Automatic machine and method for making curvilinear packing boxes

An automatic machine for making curvilinear tubes or boxes covered with paper or cardboard and having a curvilinear outline, having a

• conveyor for conveying to a covering station a tube or a box having a first and a second end, wherein the
• covering station comprises:
• a first sub-station equipped with a spindle, able to engage in the tube or the box and cause it to rotate relative to a horizontal axis, and operating in conjunction with a feeder for linear feed of a pre-glued covering sheet, so as to connect the covering sheet to an outer wall of the tube or the box;
• a second, folding over sub-station equipped with a folding over device operated on command for covering the second, open end of the box with an excess edge of the covering sheet projecting from said second end,
• wherein the folding over device comprises a contact element connected to a carrier to be movable radially with respect to the tube or box engaged by the spindle, from a first position, at a distance from the tube or box, and a second position, wherein the contact element, in the second position, interferes with said excess edge of the covering sheet while the spindle rotates the tube or box about its axis.