EP4709541A1 - Apparatus and method for receiving and unloading rolled bar - Google Patents

Abstract

Apparatus (10) for receiving and unloading bars (50), which are fed by a rolling plant (100) with an initial speed and a nominal length (NL); the apparatus (10) being provided with at least one speed modification unit (11) which is suitable to mechanically actuate a modification of the speed on the bars (50) until a desired release speed thereof is reached, and a rotating unit (12) suitable both to actuate a slowing down by friction on the bars (50) and also to feed a cooling plate (200); the rotating unit (12) comprising at least one rotating member having at least a first braking seating for the bars (50) divided longitudinally between a main portion (17) with a first length (LI) substantially corresponding at least to the nominal length (NL), and at least one additional portion (18), interposed between the speed modification unit (11) and the main portion (17), having a second length (L2) corresponding at least to a range comprised between about 2% and about 15% of the first length (L1).

Description

“APPARATUS AND METHOD FOR RECEIVING AND UNLOADING ROLLED BARS”

FIELD OF THE INVENTION The present invention concerns an apparatus and a corresponding method for processing, receiving and unloading rolled bars onto a cooling plate, by varying the speed of the bars coming from a rolling plant and then unloading them onto said cooling plate.

BACKGROUND OF THE INVENTION Devices are known which are suitable to receive rolled bars from a rolling plant, separate them and suitably sort them, and then unload them into suitable seatings of a cooling plate. These devices are normally disposed downstream of the rolling plant and are suitable to manage both bars, for example with diameters up to 50mm, and also metal wires from about 8mm up to about 20/25 mm in diameter. Examples of such devices are described in EP 1.877.203, EP 1.789.212, US 2019/275574 and EP 1.902.791.

The bars or metal wires can be selectively fed in single form or divided into pairs obtained through a splitting process. Operationally, the devices slow down the bars or wires until they are completely braked, so as to separate them, sort them and subsequently deposit them on suitable seatings of the cooling plate, which is disposed downstream of the rolling plant.

In particular, known devices are provided with one or more devices for modifying the speed of the bars, for example bar braking or bar accelerating devices with opposing rollers, which are suitable to move toward each other and exert a certain radial pressure on the bars at exit from the rolling plant, so as to substantially vary their speed.

It is also known that, to optimize scrap management, the bars are cut, at exit from the rolling plant, to sizes which are multiples of the commercial sizes, for example about 12m, trying to maximize the cut limit size, thus also being able to reach nominal bar sizes even beyond 120m.

Known devices are also provided with one or more rotating drums, having longitudinal housing channels for the bars, which carry out a coordinated action of slowing down the same bars by friction, until they stop, substantially totally, inside them.

The longitudinal channels of the drums are obtained substantially parallel to the direction of feed of the bars and have lengths coordinated with the maximum nominal length of the bars to be unloaded. In addition, the channels are disposed angularly offset from each other, so that a coordinated angular rotation of the drum allows to present, at each cycle, a free channel for the insertion and braking by friction of new bars and, at the same time, allows to take the previously inserted bars into a position of pre-unloading or unloading onto the cooling plate.

The latter also has, notoriously, a size coordinated with the maximum nominal length of the bars to be cooled.

For this reason, the drums are positioned immediately downstream of the bar speed modification devices and have substantially the same length as the cooling plate on which they will subsequently unload the bars thus decelerated.

Clearly, the higher the speed of the bar, the greater the contact pressure exerted by the speed modification devices and the longer contact length in the drum’s channels will need to be, in order to allow the bars to be stopped in a desired position.

However, although these speed modification devices can be structured to exert high values of contact force with the bar, in order to affect a braking or acceleration thereof, they cannot exert a pressure greater than a certain value, otherwise rolling would begin to be actuated, thus compromising the finishing carried out by the finishing stands of the rolling plant.

For this reason, and in order not to have to excessively increase the space, time and, therefore, the sizes in length of the drums, necessary for the correct braking by friction of the bars, known devices can manage bars coming from the rolling plant with speeds that do not exceed about 40-45 m/s.

In fact, a possible increase in the sizes of the drum and the plate, to guarantee the space necessary for deceleration up to the complete braking of the bars with speeds higher than those indicated, would entail both an increase in installation spaces and costs, and also a consequent increase in production costs and times, as well as significant decreases in the productivity of the device, with consequences also for the rolling plant.

