APPARATUS FOR STRAIGHTENING METAL PROFILES AND THE LIKE AND METHOD FOR ADJUSTING STRAIGHTENING MEMBERS IN SUCH AN APPARATUS

Technical field

[1] The present invention regards an apparatus for straightening metal profiles, for example iron rods and the like. Background Art

[2] It is known that iron rods, used in particular to make reinforcements for reinforced concrete, are generally fed by respective reelsin order to be worked in machines provided with suitable straightening apparatus. Such straightening apparatus are usually provided with a series of operating members suitable to act on the iron rod being fed before it reaches the successive working stations, for example the cutting station and sometimes successively the folding station. Practically, such apparatuses are suitable to eliminate the residual curvature caused by the winding as a coil. To such end, the straightening members subject the rod to suitable flexure actions with intensities such as to overcome the elastic limit of the material, so as to substantially eliminate the residual curvature and to render the straightening effect permanent.

[3] Nowadays various typologies of apparatuses for straightening iron rods are known.

According to a widely known typology, illustrated for example in documents EP 0459869 and EP 0947256, the straightening apparatus comprises one or more straightening units constituted of couples of counter-rotating wheels, suitably grooved, opposite with respect to the axis of the rod, in order to suitably engage the same rod fed therebetween. The counter-rotating wheels are arranged in succession and with parallel axis. As an example such apparatus of the known type can be provided with a first straightening unit and a second straightening unit, suitable to correct prevalently corresponding components of the curvature of the iron rod, in particular on perpendicular planes, for example on a horizontal plane and on a vertical one. The counter-rotating wheels gradually correct the curvature of the rod, acting from opposite sides with respect to the advancing rod, in a way as to constrain this latter to assume a substantially damped sinusoid profile, which finally assumes a rectilinear trend.

[4] In a different typology of straightening apparatus, the straightening members are inserted inside a rotating member or rotor, suitable to be driven in rotation about an axis coinciding substantially with the rod feed direction. According to a known solution, illustrated as an example in the documents EP 0880415 and EP 1952906, the straightening members used in such rotors are constituted of inserts or reeds radially distributed inside the rotor, in a way as to act by rotating flexure on the crossing iron rod. Practically, each straightening element compresses and drags on the rod as consequence of the rotating motion of the rotor, consequently correcting the rod residual curvature in every lying plane. Nevertheless such types of apparatus have the drawback of requiring frequent substitutions of the straightening members, because of the considerable friction produced in the relative motion between the inserts or reeds and the rod to be straightened.

[5] In a different known solution, illustrated for example in document EP 1952906, the straightening members present inside the rotor are constituted by rollers or bushings rotating about axis suitably inclined with respect to the rod longitudinal feed axis. In these rotors, further said hyperbolic, the straightening members roll on the external surface of the rod to be straightened, so as to considerably reduce the wear and tear effects deriving from the friction.

[6] In the typologies of rotor straightening apparatuses, the adjustment of the straightening members constitutes a crucial and in the meantime problematic aspect. Such adjustment is in fact made necessary any time the straightening action performed by the straightening members has to be corrected, further than any time the profile of the rod being worked is changed, thus passing to different diameters and mechanical characteristics. The adjustment substantially requires modifying, in a suitable way, the sinusoidal course imposed to the rod, suitably adjusting the position of the straightening members, in order to assure an efficient compensation of the residual curvatures which appear along the longitudinal unwinding of the rod being worked.

[7] Nowadays, in order to modify the position of the straightening members, the complete stop of the rotor is usually required. By effect of non negligible masses driven in rotation, the respective inertia can determine an advancing motion out of control of the rod to be straightened, rendering the execution of any adjustment intervention very difficult. In any case, the stop of the rotor weighs very unfavourably upon the productive efficiency of the working line.

[8] It is further to note that in known apparatuses the adjustment is often solely confided to operator's experience, to whom is required not only to identify the specific straightening members on which it is necessary to intervene in order to obtain the wanted correction, but also to determine the adjustment entity. Given the considerable role carried out by the intervention and by the evaluation of the operator involved from time to time, it is easy to understand how difficult it is to maintain constant the qualitative standards of the straightening operation results. It is further to note that any time the rod has to be changed it is necessary to stop the productive cycle in order to completely open the straightening apparatus and insert the new iron rod. In particular, the opening of the straightening apparatuses of the known type is made necessary by the fact that it would not be possible to execute otherwise the insertion thereof, also because of the sinusoidal trend of the course imposed to the rod. Disclosure of Invention

[9] The task of the present invention is that of solving the aforementioned problems, devising a rotor apparatus for straightening iron rods and the like that allows to automatically perform the adjustment of the straightening members during the very functioning of the rotor.

[10] Another object of the present invention is that of providing an apparatus that allows to facilitate the introduction of the rod in the rotor.

