METHOD AND APPARATUS FOR FEEDING THREADLIKE METAL MATERIALS

Technical field

[01] The present invention relates to a method and an apparatus for feeding threadlike metal materials, in particular metal wires in rolls to be fed to the stations of straightening, cutting and, if necessary, bending of such materials.

Background of the invention

[02] Apparatuses are known that feed threadlike metal materials, in particular metal wires, to be used for making reinforcement bars for reinforced concrete, such as for example bars, nets, shaped wires or stirrups.

[03] Such apparatuses may be fed from threadlike material unwound from reels or rolls, rather than from material already cut into bars, since producing from reels or rolls allows to work more quickly, without intermediate stops between one piece and another, producing relatively less processing waste from already cut bars. In this regard, it can be observed that in the processing of already cut bars, a piece of waste is generally produced for each piece, while in the processing from a reel or roll, only one piece of waste is produced when the reel is completely unwound.

[04] It should be noted that the material in reels or rolls must be properly straightened, before being subjected to subsequent cutting and/or bending processing.

[05] Therefore, the known apparatuses generally comprise a straightening unit, for example of the roller type, associated with a cutting unit, for example of the shear type.

[06] Apparatuses of the known type usually comprise, upstream of the feeding apparatus, a set of reels, able to house a corresponding number of reels or rolls, ready to be used.

[07] For example, the patent IT 1423952 of the same applicant illustrates a device for replacing threadlike metal materials to be fed into an apparatus for processing the aforesaid materials, comprising a first section and a second loading section, each having at least one respective introduction portion to grip at least one said threadlike material from an unwinding area, in order to feed it to an inlet zone of the apparatus.

[08] Patent EP 1864726 discloses a device for feeding metal bars wound in rolls into an operating machine. The device comprises a load unit in which one or more rolls of wire are provided, and a drawing and straightening unit mounted on the operating machine so as to draw and straighten the wire and feed it to respective operating members of the operating machine.

[09] Apparatuses of the known type have the drawback of requiring long pauses for replacing the wire to be fed, when the wire of a reel or a roll has been used up.

[10] In particular, in this circumstance it is necessary to extract from the operating members of the apparatus the final portion of the material of the reel or of the finished roll and instead insert the initial portion of the material of a reel or of a new roll.

[11] For safety reasons, when changing the reel or the roll it is not possible for the operators to intervene on the operating apparatus, since the motion of the reel or roll and of the raw material itself can cause impacts, dragging and abrasion.

[12] Therefore, whenever the introduction of the threadlike material to be fed from a new reel or roll is required, it is necessary to deactivate the apparatus so as to enable the operators to approach the unwinding station of the reels and to carry out safely the operations of extraction of the material in exhaustion and of insertion of the new material.

[13] More precisely, the replacement operations involve a number of operating steps, in particular the backward insertion of a drawing cable throughout the path that the initial part of the new reel must perform, the connection by means of a clamp, for example, between the drawing cable and the initial part of the new reel, the actuation of a winch for positioning the new reel and the action of guiding the thread during the drawing operations at reduced speed, finally the insertion of the initial part of the new reel in the device of the wire feeder into the machine.

[14] Moreover, these apparatuses are usually provided with safety barriers, of a physical and/or photoelectric type, capable of suitably isolating the operating areas which are in movement during operation, preventing access to the operators. Therefore, the insertion of the threadlike material requires the total deactivation of the apparatus, which enables the opening of the aforesaid safety barriers and the access of the operators into the loading area of the reels. Only after the insertion operations are completed, then after a pause of at least twenty minutes, it is possible to activate the safety barriers again, suitably isolating the operating areas potentially risky for the operators and reactivating the apparatus.

[15] Therefore, the apparatuses of the known type do not fully satisfy the requirements of the specific sector, in particular as regards the productivity which is thus penalised by the forced stop for changing the reel, especially because of the time necessary to carry out the laborious replacement operations.

Disclosure

[16] The aim of the present invention is to solve the above problems by devising a method and an apparatus for feeding threadlike metal materials, in particular metal wires to be fed into respective units of straightening, cutting and, if necessary, bending of such materials, which permits to fully satisfy production needs.