In addition, as mentioned, the speed modification device can brake the bars up to a certain value, however this is not the only limit, since the actual limit is given by the arrival speed of the next bar and by the rotation time of the drum to change position, going from a position of receiving bars to a subsequent pre-unloading or unloading one. There is therefore the need to perfect an apparatus and to develop a corresponding method that can overcome at least one of the disadvantages of the state of the art.

To do this it is necessary to solve the technical problem of being able to satisfy a production of bars with diameters ranging from approximately 8 mm to approximately 50 mm, at a maximum rolling speed that can even exceed the current 40-45 m/s.

In particular, one purpose of the present invention is to provide an apparatus for unloading rolled bars which allows to slow down the bars from a rolling speed even higher than 40-45 m/s, until they are unloaded onto a corresponding cooling plate braked, substantially without having to excessively increase the space, time and, therefore, sizes, necessary for the correct deceleration until the bars are complete braked.

Another purpose of the present invention is to provide a device which allows to increase the speed limit for the arrival of the bar from the rolling plant, optimizing the rotation times of the drum, so as to increase the productivity of both the rolling plant and also of the device itself, with substantially the same manufacturing and installation times and costs as known devices.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea. In accordance with the above purposes and to resolve the technical problem disclosed above in a new and original way, also achieving considerable advantages compared to the state of the prior art, an apparatus according to the present invention is applied for receiving and unloading rolled bars into a cooling plate, by varying the speed at which the bars are fed from a rolling plant.

These bars can have a length substantially corresponding to the traditional commercial length, for example multiples of 6 meters, and in particular 12m or 18m, or even 16m, or they can have a length advantageously equal to a multiple of the commercial length, so as to optimize scrap management and reduce material waste to a minimum, considering any variations related to tolerances and thermal expansions, this length is defined as nominal length.

Since the length of the bars depends on the cut made by the cutting to size shear, in the present invention we will generally refer to the nominal length of the bars, since this length could also coincide with the commercial length.

The apparatus according to the present invention comprises at least one unit for modifying the speed of the bars, bar brake or bar accelerator, which is suitable to actuate a first mechanical action on the bars by contact, for example by means of opposing motorized rollers, so as to take them to an intermediate speed which can be, according to some examples, lower than the initial feeding speed, for bars with a small diameter and long length, in order to promote the braking in a certain position, or higher than the initial feeding speed, in the case of bars with a large diameter, in order to give the sufficient momentum to reach the desired braking position. Advantageously, the bar speed modification unit can be of the roller type, in which the rollers apply a desired radial pressure on the bars in transit in order to actuate a slowing down which is, as mentioned, of the mechanical type.

The apparatus according to the present invention also comprises, advantageously, at least one rotating unit, disposed downstream of the speed modification unit and suitable both to actuate a subsequent slowing down by friction on the bars, until it stops them, and also to unload the bars into a cooling plate.

In accordance with one aspect of the present invention, the rotating unit is provided with at least one rotating member, preferably between 2 and 4 rotating members, comprising at least a first braking seating for the bars which is divided longitudinally between a main portion and at least one additional front portion, the latter interposed between the speed modification unit and the main portion, and normally not occupied by the bar once the latter has passed and has been braked inside the main portion.

By the term “front” we mean the portion of the braking seating that the bar coming from the rolling plant encounters first.

In particular, the main portion, disposed downstream with respect to the direction of arrival of the bars, has a first length substantially corresponding to, or only slightly greater than, the nominal length of the bars to be braked and unloaded, while the additional front portion, disposed upstream, has a second length corresponding at least to a range comprised between about 2% and about 15% of the first. By doing so, an additional head front portion of the braking seating is interposed between the speed modification unit and the main portion of the braking seating itself, substantially increasing the friction contact surface thereof by a few percentage units with respect to the length of the bars.

This increase in surface area allows to lengthen both the friction braking time and space, allowing the bars to be fed at a higher speed than the traditional one, essentially without having to excessively increase the sizes necessary for the deceleration until the bars themselves are stopped.

