Weft feeder with turn separator including multiple diameter swift

A weft feeder with turn separator, for air jet looms, the weft feeder comprising:

• a variable-diameter drum for supporting multiple turns of thread deposited on the drum by a windmilling arm, said turns forming a weft reserve;
• and a variable-diameter swift which includes multiple rods having an undulatory motion and protruding, in a cyclic manner, from corresponding slots of the drum to transport the turns of thread from the base of the drum to its head, and wherein the extent of the protrusion of the rods from the slots of the drum determines the mutual distance between the turns of the thread reserve;
• wherein said swift and said drum are formed by corresponding sectors that are independently radially movable and controlled by respective radial shifting mechanisms, each of which comprises at least one actuation gear that meshes with individual shifting gears for shifting the respective drum and swift sectors;
• wherein the actuation gears of said radial shifting mechanism are turned by a single transmission element which is controlled by an actuation knob and which couples in sequence to both actuation gears, through respective slots defined in said actuation gears, after said knob moves through respective idle angular motions having different values;
• the difference between said idle angular motions of the transmission element being used to vary the extent of the protrusion of the turn transporting rods, with respect to said sectors of the drum, to correspondingly adjust the distance between said turns.