[11] A further scope of the present invention is to provide an apparatus for straightening iron rods and the like that allows to set the automatic adjustment of the straightening elements on the basis of the only physical and dimensional characteristics of the rod to be straightened and to facilitate the extraction manoeuvre of the rod being worked as well as the insertion of the new one.

[12] Another scope of the present invention is that of providing an apparatus for straightening iron rods and the like having a simple conception, a securely reliable functioning and versatile use, as well as relatively economic cost.

[13] The above mentioned scopes are attained, according to the present invention, by the apparatus for straightening iron rods and the like according to claim 1. Brief Description of the Drawings

[14] Details of the invention shall be more apparent from the detailed description of a preferred embodiment of the apparatus for straightening iron rods and the like according to the invention, illustrated for indicative purposes in the attached drawings, wherein:

[15] figure 1 shows an axonometric perspective view of the apparatus according to the invention;

[16] figures 2 and 3 respectively show a lateral and a plant view of the same apparatus;

[17] figure 4 shows a longitudinal section view of the apparatus according to the trace plane IV-IV in figure 2;

[18] figure 5 shows a transverse section view of the apparatus according to the trace plane

V-V in figure 2;

[19] figure 6 shows a section view of a detail of the same apparatus according to the trace plane VI-VI in figure 3. Best Modes of Carrying Out the Invention

[20] With particular reference to such figures, the apparatus for straightening iron rods wherein the adjustment device 10 is applied is indicated in its entirety with 1. The apparatus 1 comprises a rotor unit 2 suitable to be driven in rotation aboutits own longitudinal axis A, under control of motor members of known type, not represented. The rotor unit 2 provides a hollow shaft 3, arranged according to the above-mentioned longitudinal axis A, suitable to define in its own interior an axial cavity 30 along which is fed the iron rod to be straightened. The rotor unit 2 is borne rotatable at the opposite ends by a couple of supports 5 through the interposition of rolling means 6. The supports 5 are fixed to the fixed frame of the apparatus.

[21] The rotor unit 2 is suitable to internally house a plurality of straighteningmembers 4, preferably constituted of inclined and suitably profiled rollers, shaped with a so-called 'hyperbolic' profile. Alternatively the straightening members 4 can be constituted of insert-shaped wear-resistant metal elements, also suitable to be driven in rotation by the rotor unit 2 during the feed of the iron rod to be straightened.

[22] The rollers 4 are arranged in suitable sequence according to a substantially tangential configuration with respect to the rod being worked and are rotatable on respective pins 40 eccentric to the rotor unit 2 longitudinal axis A, as better described in the following. In particular, the rollers 4 are arranged preferably in alternated way at opposite sides with respect to the cited longitudinal axis A, so as to act alternatively on opposite surfaces of the crossing iron rod. The axis of each roller 4 is preferably arranged on a plane inclined with respect to the longitudinal axis of the rotor unit 2 (see figures 3 and

4).

[23] The adjustment device 10 is suitable to perform the adjustment of the radial positioning of the rollers 4 with respect to the longitudinal axis A of the rotor unit 2. The adjustment device 10 comprises a control unit 11 constituted of a linear actuator member, for example of the oil-pressure or pneumatic type, having a fixed portion 13 and a mobile portion 14; the mobile portion 14 is suitable to be handled in a direction parallel to the longitudinal axis A of the rotor unit 2. The fixed portion 13 is constrained to a stem 15 arranged laterally to the rotor unit 2 and fixed at the ends to the support means 5 through a couple of support arms 16. The mobile portion 14 of the actuator member 11 is articulated by means of a pin 17 with stirrup connection means 18 for connecting to a unit 12 for transmitting the adjustment motion to the rollers 4. The pin 17 is preferably coupled to the connection means 18 through interposition of spherical coupling means 19 (see fig. 6).

[24] The connection means 18 are integral to an arm 20 which is constrained at one side to a short guide tube 21, mounted sliding on the stem 15, and at the other side to a sleeve 22 which is part of the aforesaid adjustment motion transmission unit 12. The short tube 21 is suitable to longitudinally guide the linear shifting of the mobile portion 14 of the actuator member 11. The sleeve 22 is inserted coaxial externally to the hollow shaft 3 of the rotor unit 2 through interposition of rolling means 23, so as to allow the rotation of the same rotor unit 2. Particularly, the rolling means 23 externally engage a collar 24 inserted sliding on the hollow shaft 3, to transmit the axial motion operated under control of the actuator member 11. The collar 24 is constrained to countermeans 25 suitable to transform the axial motion of the same collar 24 into a radial motion of each roller 4, to approach or move awayfrom the longitudinal axis A of the rotor unit 2.

