FIELD OF THE INVENTION

The present invention relates to the technical sector concerning deformation of flat metal bars, i.e. having a rectangular section, for obtaining spirals. In particular, the invention relates to an apparatus for deforming a metal bar up to obtaining a spiral.

DESCRIPTION OF THE PRIOR ART

A known apparatus for deforming a metal bar, up to obtaining a spiral, is shown in figures 1 and 2, wherein: figure 1 is a view from above of the apparatus, in which some components have been removed to better evidence others; while figure 2 is a view along section ll-ll of figure 1. The apparatus comprises: a frame (2); a first deforming member (6) which has a conical or truncoconical shape, wherein the relative lateral truncoconical surface (4) forms a first angle (a) with respect to the relative base (5); a second deforming member (7) which has a conical or truncoconical shape, in which the relative lateral truncoconical surface (4) forms the aforementioned first angle (a) with respect to the relative base (5); the first deforming member (6) and the second deforming member (7) are both arranged and activatable in rotation with respect to the axis thereof so that a metal bar inserted between the truncoconical surface of the first deforming member (6) and the truncoconical surface of the second deforming member (7) is drawn by the first deforming member (6) and the second deforming member (7) and deformed up to obtaining a spiral. For reasons of simplicity, figure 1 does not illustrate the motors drawing the first deforming member (6) and the second deforming member (7) in rotation with respect to the axis thereof, nor is the metal bar illustrated, which during use of the apparatus is inserted between the truncoconical surface of the first deforming member (6) and the truncoconical surface of the second deforming member (7). As a function of the rotation direction of the first deforming member (6) and of the second deforming member (7), the spiral obtained can be left- or right-hand. It should also be specified that the first deforming member (6) and the second deforming member (7) are usually arranged horizontally and in such a way that the relative rotation axes coincide at the vertices of the relative ideal cones.

Further, figure 1 does not illustrate the presence of a further pair of auxiliary cones, which are usually present and engage the metal bar once it has been deformed by the first deforming member (6) and the second deforming member (7), enabling a regulating of the pitch and diameter of the spiral under formation. These auxiliary cones are instead illustrated in figure 3 con reference to the apparatus according to the present invention.

The above-mentioned known-type apparatus further comprises a first support member (21) which rotarily bears the first deforming member (6) in order to enable free rotation of the first deforming member (6) with respect to the axis thereof; As can be noted from figure 2, the apparatus comprises in particular a first shaft (41) which is solidly constrained to the first deforming member (6); the first shaft (41) is directly rotarily coupled to the first deforming member (6) and is drawn in rotation by motors which, as already mentioned, have not been illustrated. The first support member (21 ) is in turn rotarily coupled with the frame (2) by means of a first pin (51) and a second pin (52) which are fixed to the frame (2), in order to enable regulating the angular position of the first deforming member (6) with respect to the second deforming member (7) as a function of the transversal dimensions of the metal bar (3) to be deformed; in other words, in order to insert a metal bar between the truncoconical surface of the first deforming member (6) and the truncoconical surface of the second deforming member (7) it is necessary to perform a rotation in a clockwise direction of the first support member (21) so as to distance the first deforming member (6) from the second deforming member (7), insert the metal bar (3) between the first deforming member (6) and the second deforming member (7) and then rotate the first support member (21) in the anti-clockwise direction up to locking the metal bar (3) between the truncoconical surface of the first deforming member (6) and the truncoconical surface of the second deforming member (7).

In order to regular the angular position of the first deforming member (6) with respect to the second deforming member (7), according to the above-described procedures, the apparatus further comprises the following regulating unit (38): a first electric motor (23); a third screw (24) drawn in rotation by the first electric motor (23); a third nut screw (25) which engages with the third screw (24); a first arm (26) which is hinged to the third nut screw (25); a third pin (53) fixed to the frame (2); a second arm (28) which is hinged to the first arm (26), at a relative first end, and which is hinged to the third pin (53), at a relative second end; a fourth pin (54) which is fixed to the second end of the second arm (28); a third carriage (30) which is slidingly coupled with the first support member (21) and which rotarily engages with the fourth pin (54). The first electric motor (23) can rotate the third screw (24) in one or the other direction, which respectively determines a nearing or a distancing of the first deforming member (6) relative to the second deforming member (7). When the first electric motor (23) is inactive, the first support member (21) cannot rotate; therefore the regulating unit (38) also implements first blocking means (31) for blocking the position of the first support member (21) with respect to the frame (2) when the apparatus is in use.

