Patent Description:
In particular, the drawing and straightening unit according to the present invention is applied, preferentially, but not restrictively, to machines that simultaneously work two bars, round pieces or wires, at a time, carrying out a uniform, coordinated and simultaneous feed.

Bending/shaping machines, or stirrup-making machines, are known, which are fed with elongated metal products, such as metal wires from a roll or pre-cut bars, to make reinforcement products for the building trade.

Both metal products fed from a roll, and also those in pre-cut bars are generally obtained at the end of the hot rolling cycle and normally have a series of ribs on the outside, to improve the conditions of adhesion to the cement during use.

Furthermore, in the case of metal products stored in rolls, a straightening operation must be performed before they are used, in order to eliminate the loops, bends and internal tensions present in the product. Generally, the straightening operation takes place upstream of the drawing operation.

Typically, bending/shaping machines are fed with one or more metal products at a time in order to optimize the productivity of the machine.

The machines are fed through drawing and straightening units which normally comprise a motorized roller provided with one or more circular grooves, in which the metal products to be fed are disposed, and one or more contrast rollers, opposite the motorized roller with respect to the metal products.

Upstream of the drawing and straightening unit there is a feed unit that allows to supply the metal products substantially in line with the axis of feed.

The feed unit can comprise guide apertures with different shapes and/or diameters, through which the metal wire or wires unwound from respective coils pass.

One disadvantage of known drawing and straightening units is that, although the metal products to be drawn are supplied by the feeder substantially already aligned with the axis of feed, they may not be perfectly aligned with the grooves of the motorized roller.

Non-alignment or inaccurate alignment can cause high wear on part of the upper edges of the grooves or of the free surfaces of the motorized roller. The deformation of the grooves, or in any case a widening of the inlet zone, can cause an incorrect positioning of the metal products and an ineffective drawing.

Another disadvantage is that when the diameter of the wire or wires being worked is changed, there is a need to align the apertures in the feed unit with the grooves of the motorized drawing roller. In the state of the art, this entails the need to translate the entire feed unit laterally, involving complex movement and alignment operations.

A known apparatus comprising a drawing and straightening unit is disclosed in <CIT>.

There is therefore a need to perfect a drawing and straightening unit for elongated metal products which can overcome at least one of the disadvantages of the state of the art.

In particular, one purpose of the present invention is to provide such a drawing and straightening unit able to limit wear on the circular grooves of the motorized roller.

Another purpose of the present invention is to provide such a drawing and straightening unit which allows an extremely precise alignment of the metal products to be worked, limiting possible strains and stresses in unforeseen directions.

Another purpose is to perfect a drawing and straightening method which is simple to implement and rapidly allows a precise engagement of the drawing unit with the products being worked.

In accordance with the above purposes, an apparatus for working metal products comprising a drawing and straightening unit for feeding one or more metal products according to claim <NUM> is proposed.

The invention also concern a drawing and straightening method for feeding one or more elongated metal products, according to claim <NUM>.

The embodiments described with reference to the attached drawings concern a drawing and straightening unit <NUM> which is part of an apparatus for working metal products <NUM>.

The drawing and straightening unit <NUM> is suitable, for example, to feed a working machine <NUM>, which can be a bending/shaping machine or a stirrup-making machine, which is fed with at least one elongated metal product P, for example a metal wire or round piece, advantageously two simultaneously.

The metal products P in question are typically contained in rolls or coils, disposed upstream of the apparatus for working bars <NUM>.

The metal products P can be characterized by very different diameters, materials and surface finishes, for example ribs.

This variability of the metal products P is given by the need of the working machine <NUM> to produce a more or less complex range of finished products, for example brackets, suitable for a variety of applications.

According to some embodiments, the drawing and straightening unit <NUM> has at least one first roller <NUM> provided peripherally with a plurality of circular grooves <NUM>, <NUM>, <NUM> inside each of which a respective metal product P to be fed is able to be positioned.

The drawing and straightening unit <NUM> comprises at least one second roller <NUM>, <NUM>, <NUM> opposite the first roller <NUM> with respect to an axis of feed X of the at least one metal product P.

