A reversing system for reversing a packing box, an upper surface of which is opened, and from which products are withdrawn, such that a lower surface of the reversed empty packing box is disposed above. A first conveyor transfers an empty packing box, an upper surface of which is opened, from a position at which products are withdrawn from the packing box to a position at which the packing box is reversed. A turning device holds the packing box to be turned about a horizontal rotation axis, and reverses the packing box. A second conveyor carries the reversed packing box to a position at which the bottom surface is opened. The turning device holds two sides, facing each other, among sides of the packing box, and turns and reverses the packing pox using a portion between the holding locations of the two held sides as a rotation axis.

A reversing system for reversing a packing box, an upper surface of which is opened, and from which products are withdrawn, such that a lower surface of the reversed empty packing box is disposed above. A first conveyor transfers an empty packing box, an upper surface of which is opened, from a position at which products are withdrawn from the packing box to a position at which the packing box is reversed. A turning device holds the packing box to be turned about a horizontal rotation axis, and reverses the packing box. A second conveyor carries the reversed packing box to a position at which the bottom surface is opened. The turning device holds two sides, facing each other, among sides of the packing box, and turns and reverses the packing box using a portion between the holding locations of the two held sides as a rotation axis.

A heat-treatment installation with a plurality of transport lines disposed one above the other, trays with two wheels and a latch, lifts for lifting a tray from a lower transport line to another upper transport line, rails on which the trays travel, and transmission belts with counter-latches cooperating with the latches of the trays where, at each lift, each rail has a gate arranged to open when a tray is raised and to close when the tray is above the rail.