In-line apparatus and method for straightening and cutting metal bars

Abstract

In-line apparatus (10) for straightening and cutting metal bars (50), in particular metal wires, comprising at least one straightening station (11) configured both to feed the metal bars (50) in a direction of feed (D) and also to perform a mechanical straightening action of the metal bars (50), and at least one cutting station (12) disposed downstream of the straightening station (11) and configured to selectively cut the metal bars (50) to a determinate length (L) and deposit them onto a corresponding collection bed (13), the apparatus (10) comprising at least one detection station (14) disposed in operational connection with the cutting station (12) and provided with at least one proximity sensor member (15) configured to cooperate without actual contact with the metal bars (50) and at least detect their presence, in particular at least partly measure a length (L) of their travel, in the direction of feed (D).

Description

[0001] “IN-LINE APPARATUS AND METHOD FOR STRAIGHTENING AND CUTTING METAL BARS”

[0002] FIELD OF THE INVENTION

[0003] The present invention concerns an in-line apparatus and method for straightening and cutting to size bars, either smooth or ribbed, “rebar” type ones, for example to prepare them for subsequent bending or reciprocal welding steps in order to form metal reinforcing or load-bearing structures. In particular, the present invention concerns measuring such metal bars in length, before they are cut to size.

[0004] Here and in the following description and claims, we will generally refer to the straightening and cutting to size of metal bars, although the embodiments described here can be particularly, but not exclusively, applied to the cutting to size of metal wire fed from coils rather than bundles.

[0005] BACKGROUND OF THE INVENTION

[0006] Apparatuses, or lines, for the combined work of straightening and cutting to size of metal bars, or metal wires, for example of the type having a diameter comprised within a sizing range of approximately 3 to approximately 20 millimeters, are known in the art. These bars, or metal wires, can be either smooth or ribbed, such as for example so-called reinforcing bars (rebars), intended for subsequent bending or for reciprocal welding to produce reinforcing cages or meshes, small loadbearing structures or other.

[0007] It is known, in fact, to provide for the bars to be fed starting from bundles or, respectively, from coils, as well as stored at the end of their rolling production cycle, and from here substantially straightened and cut to desired length measurements, as a function of their subsequent industrial uses.

[0008] Henceforth, the generic term metal bar is understood interchangeably, as stated, either as an actual metal bar or as a metal wire, depending on the different types of feed and use.

[0009] In this sense, known apparatuses provide a straightening station which is provided with a drive device configured to feed the metal bar through a series of straightening rollers, so that it is progressively stretched until it reaches a substantially rectilinear conformation. In-line and downstream of the straightening station there is provided a cutting station which, by means of a shear, cuts the straightened metal bar to size, depositing it on a collection bed, from which it is collected for subsequent uses.

[0010] The intervention of the shear is coordinated with the reading of the measurement of the metal bar’s length, by a measuring station which can provide, as a rule, substantially two operating methods, depending on whether the cut occurs “on the fly”, that is, with the bar in motion, or “at intervals”, that is, with the bar stationary.

[0011] In known solutions with the cut of the bar in motion, the measuring station substantially comprises a metric wheel, interposed between the straightening rollers and the shear, which is rotated by the moving metal bar and translates the induced angular speed of rotation into a length of travel of the bar.

[0012] This solution, especially due to the structural rigidity of the metric wheel, can lead to slippages between the passing metal bar and the metric wheel itself, with consequent loss of measurement efficiency, in particular with respect to the crests of the ribbed bars, causing the continuous variation of rotation, resting on the bar.

[0013] In addition, the metric wheel is subject to continuous vibrations and wear, resulting in further progressive inaccuracies in the cutting length.

[0014] In known solutions with the cut of the bar when stationary, the measuring station comprises a detection slider disposed downstream of the shear, in correspondence with the collection bed, at a distance from the shear which is coordinated with the cutting length of the metal bar. The slider comprises a material presence-detection lever, which is moved by the front end of the bar so as to stimulate an electrical activation sensor of the shear.