According to some embodiments, the at least one first roller <NUM> is motorized and the at least one second roller <NUM>, <NUM>, <NUM> is idle and is adjustable at least vertically with respect to the first roller <NUM>.

According to the invention, the number of second rollers <NUM>, <NUM>, <NUM> is equal to the number of grooves <NUM>, <NUM>, <NUM> of the first roller <NUM>, so that each second roller <NUM>, <NUM>, <NUM> is aligned with a respective groove <NUM>, <NUM>, <NUM>.

With particular reference to the example described here, the first roller <NUM> is provided with three grooves, in particular an internal groove <NUM>, an external groove <NUM> and a central groove <NUM> made between them.

The grooves <NUM>, <NUM>, <NUM> are circular and have a substantially V-shaped cross section with sizes correlated to the nominal diameter of the metal products P to be fed.

The second rollers comprise a second external roller <NUM>, a second internal roller <NUM> and a second central roller <NUM> disposed between them.

Advantageously, the second rollers <NUM>, <NUM>, <NUM> are configured to rotate independently of each other, in a way that is per se known.

Furthermore, with reference to <FIG>, each second roller <NUM>, <NUM>, <NUM> can advantageously be moved independently toward/away from the first roller <NUM> in order to keep each metal product P correctly positioned inside the respective groove <NUM>, <NUM>, <NUM>.

There can also be provided an overall movement of the second rollers <NUM>, <NUM>, <NUM> with a greater excursion than the excursion of the independent movements, for example to perform an initial approach toward the first roller <NUM>.

Furthermore, the drawing and straightening unit <NUM> can comprise more than one group of second rollers <NUM>, <NUM>, <NUM>.

With reference to <FIG>, the drawing and straightening unit <NUM> comprises two groups of second rollers <NUM>, <NUM>, <NUM> disposed one after the other along the axis of feed X.

The at least one second roller <NUM>, <NUM>, <NUM> can have a smooth peripheral surface, or one provided with circumferential grooves or ridges, as shown in the example of <FIG>, to carry out a more effective flattening of the metal products P.

Upstream of the drawing and straightening unit <NUM> there is a feed unit <NUM> comprising at least one feeder unit <NUM> configured to slidingly support a portion in length of a certain number of metal products P to be supplied to the drawing and straightening unit <NUM>.

The number of metal products P supported by the feed unit <NUM> substantially depends on the range of finished products that the working machine <NUM> fed by the drawing and straightening unit <NUM> has to produce.

According to one aspect of the present invention, the drawing and straightening unit <NUM> is mobile in a direction of adjustment Y transverse with respect to the axis of feed X in order to transversely align one or more of the grooves <NUM>, <NUM>, <NUM> with respective metal products P fed by the feed unit <NUM>.

This solution therefore allows to obtain a precise and defined alignment of the drawing and straightening unit <NUM> with the metal products P at entry, preventing unwanted and ineffective draws, transverse stresses, and excessive wear of the grooves <NUM>, <NUM>, <NUM>, particularly along the edge, or points, of attachment, that is, the points at which the metal products P enter the grooves <NUM>, <NUM>, <NUM>.

According to some embodiments, the apparatus <NUM> comprises a support structure <NUM> with which there are associated at least the drawing and straightening unit <NUM> and favorably also the feed unit <NUM> and the working machine <NUM>.

The support structure <NUM> can be favorably configured to support the drawing and straightening unit <NUM> and the feed unit <NUM> in an inclined position with respect to the plane, for example the floor, where the support structure <NUM> is disposed resting, see for example <FIG>.

For example, the drawing and straightening unit <NUM> and the feed unit <NUM> can be disposed on a common lying plane, or on parallel lying planes, equally inclined with respect to the floor plane.

The feeder body <NUM> is provided with guide apertures <NUM>, <NUM>, <NUM> through which respective metal products P to be supplied to the drawing and straightening unit <NUM> are supported slidingly.

The feed unit <NUM>, in particular the feeder body <NUM>, can be disposed in such a way that at least the through axis of one of the guide apertures <NUM>, <NUM>, <NUM> that supports the metal product P to be fed is coplanar and parallel with an initial segment of the axis of feed X.

