Device and method for guiding and directing a metal sheet in a bending machine to obtain frustoconical structures

Device for guiding and directing a metal sheet in a bending machine to form continuously a frustoconical structure, said device comprising:

• resting and contrasting arrangement extending along a closed path, and suitable for restingly receiving a longitudinal edge of said metal sheet and contrasting a movement of said edge in a direction that is transverse to a preset advancement trajectory of said metal sheet,
• a supporting body for said resting and contrasting arrangement, having at least one oblong lateral portion that is suitable for facing said edge and configured for conforming said resting and contrasting arrangement to the longitudinal profile of said edge so as to obtain an extended zone of contact with said edge and impress contrasting pressure distributed along said edge,
• said supporting body consisting of several reciprocally connected parts, the reciprocal position of said parts being variable by adjusting arrangement so as to modify the geometrical shape of said supporting body to adapt the shape of the closed path of said resting and contrasting arrangement to the longitudinal geometric profile of said edge of the metal sheet,
• said resting and contrasting arrangement being movable around said supporting body along said closed path to accompany said edge of the metal sheet by a distributed contact devoid of relative sliding and rolling, so as to impose on said metal sheet the movement along said preset advancement trajectory to and through said bending machine.