Unwinder, in particular for unwinding reels of paper, semi-automatic plant comprising such unwinder and process for unwinding reels

An unwinder for unwinding reels of paper, said unwinder comprising:

• a supporting structure partially closed and defining an internal space suitable for unwinding at least one reel;
• said supporting structure comprising:
• a first lateral support;
• a second lateral support spaced from said first lateral support;
• a crosspiece interposed above and between the first and the second lateral support, said crosspiece defining with said first lateral support and second lateral support, said partially closed structure;
• said unwinder further comprising:
• a first axial unwinding system placed at the first lateral support and configured to axially unwind a first reel of the at least one reel;
• a second axial unwinding system placed at the second lateral support and configured to unwind a second reel of the at least one reel;
• a joining device placed at the crosspiece and configured to make a joint between a first ply belonging to the first reel and a second ply belonging to the second reel to perform a reel exchange;
• said second axial unwinding system being configured to load said second reel from a loading zone after said first reel being unwound on said first axial unwinding system reaches a first predetermined diameter;
• said joining device being configured to make said joint between said first reel and said second reel when the first reel reaches a second predetermined diameter smaller than said first predetermined diameter;
• said second axial unwinding system being configured to unwind said second reel after said joint has been made, said first axial unwinding system being configured to interrupt the unwinding of said first reel after said second axial unwinding system has started unwinding the second reel,
• wherein
• said first axial unwinding system comprises two first arms coupled together and movably associated with the first lateral support;
• said second axial unwinding system comprises two second arms coupled together and movably associated with the second lateral support;
• each pair of said first and second arms being configured to lift the first reel or the second reel placed in the loading zone and to rotate it to unwind it axially, and wherein the first lateral support comprises:
• a first upright for each first arm, each first upright extending in a vertical direction;
• each first arm being slidably constrained to the respective first upright;
• first sliding guides extending in a transverse direction and to which each first upright is slidably constrained at the ends;
• and the second lateral support comprises:
• a second upright for each second arm, each second upright extending in a vertical direction;
• each second arm being slidably constrained to the respective second upright;
• second sliding guides extending in a transverse direction and to which each second upright is slidably constrained at the ends.