The apparatus further comprises a second support member (not visible in figure 1) which rotarily bears the second deforming member (7) in order to enable free rotation of the second deforming member (7) with respect to the axis thereof.

The known-type apparatus described in the foregoing can deform metal bars or stainless steel bars. In the case of iron bars, experience has taught that these are deformed optimally using an apparatus in which the first deforming member (6) and the second deforming member (7) have the first angle (a) of fifty five degrees, which corresponds to an angle of the vertex of the cone of the first deforming member (6), and the second deforming member (7) of seventy degrees. Instead, in the case of stainless steel metal bars, it is has been shown to be optimal to use a first deforming member (6) and a second deforming member (7) in which the relative lateral truncoconical surface (4) forms a second angle with respect to the relative base (5) which is sixty degrees, which corresponds to an angle of the vertex of the cone of the first deforming member (6) and the second deforming member (7), also sixty degrees.

At present, producers of spirals who wish to obtain iron spirals or stainless steel spirals are obliged to have to different apparatus, a first apparatus in which the first deforming member and the second deforming member have a first angle of fifty five degrees and a second apparatus in which the first deforming member and the second deforming member have a second angle of sixty degrees. Having two apparatus requires much space and significantly increases costs.

SUMMARY OF THE INVENTION In the light of the above, the aim of the present invention consists in obviating the above-cited drawbacks.

The aim has been attained by means of an apparatus for deforming a metal bar up to obtaining a spiral, according to claim 1.

The possibility of rotating and translating the second support member with respect to the frame advantageously makes possible the use of the apparatus with two different pairs of deforming members, the first pair of deforming members can be constituted by the first deforming member and the second deforming member and the first angle can be fifty five degrees, so as to make the production of iron spirals optimal; while the second pair of deforming members can be constituted by the third deforming member and the fourth deforming member and the second angle can be sixty degrees, so as to make the production of stainless steel spirals optimal. On the basis of the type of metal bar to be deformed, therefore, either iron or stainless steel, it is sufficient to mount the most suitable pair of deforming members; if the type of material of the metal bar changes (from iron to stainless steel or vice versa), then it will be sufficient to distance (with a roto-translation) the second support member from the first support member, replace the pair of deforming members and newly re-near (with another roto- translation) the second support member to the first support member.

In general, the first angle and the second angle can also be different to fifty five degrees and sixty degrees. The type of material the metal bar is made of can also be different to iron and stainless steel.

BRIEF DESCRIPTION OF THE DRAWINGS Specific embodiments of the invention will be described in the following parts of the present description, according to what is set down in the claims and with the aid of the appended tables of drawings, in which:

- figure 1 is a view from above of an apparatus of known type, in which some components have been removed to better evidence others; - figure 2 is a view along section line ll-ll of figure 1 ;

- figure 3 is a view from above of an apparatus for deforming a metal bar up to obtaining a spiral, object of the present invention;

- figure 4 is a larger-scale view of detail k of figure 3;

- figures 5-8 are respectively three lateral views and a perspective view of the apparatus of figure3, in which a first set of the components has been omitted better to evidence others;

- figures 9-10 are two views from above of the apparatus of figure 3, in which the first set of components and a second set of components have been omitted better to evidence others, and wherein figure 9 illustrates the apparatus in which the deforming members have an angle, between the lateral conical or truncoconical surface and the base, of fifty five degrees, while figure 10 illustrates the same apparatus in which the deforming members have been replaced with other deforming members having the above-cited angle of sixty degrees;

