The technical characteristics of the invention, according to the above object, are clearly set forth in the appended claims, and the advantages thereof will result more evident from the detailed description that follows, with reference to the attached drawings, of an embodiment to be considered a non-limiting example thereof. In the drawings:
With reference to the attached drawings, a winder 1 for reeling continuous web material from a feeding unit comprises a winding cylinder 13 having an axis “X”, preferably motor-driven by at least one electric motor and fixed to a bedplate 5, and a rod-holder structure 4 of rigid or semi-rigid type.
In the described example, the structure 4 comprises an end “f” for engagement with a winding rod 2, and an end “g” hinged to the cylinder 13 for rotation of the arm 3 which carries the rod 2, at least one elastic element 7 being interposed between the engagement end “f” and the hinged end “g” of structure 4.
The element 7, according to the invention, protects the structure 4 against possible contact pressures greater than a preset value “P” that may occur from accidental events or anomalous operating conditions.
In a preferred solution, shown in
In this exemplary embodiment, the component 6 is linked respectively, to the primary arm 3 via an equilizer 18 having two hinges “a” and “b”, and to the oscillating arm 11 via the hinge “d”.
Mounted on one end of the oscillating arm 11 is a locking/unlocking clamp 12 of substantially C-shape intended to retain or release the rod 2 during the winding.
The clamp 12 is connected to the oscillating arm 11 via a rigid support 15 of cylinder-piston type for the opening/closing of the clamp 12 and the consequent blockage or release of rod 2.
In this embodiment, the primary arm 3 is connected at a point 17 to a second linear actuator 8, preferably driven by one or more brushless motors 10 connected to one or more reducers 9, to drive into rotation the arm 3 which carries the rod 2.
In the embodiment illustrated with reference in particular to
Preferably, the protective elastic element 7 is an air spring which has the advantage of allowing the user to exactly establish the rigidity of the structure 4 by simply increasing or reducing the internal pressure thereof.
The elastic element 7 is of basic importance both for absorbing the vibrations generated upon normal use and, in particular, for all those critical situations in which there is occurrence of stress peaks, such as upon a passage of foreign bodies of large dimensions between the cylinder 13 and the reel in the course of formation which, by generating a sudden displacement of the latter, is cause for stress peaks in all the winder. The rigidity of the spring 7 shall be evaluated by the user in base of the breaking load of the weaker component, so as to establish a pressure threshold. By establishing said pressure threshold, two distinct operating modes of the spring 7 must be verified, in particular, when the latter is subjected to pressures below said threshold, the spring 7 must have a rigid behaviour, whereas for higher pressures it must compress itself by allowing the rod-holder structure 4 to partially accomodate the sudden displacement of the reel in the course of formation.
This second operating mode occurs, for example, upon all those extraordinary conditions in which the loads transmitted to the structure result greater than the breaking load of the weaker component.
Advantageously, the primary arm 3 is driven by a second component 8 having a rigid behaviour, at least when subject to bending, such component being preferably a hydraulic jack driven by one or more brushless motors 10 connected to an equal number of reducers 9.
Shown with reference to
The present invention obtains important advantages. A first advantage lies in the fact that the use of the elastic element 7 makes it possible to provide a high protection of the mechanical structure under critical operating conditions, such as when the feeding web breaks up.
In fact, it is well known that during the winding operation of web material at high speed, a tear of the feeding web is likey to occur with consequent formation of a “bundle” of material which, as it is dragged along by the movement of the reel in the course of formation, is squeezed between the same reel and the winding cylinder 13.
This brings about a sudden displacement of the reel away from the cylinder 13, and the transmission of high loads on the whole winder 1 through the rod-holder structure 4, which loads, owing to the rigidity of the same structure, overstrain the individual components. This possible drawback is likely to cause serious damages to the structure 4 of the winder 1.
The use of an elastic element 7 which reacts by a compression thereof upon a sudden displacement of the reel in the course of winding, allows preventing any stress peak in the whole winder 1.
This advantage results more evident if the elastic element 7 is an air spring, since, as previously indicated, the use of this type of elastic element 7 allows the user to accurately regulate its rigidity.
It will be appreciated that the thus conceived invention is suited for industrial application, numerous modifications and variants being possible within the scope of the inventive idea, and all the parts being possibly replaced with technically equivalent elements.
Number | Date | Country | Kind |
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FI2006A000201 | Aug 2006 | IT | national |