PROFILES AND THE LIKE

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 in coils, used in particular to make reinforcements for reinforced concrete, are generally fed by respective reelsin order to be worked in machines equipped with suitable straightening groups. Such straightening apparatuses 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 humps present in the rod and the residual curvature caused by the winding in a coil form. To such end, the straightening members subject the rod to suitable flexure actions with intensities such as to overcome the material elastic limit, 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 apparatuses 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 rod being fed, in a way as to constrain this latter to assume a substantially damped sinusoid profile, which finally assumes a substantially 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 ruining the iron surface that, in the case of the rod for reinforced concrete, must be ribbed and must satisfy precise technical requirements. Both solutions require drawing means to feed the rod being worked.

[5] In a different known solution, illustrated for example in document EP 1952906, the straightening members present inside the rotor are constituted by rollers rotating about axis suitably inclined with respect to the longitudinal feed axis of the rod. 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 hyperbolic rotors the straightening rollers result arranged inclined with respect to the longitudinal feed axis of the iron rod, so that the rotation motion generated by suitable motorization generates an axial component on the iron rod, which is able to cause the axial advancing thereof. The presence of such an axial component makes the hyperbolic rotors intrinsically provided with a system for advancing the iron rod. For this reason, the nowadays hyperbolic rotors straightening apparatuses are not provided with a drawing unit, unlike the inserts rotors. The axial component generated in the hyperbolic rotors turns out to be not very high, so that in order to reduce the drawing effort the motorization of the reels from which the material unwinds has to be frequently used.

[7] In the hyperbolic rotors it is complained about the fact that some slipping is generally caused between the straightening rollers and the iron rod dragged in advancing. This can cause a sensible wear of the straightening rollers, as well as a heat expansion and a considerable stress of the rolling members associated with the straightening rollers.

[8] Another drawback of the straightening apparatuses with hyperbolic rotors is constituted by the fact that the advancing speed of the iron rod does not result usually constant and is substantially uncontrolled. This can easily determine a non precise cutting of the iron rod. All this is heightened in the transient phases such as in starting or braking phase. Because of these drawbacks the hyperbolic rotor has found an application in machines that do not or almost not require stops, so in practice in machines wherein a so-called 'flying' cutting can be applied, so wherein advancing of the iron is not stopped but cutting is made by means of a unit synchronized with the rod motion. Yet this turns out to be problematic in the folding machines, since carrying out the folding without stopping the rod is very difficult. Disclosure of invention

[9] The task of the present invention is that of solving the aforementioned problems, devising a hyperbolic rotor straightening apparatus that allows to obtain a precise and fast feeding of the iron rod.

[10] A further object of the present invention is that of providing a straightening apparatus that allows to render the wear and tear of the rollers minimum.

[11] 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.

[12] 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

[13] 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:

[14] figure 1 shows an axonometric perspective view of a portion of a machine for working the iron rod provided with the straightening apparatus according to the invention;

[15] figure 2 shows a front view of the same machine portion.

Best Modes of Carrying Out the Invention

[16] With particular reference to such figures, the apparatus for straightening iron rods 20 according to the invention is indicated in its entirety with 1. The straightening apparatus 1 comprises at least a rotor unit 2 suitable to be driven in rotation about the own longitudinal axis A, under control of motor members of known type, not shown. The rotor unit 2 provides a hollow body 3, arranged according to the above-mentioned longitudinal axis A, suitable to define inits own interior an axial cavity along which is driven in advancing the iron rod 20 to be straightened. The hollow body 3 of the rotor unit 2 is borne rotating at the opposite ends by a couple of supports 5 through the interposition of rolling means. The supports 5 are fixed to the fixed frame 6 of the apparatus.

[17] The rotor unit 2 is suitable to house, in suitable seats defined in its own interior, a plurality of straightening members 4 constituted by grooved rollers. The straightening rollers 4 are arranged in a suitable sequence in correspondence of a substantially central portion of the rotor unit 2 and are rotating, in a known way, on respective pins eccentric to the longitudinal axis A of the rotor unit 2. In particular, the straightening rollers 4 are arranged preferably in alternative mode from opposite parts with respect to the cited longitudinal axis A, in a way as to act alternatively on opposite surfaces of the iron rod that crosses the rotor unit 2. The axis of each roller 4 is preferably arranged on a plane inclined with respect to the longitudinal axis of the rotor unit 2.

[18] An auxiliary drawing unit 7 is associated withand arranged in line with the rotor unit

2. The drawing unit 7 is equipped with couples of wheels 8, 9 suitably motorized through motor units 12 suitable to cause the feed of the iron rod 20 along the longitudinal axis A. In the illustrated case, the drawing unit 7 provides two couples of wheels 8, 9 arranged in series, with the axis orthogonal to the feed direction A of the iron rod; but it is possible to use differently shaped drawing units of known type.

[19] More precisely, the driving wheels 8 of the drawing unit 7 result operated in rotation at the same angular speed, while the wheels 9 coupled to the preceding ones result driven. The driven wheels 9 are subjected to an opening mechanism 10, operated by a suitable actuator unit 11. The opening mechanism 10 is suitable to move the driven wheels 9 between a drawing position set to the driving wheels 8 and a distanced position for inserting the iron rod to put in working.

[20] It is to note that, in the case illustrated as an example, the apparatus provides a first and a second rotor unit 2, arranged respectively upstream and downstream to the auxiliary drawing unit 7 and suitably counter-rotating. Obviously it is possible to provide, according to the requirements, the use of a single rotor unit 2, arranged upstream or downstream to the aforesaid drawing unit 7.

[21] The functioning of the apparatus for straightening iron rods and the like according to the invention turns out to be easy to understand from the preceding description.

[22] During the normal functioning of the apparatus, the rotor unit 2 is driven in rotation and by means of the straightening rollers 4 acts on the iron rod 20 that crosses longitudinally the cavity of the hollow body 3 of the rotor 2. The iron rod 20 is made advancing by the drawing unit 7 that through the couples of driven wheels 8, 9 engages the same iron rod 20.

[23] The described apparatus attains the scope of providing a straightening apparatuswith hyperbolic rotor, that allows to obtain a precise and fast feed of the iron rod.

[24] A characteristic of the straightening apparatus in hand is that of rendering the wear and tear of the straightening members minimum. In fact the presence of the auxiliary drawing unit allows to practically cancel, or at least to reduce at the minimum, the possible slipping between the straightening members of the hyperbolic rotor and the iron rod. This makes the straightening bodies less worn. As a consequence the production of heat turns out to be minimum and the support bearings of the same straightening members less stressed.

[25] The presence of the auxiliary drawing unit allows to feed the iron rod at a substantially faster speed than the one normally used in the traditional hyperbolic rotors. [26] Moreover the auxiliary drawing unit allows to have a constant speed of advancing of iron rod, in a way as to assure the precision of the successive cutting process. In practice the apparatus in hand warrants the perfect adherence to the operating conditions provided and so products having a high qualitative level. In this way bigger accelerations can be subjected to the rod.

[27] A further important advantage of the apparatus consists in the fact that it is possible to avoid any motorization for the reels, which on the contrary is necessary in the use of traditional hyperbolic rotors, with a sensible reduction of the overall costs of the plant.

[28] Eventually, the straightening apparatus according to the invention allows to overcome the technical prejudice for which the traditional hyperbolic rotors do not provide the use of fixed drawing means, the drawing function being carried out by the same straightening members.

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

[30] 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.