FIELD OF APPLICATION

The present invention relates to an apparatus and a relative method for bending oblong metal products to obtain, preferably but not exclusively, brackets having a three-dimensional geometry, i.e., with at least one portion bent on an orthogonal plane, or in any case angled, with respect to the bending plane of the other portions. The oblong metal products can be bars, rods, metal wires, which can be made available either as pre-cut segments or in continuous form wound on a reel and cut to the desired length before or at the end of the processing.

BACKGROUND ART

Apparatuses are known for bending metal products, also called brackets, configured to bend a bar, a rod, a metal wire or other oblong metal product, so as to obtain brackets for example for making reinforcement cages. Such brackets can be two-dimensional, i.e., where the sides of the bracket lie on the same plane, or three-dimensional, i.e., where at least one side of the bracket lies on a different plane from that on which the other sides of the latter extend. An example of a bending device in which there are multiple bending units which perform bends on a single plane is described in AT 406 744.

Apparatuses for the three-dimensional bending of metal products are known which comprise a bar movement unit or device, a cutting unit and a single bending unit which bends both on a first bending plane, to define the two-dimensional shaping of the bracket, and on further bending planes, angled with respect to the first bending plane, to define the three-dimensional shaping of the bracket.

The bending unit is mounted on a fixed worktop and comprises a rotating spindle provided centrally with a single contrast pin and radially with a single bending element.

The bending element is rotatable around the contrast pin along a rotation axis orthogonal to the fixed worktop, so that the segment of metal product which is interposed between the bending element and the contrast pin is bent around the latter.

The bar movement device is configured not only to advance the metal product along a working direction, but also to rotate the latter around its extension axis so that the same bending unit can perform bends on inclined planes with respect to the bending plane on which a first bend is extended. In fact, rotating the metal product after a bend has been made, allows the bending unit to perform a further bend which extends on a different plane with respect to that of extension of the previous bend.

A drawback of such known apparatuses is that during the rotation of the metal product, the bends already made remain cantilevered above the worktop, whereby the metal product can undergo deformations under the action of its own weight. As a result, the bends already made can undergo a deformation and in the worst cases the bracket made is not suitable for its use.

A further drawback of such known apparatuses is that the bar movement device is subject to considerable stresses, especially when it rotates the metal product which can undergo twists and deformations which can compromise the mechanical properties of the bracket made.

A further drawback of such known apparatuses is that they do not allow multiradius bends to be made on the same product being processed. Accordingly, the bending unit must be, from time to time, equipped with the rotating spindle having the desired bending radii. This results in a process interruption, a dilation of the production times and costs as well as positioning errors due to the re-equipping of the bending unit.

Another drawback of such known apparatuses is that they are not fully automated and therefore can be dangerous because they require the presence of one or more operators for the control of the process, for example for positioning the metal product, or for its temporary support and its evacuation.

Therefore, there is a need to improve an apparatus and a relative method for bending oblong metal products, which can overcome at least one of the drawbacks of the prior art.

It is therefore necessary to solve the technical problem of making a series of bends on an oblong metal product on different planes so that such oblong metal product is overall resting on at least one of the worktops where the bends are performed.

In particular, an object of the present invention is to provide an apparatus and a relative method for bending oblong metal products to obtain brackets having a three-dimensional conformation with high precision and quality bends.

Another object of the present invention is to provide an apparatus for bending oblong metal products in which the brackets can be made with multi-radius bends without having to re-equip the machine.

A further object of the present invention is to provide an apparatus for bending oblong metal products in which the bar movement device is not subject to excessive stresses when moving the metal products being processed.

Another object of the present invention is to provide an apparatus for bending oblong metal products which is particularly simple and allows to obtain brackets with a planar or three-dimensional conformation with a wide variety of shapes.

A further object of the present invention is to provide an apparatus for bending oblong metal products which is fully automated.

The Applicant has studied, tested and realized the present invention to overcome the drawbacks of the prior art, and to obtain the above as well as further objects and benefits.

DISCLOSURE OF THE INVENTION

The present invention is expressed and characterized in the independent claims. The dependent claims show other features of the present invention or variants of the main solution proposed.

In accordance with the aforesaid objects and to solve the aforesaid technical problem in a new and original manner, also obtaining considerable advantages with respect to the prior art, an apparatus according to the present invention for bending oblong metal products comprises a movement device, configured to move said oblong metal products along a feed axis, and a first bending unit provided with one or more first bending devices, distinct from each other and configured to bend one or more of said oblong metal products at a time on a same first bending plane with different bending radii.