The axis of feed X can coincide on each occasion with the through axis of one of the guide apertures <NUM>, <NUM>, <NUM>.

In the case of two guide apertures, for example, <NUM>, <NUM> coupled for the simultaneous advance of two metal products P, there can be defined two axes of feed X parallel to each other, distinct and aligned with the axes of the same guide apertures <NUM>, <NUM>.

The feed unit <NUM> can comprise a pair of engagement rollers <NUM> disposed between the feeder body <NUM> and the drawing and straightening unit <NUM> in order to engage and draw a first segment of metal product P, for example during a format change operation.

The guide apertures <NUM>, <NUM>, <NUM> of the feeder body <NUM> can have a substantially circular shape and a diameter coherent with a maximum transverse size of the metal product P to be fed.

The guide apertures <NUM>, <NUM>, <NUM> are made through the feeder body <NUM> and have respective through axes parallel to each other.

For example, the guide apertures <NUM>, <NUM>, <NUM> are made through from one side of the feeder body <NUM> facing the coil magazine, to an opposite side facing toward the drawing and straightening unit <NUM>, as shown with a dashed line in <FIG>.

The through axes of the guide apertures <NUM>, <NUM>, <NUM> can be coplanar or offset in some way.

With particular reference to <FIG>, an example is described in which the guide apertures <NUM>, <NUM> are coupled and have a substantially identical diameter, allowing the simultaneous support and sliding of two metal products P having the same geometric characteristics, while the guide aperture <NUM> is single and has a larger diameter than the diameter of the guide apertures <NUM>, <NUM>.

Other configurations and dispositions of the guide apertures <NUM>, <NUM>, <NUM> and of possible additional guide apertures are possible.

The drawing and straightening unit <NUM> can be moved in the direction of adjustment Y with an adjustment range coherent with the position of the apertures <NUM>, <NUM>, <NUM>.

In particular, the drawing and straightening unit <NUM> is mobile between a waiting position and a plurality of alignment positions.

Each alignment position is reached by moving the drawing and straightening unit <NUM> in such a way as to transversely align the grooves <NUM>, <NUM>, <NUM> with one or more of the guide apertures <NUM>, <NUM>, <NUM> along the axis or axes of feed X.

The waiting position can be a generic position of the drawing and straightening unit <NUM> which is located between the maximum range position and the minimum range position. For example, the waiting position can be the last alignment position previously reached.

With reference to <FIG>, a possible sequence of movement of the drawing and straightening unit <NUM> is shown by way of example, in which, for simplicity, only the first roller <NUM> and the second rollers <NUM>, <NUM>, <NUM>, and the feeder body <NUM> have been shown.

In a first case, top left of <FIG>, the drawing and straightening unit <NUM> can pass from a waiting position, for example central, to a first alignment position in which the grooves <NUM>, <NUM> are aligned with the guide apertures <NUM>, <NUM> along a pair of axes of feed X. In this case, the working machine <NUM> positioned downstream of the drawing and straightening unit <NUM> is adjusted to work two metal products P simultaneously.

In a second case, at the bottom right of <FIG>, the drawing and straightening unit <NUM> can pass from the waiting position, for example coinciding with the previous alignment position, to a second alignment position where the groove <NUM> is aligned with the guide aperture <NUM> along the axis of feed X, in such a way that the working machine receives a single metal product P having a larger diameter.

Operationally, it is preferable to feed either a pair of identical metal products P with a smaller diameter, or a single metal product P with a larger diameter.

The direction of adjustment Y is substantially orthogonal to the axis of feed X which can be rectilinear, for example immediately at the exit from the feeder body <NUM>, or possibly comprise a curved segment, for example in a zone comprised between the entry section and the exit section of the drawing and straightening unit <NUM>.

In fact, in possible configurations, the drawing and straightening unit <NUM> can also comprise a plurality of yielding rollers <NUM> disposed upstream and downstream of the first roller <NUM> and of the at least one second roller <NUM>, <NUM>, <NUM>, defining with them as a whole a drawing loop that delineates a curve in the axis of feed X.

