Device and process for handling and controlling the yarn of a crosswinding head of a crosswinding machine during the starting operations of a new lot

The invention relates to a device and process for handling and controlling the yarn (2) in a crosswinding head of a crosswinding machine during the starting operations of a new lot, said crosswinding machine being equipped with a series of crosswinding heads and at least one service trolley (16), wherein the end of the yarn (2) of a new pirn is collected by the suction mouth (7) on the pirn (1) side and delivered to the joining device (9), from where it is, in turn, collected by the suction mouth (8) on the side of the bobbin and, after the suction mouth (8) has rotated until it is close to the driving and traversing cylinder (6), engaging the yarn (2) on its back during the movement, which is transferred from this to the handling device (15) of the service trolley (16).