According to an aspect of the present invention, said apparatus comprises at least a second bending unit disposed upstream of said first bending unit, distinct from the latter, and provided with one or more second bending devices distinct from each other and configured to bend said oblong metal products on a same second bending plane, inclined with respect to said first bending plane, with different bending radii.

In accordance with another aspect of the present invention, said first bending plane is horizontal. Furthermore, said second bending plane is orthogonal with respect to said first bending plane.

In accordance with another aspect of the present invention, at least said second bending unit is configured to be orientable with respect to said first bending unit in order to adjust the inclination of said second bending plane with respect to said first bending plane, both when the machine is stopped and also on the fly.

In accordance with another aspect of the present invention, said first and second bending units are respectively provided with a first and a second support plate, which define said first and second bending planes and on which said first and second bending devices are installed in a fixed manner. Said first and second support plates are respectively movable along a first and a second direction of adjustment, which are inclined with respect to each other and orthogonal to said feed axis in order to respectively align one of said first and second bending devices with said feed axis.

In accordance with another aspect of the present invention, said apparatus comprises a fixed support plane, disposed horizontal and having two opposite and parallel leading edges. Said first support plate is coplanar to said support plane and installed in an aperture made on the latter. Said second support plate is orthogonal to said support plane and installed externally with respect to the perimeter thereof, in correspondence with one of said leading edges.

In accordance with another aspect of the present invention, said first and second bending units are provided with respective holding devices, disposed upstream and/or downstream of said first and second bending devices, and retractably mobile in order to temporarily hold said one or more oblong metal products during the execution of the bends.

According to an embodiment variant, said apparatus also comprises a third bending unit similar to the first two, disposed downstream of said first bending unit and inclined with respect to the latter in order to bend said one or more oblong metal products on a third bending plane, angled with respect to said first bending plane.

According to another aspect of the present invention, said apparatus comprises a fixed guide member with which said movement device is slidingly associated in order to take said one or more oblong metal products from a bar loading zone towards said first and second bending units. Said movement device comprising an arm sliding on said guide member which is terminally provided with a gripping head configured to temporarily hold said one or more oblong metal products.

The present invention also relates to a method for bending oblong metal products and comprises:

- a movement step, in which said movement device moves one or more of said oblong metal products forward or backward at a time along the feed axis,

- a first bending step, in which said first bending unit performs one or more bends by means of one or more first bending devices, distinct from each other on the same first bending plane with different bending radii.

In accordance with an aspect of the present invention, the method also comprises a second bending step, in which said second bending unit performs one or more bends by means of said one or more second bending devices, distinct from each other, on a same second bending plane with different bending radii.

ILLUSTRATION OF THE DRAWINGS

These and other aspects, features and advantages of the present invention will become clear from the disclosure of some embodiments, provided by way of nonlimiting example, with reference to the accompanying drawings in which:

- figure 1 is an axonometric view of an apparatus for bending oblong metal products, according to the present invention;

- figure 2 is an enlarged view of part of figure 1 ;

- figure 3 is an embodiment variant of figure 2 in which the second bending unit comprises three bending devices;

- figure 4 is an embodiment variant of figure 1 in which a third bending unit is also present.

It should be noted that, in the present disclosure, the phraseology and terminology used, as well as the figures in the accompanying drawings, even as disclosed, have the sole purpose of illustrating and explaining the present invention, since their function is illustrative and not limited to the invention itself, the scope of protection thereof being defined by the claims.

To facilitate understanding, identical reference numbers have been used, where possible, to identify identical common elements in the figures. It should be noted that elements and features of an embodiment can be conveniently combined or incorporated into other embodiments without further clarification.

DESCRIPTION OF SOME EMBODIMENTS OF THE PRESENT INVENTION

With reference to figure 1, an apparatus 10 according to the present invention, is configured to bend an oblong metal product, or more than one at a time, in this case one or more metal bars 100, so as to make brackets 200 or other reinforcement shapes for construction having a three-dimensional geometry. The bars 100 can have a length comprised between about 6 m and about 24 m and diameters comprised between about 10 mm and about 40 mm.

The apparatus 10 comprises a fixed structure 11 having a support plane 12, disposed substantially horizontal with respect to an installation surface of the apparatus 10. However, it is not excluded that the support plane 12 can also be inclined with respect to such an installation surface, for example to facilitate the evacuation of the brackets 200 made.