Moreover, by keeping a main portion with a length at least equivalent to the nominal length of the bars, the cooling plate associated with the rotation member can also be sized according to at least the nominal length of the bars, without taking into account the additional portion. This solution, according to the present invention, allows the overall dimensions and installation costs of the cooling plate to be kept substantially unchanged.

In fact, the additional front portion protrudes forward with respect to the unloading seating of the cooling plate, the length of which instead substantially corresponds to the length of the main portion alone, of which it is substantially the projection.

The Applicant has advantageously identified that, with a length of the additional portion equal to approximately 2%-15% the length of the main portion of the rotating member, which corresponds to the nominal length of the bar, it is possible to effectively slow down and brake bars coming from the rolling plant even at speeds of approximately 60 m/s, using bar braking units essentially of the traditional type which do not exceed the braking force values provided. As mentioned, the additional front portion does not contain the bar once it is braked and completely disposed inside the main portion, but only acts as an aid to its speed variation during transit.

It is clear that by optimizing the design of the bar speed modification units it can be possible to reduce the length of the additional portion, with the same initial speed, as well as provide greater initial speeds, with the same length of the additional portion.

This advantage allows to increase the productivity of both the rolling plant and also the device itself, with substantially the same manufacturing and installation times and costs as known devices.

Another advantage deriving from the additional portion is the fact that the rotating member can start the rotation phase for feeding the bars to the cooling plate when a terminal end of the bar exits from the bar speed modification unit and enters the additional front portion located on the head of the rotating member. In this way, the rotation of the rotating member can be started while the bar is still in the braking phase, exploiting the additional head part of the braking seating, even if the unloading into the plate then occurs when the bar has substantially stopped in the corresponding seating, even if a slight residual speed can be tolerated during unloading, for example 1 m/s. In essence, the additional portion of the seating in the rotating member allows for an operating anticipation of a time proportional to its length, as a function of the intermediate speed of the bar at exit from the bar speed modification unit, releasing the bar at a higher speed, thus being able to recover some fractions of time for each bar which, in the long term, translate into a notable optimization of the operating times of the rotating member and an increase in productivity, at least, of the device according to the present invention.

In accordance with another aspect of the present invention, the rotating member is disposed substantially parallel to the axis along which the bars are fed. This advantageous solution allows to significantly simplify the layout of the device according to the present invention, for the purposes of a correct and efficient feed of a substantially traditional cooling plate.

In accordance with another aspect of the present invention, the rotating member comprises at least a second braking seating, which is angularly offset with respect to the first and extends longitudinally between the additional portion and the main portion.

Advantageously, each braking seating transversally defines one or more housing channels, open outward with respect to an external surface of the rotating member, and suitable to house corresponding bars.

This advantageous solution according to the present invention allows the rotating member to simultaneously manage several bars, whether single or in pairs (“splitting” in jargon), fed at different operating times. Consider, in fact, a system in which a first bar interacts with the first braking seating, and subsequently the rotating member carries out an axial rotation of an angle equal to the radial offset between the seatings, so that a second bar being fed can interact with the second braking seating, and so on.

In another advantageous embodiment of the device according to the present invention, two rotating members are provided disposed operatively in parallel, so as to allow a substantial increase in the operating speed and, consequently, in productivity.

In another advantageous embodiment of the device according to the present invention, four rotating members are provided disposed operatively in parallel, so as to allow a further substantial increase in productivity if the length of the bars is equal to a commercial length or a multiple thereof lower than 4.

In another embodiment of the device according to the present invention, three rotating members are provided disposed operatively in parallel, so as to allow a further substantial increase in productivity if the length of the bars is equal to a commercial length or a multiple thereof lower than 4. In this case, two of the three rotating members are used primarily, and the third is used as support in the event of split production, in the event of a high dynamic of arrival of the bars, for example in the case of bars with a small diameter which, due to the splitting process, accumulate arrival speeds excessively different from each other.

In these solutions with different rotating members, it is advantageous to provide one or more diverter members, which are disposed upstream of the bar speed modification unit, to alternately direct the bars gradually toward one of the rotating members.

In accordance with another aspect of the present invention, each rotating member consists of a plurality of modular elements, kinematically connected to each other by corresponding transmission joints.

