DEVICE AND METHOD FOR UNWINDING AND INSPECTION OF METALLIC STRIP COILS

Abstract

The invention relates to a device for unwinding a coil of a metal strip including a bogie translatable back and forth along a guiding system; a blocking system which is arranged on said bogie and which contains a first and a second shaped element, wherein the first shaped element is a roller, preferably an idle roller; an actuating system for modifying the distance between the two shaped elements, for defining an intercepting position and a gripping position of the strip; and an element for detaching the strip from the coil provided on the first shaped element. A relative method of unwinding and inspecting a metal strip is also described, in particular used to check the state of wear of rolling cylinders used for producing the inspected strip.

Claims

1. Device A device for unwinding a coil of a metal strip comprising: (a) a bogie and a guiding system wherein the bogie is translatable back and forth along the guiding system; (b) a blocking system which is arranged on said bogie and which contains a first shaped element and a second shaped element; (c) an actuating system for modifying the distance between said first and second shaped elements for defining an intercepting position of a strip end between said two shaped elements when spaced and a gripping position of said strip end by said two shaped elements when close together; and (d) an element for detaching said strip end from the coil provided on the first shaped element, wherein said first shaped element is a roller and wherein said second shaped element is preferably a second roller.

2. The device according to claim 1, wherein said first and said second shaped element are rollers.

3. The device according to claim 1, wherein said roller(s) is/are an idle roller(s).

4. The device according to claim 1, wherein the element for detaching the strip end from the coil, during use, is adapted to position itself against the coil once the first shaped element comes into contact therewith.

5. The device according to claim 1, wherein the element for detaching the strip end from the coil is selected from a plate, a blade, a pin.

6. The device according to claim 1, wherein said actuating system is arranged on said bogie.

7. The device according to claim 1, wherein said actuating system comprises a pivotable arm, on which said second shaped element is mounted, and a mechanism for changing the orientation of said arm, preferably a pneumatic or hydraulic cylinder.

8. The device according to claim 1, it further comprising: (a) a rotatable mandrel; and/or (b) support rollers, wherein, during use, a coil of a metal strip is wound on said mandrel and/or placed on said support rollers and wherein the mandrel and/or at least one support roller can be actuated.

9. An inspection plant of a metal strip from a coil comprising: (i) an unwinding device according to claim 1; (ii) an inspection plane, placed along said guiding system, for placing the unwound strip.

10. The inspection plant according to claim 9, further comprising: (iii) an analysis device placed above said inspection plane adapted to provide data on the surface quality of a strip resting on said inspection plane.

11. A method for unwinding a metal strip from a coil comprising the following steps: (I) approaching a coil of a metal strip and an unwinding device according to claim 1, wherein the strip end is placed at a height lower than the height of the first shaped element and the second shaped element and wherein the opening angle between the strip end and the coil opens upwards; (II) spacing the shaped elements; (III) positioning the first shaped element and the element for detaching said strip end from the coil against the coil; (IV) rotating the coil so as to carry the strip end upwards and to insert it between the first and the second shaped element; (V) approaching the second shaped element to the first shaped element so as to grasp the strip end between both components of the blocking system; and (VI) translating the bogie along the guiding system and rotating the coil unwinding the metal strip therefrom, wherein step (II) and step (III) can reverse the order within the sequence of steps.

12. The method for unwinding a metal strip from a coil according to claim 11, wherein in step (VI) the unwound strip is preferably placed on an inspection plane and in that it comprises a further step: (VII) wherein the inner surface of the unwound strip is inspected for its surface quality.

13. The method for unwinding a metal strip from a coil according to claim 11, wherein in step (V) the approach of the first shaped element and the second shaped element occurs with the actuating system comprising a pivotable arm, on which the second shaped element is mounted, and a mechanism for changing the orientation of said arm, comprising at least one of a pneumatic or hydraulic cylinder.