[17] In particular, it is an object of the present invention to devise a method and an apparatus for feeding threadlike metal materials, which permit the insertion of the threadlike material to be fed quickly, easily and safely when a reel or a roll is finished or is running low.

[18] In particular, it is an object of the invention to devise a method and an apparatus which enable the insertion of threadlike metal materials to be carried out, without requiring production stops or significantly limiting their duration.

[19] Within this aim, it is a further object of the present invention to provide an apparatus for feeding threadlike metal materials, of simple constructive and functional conception, having a safe and reliable use, as well as a relatively inexpensive cost.

[20] The aforementioned objects are achieved, according to the present invention, by the method for feeding threadlike metal materials according to claim 1 , as well as by the apparatus according to claim 13.

[21] The method according to the invention provides for feeding along a feeding direction at least one first threadlike metal material coming from a first reel arranged in a first unwinding station of an unwinding zone of an apparatus for feeding the aforesaid material to a drawing and straightening unit through an insertion device; for detecting the exhaustion of the first reel, as well as for actuating cutting means positioned in a working position downstream of the insertion device, separating a corresponding end portion of the first threadlike metal material gripped by the insertion device.

[22] The method also preferably provides for the selective deactivation of a first segregation perimeter of a protecting system for the unwinding zone in which the first reel is installed, so as to make it accessible.

[23] The method further provides for preparing a further first reel in the first unwinding station made accessible, preferably, by the selective deactivation of the first isolation perimeter or by the pause of the apparatus and for joining the terminal end of the separate terminal portion with an initial end of the additional first reel arranged.

[24] The union of the further first reel with the terminal end of the first reel in exhaustion occurs in a joining position at the first unwinding station, therefore in an optimal position, in complete safety.

[25] The method thus allows a further reel to be arranged and inserted when a reel is exhausted, which, thanks to the union with the end portion of the exhausted reel, gripped by the insertion device, is already introduced into the apparatus, ready to be used.

[26] This circumstance is particularly advantageous because it avoids long operations and therefore stops for inserting a new reel.

[27] Preferably the step of preparing the further first reel is at least partially overlapping on the step of actuating the insertion device so as to feed a second threadlike metal material to the drawing and straightening unit and immediately continue the interrupted feeding due to the exhaustion of the first threadlike metal material. This makes it possible to replace the finished reel while the processing continues with the use of the second reel, previously prepared and inserted in the insertion device.

[28] Preferably, the step of actuating the cutting means takes place by means of a cutting unit arranged advantageously in a position interposed between the insertion device and the drawing and straightening unit.

[29] Preferably, the step of actuating the cutting means includes the step of positioning the cutting unit from a parking area spaced away from the position interposed between the insertion device and the drawing and straightening unit.

[30] The aforesaid step of actuating cutting means can take place alternatively by manual means.

[31] The step of actuating cutting means can take place by means of a cutting device integrated in the drawing and straightening unit.

[32] Preferably, the introduction unit provides for a motion for aligning a respective inlet section to the drawing and straightening unit. Advantageously, this alignment motion may be a translation in a direction, for example horizontal, which is orthogonal to the cutting motion, for example of vertical translation, performed by the aforesaid cutting means, so as not to interfere with each other.

[33] Alternatively, the aforementioned cutting unit is movable between a remote position and the aforesaid interposed position, to avoid interference with the insertion device.

[34] Alternatively, the cutting unit is shaped so as not to interfere with the aforesaid alignment motion of the introduction unit of the threadlike metal material.

[35] According to an aspect of the invention, the method may provide for interrupting the supply of the first threadlike metal material and subsequently moving the aforesaid terminal portion in a direction opposite to said feeding direction by means of the drawing and straightening unit or by further drawing means associated with the insertion device, so as to bring a terminal end of the terminal portion within the unwinding station for carrying out the operations of joining to the replacement reel and, at the same time, the terminal portion itself remains gripped by the insertion device of the threadlike metal material, to be immediately available for subsequent use together with the replaced reel.

[36] According to a further aspect of the invention the aforesaid step of detecting the exhaustion of the first reel takes place by detecting means through the detection of a datum indicating the exhaustion of the threadlike material. In particular, this detection relates to the unwinding of the aforementioned terminal end of the aforesaid first threadlike metal material fed by the aforesaid first reel.

