in a first storage area (S1), within a second storage area (S2; S2') provided with a series of compartments (C1, C2, ..., Ci), according to a division by length between the various compartments of said second storage area,
said process being provided via a plant for handling metal bars and comprising the steps of:
- picking up said bars in said first storage area;

- transferring said bars from said first storage area to said second storage area, wherein said transfer step envisages feeding said bars in a direction parallel to or coinciding with the longitudinal direction of said bars;

- detecting, via one or more sensors (101), passage of the individual bars in a reference point (P) of said plant, said reference point being positioned in said plant downstream of the initial position of said individual bars in said movement of feed so that the individual bars will pass through said reference point with all their length, or else said reference point (P) being positioned in said plant at the downstream end of each of said individual bars in said initial position, said initial position being the same for all of said individual bars, so that the individual bars will pass through said reference point will all their length, or again, said reference point being displaced with respect to the downstream end of each of said individual bars in said initial position, towards their upstream end, by one and the same distance, which is the same for all of said individual bars, so that the individual bars will pass through said reference point with their portions that are located upstream of said reference point; and

- determining the respective length of feed or time of feed of said individual bars with respect to said reference point on the basis of the data coming from said one or more sensors,
wherein, optionally, after determining said length of feed or time of feed of said individual bars with respect to said reference point, said process envisages a cutting step, in which the individual bars are reduced to a pre-set length, which is a function of said determined length of feed or time of feed,
said process further comprising the step of:
- unloading said bars, optionally cut, into a respective compartment of said series (C1, C2, ..., Ci), selected on the basis of the determined length of feed or time of feed or of said pre-set length.
The process according to Claim 1, which envisages the use of correspondences between the series of compartments of the second storage area (C1, C2, ..., Ci) and a series of ranges of values of length of the bars (X1-X2, X2-X3,..., Xi-Xi+1), and wherein after said length of feed or said time of feed has been determined, on the basis of said correspondences respective compartments of said series are assigned to the individual bars.
The process according to Claim 1, which envisages the use of triple correspondences between the series of the compartments of the second storage area (C1, C2, ..., Ci), a series of pre-set lengths to be cut (X1', X2', ..., Xi'), and a corresponding series of ranges of values of length of the bars (X1-X2, X2-X3,..., Xi-Xi+1), and wherein after said length of feed or said time of feed has been determined, on the basis of said correspondences respective values of pre-set lengths to be cut and respective compartments of said series are assigned to the individual bars.
The process according to any one of the preceding claims, wherein said pickup and transfer steps envisage picking up and transferring one bar at a time in succession.
The process according to any one of the preceding claims, which envisages counting the bars that are unloaded into each of said compartments.
The process according to any one of the preceding claims, which envisages, before said bars are picked up, a step in which corresponding ends of said bars are substantially aligned to one another.
The process according to any one of the preceding claims, wherein said detection step envisages:
- detecting via one or more sensors (101) passage of the individual bars in a reference point (P) of said plant, so that, during said movement of feed, through said reference point there passes the entire portion of said individual bars that is initially located upstream of said reference point.
A plant for ordering a set of metal bars of different lengths, arranged all together in a first storage area (S1), within a second storage area (S2; S2') provided with a series of compartments (C1, C2, ..., Ci), according to a division by length between the various compartments of said second storage area, said plant comprising:
- means (26; 8) for picking up said bars in said first storage area;

- means for transferring (40, 400; 600, 700) the bars that have been picked up from said first storage area to said second storage area, wherein said transfer means comprise means for feeding said bars in a direction parallel to or coinciding with their longitudinal direction;

- optionally, means (510) for cutting said bars;

- means (800, 900) for unloading said bars that have been transferred, and optionally cut, into a compartment of said series;

- one or more sensors (101) configured for detecting passage of the individual bars in a respective reference point (P) of said plant, said reference point being positioned in said plant downstream of the initial position of said individual bars in said movement of feed so that the individual bars will pass through said reference point with all their length, or else said reference point being position in said plant at the downstream end of each of said individual bars in said initial position, said initial position being the same for all the bars, so that the individual bars will pass through said reference point will all their length, or again, said reference point displaced with respect to the downstream end of each of said individual bars in said initial position, towards their upstream end, by one and the same distance, which is the same for all of said individual bars, so that the individual bars will pass through said reference point with their portions that are located upstream of said reference point; and

- control means (100) configured for determining the respective length of feed or time of feed of said individual bars with respect to said reference point on the basis of the data supplied by said one or more sensors, and wherein said control means are moreover configured for controlling:
i) optionally, said cutting means (510) for reducing the length of the individual bars to a pre-set length, which is a function of said length of feed or time of feed determined; and

ii) said unloading means (800, 900) so as to unload said bars, optionally cut, into a respective compartment of said plurality, selected on the basis of the length of feed or time of feed determined or of said pre-set length.
The plant according to Claim 8, wherein said sensor (101) is a proximity or presence sensor, or a movement sensor, associated to a reference point of said plant and designed to detect the presence or the movement of said individual bars at said reference point.
The plant according to any one of Claims 8 and 9, wherein said transfer means comprise a feed assembly with opposed rollers and wherein said sensor is associated to a roller (46C, 610) of said assembly.
The plant according to any one of Claims 8-10, wherein said control means are configured for enabling setting and/or modification of correspondences between the series of compartments of the second storage area (C1, C2, ..., Ci) and a series of ranges of values of length of the bars (X1-X2, X2-X3,..., Xi-Xi+1), and wherein said control means are configured for assigning respective compartments of said series to the individual bars on the basis of said correspondences after said length of feed or said time of feed has been determined.
The plant according to any one of Claims 8-11, wherein said control means are configured for enabling setting and/or modification of triple correspondences between the series of the compartments of the second storage area (C1, C2, ..., Ci), a series of pre-set lengths to be cut (X1', X2', ..., Xi'), and a corresponding series of ranges of values of length of the bars (X1-X2, X2-X3,..., Xi-Xi+1), and wherein said control means are configured for assigning respective values of pre-set lengths to be cut (X1', X2', ..., Xi') and respective compartments of said series (C1, C2, ..., Ci) to the individual bars on the basis of said correspondences after said length of feed or said time of feed has been determined.
The plant according to any one of Claims 8-12, wherein said control means are configured for storing, for each compartment of said series (C1, C2, ..., Ci), a number that identifies the number of bars unloaded therein, which is equal to zero at the start of operation of said plant, and updating it whenever a new bar is associated to said compartment after said length of feed or said time of feed of said bar has been determined.
The plant according to any one of Claims 8 to 13, wherein said one or more sensors (101) are configured for detecting passage of the individual bars in said respective reference point (P) of said plant, , so that, during said movement of feed, through said reference point there passes the entire portion of said individual bars that is initially located upstream of said reference point.