The direction of adjustment Y is parallel to the axis of rotation of the first roller <NUM> and of the second roller <NUM>, <NUM>, <NUM>.

The drawing and straightening unit <NUM> comprises an assembly defined by a mobile support <NUM> with which the first roller <NUM> and the at least one second roller <NUM>, <NUM>, <NUM> are associated, and the movement means <NUM> are able to move the assembly in an integral way in the direction of adjustment Y.

With reference to <FIG>, the movement means <NUM> can be disposed between the support structure <NUM> and the mobile support <NUM>.

The mobile support <NUM> can be configured as a substantially flat metal plate on the external side of which the first roller <NUM> and the at least one second roller <NUM>, <NUM>, <NUM> are attached, in a way per se known. However, other constructive configurations are not excluded.

The movement means <NUM> can comprise at least one of either a jack, a linear actuator, sliding guides, chain mechanisms, rack or grub screw mechanisms, or suchlike.

The movement means <NUM> can comprise position detection devices, for example position transducers capable of identifying the position of the drawing unit <NUM> in the direction of adjustment Y.

In the example shown in <FIG>, the movement means <NUM> comprise a pair of hydraulic cylinders <NUM>, associated with the support structure <NUM> on one side and with the mobile support <NUM> on the opposite side, able to move the mobile support <NUM> in a sliding way on a pair of guides <NUM>.

Possible position detection devices can also be provided in association or in combination with the feed unit <NUM> so as to coordinate the position of the drawing and straightening unit <NUM>, in particular of the grooves <NUM>, <NUM>, <NUM>, with the position of the feed unit <NUM>, in particular of the guide apertures <NUM>, <NUM>, <NUM>.

According to one possible variant, shown in <FIG>, the feeder body <NUM> of the feed unit <NUM> can be mobile along an axis of alignment Z orthogonal to the axis of feed X and to the direction of adjustment Y.

The feeder body <NUM> can comprise a plurality of guide apertures disposed at different levels on the feeder body <NUM>, the different levels being defined at different heights along the axis of alignment Z.

This variant can be particularly useful in the event that it is necessary to provide to feed a range of very different metal products P, without interrupting the work cycle or replacing the feeder body <NUM>.

According to another variant, at least the feeder body <NUM> of the feed unit <NUM> can also be mobile in a direction of registration substantially parallel to the direction of adjustment Y.

According to some embodiments, a method for drawing and straightening metal products P is provided. The method provides:.

According to one aspect, between the supply step and the drawing step there is provided an adjustment step in which the drawing unit <NUM> is moved in the direction of adjustment Y transverse with respect to the axis of feed X so as to align one or more of the grooves <NUM>, <NUM>, <NUM> with respective metal products P supplied by the feed unit <NUM>.

It is clear that modifications and/or additions of parts or steps may be made to the unit and method for drawing and straightening metal products as described heretofore, without departing from the field and scope of the present invention as defined by the claims.

Claim 1:
Apparatus (<NUM>) for working metal products comprising a drawing and straightening unit (<NUM>) for feeding one or more metal products (P), comprising at least one first roller (<NUM>) provided peripherally with a plurality of circular grooves (<NUM>, <NUM>, <NUM>) configured to accommodate at least one metal product (P), and at least one second roller (<NUM>, <NUM>, <NUM>) opposite said first roller (<NUM>) with respect to an axis of feed (X) of said at least one metal product (P), characterized in that there are adjustment means (<NUM>) associated with said drawing and straightening unit (<NUM>) and configured to move said unit (<NUM>) in a direction of adjustment (Y) transverse with respect to said axis of feed (X) so as to align, in use, one or more of said grooves (<NUM>, <NUM>, <NUM>) with respective metal products (P) fed by a feed unit (<NUM>) disposed upstream, and in that the number of second rollers (<NUM>, <NUM>, <NUM>) is equal to the number of grooves (<NUM>, <NUM>, <NUM>) of the first roller (<NUM>), so that each second roller (<NUM>, <NUM>, <NUM>) is aligned with a respective groove (<NUM>, <NUM>, <NUM>).