The support plane 12 can comprise or be formed by a metal sheet or plate having a certain thickness and a substantially rectangular shape.

The support plane 12 has two longer lateral sides 13, 14 opposite and parallel to each other and two shorter leading edges 15, 16, also opposite and parallel to each other. The length of the lateral sides 13, 14 is consistent with the maximum length of the bars 100 to be processed.

The apparatus 10 comprises a bar loading zone LZ, where a feeding device is present, substantially of a known type and not illustrated, configured to feed bars 100 in the form of pre-cut segments or continuously wound on a reel and cut to the desired length, and a bar unloading zone UZ where a plane or a wheeled container can be present, configured to receive the shaped bars 100, i.e., the brackets 200.

The bar loading zone LZ is disposed at one or both of the leading edges 15, 16 of the support plane 12, while the bar unloading zone DZ is disposed at one or both of the lateral sides 13, 14 of the support plane 12.

The apparatus 10 comprises a movement device 17 configured to move the bars 100 along a feed axis X, a first bending unit 18 configured to bend the bars 100 on a first bending plane Pl, and at least a second bending unit 19 disposed upstream of the first bending unit 18, with respect to the direction of arrival of the bars 100 along the feed axis X, and inclined with respect to the latter to perform bends on a second bending plane P2 which, in the present case, is substantially orthogonal to the first bending plane Pl .

The second bending unit 19 is disposed between the loading zone LZ and the first bending unit 18. Accordingly, the moved bars 100 first encounter the second bending unit 19 and then the first bending unit 18. However, the order in which the two bending units 18, 19 work depends on the bends which are intended to be made on the bar 100.

The first and second bending unit 18, 19 are disposed in a fixed position with respect to each other.

According to a variant, at least the second bending unit 19 can be orientable with respect to the first bending unit 18 so as to adjust the inclination of the second bending plane P2 with respect to the first bending plane P 1 , both when the machine is stopped and on the fly. In this case, the bending plane P2 does not have a fixed angle with respect to the first bending plane P2, but is orientable with respect to the latter.

According to a possible embodiment illustrated in figure 4, the apparatus 10 can also comprise a third bending unit 22, similar to the first two, disposed downstream of the first bending unit 18 and inclined with respect to the latter to make bends on a third bending plane P3. The bending plane P3 can be parallel to the second bending plane P2 or have a different inclination. In this embodiment, a further loading zone can be present also in correspondence with the leading edge 16 and the apparatus can work with two separate inputs of metal products, for example one from the reel and one from pre-cut segments.

With reference to figures 2 and 3, the first bending unit 18 and the second bending unit 19 respectively comprise one or more first bending devices 20 and one or more second bending devices 21 respectively aligned along a first adjustment axis T1 and along a second adjustment axis T2 both transverse, in this case orthogonal, with respect to the feed axis X and with respect to each other.

In the embodiment of figures 1 and 2, the first bending unit 18 is provided with three first bending devices 20 while the second bending unit 19 is provided with a single second bending device 21.

In the embodiment of figure 3, also the second bending unit 19 is provided with three second bending devices 21; embodiments where the number of bending devices 20, 21 is different from that depicted in the figures are not excluded.

Each bending device 20, 21 is provided with a central contrast pin 23, 24, respectively, a bending spindle or support 25, 26 mounted coaxial and rotatable with respect to the contrast pin 23, 24, and a bending pin 27, 28 mounted peripherally on said spindle 25, 26.

Said contrast pins 23, 24 have a substantially cylindrical shape; it is not excluded that in different operating solutions contrast pins 23, 24 can be provided double, shaped or of other shapes and sizes.

Each bending pin 27, 28 is selectively rotatable clockwise, or counterclockwise, around the corresponding contrast pin 23, 24 so as to make the desired bend on the bar 100, in one direction or the other, in cooperation with the respective contrast pin 23, 24.

Said contrast pins 23, 24 of distinct bending devices 20, 21 of the same bending unit 18, 19 have different dimensions from each other so that each bending device 20, 21 is capable of making bends with a different radius of curvature. In the event of cylindrical contrast pins 23, 24, the different dimensions correspond to the radii of curvature of the lateral surfaces thereof.