- figures 11-15 are respectively a lateral view, two perspective views, a partly- exploded perspective view and a view from above of the apparatus of figure 3, in which the first set of components and a second set of components have been omitted better to evidence others;

- figure 16 is a view along section line XVI-XVI of figure 11 ;

- figures 17, 18, 19 are respectively the views of sections XVII-XVII, XVIII-XVIII and XIX-XIX of figure 15; - figure 20 is a view from above of figure 3, in which the first set of components, the second set of components and a third set of components have been omitted better to evidence others; further, a continuous line shows two deforming members in which the angle between the lateral conical or truncoconical surface and the base is fifty five degrees, while a broken line shows two deforming members in which the angle is sixty degrees.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to figures from 3 to 20, reference numeral (1) denotes in its entirety an apparatus for deforming a metal bar (3) up to obtaining a spiral (15), object of the present invention, which comprises: a frame (2); a first deforming member (6) which has a conical or truncoconical shape, wherein the relative lateral conical or truncoconical surface (4) forms a first angle (a) with respect to the relative base (5); a second deforming member (7) which has a conical or truncoconical shape, wherein the relative lateral conical or truncoconical surface (4) forms the aforementioned first angle (a) (figures 9, 10) with respect to the relative base (5); the first deforming member (6) and the second deforming member (7) being both arranged and activatable in rotation with respect to the axis thereof so that a metal bar (3) inserted between the lateral conical or truncoconical surface (4) of the first deforming member (6) and the lateral conical or truncoconical surface (4) of the second deforming member (7) is drawn by the first deforming member (6) and the second deforming member (7) and deformed up to obtaining a spiral (15); a first support member (21) which rotarily bears the first deforming member (6) in order to enable free rotation of the first deforming member (6) with respect to the axis thereof, the first support member (21) being in turn coupled rotarily to the frame (2) in order to enable regulating the position of the first deforming member (6) with respect to the second deforming member (7) as a function of the transversal dimensions of the metal bar (3) to be deformed; first blocking means (31) for blocking the position of the first support member (21) with respect to the frame (2) when the apparatus (1) is in use; a second support member (22) (figures 16, 17, 19) which rotarily bears the second deforming member (7) in order to enable free rotation of the second deforming member (7) with respect to the axis thereof; wherein the second support member (22) is rotarily and slidingly coupled to the frame (2) in such a way that by replacing: a first deforming member (6) with a third deforming member (8) which has a conical or truncoconical shape (figure 10), wherein the relative lateral conical or truncoconical surface (4) forms a second angle (b), different to the first angle (a) with respect to the relative base (5); and the second deforming member (7) with a fourth deforming member (9) which has a conical or truncoconical shape (figure 10), wherein the relative lateral conical or truncoconical surface (4) forms the second angle (b) with respect to the relative base (5), a metal bar (3) inserted between the lateral conical or truncoconical surface (4) of the third deforming member (8) and the lateral conical or truncoconical surface (4) of the fourth deforming member (9) can be drawn by the third deforming member (8) and the fourth deforming member (9) and be deformed up to obtaining a spiral (15); second blocking means (32) for blocking the position of the second support member (22) with respect to the frame (2) when the apparatus (1 ) is in use.

As is known, a cone is obtained by rotating a right-angled triangle about a relative first leg by three hundred and sixty degrees, in the following, the first angle (a) (figure 9) or the second angle (b) (figure 10) will be considered to be the angle defined between the base (5) of the cone (which contains the second leg of the right-angled triangle) and the lateral surface of the cone (hypotenuse of the right-angled triangle); the angle of the vertex of the cone (denoted in the following as the third angle (c) (figure 9) or as the fourth angle (d) (figure 10) is instead equal to double the angle defined between the hypotenuse and the first leg. Although the first deforming member (6) can also have a truncoconical shape, reference will continue to be made to the corresponding cone.

As a function of the rotation direction of the first deforming member (6) and of the second deforming member (7), the spiral (15) which obtained can be left- or right- hand; figures 3 and 4 illustrate a spiral (15) having a right-hand formation.

