Process and machine for reducing the height of boxes with a square or rectangular cross section

A method for reducing a height of a box formed of a flexible material, the box having a bottom and at least four sidewalls extending to a level of a top of a stack of objects previously placed into the box, the four sidewalls including two length sidewalls that are parallel to a length dimension of the box and two width sidewalls that are parallel to a width dimension of the box, the reduction of the height of the box being greater than a half-width of the box, the method comprising:

• making a horizontal score in each of the sidewalls of the box at a height substantially equal to the top of the stack of objects so that a distance between the top of the stack of objects and a top of the box is greater than the half-width of the box;
• making two oblique scores in an upper part of each of two of the length sidewalls, each of the oblique scores having one end located at a level of one end of the horizontal score and another end located at a level of an upper edge of one of the length sidewalls such that the oblique score forms an angle substantially equal to 45° to a horizontal plane;
• folding the upper part of each of the length sidewalls toward a center of the box around the horizontal score at an angle substantially equal to 90° until the upper parts of the length sidewalls between the oblique angles overlap each other and are at an angle substantially equal to 180°, wherein the folding of the upper parts of the length sidewalls includes differentiating inclination angles of the upper parts of the length sidewalls before the upper edges of the length sidewalls meet so that, when the upper parts of the length sidewalls meet, the upper edge of the upper part of one of the length sidewalls covers the upper edge of the other of the length sidewalls and the upper parts of the length sidewalls slide one over the other;
• and
• folding an upper part of each of the width sidewalls toward the center of the box around the horizontal score at an angle substantially equal to 90°,
• wherein, prior to folding the upper part of each of the length sidewalls, the upper edges of the two length sidewalls are substantially the same distance from the bottom of the box;
• wherein, during the step of folding the upper parts of the length sidewalls, the upper edge of the upper part of one of the length sidewalls is first diverted downwardly by a deflector and simultaneously the upper edge of the upper part of the other length sidewall is diverted upwardly by the deflector, the deflector retracting under a pushing force of at least one of the upper edges so that the upper edges do not interfere with each other and that center flaps of the upper part of the length sidewalls are folded back at an angle substantially equal to 90° and overlap each other partially in a substantially horizontal plane at the end of the folding.