The first bending unit 18 is provided with a first support plate 30 which substantially defines the first bending plane Pl and on which the first bending devices 20 are installed in a fixed manner. Similarly, the second bending unit 19 is provided with a second support plate 31 which substantially defines the second bending plane P2 and on which the second bending devices 20 are installed in a fixed manner.

The first support plate 30 is substantially coplanar to the support plane 12 and is installed through in an aperture 32 made on the surface delimited by the lateral sides 13, 14 and the leading edges 15, 16 of the support plane 12.

The second support plate 31 is substantially orthogonal to the support plane 12 and is installed externally with respect to the perimeter thereof, in correspondence with one of the shorter leading edges 15, 16 on which a recess, or step, is made.

In the present embodiment, the support plates 30, 31 have a substantially rectangular shape and the bending devices 20, 21 are aligned parallel to the longer edges of the respective support plates 30, 31. The support plates 30, 31 are selectively movable along the corresponding adjustment axis Tl, T2 so as to allow the alignment of one of the bending devices 20, 21 with respect to the feed direction X of the bars 100.

The second bending unit 19 comprises a fixed structure 33 on which two lateral guides 34 are obtained on which the second support plate 31 is slidingly mounted. The foregoing applies, in a similar manner, also to the first bending unit 18.

In an alternative embodiment, the support plates 30, 31 can have a circular shape and the positioning of the desired bending device 20, 21 is performed by the rotation thereof.

Each bending device 20, 21 is retractably mobile in a direction orthogonal to the corresponding bending plane Pl, P2, in a manner known per se and therefore not described in detail. Thereby, the bending devices 20, 21 not concerned with the bending being performed can be positioned so as not to interfere with the bar 100 being processed, as can be seen in figures 2 and 3.

Each bending unit 18, 19 is also provided with respective holding devices 35, 36 disposed at least upstream of the bending devices 20, 21, but advantageously also downstream, and configured to temporarily hold the bars 100 during the execution of the bends to avoid undesired bending and deformation. The activation of the downstream or upstream holding device 35, 36 depends on the end of the bar 100 where the bend is to be made.

The holding devices 35, 36 are aligned along the feed axis X and are retractably mobile in a direction orthogonal to the corresponding bending plane Pl, P2, in a manner known per se and not described herein. Said devices 35, 36 which are not activated during the execution of a specific bend are therefore preferably disposed below the corresponding bending plane Pl, P2.

The apparatus 10 comprises a fixed guide member 37, which in this case is a beam 38, disposed above the support plane 12 and having an extension along a feed axis X. The beam 38 is substantially parallel to the lateral sides 14, 15 of said plane 12.

The movement device 17 has an arm 39 sliding, with respect to one end thereof, on the beam 38 and is terminally provided with a gripping head 40 configured to temporarily hold the bars 100 and selectively movable along a gripping direction Z substantially orthogonal to the feed axis X to lift them with respect to the support plane 12.

The support plane 12 is equipped with evacuation devices 41, for example chains, configured to convey the shaped bars 100 at the end of the bending operations along an evacuation direction orthogonal to the feed axis X of the bars 100. The chains are disposed parallel to the leading edges 15, 16 of the support plane 12 so that the shaped bars 100 are unloaded towards the unloading zone UZ.

The operation of the apparatus 10 described so far, which corresponds to the method according to the present invention, comprises the following steps:

- a movement step, in which the movement device 17 moves one or more bars 100 forward or backward at a time along the feed axis X,

- a first bending step, in which the first bending unit 18 performs one or more bends by means of the one or more first bending devices 20, distinct from each other on the same first bending plane Pl with different bending radii.

The method also comprises at least a second bending step, in which the second bending unit 19 performs one or more bends by means of one or more second bending devices 21, distinct from each other on said second bending plane P2 with different bending radii.

During the execution of the bends, i.e., during the first and second bending step, the bars 100 are only made to translate along the feed axis X, in one direction or the other. The bars 100 are not rotated around their own axis.

The first bending step can also occur after the second bending step depending on the bend made on the bar 100.

It is clear that modifications and/or additions of parts may be made to the apparatus 10 and to the method disclosed herein, without departing from the 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 skilled in the art will be able to make many other equivalent forms of an apparatus and method for bending oblong metal products having the features expressed in the claims and therefore all of which falling within the scope of protection defined thereby.

In the following claims, the references in parentheses have the sole purpose of facilitating reading and must not be considered as limiting factors of the scope of protection defined by the claims themselves.