Clamping system of special conductors for a stator or rotor bar winding for an electric machine

Process for clamping special conductors for a stator or rotor bar winding for an electric machine during a twisting step of said special conductors and/or during a step of picking up the special conductors from a twisting device, comprising the steps of:

• (a) providing a clamping system of the special conductors comprising a system axis (T-T) and a plurality of grippers aligned or adapted to be aligned along a circumference lying on a plane substantially perpendicular to the system axis (T-T), each gripper including a pair of jaws or holding arms;
• (b) moving each gripper along a respective sliding direction (R) transversal to the system axis (T-T) from a relatively set back position with respect to the system axis (T-T) towards a relatively advanced position with respect to the system axis (T-T) to clamp on two opposite sides a portion of at least one of said special conductors;
• (c) moving said pair of arms in a plane transversal to the system axis (T-T) so as to bring together such arms to make the gripper take up an operative clamping configuration, in which said holding arms are relatively closer together to clamp on two opposite sides said portion of at least one of said special conductors;
• (d) moving each gripper in a sliding manner along said sliding direction (R) from said advanced position towards said set back position to release said portion of special conductor;
• and
• (e) moving said pair of arms in the plane transversal to the system axis (T-T) so as to spread apart such arms to make the gripper take up an operative release configuration in which said holding arms are relatively farther apart to release said portion of the special conductor;
• wherein each of said grippers comprises a gripper body slidably mounted along said sliding direction (R) transversal to the system axis (T-T), the gripper body including a body portion to which said holding arms are hinged and being suitable for taking up said position relatively more advanced towards the system axis (T-T) when the gripper-takes up said clamping configuration, and said position relatively more set back with respect to said advanced position when the gripper takes up said release configuration;
• and
• said clamping system comprising closing elements and opening elements of the arms of the grippers, said closing elements comprising a forced passage arranged frontally to each pair of holding arms and suitable for engaging such arms during the sliding of the gripper body towards said advanced position to make the gripper take up said clamping configuration, and said opening elements comprising elastic elements connected to said pair of holding arms and suitable for spreading apart such arms while the gripper slides towards said set back position leaving the forced passage so as to allow the gripper to take up said release configuration.