The first deforming member (6) and the second deforming member (7) are preferably arranged horizontally so that the relative axes coincide in a point which is the vertex of the cones of the first deforming member (6) and the second deforming member (7); likewise the third deforming member (8) and the fourth deforming member (9) (figure 10) are preferably arranged horizontally so that the relative axes coincide in a point which is the vertex of the cones of the third deforming member (8) and the fourth deforming member (9).

The second support member (22) rotates relative to a first rotation axis (A), which is preferably vertical.

The first support member (21) rotates relative to a second rotation axis (A), which is preferably vertical. With reference to figure 9, the first angle (a) can be fifty five degrees, which corresponds to a third angle (c) of the vertex of the cone of the first deforming member (6), and the second deforming member (7) can be seventy degrees. In this figure, for the sake of simplicity the metal bar (3) is not illustrated and the lateral conical or truncoconical surface (4) of the first deforming member (6) contacts the lateral conical or truncoconical surface (4) of the second deforming member (7), with the consequence that the rotation axis of the first deforming member (6) forms an angle of seventy degrees with the rotation axis of the second deforming member (7). In this configuration, the apparatus (1 ) can optimally deform a metal bar (3) made of iron.

Instead, with reference to figure 10, the second angle (b) can be sixty degrees, which corresponds to a fourth angle (d) of the vertex of the cone of the first deforming member (6) and the second deforming member (7) of sixty degrees. In this figure, for the sake of simplicity the metal bar (3) is not illustrated and the lateral conical or truncoconical surface (4) of the third deforming member (8) contacts the lateral conical or truncoconical surface (4) of the fourth deforming member (9), with the consequence that the rotation axis of the third deforming member (8) forms an angle of sixty degrees with the rotation axis of the fourth deforming member (9). In this configuration, the apparatus (1) can optimally deform a metal bar (3) made of stainless steel.

By way of example, the base (5) of the first deforming member (6) and of the second deforming member (7) can have a diameter of 230mm; the distance measured between the conjoining line of the rotation axes of the first deforming member (6) and the second deforming member (7) (which conjoining line coincides with the vertex of the cones of the first deforming member (6) and the second deforming member (7)) on the one hand, and the first rotation axis (A), on the other hand, can be 556mm. the distance measured between the conjoining line of the rotation axes of the first deforming member (6) and the second deforming member (7) on the one hand, and the second rotation axis (B), on the other hand, can be 1205mm.

Again by way of example, and in the hypothesis that the first angle (a) is fifty five degrees (figure 9): the angle comprised between the rotation axis of the first deforming member (6) and the translation direction (C), wherein the second support member (22) translates with respect to the frame (2) can be twenty degrees; on the other hand, the angle comprised between the rotation axis of the second deforming member (7) and the translation direction (C) can be ninety degrees. Still by way of example, substituting the first deforming member (6) with the third deforming member (8) and the second deforming member (7) with the fourth deforming member (9), and in a case where the second angle (b) is sixty degrees (figure 10), then: the first rotation axis (A) can be translated along the translation direction (C), and towards the first deforming member (6) and the translation direction (C), by 89mm; the angle comprised between the rotation axis of the first deforming member (6) and the translation direction (C) can now be twenty two degrees; on the other hand, the angle comprised between the rotation axis of the second deforming member (7) and the translation direction (C) can now be eighty two degrees.

The apparatus (1 ) preferably comprises a first guide (61 ) (figure 19) that is fixed to the frame (2) and a first carriage (71 ) that engages in the first guide (61 ) and which forms a first coupling surface (81 ), in which the second support member (22) forms in turn a second coupling surface (82) which couples with the first coupling surface (81 ) of the first carriage (71 ) in such a way that the second support member (22) can be drawn by the first carriage (71 ) along the first guide (61 ) in a translation direction (C) and can rotate with respect to the first carriage (71 ) with respect to a first rotation axis (A) (see figures 17 and 19).

