Cardboard box having a centring tab, blank, set of blanks and method for producing such a box

A blank or set of blanks made of corrugated cardboard sheet intended to form a box having a polygonal section comprising lateral walls, an upper wall that is used to form the top of the box and that is connected to at least two of the lateral walls by first fold lines and a lower wall used to form the bottom of the box, said blank including at least one tab straddling at least one of said first fold lines, and linked on one side to the upper wall by a first join line and on the other side to the adjacent lateral wall by a second join line, said join lines being parallel to said first fold line, said at least one tab having two lateral sides crossing said first fold line and being cut along said lateral sides,

• said at least one tab also having an intermediate parallel fold line offset towards the center of the box in relation to said first fold line, such that the at least one tab forms a portion projecting from the upper face of the upper wall during folding of the lateral wall in relation to the upper wall,
• and the bottom of the box having at least one perforated surface portion arranged to cooperate with said projecting portion, and to be aligned with said projecting portion when the box is formed, and to engage with the projecting portion of a box below, characterized in that the at least one tab is a centering tab and the perforated surface portion is a recess matching the shape of said at least one tab, the edges of the recess of a box formed with said blank being arranged to cooperate in contact with the lateral peripheral edges of said tab of a box below formed using such a blank, wherein the lateral peripheral edges of the at least one tab have a cavity defining shoulders and arranged to cooperate in contact with a matching cavity in the recess of a box above.

A method comprising:

• forming, from a blank or set of blanks made of corrugated cardboard sheet, a box having a polygonal section comprising lateral walls, an upper wall forming the top of the box and connected to at least two of the lateral walls by first fold lines and a lower wall forming the bottom of the box, characterized in that given that said box includes at least one tab straddling at least one of said first fold lines and linked on one side to the upper wall by a first join line and on the other side to the adjacent lateral wall by a second join line, said join lines being parallel to said first fold line, said at least one tab having two lateral sides crossing said first fold line and being cut along said lateral sides,
• said at least one tab also having an intermediate parallel fold line that is offset towards the center of the box in relation to said first fold line, such that the at least one tab forms a portion projecting from the upper face of the upper wall during folding of the lateral wall in relation to the upper wall
• and the bottom of the box having at least one perforated surface portion arranged to cooperate with said projecting portion, and to engage with the projecting portion of a box below, characterized in that the at least one tab is a centering tab and the perforated surface portion is a recess matching the shape of said at least one tab, the edges of the recess of the box being arranged to cooperate in contact with the lateral peripheral edges of said tab of the box below, wherein the lateral peripheral edges of the at least one tab have a cavity defining shoulders and arranged to cooperate in contact with a matching cavity in the recess of a box above.