Shape-retaining hoist type rectangular parallelepiped bag having multistage configuration

A shape-retaining hoist type rectangular parallelepiped bag comprising:

• a rectangular parallelepiped bag that is substantially rectangular parallelepiped-shaped and that has an internal space to accommodate an accommodated object;
• a bottom surface holding mechanism holding a bottom surface of the rectangular parallelepiped bag by application of a first tensile force to the bottom surface;
• a side surface holding mechanism holding side surfaces of the rectangular parallelepiped bag by application of a second tensile force to the side surfaces;
• a central hanging body extending in a vertical direction, one end of the central hanging body being fixed to a center of the bottom surface of the rectangular parallelepiped bag, the central hanging body holding the bottom surface holding mechanism and the side surface holding mechanism at first and second intermediate positions thereof in the vertical direction, respectively;
• and
• a ring-shaped hook holding portion connected to the other end of the central hanging body, the ring-shaped hook holding portion being configured to be attached to a hook,
• wherein the bottom surface holding mechanism includes at least four hanging bodies,
• one ends of the at least four hanging bodies are respectively fixed at positions of the bottom surface that are respectively spaced apart from the center of the bottom surface by predetermined distances on diagonal lines connecting between opposed apexes of the bottom surface,
• the other ends of the at least four hanging bodies are connected to the first intermediate position of the central hanging body,
• the side surface holding mechanism includes a plurality of side surface restriction bodies,
• horizontal components of vectors of the plurality of side surface restriction bodies extend in directions different from those of the at least four hanging bodies when viewed along the vertical direction,
• one ends of the plurality of side surface restriction bodies are fixed to the side surfaces,
• the other ends of the plurality of side surface restriction bodies are connected to the second intermediate position of the central hanging body, and
• the first intermediate position and the second intermediate position of the central hanging body are spaced apart from each other, and the second intermediate position is located closer to the other end of the central hanging body than the first intermediate position.