Machine for packaging mattresses in a sheet unwound continuously from a roll

A machine for packaging a mattress in a sheet which is unwound continuously from a feeder roll, the machine comprising:

• a horizontal supporting surface for said mattress;
• a horizontal receiving surface;
• guiding means for guiding said sheet in a substantially vertical direction which passes between said supporting surface and said receiving surface, so that by moving said mattress in an advancement direction from said supporting surface toward said receiving surface said sheet is arranged over and under said mattress;
• joining and cutting means for joining and cutting said sheet, upstream of said mattress, along said advancement direction, and for forming a bag which wraps around said mattress in a loop;
• unwinding assemblies for unwinding said sheet from said feeder roll, which comprise two rollers movable along said receiving surface, said rollers being actuatable with an outgoing stroke, in said advancement direction, and with a return stroke, said rollers being articulated about vertical axes to rotate to rotate between an alignment position, in which the rollers are perpendicular to the advancement direction and a position in which the rollers are parallel to said advancement direction and to the sides of said mattress;
• and actuation means for actuating said rollers to reach said alignment position, upstream of said sheet while said mattress is arranged on the supporting surface and to maintain said position during said outgoing stroke and transfer of the mattress from the supporting surface onto the receiving surface, in order to allow said rollers to engage and stretch said sheet over and under the mattress, and to return to said position in which they are parallel to the advancement direction after the mattress has been transferred onto said receiving surface, in order to allow said rollers to disengage from said sheet and return to said position for engaging said sheet.