Device for inverting the shoulder of a container having at least one deformable shoulder

A method of inverting a container shoulder, the method comprising:

• providing a filled and capped container to a device,
• wherein the device comprises at least one framework through which a conveyor conveying containers along a path between an inlet and an outlet is configured to extend and on which there is mounted an arm bearing a belt stretched between at least three pulleys, the pulleys comprising a driving pulley, a driven pulley, and a squashing pulley extending between the driving pulley and the driven pulley such that the belt has an upper strand and a lower strand which extends in line with the conveyor, said lower strand comprising a squashing segment that extends between the driven pulley and the squashing pulley and forms an angle of between 1.5° and 5° with respect to a horizontal plane, and a pressure reducing segment that extends between the squashing pulley and the driving pulley and forms an angle of between −2° and −7° with respect to the horizontal plane,
• wherein the container comprises a body of substantially frustoconical shape which extends along a main axis X, a shoulder at an upper end of the body, the shoulder continuing into a neck, and a bottom, the shoulder being articulated between at least two stable positions:
• an extended position in which the shoulder protrudes from the body, and a retracted position in which the shoulder is at least partially retracted into the body or extends at a same level as an upper end of the body;
• transporting the container in the extended position on the conveyor to the inlet;
• and
• compressing the container, by exerting a downward pressure on the cap with the squashing segment, such that a central section of the shoulder is turned about an internal articulation of the shoulder, thereby inverting the shoulder.