[0015] Although this type of measurement can be more precise than the metric wheel, it still requires stopping the bar before the cut is performed, resulting in general production slowdowns. In addition, the position of the slider with respect to the shear has to be adjusted (manually or in motorized form) whenever there is a variation in the cutting length, requiring consequent production stops for set-up, with the use of specialized personnel. This set-up operation requires, downstream, carrying out some test cuts outside of the production cycle, so as to check the correctness of the slider’s position, with consequent production rejects and further production loss of the known apparatus.

[0016] There is therefore the need to perfect an in-line apparatus and method for straightening and cutting metal bars that can overcome at least one of the disadvantages of the state of the art.

[0017] To do this, it is necessary to solve the technical problem of accurately and repeatably measuring the length of the bars while maintaining high production standards of the apparatus.

[0018] In particular, one purpose of the present invention is to provide an in-line apparatus and method for straightening and cutting metal bars that allow to cut the bars to length, guaranteeing the accuracy and repeatability of the cut performed, essentially without requiring manual set-up steps or production downtime, even in the event of variations in the length of the cut.

[0019] Another purpose of the present invention is to provide an apparatus whose measuring station is substantially not subject to vibrations and wear, thus preventing any inaccurate measurements of the cutting length.

[0020] 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.

[0021] SUMMARY OF THE INVENTION

[0022] 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.

[0023] In accordance with the above purposes and to solve the technical problem described above in a new and original way, also achieving considerable advantages compared to the state of the prior art, an in-line apparatus according to the present invention is applied to straighten and cut metal bars, which can be either smooth or ribbed, such as for example those known as reinforcing bars (rebars). For descriptive purposes only, these metal bars can have a diameter comprised within a sizing range of approximately 3 to approximately 20 millimeters.

[0024] The apparatus according to the present invention substantially comprises at least one straightening station, which is configured both to feed the metal bars in a direction of feed and also to perform a mechanical straightening action of the metal bars, for example by means of a progressive localized yield created by the action of specific straightening rollers. The apparatus according to the present invention also comprises at least one cutting station, for example provided with a cutting shear, which is disposed downstream of the straightening station with respect to the direction of feed and is configured to selectively cut the metal bars in length and deposit them onto a corresponding collection bed, the latter provided in-line with the cutting station.

[0025] In this way, the metal bars fed into the apparatus according to the present invention are deposited on the collection bed in a substantially straightened condition and cut to a desired size, so as to be suitable for subsequent bending or reciprocal welding steps in order to create reinforcing cages or meshes, small loadbearing structures or other.

[0026] In accordance with one aspect of the present invention, the apparatus comprises at least one detection station, which is disposed in operational connection with the cutting station and is provided with at least one proximity sensor member. The latter is configured to cooperate without actual contact with the metal bars and at least detect their presence, that is, at least partly measure a length of their travel in the direction of feed.

[0027] The solution according to the present invention therefore gives the option of measuring the length of the metal bars advancing in the direction of feed, substantially without direct contact with the metal bars themselves, being able to cut the latter to measure “on-the-fly”, to the benefit of the overall production times and costs of the apparatus according to the present invention.

[0028] This solution according to the present invention allows to carry out a precise and repeatable measurement of the length of the bars while maintaining high production standards of the apparatus. In fact, by avoiding any direct contact with the metal bars, the measuring station’s members are not subjected to any reciprocal slippages with the bars themselves, nor to vibrations and wear, thus guaranteeing the accuracy and repeatability of the cut performed, substantially without requiring manual set-up steps or production downtime, even in the event of variations in the cutting length.

[0029] In fact, contactless detection is essentially free of any positioning constraints, since it does not require the positioning of members or elements that directly contact the metal bars, and can thus be installed substantially at any detection point in the direction of feed.

[0030] In accordance with another aspect of the present invention, the proximity sensor member can comprise an optometric meter, for example laser technology type meters, which is advantageously interposed between the straightening station and the cutting station with respect to the direction of feed. The laser optometric meter is configured to measure without contact the length of travel of the metal bar in the direction of feed and, once a determinate length has been detected, make the cutting station cut the metal bar to size.

[0031] In accordance with another aspect of the present invention, the proximity sensor member can comprise a plurality of optometric detectors, such as for example optical sensors, for example photocells, which are disposed at a determinate pitch in the direction of feed downstream of the cutting station and configured to detect without contact the presence, or the passage, of the metal bars, and from there calculate a determinate length of travel of the metal bars in the direction of feed in order to activate the cutting station to cut the metal bars to size.