Advantageously, the size of each module can be coordinated with, or with a multiple of, the aforementioned traditional commercial lengths of the bars. DESCRIPTION OF THE DRAWINGS

These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of an embodiment, given as a non- restrictive example with reference to the attached drawings wherein:

- fig. 1 schematically shows a lay-out of an embodiment of the device according to the present invention, applied to a traditional rolling plant for producing metal bars or wires;

- fig. 2 shows an enlarged detail of fig. 1 ;

- figs. 3a and 3b schematically show two first variants of fig. 1 , with the long drum;

- fig. 4 schematically shows a second variant of fig. 1 ; - fig. 5 shows a cross section of fig. 2;

- figs, from 5a to 5e show a first operating sequence of fig. 5;

- figs, from 6a to 6b show a second operating sequence of fig. 5;

- fig. 7 is a graphic extract of the space-time relationship in deceleration carried out by the device of fig. 1 ; - fig. 8 is an enlarged detail of fig. 2.

We must clarify that the phraseology and terminology used in the present description, as well as the figures in the attached drawings also in relation as to how described, have the sole function of better illustrating and explaining the present invention, their purpose being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can be conveniently combined or incorporated into other embodiments without further clarifications. DESCRIPTION OF AN EMBODIMENT OF THE PRESENT INVENTION

With reference to fig. 1, an apparatus 10 according to the present invention is applied for receiving and unloading a metal bar, or wire, 50 coming from a rolling plant 100, modifying its speed, in order to feed a cooling plate 200, forming part of the apparatus, in which the bars, or wires, 50 are traditionally deposited once they have been rolled.

Here and hereafter in the description, with the terms bar and wire, both indicated numerically with the same reference number 50, we mean, in general, metal products with a preferably circular section, but not only, in which the prevailing dimension is in any case the length, which are obtained at the end of a rolling process starting from a billet, or from continuous casting, or other known methodologies. In this description, we have chosen a terminological distinction between bar and wire, as a function of the diameter size of the rolled metal product, which can range from about 8mm to about 25mm in diameter for metal wires, and from about 25mm to about 50mm in diameter for metal bars.

In the rolling plant 100, partly shown in fig. 1, the bars or wires 50 at exit from the finishing stands (not shown) can follow two different feeding paths, chosen according to whether or not the rolled product has to undergo a division, “splitting” in jargon, in order to simultaneously feed one or two bars or wires 50 to the device

10.

Below is a brief description of the two known feeding methodologies, provided for the sole purpose of better understanding the functionalities of the device 10 according to the present invention, which will be disclosed below. If feeding two bars or wires 50 simultaneously, once the finishing rolling of the bar or wire 50 has been performed, the latter transits through corresponding splitting stands 110 giving rise to two rods or wires 50, which advance simultaneously on two different diverging feeding lines, I l la and 111b, respectively, advantageously passing through respective finishing blocks 112 and quenching units 113 which, according to other embodiments and in any case being within the scope of the solution according to the present invention, could also be disposed upstream of the finishing units. As a rule, upstream of the finishing blocks 112 respective scrapping/emergency shears 117 are provided.

The two feeding lines I l la and 111b subsequently converge upstream of one or more cutting shears 114, by means of which the bars or wires 50 are cut to size.

If feeding a single bar or wire 50, a size distinction must be made. In fact, in the case of wires 50 with diameters from 8mm to 25mm, the wire 50 preferably, but not exclusively, follows a path analogous to that of the double feed described above, without it being split, that is, one wire 50 following the other, alternatively, they are directed to travel one or the other of the feeding lines I l la and 111b.

Alternatively, for bars with diameters that can range from 8mm to 50mm the path can be different, the bars in fact preferentially transit through the central duct 115 and pass through a series of quenching units 113 in order to reach the cutting shear 114 to be cut to size.

Advantageously, the cutting to size of the bars or wires 50, whether fed individually or in pairs, occurs in an optimized manner to obtain both a nominal length NL of about 120m and also as a function of the lengths suitable for transport by truck which, in this case, are preferably multiples of 6 meters, for example 12 or 18 meters, or 16 meters.

In addition, two pinch rolls 116 are provided upstream and downstream of the cutting shear 114.