[25] The countermeans 25 comprise a couple of rods 26 suitably guided, in laterally opposite directions, along the rotor unit 2. Each rod 26 is connected to the second collar 25 through suitable coupling means 27, for example constituted of a plaque constrained through suitable screw means. More precisely, each rod 26 is laterally fit to the central body 3a of the rotor unit 2. In correspondence with such central body 3a the rotor unit 2 is box-shaped, in order to allow the housing of the rollers 4. More precisely, each roller 4 is pivoted on a respective pin 40 to a box frame 29 arranged inside the central body 3a of the rotor unit 2 (fig. 5). Between the roller 4 and the internal wall of the box frame 29 faced thereto is defined a passageway clearance 35 for the iron rod being worked.

[26] The box frame 29 is inserted in the rotor unit 2 sliding in radial direction. On the opposite sides the box frame 29 has coaxial seats, suitable to be engaged by a couple of guide pins 31 according to an axis transversal to the longitudinal axis of the rotor unit 2. The guide pins 31 cross the side walls of the rotor unit 2, in correspondence with suitable eyelets 33 with perpendicular expansion to the longitudinal axis A, and are articulated to respective levers 32. The levers 32 are further articulated to the rods 26 in order to receive the longitudinal motion operated by the actuator member 11 and transform it into radial motion of the guide pins 31 and therefore of the rollers 4. The adjustment of the radial positioning of the rollers 4 occurs preferably in contrast of the elastic spring means 36, interposed between the box frame 29 and an internal wall of the rotor unit 2 (see again fig. 5).

[27] In alternative to what described, the countermeans 25 can provide a couple of rod- shaped means connected through respective cam members to the support means of the straightening members 4, having rollers or inserts, mobile in radial direction with respect to the longitudinal axis A of the rotor unit 2.

[28] The functioning of the apparatus for straightening iron rods and the like according to the invention is as follows.

[29] During the normal functioning of the apparatus, the rotor unit 2 is operated in rotation and through the straightening rollers 4 acts on the rod which longitudinally crosses the axial cavity 30. When adjusting the radial positioning of the rollers 4 is necessary, the eccentric pin 40 of the rollers 4 is approached or sent away in a determined way with respect to the longitudinal axis A of the rotor unit 2. To such end, the actuator member 11 is activated in a way as to provoke a predetermined longitudinal shift of the mobile portion 14, correlated to the desired radial adjustment. As a consequence the sleeve 22 associated with the mobile portion 14 of the actuator member 11 results operated in axial direction, so as to drag concordantly the collar 24 and the rods 26. As consequence of the articulation to the levers 32, in their turn articulated to the rods 26, the guide pins 31 shift along the eyelets 33 in radial direction, making the desired adjustment. It is to note that the levers 32 are articulated to the rods 26 in hinge points 37 arranged in a way as to transmit to the rollers 4 concordant radial shifts, of approach or removal from the longitudinal axis of the rotor unit 2.

[30] The described apparatus attains the scope of automatically performing the adjustment of the straightening elements during the functioning of the rotorunit. Such result is substantially due to the transformation of the linear control motion produced by the actuator member 11 in longitudinal direction into a corresponding radial shift of the straightening rollers 4.

[31] In practice the kinetic transmission of the adjustment motion does not require the stop of the apparatus but can occur during the normal functioning of the same, so while the rotor unit 2 is operated in rotation. This is due to the peculiar kinetic chain which originates from the actuator member 11 and ends in correspondence of each roller 4 inside of the same rotor 2. Such a kinetic chain allows the operating members controlled by the actuator member 11 to control the adjustment of the straightening rollers 4 without taking part in the rotation of the rotor unit 2.

[32] An important advantage of the apparatus in hand consists in the fact of facilitating the extraction of the iron rod being worked and, also, the insertion of a new iron rod to be worked. In fact, controlling the deviation of the rollers 4 to the longitudinal axis of the rotor unit 2, the passageway clearance of the iron rod is increased, facilitating the crossing. On the contrary, straightening the rod only requires to operate the adjustment shift in the opposite direction, in a way as to accentuate the sinusoidal trend of the straightening course. As a consequence the extraction and insertion operations can be performed in very short times, to the advantage of the productive yields of the entire rod working cycle.

[33] It is further to note that the apparatus in hand assures perfectly repeatable straightening cycles so having high qualitative level. In fact for any typology of rod to be worked it is possible to associate and so memorize an optimal adjustment typology. In practice, by associating suitable elaboration means with the device in hand, it is possible to set each productive cycle according to predetermined adjustment rules. Therefore the productive result of any single productive cycle turns out not to be constrained by the subjective determinations of the single operator in charge of the apparatus. On the contrary the straightening cycle adjustment parameters can be predetermined in a repetitive way for every working cycle and any rod typology.

[34] It is to observe that in the preceding description reference was made preferably to the application of the adjustment device on apparatuses provided with straightening rollers rotors. But the same solution can be advantageously applied also to straightening apparatuses of different type, in particular provided with reed or insert rotors.

[35] In practice, the embodiment of the invention, the materials used, as well as the shape and dimensions, may vary depending on the requirements.

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