[0032] In this solution, the proximity sensor member advantageously also comprises a transducer member, which is operationally connected to the straightening station and is configured to translate the speed of rotation of the operating parts thereof in order to determine, in terms of length, the travel of the metal bars in the direction of feed.

[0033] In this way, through an interpolation of the presence data detected by the optical sensors and the indirect measurement performed by the transducer member, it is possible to obtain, with an acceptable margin of error, the length of travel of the metal bar, in order to command the cutting to size thereof.

[0034] In some preferred embodiments of the solution according to the present invention, the size of the pitch at which the optometric sensors are disposed is comprised between approximately one meter and approximately three meters, advantageously it is approximately one and a half meters, and the optometric sensors can be disposed along a support profile of the collection bed, possibly in an adjustable manner, so as to deliberately vary the pitch, for example, as a function of the cutting lengths of the metal bars, as required.

[0035] In accordance with a further aspect of the present invention, the detection station comprises at least one processing unit, which is electronically connected at least to the proximity sensor member and to the cutting station, and is configured to process the data detected by the proximity sensor member and command the drive of the cutting station, when a determinate length of travel of the metal bars in the direction of feed has been reached.

[0036] Other embodiments described here concern a method for straightening and cutting metal bars, comprising a straightening step which provides both to feed the metal bars in a direction of feed and also to perform a mechanical straightening action of the metal bars, and at least one cutting step downstream of the straightening step to selectively cut the metal bars to a determinate length and deposit them on a corresponding collection bed.

[0037] In some embodiments, the above mentioned method comprises a detection step performed in operational connection with the cutting step, in which at least one proximity sensor member is made to cooperate without actual contact with the metal bars in order to at least detect their presence, in particular to at least partly measure a length of their travel, in the direction of feed.

[0038] DESCRIPTION OF THE DRAWINGS

[0039] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

[0040] - fig. 1 shows a schematic lateral view of a first operating step of a first embodiment of an in-line apparatus for straightening and cutting metal bars, in particular metal wires, according to the present invention;

[0041] - fig. 2 shows a schematic lateral view of a second operating step of the embodiment of the apparatus of fig. 1 ;

[0042] - fig. 3 shows a schematic lateral view of a first operating step of a second embodiment of an in-line apparatus for straightening and cutting metal bars, in particular metal wires, according to the present invention; and

[0043] - fig. 4 shows a schematic lateral view of a second operating step of the embodiment of the apparatus of fig. 3.

[0044] 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.

[0045] 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.

[0046] DESCRIPTION OF SOME EMBODIMENTS

[0047] The attached drawings are used to describe some embodiments of an in-line apparatus 10 and method configured to process a plurality of metal bars, in particular to carry out straightening and cutting thereof, in this specific case metal wires 50, in a number even greater than one at a time, coming from bundles or coils, of a substantially known type and not shown. The metal wires 50 are generally fed in a direction of feed D in the apparatus 10 according to the present invention, and are subjected to a straightening and a cutting to size to make pieces 55 of a desired length L, in order to prepare them for subsequent uses, for example bending and / or welding, to produce reinforcing or structural components.

[0048] By way of example only, the metal wires 50 fed to the apparatus 10 according to the present invention can be, indifferently, either smooth or ribbed, such as for example so-called reinforcing bars (rebars), and can have a diameter comprised within a sizing range of approximately 3 to approximately 20 millimeters. The cutting length L, on the other hand, is chosen according to the requirements of subsequent uses and can vary in size in the order of meters, for example up to a maximum of approximately sixteen meters.

[0049] In general, the apparatus 10 according to the present invention comprises, inline with each other with respect to the direction of feed D, a straightening station 11 and a cutting station 12 with which there is associated, downstream, a bed 13 for collecting the pieces 55.

[0050] The apparatus 10 according to the present invention also comprises a detection station 14 which, as we will see below, is disposed in operational connection with the cutting station 12 and is provided with a generic proximity sensor member 15 which is, in turn, configured to cooperate, without actual contact, with the metal wires 50 and detect their presence, that is, at least partly measure their length L, in the direction of feed D.