The upstream pinch roll 116 has the function of taking the bars or wires 50 to the cutting shear 114, which performs a cut preferably maintaining the speed of the bar (in fact, the cutting can occur at the same speed of travel of the bars or wires 50); the downstream pinch roll 116 has the function of gripping the heads of the cut bars or wires 50 in order to send them to the device 10 according to the present invention, with speed management capacities even greater than about 60 m/s, as a function of the size and temperature parameters of the same bars or wires 50.

The device 10 according to the present invention comprises substantially one or more units 11 for modifying the speed of the bars, a rotating drum unit 12 and preferably a diverter 13.

The diverter 13 is of a substantially traditional type and has the purpose of alternately directing the cut bars or wires 50 toward a first feeding line 14a or alternative feeding lines 14b of the speed modification unit 11 and of the drum unit 12.

The bar speed modification unit 11 preferably comprises two roller units, respectively a first 15a and a second 15b, each operatively associated with a respective one of either the first 14a or the second feeding line 14b.

Each of these units 15a and 15b operates in a substantially traditional manner, wherein the rollers exert a defined radial pressure on the bars or wires 50 in transit, in order to establish a mechanical contact until they are taken to a desired release speed, without compromising the rolling finish. This release speed can correspond to a slowing down for products with a smaller diameter (e.g. wires) or an acceleration for products with a larger diameter (e.g. bars), so as to allow sending to downstream devices and to stop the product at the desired distances thanks to friction, as described below.

The bar speed modification units 11, as seen equipped with rollers 15a and 15b, are distanced from the pinch roll 116 downstream of the shear 114 by a certain distance D, chosen as a function of the maximum tail length necessary to brake the type of bar or wire 50 passing at the maximum initial speed SV of about 60 m/s. This distance D is, in fact, strongly determined by the maximum deceleration achievable by the roller bar brakes 15a and 15b, and can vary in coordination with the operating functions of the roller bar brakes 15a and 15b, designed and installed on each occasion.

The drum unit 12 is disposed immediately downstream of the speed modification unit 11 and preferably comprises a pair of rotating drums, first 16a and second 16b, respectively, disposed substantially parallel to each other and to the feeding lines 14a and 14b.

According to the variants shown in figs. 3a, 3b and 4, a single shear 114, preferably two shears 114 in parallel, can be provided for managing the split. In the event bars 50 of a commercial length are to be made directly, however, it is possible to double the number of drums 12.

In particular, each drum 16a and 16b is operatively associated with a respective one of either the first 14a or the second 14b feeding line and, consequently, with the respective speed modification units 11, as shown in fig. 2. In this way, by means of the diverter 13, the bars or wires 50 are alternately sent on the first line 14a or on the second line 14b so as to feed, in a consequently alternate manner, the first drum 16a or the second drum 16b with bars of nominal length.

If producing bars of a commercial length, on the other hand, since the drums are shorter, the lines downstream of the shear 114 are split and each is connected to two drums 16a or 16b, the bars or wires 50 are alternately sent to one of the drums 16a or 16b, forming part of the pair of each line.

The subsequent bars or wires 50 cut by the shear 114 will be fed, vice versa, by the diverter 13 on the second line 14b or on the first line 14a so as to inversely feed the second drum 16b or the first drum 16a.

Each drum 16a or 16b longitudinally provides a main portion 17 having a length LI at least equal to the nominal length NL of the bars or wires 50, and an additional head front portion 18 having a length L2 equal, in this case, to about 3-7% of the length LI.

Clearly, although an additional length L2 comprised in the range between 3-7% of the length LI is specifically described and shown, it is not excluded that the additional portion 18 can provide an additional length L2 corresponding to a different percentage, for example comprised between 2% and 15%, or different but still falling within the range defined by the present invention.

The front additional portion 18 does not have the function of containing the bar or wire 50, in fact it protrudes frontally with respect to a corresponding unloading seating of the cooling plate 200. In fact, its function is to collaborate in varying, in particular braking, the speed of arrival of the bar or wire 50, which is then completely positioned in the respective main portion 17.

The scope of present invention can also include solutions in which, as a function of the production parameters of the metal products to be obtained, as well as the sizing and/or operation of the bar brakes 15a and 15b, this length L2 can be reduced in a coordinated manner, that is, slightly increased, in order to feed the bars or wires 50 to the plate 200 according to the predefined feeding parameters.