[37] The apparatus according to the invention comprises a drawing and straightening unit for feeding at least one threadlike metal material, an unwinding area comprising at least a first unwinding station for housing a first reel in which a first threadlike metal material is wound and a second unwinding station for housing a second reel in which a second threadlike metal material is wound, a device for introducing the first threadlike metal material and the second threadlike metal material, interposed between the unwinding area and the aforesaid drawing and straightening unit.

[38] The apparatus may usefully comprise an isolation system for the unwinding area, comprising a first isolation perimeter for the first unwinding station and a second isolation perimeter for the second unwinding station, which may be deactivated selectively to make the first unwinding station and the second unwinding station independent one from the other.

[39] According to a particular aspect of the invention, detection means configured to detect a datum indicating the exhaustion of the first reel may be provided.

[40] The apparatus according to the invention usefully comprises a cutting unit in a position interposed between the insertion device and the drawing and straightening unit, configured to separate an end portion of the threadlike metal material being unwound from a respective reel, so as to maintain the separate terminal portion gripped by the insertion device. Alternatively, the apparatus according to the invention usefully comprises, instead of a cutting unit permanently associated with the apparatus, a housing arranged along the feeding direction in a position interposed between the insertion device and the drawing and straightening unit, configured to be alternatively closed preferably by safety barriers or accessible to the insertion, also manually, of a cutting member able to separate an end portion of a threadlike metal material being unwound from a respective reel, when the safety conditions are met, maintaining the separate terminal portion gripped by the insertion device.

[41] In particular, the aforementioned housing is configured to be alternatively closed or made accessible to the insertion of the aforesaid cutting unit, for example by providing protection means which may be opened, fixed or mobile, of a physical and/or immaterial type, for example photoelectric by providing a protective casing associated with a safety microswitch or a photocell or similar, single or multiple, means.

[42] The cutting unit, in any case, may be operated automatically between the aforesaid interposed working position and a position spaced from the feeding line of the threadlike metal material.

[43] The apparatus may usefully comprise a control unit configured to automatically implement the steps of the method according to the invention, keeping the apparatus safe, therefore, in particular, by selectively deactivating the isolation system of the unwinding area, or the same apparatus, so as to make a perimeter of unwinding or the aforementioned housing individually accessible, in the event of warning, preferably by the aforementioned detection means, that the respective reel is being exhausted.

Description of drawings

[44] The details of the invention will become more evident from the detailed description of a preferred embodiment of the apparatus for feeding threadlike metal materials according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, where:

Figures 1a, 1 b, 1 c, 1 d, 1 e respectively show a schematic plan view of an apparatus for feeding threadlike metal materials according to the invention, in different operating steps; Figures 2a, 2b, 2c, 2d respectively show a schematic plan view of a different embodiment of the apparatus according to the invention in different operating steps.

Best mode

[45] With particular reference to the figures, the reference numeral 1 indicates an apparatus for feeding threadlike metal materials, preferably metal wires 2, 2' to be fed for example to a cutting station in bars or in other reinforcement products.

[46] More particularly, the apparatus 1 comprises a drawing and straightening unit 3, for example of the roller or rotor type, for feeding the aforementioned threadlike metal material 2, 2' along a feeding direction A.

[47] The apparatus 1 shown in the figure comprises an unwinding area 4, where, in respective unwinding stations, respective reels or rolls, in which thread-like materials to be fed are initially wound, are housed.

[48] More precisely, the unwinding area 4 comprises a first unwinding station 41 in which a first reel 5 is housed, and at least one second unwinding station 42 in which a second reel 5' is housed. Consequently, from the first reel 5 a first threadlike metal material 2 may be fed and from the second reel 5', respectively, a second threadlike metal material 2'.

[49] Each unwinding station may comprise any accessory devices for the unwinding of the respective threadlike metal material, for example guide devices.

[50] Further embodiments of the apparatus according to the invention may be provided, comprising a different number of items of the aforesaid unwinding stations.

[51] The apparatus further comprises an insertion device 6, provided with respective inlet sections for the threadlike metal materials 2, 2' coming from the respective unwinding stations 41 , 42. More precisely, each input section, in a known manner, is configured to hold and guide, if necessary, a respective threadlike metal material inserted therein. In a known manner, different threadlike materials from respective reels 5, 5' may be arranged in respective inlet sections of the insertion device 6 and each inlet section may be selectively aligned, according to an alignment motion, to the feeding direction A to feed a respective threadlike metal material 2, 2' inserted therein, thus allowing, for example, a rapid replacement of the material being processed.