14. The method for unwinding a metal strip from a coil according to claim 11, wherein the surface quality of the inspected strip is used for assessing the wear of rolling cylinders used for producing the inspected strip.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0058] FIG. 1 shows a first system for unwinding metal strips from coils according to the prior art;

[0059] FIG. 2 shows a second system for unwinding metal strips from coils according to the prior art;

[0060] FIG. 3 shows an inspection system of metal strips according to the invention with a particular coil unwinding system; and

[0061] FIGS. 4A-4E show the succession of various steps of the coil unwinding method according to the invention for the surface inspection of the unwound strip.

DETAILED DESCRIPTION

[0062] FIGS. 1 and 2 representing the prior art have already been initially explained.

[0063] FIG. 3 will instead be described below. It shows a system for inspecting coils of metal strips according to the invention with a particular coil unwinding system. A coil 12 of a metal strip is wound on an axis or motorized mandrel 10. The coil 12 is housed on two support rollers 13 of which at least one can be motorized, while the other is preferably idle. As a function of the rotation direction of the mandrel 10 and/or the motorized support roller 13, the mandrel and/or the support roller winds or unwinds the strip forming the coil 12. Next to the coil 12, a roller path or a series of parallel rollers 29 for inspecting the unwound strip is envisaged. Only one strip end 14, or tail, which is slightly detached from the coil 12, is noted in the present figure. Along the inspection table 29 there are guides 28 along which a bogie 30 moves. The bogie 30 is provided on the side pointing towards the coil 12 with a strip detachment element 20 which is associated with an idle roller 16. At about the same height as the idle roller 16, a second idle gripping roller 18 is mounted to a pivoting arm 21 which can be actuated by a pneumatic or hydraulic cylinder 22. The rotation of the pivoting arm 21 causes the idle roller 18 to be approached to the other idle roller 16 so as to trap the tail of the strip 14 in the middle.

[0064] FIGS. 4A to 4E show the sequence of the various steps of unwinding a coil according to the invention for the surface inspection of the unwound strip in which the system shown in FIG. 3 is applied. The reference numbers correspond to those of FIG. 3.

[0065] In the first step (FIG. 4A), the coil 12 is positioned on the support rollers 13 so that the strip end 14 is (with the coil seen in section) in the 4 o'clock position with the strip end 14 indicating towards the blade-shaped detachment element 20. The bogie 30 is in the waiting position with the idle gripping roller 18 open or spaced from the first idle roller 16.

[0066] In step two (FIG. 4B), the bogie 30 moves along the guide 28 towards the coil 12 to bring the roller 16 into contact with the side surface of the coil 12. The detachment element or the strip detachment tip is positioned, being associated with the roller 16, independently against the coil 12.

[0067] In the third step (FIG. 4C), at least one support roller 13 and/or the mandrel 10 rotate to unwind the strip from the coil 12 and insert the strip end 14 between the unwinding roller 16 and the gripping roller 18.

[0068] Subsequently, in step four (FIG. 4D), the pneumatic or hydraulic cylinder 22 pushes the pivoting arm 21 to grasp the strip end 14 between the unwinding roller 16 and the gripping roller 18, approaching the second 18 to the first 16.

[0069] In the final step five (FIG. 4E), the bogie 30 then moves backwards in the direction of the arrow B and accompanies the strip end 14 and thus the entire strip during its unwinding carried out by the mandrel 10 and/or by a motorized support roller 13. The unwound strip 14 extends on the roller path 29 and its inner surface (i.e., the concave surface which in the rolled state indicated towards the inside of the coil 12) is available for inspection (arrow V).

[0070] After the inspection, the above operations will be carried out in reverse order, to roll the strip back on the coil 12, i.e., the bogie 30 moves towards the coil 12, the support roller 13 and/or the mandrel 10 rotate in the opposite direction to support the winding of the strip 14, when the bogie 30 has again reached the coil 12, the second roller 18 is distanced from the first roller 16 by the movement of the cylinder 22, the strip 14 exits the space between these two rollers 16 and 18, the bogie 30 and therewith the detachment element 20 and the relative idle roller 16 detach from the coil 12.