Moreover, each drum 16a and 16b comprises a plurality of braking seatings 19, which extend longitudinally both along the additional portion 18 and also along the main portion 17, and have at least one operating condition substantially aligned with the respective feeding line 14a or 14b.

As shown in detail in fig. 5, each braking seating 19 is obtained angularly offset with respect to a subsequent braking seating 19, so that an axial rotation of the corresponding drum 16a or 16b, by a coordinated angular dimension, allows a progressive positioning of a new braking seating 19 in the aforementioned operating position aligned with the respective feeding line 14a or 14b.

In addition, each braking seating 19 transversally defines one or two housing channels 20, depending on whether it is suitable to receive bars or wires 50, fed in pairs or individually. Each housing channel 20 is open toward the external surface of the corresponding drum 16a or 16b, so as to allow the bars to be unloaded onto the cooling plate 200 by gravity.

In the advantageous solution shown in the attached drawings, with particular reference to fig. 8, each drum 16a or 16b substantially consists of a plurality of modules 21 kinematically connected to each other by corresponding transmission joints 22, wherein these modules preferentially have sizes of 6 meters, corresponding to the minimum size of a commercial bar, or a multiple thereof, so that devices 10 can be selectively set up for the effective variation of the speed of bars or wires 50 having different nominal sizes from those indicated so far, without requiring complex designs, to the advantage of production and installation times and costs of the device 10 itself.

With reference to the operating sequence schematized in figs, from 5a to 5e, we have considered the case in which metal wires or bars 50 are fed in pairs. As can be seen in fig. 5a, the first drum 16a is rotated with a first braking seating 19 thereof substantially aligned with the first feeding line 14a, so that the two housing channels 20 can simultaneously house the two wires 50 being fed.

In the subsequent operating step schematized in fig. 5b, the first drum 16a rotates by about 90°, in an anticlockwise direction according to the direction of representation, taking the two wires 50 to a pre-unloading position and preparing a new braking seating 19 substantially aligned with the first feeding line 14a. The second drum 16b is located with a first braking seating 19 thereof substantially aligned with the second feeding line 14b, in order to accommodate two new wires 50.

Subsequently, as shown in fig. 5c, the second drum 16b rotates by about 90°, in a clockwise direction according to the direction of representation, taking the two wires 50 to a pre-unloading position and preparing a new braking seating 19 substantially aligned with the second feeding line 14b. In this same operating step, two new wires 50 are housed in the two free housing channels 20 of the first drum 16a. Fig. 5d shows that the first drum 16a rotates by a further 90°, in an anticlockwise direction, taking the two wires 50 housed in the housing channels 20 in fig. 5a to a position of unloading onto the plate 200, and the wires 50 housed in the housing channels 20 in fig. 5c to a pre-unloading position. As previously described, a new braking seating 19 is substantially aligned with the first feeding line 14a. In this same operating step, two new wires 50 are housed in the two free housing channels 20 of the second drum 16b.

Finally, fig. 5e shows that the second drum 16b rotates by a further 90°, in a clockwise direction, taking the two wires 50 housed in the housing channels 20 in fig. 5b to a position of unloading onto the plate 200, and the wires 50 housed in the housing channels 20 in fig. 5d to a pre-unloading position. Also in this case, a new braking seating 19 is substantially aligned with the second feeding line 14b. In this same operating step, two new wires 50 are housed in the two free housing channels 20 of the first drum 16a.

The cycle of feeding two new wires 50 into the first drum 16a and the subsequent unloading of the wires of the second drum 16b onto the plate 200 thus resumes, and so on.

With reference to the operating sequence schematized in figs. 6a and 6b, we have considered the case of a single feed of metal bars 50.

In a substantially similar way to the previous case, the first drum 16a is rotated with a first braking seating 19 thereof substantially aligned with the first feeding line 14a, so that the single housing channel 20 can house the bar 50 being fed.

In the subsequent operating step schematized in fig. 6b, the first drum 16a rotates by about 180° so that the bar 50 housed therein is taken directly into a position of unloading onto the plate 200, while the second drum 16b is located with a first braking seating 19 thereof substantially aligned with the second feeding line 14b in order to accommodate a new bar 50.