The apparatus (1 ) preferably comprises a first nut screw (1 1 ) which is solidly constrained to the first carriage (71 ) and a first screw (12) which engages in the first nut screw (11) and which is activatable in rotation so as to move the first carriage (71) (figures 17 and 19).

The apparatus (1 ) preferably comprises a second guide (62) that is fixed to the frame (2) and a second carriage (72) that engages in the second guide (62) and which forms a third coupling surface (83); the second support member (22) forms in turn a fourth coupling surface (84) which couples with the third coupling surface (83) of the second carriage (72) in such a way that the second support member (22) can be drawn also by the second carriage (72) along the second guide (62) in the translation direction (C) and can rotate with respect to the second carriage (72) with respect to the first rotation axis (A), wherein the first guide (61), the second guide (62), the first carriage (71 ), the second carriage (72) and the second support member (22) are arranged with respect to one another in such a way that the second support member (22) is interposed between the first guide (61 ) and the first carriage (71 ), on one side, and the second guide (62) and the second carriage (72) on the other side. In particular, the first guide (61 ) and the first carriage (71 ) are inferiorly arranged with respect to the second guide (62) and to the second carriage (72), see figures 17, 19.

The apparatus (1 ) preferably comprises a second nut screw (13) which is solidly constrained to the second carriage (72) and a second screw (14) which engages in the second nut screw (13) and which is activatable in rotation so as to move the second carriage (72) (figures 17 and 19). The apparatus (1 ) preferably comprises first motor means, for example a fourth electric motor (48), a first mechanical connection (35) for activating the first screw (12) by means of the first motor means, and a second mechanical connection (36) for activating the second screw (14) by means of the first motor means, the first motor means, the first mechanical connection (35) and the second mechanical connection (36) being configured such that the first screw (12) and the second screw (14) are drawn in rotation in a synchronous way. This is advantageous as it enables a regular advancement of the second support member (22) along the translation direction (C). In particular, the first mechanical connection (35) and the second mechanical connection (36) can comprise respectively a first transmission belt (35) and a second transmission belt (36).

In the embodiment illustrated in the figures (see figures 17 and 19), the first coupling surface (81 ) is a cylindrical protuberance and the second coupling surface (82) is a cylindrical recess fashioned in the second support member (22); alternatively (an embodiment not illustrated) the second coupling surface (82) can be a cylindrical protuberance and the first coupling surface (81 ) can be a cylindrical recess fashioned in the first carriage (71).

In the embodiment illustrated in the figures (once more see figures 17 and 19), the third coupling surface (83) is a cylindrical protuberance and the fourth coupling surface (84) is a cylindrical recess fashioned in the second support member (22); alternatively (an embodiment not illustrated) the fourth coupling surface (84) can be a cylindrical protuberance and the third coupling surface (83) can be a cylindrical recess fashioned in the second carriage (72).