[0051] The straightening station 11, from an operational point of view, substantially comprises one or more roller drive units 16, in this specific case two, disposed at inlet into and, respectively, at outlet from the straightening station 11 itself. Each drive unit 16 pressure contacts the metal wires 50 with its rollers and feeds them at a desired speed in the direction of feed D. The straightening station 11 also comprises a straightening unit 17, for example with rollers, interposed between the two drive units 16, in which the metal wires 50 are fed so as to be progressively stretched until they reach a substantially rectilinear conformation, or in any case a conformation sufficiently straightened in relation to the subsequent purposes of use.

[0052] The cutting station 13 substantially comprises a shear 18 disposed downstream of the second of the two drive units 16 of the straightening station 11 and configured to selectively cut the metal wires 50 and define the pieces 55 of a desired length L that are deposited, or unloaded, on the collection bed 13.

[0053] In the embodiment shown in figs. 1 and 2, the proximity sensor member 15 comprises an optometric meter, or laser meter 19, which is advantageously interposed between the second of the two drive units 16 of the straightening station 11 and the shear 18 of the cutting station 12.

[0054] The laser meter 19 is disposed at an expected operating distance from the metal wires 50 being fed, and is conformed to measure without contact the length L of the travel of the metal wires 50 in the direction of feed D.

[0055] According to the invention, the detection station 14 also comprises a processing unit 20, which is electronically connected both to the proximity sensor member 15, in this specific case to the laser meter 19, and also to the cutting station 12.

[0056] The processing unit 20 is programmed to receive the measurement data coming from the laser meter 19 (fig. 1) and, as a function of the length L parameters set, activate the shear 18 when the length L has been reached (fig. 2), so as to progressively generate the pieces 55.

[0057] In the embodiment shown in figs. 3 and 4, the proximity sensor member 15 comprises both a plurality of optometric detectors, or optical sensors 21, for example photocells, and also a transducer member, for example an encoder 22.

[0058] The optical sensors 21 are positioned spaced apart from each other by a certain pitch P in the direction of feed D, starting from the shear 18 of the cutting station 12. In particular, each optical sensor 21 is mounted on a support profile 23 of the collection bed 13, which support profile 23 extends substantially parallel to the direction of feed D. In addition, each optical sensor 21 is configured to visually detect, always without contact, the presence, that is, the travel, of the metal wires 50 in the direction of feed D.

[0059] According to some operating variants, induction sensors can be provided instead of the optical sensors 21, or in any case other types of sensors capable of detecting the presence, that is, the travel, of the metal wires 50, always without direct contact therewith.

[0060] Although not specifically shown in the attached drawings, the assembly of each optical sensor 21 onto the support profile 23 is such as to allow to selectively adjust the pitch P, as a function of specific optimizations for detecting the presence of the metal wires 50, also in relation to the length L provided for the pieces 55.

[0061] Generally, the pitch P can be chosen with a size comprised between approximately one meter and approximately three meters, advantageously it is approximately one and a half meters, as a function of the lengths L of the pieces 55 normally required by the market. It is clear that, as the lengths L required by the market vary, the pitch P can also be chosen with sizes that differ from those indicated here by way of example.

[0062] In this embodiment, the encoder 22 is operationally connected to at least one roller of one of the two drive units 16 of the straightening station 11, and is configured to measure the number of revolutions “n” of the corresponding roller in the unit of time, so as to derive the angular speed of rotation thereof at the passage of the metal wires 50, in the direction of feed D.

[0063] Also in this embodiment, the detection station 14 comprises a processing unit 20 which is electronically connected both to the proximity sensor member 15, in this specific case to the optical sensors 21 and to the encoder 22, and also to the cutting station 12.

[0064] The processing unit 20 is programmed to receive both the presence or absence data of the metal wires 50 coming from the optical sensors 21, and also the speed of rotation data coming from the encoder 22 (fig. 3).

[0065] As a function of the length L parameters set, the processing unit 20 implements the data received and identifies through combined calculation the actual length of the travel of the metal wires 50.