Subsequently, both drums 16a and 16b perform a further coordinated and alternating rotation of about 180°, and the bars 50 housed in the second drum 15b are taken into the position of unloading onto the plate 200.

The cycle of feeding two new wires 50 into the first drum 16a and the subsequent unloading onto the plate 200 thus resumes, and so on.

In both solutions, the passage from the position of accommodating the new bars or wires 50 to the pre-unloading position, or directly to the position of unloading onto the plate 200, can provide an operating anticipation with respect to the complete braking of the bar or wire 50, housed in the respective braking seatings 19, precisely due to the presence of the additional portion 18, which guarantees the minimum space sufficient for the bar or wire 50 to stop by friction additionally to the main portion 17.

This solution guarantees a time anticipation equal to the time required to travel the length L2 at the intermediate speed IV of the bar or wire 50 at exit from the speed modification unit 11. This anticipation, if added to the number of bars or wires 50 traveling in a unit of time, results in a significant optimization in terms of reduction of the operating times of the drums 16a and 16b, and an overall increase in productivity.

With reference to the graph shown in fig. 7, this shows the kinematics of the bars or wires 50 during the mechanical braking steps in the speed modification unit

11 , wherein the two curves, respectively indicated with reference letters H and T, represent the speed variations of the head and tail of the bars or wires 50.

For a better understanding, bars or wires 50 have been schematized inside the two curves, in different positions substantially between the scrapping/emergency shears 117 and the inlet of the drum unit 12.

In particular, this graph allows to identify the actual length TL of the terminal segment of the bar or wire 50 on which the speed modification devices 11 have to act, in order to reach the desired intermediate speed IV of entry into the drum unit

12. In particular, this length TL strongly depends on the kinetic modification carried out by the roller devices 15a and 15b, and is limited by several factors, as stated the maximum impressible force, in order not to deform the bar or wire 50, as a function of the temperature and diameter thereof, and operating and mechanical limits of force and drive of the roller bar brakes 15a and 15b used. In any case, this length has to be shorter than the distance D, identified between the modification devices 11 and the pinch rolls 116 downstream of the shear 114.

Operationally, as can be seen from the variation in the slope of the curve T at the beginning of the length TL, the bar or wire 50 begins to be braked with the maximum deceleration that can be impressed with the roller bar brakes 15a and 15b engaged.

This deceleration is then reduced until a substantial stabilization is reached, to then be released by the roller bar brakes 15a and 15b with the specific intermediate speed IV. In the last segment of the two curves H and T of the graph, in particular after the entry into the drum unit 12, there is a further angular variation in the trend of the curves themselves, due to the frictional braking action of the bars or wires 50, in the corresponding braking seatings 19. This braking segment has a length SL, which is substantially equivalent to, or slightly greater than, the length L2 of the additional segment 18.

In another embodiment of the apparatus according to the present invention, shown in fig. 3b, three rotating members 16a, 16b, 16c are provided disposed operatively in parallel, so as to allow another substantial increase in productivity if the length of the bars 50 is equal to a commercial length, or a multiple thereof smaller than 4. In this case, two of the three rotating members, for example 16a, 16b, are mainly used, and the third 16c is used as support in the case of split production, in the event of a high dynamic of arrival of the bars 50, for example in the case of bars 50 with a small diameter and which, due to the splitting process, accumulate an excessively different arrival speed from each other. In this case, in fact, one of the two bars 50 will be thicker than the other, and therefore slower. Since in order to start the rotation of the rotating member 16a, 16b, 16c it is necessary for the bar 50 to no longer be in contact with the respective speed modification unit, it is necessary to wait a longer amount of time in the case of a slow bar in order to be able to carry out the operation. This, however, is a risk, because in order to produce a bar 50 of the same size as the parallel one that proceeds at a higher speed, waiting for the corresponding amount of time before starting the rotation of the rotating member, there is a risk of the subsequent bars jamming. To at least partly overcome this risk, it is possible to cut the slow bar to a size smaller than that of the fast bar, preferably a shorter commercial length, in order to minimize waste. In this way, the contact time of the short bar with the respective speed modification unit is shorter and the rotation of the rotating member 16a, 16b, 16c can begin earlier. However, even this measure may not be sufficient for bars with a very small diameter, for example less than 12mm.