The apparatus (1 ) preferably comprises a first pusher member (18) which acts against the second support member (22) in order to rotate the second support member (22) with respect to the first rotation axis (A) in a first rotation direction, for example in a clockwise direction with respect to a view from above of the apparatus (1 ) (figures 16, 20), and a second pusher member (19) which acts against the second support member (22) in order to rotate the second support member (22) with respect to the first rotation direction (A) in a second rotating direction that is opposite the first rotation direction, i.e. in an anti-clockwise direction with respect to a view from above of the apparatus (1 ) (figures 16 and 20). The apparatus (1 ) can comprise a fifth electric motor (57) which activates the first pusher member (18): in this case, the first pusher member (18) can be partly threaded and the apparatus (1 ) can further comprise a fourth nut screw (64), solidly constrained to the frame (2), which engages with the first pusher member (18) and projectingly supports the fifth electric motor (57), see figures 16, 20. The second pusher member (19) can be a pneumatic cylinder. The combined action of the first pusher member (18) and of the second pusher member (19) implements the second blocking means (32), figures 16, 20. To regulate the angular position of the first deforming member (6) with respect to the second deforming member (7), the apparatus (1 ) can further comprise the following regulating unit (38), se in particular figure 16 or figure 1 : a first electric motor (23); a third screw (24) which is drawn in rotation by the first electric motor (23); a third nut screw (25) which engages with the third screw (24); a first arm (26) which is hinged to the third nut screw (25); a third pin (53) fixed to the frame (2); a second arm (28) which is hinged to the first arm (26), at a relative first end, and which is hinged to the third pin (53), at a relative second end; a fourth pin (54) which is fixed to the second end of the second arm (28); a third carriage (30) which is slidingly coupled with the first support member (21 ) and which rotarily engages with the fourth pin (54). The first motor can rotate the third screw (24) in one or the other direction, which respectively determines a nearing or a distancing of the first deforming member (6) relative to the second deforming member (7). When the first electric motor (23) is inactive, the first support member (21 ) cannot rotate; therefore the regulating unit (38) also implements first blocking means (31) for blocking the position of the first support member (21 ) with respect to the frame (2) when the apparatus (1 ) is in use. The first deforming member (6) can be drawn in rotation by a second electric motor (43), by means of a third transmission belt (42). The chassis of the second electric motor (43) is preferably solidly constrained to the first support member (21 ), see for example figure 5. The second deforming member (7) can be drawn in rotation by a third electric motor (45), by means of a fourth transmission belt (47). The chassis of the third electric motor (45) is preferably solidly constrained to the second support member (22).

Figure 4 illustrates the metal bar (3) inserted between the lateral conical or truncoconical surface (4) of the first deforming member (6) and the lateral conical or truncoconical surface (4) of the second deforming member (7).

The apparatus (1) can comprise a further pair of auxiliary cones (16) (figure 3), which are usually present and engage the metal bar (3) once it has been deformed by the first deforming member (6) and the second deforming member (7), enabling a regulating of the pitch and diameter of the spiral (15) under formation. As can be noted from figure 18, the apparatus (1 ) can comprise in particular a first shaft (41) which is solidly constrained to the first deforming member (6); the primo shaft (41 ) is directly rotarily coupled to the first deforming member (6) and is drawn in rotation by the second electric motor (43), as can be observed in figures 5, 7, 8.

The first support member (21 ) can in turn be rotarily coupled with the frame (2) by means of a first pin (51 ) and a second pin (52) which are fixed to the frame (2), in order to enable regulating the angular position of the first deforming member (6) with respect to the second deforming member (7) as a function of the transversal dimensions of the metal bar (3) to be deformed, see figure 18; in other words, in order to insert a metal bar (3) between the lateral conical or truncoconical surface (4) of the first deforming member (6) and the lateral conical or truncoconical surface (4) of the second deforming member (7) (this can occur when the reel of metal bar in use in the apparatus runs out, or when it is necessary to replace the metal bar in use in the apparatus with a metal bar of a different thickness, but the same material) it is possible to perform a rotation in a clockwise direction of the first support member (21) so as to distance the first deforming member (6) from the second deforming member (7), inserting the metal bar (3) between the first deforming member (6) and the second deforming member (7) and then rotating the first support member (21) in anticlockwise direction up to locking the metal bar (3) between the lateral conical or truncoconical surface (4) of the first deforming member (6) and the lateral conical or truncoconical surface (4) of the second deforming member (7).

The frame (2) can comprise a lower plate (55), to which the first pin (51 ) and the first guide (61 ) are fixed, and an upper plate (56), to which the second pin (52) and the second guide (62) are fixed. As can be noted from figures 17 and 19, the apparatus (1 ) can comprise in particular a second shaft (34) which is solidly constrained to the second deforming member (7); the second shaft (34) is directly rotarily coupled to the second deforming member (7) and is drawn in rotation by the third electric motor (45), as can be observed in figures 5-8. The first electric motor (23), the second electric motor (43), the third electric motor (45), the fourth electric motor (48) and the fifth electric motor (57) can be coupled with gear reducers, illustrated in the figures.

It is understood that the foregoing has been described by way of non-limiting example, and any eventual constructional variants are understood to fall within the protective scope of the present technical solution, as claimed in the following.