[52] The apparatus 1 preferably also comprises an isolation system 7 made by means of suitable physical, immaterial barriers or a combination thereof, capable of ensuring controlled access to the unwinding area 4, in particular by activating the protection where the threadlike metal material is being unwound. [53] More precisely, the isolation system 7 preferably enables the protection for each unwinding station 41 , 42 to be selectively deactivated individually, so as to make even one of them accessible, while the remaining unwinding stations remain protected and therefore usable for feeding the drawing and straightening unit 3.

[54] In the illustrated case, for example, the isolation system 7 comprises a protecting perimeter for each of the four represented unwinding stations (see Figures 1 a to 1e), in particular a first protecting perimeter 71 for the first unwinding station 41 and a second protecting perimeter 72 for the second unwinding station 42. Each perimeter may preferably be deactivated individually, thus making the respective unwinding station accessible.

[55] The apparatus 1 preferably comprises a control unit configured to selectively deactivate or activate the aforementioned isolation perimeters, as described in detail below.

[56] The apparatus 1 according to the invention also comprises cutting means 8 preferably arranged or positionable in a working position interposed between the insertion device 6 and the drawing unit 3 or in any case downstream of the insertion device 6.

[57] These cutting means 8 are preferably additional to usually provided cutting means, integrated in the drawing and straightening unit 3.

[58] The cutting means 8 are preferably made by means of a cutting unit 80, for example of the shear type.

[59] The cutting unit 80 is preferably operable alternately between a position spaced away and the aforementioned interposed position, so as to cut, if necessary, the threadlike metal material 2, 2', in appropriate phase relationship to the unwinding of the respective reel 5, 5'. In particular, the cutting unit 80 is operable so as not to interfere with the performance of other operating phases of the apparatus, in particular with the alignment motion of the insertion device 6 for changing the threadlike metal material to be fed.

[60] More precisely, the cutting unit 80 or equivalent means, also manual, serve to separate from the remaining threadlike metal material 2, 2' a terminal portion 20 of a reel 5, 5' in exhaustion, so that it extends up to the unwinding station involved, to be joined therein, at a joining position U, at an initial end of a new reel and in any case retained by the insertion device 6 arranged upstream (see Figure 1 c).

[61] The apparatus 1 may also comprise one or more detection means 9, for example optical, mechanical, electrical, magnetic or microwave, or have recourse to the operator, in order to detect a datum indicating the exhaustion of the reel 5, 5' being unwound.

[62] In practice, the detection means 9 detect the unwinding of a terminal end 21 of the threadlike metal material, for example the first threadlike metal material 2 being unwound, to enable the cutting of the end portion 20 and the joining of the respective terminal end 21 to an initial portion of a further first reel 5, subsequently installed in the same unwinding station 41 , replacing the first finished reel 5 to be activated in a suitable phase relationship. Advantageously the union of the initial end of the new reel with the terminal end 21 of the terminal portion 20 may be carried out in masked time and in complete safety, because in the meantime the insertion device 6, operated according to the aforementioned alignment motion, is capable of feeding a further threadlike metallic material 2' already arranged in a respective inlet section.

[63] The apparatus 1 may comprise suitable warning means, for example of a luminous type, able to warn the operator of the possible deactivation of the isolation perimeter 71 or of the pause of the apparatus 1 , so that he may safely access the respective unwinding station 41 and carry out the aforementioned union.

[64] The operation of the apparatus 1 according to the invention, which implements the method for feeding threadlike metal material, is understandable from the preceding description.

[65] In an initial preparation phase the first reel 5 and the second reel 5' are positioned, respectively, in the first unwinding station 41 and in the second unwinding station 42.

[66] The initial portion of each threadlike metal material 2, 2' is inserted in the respective inlet section of the insertion device 6, in order to be ready for a subsequent feeding to the drawing and straightening unit 3 after having been introduced manually or automatically.

[67] The drawing and straightening unit 3 is actuated and therefore the threadlike metal material, for example the first threadlike metal material 2, is fed along the feeding direction A.

