The present invention refers to a non-stop unwinding device with limited bulk for unwinding rolls of web-like material.
In numerous industrial applications, for example in the production of paper manufactured goods such as napkins, toilet paper or other items, one is required to feed a generic production line with a web-like material normally obtained by means of unwinding of one roll or several rolls arranged in parallel.
Specific machinery are then available that are capable of supporting one or more large diameter rolls and carrying out their continuous, high-speed unwinding, so as to make the web-like material available for subsequent processing. Normally, such unwinding machinery are also capable of automatically carrying out the joining of webs coming from different rolls, by means of pasting between the end of the web exiting from the roll upon completed unwinding and the end of the web loaded onto the next roll to be unwound, so as to be able to send a continuous and uniform web to the subsequent transformation or processing lines.
On some continuous unwinding devices of traditional type, the rolls of web-like material are arranged in line with respect to each other, with the joining head of the machine placed between the rolls themselves. A similar solution, however, leads to a considerable bulk of the unwinding device in the longitudinal direction.
Particular unwinding devices were then made in which the web-like material rolls are arranged flanking, mounted on substantially horizontal support pins bound to a rotatable vertical arm. When the web present on the unwinding roll is close to finishing, the machine is stopped and the vertical arm is made to rotate 180° in order to present the new roll to the unwinding mechanism. After the ends of the webs being processed are joined, the unwinding machine is then reactivated.
However, the drawback of this type of unwinding device, in addition to requiring a rotating vertical support for flanking rolls, with consequent structural complications, is that of increasing the transverse bulk of the unwinding device itself. This problem should not be underestimated, especially when the unwinding device is installed in a factory upstream of pre-existing equipment for processing the continuous web, which often do not have adequate space around them.
The object of the present invention is therefore to provide a non-stop unwinding device for unwinding rolls of web-like material in which the bulk of the device itself is limited as much as possible, while high functioning reliability is maintained.
Another object of the invention is that of making a non-stop unwinding device with limited bulk for rolls of web-like material in which the joining operation of the ends of the webs coming from the finishing roll and from the next roll is facilitated and rendered as automated as possible.
Still another object of the invention is that of making a non-stop unwinding device with limited bulk for rolls of web-like material that is simple to utilise and economical to make.
These objects according to the present invention are achieved by providing a non-stop unwinding device with limited bulk for rolls of web-like material as set forth in claim 1.
Further characteristics of the invention are highlighted in the subsequent claims.
The characteristics and advantages of a non-stop unwinding device with limited bulk for rolls of web-like material according to the present invention will be more evident from the following exemplifying and non-limiting description, referred to the attached schematic drawings in which:
With particular reference to
Therefore, when the web present on the roll 102 is close to finishing, it is necessary to completely stop the device 100, make the arm 110 rotate 180°, with consequent need to arrange a suitable surrounding space for carrying out such operation, and prearrange the new roll 104 for the subsequent web head joining step. Only at the end of such step can the operator reactivate the device 100.
With reference now to the
At least two rolls 12 and 14 of web-like material are supported on the device 10, arranged flanking in the longitudinal direction of the device 10. More precisely, the support group of the rolls 12 and 14 is composed of a support pin 16 for each roll 12 and 14, the support pins 16 being bound on two opposite sides of a vertical column 18 made integral with the base 20 of the unwinding device 10. The support pins 16 are horizontally extended, in a substantially orthogonal direction to a vertical plane passing through the longitudinal centre axis of the device 10.
The device 10 then comprises, for each of the rolls 12 and 14 to be unwound, an unwinding mechanism 22 adapted to unwind, from the related roll 12 or 14, the web-like material 24 which is normally composed of one sheet (
Each unwinding mechanism 22 is composed, in the illustrated embodiment, by at least one continuous belt 34 placed below the related roll 12 or 14. A gearmotor group 36 maintains the continuous belt 34 in rotation and in contact with the back of the related roll 12 or 14 for facilitating the unwinding of the web-like material 24.
The device 10 also comprises a joining mechanism 26 set to join specific portions of web-like material respectively coming from the roll 12 completing unrolling and the roll 14 ready to begin unrolling.
Advantageously, according to the present invention, the support pins 16 for the rolls 12 and 14 are bound to the vertical column 18 at different respective heights H1 and H2 with respect to the base 20 of the device 10 (
In the illustrated embodiments, the joining mechanism 26 and the vertical column 18 are arranged in a central position, i.e. along the longitudinal centre axis of the unwinding device 10. Such longitudinal centre axis thus results equidistant from the two flanking rolls 12 and 14. Deflection means 28 are then provided downstream of each roller 12 and 14, each comprising return bars 30 tilted with respect to a horizontal plane in order to deflect the web-like material 24 coming from the rolls 12 and 14 and to direct it towards the joining mechanism 26 placed in a central position with respect to the device 10.
During the step of joining the webs on the unwinding device 10 according to the invention, the one-ply or two-ply web-like material 24 coming from one of the rolls 12 being processed, suitably guided by deflection means 28, crosses the joining mechanism 26 where the initial edge (or the two edges, if the roll is two-ply) of the new roll 14 waiting to be processed is retained on a joining pad 32 by means of a suction system 38. Double-sided adhesive tape is extended on such edge, which will paste it to the web exiting from the roll 12 completing unwinding. Normally, in a per se known manner, the junction zone of the web-like material 24 will then be discarded by the subsequent machinery in order to make the finished product.
If two-ply rolls 12 and 14 must be processed, the unwinding device 10 is provided with a joining mechanism 26 (
The sequence of the roll change is the following. When the roll 12 being processed has nearly reached the end, a sensor 42 (
The roll change sequence described up to now can occur in a time equal to about 30 seconds, without having to stop the unwinding device 10. Once the change has occurred, the operator then has a lot of time available for preparing and loading a new roll in the machine, and such new roll's web-like material will later be connected with that of the roll being processed.
It is thus seen that the non-stop unwinding device with limited bulk for rolls of web-like material according to the present invention attains the objects highlighted above, allowing both the reduction of the overall bulk and a greater functioning speed and reliability of the device itself, without requiring stopping in the roll change step.
The non-stop unwinding device with limited bulk for rolls of web-like material according to the present invention thus conceived is in any case susceptible to numerous modifications and variants, all part of the same inventive concept; in addition, all the details can be substituted by technically equivalent elements, while the shapes and sizes can be of any type according to technical requirements.
The protective scope of the invention is therefore defined by the enclosed claims.
Number | Date | Country | Kind |
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MI2007 A001497 | Jul 2007 | IT | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB2008/002019 | 7/23/2008 | WO | 00 | 8/2/2010 |