In this case, the present invention provides to equip the device 10 with a third rotating member 16c next to the first two, so as to periodically unload at least the slowest bar onto this member, thus being able to use the other two rotating members 16a, 16b to unload the subsequent bars without risk of jamming.

In any case, it is possible to unload both the slower bar and also the faster parallel bar into the third rotating member 16c, therefore in the presence of at least one excessively slow bar the third rotating member is used, while the other two members are used to operate at target speeds.

It is clear that modifications and/or additions of parts may be made to the device 10 and method as described heretofore, without departing from the field and scope of the present invention, as defined by the claims. It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art will be able to achieve other equivalent forms of device and method for producing and unloading rolled bars, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

1. Apparatus (10) for receiving and unloading rolled bars (50), which are fed by a rolling plant (100), wherein the bars (50) have an initial speed (SV) and a nominal length (NL), said apparatus being provided with at least one speed modification unit (11) which is suitable to mechanically actuate a modification of the speed of said bars (50), and a rotating unit (12) suitable both to actuate a slowing down by friction on said bars (50) and also to unload said bars (50) onto a cooling plate (200) of said apparatus, said rotating unit (12) comprising at least one rotating member (16a, 16b, 16c) comprising at least one braking seating (19) for said bars (50), characterized in that said braking seating (19) is divided longitudinally between a main portion (17) having a first length (LI) corresponding at least to said nominal length (NL) and an additional front portion (18), interposed between said speed modification unit (11) and said main portion (17), and having a second length (L2) corresponding at least to a range comprised between about 2% and about 15% of said first length (LI), and in that said additional portion (18) projects forward, toward said speed modification unit (11), with respect to an unloading seating of the cooling plate (200), the latter having a length substantially equal to said main portion (17) and being disposed in substantial projection thereof.

2. Apparatus (10) as in claim 1, characterized in that said at least one rotating member (16a, 16b) comprises at least a second braking seating (19), angularly offset with respect to said first braking seating (19) and extending longitudinally between said main portion (17) and said additional portion (18).

3. Apparatus (10) as in claim 2, characterized in that each one of either said first braking seating (19) or said second braking seating (19) transversally defines a housing channel (20) suitable to house one of said bars (50).

4. Apparatus (10) as in claim 2, characterized in that each one of either said first braking seating (19) or said second braking seating (19) transversally defines two housing channels (20) suitable to house two of said bars (50) simultaneously.

5. Apparatus (10) as in one or the other of claims 3 or 4, characterized in that said housing channels (20) are open toward the outside with respect to an external surface of said rotating member (16a, 16b).

6. Apparatus (10) as in any claim hereinbefore, characterized in that said rotating unit (12) comprises two rotating members (16a, 16b) disposed substantially parallel to each other.

7. Apparatus (10) as in any claim hereinbefore, characterized in that said rotating unit (12) comprises four rotating members (16a, 16b) disposed operatively in parallel to each other.

8. Apparatus (10) as in any claim hereinbefore, characterized in that said rotating member (16a, 16b) consists of a plurality of modular elements (21) kinematically connected to each other by corresponding transmission joints (22).

9. Method for receiving and unloading rolled bars (50) which are fed by a rolling plant (100) with an initial speed (SV) and a nominal length (NL), providing at least a first step in which the speed of said bars (50) is modified by means of at least one speed modification unit (11), at least one step of braking said bars (50) in which by means of at least one rotating unit (12) a slowing down by friction is implemented on said bars (50), and a feeding step in which by means of said rotating unit (12) said bars (50) are unloaded onto a cooling plate (200), wherein said rotating unit (12) comprises at least one rotating member (16a, 16b) comprising at least a first braking seating (19) for said bars (50) divided longitudinally between a main portion (17) having a first length (LI) substantially corresponding to at least said nominal length (NL), and at least one additional front portion (18), protruding frontally from a corresponding portion of said cooling plate (200), interposed between said speed modification unit (11) and said main portion (17), and having a second length (L2) corresponding at least to a range comprised between about 2% and about 15 % of said first length (LI), and wherein said feeding step begins when a terminal end of said bars (50) exits from said speed modification unit (11) and enters said additional front portion (18).