Bending machine for helically bending an elongated workpiece

A bending machine for helically bending an elongated workpiece, comprising:

• at least three bending rollers that cooperate in bending the elongated workpiece by rotating together with respective supporting shafts having parallel longitudinal axes, each bending roller being configured to shift along its supporting shaft by a prismatic coupling in a limited linear stroke and to swing with respect to the longitudinal axis of the supporting shaft of the respective bending roller by a partially spherical body forming a rotary coupling with the supporting shaft of the respective bending roller in an amount of angular displacement according to an arc of meridian of the partially spherical body so that each bending roller is oriented coplanar to the elongated workpiece that has an inclined position with respect to a longitudinal axis of the bending machine depending on a desired helix pitch,
• wherein each bending roller is made from two half-rollers that are provided with a central space so that each half-roller engages the partially spherical body having a central hole along which the partially spherical body is connected to the supporting shaft of the respective bending roller by the prismatic coupling, and
• wherein said partially spherical body has a pocket configured to house a ball projecting into an inner race defined in the central space of each of the bending half-rollers, the inner race being half closed at ends thereof to prevent the ball from slipping out from the central space, the inner race creating a spherical coupling between said partially spherical body and said bending roller by said ball to limit the amount of angular displacement according to said arc of meridian.