[68] When the first reel 2 is exhausting, for example when the terminal end 21 is unwound by the first reel 5, the detection means 9 or the operator himself detect this circumstance.

[69] The drawing and straightening unit 3 is stopped by the control unit, if provided, or for example by the operator, and the cutting means 8 operated in the interposed position, to separate the end portion 20 from the remaining material. The latter is intended to advance along the feeding direction A to be processed or discarded in whole or in part.

[70] Following the intervention of the cutting means 8, the end portion 20 is separated, but remains gripped by the insertion device 6 (see Figure 1 c) and has an extension suitable for joining, in the position of optimum joining U at the respective unwinding station, the terminal end 21 at the initial end of the reel 5.

[71] Advantageously, it is also possible to provide for an operation of changing of the threadlike metal material, i.e. that the inlet section of the insertion device 6, bearing the second threadlike metal material 2', is aligned with the feeding direction A, to feed the drawing and straightening unit 3 with the respective material (see Figure 1 d).

[72] Finally, the isolation system 7 is preferably deactivated selectively, to allow access to the first unwinding station 41 , in order to replace the first reel 5 (see Figure 1e). In particular, a new first reel 5 is installed in the unwinding station 41. In addition to this, the joining, preferably by welding, of the terminal end 21 of the exhausted reel 5, with an initial portion of the new first reel 5 at the joining position U of said joining, optimal for the execution of the aforementioned union, is carried out, for example with the aid of an operator, within the unwinding station involved and made specifically accessible.

[73] At this point, the first unwinding station 41 is again ready for feeding the drawing and straightening unit 3.

[74] According to a different embodiment, illustrated in Figures 2a to 2d, it is possible to provide that in the apparatus 100 according to the invention the cutting means are made by the same cutting device usually integrated in the drawing and straightening unit 3.

[75] In this case, the cutting section is arranged at a distance X from the insertion device 6.

Therefore, the feeding of the threadlike metal material 2 along the feeding direction A is interrupted when the terminal end 21 is advanced by an advancement stroke, relative to the aforesaid joining position U, substantially of the aforementioned distance X or in any case of a distance not exceeding it. Before making the aforesaid joining between the terminal end 21 and the initial end of a new reel, the drawing and straightening unit 3, or a further drawing unit associated with the insertion device, is operated to retract the threadlike metal material 2 in the retracting direction B opposite to the feeding direction A, in a retraction stroke substantially equal to or not greater than the same distance X, so as to leave the terminal portion 20 separated, gripped by the insertion device 6, and thus to operate the aforementioned joining in the most appropriate position, the aforesaid joining position U, for the operator or for an automatic joining means, in particular robotised.

[76] According to this embodiment it is thus possible to obtain substantially the same advantages by avoiding the need for the presence of a cutting unit 80 or additional equivalent means.

[77] According to a further embodiment of the invention, it is possible to provide that the apparatus comprises, instead of a cutting unit 80, a housing in a position interposed along the feeding direction A between the insertion device 6 and the drawing and straightening unit 3 arranged for the insertion of a cutting device, also manual, suitable for separating the end portion 20 of the threadlike metal material 2, 2' being unwound from a respective reel 5, 5', keeping the terminal portion 20 separate gripped by the same insertion device 6. More precisely, the aforementioned housing is configured to be alternatively closed or made accessible to the insertion of the aforesaid cutting member, for example by providing protection means which may be opened, fixed or mobile, of a physical and/or immaterial type, for example by means of the provision of a protective casing associated with a safety microswitch or a photocell or similar single or multiple means.

[78] Obviously, during the intervention of the operator, the apparatus 1 is arranged in a state of temporary stop in safety, to be reactivated later to resume production, when the operator moves away.

[79] It is understood that the apparatus and the method according to the invention may be used in a completely similar manner also to feed more threadlike materials at a time, for example in two-wire mode.

[80] The operation of the apparatus is similar, for the rest, to what previously described.

[81] In the practical embodiment of the invention, the used materials, as well as the shape and the dimensions, may be modified depending on needs.

[82] Should the technical features mentioned in any claim be followed by reference signs, such reference signs were included strictly with the aim of enhancing the understanding of the claims and hence they shall not be deemed restrictive in any manner whatsoever on the scope of each element identified for exemplifying purposes by such reference signs.