[0066] Briefly, as a function of how many optical sensors 21 detect the presence of the metal wires 50, for example the first two, knowing the value of the pitch P, the processing unit 20 obtains a first travel value which, subtracted from the nominal value of the length L of the pieces 55, determines a differential value A. At this point, based on the angular speed obtained from the number of revolutions “n” detected by the encoder 22 in real time, it is possible to calculate a travel space of the metal wires 50 in the direction of feed D. When this calculated travel space coincides with the differential A, the processing unit 20 activates the shear 18 (fig.

[0067] 2), so as to progressively generate the pieces 55 of a desired length L.

[0068] It is clear that modifications and / or additions of parts may be made to the apparatus 10 as described heretofore, without thereby 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 apparatus for straightening and cutting metal bars, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby. In the following claims, the sole purpose of the references in brackets is to facilitate their reading and they must not be considered as restrictive factors with regard to the field of protection defined by the claims.

Claims

CLAIMS1. In-line apparatus (10) for straightening and cutting metal bars (50), in particular metal wires, comprising at least one straightening station (11) configured both to feed said metal bars (50) in a direction of feed (D) and also to perform a mechanical straightening action of said metal bars (50), and at least one cutting station (12) disposed downstream of said straightening station (11) and configured to selectively cut said metal bars (50) to a determinate length (L) and deposit them, or unload them, onto a corresponding collection bed (13), characterized in that it comprises at least one detection station (14) disposed in operational connection with said cutting station (12) and provided with at least one proximity sensor member (15) configured to cooperate without actual contact with said metal bars (50) and at least detect their presence, in particular at least partly measure a length (L) of their travel, in said direction of feed (D).

2. Apparatus (10) as in claim 1, characterized in that said proximity sensor member (15) comprises an optometric meter (19), in particular a laser meter, interposed between said straightening station (11) and said cutting station (12) and conformed to measure without contact the length (L) of travel of said metal bars (50) in said direction of feed (D).

3. Apparatus (10) as in claim 1, characterized in that said proximity sensor member (15) comprises a plurality of optometric detectors (21), in particular optical sensors, disposed at a determinate pitch (P) from each other in said direction of feed (D) downstream of said cutting station (12) and configured to detect without contact the presence, or the passage, of said metal bars (50).

4. Apparatus (10) as in claim 3, wherein said straightening station (11) comprises at least one roller drive unit (16) configured to feed said metal bars (50) in said direction of feed (D), characterized in that said proximity sensor member (15) comprises at least one transducer member (22) operatively connected to said drive unit (16) and configured to detect a speed of rotation (n) of its rollers and to determine, in terms of length, the travel of said metal bars (50) in the direction of feed (D).

5. Apparatus (10) as in claim 3 or 4, characterized in that said determinate pitch (P) of disposition of said plurality of optometric detectors (21) has a size comprised between approximately one meter and approximately three meters.

6. Apparatus (10) as in claim 3, 4 or 5, characterized in that said determinate pitch (P) has a size comprised between one meter and three meters.

7. Apparatus (10) as in one or the other of the previous claims from 3 onward, characterized in that said plurality of optometric detectors (21) are disposed along said collection bed (13).

8. Apparatus (10) as in claim 7, characterized in that said collection bed (13) comprises at least one support profile (23) configured to support said plurality of optometric detectors (21).

9. Apparatus (10) as in one or other of the previous claims, characterized in that said detection station (14) comprises at least one processing unit (20) electronically connected at least to said proximity sensor member (15) and to said cutting station (12) and configured to process the data detected by said proximity sensor member (15) and to command the drive of said cutting station (12), when a determinate length (L) of travel of said metal bars (50) in said direction of feed (D) has been reached.

10. Method for straightening and cutting metal bars (50), in particular metal wires, comprising a straightening step which provides both to feed said metal bars (50) in a direction of feed (D) and also to perform a mechanical straightening action of said metal bars (50), and at least one cutting step downstream of said straightening step to selectively cut said metal bars (50) to a determinate length (L) and deposit them on a corresponding collection bed (13), characterized in that said method comprises a detection step performed in operational connection with said cutting step in which at least one proximity sensor member (15) is made to cooperate without actual contact with said metal bars (50) in order to at least detect their presence, in particular to at least partly measure a length (L) of their travel, in said direction of feed (D).

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