Plastic moulded box with compactible structure, of improved type

A plastic molded box having an articulated compactible structure comprising:

• a rectangular bottom (1) having a perimeter frame (12) and at least one ear (10) formed on the rectangular bottom;
• an upper frame (2);
• two opposite transversal walls (3), each hingedly connected to the upper frame (12);
• two opposite longitudinal walls (4), each wall being formed from an upper rectangular panel (4a) and a lower rectangular panel (4b), the rectangular panels (4a and 4b) overlapping one another;
• each upper panel (4a) being connected by first hinges (15) to each lower panel (4b), each upper panel (4a) further being connected by second hinges (6) to the upper frame (2), each lower panel (4b) further being connected by third hinges (7) to the lower frame (12);
• each third hinge (7) having an opposite coaxial pair of pins (6) disposed on the respective lower panel (4b);
• a housing (8) formed on the at least one ear (10) on the rectangular bottom (1), the pins (9) on each third hinge (7) being inserted in the housing (8);
• longitudinal partitions (11) disposed immediately beside the third hinge (7) and protruding from the rectangular bottom (1);
• a vertical groove (12) formed internally on each third hinge (7), each vertical groove extending above the opposite pair of pins (9), each vertical groove having a bottom;
• a wedge-shaped protuberance (13) formed on the bottom of each vertical groove, each wedge-shaped protuberance creating friction against the longitudinal partitions (11) when the longitudinal walls are folded inside the box.